@inproceedings{SchiedermeierRettnerSteineretal., author = {Schiedermeier, Maximilian and Rettner, Cornelius and Steiner, Marcel and M{\"a}rz, Martin}, title = {Dual-inverter control synchronization strategy to minimize the DC-link capacitor current}, series = {2020 IEEE Vehicle Power and Propulsion Conference (VPPC), 18 November 2020 - 16 December 2020, Gijon, Spain}, booktitle = {2020 IEEE Vehicle Power and Propulsion Conference (VPPC), 18 November 2020 - 16 December 2020, Gijon, Spain}, publisher = {IEEE}, doi = {10.1109/VPPC49601.2020.9330921}, pages = {1 -- 6}, abstract = {This paper proposes the possible switching synchronization strategies of an automotive dual-inverter against the background of minimizing the RMS DC-link capacitor current. The publication mainly focuses on the straight-ahead motion of a rear axle with one electric drive per wheel. In addition to it, a dual-inverter consisting of two subinverters with a common DC-link capacitor is taken into consideration. These sub-inverters each have three phases and are based on a 2-level voltage-source-topology. To control the electrical machines, the continuous Space-Vector-Modulation strategy is used. For this application, different control signal synchronization strategies of the two sub-inverters of the dualinverter are presented. Apart from the existing strategies, this paper proposes a new method, which inherits a compromise between low complexity and high effectiveness. In contrast to previous publications, the resulting capacitor currents are quantified and subsequentlyevaluated. This novel quantification, which is dependent on the dual-inverter's operating point, provides a base for targeted dimensioning of the capacitor. Moreover, this forms the foundation for further investigations of vehicle's cornering, as well as for the possible synchronization of stand-alone inverters. In the context of this publication, the presented results are verified by experimentally determined data of a motor-inverter system.}, language = {en} } @inproceedings{DeNiklasMottoketal., author = {De, Sangita and Niklas, Michael and Mottok, J{\"u}rgen and Brada, Přemek}, title = {A Semantic Analysis of Interface Description Models of Heterogeneous Vehicle Application Frameworks: An Approach Towards Synergy Exploration}, series = {MODELSWARD 2019: Proceedings of the 7th International Conference on Model-Driven Engineering and Software Development, 20.02.2019 - 22.02.2019, Prague, Czech Republic}, booktitle = {MODELSWARD 2019: Proceedings of the 7th International Conference on Model-Driven Engineering and Software Development, 20.02.2019 - 22.02.2019, Prague, Czech Republic}, publisher = {SCITEPRESS}, isbn = {978-989-758-358-2}, pages = {394 -- 401}, abstract = {As the world is getting more connected, the demands of services in automotive industry are increasing with the requirements such as IoT (Internet of Things) in cars, automated driving, etc. Eventually, the automotive industry has evolved to a complex network of servi ces, where each organization depends on the other organizations, to satisfy its service requirements in different phases of the vehicle life cycle. Because of these heterogeneous and complex development environments, most of the vehicle component interface models need to be specified in various manifest ations to satisfy the semantic and syntactic requirements, specific to different application development environments or frameworks. This paperdescribes an approach to semantic analysis of components interfaces description models of heterogeneous frameworks, that are used for vehicle applications. The proposed approach intends to ensure that interface description models of different service-based vehicle frameworks can be compared, correlated and re-used based on semantic synergies, across different vehicle platforms, development environments and organizations. The approach to semantic synergy exploration could further provide the knowledge base for the increase in interoperability, overall efficiency and development of an automotive domain specific general software solutions, by facilitating coexistence of components of heterogeneous frameworks in the same high-performance ECU for future vehicle software.}, language = {en} } @inproceedings{ReindlMeierNiemetzetal., author = {Reindl, Andrea and Meier, Hans and Niemetz, Michael and Park, Sangyoung}, title = {Decentralized Battery Management System with Customized Hardware Components}, series = {IEEE 19th Student Conference on Research and Development (SCOReD), Sustainable Engineering and Technology towards Industry Revolution: 23-25 Nov. 2021, Kota Kinabalu, Malaysia}, booktitle = {IEEE 19th Student Conference on Research and Development (SCOReD), Sustainable Engineering and Technology towards Industry Revolution: 23-25 Nov. 2021, Kota Kinabalu, Malaysia}, publisher = {IEEE}, doi = {10.1109/SCOReD53546.2021.9652737}, pages = {350 -- 355}, abstract = {With an increasing number of sold electric vehicles (EVs), a large number of used batteries will be at disposal. How to deal with these resources is one of the major challenges in reducing the environmental impact of batteries throughout their entire life cycle. Heterogeneous cell parameters due to the different usage histories are a challenge for second-life use. The effort and cost of remanufacturing required to test and assemble a new battery pack is a further concern. Systems that combine battery packs/modules without full reassembly offer advantages such as cost and reusability. A decentralized battery management system (DBMS) provides a suitable architecture for such systems involving different types of batteries. In this paper, an architecture for a decentralized, battery state-dependent control is shown. The proposed DBMS supports various types of batteries, is scalable and flexibly adaptable for a wide range of applications. Despite the significant advantages, there are increased requirements to meet for the hardware implementation and the applied control strategies. Therefore, the necessary hardware components and their requirements are described and the hardware implementations are provided.}, language = {en} } @inproceedings{HopkinsHopfenspergerMellor, author = {Hopkins, Andrew and Hopfensperger, Bernhard and Mellor, Phil}, title = {DC-link Capacitor Reduction in Low Voltage and High Power Integrated Modular Motor Drives}, series = {2019 IEEE Energy Conversion Congress and Exposition (ECCE), 29 Sept.-3 Oct. 2019, Baltimore, MD, USA}, booktitle = {2019 IEEE Energy Conversion Congress and Exposition (ECCE), 29 Sept.-3 Oct. 2019, Baltimore, MD, USA}, doi = {10.1109/ECCE.2019.8913213}, pages = {3208 -- 3214}, abstract = {The development of 48V high power (>15 kW) automotive propulsion drives demands close integration of the power electronics and the electrical machine. Due to the large operating currents distributed multi-phase topologies are needed and physically separating the power converter from the e-machine would involve heavy cabling and costly connections. The volume and cost of the filter capacitor represents a major challenge in closely integrated high power integrated modular motor drives and techniques are needed to minimize this. The DC-link capacitor requires a large ripple current handling capability and cost, size and reliability limitations result in suitable candidate technologies being those with low volumetric energy densities. Use of interleaved multi three-phase machines are attractive due to the associated capacitor ripple current reduction. Discontinuous modulation schemes may also be employed as a technique for reducing the current ripple. In this paper techniques for capacitor ripple reduction are assessed through simulation and compared.}, language = {en} } @article{SykoraHolickyJungetal., author = {S{\´y}kora, Miroslav and Holicky, Milan and Jung, Karel and Diamantidis, Dimitris}, title = {Human safety criteria for risk-based structural design}, series = {International Journal of Safety and Security Engineering}, volume = {8}, journal = {International Journal of Safety and Security Engineering}, number = {2}, publisher = {WIT Press}, doi = {10.2495/SAFE-V8-N2-287-298}, pages = {287 -- 298}, abstract = {Risk and reliability criteria are well established in many industrial sectors such as the offshore, chemi- cal or nuclear industries. Comparative risk thresholds have been specified to allow a responsible organization or regulator to identify activities, which impose an acceptable level of risk concerning the participating individuals, or society as a whole. The scope of this contribution is to present target reliability criteria based on acceptable human safety levels. Application of theoretical principles is illustrated by examples of railway engineering structures. Initially it is shown how civil engineering structures for which human safety criteria play a role are classified according to Eurocodes. Examples include bridges, tunnels or station buildings. The general concepts for risk acceptance are then briefly reviewed, particularly in their relation to the target reliability criteria. The distinction between the two types of criteria is made: group risk and the acceptance criterion based on the Life Quality Index LQI approach introduced by ISO 2394:2015. The differences between the criteria for new and existing structures are discussed. The application is illustrated by an example of a bridge crossing an important railway line. It appears that while benefits and costs of a private stakeholder or public authority are reflected by economic optimisation, the society should define the limits for human safety to achieve uniform risks for various daily-life activities and across different industrial sectors. Keywords: group risk, human safety, individual risk, Life Quality Index, railway, risk acceptance, structure, target reliability}, language = {en} } @inproceedings{DiamantidisSykoraBertacca, author = {Diamantidis, Dimitris and S{\´y}kora, Miroslav and Bertacca, Elena}, title = {Obsolescence Rate: Framework, Analysis and Influence on Risk Acceptance Criteria}, series = {6th International Symposium on Life-Cycle Civil Engineering (IALCCE), Ghent, Belgium}, booktitle = {6th International Symposium on Life-Cycle Civil Engineering (IALCCE), Ghent, Belgium}, abstract = {Buildings are major long lasting assets of the society and business enterprises and form a significant part of infrastructure management. They require continual maintenance and in many cases they can become inap-propriate for their original purpose due to obsolescence and are demolished. The present contribution ex-plores the obsolescence of buildings and in particular the definitions of obsolescence, the related influenc-ing factors and the associated uncertainties. Thereby definitions of the obsolescence rate based on the physi-cal and useful (service) life are clarified. The experienced useful life of buildings in Finland, Germany and North America is statistically analysed, utilizing available databases, and comparisons with the design (minimum) working life specified in standards are made. The probability of not exceeding the required min-imum service life is evaluated and discussed. Whereas many factors affecting the obsolescence rate are be-yond the control of civil engineers, particular attention needs to be paid to cases where the service life of the structure is determined by physical aspects related to deterioration. These cases are identified and recom-mendations to improve structural design are offered. The service life and the related renewal rate is influ-encing the risk acceptance criteria as given in ISO 2394. Such criteria are derived on the basis of economic optimization and the LQI marginal safety costs principle. A statistical model for the renewal rate is obtained and its influence on the target reliability is investigated for a representative failure limit state. The influence of the obsolescence rate is quantified and critically disputed.}, language = {en} } @inproceedings{Briem, author = {Briem, Ulrich}, title = {Neue Methode zur Bestimmung der Biegesteifigkeit von Drahtseilen}, series = {Der Kran - Leistungssteigerung, Leichtbau und Automatisierung : 27. Internationale Kranfachtagung 2019 : Begleitband zur Kranfachtagung am 07. M{\"a}rz 2019 in Bochum}, booktitle = {Der Kran - Leistungssteigerung, Leichtbau und Automatisierung : 27. Internationale Kranfachtagung 2019 : Begleitband zur Kranfachtagung am 07. M{\"a}rz 2019 in Bochum}, editor = {Scholten, Jan}, publisher = {Selbstverlag der Ruhr-Universit{\"a}t Bochum}, address = {Bochum}, isbn = {3-89194-226-5}, pages = {103 -- 112}, language = {de} } @inproceedings{CarrilloLiSchorrKaufholdetal., author = {Carrillo Li, Enrique Roberto and Schorr, Philipp and Kaufhold, Tobias and Rodr{\´i}guez Hern{\´a}ndez, Jorge Antonio and Zentner, Lena and Zimmermann, Klaus and B{\"o}hm, Valter}, title = {Kinematic analysis of the rolling locomotion of mobile robots based on tensegrity structures with spatially curved compressed components}, series = {Applicable Solutions in Non-Linear Dynamical Systems; 15th International Conference "Dynamical Systems - Theory and Applications" (DSTA 2019, 2-5 December, 2019, Lodz, Poland}, booktitle = {Applicable Solutions in Non-Linear Dynamical Systems; 15th International Conference "Dynamical Systems - Theory and Applications" (DSTA 2019, 2-5 December, 2019, Lodz, Poland}, editor = {Awrejcewicz, Jan and Ka{\'{z}}mierczak, Markek and Olejnik, Paweł}, publisher = {Wydawnictwo Politechniki Ł{\´o}dzkiej}, address = {Ł{\´o}d{\'{z}}, Polen}, isbn = {978-83-66287-30-3}, pages = {335 -- 344}, abstract = {In this work, a tensegrity structure with spatially curved members is applied as rolling locomotion system. The actuation of the structure allows a variation of the originally cylindrical shape to a conical shape. Moreover, the structure is equipped with internal movable masses to control the position of the center of mass of the structure. To control the locomotion system a reliable actuation strategy is required. Therefore, the kinematics of the system considering the nonholonomic constraints are derived in this paper. Based on the resulting insight in the locomotion behavior a feasible actuation strategy is designed to control the trajectory of the system. To verify this approach kinematic analyses are evaluated numerically. The simulation data confirm the path following due to an appropriate shape change of the tensegrity structure. Thus, this system enables a two-dimensional rolling locomotion. The use of mechanically compliant tensegrity structures in mobile robots is an attractive research topic, due to the possibility to adjust their mechanical properties reversibly during locomotion. In this paper rolling locomotion of mobile robots based on simple tensegrity structures, consisting of three compressed spatially curved members connected to a continuous net of prestressed tensional members, is discussed. Planar locomotion of these robots is induced by the movement of internal masses. The movement direction can be changed by changing the robot's shape between a cylinder and a truncated cone. The paper focuses on the description of the kinematics of these systems with respect to the shape change.}, language = {en} } @inproceedings{Briem, author = {Briem, Ulrich}, title = {Lebensdauerverhalten verdichteter Seildr{\"a}hte}, series = {Ilmenauer Drahttag 2019}, booktitle = {Ilmenauer Drahttag 2019}, publisher = {ISLE Steuerungstechnik und Leistungselektronik}, address = {Ilmenau}, isbn = {978-3- 938843-96-3}, pages = {73 -- 82}, language = {de} } @article{KurzweilShamoninChamonine, author = {Kurzweil, Peter and Shamonin (Chamonine), Mikhail}, title = {State-of-Charge Monitoring by Impedance Spectroscopy during Long-Term Self-Discharge of Supercapacitors and Lithium-Ion Batteries}, series = {Batteries}, volume = {4}, journal = {Batteries}, number = {3}, publisher = {MPDI}, doi = {10.3390/batteries4030035}, pages = {1 -- 13}, abstract = {Frequency-dependent capacitance C(ω) is a rapid and reliable method for the determination of the state-of-charge (SoC) of electrochemical storage devices. The state-of-the-art of SoC monitoring using impedance spectroscopy is reviewed, and complemented by original 1.5-year long-term electrical impedance measurements of several commercially available supercapacitors. It is found that the kinetics of the self-discharge of supercapacitors comprises at least two characteristic time constants in the range of days and months. The curvature of the Nyquist curve at frequencies above 10 Hz (charge transfer resistance) depends on the available electric charge as well, but it is of little use for applications. Lithium-ion batteries demonstrate a linear correlation between voltage and capacitance as long as overcharge and deep discharge are avoided.}, language = {en} } @article{FreniFrazzicaDawoudetal., author = {Freni, Angelo and Frazzica, Andrea and Dawoud, Belal and Chmielewski, Stefanie and Calabrese, Luigi and Bonaccorsi, Lucio Maria}, title = {Adsorbent coatings for heat pumping applications: Verification of hydrothermal and mechanical stabilities}, series = {Applied Thermal Engineering}, volume = {50}, journal = {Applied Thermal Engineering}, number = {2}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2011.07.010}, pages = {1658 -- 1663}, abstract = {This paper presents novel experimental methods for verification of both hydrothermal and mechanical stabilities of adsorbent coatings. Experiments have been carried out on zeolite-based coatings over aluminum substrates, prepared by a dip-coating technique developed at CNR-ITAE. Hydrothermal aging of several adsorbent coatings is ongoing. Adsorption and structural stability of some samples under test was successfully verified after 35000 aging cycles by isobars measurement and XRD analysis. Mechanical properties of coatings have been evaluated by applying different typologies of static and dynamic mechanical stresses. Results obtained have been compared with those achieved by subjecting adsorbent coatings prepared by Mitsubishi Plastic Incorporation (MPI) to the same characterization protocol. The comparison between the two types of coating returned that MPI coatings posses similar thermal stability and better mechanical strength than CNR-ITAE coatings.}, language = {en} } @article{FrazzicaPalombaDawoudetal., author = {Frazzica, Andrea and Palomba, Valeria and Dawoud, Belal and Gull{\`i}, Giuseppe and Brancato, Vincenza and Sapienza, Alessio and Vasta, Salvatore and Freni, Angelo and Costa, Fabio and Restuccia, Giovanni}, title = {Design, realization and testing of an adsorption refrigerator based on activated carbon/ethanol working pair}, series = {Applied Energy}, volume = {174}, journal = {Applied Energy}, publisher = {Elsevier}, doi = {10.1016/j.apenergy.2016.04.080}, pages = {15 -- 24}, abstract = {In the present paper design, realization and testing of a novel small scale adsorption refrigerator prototype based on activated carbon/ethanol working pair is described. Firstly, experimental activity has been carried out for identification of the best performing activated carbon available on the market, through the evaluation of the achievable thermodynamic performance both under air conditioning and refrigeration conditions. Once identified the best performing activated carbon, the design of the adsorber was developed by experimental dynamic performance analysis, carried out by means of the Gravimetric-Large Temperature Jump (G-LTJ) apparatus available at CNR ITAE lab. Finally, the whole 0.5 kW refrigerator prototype was designed and built. First experimental results both under reference air conditioning and refrigeration cycles have been reported, to check the achievable performance. High Specific Cooling Powers (SCPs), 95 W/kg and 50 W/kg, for air conditioning and refrigeration respectively, were obtained, while the COP ranged between 0.09 and 0.11, thus showing an improvement of the current state of the art. (C) 2016 Elsevier Ltd. All rights reserved.}, language = {en} } @article{KalitaSnarskiiShamoninChamonineetal., author = {Kalita, Viktor M. and Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail and Zorinets, Denis}, title = {Effect of single-particle magnetostriction on the shear modulus of compliant magnetoactive elastomers}, series = {Physical review E}, volume = {95}, journal = {Physical review E}, number = {3}, publisher = {American Physical Society}, doi = {10.1103/PhysRevE.95.032503}, abstract = {The influence of an external magnetic field on the static shear strain and the effective shear modulus of a magnetoactive elastomer (MAE) is studied theoretically in the framework of a recently introduced approach to the single-particle magnetostriction mechanism [V. M. Kalita et al., Phys. Rev. E 93, 062503 (2016)]. The planar problem of magnetostriction in an MAE with magnetically soft inclusions in the form of a thin disk (platelet) having the magnetic anisotropy in the plane of this disk is solved analytically. An external magnetic field acts with torques on magnetic filler particles, creates mechanical stresses in the vicinity of inclusions, induces shear strain, and increases the effective shear modulus of these composite materials. It is shown that the largest effect of the magnetic field on the effective shear modulus should be expected in MAEs with soft elastomer matrices, where the shear modulus of the matrix is less than the magnetic anisotropy constant of inclusions. It is derived that the effective shear modulus is nonlinearly dependent on the external magnetic field and approaches the saturation value in magnetic fields exceeding the field of particle anisotropy. It is shown that model calculations of the effective shear modulus correspond to a phenomenological definition of effective elastic moduli and magnetoelastic coupling constants. The obtained theoretical results compare well with known experimental data. Determination of effective elastic coefficients in MAEs and their dependence on magnetic field is discussed. The concentration dependence of the effective shear modulus at higher filler concentrations has been estimated using the method of Pade approximants, which predicts that both the absolute and relative changes of the magnetic-field-dependent effective shear modulus will significantly increase with the growing concentration of filler particles.}, language = {en} } @article{BruniMeijaardRilletal., author = {Bruni, S. and Meijaard, J. P. and Rill, Georg and Schwab, A. L.}, title = {State-of-the-art and challenges of railway and road vehicle dynamics with multibody dynamics approaches}, series = {Multibody System Dynamics}, volume = {49}, journal = {Multibody System Dynamics}, number = {1}, publisher = {Springer}, doi = {10.1007/s11044-020-09735-z}, pages = {1 -- 32}, abstract = {A review of the current use of multibody dynamics methods in the analysis of the dynamics of vehicles is given. Railway vehicle dynamics as well as road vehicle dynamics are considered, where for the latter the dynamics of cars and trucks and the dynamics of single-track vehicles, in particular motorcycles and bicycles, are reviewed. Commonalities and differences are shown, and open questions and challenges are given as directions for further research in this field.}, language = {en} } @article{SchwanzerRablLodersetal., author = {Schwanzer, Peter and Rabl, Hans-Peter and Loders, S. and Seifert, P. and Himmelstoss, S. and Gaderer, Matthias}, title = {Difference in the Tailpipe Particle Number by Consideration of Sub-23-nm Particles for Different Injection Settings of a GDI Engine}, series = {Emission control science and technology}, volume = {5}, journal = {Emission control science and technology}, number = {1}, publisher = {Springer Nature}, doi = {10.1007/s40825-019-0114-1}, pages = {7 -- 22}, abstract = {The purpose of this study was to investigate the characteristic of nanoparticles under consideration of sub-23-nm particles from a 1.8-l direct injection (DI) gasoline engine under stoichiometric air/fuel conditions in the exhaust gas system. For future CO2 challenges, the usage of DI-instead of port fuel injection (PFI)-gasoline engines is unavoidable. Therefore, a state of the art particle management program-particle number (PN) system, the Horiba SPCS (2100) with an integrated CPC (condensation particle counter), was recalibrated from a 50\% cutoff (D-50\%) at 23 nm down to a cutoff at 10 nm and the PCRF (particle concentration reduction factor) for sizes smaller than 23 nm was checked. Two different modal points, out of a representative Real Driving Emission (RDE) cycle, were investigated with both calibrations, D-50\%=10 nm and D-50\%=23 nm. For these different load points, the fuel pressure (FUP) and the start of injection (SOI) were varied, to represent the difference in the structure and the ratio conc((10 nm))/conc((23 nm)) of the nanoparticle emissions. The particle characterization includes the particle number (PN), the particle size distribution (PSD), and the particle mass (PM). The particle number was measured with Horiba SPCS (2100). The particle size distribution was analyzed with a Grimm differential mobility analyzer (DMA) in combination with a Faraday cup electrometer (FCE). Micro Soot and Pegasor were used to determine the PM, and an optical characterization was done with a 120-kV Phillips CM12 transmission electron microscope (TEM). The position of all particle measurement systems was downstream the three-way catalyst (TWC). The results of this investigation showed that a higher injection pressure decreases the PN (without consideration of sub-23-nm particles) in general. The ratio conc((10 nm))/conc((23 nm)) was therefore higher, because smaller particles, especially ash particles, were less reduced from the FUP. This means higher FUP tends to a higher ratio. For the SOI, the main reasons of the ratio differences were explained by an encroachment between the injection jet and the piston, the valve and the wall.}, language = {en} } @article{SchwanzerSchillingerMieslingeretal., author = {Schwanzer, Peter and Schillinger, Maximilian and Mieslinger, Johann and Walter, Stefanie and Hagen, Gunter and Maerkl, Susanne and Haft, Gerhard and Dietrich, Markus and Moos, Ralf and Gaderer, Matthias and Rabl, Hans-Peter}, title = {A Synthetic Ash-Loading Method for Gasoline Particulate Filters with Active Oil Injection}, series = {SAR International Journal of Engines}, volume = {14}, journal = {SAR International Journal of Engines}, number = {4}, publisher = {SAE International}, issn = {1946-3936}, doi = {10.4271/03-14-04-0029}, pages = {493 -- 506}, abstract = {To reduce particulate emissions, the use of particulate filters in diesel engines is meanwhile state of the art, while the integration of such systems in gasoline engines is now also necessary in order to comply with today's regulations. Over its lifetime, a gasoline particulate filter (GPF) collects ash components of fuel, lubrication oil, and materials originating from the catalytic coating and from engine abrasion. In the development and application process, synthetic ashing from GPFs is challenging. The ash of the lubrication oil can be increased in various ways, like oil-doped fuel, a separate oil burner, or changes in the piston-cylinder system of the engine. However, these methods show major disadvantages. For this reason, an improved approach is presented in this study, which allows a quick response to changes in combustion (e.g., engine knocking) and producing ash, which is more realistic due to its primary particle size and the density of ash plugs, in a shorter time. Therefore, an approach to accelerate ash loading by active oil injection using a multi-point injection (MPI) system is introduced. With the help of this methodology, an ashing capacity of 1.21 g/h is implemented, which is a high rate compared to other investigations. The primary particle size (evaluated by means of a transmission electron microscope), is in the same size range as those detected at the full-load curve during regular operation. A computer tomographic (CT) analysis of the incinerated particulate filter also shows that a very high density of ash plugs can be realized, which has also been found in the literature for real applications. In addition, with the help of a mass spectrometer (MS) and an intermediate weighing of the particulate filter, the current ash loading of the GPF could be determined with an accuracy of 1\%.}, language = {en} } @article{SchorrZentnerZimmermannetal., author = {Schorr, Philipp and Zentner, Lena and Zimmermann, Klaus and B{\"o}hm, Valter}, title = {Jumping locomotion system based on a multistable tensegrity structure}, series = {Mechanical systems and signal processing}, journal = {Mechanical systems and signal processing}, number = {152}, publisher = {Elsevier}, doi = {10.1016/j.ymssp.2020.107384}, abstract = {All known locomotion principles are limited respective to environmental conditions. Often, the occurrence of obstacles or gaps means the break-off for the operating motion systems. For such circumstances, a controllable jumping locomotion is required to cross these barriers. However, this locomotion demands sophisticated requirements to the actuation. The abrupt actuation is commonly realized by high dynamic actuators or complex mechanisms. In this work, a simple solution utilizing the multistability of a compliant tensegrity structure is described. Therefore, a two-dimensional tensegrity structure featuring four stable equilibria is considered. Based on bifurcation analyses a feasible actuation to control the current equilibrium configuration is derived. Changing between selected equilibrium states enables a great difference in potential energy, which yields a jumping motion of the structure. Based on numerical simulations a suitable actuation strategy is chosen to overcome obstacle and steps by jumping forward or backward, respectively. The theoretical approach is examined experimentally with a prototype of the multistable tensegrity structure. (c) 2020 Elsevier Ltd. All rights reserved. All known locomotion principles are limited respective to environmental conditions. Often, the occurrence of obstacles or gaps means the break-off for the operating motion systems. For such circumstances, a controllable jumping locomotion is required to cross these barriers. However, this locomotion demands sophisticated requirements to the actuation. The abrupt actuation is commonly realized by high dynamic actuators or complex mechanisms. In this work, a simple solution utilizing the multistability of a compliant tensegrity structure is described. Therefore, a two-dimensional tensegrity structure featuring four stable equilibria is considered. Based on bifurcation analyses a feasible actuation to control the current equilibrium configuration is derived. Changing between selected equilibrium states enables a great difference in potential energy, which yields a jumping motion of the structure. Based on numerical simulations a suitable actuation strategy is chosen to overcome obstacle and steps by jumping forward or backward, respectively. The theoretical approach is examined experimentally with a prototype of the multistable tensegrity structure.}, language = {en} } @article{SindersbergerPremMonkman, author = {Sindersberger, Dirk and Prem, Nina and Monkman, Gareth J.}, title = {Self-assembling structure formation in low-density magnetoactive polymers}, series = {Journal of Applied Polymer Science}, volume = {137}, journal = {Journal of Applied Polymer Science}, number = {3}, publisher = {Wiley}, doi = {10.1002/app.48291}, abstract = {The formation of microstructures in magnetoactive polymers (MAPs) is a recently discovered phenomenon found only with very low filler particle concentrations (less than 3 wt \%). Due to the degassing process, filler particles collect around an ascending bubble, which dissolves at a certain point leaving particulate rings within the matrix. The formation of toroidal microstructures commences as filler concentration approaches 1 wt \%. The development of coherent parallel aligned rings with a compact order continues as particle concentrations increase toward 2 wt \%. Between 2 and 3 wt \% capillary doublets develop, while mass percentages higher than 3\% result in increasing entropy as the random order of particle agglomeration found in higher concentration MAP dominates. Self-structured samples of different filler material and concentrations between 1 and 3 wt \% have been investigated using X-ray tomography, where the emerging structures can be observed and visualized. The ring structures resulting from this research represent microinductivities which can be fabricated in a targeted manner, thus enabling new applications in the high-frequency radio field. Furthermore, these anisotropic, but well-organized, structures have magnetic field-dependent implications for optical, thermal, acoustic, and medical applications.}, language = {en} } @article{SchulzSchwarz, author = {Schulz, Carsten and Schwarz, Colin}, title = {Drivetrain fatigue strength characteristics of model-predictive control for wind turbines}, series = {Wind Energy}, volume = {23}, journal = {Wind Energy}, number = {12}, publisher = {Wiley}, doi = {10.1002/we.2520}, pages = {2137 -- 2149}, abstract = {Wind turbines play a crucial role in the revolution towards renewable resources. They need to be economically competitive to be sustainable. This still requires to lower the cost of energy (COE). To this end, nonlinear model predictive control (NMPC) is used within this paper. As known from literature, NMPC significantly improves the energy extracting performance as well as the mitigation of tower loads of wind turbines. As it is shown in this paper, the drivetrain fatigue strength drops disproportionally in parallel, which either increases the demands on the turbine design or decreases the lifetime of drivetrain components. Without additional boundary conditions to the underlying optimal control problems (OCPs), the application of energy-maximizing NMPC might so even raise the COE. Only penalizing axial torque oscillations by quadratic terms decreases energy-extracting performance below the level of classical wind turbine controllers. This makes more sophisticated conditions necessary. In this paper, the increase of the drivetrain damage by NMPC is analyzed, and appropriate boundary conditions are derived, to balance the two contradicting objectives of energy maximization and drivetrain load mitigation. An NMPC approach based on indirect methods is used, to obtain a solution of the OCPs very efficiently. It applies the Hamilton equations and Pontryagin's maximum principle. Its accuracy and efficiency to solve OCPs was presented over the last decades.}, language = {en} } @inproceedings{BogomolovKralHaumeretal., author = {Bogomolov, Maxim and Kral, Christian and Haumer, Anton and Lomonova, Elena}, title = {Modeling of permanent magnet synchronous machine with fractional slot windings}, series = {Proceedings IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society ; Ecole de Technologie Superieure de Montreal, Universite du Quebec Montreal, Canada 25 - 28 October, 2012}, booktitle = {Proceedings IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society ; Ecole de Technologie Superieure de Montreal, Universite du Quebec Montreal, Canada 25 - 28 October, 2012}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4673-2421-2}, issn = {1553-572X}, doi = {10.1109/IECON.2012.6388912}, pages = {1894 -- 1899}, abstract = {This paper focuses on simulation of permanent magnet synchronous machine (PMSM) with fractional-slot windings (FSW) in Modelica. Modeling of the electrical machines with object-oriented approach is shortly described, and a new Modelica library for simulation of electrical machines is introduced. The results of simulation of PMSMs with fractional slot windings are presented and explained. Special attention is paid to the higher harmonics and subharmonics produced by the winding and their influence on machine operation.}, language = {en} } @inproceedings{ReindlSingerMeieretal., author = {Reindl, Andrea and Singer, Thomas and Meier, Hans and Niemetz, Michael and Park, Sangyoung}, title = {Framework to Test DC-DC Converters Developed for a Decentralized Battery Management System}, series = {2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021, Pilsen, Czech Republic}, booktitle = {2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021, Pilsen, Czech Republic}, publisher = {IEEE}, doi = {10.23919/AE51540.2021.9542882}, pages = {1 -- 6}, abstract = {DC- DC converters control the power flow and thus the power distribution between the components on different voltage levels. They are essential for (dis)charging batteries and influence the safety and stability of the entire battery management system (BMS). Therefore, testing the functionality and the reliability of DC-DC converters is crucial. This is especially true for decentralized battery management systems (DBMS), where multiple nodes communicate to collectively control the system. The used DC-DC converters are modified to parameterize them during operation via microcontroller interfaces. Integrating the communication into the control loop requires an analysis of the control behavior due to additional delays. Therefore, this paper proposes a framework to test DC-DC converters considering the control and communication perspectives. The response time, the control accuracy and stability of these DC-DC converters, e.g., under continuous and abrupt load changes, are measured in automated tests. The dedicated software framework simulates the DBMS and stimulates the hardware components (e.g. electronic loads, data acquisition) via respective interfaces (CAN, RS232). This allows the test of various DC-DC converters with flexibly adaptable load and power generation profiles. An initial application validates the test framework by verifying the aforementioned aspects and thus the applicability of a DC-DC converter within the DBMS.}, language = {en} } @inproceedings{BrkicCeranElmoghazyetal., author = {Brkic, Jovan and Ceran, Muaz and Elmoghazy, Mohamed and Kavlak, Ramazan and Haumer, Anton and Kral, Christian}, title = {Open Source PhotoVoltaics Library for Systemic Investigations}, series = {Proceedings of the 13th International Modelica Conference, March 4-6, 2019, Regensburg, Germany}, booktitle = {Proceedings of the 13th International Modelica Conference, March 4-6, 2019, Regensburg, Germany}, publisher = {Link{\"o}ing University Electronic Press}, doi = {10.3384/ecp1915741}, pages = {41 -- 50}, abstract = {For the planning of photovoltaic power plants standard software tools are used. Most of these software tools use statistical solar data to determine the overall energy harvest of a photovoltaic plant over one year. The calculations rely on stationary location and ideal boundary conditions, e.g., constant ambient temperature. Even though, for example, shadowing may be considered by standard software, the investigation of untypical configurations and problems cannot be performed by such software, as most configurations cannot be changed by the user. The presented PhotoVoltaics library was developed with the intention to provide a flexible framework for standard and non-standard problems. Particularly, the PhotoVoltaics library can be coupled with other Modelica libraries to perform systemic investigations. An application library, PhotoVoltaics_TGM, is provided as add-on, where measured data of two photovoltaic pants of the TGM in Vienna can be compared with simulation results. This add-on library serves as validation of the PhotoVoltaics library.}, language = {en} } @inproceedings{ScharfenbergElisHofmann, author = {Scharfenberg, Georg and Elis, Ludek and Hofmann, Gerhard}, title = {New Design Methodology - Using VHDL-AMS Models to Consider Aging Effects in Automotive Mechatronic Circuits for Safety Relevant Functions}, series = {2019 International Conference on Applied Electronics (AE), 10-11 Sept. 2019, Pilsen, Czech Republic}, booktitle = {2019 International Conference on Applied Electronics (AE), 10-11 Sept. 2019, Pilsen, Czech Republic}, doi = {10.23919/AE.2019.8867034}, pages = {1 -- 5}, abstract = {In this paper a design method for mechatronic functions in an early design phase under consideration of the requirements of functional safety is proposed [14]. The goal of the method is to discover threats for the safety goals and to prove or optimize the diagnostic mechanisms. At the current design process a lifetime endurance test is performed in a late project phase. In order to avoid unexpected late design changes the method should be applied in an early design phase. The method is an additional way to avoid design failures for E/E functions with special focus on aging in the field of functional safety applications. The method is developed out of three standards VDI 2221 methodology for development and construction of technical systems and products [1]), VDI 2206 design methodology for mechatronic systems [2] and the ISO 26262 road vehicles - Functional Safety [3] by using the V-Model. Furthermore, a core element of the design method is simulating aging effects by applying VHDL - AMS. To demonstrate the design methodology a sensor out of the EGAS function is chosen as a safety relevant automotive system. The limitation is the availability of aging data for electrical components.}, language = {en} } @article{BraunDurnerRabletal., author = {Braun, Peter and Durner, Bernhard and Rabl, Hans-Peter and Matysik, Frank-Michael}, title = {Investigations on the decomposition of AdBlue urea in the liquid phase at low temperatures by an electrochemically induced pH shift}, series = {Monatshefte f{\"u}r Chemie}, volume = {150}, journal = {Monatshefte f{\"u}r Chemie}, number = {9}, publisher = {Springer}, doi = {10.1007/s00706-019-02406-6}, pages = {1633 -- 1641}, abstract = {Ammonia-based selective catalytic reduction (SCR) systems are the most widely used technology for reduction of nitrogen oxide emissions from lean-burn engines such as diesel engines. However, at low exhaust temperatures, the SCR process is limited by difficulties in the decomposition of the ammonia precursor urea, which is carried on-board using an aqueous solution "AdBlue". In this study, the decomposition of AdBlue urea induced by electrical current and the resulting associated pH shifts were investigated in a divided cell configuration in the liquid phase. The decomposition was found to be favored in both electrochemical compartments, anodic and cathodic, at temperatures of 60-80 degrees C compared to a reference without electrochemical treatment. In addition to the determination of ammonia contents using an ammonia sensor, IC/HPLC analyses were carried out for each sample. Different side products such as biuret, nitrate, cyanuric acid, ammelide, and others were formed. In the anodic compartment, nitrate formation could be observed due to oxidation of ammonia at the electrode surface. [GRAPHICS] .}, language = {en} } @article{BraunRablMatysik, author = {Braun, Peter and Rabl, Hans-Peter and Matysik, Frank-Michael}, title = {Investigations on the Liquid-Phase Decomposition of AdBlue Urea for the Selective Catalytic Reduction Process}, series = {Chemie Ingenieur Technik}, volume = {91}, journal = {Chemie Ingenieur Technik}, number = {7}, publisher = {Wiley}, doi = {10.1002/cite.201800055}, pages = {961 -- 968}, abstract = {Difficulties in decomposing AdBlue to ammonia limit the applicability of selective catalytic reduction systems at low exhaust temperatures. Investigations on the decomposition of AdBlue in the liquid phase under elevated pressure at temperatures up to 165 degrees C were carried out. Besides effects of inorganic catalysts, the impact of pH on urea decomposition was examined. After dissolution in aqueous phase, the compounds ZnO, WO3, and MoO3 were found to be effective in liquid-phase AdBlue decomposition. However, the efficiency was dropping significantly over few hours. Decomposition of AdBlue urea was also found to be favored for alkaline and acidic conditions.}, language = {en} } @misc{Weiss, author = {Weiss, Nils}, title = {Vulnerabilities of OBD2 Dongles}, series = {RCAR Annual Conference, 2018, Munich, Germany}, journal = {RCAR Annual Conference, 2018, Munich, Germany}, language = {en} } @misc{Weiss, author = {Weiss, Nils}, title = {Vulnerabilities of Connected Cars and beyond}, series = {Applied Research Colloquium, 2019, Universit{\`a} Padua, Italy}, journal = {Applied Research Colloquium, 2019, Universit{\`a} Padua, Italy}, language = {en} } @article{PalombaNowakDawoudetal., author = {Palomba, Valeria and Nowak, Sebastian and Dawoud, Belal and Frazzica, Andrea}, title = {Dynamic modelling of Adsorption systems: a comprehensive calibrated dataset for heat pump and storage applications}, series = {Journal of energy storage}, volume = {33}, journal = {Journal of energy storage}, publisher = {Elsevier}, doi = {10.1016/j.est.2020.102148}, abstract = {The growing efforts for the development of clean and efficient energy systems require the use of a multi-disciplinary approach and the integration of multiple generation appliances. Among the fields that can be considered enabling technologies, adsorption systems for air conditioning and thermal energy storages, are constantly increasing their maturity. However, for a proper design and integration of such systems, there is the need for a simulation framework that is reliable and computationally convenient. In the present paper, the implementation of a dynamic model for adsorption systems is presented, which includes different components (adsorber, phase changer, sorption materials) and is structured as a library. Modelica language and the commercial software Dymola (R) are used for the analysis. Data for different heat exchangers and working pairs are calibrated using experimental results and the calibrated model is subsequently used for the design of an adsorber based on a plate heat exchanger for thermal energy storage applications. The results proved that the model is fast and can reproduce experimental results with good accuracy, thus being a useful tool for the design and optimization of the different components of sorption systems.}, language = {en} } @article{RillBauerKirchbeck, author = {Rill, Georg and Bauer, Florian and Kirchbeck, Mathias}, title = {VTT - a virtual test truck for modern simulation tasks}, series = {Vehicle system dynamics}, volume = {59}, journal = {Vehicle system dynamics}, number = {4}, publisher = {Taylor\&Francis}, doi = {10.1080/00423114.2019.1705356}, pages = {635 -- 656}, abstract = {The development of new technologies like advanced driver assistance systems or automated driving requires a flexible simulation environment of sufficient complexity. In general this flexibility is not provided by commercial software packages. This paper presents a three-dimensional and nonlinear hand-made model for heavy commercial vehicles including tractor and trailer as well as tractor and semitrailer combinations that can be used in different simulation environments, as well as in real-time applications. As typical for trucks, the torsional flexibility of the frame and a suspended driver's cabin are taken into account. The design kinematics makes it possible to handle different and quite complex axle suspensions very efficiently. Appropriate force elements are used to model various couplings between tractor and trailer or tractor and semitrailer, respectively. The virtual test truck environment (VTT) coded in ANSI C is extremely portable and can easily be embedded in commercial simulation packages like MATLAB/Simulink. It includes the TMeasy tyre model and offers flexible interfaces to third-party software tools.}, language = {en} } @article{Rill, author = {Rill, Georg}, title = {Sophisticated but quite simple contact calculation for handling tire models}, series = {Multibody system dynamics}, volume = {45}, journal = {Multibody system dynamics}, number = {2}, publisher = {Springer Nature}, organization = {SPRINGER}, doi = {10.1007/s11044-018-9629-4}, pages = {131 -- 153}, abstract = {Handling tire models like Pacejka (Tire and Vehicle Dynamics, 3rd edn., Elsevier, Amsterdam, 2012) or TMeasy (Rill in Proc. of the XV Int. Symp. on Dynamic Problems of Mechanics, Buzios, RJ, Brazil, 2013) consider the contact patch as one coherent plane. As a consequence, the irregularities of a rough road profile must be approximated by an appropriate local road plane that serves as an effective road plane in order to calculate the geometric contact point and the corresponding contact velocities. The Pacejka/SWIFT tire model employs a road enveloping model that generates the effective height and slope by elliptical cams. TMeasy just uses four representative road points for that purpose. In addition, TMeasy replaces the geometric contact point by the static contact point and shifts it finally to the dynamic contact point that represents the point where the contact forces are applied. In doing so, a rather sophisticated but still simple contact calculation is possible. Simulations obtained with a virtual tire test rig and fully nonlinear three-dimensional multibody system models of a motor-scooter and a passenger car demonstrate the potential of this contact approach.}, language = {en} } @techreport{ZacherlWopperMieslingeretal., author = {Zacherl, Florian and Wopper, Christoph and Mieslinger, Johann and Peis, Michael and Rabl, Hans-Peter}, title = {Schlussbericht zum Verbundvorhaben NAMOSYN: Nachhaltige Mobilit{\"a}t durch synthetische Kraftstoffe}, address = {Regensburg}, pages = {156}, abstract = {Im Labor f{\"u}r Verbrennungsmotoren und Abgasnachbehandlung der OTH-Regensburg sollten im Zuge des NAMOSYN-Projektes zwei Vertreter klimaneutraler Kraftstoffe an verschiedenen Systempr{\"u}fst{\"a}nden (Motor-, Einspritzpr{\"u}fstand, optisch zug{\"a}ngliche Einspritzkammer, …) und mit Hilfe von Simulationsmethoden f{\"u}r den Einsatz in bestehenden Verbrennungsmotoren untersucht werden. Synthetische Kraftstoffe aus der Gruppe der Oxymethylenether (OME) stellen eine CO2-neutrale Alternative zu fossilem Dieselkraftstoff dar. F{\"u}r Ottomotoren wurde untersucht, ob der synthetische Kraftstoff DMC/MeFo (Dimethylcarbonat \& Methylformiat) einen Ersatz f{\"u}r Ottokraftstoff darstellen kann, bzw. eine Drop-In-F{\"a}higkeit gegeben ist. Die OTH Regensburg bearbeitete 2 unabh{\"a}ngige Teilvorhaben zur motorischen Testung von synthetischen Kraftstoffen: „FC 1A: Motorische Testung von OME" und „FC 2: Untersuchung von C1-Oxygenaten f{\"u}r Ottomotoren". Die Projektlaufzeit betrug 3,5 Jahre, inkl. kostenneutraler Verl{\"a}ngerung um 6 Monate aufgrund der Corona-Pandemie. Im FC1A "AP2-Nachr{\"u}stung Dieselmotoren" der OTH Regensburg lag der Fokus auf der Erforschung der Potentiale und der Umr{\"u}stung eines Einzylinder-Dieselmotors mit Pumpe-Leitung-D{\"u}se-(PLD)-Einspritzsystem des Projektpartners Motorenfabrik Hatz GmbH und Co. KG f{\"u}r OME-Betrieb. Im AP2.1 wurden umfangreiche Daten gesammelt und Simulationsmodelle des Motors und PLD-Einspritzsystems erstellt und mit Dieselkraftstoff und OME validiert. Nachfolgend wurden Parameterstudien zur Geometrie des Einspritzsystems und der physikalischen Eigenschaften von OME durchgef{\"u}hrt. In AP2.2 und AP2.3 wurden umfangreiche Untersuchungen an einem Motor- und Einspritzsystempr{\"u}fstand mit Diesel und OME durchgef{\"u}hrt und der Steuerger{\"a}tedatensatz f{\"u}r den OME-Betrieb optimiert. Die Ergebnisse zeigen, dass die Umstellung des Kraftstoffs auf OME, insbesondere bei einfachen Motoren mit rudiment{\"a}rer Einspritztechnik und ohne Mittel zur NOx-Reduzierung (keine AGR oder SCR), ein enormes Potenzial zur Steigerung des Wirkungsgrads bei gleichzeitiger Reduzierung aller regulierten Schadstoffe (NOx, 𝑃N, 𝑃M, CO und 𝑉OC) er{\"o}ffnet. Die Ergebnisse und generierten Simulationsmodelle unterst{\"u}tzen eine schnelle Serienentwicklung und Einf{\"u}hrung von OME-Umr{\"u}stl{\"o}sungen. In FC 2 werden die vielversprechenden Kraftstoffe Methylformiat (MeFo) und Dimethylcarbonat (DMC) motorisch getestet. Untersuchungen am Kraftstoffsystem und wichtigen Komponenten dienen als Grundlage f{\"u}r das AP3. Im AP3 wird die Machbarkeit der DMC/MeFo-Verbrennung am Vollmotor demonstriert und die erwarteten Emissionsvorteile gegen{\"u}ber herk{\"o}mmlichen Ottokraftstoffen gezeigt. Abweichend von der urspr{\"u}nglichen Planung werden an der OTH Regensburg Kraftstoffblends aus Benzin und MeFo untersucht, um den Einsatzbereich des Kraftstoffs zu erweitern. In AP5 werden potentielle Mischungsverh{\"a}ltnisse analysiert und die Eigenschaften der ausgew{\"a}hlten Kraftstoffmischungen an einem Einspritzratenpr{\"u}fstand, an der Einspritzkammer und am Vollmotor untersucht. Es werden Einspritzverhalten, Gemischaufbereitung und Abgasemissionen bewertet. Zudem wird eine Kraftstoffmischanlage entwickelt und ein optischer Zugang am Vollmotor erm{\"o}glicht. Eine {\"O}lverd{\"u}nnungsmesstechnik wird eingesetzt, um den Kraftstoffeintrag ins Motor{\"o}l zu untersuchen}, language = {de} } @inproceedings{SchubertLeeOoi, author = {Schubert, Martin J. W. and Lee, Wai-Kong and Ooi, Boon Yaik}, title = {Quantization and Sampling Effects in Fast Digitally Controlled Switch-Mode DC/DC Buck Converters}, series = {2021 IEEE Industrial Electronics and Applications Conference (IEACon): 22.11.2021 - 23.11.2021, Penang, Malaysia}, booktitle = {2021 IEEE Industrial Electronics and Applications Conference (IEACon): 22.11.2021 - 23.11.2021, Penang, Malaysia}, publisher = {IEEE}, isbn = {978-1-7281-9253-6}, doi = {10.1109/IEACon51066.2021.9654272}, pages = {56 -- 61}, abstract = {Software-defined control of DC/DC switch mode power converters features unequaled flexibility compared to analog control. For fast switching converters as recently used for low power applications, digital control may cause steady-state oscillations known as limit cycles. This effect based on a quantized duty cycle is compared to other aberrations such as output ripple voltage, which is inherent to any pulse-width modulator. A distinction is made between DC and AC errors. The latter are divided into synchronous and asynchronous output voltage disturbances. Synchronous AC errors are composed of the switching frequency and its harmonics.}, language = {en} } @inproceedings{ReindlMeierNiemetz, author = {Reindl, Andrea and Meier, Hans and Niemetz, Michael}, title = {Software Framework for the Simulation of a Decentralized Battery Management System Consisting of Intelligent Battery Cells}, series = {2019 IEEE Student Conference on Research and Development (SCOReD), 15-17 Oct. 2019, Bandar Seri Iskandar, Malaysia}, booktitle = {2019 IEEE Student Conference on Research and Development (SCOReD), 15-17 Oct. 2019, Bandar Seri Iskandar, Malaysia}, doi = {10.1109/SCORED.2019.8896284}, pages = {75 -- 80}, abstract = {Conventional battery management systems typically adopt hierarchical master-slave architectures. With regard to an uninterruptible power supply, the most significant disadvantage of central structures is the dependency of the errorfree function of the superior master board. The decentralized battery management system presented in this paper, consisting of consumers, generators and intelligent battery cells, is controlled without any central coordination authority. For this purpose, an intelligent control algorithm and a leader election algorithm are implemented on the microcontrollers of the battery cells. To test different control and election strategies, a software framework is presented for the complete simulation of the decentralized battery management system consisting of equal participants.}, language = {en} } @inproceedings{AlexanderHaumer, author = {Alexander, Grimm and Haumer, Anton}, title = {Parametrization Of A Simplified Physical Battery Model}, series = {Proceedings of the 13th International Modelica Conference, March 4-6, 2019, Regensburg, Germany}, booktitle = {Proceedings of the 13th International Modelica Conference, March 4-6, 2019, Regensburg, Germany}, publisher = {Link{\"o}ing University Electronic Press}, doi = {10.3384/ecp19157215}, pages = {215 -- 220}, abstract = {The importance of batteries is increasing, especially in the field of the high power requirement systems like electric driven vehicles. Mobile energy storage makes it possible to accelerate with incredible torque, without any accruing air pollution. Due to the high costs of real components, it is of great use to simulate battery driven systems before building them. Transient processes within a cell are highly dependent on the operating point of the complete system, which makes it difficult to create equations and model arameterizations. This paper shows which data is important for cell modeling and how to parameterize simplified physical cell models.}, language = {en} } @article{Dawoud, author = {Dawoud, Belal}, title = {Water vapor adsorption kinetics on small and full scale zeolite coated adsorbers; A comparison}, series = {Applied thermal engineering}, volume = {50}, journal = {Applied thermal engineering}, number = {2}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2011.07.013}, pages = {1645 -- 1651}, abstract = {A possibility to enhance both heat and mass transfer characteristics of an adsorber heat exchanger is to apply the adsorbent directly to its surface in form of a consolidated layer. As the majority of the available publications on the effect of both coating technology and adsorbent layer thickness on the adsorption kinetics deals with small scale adsorbent samples, the results obtained can only represent the best case design of an adsorber heat exchanger. This article presents, therefore, a comparison between the adsorption kinetics of water vapour on small as well as two different full scale coated adsorber heat exchanger types with AQSOA-Z02 layers of Mitsubishi Plastics Incorporation under quasi isobaric conditions of adsorption heat pumps. The small scale coated samples have a zeolite dry mass of 200 mg and layer thicknesses of 200, 300 and 500 μm while the full scale adsorbers have a coated zeolite mass between 1.5 and 2.5 kg and layer thicknesses of 150, 200, 300, 400 and 500 μm. In the investigated adsorption heat pump module, up to 52.7 and 57.3\% of the equilibrium differential water loading measured with the small scale coated substrates have been obtained after an adsorption-evaporation times of 300 and 600 s, respectively.}, language = {en} } @article{FuhrmannMottok, author = {Fuhrmann, Thomas and Mottok, J{\"u}rgen}, title = {Ethical, intercultural and professional impulses integrated into a transmission systems lecture}, series = {2017 IEEE Global Engineering Education Conference (EDUCON), 25-28 April 2017, Athens, Greece}, journal = {2017 IEEE Global Engineering Education Conference (EDUCON), 25-28 April 2017, Athens, Greece}, publisher = {IEEE}, doi = {10.1109/EDUCON.2017.7942829}, pages = {92 -- 95}, abstract = {In the sixth semester of the bachelor study course "Electrical Engineering and Information Technology", a lecture "Transmission Systems" is given. It explains basic principles, circuits and systems of electrical and optical transmission systems. Short intellectual impulses, which address professional, intercultural and ethical issues of engineers' working life are integrated into this regular lecture. In each lecture unit, an impulse with one specific topic is given approximately in the middle of the lecture hour. An evaluation was done at the end of the semester, which shows that most of the students remember the discussed topics and state high interest due to high importance for their professional life. Due to these encouraging results, this concept will be developed further.}, language = {en} } @article{SteinkirchnerFuhrmannNiemetz, author = {Steinkirchner, Alfons and Fuhrmann, Thomas and Niemetz, Michael}, title = {Channel Coded Processor for Enhanced Safety}, series = {International Journal of Future Computer and Communication (IJFCC)}, volume = {6}, journal = {International Journal of Future Computer and Communication (IJFCC)}, number = {2}, publisher = {International Association of Computer Science and Information}, address = {Singapore}, issn = {2010-3751}, doi = {10.18178/ijfcc.2017.6.2.489}, pages = {58 -- 62}, abstract = {Several concepts are known for improving processor safety, all of them having their pros and cons. Some are very resource intensive, others have limited capabilities regarding the provided error safety. In this paper we use research on channel coding of noisy communication channels known from communication theory as an analogy to random bit errors in processors. We incorporate this knowledge into processor design to suggest a new error correction concept by using channel coding in processors. The new concept of a Channel Coded Processor could provide effective implementation of redundancy by the channel coding that enables error correction. The concept could also create a complete chain of redundancy in all areas and components of the processor ranging from the code compiler through the processing hardware to the output of the information.}, language = {en} } @inproceedings{FuhrmannNiemetz, author = {Fuhrmann, Thomas and Niemetz, Michael}, title = {Transdisciplinary Bachelor Course Connecting Business and Electrical Engineering}, series = {4th International Conference on Higher Education Advances (HEAd'18), 2018, Universitat Polit{\`e}cnica de Val{\`e}ncia, Val{\`e}ncia}, booktitle = {4th International Conference on Higher Education Advances (HEAd'18), 2018, Universitat Polit{\`e}cnica de Val{\`e}ncia, Val{\`e}ncia}, doi = {10.4995/HEAd18.2018.8056}, abstract = {The OTH Regensburg has a broad variety of study programs in technical, business, social and health sciences. Up to now there is no integral connection in the bachelor curricula between business and technical faculties except for some small subjects. The scope of this project is to develop a new course specialization which connects engineering and business thinking. Electrical engineering students should learn basics of business science and how managers think. Business students should vice versa learn fundamentals of engineering and how engineers solve problems. Students from both faculties work together in projects where they act like start-up companies developing a new product and bringing it into the market. It is seen a transdisciplinary effect: These projects gain innovative results between the disciplines compared to student projects of one isolated discipline. Evaluation results from the first two cohorts indicate high student satisfaction, high learning success as well as directions for further improvement.}, language = {en} } @book{AltmannGebhardEmbergeretal., author = {Altmann, Robert and Gebhard, J{\"u}rgen and Emberger, Peter and Thuneke, Klaus and Rabl, Hans-Peter and Remmele, Edgar}, title = {Z{\"u}nd- und Brennverhalten von Pflanzen{\"o}lkraftstoff und {\"U}bertragung auf einen Motor der Abgasstufe V}, volume = {69}, publisher = {Technologie- und F{\"o}rderzentrum im Kompetenzzentrum f{\"u}r Nachwachsende Rohstoffe}, address = {Straubing}, issn = {1614-1008}, pages = {188}, abstract = {Durch den Ersatz von Dieselkraftstoff durch Raps{\"o}lkraftstoff (R100) k{\"o}nnen Treibhausgasemissionen reduziert werden. F{\"u}r einen st{\"o}rungsfreien Betrieb eines Motors mit Raps{\"o}lkraftstoff sind jedoch Modifikationen an Motorkomponenten und Motorsteuerger{\"a}t notwendig, um eine effiziente Verbrennung im Motor zu erreichen. Ziel des Vorhabens ist die Erarbeitung von Grundlagen zur Auslegung der Motorsteuerung pflanzen{\"o}ltauglicher Offroad-Motoren mit moderner Abgasnachbehandlung mit anschließender entsprechender Abstimmung der Motorapplikation am Pr{\"u}fstand. Grundlegende Untersuchungen der physikalischen Prozessabl{\"a}ufe von R100 bei der Einspritzung werden an einem hydraulischen Druckanstiegsanalysator (HDA) und einer Hochdruck-Hochtemperatur-Kammer (HDHT-Kammer) durchgef{\"u}hrt. Unterschiede im Z{\"u}nd- und Brennverhalten werden in einer Konstantvolumenbrennkammer untersucht. Abschließend werden die Erkenntnisse am Motorenpr{\"u}fstand auf einen DEUTZ-Motor {\"u}bertragen, dessen Einspritzsystem auch bei den grundlegenden Untersuchungen verwendet wurde. Die Ergebnisse zeigen, dass das Einspritzverhalten von R100 eine h{\"o}here Sensitivit{\"a}t gegen{\"u}ber Kraftstofftemperaturvariationen aufweist als Dieselkraftstoff. Bei niedrigen raftstofftemperaturen sind mit R100 ein l{\"a}ngerer {\"O}ffnungsverzug und eine geringere Einspritzmenge festzustellen. Um diesen Einfluss bei der Einspritzstrategie zu kompensieren, ist die Kenntnis der Kraftstofftemperatur im Injektor notwendig. Eine weitere Herausforderung stellt die Gemischaufbereitung dar, hier f{\"u}hren unter anderem die h{\"o}here Viskosit{\"a}t und h{\"o}here Siedetemperaturen von R100 zu einem schm{\"a}leren Spritzwinkel und verz{\"o}gerter Verdampfung im Vergleich zum Dieselkraftstoff. Eine Erh{\"o}hung des Einspritzdrucks und h{\"o}here Temperaturen und Dr{\"u}cke in der Brennkammer verbessern die Gemischaufbereitung. Bei Bedingungen von mittlerer und hoher Last ist der Z{\"u}ndverzug von R100 k{\"u}rzer und das Verbrennungsverhalten {\"a}hnlich zum Dieselkraftstoff. Eine geringere W{\"a}rmefreisetzung von R100 wird durch den geringeren Heizwert verursacht. Unter Bedingungen von niedriger Last und Motorstart ist ein l{\"a}ngerer Z{\"u}ndverzug von R100 im Vergleich zum Dieselkraftstoff festzustellen. Eine Steigerung des Einspritzdrucks und h{\"o}here Brennkammerdr{\"u}cke und -temperaturen f{\"u}hren bei beiden Kraftstoffen zu k{\"u}rzeren Z{\"u}ndverz{\"u}gen, der Einfluss dieser Parameter ist jedoch f{\"u}r R100 st{\"a}rker als f{\"u}r Dieselkraftstoff. Voreinspritzungen f{\"u}hren bei beiden Kraftstoffen zu einer Verk{\"u}rzung des Z{\"u}ndverzugs der Haupteinspritzung und zu einer geringeren W{\"a}rmefreisetzungsrate. Am Motorpr{\"u}fstand ist bei gleicher Motorapplikation mit R100 eine geringere Leistung als mit Dieselkraftstoff festzustellen. Nach Angleichung der Motorleistung durch Anhebung der Einspritzmenge von R100 sind im Rohabgas Stickstoffoxid (NOX)- und Kohlenstoffmonoxidemissionen auf gleichem Niveau zu Dieselkraftstoff zu beobachten sowie geringere Partikelemissionen. Unter Verwendung eines DoE Vorgehens kann der Partikel-NOX - trade-off von R100 optimiert und Einstellparameter gefunden werden, in denen sowohl niedrigere NOX als auch niedrigere Partikelemissionen im Vergleich zum Dieselkraftstoff resultieren. Das installierte Abgasnachbehandlungssystem, bestehend aus einem Dieseloxidationskatalysator (DOC), Dieselpartikelfilter (DPF) und selektivem katalytischem Reduktionssystem (SCR), arbeitet f{\"u}r beide Kraftstoffe {\"a}hnlich und es scheint keine Anpassung der Dosierungsstrategie der w{\"a}ssrigen Harnstoffl{\"o}sung notwendig zu sein. Eine Regeneration des Partikelfilters mit R100 war nach Optimierung der Einstellparameter der Drosselklappe m{\"o}glich. Motorkaltstart und Leerlauf sind herausfordernde Betriebsphasen, die f{\"u}r R100 einer weiteren Optimierung bed{\"u}rfen. Eine Temperierung von R100 im Injektor auf 50-60 °C sowie eine Kompensation der Einspritzmenge in Abh{\"a}ngigkeit von der Kraftstofftemperatur sind m{\"o}gliche Verbesserungsmaßnahmen. Zudem kann durch einen fr{\"u}heren Einspritzbeginn von R100 das Verbrennungsverhalten angepasst werden. Die Motorpr{\"u}fstandsuntersuchungen best{\"a}tigen qualitativ die Erkenntnisse die mit dem hydraulischen Druckanstiegsanalysator (HDA), der Hochdruck-Hochtemperatur-Kammer (HDHT-Kammer) und der Konstantvolumenbrennkammer gewonnen wurden. Weitere Untersuchungen sind notwendig, um die Ergebnisse auf einen baugleichen, in einer mobilen Arbeitsmaschine eingebauten Motor zu transferieren, damit Informationen zur Dauerhaltbarkeit unter realen Bedingungen erhalten werden k{\"o}nnen. Weiterf{\"u}hrende Forschungsarbeiten sind im Bereich der Betriebsphasen des Motorkaltstarts und Leerlaufs mit Raps{\"o}lkraftstoff n{\"o}tig, um einen dauerhaft st{\"o}rungsfreien Betrieb in diesen Betriebsphasen zu erreichen. Die erzielten Erkenntnisse deuten darauf hin, dass hier noch viel Verbesserungspotenzial vorhanden ist.}, subject = {Biokraftstoff}, language = {de} } @incollection{ArrietaCastroRillWeber, author = {Arrieta Castro, Abel and Rill, Georg and Weber, Hans I.}, title = {Development of a Robust Integrated Control System to Improve the Stability of Road Vehicles}, series = {Multibody Mechatronic Systems}, volume = {54}, booktitle = {Multibody Mechatronic Systems}, editor = {Carvalho, Jo{\~a}o Carlos Mendes and Martins, Daniel and Simoni, Roberto and Simas, Henrique}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-67566-4}, doi = {10.1007/978-3-319-67567-1_48}, pages = {506 -- 516}, abstract = {Nowadays, new technologies are pushing the road vehicle limits further. Promising applications, e.g., self-driving cars, require a suitable control system that can maintain the vehicle's stability in critical scenarios. In most of current cars, the control systems actuates independently, meaning there is not a coordination or data sharing between them. This approach can produce a conflict between these standalone controllers and thus, no improvements on the vehicle's stability are achieved or even a worse scenario can be generated. In order to overcome these problems, an integrated approach is developed in this work. This integration, defined in this work as Integrated Control (IC), is done by an intelligence coordination of all standalone controllers inside the vehicle, i.e., Anti-Lock Braking System (ABS), Electronic Stability Program (ESP) and Four-Wheel Steering System (4WS). The ABS model was built using Fuzzy logic, for which only three rules were necessary to get a good performance. To design the ESP and the 4WS, the simple handling vehicle model was used as a reference behavior. The IC was designed using the hierarchical approach with two layers, i.e., the upper and lower layer. The upper one, observes the side slip angle and depends of its value the upper layer triggers the ESP or the 4WS. Finally, in order to prove the improvements of the IC system over the non-integrated approach, a full-size vehicle model was used to perform simulation in run-off-road and μ-split scenarios.}, language = {en} } @inproceedings{HacklHirschbergLexetal., author = {Hackl, Andreas and Hirschberg, Wolfgang and Lex, Cornelia and Rill, Georg}, title = {Tyre Dynamics: Model Validation and Parameter Identification}, series = {Proceedings of the European Automotive Congress EAEC-ESFA 2015}, volume = {45}, booktitle = {Proceedings of the European Automotive Congress EAEC-ESFA 2015}, editor = {Andreescu, Cristian and Clenci, Adrian}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-27275-7}, doi = {10.1007/978-3-319-27276-4_20}, pages = {219 -- 232}, abstract = {The present paper deals with the experimental validation of tyre dynamics approaches as it is widely applied in tyre models for vehicle dynamics and handling. Firstly it gives a brief derivation of two modelling principles regarding the deflection velocity in the considered direction of the tyre's deformation. This is than followed by a brief description of the performed measurement procedure. From the measurements, a set of model parameters of the considered tyre, depending on different manoeuvre speeds and frequencies, is identified, where no particular fitting parameters for the tyre dynamics are needed. Based on these model parameters, the related dynamic simulations are carried out. The comparisons show that the applied first-order model describes the behaviour quite well within a certain operation range, whereas the second-order approach cannot deliver better results in spite of the longer computational time. However, for investigations within an enlarged frequency range of the steer input and at high slip angles, a more detailed model is recommended.}, language = {en} } @inproceedings{HopfenspergerDaubnerHerrmannetal., author = {Hopfensperger, Bernhard and Daubner, Andreas and Herrmann, Fabian and Hopkins, Andrew and Mellor, Phil}, title = {Investigation of Shifted PWM Methods for a Dual Three-Phase System to Reduce Capacitor RMS Current}, series = {PCIM Europe Digital Days 2020: International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management: 07.-08.07.2020, Online [proceedings]}, booktitle = {PCIM Europe Digital Days 2020: International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management: 07.-08.07.2020, Online [proceedings]}, publisher = {VDE-Verlag}, address = {Berlin, Offenbach}, isbn = {978-3-8007-5245-4}, pages = {124 -- 131}, abstract = {Mild hybrid automotive topologies containing a 48V high power (>15 kW) electric drive system demand a high integration of power electronics and electrical machine. A multi-phase motor winding topology helps to keep the per-phase operating currents to a reasonable level. Close integration and multi-phase system have led to a drive system with dual 3-phase systems supplied by a common 48V DC-link, which allows to shift PWM patterns for reduction of DC-link capacitor ripple current and size. This paper derives some basic rules for combinations of common PWM methods for dual 3-phase systems without magnetic cross-coupling. Experimental measurements verify simulated results.}, subject = {Elektroantrieb}, language = {en} } @inproceedings{Becke, author = {Becke, Mark}, title = {On Modeling and Least Squares Fitting of Cylinders from Single and Multiple Views Using Contour Line Features}, series = {Intelligent Robotics and Applications}, volume = {9246}, booktitle = {Intelligent Robotics and Applications}, editor = {Liu, Honghai and Kubota, Naoyuki and Zhu, Xiangyang and Dillmann, R{\"u}diger}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-22872-3}, doi = {10.1007/978-3-319-22873-0_33}, pages = {372 -- 385}, abstract = {In this paper, a new method for a minimum-error pose estimation of cylinder axes based on apparent contour line features from multiple views is presented. Novel model equations for both single and particularly multiple views are derived, and based upon these, an algorithm for least squares fitting the model to imaged cylinder contour line features is introduced. The good performance of the proposed algorithm is shown by solving an exemplary fitting problem.}, language = {en} } @inproceedings{BoehmSchorrZimmermannetal., author = {B{\"o}hm, Valter and Schorr, Philipp and Zimmermann, Klaus and Zentner, Lena}, title = {An Approach to the Estimation of the Actuation Parameters for Mobile Tensegrity Robots with Tilting Movement Sequences}, series = {2018 International Conference on Reconfigurable Mechanisms and Robots (ReMAR); 20-22 June 2018; Delft, Netherlands}, booktitle = {2018 International Conference on Reconfigurable Mechanisms and Robots (ReMAR); 20-22 June 2018; Delft, Netherlands}, publisher = {IEEE}, doi = {10.1109/REMAR.2018.8449871}, pages = {1 -- 8}, abstract = {This paper deals with the locomotion by tilting sequences of shape-variable compliant tensegrity structures. The shape of these structures is controlled by manipulating their prestress state. The tensegrity structure is tilting as consequence of a suitable variation of its shape. By multiple repetition of such tilting sequences a motion is generated. Quasi-static considerations for the considered structures are presented in order to estimate the actuation parameters. For a proper number of actuators this quasi-static approach enables an analytical calculation of the actuation parameters of the structure in order to control the geometrical configuration as required. As an example a two-dimensional tensegrity structure which is in contact with a horizontal plane due to gravity is considered. By successive tilting sequences a uniaxial motion results. The excitation of the structure is calculated for a given change of shape with the quasi-static analysis. The according results are compared with transient dynamic simulations. Qualitative conclusions about the motion behavior and the usability of the quasi-static approach are given.}, language = {en} } @inproceedings{Briem, author = {Briem, Ulrich}, title = {Fatigue Behaviour of Rope Wires}, series = {Proceedings of the OIPEEC Conference, La Rochelle, France, 12th - 15th March 2019}, booktitle = {Proceedings of the OIPEEC Conference, La Rochelle, France, 12th - 15th March 2019}, editor = {Dohm, Martin}, publisher = {OIPEEC}, abstract = {The rope curve line of a tensioned rope can be described by means of the catenary curve. Opposed to that, the curved line of a free bent rope cannot be described by an analytical function. Practical applications of free bending are for example at tail ropes at the bottom of shaft in rope drives with traction sheaves. The question whether the maximum diameter of rope loop is small enough for the diameter of the shaft is highly interesting. In [1] a method was presented to calculate the curved line of free bent ropes numerically by help of energy methods. An analytical description of rope curve line would be very helpful. Beginning with the structure of a rope curve line of tensioned rope (catenary curve) and considering the influence of bending stiffness, the structure of an analytical equation for the curve line of a free bent rope will be developed. The main focus of this paper is to develop and to describe the structure of such an analytical equation. To get a first idea about the values of the constants in that analytical equation a few test results were evaluated. But these equations consider the static rope behavior only. Due to dynamic effects in the rope while running through the loop at the bottom of a shaft, pendulousness of the tail rope occurs.}, language = {en} } @inproceedings{Briem2019, author = {Briem, Ulrich}, title = {Mathematical Approach to Curve Line of free bent Ropes}, series = {Proceedings of the OIPEEC Conference, La Rochelle, France, 12th - 15th March 2019}, booktitle = {Proceedings of the OIPEEC Conference, La Rochelle, France, 12th - 15th March 2019}, editor = {Dohm, Martin}, publisher = {OIPEEC}, year = {2019}, abstract = {The rope curve line of a tensioned rope can be described by means of the catenary curve. Opposed to that, the curved line of a free bent rope cannot be described by an analytical function. Practical applications of free bending are for example at tail ropes at the bottom of shaft in rope drives with traction sheaves. The question whether the maximum diameter of rope loop is small enough for the diameter of the shaft is highly interesting. In [1] a method was presented to calculate the curved line of free bent ropes numerically by help of energy methods. An analytical description of rope curve line would be very helpful. Beginning with the structure of a rope curve line of tensioned rope (catenary curve) and considering the influence of bending stiffness, the structure of an analytical equation for the curve line of a free bent rope will be developed. The main focus of this paper is to develop and to describe the structure of such an analytical equation. To get a first idea about the values of the constants in that analytical equation a few test results were evaluated. But these equations consider the static rope behavior only. Due to dynamic effects in the rope while running through the loop at the bottom of a shaft, pendulousness of the tail rope occurs.}, language = {en} } @inproceedings{SchneiderMuehlbauerSittletal., author = {Schneider, Sebastian and M{\"u}hlbauer, Christian and Sittl, Christopher and Rottengruber, Hermann and Rabl, Hans-Peter and Wagner, Marcus and Verhey, Jesko L.}, title = {Tickerger{\"a}uschanalyse an einem Otto-DI-Motor mittels empirischer Bewertungsformel}, series = {Motor- und Aggregate-Akustik: 11. Magdeburger Symposium, Tagungsband}, booktitle = {Motor- und Aggregate-Akustik: 11. Magdeburger Symposium, Tagungsband}, editor = {Rottengruber, Hermann and Luft, Tommy and Schneider, Sebastian}, publisher = {Otto-von-Guericke-Universit{\"a}t}, address = {Magdeburg}, isbn = {978-3-948749-02-6}, doi = {10.25673/36611}, pages = {65 -- 86}, abstract = {Beim Kauf eines Pkw wird der akustische Qualit{\"a}tseindruck eines Fahrzeugantriebstrangs stetig relevanter. Die wahrgenommene Ger{\"a}uschqualit{\"a}t des Motoraggregates nimmt hierbei eine Schl{\"u}sselrolle ein. Aufgrund der Auspr{\"a}gung einzelner St{\"o}rger{\"a}usche wird jene Ger{\"a}uschqualit{\"a}t negativ beeinflusst. Diese als unangenehm empfundenen Ger{\"a}uschkomponenten gilt es im Rahmen der Fahrzeugentwicklung weiter zu reduzieren, wobei die Identifikation und Bewertung st{\"o}render Ger{\"a}uschanteile am Motorgesamtger{\"a}usch Voraussetzungen f{\"u}r eine effektive Akustikoptimierung sind. Vor allem das impulshafte Tickerger{\"a}usch wird bei Otto-DI-Motoren als besonders l{\"a}stig eingestuft, weswegen dieser Beitrag darauf abzielt, die tickernden Ger{\"a}uschanteile aus dem Gesamtger{\"a}usch zu analysieren und zu bewerten. Hierzu wurde eine empirische Formel entwickelt, welche die tickernden Ger{\"a}uschanteile in ihrer Intensit{\"a}t in Grenzen einstufen kann. Diese ist rein empfindungsbasiert und besteht aus der Impulshaftigkeit, der Lautheit sowie der Sch{\"a}rfe des Motorgesamtger{\"a}usches. Wie auch bei anderen psychoakustischen Bewertungsskalen wurde die Benotung von 1 (sehr tickernd) bis 10 (nicht tickernd) vorgenommen. Anhand von H{\"o}rversuchen mithilfe einer Expertenjury konnte die Tickerger{\"a}uschbewertungsformel anschließend verifiziert werden. Hiernach kann pr{\"a}zise ausgesagt werden, in welchen Motorkennfeldbereichen das Tickerger{\"a}usch die Angenehmheit des Motorgesamtger{\"a}usches untergr{\"a}bt.}, language = {de} } @inproceedings{SchneiderHotsLuftetal., author = {Schneider, Sebastian and Hots, Jan and Luft, Tommy and Rottengruber, Hermann and Verhey, Jesko L. and Rabl, Hans-Peter}, title = {Entwicklung einer empirischen Formel zur Bewertung der Tickerger{\"a}uschanteile von Motorger{\"a}uschen}, series = {DAGA 2019 - 45. Jahrestagung f{\"u}r Akustik, 8.-21. M{\"a}rz 2019, Rostock}, volume = {45}, booktitle = {DAGA 2019 - 45. Jahrestagung f{\"u}r Akustik, 8.-21. M{\"a}rz 2019, Rostock}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, isbn = {978-3-939296-14-0}, pages = {643 -- 646}, language = {de} } @inproceedings{RiegerMuehlbauerWeberetal., author = {Rieger, Anna and M{\"u}hlbauer, Christian and Weber, Rainer and Rabl, Hans-Peter}, title = {Measures to Address the Dissonance Perception of Multiple Tonal Components in Sounds}, series = {DAGA 2019 - 45. Jahrestagung f{\"u}r Akustik, 18.-21. M{\"a}rz 2019, Rostock}, volume = {45}, booktitle = {DAGA 2019 - 45. Jahrestagung f{\"u}r Akustik, 18.-21. M{\"a}rz 2019, Rostock}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, pages = {375 -- 378}, language = {en} } @inproceedings{RiegerOetjenvandeParetal., author = {Rieger, Anna and Oetjen, Arne and van de Par, Steven and Rabl, Hans-Peter}, title = {Einfluss der Dissonanz auf die Wahrnehmung der Ger{\"a}uschqualit{\"a}t}, series = {Fortschritte der Akustik DAGA 2022: 48. Jahrestagung f{\"u}r Akustik, 21. - 24. M{\"a}rz 2022, Stuttgart und Online}, volume = {48}, booktitle = {Fortschritte der Akustik DAGA 2022: 48. Jahrestagung f{\"u}r Akustik, 21. - 24. M{\"a}rz 2022, Stuttgart und Online}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, address = {Stuttgart}, language = {de} } @inproceedings{RiegerOetjenvandeParetal., author = {Rieger, Anna and Oetjen, Arne and van de Par, Steven and Rabl, Hans-Peter}, title = {Geh{\"o}rbezogene Modellierung der Dissonanz}, series = {Tagungsband DAGA 2021: 47. Jahrestagung f{\"u}r Akustik, 15.-18. August 2021, Wien und Online}, volume = {47}, booktitle = {Tagungsband DAGA 2021: 47. Jahrestagung f{\"u}r Akustik, 15.-18. August 2021, Wien und Online}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, pages = {1034 -- 1037}, language = {de} } @misc{AltmannGadererRabl, author = {Altmann, Robert and Gaderer, Matthias and Rabl, Hans-Peter}, title = {Pr{\"u}fstandsuntersuchungen an einem DEUTZ NRMM Motor mit Raps{\"o}lkraftstoff und Optimierung des Betriebs- und Emissionsverhaltens durch statistische Versuchsplanung}, series = {18. Internationaler Fachkongress "Kraftstoffe der Zukunft 2021" - digital \& international vernetzt!, online}, journal = {18. Internationaler Fachkongress "Kraftstoffe der Zukunft 2021" - digital \& international vernetzt!, online}, language = {de} } @misc{AltmannGebhard, author = {Altmann, Robert and Gebhard, J{\"u}rgen}, title = {Ph{\"a}nomenologische Untersuchung des Einspritzprozesses eines Injektors aus dem Off-Highway-Segment mit Diesel- und Raps{\"o}lkraftstoff}, series = {16. Internationaler Fachkongress "Kraftstoffe der Zukunft 2019", Berlin}, journal = {16. Internationaler Fachkongress "Kraftstoffe der Zukunft 2019", Berlin}, language = {de} } @inproceedings{DiamantidisLenziSykora, author = {Diamantidis, Dimitris and Lenzi, Daniele and S{\´y}kora, Miroslav}, title = {Optimal decisions based on monitoring - case study of steel roof}, series = {Proceedings of the Joint COST TU1402-TU1406 - IABSE WC1 Workshop, Zagreb 2-3 March 2017}, booktitle = {Proceedings of the Joint COST TU1402-TU1406 - IABSE WC1 Workshop, Zagreb 2-3 March 2017}, doi = {10.5592/CO/BSHM2017.4.7}, pages = {4.7-1 -- 4.7-7}, abstract = {Monitoring of structures and related decisions based on cost optimization are discussed in this contribution. Many research publications and experimental data are currently available on inspection and on monitoring and they represent the outcome of the remarkable work done. Not all the topics of interest are widely debated and implemented in standards. The current state-of-practice in standards is summarized and aspects to be included in future recommendations are proposed. The implementation of risk-based decisions is illustrated in a case study dealing with a stadium roof in Northern Italy. Snow actions are important especially in northern and mountainous regions where heavy snowfalls and related accumulation result to considerable loads. As the roof structure fails to comply with the requirements of Eurocodes, a permanent monitoring system has been installed to allow for real time evaluation of the reliability level of the structure. The system supplies the necessary information supporting immediate decisions on closure of the stadium in case of an extraordinary snow load. Cost-optimal decisions regarding the closure of the stadium are analysed based on a limit state function, on probabilistic models for the influencing parameters including measurement uncertainty, economic losses related to closure and failure consequences. The results demonstrate the potential of the use of the monitoring systems and probabilistic reliability analysis in order to support decisions and highlight the need for their implementation in future standards.}, language = {en} } @inproceedings{HolickyDiamantidisSykora, author = {Holick{\´y}, Milan and Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Effects of Quality Control on Reliability of Reinforced Concrete Structures according to Eurocodes}, series = {fib Symposium 2016 : Performance-Based Approaches for Concrete Structures, 14, 2016, Cape town}, booktitle = {fib Symposium 2016 : Performance-Based Approaches for Concrete Structures, 14, 2016, Cape town}, abstract = {The effect of quality control on structural reliability represents an increasingly important concern of designers and thus is investigated in this contribution, focusing on reinforced concrete structures. Recent European documents for structural design - Eurocodes, fib Model Code 2010 and ISO 2394:2015 for general principles on structural reliability indicate that the partial factors may be adjusted to available information on the quality control of structures. In particular, the partial factors for concrete and steel strength may be significantly reduced taking into account actual execution quality and related available data. Using probabilistic methods of structural reliability, effects for execution quality are investigated in this contribution considering two fundamental reinforced concrete members: a beam (or slab) exposed to bending and a short column exposed to compression. It is shown that the reliability of reinforced concrete members may vary with the load ratio of variable and permanent actions. It appears also that the structural members of a basic quality, designed using unreduced partial factors, have a greater reliability level than the members of an increased quality, designed using the partial factors reduced according to EN 1992 1 1. This provides the basis for recommendations for further code developments.}, language = {en} } @inproceedings{Neidhart, author = {Neidhart, Thomas}, title = {Bodenphysikalische und bodenmechanische Anforderungen an ZFSV (Fl{\"u}ssigboden) als Bettungsmaterialien erdverlegter Hochspannungsleitungen}, series = {Rohrleitungen in digitalen Arbeitswelten : Tagungsband zum 31. Oldenburger Rohrleitungsforum 2017}, booktitle = {Rohrleitungen in digitalen Arbeitswelten : Tagungsband zum 31. Oldenburger Rohrleitungsforum 2017}, editor = {Wegener, Thomas}, publisher = {Vulkan Verlag}, address = {Essen}, isbn = {978-3-8027-2865-5}, pages = {337}, language = {de} } @article{EbnerElsner, author = {Ebner, Lena and Elsner, Michael}, title = {Thermische Energiespeicher: W{\"a}rmespeicherung in Kugelsch{\"u}ttungen. Numerische Simulation der Stromungs-, Warmetransport- und Entstaubungsvorg{\"a}nge}, series = {BWK. Das Energie-Fachmagazin}, volume = {66}, journal = {BWK. Das Energie-Fachmagazin}, number = {9}, publisher = {VDI-Verlag}, pages = {40 -- 43}, abstract = {Festbettspeicher bieten die M{\"o}glichkeit, thermische Energie auf einem hohen Temperaturniveau zu speichern. Die oft kugelf{\"o}rmigen Sch{\"u}ttg{\"u}ter bestehen aus Materialien hoher Dichte und W{\"a}rmekapazit{\"a}t. Neben der W{\"a}rmespeicherung k{\"o}nnen mithilfe dieser Sch{\"u}ttungen partikelbeladene Abgase entstaubt werden. Die Str{\"o}mungs-, W{\"a}rmetransport- und Entstaubungsvorg{\"a}nge bei der Speicherung von W{\"a}rme in einem Sch{\"u}ttschichtw{\"a}rme{\"u}bertrager werden in Zusammenarbeit mit Fraunhofer Umsicht, Institutsteil Sulzbach-Rosenberg, untersucht. Einen entscheidenden Aspekt der Arbeiten stellt die numerische Simulation der im W{\"a}rme{\"u}bertrager ablaufenden Vorg{\"a}nge dar. Die transiente Simulation von Sch{\"u}ttschichtw{\"a}rme{\"u}bertragern ist nur mit Vereinfachungen m{\"o}glich, da aufgrund der komplexen Geometrie und der daraus folgenden feinen Vernetzung eine enorme Rechenleistung ben{\"o}tigt wird. Bei den in diesem Beitrag vorgestellten Ergebnissen werden die physikalischen Vorgange in einem Ausschnitt der Sch{\"u}ttschicht simuliert, in dem die Kugelgeometrie detailliert modelliert ist. Die Ergebnisse der numerischen Simulation werden durch analytische Berechnungen aus der Literatur best{\"a}tigt. Eine Reihe von Parametervariationen zeigen die Einfl{\"u}sse verschiedener Gr{\"o}ßen beispielsweise auf den Druckverlust sowie den Unterschied zwischen radialer und axialer Durchstr{\"o}mung einer Sch{\"u}ttschicht. Die Entstaubung partikelbeladener Gase innerhalb einer Sch{\"u}ttschicht wird zun{\"a}chst anhand einer Einzelkugel untersucht; die Erweiterung auf die Entstaubung in einer Kugelpackung ist vorgesehen. Die Ergebnisse der numerischen Simulationen sollen mit den an einem Versuchsstand experimentell bestimmten Daten verglichen werden.}, language = {de} } @inproceedings{MaeuleRabl, author = {M{\"a}ule, Paul and Rabl, Hans-Peter}, title = {Correlation of Oil Emissions with Particulate Emissions of Gasoline Engines}, series = {Internationales AVL-Forum Abgas- und Partikelemissionen, 20. und 21. Februar 2018, Ludwigsburg}, booktitle = {Internationales AVL-Forum Abgas- und Partikelemissionen, 20. und 21. Februar 2018, Ludwigsburg}, publisher = {AVL Deutschland}, address = {Mainz}, pages = {1 -- 9}, abstract = {Recent developments in exhaust gas legislation make it necessary to focus the research at the particulate emissions from gasoline engines and technologies for their reduction. In addition to the particulates resulting from the combustion of the fuel, the oil emissions represent another possible source for particulate emissions. This paper presents a measurement method which can be used to quantify stationary as well as dynamic oil emissions of gasoline engines. Furthermore, the correlation between the oil emissions and the particulate emissions is the focus of the investigations. Conventional methods for the determination of the oil emissions, such as the gravimetric and the volumetric measurement, are unsuitable since they require long engine operation times to provide useful results. These methods therefore do not allow a fast online measurements during the dynamic operation. For this reason, a new measuring method was used, which allows for a time-resolved online measurement of the oil emissions. This measurement method is based on the sulfur tracer method, which uses the sulfur that is naturally contained in the engine oil as a tracer. The sulfur concentration in the exhaust gas is determined by using an Ion-Molecule-Reaction mass spectrometer. The determination of the particulate emissions corresponds to the PMP regulation. The studies carried out under steady state and dynamic conditions show a clear correlation between the oil consumption and the number of particulates in the exhaust gas. In the case of the dynamic measurements it could also be shown that time-resolved measurements of the oil consumption are possible with the used measurement setup. In addition, it was shown that the number of particulates does not influence the measurement of the SO2-concentration. Furthermore, the different effects of burned and unburned oil emissions have been evaluated by the dosing of the oil into the exhaust gas. The overall conclusion of the measurements shows a strong influence of the oil emissions on the particulate emissions. Therefore, it is crucial to reduce the oil emissions. Possible approaches for this reduction can be improved turbocharger sealing concepts, new piston ring designs or more efficient oil separators for the crankcase ventilation system.}, language = {en} } @inproceedings{DessortChucholowskiRill, author = {Dessort, Ronnie and Chucholowski, Cornelius and Rill, Georg}, title = {Parametrical approach for modeling of tire forces and torques in TMeasy 5}, series = {Proceedings of the 16. Internationales Stuttgarter Symposium Automobil- und Motorentechnik}, booktitle = {Proceedings of the 16. Internationales Stuttgarter Symposium Automobil- und Motorentechnik}, editor = {Bargende, Michael and Reuss, Hans-Christian and Wiedemann, Jochen}, publisher = {Springer}, address = {Wiesbaden}, isbn = {978-3-658-13254-5}, pages = {435 -- 449}, abstract = {For the dynamic simulation of on-road vehicles, the model-element "tire/road" is of special importance, according to its influence on the achievable results. Sufficient description of the interaction between tire and road is one of the most challenging tasks of vehicle modeling. Two groups of tire models can be classified: handling models and structural or high-frequency models. Usually, various assumptions are made in modeling vehicles as multibody systems. Therefore, in the interest of balanced modeling, the precision of the complete vehicle model should stand in reasonable relation to the performance of the applied tire model. Handling tire models are characterized by a useful compromise between user friendliness, model complexity, and efficiency in computation time on the one hand, and precision in representation on the other hand. The present paper describes the general approach of the semi-physical tire model TMeasy for vehicle dynamics and handling simulation and its enhancement for bore torque simulation in Version TMeasy 5. A parameter fitting process realized by TESIS DYNAware and the validation of real tire behavior by simulation with DYNA4 is presented. Even with first guess parameters, the TMeasy tire model behaves in a realistic and plausible manner. Parameter estimation is intuitive and datasets from previous model versions can be easily migrated. After parameter fitting, the simulation results correlate well with both the tire test rig and full vehicle measurements. The enhancement of a three-dimensional slip calculation in the latest version does not modify the model behavior for high slip conditions, but improves the results not only for highly dynamic situations but also for low speed maneuvers such as parking.}, language = {en} } @inproceedings{SmolareckFaisstSchneider, author = {Smolareck, Elisabeth and Faisst, Holger and Schneider, Ralph}, title = {Modellbasierte Korrektur von Inertialsensor-Signalen - Ein Schritt auf dem Weg zum hochautomatisierten Fahren}, series = {Konferenz: AALE 2018 - 15. Fachkonferenz, Das Forum f{\"u}r Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft 01.03.2018 - 02.03.2018 in K{\"o}ln, Deutschland}, booktitle = {Konferenz: AALE 2018 - 15. Fachkonferenz, Das Forum f{\"u}r Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft 01.03.2018 - 02.03.2018 in K{\"o}ln, Deutschland}, publisher = {VDE-Verlag}, address = {Berlin}, isbn = {978-3-8007-4522-7}, pages = {1 -- 10}, abstract = {Infolge neuer Zielsetzungen im Automobilbereich, wie z. B. der Weiterentwicklung von Fahrerassistenzsystemen hin zum hochautomatisierten Fahren (HAF), ergeben sich erh{\"o}hte Anforderungen an die Signalg{\"u}te der im Fahrzeug eingesetzten Inertialsensoren f{\"u}r Drehraten und Beschleunigungen. Da deren Erf{\"u}llung {\"u}ber einen hardwarebasierten Ansatz nicht immer m{\"o}glich und sinnvoll ist, strebt die Firma Continental eine Software-L{\"o}sung zur modellbasierten Verbesserung dieser Sensorsignale an.}, language = {de} } @inproceedings{HofmannScharfenberg, author = {Hofmann, Gerhard and Scharfenberg, Georg}, title = {{\"U}berlegungen zur normativen Anpassung der ISO 26262 aufgrund des autonomen Fahrens}, series = {Automotive Software Kongress, 2015}, booktitle = {Automotive Software Kongress, 2015}, publisher = {WEKA Fachmedien}, address = {Haar}, pages = {1 -- 6}, abstract = {In der Automobilindustrie ist neben der Elektromobilit{\"a}t und dem Leichtbau auch das Gebiet der Fahrerassistenz ein Zukunftsfeld. Speziell Fahrerassistenzsysteme, wie z.B. der Stauassistent, sind in Hinblick auf das autonome Fahren als dessen Vorstufe zu sehen. Aktuelle Assistenzfunktionen basieren auf der Pr{\"a}senz des Fahrers. Die Fahrerassistenzsysteme sind nur durch Funktionen der Elektrik/Elektronik erm{\"o}glicht worden. Durch Maßnahmen der "Funktionalen Sicherheit" m{\"u}ssen Risiken, die durch Fehler der Elektrik/Elektronik zu Gefahren f{\"u}hren k{\"o}nnten, unter eine akzeptierte Grenze gesenkt werden. Die Diskussion {\"u}ber die gesetzlichen Grundlagen f{\"u}r das autonome Fahren ist erst am Anfang des {\"o}ffentlichen Interesses. In diesem Zusammenhang ist es sinnvoll, die Notwendigkeit der Anpassung der bestehenden normativen Anforderungen zur funktionalen Sicherheit in die Diskussion mit einzubeziehen. Im ersten Ansatz wird in diesem Paper untersucht, ob von anderen Anwendungen mit automatisiertem Fahrbetrieb, wie er bei Schienenfahrzeugen realisiert ist, Ableitungen m{\"o}glich sind. Im zweiten Ansatzpunkt wird konkret unter dem Gesichtspunkt des autonomen Fahrens zum Automobil auf die Gefahren-und Risikoanalyse, gem{\"a}ß ISO 26262 Teil 3 eingegangen. Im Rahmen dieser Diskussion werden die drei Bewertungskriterien der Gefahren- und Risikoanalyse (severity, probability of exposure and controllability) im Paper beleuchtet. Es wird gezeigt, dass f{\"u}r autonomes Fahren ein zus{\"a}tzliches Bewertungskriterium der Situationskomplexit{\"a}t sinnvoll ist, das das Umfeld einbezieht. Denn die Kontrollierbarkeit ist auf den Fahrer bezogen. Bei dem neuen Kriterium werden unter anderem der Einfluss durch die Verkehrsdichte sowie die Car-2-Car Kommunikation oder auch Fehler bzw. Ausf{\"a}lle in der Car-2-X Kommunikation (zur Infrastruktur) ber{\"u}cksichtigt.}, language = {de} } @inproceedings{KasparRabl, author = {Kaspar, Marcel and Rabl, Hans-Peter}, title = {Differenzierte Kohlenwasserstoffanalytik im Dieselabgas bei verschiedenen Motorbetriebszust{\"a}nden}, series = {12. FAD-Konferenz „Herausforderung - Agbasnachbehandlung f{\"u}r Dieselmotoren", 12, 2014, Dresden}, booktitle = {12. FAD-Konferenz „Herausforderung - Agbasnachbehandlung f{\"u}r Dieselmotoren", 12, 2014, Dresden}, publisher = {F{\"o}rderkreis Abgasnachbehandlungstechnologien f{\"u}r Verbrennungskraftmaschinen (FAD) e.V.}, pages = {45 -- 59}, abstract = {Die f{\"u}r Dieselfahrzeuge gesetzlich vorgeschriebenen Grenzwerte bez{\"u}glich der Schadstoffkomponenten Kohlenwasserstoffe und Kohlenmonoxid k{\"o}nnen nur durch den Einsatz eines Diesel-Oxidationskatalysators erf{\"u}llt werden. Um erh{\"o}hte Emissionen infolge eines gesch{\"a}digten Katalysators zu vermeiden, gilt es, dieses abgasrelevante Bauteil auch w{\"a}hrend des Betriebes zu {\"u}berwachen. Die zuk{\"u}nftigen gesetzlichen Anforderungen an die {\"U}berwachung erfordern ein Verfahren das eine zuverl{\"a}ssige und hochgenaue Diagnose zul{\"a}sst. Deshalb entwickelt eine Forschungsgemeinschaft aus Industrieunternehmen und Hochschulen einen neuartigen Kohlenwasserstoffsensor zur hochgenauen Analyse von unverbrannten Kohlenwasserstoffen im Abgasstrang. Hierf{\"u}r ist die Kohlenwasserstoffzusammensetzung des Dieselabgases bei verschiedenen Motorbetriebszust{\"a}nden zu ermitteln. Zur differenzierten Untersuchung der Kohlenwasserstoffkomponenten wurde in der Arbeit ein Massenspektrometer eingesetzt, das mit chemischer Ionisation arbeitet. Anhand eines Abgasscreenings konnte eine Reihe von Kohlenwasserstoffen (Alkane, Alkene, Alkine, Alkadiene und aromatische Kohlenwasserstoffe) identifiziert werden, die typisch f{\"u}r das Dieselabgas stehen. Die Molek{\"u}le Ethin, Ethen und Propen wurden gezielt betrachtet. Die Ergebnisse zeigen, dass bei kalten Betriebsbedingungen diese drei Komponenten etwa die H{\"a}lfte der Gesamtkohlenwasserstoffkonzentration ergeben. Ein weiterer Punkt der Untersuchungen war die Diesel-Partikelfilter-Regeneration. Wie erwartet, lassen sich Kohlenwasserstoffmolek{\"u}le mit h{\"o}heren Massen feststellen, die auf unverbrannten Dieselkraftstoff zur{\"u}ckzuf{\"u}hren sind. Anhand der Ergebnisse zeigte sich.dass sich das mit chemischer Ionisation arbeitende Massenspektrometer hervorragend f{\"u}r ein Abgasscreening eignet. Zahlreiche Kohlenwasserstoffe konnten identifiziert werden, die repr{\"a}sentativ f{\"u}r das Dieselabgas stehen. Es sollten Molek{\"u}le bei verschiedenen Motorbetriebsbedingungen untersucht werden, die einen m{\"o}glichst großen Anteil an der Gesamtkohlenwasserstoffkonzentration besitzen. Die Auswahl fiel aufgrund der gemessenen Massenspektren, vor und nach dem Diesel-Oxidationskatalysator, auf die Komponenten Ethin, Ethen und Propen. Zudem kann bei diesen Molek{\"u}len eine Masseninterferenz mit anderen Abgaskomponenten ausgeschlossen werden. Im unteren Teillastbereich und kaltem Motor machen diese Kohlenwasserstoffe bis zu 50\%, gemittelt {\"u}ber alle Messstellen vor, im und nach dem Diesel-Oxidationskatalysator, der Gesamtkohlenwasserstoffkonzentration aus. Bei betriebswarmem Motor reduziert sich ihr Anteil auf ein Drittel Die h{\"o}chste Konzentration unter den drei Komponenten besitzt dabei Propen. Mit steigendem Drehmoment nimmt der Anteil dieser drei Komponenten fortlaufend ab,was daf{\"u}r spricht, dass Molek{\"u}le mit h{\"o}heren Massen einen h{\"o}heren Anteil einnehmen. Die Kohlenwasserstoff-Emissionen bewegen sich bei diesen Motorbetriebspunkten mit betriebswarmem Katalysator jedoch bereits bei sehr niedrigen Werten. W{\"a}hrend der untersuchten Diesel-Partikelfilter-Regeneration mit sp{\"a}ten Nacheinspritzungen zur Abgastemperaturerh{\"o}hung lassen sich Molek{\"u}le mit h{\"o}heren Massen nachweisen. Diese sind typisch f{\"u}r die Reinkomponente Dieselkraftstoff. Der Anteil von Ethin, Ethen und Propen an der THC-Konzentration betr{\"a}gt dann ca. 40\%.}, language = {de} } @inproceedings{MilaevRuiderSchlegl, author = {Milaev, Johannes and Ruider, Martin and Schlegl, Thomas}, title = {Entwicklung eines Experimentalsystems zur Validierung adaptiver Regelungen mit einem OEM-Steuerger{\"a}t}, series = {Tagungsband AALE 2014 : das Forum f{\"u}r Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft ; 11. Fachkonferenz, Regensburg}, booktitle = {Tagungsband AALE 2014 : das Forum f{\"u}r Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft ; 11. Fachkonferenz, Regensburg}, publisher = {Deutscher Industrieverlag}, address = {M{\"u}nchen}, isbn = {978-3-8356-7142-3}, pages = {241 -- 250}, abstract = {Im Rahmen des Kooperationsprojektes "ACES" (Integrated Adaption of Linear Controllers for Embedded Systems) ist ein Pr{\"u}fstand zur Validierung adaptiver Regelungen entwickelt und aufgebaut worden, der das dynamische Verhalten eines Kfz-Antriebstrangs aufweist. Ziel ist es, verschiedene Adaptionsverfahren auf ihre Einsetzbarkeit in OEM-Steuerger{\"a}ten, die im Automotive-Bereich auf breiter Basis verwendet werden, kosteng{\"u}nstig testen zu k{\"o}nnen. Das Problem der aktiven Schwingungsd{\"a}mpfung in Kfz-Antriebsstr{\"a}ngen mit unbekannten und ver{\"a}nderlichen mechanischen Parametern stellt eine Pilotanwendung dar. Ein leicht anpassbarer mechanischer Pr{\"u}fstand dient hierbei als vereinfachtes Modell eines Antriebstrangs. Dieser ist Bestandteil eitles Experimentalsystems mit einer informationstechnischen Architektur, die einen Betrieb engebetteter Regelungssysteme auf verschiedenen Plattformen gestattet. Das flexible mechanische und informationstechnische Design des Experimentalsystems gestattet die Variation von Parametern der zu regelnden Applikation durch leicht austauschbare mechanische Komponenten und gezielte Einbringung von St{\"o}rgr{\"o}ßen. Zudem kann die Berechnung der Regelungsarchitektur auf einem Industrie-PC oder einem Steuerger{\"a}t erfolgen. Weitere Vorteile des entwickelten Experimentalsystems sind die Ber{\"u}cksichtigung von Effekten, die aus dem Verhalten realer Sensoren und der CAN-basierten Signal{\"u}bertragung entstehen. Insbesondere der Einfluss von Wortbreite und Latenz {\"u}bertragener Signale auf die Adaption von Regelungen kann mit Hilfe des vorgestellten Experimentalsystems eingehend untersucht werden.}, language = {de} } @inproceedings{KetterlHeinrichReitmeieretal., author = {Ketterl, Hermann and Heinrich, Tobias and Reitmeier, Torsten and Hoelscher, Clemens}, title = {Emissionsabh{\"a}ngige Leistungsregelung f{\"u}r BHKW's}, series = {Tagungsband AALE 2020: Automatisierung und Mensch-Technik-Interaktion, 17. Fachkonferenz, 4. bis 6. M{\"a}rz 2020, Leipzig}, volume = {2020}, booktitle = {Tagungsband AALE 2020: Automatisierung und Mensch-Technik-Interaktion, 17. Fachkonferenz, 4. bis 6. M{\"a}rz 2020, Leipzig}, editor = {J{\"a}kel, Jens and Thiel, Robert}, publisher = {VDE-Verlag}, isbn = {978-3-8007-5180-8}, pages = {7}, language = {de} } @article{Roesel, author = {R{\"o}sel, Birgit}, title = {Just-in-Time Teaching f{\"u}r einen Grundkurs Regelungstechnik - Ergebnisse und Auswirkungen der Profistufe des Zertifikats Hochschullehre}, series = {Didaktiknachrichten}, journal = {Didaktiknachrichten}, number = {06}, publisher = {Zentrum f{\"u}r Hochschuldidaktik (DiZ)}, pages = {66 -- 71}, language = {de} } @article{EmbergerAltmannGebhardetal., author = {Emberger, Peter and Altmann, Robert and Gebhard, J{\"u}rgen and Thuneke, Klaus and Winkler, Markus and T{\"o}pfer, Georg and Rabl, Hans-Peter and Remmele, Edgar}, title = {Combustion characteristics of pure rapeseed oil fuel after injection in a constant volume combustion chamber with a non-road mobile machinery engine solenoid injector}, series = {Fuel}, journal = {Fuel}, number = {320}, publisher = {Elsevier}, doi = {10.1016/j.fuel.2022.123979}, abstract = {Pure rapeseed oil fuel (R100) according to standard DIN 51605 is a greenhouse gas saving option for the mobility sector. With its high energy density close to diesel fuel, R100 is suitable to operate non-road mobile machinery with a high power demand and long operating time, where electric drives reach their limits. Advantages are indicated for its use in environmentally sensitive areas like agriculture since R100 is highly biodegradable and non-toxic. However, R100 is characterised by differing physical and chemical properties compared to diesel. The objective of the research is to investigate the differences in the ignition and combustion behaviour of R100 compared to diesel fuel (DF). For this purpose, a constant volume combustion chamber is used, which is equipped with a modern solenoid injector for engines of non-road mobile machinery. The researched injector shows a different hydraulic behaviour when using R100 compared to DF in that the injected fuel mass is lower with R100 than with DF. In combination with the 14 \% by mass lower calorific value, less energy output is determined with R100. When varying the injection pressure, the impact on the ignition delay and combustion behaviour is much higher for R100 than for DF. Specifically, an increase of the injection pressure supports mixture preparation and thus partially compensates the differing physical properties of R100. The results of ignition delay measurements and net heat release analysis are as follows: At low load conditions with low injection pressure as well as a low combustion chamber temperature and pressure, R100 ignites later and shows a further delayed combustion compared to diesel. The opposite is observed for medium and high load conditions, where R100 ignites faster and without delayed combustion in comparison to DF. Thus, an adjustment of the heat release of R100 at the same level as for DF is possible by modifying the injection strategy. The research shows that for an optimised combustion of R100 the injection settings must be adjusted for every operation point separately. The results indicate how the injection parameters should be adjusted for different load conditions to realise a high-quality engine calibration for R100.}, language = {en} } @incollection{MuehlbauerRablRottengruber, author = {M{\"u}hlbauer, Christian and Rabl, Hans-Peter and Rottengruber, Hermann}, title = {Acoustic Optimization of Mechatronic Direct Injection Systems and Analysis of the Effects on Robustness in System Operation}, series = {SAE International Journal of Advances and Current Practices in Mobility}, volume = {4}, booktitle = {SAE International Journal of Advances and Current Practices in Mobility}, number = {1}, publisher = {SAE International, Warrendale, PA, United States}, issn = {2641-9645}, doi = {10.4271/2021-01-0671}, pages = {68 -- 77}, abstract = {The tightening of the emission legislation and political and social demands for sustainable mobility are forcing the automotive industry to develop complex, high precision mechatronic drive systems. The increasing precision of mechatronic components generally leads to an increase in structural excitation and thus to a rise in noise. The so-called ticking of the fuel injection system has a rather low sound pressure level compared to the residual engine noise. Nevertheless, the impulsive and high frequency noise character leads to a decline concerning the perception of comfort and sound quality. In order to identify the sound quality of fuel injection systems as a frontloading measure, a system test bench has been developed which represents the structure-borne and airborne sound radiation of the stand-alone injection system in a close to series configuration. In this paper, measures for the acoustic optimization of injection systems and their effects on the robustness of the system are discussed. The focus is on engine idling, since at this operating point the ticking of the injectors and high-pressure pump can be perceived most clearly due to the low masking effects of other noise sources. For this purpose, the injection parameters were measured during full engine operation and transferred to the system test bench. By using a special development control unit, it was possible to modify the parameters, quantify their influence on the acoustic behavior and, based on this, define NVH optimized control strategies. For the robustness evaluation of the NVH optimized control strategies, key functions of the injection system were analyzed under varying boundary conditions in system operation on an injection rate test bench.}, language = {en} } @misc{SchwanzerMieslingerRabletal., author = {Schwanzer, Peter and Mieslinger, Johann and Rabl, Hans-Peter and Dietrich, Markus and Haft, Gerhard and Walter, Stefanie and Hagen, Gunter and Moos, Ralf and Gaderer, Matthias}, title = {Monitoring of a Particulate Filter for Gasoline Direct Injection Engines with a Radio-Frequency-Sensor}, series = {11th International Exhaust Gas and Particulate Emissions Forum, 3.-4.3.2020, Ludwigsburg, Germany}, journal = {11th International Exhaust Gas and Particulate Emissions Forum, 3.-4.3.2020, Ludwigsburg, Germany}, abstract = {In order to comply with future emission regulations, the use of particulate filters in vehicles with direct injection gasoline engines is essential. The current amount of soot and ash in the filter is calculated by a soot load model in the electronic control unit in combination with a differential pressure sensor determining the pressure drop over the particulate filter. Active regeneration is initiated if the calculated amount of soot or the measured differential pressure is too high. This is associated with additional fuel consumption. An on-board diagnosis for the particulate filter is currently not part of the Euro 6d emission standard. For future exhaust emission standards, on-board diagnosis or active monitoring of the particulate filter is conceivable. One of the benefits of monitoring is the fact that unnecessary active regenerations can be avoided. As a result, there is no additional fuel consumption due to misinterpretations of the amount of soot in the filter. For active monitoring of the particulate filter, a radiofrequency (RF-) sensor, that detects the soot loading of the filter with electromagnetic waves directly, can be used. Such a system has the advantage that by utilizing the filter as a sensor more precise information about the current state of the filter, e.g. a possible damage, can be provided. Worst-case considerations of filter damages, tested at an engine test bench show the advantages which are entailed by a system like that. By means of partial regeneration of the particulate filter it is demonstrated how the remaining amount of soot in the filter can be detected in a better way in comparison to the differential pressure sensor by using the RF-sensor.}, language = {en} } @article{BrockKoderRabletal., author = {Brock, Damian and Koder, Alexander and Rabl, Hans-Peter and Touraud, Didier and Kunz, Werner}, title = {Optimising the biodiesel production process: Implementation of glycerol derivatives into biofuel formulations and their potential to form hydrofuels}, series = {Fuel}, volume = {264}, journal = {Fuel}, number = {March}, publisher = {Elsevier}, doi = {10.1016/j.fuel.2019.116695}, abstract = {A new biofuel concept is developed, enabling the usage of vegetable oils and glycerol derivatives in mixtures with biodiesel. This concept significantly enhances the biodiesel production's profitability and thus strongly contributes to the sustainability of future biofuels. After simple addition reactions with building block chemicals, less hydrophilic glycerol derivatives are obtained, which are compatible with biofuels. Even more, the products of the reactions of glycerol with acetone or butyric acid, referred to as solketal and tributyrin, respectively, lead to promising biofuels in mixtures with rapeseed oil and its biodiesel. Due to their low freezing points, they act as cloud and freezing point depressants, when added to vegetable oil/biodiesel blends. Further, since their viscosity is close to common biodiesel, biofuels containing high amounts of vegetable oil and even more glycerol derivatives than they arise during the biodiesel production can be obtained. Thus, this new class of biofuels enables adaptable compositions depending on the application and also the usage as drop-in fuel without any or just few percent of further additives. After optimising the formulations, ignition delay, exhaust gas recirculation, fuel consumption and combustion process measurements were performed in an unmodified upto-date diesel engine. The experiments showed that the properties of the formulated biofuels are either similar to or even better than diesel. The hydrotropy of the glycerol derivatives in these mixtures enables the potential to implement water into biofuels, so-called hydrofuels, reducing nitrogen oxide emissions and leading to further optimised dropin fuels.}, language = {en} } @incollection{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Haft, Gerhard and Dietrich, Markus and Rabl, Hans-Peter and Moos, Ralf}, title = {Hochfrequenzsensorik zur direkten Beladungserkennung von Benzinpartikelfiltern}, series = {Automobil-Sensorik 3}, booktitle = {Automobil-Sensorik 3}, editor = {Tille, Thomas}, publisher = {Springer Vieweg}, address = {Berlin}, isbn = {978-3-662-61259-0}, doi = {10.1007/978-3-662-61260-6_7}, pages = {185 -- 208}, abstract = {In Folge der Versch{\"a}rfung der gesetzlichen Abgasnormen wurden f{\"u}r direkt-einspritzende Benzinmotoren Partikelfilter notwendig. Zur Beladungs{\"u}berwachung k{\"o}nnen aufgrund stark unterschiedlicher Rahmenbedingungen die aus Dieselmotoren bekannten Systeme, wie dem Differenzdrucksensor, nur eingeschr{\"a}nkt {\"u}bernommen werden. Ein hochfrequenzbasiertes Verfahren koppelt mittels Antennen elektromagnetische Wellen in das Filtergeh{\"a}use ein, deren Ausbreitungsverhalten durch die dielektrischen Eigenschaften des eingelagerten Rußes beeinflusst wird. Hierdurch kann bei Auswertung von Transmissionsd{\"a}mpfung oder Resonanzfrequenzen die Rußbeladung direkt detektiert werden.}, language = {en} } @inproceedings{GrothmannPoelsterlGerling, author = {Grothmann, Benjamin and Poelsterl, Thomas and Gerling, Dieter}, title = {Online compensation of current sensor gain-faults for safety-relevant IPM-drives}, series = {2017 IEEE Transportation Electrification Conference and Expo (ITEC), 22-24 June 2017, Chicago, IL, USA}, booktitle = {2017 IEEE Transportation Electrification Conference and Expo (ITEC), 22-24 June 2017, Chicago, IL, USA}, publisher = {IEEE}, doi = {10.1109/ITEC.2017.7993355}, pages = {701 -- 706}, abstract = {Detection and compensation of current sensor gain-faults regardless of the operating-point is a crucial aspect for safety-relevant servo-drives. This paper presents and investigates a new direct phase-gain re-balancing methodology, especially suited for interior permanent magnet machine (IPM) drives mostly operating at low speed-ranges including standstill. The proposed model-based approach utilizes high-frequency signal-injection (HFI) to facilitate fast and persistent sensor monitoring for any operating state of the drive. No additional sensing hardware is required. Extraction of the HFI-phase-current response enables detection and immediate compensation of sensor gain-faults. Implementation aspects of the proposed concept are discussed thoroughly. Experimental results are presented to prove and investigate robustness, reliability and fault-tolerant performance.}, language = {en} } @inproceedings{SchmidtFuchsFuchs, author = {Schmidt, Hans-Peter and Fuchs, Andreas and Fuchs, Stefan}, title = {Simultaneous contact less charging of multiple electric vehicles: Contact less power and data transfer for multiple distributed loads}, series = {2014 4th International Electric Drives Production Conference ( 30 Sept.-1 Oct. 2014, Nuremberg, Germany}, booktitle = {2014 4th International Electric Drives Production Conference ( 30 Sept.-1 Oct. 2014, Nuremberg, Germany}, publisher = {IEEE}, doi = {10.1109/EDPC.2014.6984435}, pages = {1 -- 3}, abstract = {A design of a 3-phase inductive power and data transfer for multiple stationary loads is proposed. It focuses on stable load voltages while minimizing electromagnetic interference. Loads are contactless charging units of electric vehicles at car parks. Physical properties of the inductive couplers are modelled via 3-D FEM and lumped parameters are used for system studies. Design principles are verified at laboratory scale with a purpose built test stand.}, language = {en} } @inproceedings{SchorrBoehmZentneretal., author = {Schorr, Philipp and B{\"o}hm, Valter and Zentner, Lena and Zimmermann, Klaus}, title = {Dynamical Investigation of Crawling Motion System based on a Multistable Tensegrity Structure}, series = {Proceedings of the 15th International Conference on Informatics in Control, Automation and Robotics : Porto, Portugal, 29.07.2018 - 31.07.2018}, booktitle = {Proceedings of the 15th International Conference on Informatics in Control, Automation and Robotics : Porto, Portugal, 29.07.2018 - 31.07.2018}, publisher = {SCITEPRESS}, isbn = {978-989-758-321-6}, doi = {10.5220/0006852701220130}, pages = {122 -- 130}, abstract = {The basic idea of this article is the utilization of the multistable character of a compliant tensegrity structure to control the direction of motion of a crawling motion system. A crawling motion system basing on a two-dimensional tensegrity structure with multiple stable equilibrium states is considered. This system is in contact with a horizontal plane due to gravity. For a selected harmonic actuation of the system small oscillations around the given equilibrium state of the tensegrity structure occur and the corresponding uniaxial motion of the system is evaluated. A change of the equilibrium state of the tensegrity structure yields to novel configuration of the entire system. Moreover, the motion behavior of the novel configuration is totally different although the actuation strategy is not varied. In particular, the direction of motion changes. Therefore, this approach enables a uniaxial bidirectional crawling motion with a controllable direction of motion using only one actuat or with a selected excitation frequency.}, language = {en} } @inproceedings{HofmannScharfenberg, author = {Hofmann, Gerhard and Scharfenberg, Georg}, title = {Applicability of the ISO 26262 for functional safety for motorbikes}, series = {2014 International Conference on Applied Electronics, 9-10 Sept. 2014, Pilsen, Czech Republic}, booktitle = {2014 International Conference on Applied Electronics, 9-10 Sept. 2014, Pilsen, Czech Republic}, publisher = {IEEE}, doi = {10.1109/AE.2014.7011679}, pages = {107 -- 112}, abstract = {This article deals with the question to what extent the automotive standard for functional safety ISO 26262 is also applicable to motorbikes. It examines thereby, on the one hand where to find comparable criteria between cars and motorbikes from the standpoint of functional safety, and, on the other hand, where differences between the automobile and the motorbike must be considered. It shows the extent to which the safety-related automotive standard is applicable to motorbikes. Furthermore, the differences are determined, which must lead to the consequence of a new "state of the art" and to a new standard for motorbikes. On the example of a light function the new MSIL classification gets applied. In this article, the motorbike is viewed as a whole. For the most parts the standard is also valid for scooters.}, language = {en} } @inproceedings{HaumerKral, author = {Haumer, Anton and Kral, Christian}, title = {Enhancements of Electric Machine Models: The EMachines Library}, series = {Proceedings of the 11th International Modelica Conference, Versailles, France, September 21-23, 2015}, volume = {118}, booktitle = {Proceedings of the 11th International Modelica Conference, Versailles, France, September 21-23, 2015}, publisher = {Link{\"o}ping University Electronic Press}, doi = {10.3384/ecp15118509}, pages = {509 -- 515}, abstract = {Transient models of multi phase electric machines are already implemented in the Modelica Standard Library (MSL). However, advanced effects like saturation and skin effect are not taken into account. As an extension to the MSL models, the new EMachines library is presented. This package will be released as a supplemental library to the commercial EDrives library. The particular focus of this paper is on the deep bar effect of induction machines. A comparison of simulation results demonstrates the influence of the skin effect on the operational behavior of the machines. At the end of this publication further developments of the EMachines library will be outlined.}, language = {en} } @inproceedings{BeckeSchlegl, author = {Becke, Mark and Schlegl, Thomas}, title = {Least squares pose estimation of cylinder axes from multiple views using contour line features}, series = {IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 9-12 Nov. 2015, Yokohama, Japan}, booktitle = {IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 9-12 Nov. 2015, Yokohama, Japan}, publisher = {IEEE}, doi = {10.1109/IECON.2015.7392371}, pages = {1855 -- 1861}, abstract = {In this paper, a new method for a minimum-error pose estimation of cylinder axes based on apparent contour line features from multiple views is presented. Novel model equations for both single and particularly multiple views are derived, and based upon these, an iterative algorithm for least squares fitting the model to imaged cylinder contour line features is introduced. The good performance and fast convergence of the proposed algorithm is shown by solving exemplary fitting problems.}, language = {en} } @inproceedings{RoeselKoehler, author = {R{\"o}sel, Birgit and K{\"o}hler, Thomas}, title = {First results of a new digitalized concept for teaching control theory as minor subject at a university of applied science}, series = {2018 IEEE Global Engineering Education Conference (EDUCON), 17-20 April 2018, Santa Cruz de Tenerife, Spain}, booktitle = {2018 IEEE Global Engineering Education Conference (EDUCON), 17-20 April 2018, Santa Cruz de Tenerife, Spain}, publisher = {IEEE}, doi = {10.1109/EDUCON.2018.8363217}, pages = {118 -- 125}, abstract = {This paper presents a digitalized concept for teaching control theory as minor subject with an integrated approach for lectures, exercises and practical sessions and first results of the implementation at the department of electrical engineering at the OTH Regensburg. The concept uses activating methods like blended learning and possibilities of digitalization of teaching implementing Just in Time Teaching and Peer Instruction. The base of the new concept is the idea of constructive alignment. Furthermore this paper presents the feedback of the students along with an accompanying scientific research over several semesters. The data obtained from the presented module are compared with the data from other blended learning approaches in Germany.}, language = {en} } @inproceedings{Schiek, author = {Schiek, Roland}, title = {Self-phase modulation in lithium niobate waveguides}, series = {2014 International Conference Laser Optics, title=Self-phase modulation in lithium niobate waveguides, 30 June-4 July 2014, St. Petersburg, Russia}, booktitle = {2014 International Conference Laser Optics, title=Self-phase modulation in lithium niobate waveguides, 30 June-4 July 2014, St. Petersburg, Russia}, publisher = {IEEE}, doi = {10.1109/LO.2014.6886403}, abstract = {Self-phase modulation in lithium niobate wave-guides with cascaded quadratic and cubic nonlinearities is characterized by comparison of amplitude and phase of input and output pulse envelopes and spectra. Cubic nonlinear susceptibility coefficients of lithium niobate were determined from the measured nonlinear phase shifts.}, language = {en} } @inproceedings{DessortChucholowskiRill, author = {Dessort, Ronnie and Chucholowski, Cornelius and Rill, Georg}, title = {Parametrical approach for modeling of tire forces and torques in TMeasy 5}, series = {16. Internationales Stuttgarter Symposium, Automobil- und Motorentechnik, Bd. 1}, booktitle = {16. Internationales Stuttgarter Symposium, Automobil- und Motorentechnik, Bd. 1}, editor = {Bargende, Michael and Reuss, Hans-Christian and Wiedemann, Jochen}, publisher = {Springer}, address = {Wiesbaden}, isbn = {978-3-658-13254-5}, doi = {10.1007/978-3-658-13255-2_31}, pages = {435 -- 449}, abstract = {For the dynamic simulation of on-road vehicles, the model-element "tire/road" is of special importance, according to its influence on the achievable results. Sufficient description of the interaction between tire and road is one of the most challenging tasks of vehicle modeling. Two groups of tire models can be classified: handling models and structural or high-frequency models. Usually, various assumptions are made in modeling vehicles as multibody systems. Therefore, in the interest of balanced modeling, the precision of the complete vehicle model should stand in reasonable relation to the performance of the applied tire model. Handling tire models are characterized by a useful compromise between user friendliness, model complexity, and efficiency in computation time on the one hand, and precision in representation on the other hand.}, language = {en} } @inproceedings{HacklHirschbergLexetal., author = {Hackl, Andreas and Hirschberg, Wolfgang and Lex, Cornelia and Rill, Georg}, title = {Parameterization Process of the Maxwell Model to Describe the Transient Force Behavior of a Tire}, series = {WCX 17: SAE World Congress Experience 2017}, booktitle = {WCX 17: SAE World Congress Experience 2017}, publisher = {SAE}, doi = {10.4271/2017-01-1505}, abstract = {The present technical article deals with the modeling of dynamic tire forces, which are relevant during interactions of safety relevant Advanced Driver Assistance Systems (ADAS). Special attention has been paid on simple but effective tire modeling of semi-physical type. In previous investigations, experimental validation showed that the well-known first-order Kelvin-Voigt model, described by a spring and damper element, describes good suitability around fixed operation points, but is limited for a wide working range. When aiming to run vehicle dynamics models within a frequency band of excitation up to 8 Hz, these models deliver remarkable deviations from measured tire characteristics. To overcome this limitation, a nonlinear Maxwell spring-damper element was introduced which is qualified to model the dynamic hardening of the elastomer materials of the tire. However, the advantage of a more realistic description of the transient behavior leads to a more complex parametrization process. Therefore, in the proposed article attention is paid to describe the identification process including defined maneuvers to parameterize the tire model, where the accuracy of the parameter strongly depends on the quality of the available input data from measurement. In order to study this important aspect of parameterization, the reference data from simulation of the full physical tire model FTire is applied like a "virtual measurement" of specified testing maneuvers. The procedure of simulation by means of the enhanced first order dynamics model is implemented by the semi-physical tire model TMeasy. Finally, the improvements of the extended model are discussed and an outlook for future work is given.}, language = {en} } @inproceedings{CroceDiamantidisSykora, author = {Croce, Valeria and Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Planning post earthquake surveys: assessments and reconstruction of small historical centres}, series = {1st IABSE Online Symposium 2020, Synergy of culture and civil engineering - history and challenges: Wrocław, Poland, 7-9 October 2020, Proceedings}, booktitle = {1st IABSE Online Symposium 2020, Synergy of culture and civil engineering - history and challenges: Wrocław, Poland, 7-9 October 2020, Proceedings}, editor = {Bien, Jan}, publisher = {Curran Associates Inc}, address = {Red Hook, NY}, isbn = {978-1-7138-2387-2}, pages = {332 -- 339}, abstract = {The contribution presents a methodological procedure for the management and planning of interventions after earthquake events in small historic centres. Reference is made to the case study of Castelluccio di Norcia, a village in the Apennine Mountains affected by the seismic sequence that hit Central Italy in 2016. The earthquake risk of the area and the damaging events of 2016 are critically reviewed. The implementation of cognitive analysis and the application of advanced survey techniques involving the use of nmanned Aerial Vehicles (UAVs) for the purposes of emergency management and monitoring of damaged areas are analysed. The outcomes, combined with the direct involvement of the local population, represent a complete and integrated approach allowing the definition of a) possible intervention strategies, b) related decision criteria and c) practical recommendations for the reconstruction and regeneration of Castelluccio, and, in general, of small historic centres damaged by catastrophic events.}, language = {en} } @inproceedings{Roesel, author = {R{\"o}sel, Birgit}, title = {A concept of a mainly digitalized course on control theory including problembased practical units and digital supported exams}, series = {HEAd'20: Sixth International Conference on Higher Education Advances, June 2 - June 5 2020, Valencia (Spain)}, booktitle = {HEAd'20: Sixth International Conference on Higher Education Advances, June 2 - June 5 2020, Valencia (Spain)}, doi = {10.4995/HEAd20.2020.11112}, abstract = {This paper decribes the concept of a course on control theory as a minor subject in the department of electrical engineering at the OTH Regensburg. The basis for a new concept is the idea of contructive alignment. The whole teaching module is devided in two blocks. The first block contains the teaching of the knowledge about control theory with an integrated approach for lectures, exercises and practical sessions. In the second block the students attent a practical work package to have the possibility to applicate and deepen their knowledge. To foster active participation the students are asked to document and reflect their work with the course context in an electronic portfolio. The exam of this module consists of three parts with respect to the different competencies obtained during the module. This concept develops not only the knowledge on control theory but personal and social competencies which are of growing interest. The aim of the paper is to present the idea of the concept. Following papers will illustrate the development process and the results obtained later on.}, language = {en} } @inproceedings{DiamantidisSykora, author = {Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Reliability Differentiation and Uniform Risk in Standards}, series = {Scientific Symposium Future Trends in Civil Engineering, Zagreb,Croatia, 17 October 2029}, booktitle = {Scientific Symposium Future Trends in Civil Engineering, Zagreb,Croatia, 17 October 2029}, doi = {10.5592/CO/FTCE.2019.11}, pages = {241 -- 260}, abstract = {Reliability of structures and infrastructures is a major issue in structural engineering. Structural standards have traditionally been mainly concerned with public safety preventing loss of life or injury; this view has been shifting in recent years towards minimisation of economic loss. This contribution discusses the reliability differentiation principle in modern standards. Its aim is to achieve uniform risk levels for the various classes of structures. Codified criteria for reliability differentiation and risk informed decisions inherent in standards and especially in the Eurocodes are critically reviewed. It is shown that the classification of structures based on consequences of failure is an approach that has not been widely implemented in everyday design. Practical rules for the classification and implementation in design are needed and related proposals are presented.}, language = {en} } @article{FrazzicaPalombaDawoud, author = {Frazzica, Andrea and Palomba, Valeria and Dawoud, Belal}, title = {Thermodynamic Performance of Adsorption Working Pairs for Low-Temperature Waste Heat Upgrading in Industrial Applications}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {8}, publisher = {MDPI}, doi = {10.3390/app11083389}, abstract = {The present work aims at the thermodynamic analysis of different working pairs in adsorption heat transformers (AdHT) for low-temperature waste heat upgrade in industrial processes. Two different AdHT configurations have been simulated, namely with and without heat recovery between the adsorbent beds. Ten working pairs, employing different adsorbent materials and four different refrigerants, have been compared at varying working boundary conditions. The effects of heat recovery and the presence of a temperature gradient for heat transfer between sinks/sources and the AdHT components have been analyzed. The achieved results demonstrate the possibility of increasing the overall performance when internal heat recovery is implemented. They also highlight the relevant role played by the existing temperature gradient between heat transfer fluids and components, that strongly affect the real operating cycle of the AdHT and thus its expected performance. Both extremely low, i.e., 40-50 degrees C, and low (i.e., 80 degrees C) waste heat source temperatures were investigated at variable ambient temperatures, evaluating the achievable COP and specific energy. The main results demonstrate that optimal performance can be achieved when 40-50 K of temperature difference between waste heat source and ambient temperature are guaranteed. Furthermore, composite sorbents demonstrated to be the most promising adsorbent materials for this application, given their high sorption capacity compared to pure adsorbents, which is reflected in much higher achievable specific energy.}, language = {en} } @inproceedings{AltmannGebhardTroegeretal., author = {Altmann, Robert and Gebhard, J{\"u}rgen and Troeger, Adrian and Winkler, Markus and T{\"o}pfer, Georg and Remmele, Edgar and Gaderer, Matthias and Rabl, Hans-Peter}, title = {Engine performance and emission analysis of a NRMM CI engine with common rail injection system operated with diesel fuel and rapeseed oil fuel}, series = {Proceedings of the 6th Commercial Vehicle Technology Symposium 2020/2021}, booktitle = {Proceedings of the 6th Commercial Vehicle Technology Symposium 2020/2021}, editor = {Berns, Karsten and Dressler, Klaus and Kalmar, Ralf and Stephan, Nicole and Teutsch, Roman and Thul, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-29716-9}, doi = {10.1007/978-3-658-29717-6_16}, pages = {231 -- 242}, abstract = {The use of alternative fuels in high-power non-road mobile machinery (NRMM) combustion engines is a possible way to substitute fossil fuel. By using pure vegetable oil fuels, like rapeseed oil fuel (DIN 51605), the greenhouse gases can be reduced effectively. Due to the differences in physical and chemical properties, a modification of the engine control unit calibration is necessary to adapt the working process on the fuel. Without modifications, the engine power output with rapeseed oil fuel is lower than with diesel fuel because of the smaller energy content. By adapting the engine settings, like the injection fuel mass, the power loss can be compensated but it accompanies with a higher fuel consumption. The engine emissions at part load conditions show, that there are benefits in particle emissions by using rapeseed oil at similar NOx emissions. Therefore, a design of experiment setup was initiated on a selected engine operation point to determine the effects of further parameters, like rail pressure, manifold pressure and injection pattern, on the process and to see the potential of an optimized calibration.}, language = {en} } @inproceedings{RillArrietaCastro, author = {Rill, Georg and Arrieta Castro, Abel}, title = {A Novel Approach for Parametrization of Suspension Kinematics}, series = {Advances in Dynamics of Vehicles on Roads and Tracks: Proceedings of the 26th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2019), August 12-16, 2019, Gothenburg, Sweden}, booktitle = {Advances in Dynamics of Vehicles on Roads and Tracks: Proceedings of the 26th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2019), August 12-16, 2019, Gothenburg, Sweden}, editor = {Klomp, Matthijs and Bruzelius, Fredrik and Nielsen, Jens and Hillemyr, Angela}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-38076-2}, doi = {10.1007/978-3-030-38077-9_210}, pages = {1848 -- 1857}, abstract = {n the automotive industry, simulations are needed to analyse the dynamics of vehicles and also of its main components and subsystems, e.g. tires, brakes and suspension systems. These simulations are required for an early-stage development and in consequence, they must deliver realistic results. Suspension systems plays a key role in comfort and safety of road vehicles. They usually consist of rigid links and force elements that are arranged with a specific topology. In addition, some of their functionalities are to carry the weight of the car and the passengers, and maintain a correct wheel alignment. In simulations involving suspension systems, lookup-tables are frequently used. They are obtained from a Kinematic and Compliance (KnC) test and then standardized for a specific vehicle simulation software. Nonetheless, lookup-tables require a reasonable number of characteristic points. Additionally, derivatives, interpolation, and extrapolation are not necessarily smooth. This produces results that depend on the interpolation technique and may be inaccurate. In this paper, a novel method called "design kinematics" is proposed. This method can describe the kinematic properties of almost any type of suspension systems. Comparisons with an analytic calculation and a KnC measurement shown that the design kinematics is able to represent the kinematic and compliance properties of suspension systems extremely well and very efficiently.}, language = {en} } @inproceedings{RillArrietaCastro, author = {Rill, Georg and Arrieta Castro, Abel}, title = {The Influence of Axle Kinematics on Vehicle Dynamics}, series = {Interdisciplinary Applications of Kinematics. Proceedings of the Third International Conference (IAK)}, volume = {71}, booktitle = {Interdisciplinary Applications of Kinematics. Proceedings of the Third International Conference (IAK)}, editor = {Kecskem{\´e}thy, Andr{\´e}s and Geu Flores, Francisco and Carrera, Eliodoro and Elias, Dante A.}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-16422-5}, doi = {10.1007/978-3-030-16423-2_2}, pages = {23 -- 31}, abstract = {The automotive industry employs many different kinds of axle suspension systems at modern passenger cars. Important criteria are costs, space requirements, kinematic properties, and compliance attributes. This paper illustrates that in particular the kinematic properties of a suspension system have a significant influence on the dynamics of vehicles. As a consequence, the kinematics of a suspension system must be modeled very precisely and nonlinear. Typical kinematical features of a suspension system are discussed by analyzing the most common double wishbone axle suspension system. The influence of the axle kinematics on vehicle dynamics is finally demonstrated by simulation results generated with a fully nonlinear and three-dimensional multibody vehicle model.}, language = {en} } @incollection{Rill, author = {Rill, Georg}, title = {Multibody Systems and Simulation Techniques}, series = {Vehicle Dynamics of Modern Passenger Cars}, booktitle = {Vehicle Dynamics of Modern Passenger Cars}, editor = {Lugner, Peter}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-319-79007-7}, doi = {10.1007/978-3-319-79008-4_6}, pages = {309 -- 375}, abstract = {This part begins with an introduction to Multibody Systems (MBS). It presents the elements of MBS and discusses different modeling aspects. Then, different methods to generate the equations of motion are presented. Solvers for ordinary differential equations (ODE) as well as differential algebraic equations (DAE) are discussed. Finally, techniques for "online" and "offline" simulations including real-time applications are presented like necessary for car development. Special examples show the connection between simulation and test results.}, language = {en} } @inproceedings{ThomeczekAttenbergerKolbetal., author = {Thomeczek, Ludwig and Attenberger, Andreas and Kolb, Johannes and Matoušek, V{\´a}clav and Mottok, J{\"u}rgen}, title = {Betrachtungen zu Latenzquellen und deren Beobachtung in POSIX-Systemen am Beispiel von Container-Runtimes}, series = {Echtzeit 2019}, volume = {35}, booktitle = {Echtzeit 2019}, editor = {Unger, Herwig}, publisher = {Springer Fachmedien Wiesbaden}, address = {Wiesbaden}, isbn = {978-3-658-27807-6}, doi = {10.1007/978-3-658-27808-3_12}, pages = {109 -- 118}, abstract = {Die am weitesten verbreiteten autonomen Systeme der Zukunft sind aller Voraussicht nach intelligente Fahrzeuge, welche selbst{\"a}ndig im Straßenverkehr navigieren und mit der Umgebung interagieren. Diese neuen Funktionen erfordern den Einsatz von performanten Mehrkernprozessoren sowie von komplexen (POSIX-kompatiblen) Betriebssystemen. Gleichzeitig erfordert der Einsatz im Automobil hohe funktionale Sicherheit (ASIL-Level), was unter anderem robuste Echtzeiteigenschaften der verwendeten Hard- und Software voraussetzt. Den Echtzeiteigenschaften steht die erh{\"o}hte Komplexit{\"a}t mit neuen Quellen f{\"u}r nichtdeterministische Latenzen gegen{\"u}ber. In diesem Paper pr{\"a}sentieren wir eine {\"U}bersicht {\"u}ber diese neuen Einflussfaktoren, und vermessen anschließend Containerlaufzeitumgebungen und deren Latenzverhalten. Wir zeigen dabei, das Netzwerkbr{\"u}cken unter Last erheblichen Einfluss (Faktor 4-5) auf die Netzwerklatenz aus{\"u}ben k{\"o}nnen.}, language = {de} } @article{SykoraDiamantidisHolickyetal., author = {S{\´y}kora, Miroslav and Diamantidis, Dimitris and Holick{\´y}, Milan and Markov{\´a}, Jana and R{\´o}zs{\´a}s, {\´A}rp{\´a}d}, title = {Assessment of compressive strength of historic masonry using non-destructive and destructive techniques}, series = {Construction and Building Materials}, volume = {193}, journal = {Construction and Building Materials}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.conbuildmat.2018.10.180}, pages = {196 -- 210}, abstract = {Masonry structures were built by various techniques using different materials, the properties of which exhibit a considerable scatter dependent on periods of construction and region-specific conditions. For historic structures with a heritage value, various non- or minor-destructive tests (NDTs) are commonly applied, while the application of destructive tests (DTs) is minimized. The contribution is based on investigations of 15 historic stone and clay brick masonry structures, for which NDT strengths of masonry units are verified by DTs. The proposed operational approach makes it possible to account for statistical uncertainty due to a limited number of DTs used to calibrate NDTs.}, language = {en} } @book{RillArrietaCastro, author = {Rill, Georg and Arrieta Castro, Abel}, title = {Road Vehicle Dynamics}, publisher = {CRC Press}, address = {Boca Raton, Fla.}, isbn = {9780429244476}, doi = {10.1201/9780429244476}, abstract = {Road Vehicle Dynamics: Fundamentals and Modeling with MATLAB®, Second Edition combines coverage of vehicle dynamics concepts with MATLAB v9.4 programming routines and results, along with examples and numerous chapter exercises. Improved and updated, the revised text offers new coverage of active safety systems, rear wheel steering, race car suspension systems, airsprings, four-wheel drive, mechatronics, and other topics. Based on the lead author's extensive lectures, classes, and research activities, this unique text provides readers with insights into the computer-based modeling of automobiles and other ground vehicles. Instructor resources, including problem solutions, are available from the publisher.}, subject = {Fahrdynamik}, language = {en} } @article{DechantFedulovChashinetal., author = {Dechant, Eduard and Fedulov, Feodor and Chashin, Dmitri V. and Fetisov, Leonid Y. and Fetisov, Yuri K. and Shamonin (Chamonine), Mikhail}, title = {Low-frequency, broadband vibration energy harvester using coupled oscillators and frequency up-conversion by mechanical stoppers}, series = {Smart Materials and Structures}, volume = {26}, journal = {Smart Materials and Structures}, number = {6}, publisher = {IOP Publishing}, doi = {10.1088/1361-665X/aa6e92}, abstract = {The frequencies of ambient vibrations are often low (below 30 Hz). A broadband (3 dB bandwidth is larger than 10 Hz at an acceleration amplitude of 9.81 m s(-2)) vibration based energy harvester is proposed for transducing mechanical energy at such low frequencies into electrical energy. The mechanical setup converts low frequency mechanical vibrations into high frequency resonance oscillations of the transducer. This conversion is done by mechanical impacts on two mechanical stoppers. The originality of the presented design is that both low-frequency and high-frequency oscillators are permanently mechanically coupled. In the equivalent mechanical circuit, this coupling is achieved by connecting the ends of the stiff spring to both seismic masses, whereas one seismic mass (collison member) is also attached to the soft spring used as the constitutive element of a low-frequency oscillator. Further, both mechanical oscillators are not realized as conventional cantilever beams. In particular, the high frequency oscillator with the natural frequency of 340 Hz is a disc-shaped diaphragm with attached piezoelectric elements and a seismic mass. It is shown that it is possible to convert mechanical vibrations with acceleration amplitude of 9.81 m s(-2) in the region between approximately 7 and 25 Hz into electrical power larger than 0.1 mW with the maximum value of 0.8 mW. A simplified mathematical model based on piecewise linear coupled oscillators shows good agreement with experimental results. The ways to enhance the performance of the harvester and improve agreement with experiments are discussed.}, language = {en} } @article{KasparRablMayer, author = {Kaspar, Marcel and Rabl, Hans-Peter and Mayer, Wolfgang}, title = {Ion-Molecule Reaction for the Selective Detection of Hydrocarbons in Diesel Exhaust Gas}, series = {Chemie Ingenieur Technik}, volume = {90}, journal = {Chemie Ingenieur Technik}, number = {6}, publisher = {WILEY-VCH}, doi = {10.1002/cite.201700075}, pages = {826 -- 834}, abstract = {The hydrocarbons present in the diesel exhaust gas are analyzed. A mass spectrometer is used for the measurements, and it operates on the basis of an ion-molecule reaction. This method is especially suitable because it is selective, is as free of fragments as possible, and is highly sensitive to the species that need to be measured. The study shows that numerous hydrocarbons in diesel exhaust gas can be identified. In particular, three molecules, ethyne, ethene and propene, were analyzed online in-depth on an engine test bench under different engine operating conditions.}, language = {en} } @article{SchorrBoehmZentneretal., author = {Schorr, Philipp and B{\"o}hm, Valter and Zentner, Lena and Zimmermann, Klaus}, title = {Motion characteristics of a vibration driven mobile tensegrity structure with multiple stable equilibrium states}, series = {Journal of Sound and Vibration}, volume = {437}, journal = {Journal of Sound and Vibration}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.jsv.2018.09.019}, pages = {198 -- 208}, abstract = {A novel type of a vibration driven motion system based on a compliant tensegrity structure with multiple stable equilibrium states is considered. These equilibrium configurations correspond to different prestress states with different dynamical properties. Therefore, the motion characteristics can be varied by changing the equilibrium state. For the application in the fields of mobile robotics, these discrete adjustable dynamics are advantageous. The vibration modes of the structure as well as the corresponding motion characteristics of the system can be adapted to the given environmental conditions in order to ensure a reliable motion. In this paper, dynamical investigations of an exemplary two-dimensional multistable tensegrity structure are considered. For the chosen parameter values the structure features two relevant equilibrium configurations. The resulting motion system is in contact to a horizontal plane due to gravity and the actuation is realized by the harmonic variation of the length of a single tensioned member. The motion of the system is simulated for various actuation frequencies with the different equilibrium states as an initial configuration. A uniaxial or a planar movement occurs depending on the selection of the actuated member within the tensegrity structure. The steady state motion is evaluated regarding motion characteristics like the steady state velocity. Moreover, the influences on the motion behavior caused by the different equilibrium states as an initial condition are emphasized. (C) 2018 Elsevier Ltd. All rights reserved.}, language = {en} } @article{SorokinStepanovShamoninChamonineetal., author = {Sorokin, Vladislav V. and Stepanov, Gennady V. and Shamonin (Chamonine), Mikhail and Monkman, Gareth J. and Kramarenko, Elena Yu}, title = {Magnetorheological behavior of magnetoactive elastomers filled with bimodal iron and magnetite particles}, series = {Smart materials and structures}, volume = {26}, journal = {Smart materials and structures}, number = {3}, publisher = {IOP Publishing}, doi = {10.1088/1361-665X/26/3/035019}, abstract = {Magnetoactive elastomers (MAE) based on soft silicone matrices, filled with various proportions of large diameter ( approximately 50 mu m) iron and small diameter ( approximately 0.5 mu m) magnetite particles are synthesized. Their rheological behavior in homogeneous magnetic fields up to 600 mT is studied in detail. The addition of small magnetite particles facilitates fabrication of uniformly distributed magnetic elastomer composites by preventing aggregation and sedimentation of large particles during curing. It is shown that using the proposed bimodal filler particles it is possible to tailor various magnetorheological (MR) properties which can be useful for different target applications. In particular, either absolute or relative magnetorheological effects can be tuned. The value of the damping factor as well as the range of deformation amplitudes for the linear viscoelastic regime can be chosen. The interdependencies between different MR properties of bimodal MAEs are considered. The results are discussed in the model framework of particle network formation under the simultaneous influence of external magnetic fields and mechanical deformation.}, language = {en} } @article{daSilvaMotaHinckelRoccoetal., author = {da Silva Mota, Fabio Antonio and Hinckel, Jose Nivaldo and Rocco, Evandro Marconi and Schlingloff, Hanfried}, title = {Modeling and Analysis of a LOX/Ethanol Liquid Rocket Engine}, series = {Journal of Aerospace Technology and Management}, volume = {10}, journal = {Journal of Aerospace Technology and Management}, publisher = {Inst Aeronautica \& Espaco-IAE}, doi = {10.5028/jatm.v10.914}, abstract = {This work studies the performance and dry mass of the under development LOX/Ethanol L75 liquid rocket engine. To this end, an object-oriented program written in C++ was developed. The program is intended to be versatile and easily extensible in order to analyze different configurations of liquid rocket engines. The UML (Unified Modeling Language) tool is used to model the architecture of the codes. UML diagrams help to visualize the code structure and the communication between objects, enabling a high degree of abstraction. The cryogenics Vulcain and HM7B engines power cycles along with the staged-combustion SSME engine perform the verification of the codes. Finally, the influence of changes in design parameters on the performance and dry mass of the L75 rocket engine is analyzed.}, language = {en} } @article{NiemetzHaenninenSchoepe, author = {Niemetz, Michael and H{\"a}nninen, Risto and Schoepe, Wilfried}, title = {On the Transition from Potential Flow to Turbulence Around a Microsphere Oscillating in Superfluid 4He}, series = {Journal of low temperature physics}, volume = {187}, journal = {Journal of low temperature physics}, number = {3-4}, publisher = {Springer Nature}, doi = {10.1007/s10909-017-1745-7}, pages = {195 -- 220}, abstract = {The flow of superfluid around a translationally oscillating sphere, levitating without mechanical support, can either be laminar or turbulent, depending on the velocity amplitude. Below a critical velocity that scales as and is temperature independent below 1 K, the flow is laminar (potential flow). Below 0.5 K, the linear drag force is caused by ballistic phonon scattering that vanishes as until background damping, measured in the empty cell, becomes dominant for K. Increasing the velocity amplitude above leads to a transition from potential flow to turbulence, where the large turbulent drag force varies as . In a small velocity interval \% above , the flow is unstable below 0.5 K, switching intermittently between both patterns. From time series recorded at constant temperature and driving force, the lifetimes of both phases are analyzed statistically. We observe metastable states of potential flow which, after a mean lifetime of 25 min, ultimately break down due to vorticity created by natural background radioactivity. The lifetimes of the turbulent phases have an exponential distribution, and the mean increases exponentially with . We investigate the frequency at which the vortex rings are shed from the sphere. Our results are compared with recent data of other authors on vortex shedding by moving a laser beam through a Bose-Einstein condensate. Finally, we show that our observed transition to turbulence belongs to the class of "supertransient chaos" where lifetimes of the turbulent states increase faster than exponentially.}, language = {en} } @article{PalombaDawoudSapienzaetal., author = {Palomba, Valeria and Dawoud, Belal and Sapienza, Alessio and Vasta, Salvatore and Frazzica, Andrea}, title = {On the impact of different management strategies on the performance of a two-bed activated carbon/ethanol refrigerator: An experimental study}, series = {Energy conversion and management}, volume = {142}, journal = {Energy conversion and management}, publisher = {Elsevier}, doi = {10.1016/j.enconman.2017.03.055}, pages = {322 -- 333}, abstract = {In the present work, an experimental study on a lab-scale adsorption refrigerator, based on activated carbon/ethanol working pair is reported. An extensive testing campaign has been carried out at the CNR ITAE laboratory, with multiple aims. First, the performance has been evaluated in terms of both COP and Specific Cooling Power (SCP), under different boundary conditions, including both air conditioning and refrigeration applications. Attractive SCPs, up to 180 W/kg and 70 W/kg for air conditioning and refrigeration, respectively, were measured. Under the same conditions, COP between 0.17 and 0.08 were obtained. In addition, different management strategies, namely, heat recovery between adsorbers and re-allocation of phase durations, were evaluated to identify their influence on the system. Both strategies confirmed the possibility of increasing COP and SCP up to 40\% and 25\%, respectively. Moreover, a design analysis based on the experimental results has been carried out, to suggest possible improvements of the system. The obtained results demonstrated the possibility of employing a non-toxic refrigerant like ethanol reaching performance comparable with other harmful refrigerants like ammonia and methanol. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{Dawoud, author = {Dawoud, Belal}, title = {On the development of an innovative gas-fired heating appliance based on a zeolite-water adsorption heat pump; system description and seasonal gas utilization efficiency}, series = {Applied Thermal Engineering}, volume = {72}, journal = {Applied Thermal Engineering}, number = {2}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2014.09.008}, pages = {323 -- 330}, abstract = {The main objective of this work is to introduce an innovative hybrid heating appliance incorporating a gas condensing boiler and a zeolite-water adsorption heat pump. The condensing boiler is applied to drive the zeolite-water heat pump for the heating base-load and to assist the heat pump in the so called "mixed operation" mode, in which both the heat pump and the condensing boiler are working in series to cover medium heating demands. Peak heating demands are covered by the condensing boiler in the so called "direct heating" mode. The three operation modes of the hybrid heating appliance have been technically described. In addition, the laboratory test conditions for estimating the seasonal heating performance according to the German Guideline VDI 4650-2 have been introduced. For both heating systems 35/28 °C and 55/45 °C, which represent the typical operating conditions of floor and high temperature radiating heating systems in Europe, seasonal heating gas utilization efficiencies of 1.34 and 1.26 have been measured, respectively with a ground heat source. In two field test installations in one-family houses in Germany, the introduced heating appliance showed 27\% more seasonal gas utilization efficiency for heating and domestic hot water production, which is equivalent to a CO2-emission reduction of 20\% compared to the gas condensing boiler technology.}, language = {en} } @article{Rill2017, author = {Rill, Georg}, title = {Reducing the cornering resistance by torque vectoring (X International Conference on Structural Dynamics, EURODYN 2017)}, series = {Procedia Engineering}, volume = {199}, journal = {Procedia Engineering}, publisher = {Elsevier}, doi = {10.1016/j.proeng.2017.09.393}, pages = {3284 -- 3289}, year = {2017}, abstract = {Usually, torque vectoring is used to reduce a significant understeer behavior at high speed cornering. Thus, providing larger vehicles with a sportive touch. Even on typical front wheel driven cars torque vectoring control is available now. Torque vectoring is nearly a standard on electric driven vehicles. Complex control and optimization strategies are applied to improve the maneuverability in particular or to enhance the driving behavior and reduce the energy consumption in addition. This paper shows, that a quite simple strategy will enhance the maneuverability and simultaneously reduce the cornering resistance in sharp bends. At first, a case study with a fully non-linear and three-dimensional vehicle model is performed. It turned out that a full drive torque shift to the outer wheels improves the maneuverability and reduces the cornering resistance in addition. This results are verified by an optimization performed with a simpler four-wheeled handling model. Here, the front steering angles and the driving torques at each of the four wheels are considered as free parameters. Minimizing the cornering resistance by taking the equations of motion for the four-wheeled handling model as constraints will deliver an optimal set of parameters then.}, language = {en} }