@inproceedings{ArrietaCastroChavesRilletal., author = {Arrieta Castro, Abel and Chaves, Rafael B. and Rill, Georg and Weber, Hans I.}, title = {Use of Integrated Control to Enhance the Safety of Vehicles in Run-Off-Road Scenarios}, series = {Proceedings of DINAME 2017 : Selected Papers of the XVII International Symposium on Dynamic Problems of Mechanics}, booktitle = {Proceedings of DINAME 2017 : Selected Papers of the XVII International Symposium on Dynamic Problems of Mechanics}, editor = {Fleury, Agenor de T. and Rade, Domingos A. and Kurka, R. G.}, edition = {1. Auflage}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-91217-2}, issn = {2195-4356}, doi = {10.1007/978-3-319-91217-2_30}, pages = {431 -- 443}, abstract = {In this work, an integrated vehicle control system (IC) is tested in run-off-road scenarios. The integrated approach was employed in order to coordinate vehicle control systems, i.e. the Anti-Lock Brake System (ABS), Four-wheel Steering (4WS) and the Electronic Stability Program (ESP). To perform a run-off-road maneuver, a fuzzy virtual test driver was designed. By receiving the lateral position of an obstacle and the vehicle's relative yaw angle, the virtual test driver is capable of following a reference trajectory. Furthermore, to test the performance of the standalone controllers, i.e. ABS, ESP and 4WS, individual maneuvers are performed using a multibody vehicle model. The vehicle without any coordination between the control systems is used as reference. For the simulation results, it is concluded that the IC improves the vehicle stability and maneuverability in comparison with the non-integrated approach.}, 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} } @inproceedings{HacklHirschbergLexetal., author = {Hackl, Andreas and Hirschberg, W. and Lex, C. and Rill, Georg}, title = {Tyre type dependent transient force behaviour by means of a maxwell model}, series = {The Dynamics of Vehicles on Roads and Tracks : Proceedings of the 25th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2017), Rockhampton, Queensland, Australia, 14-18 August 2017}, booktitle = {The Dynamics of Vehicles on Roads and Tracks : Proceedings of the 25th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2017), Rockhampton, Queensland, Australia, 14-18 August 2017}, editor = {Spiryagin, Maksym and Gordon, Timothy and Cole, Colin and McSweeney, Tim}, publisher = {CRC Press}, address = {London}, isbn = {1351057170}, doi = {10.1201/9781315265506}, pages = {157 -- 162}, abstract = {The present papers deals with the usability of an extended Maxwell model to describe the tyre dynamics during transient driving manoeuvres. In the present article, the para-metrisation process of a dynamic tyre model is investigated in a first step, using measurement data of tyre forces from a flat trac tyre test bench, (IABG 2016). Two tyre types of dimensions 255/50 R19 and 175/55 R15 are used. The practical applicability is discussed, considering the measurement procedure and the parameter optimisation process. In a second step, the performance of the dynamic tyre model is validated using measurements of manoeuvres under higher dynamic excitation. As a last step, an outlook is given on further research planned in which the presented model and parametrisation are adapted to a larger frequency range.}, language = {en} } @inproceedings{Rill, author = {Rill, Georg}, title = {Real-Time capable Multibody Model of dual Truck Front Axles}, series = {Proceedings of DINAME 2023 - Selected Papers of the XIX International Symposium on Dynamic Problems of Mechanics, 26 Feb - 03 Mar 2023, Piren{\´o}polis, Brazil}, booktitle = {Proceedings of DINAME 2023 - Selected Papers of the XIX International Symposium on Dynamic Problems of Mechanics, 26 Feb - 03 Mar 2023, Piren{\´o}polis, Brazil}, editor = {Fleury, Agenor de T.}, publisher = {Springer}, abstract = {Dual front steering axles are quite common in multi-axled heavy duty trucks. In standard layouts of such axle combinations, the steer motions of the wheels depend not only on the rotation of the steering wheel but also on the movements of the axles. As a consequence, the model complexity of the steering system should match with the complexity of the suspension model. The development of new technologies like advanced driver assistance systems or autonomous driving can only be accomplished efficiently using extensive simulation methods. Such kind of applications demand for computationally efficient vehicle models. This paper presents a steering system model for dual front axles of heavy duty trucks which supplements the suspension model of the axles. The model takes the torsional compliance of the steering column as well as the stiffness of the tie rods and the coupling rod into account. A quasi-static solution provides a straight forward computation including the partial derivatives required for an efficient implicit solver. The steering system model matches perfectly with comparatively lean, but sufficiently accurate multibody suspension models.}, language = {en} } @techreport{MichaelSternerMareikeJentschUweHolzhammer, author = {Michael Sterner, and Mareike Jentsch, and Uwe Holzhammer,}, title = {Energiewirtschaftliche und {\"o}kologische Bewertung eines Windgas-Angebotes}, publisher = {Fraunhofer Institute for Energy Economics and Energy System Technology}, address = {Kassel}, doi = {10.13140/RG.2.2.25093.68328}, abstract = {In this technical report, (1) the benefits of the new technology for future energy supply are discussed, (2) the climate protection effect of wind gas is discussed, and (3) a reasonable use of wind energy for gas generation is analyzed. In particular, windgas in the heat market is discussed in the utilization cascade of wind energy. The new "power-to-gas" concept opens up completely new possibilities for the integration of renewable energies and for coupling the electricity and gas grids. The Sabatier process, which has been known for 100 years, was first developed for this purpose in 2008 under the leadership of the Center for Solar Energy and Hydrogen Research and Fraunhofer IWES (formerly ISET) with electrolysis to create the "power-to-gas" concept for energy storage. A first pilot plant was built by ZSW Stuttgart on behalf of SolarFuel in 2009. This plant proves the technical feasibility of the new technology. Renewable gas is stored, transported and used as required as control and reserve energy via reconversion, e.g. in combined cycle power plants. In this way, decentrally generated renewable electricity is converted into a CO2 -neutral energy carrier with high energy density. The key advantage of renewable methane is the use of existing infrastructure such as gas grids, gas storage and end-use equipment for the integration of renewable energy. Technologies for natural gas are state of the art and commercially available. Methane also has three times the energy density of hydrogen.}, 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} } @article{SchuemannMorichKaufholdetal., author = {Sch{\"u}mann, Malte and Morich, J. and Kaufhold, T. and B{\"o}hm, Valter and Zimmermann, Klaus and Odenbach, Stefan}, title = {A mechanical characterisation on multiple timescales of electroconductive magnetorheological elastomers}, series = {Magnetism and Magnetic Materials}, volume = {453}, journal = {Magnetism and Magnetic Materials}, number = {May}, publisher = {Elsevier}, doi = {10.1016/j.jmmm.2018.01.029}, pages = {198 -- 205}, abstract = {Magnetorheological elastomers are a type of smart hybrid material which combines elastic properties of a soft elastomer matrix with magnetic properties of magnetic micro particles. This leads to a material with magnetically controllable mechanical properties of which the magnetorheological effect is the best known. The addition of electroconductive particles to the polymer mix adds electrical properties to the material behaviour. The resulting electrical resistance of the sample can be manipulated by external magnetic fields and mechanical loads. This results in a distinct interplay of mechanical, electrical and magnetic effects with a highly complex time behaviour. In this paper a mechanical characterisation on multiple time scales was conducted to get an insight on the short and long-term electrical and mechanical behaviour of this novel material. The results show a complex resistivity behaviour on several timescales, sensitive to magnetic fields and strain velocity. The observed material exhibits fatigue and relaxation behaviour, whereas the magnetorheological effect appears not to interfere with the piezoresistive properties.}, language = {en} } @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} } @misc{OPUS4-6542, title = {Energieforschung}, edition = {Ausgabe 2023}, publisher = {OTH Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg / Regensburg Center of Energy and Resources (RCER)}, doi = {10.35096/othr/pub-6542}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-65422}, abstract = {{\"U}ber uns Das Regensburg Center of Energy and Resources (RCER) b{\"u}ndelt seit 2012 die Aktivit{\"a}ten der Ostbayerischen Technischen Hochschule Regensburg (OTH Regensburg) und der regionalen Wirtschaftsunternehmen auf dem Strategiefeld „Energie und Ressourcen". Mission: Energieforschung: vernetzen, voranbringen, vermitteln Das RCER f{\"o}rdert die Vernetzung verschiedener Disziplinen der Energieforschung innerhalb der OTH Regensburg und mit externen Partnern (Firmen, F{\"o}rdertr{\"a}gern, Forschungsinstitutionen, {\"o}ffentlichen Einrichtungen). Das RCER ist Ihr Partner beim Voranbringen von Kooperationen und Forschungsvorhaben durch Unterst{\"u}tzung in der Antragsphase, bei der Einwerbung von Projektmitteln und Projektbegleitung im Energiebereich. Das RCER steht f{\"u}r die Vermittlung von Know-how, Basiswissen, aktuellen Fragen und den Technologietransfer rund um das Thema Energie zwischen Wissenschaft, Wirtschaft, Gesellschaft und Politik. Vision Wir sind Ihr erster Ansprechpartner und Motor f{\"u}r innovative Energieforschung. Werte Verl{\"a}sslichkeit, Kompetenz, Verantwortungsbewusstsein.Regional verwurzelt und weltoffen}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Strom - W{\"a}rme - Verkehr - Industrie: das Zusammenspiel der Sektoren {\"u}ber Power-to-X}, series = {Deutscher Ingenieurtag 2021, D{\"u}sseldorf 20. Mai 2021}, journal = {Deutscher Ingenieurtag 2021, D{\"u}sseldorf 20. Mai 2021}, publisher = {VDI-Verlag}, language = {de} } @article{MikhaeilGadererDawoud, author = {Mikhaeil, Makram and Gaderer, Matthias and Dawoud, Belal}, title = {On the application of adsorber plate heat exchangers in thermally driven chillers}, series = {Applied Thermal Engineering}, volume = {220}, journal = {Applied Thermal Engineering}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2022.119713}, abstract = {The effect of both heat and mass transfer characteristic lengths (HTCL, MTCL) of two different adsorber plate heat exchangers (APHE), for application in an adsorption chiller, on the adsorption and desorption kinetics is investigated. Three representative test frames (TF1-TF3) are prepared to examine small-scale adsorbent samples of the microporous silica gel (Siogel of Oker-Chemie, Germany) applying the volumetric large-temperature-jump methodology at different operating conditions. Based on the obtained kinetic data, an analytical model has been developed to predict the specific cooling power (SCP) and the coefficient of performance (COP) of a single-bed adsorption chiller comprising the studied APHEs. It turned out that, within the tested range of HTCL and MTCL, it can be concluded that, the adsorption kinetics are mainly influenced by the MTCL, while the desorption kinetics are dominated by the HTCL of the adsorbent domain. Applying Siogel as loose pellets inside a newly introduced APHE results in of 423.3 and 182.7 W⋅kg-1, at the evaporator temperatures of 15 °C and 5 °C, respectively. Herein, the condenser and adsorber-end temperatures amount to 30 °C and the desorption-end temperature to 90 °C. The corresponding s amount to 0.50 and 0.40, respectively, which represent quite promising results for further design optimizations.}, 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} } @article{ThemaWeidlichKauletal., author = {Thema, Martin and Weidlich, Tobias and Kaul, Anja and B{\"o}llmann, Andrea and Huber, Harald and Bellack, Annett and Karl, J{\"u}rgen and Sterner, Michael}, title = {Optimized biological CO2-methanation with a pure culture of thermophilic methanogenic archaea in a trickle-bed reactor}, series = {Bioresource Technology}, journal = {Bioresource Technology}, number = {333}, publisher = {Elsevier}, doi = {10.1016/j.biortech.2021.125135}, abstract = {In this study, a fully automated process converting hydrogen and carbon dioxide to methane in a high temperature trickle-bed reactor was developed from lab scale to field test level. The reactor design and system performance was optimized to yield high methane content in the product gas for direct feed-in to the gas grid. The reaction was catalyzed by a pure culture of Methanothermobacter thermoautotrophicus IM5, which formed a biofilm on ceramic packing elements. During 600 h in continuous and semi-continuous operation in countercurrent flow, the 0.05 m3 reactor produced up to 95.3 \% of methane at a methane production rate of 0.35 mCH43mR-3h-1. Adding nitrogen as carrier gas during startup, foam control and dosing of ammonium and sodium sulfide as nitrogen and sulfur source were important factors for process automation.}, language = {en} } @article{GaertnerRankHeberletal., author = {G{\"a}rtner, Sebastian and Rank, Daniel and Heberl, Michael and Gaderer, Matthias and Dawoud, Belal and Haumer, Anton and Sterner, Michael}, title = {Simulation and Techno-Economic Analysis of a Power-to-Hydrogen Process for Oxyfuel Glass Melting}, series = {Energies}, volume = {14}, journal = {Energies}, number = {24}, publisher = {MDPI}, doi = {10.3390/en14248603}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-22713}, abstract = {As an energy-intensive industry sector, the glass industry is strongly affected by the increasingly stringent climate protection targets. As established combustion-based production systems ensure high process stability and glass quality, an immediate switch to low greenhouse gas emission processes is difficult. To approach these challenges, this work investigates a step-by-step integration of a Power-to-Hydrogen concept into established oxyfuel glass melting processes using a simulation approach. This is complemented by a case study for economic analysis on a selected German glass industry site by simulating the power production of a nearby renewable energy park and subsequent optimization of the power-to-hydrogen plant performance and capacities. The results of this study indicate, that the proposed system can reduce specific carbon dioxide emissions by up to 60\%, while increasing specific energy demand by a maximum of 25\%. Investigations of the impact of altered combustion and furnace properties like adiabatic flame temperature (+25 °C), temperature efficiency (∆ξ = -0.003) and heat capacity flow ratio (∆zHL = -0.009) indicate that pure hydrogen-oxygen combustion has less impact on melting properties than assumed so far. Within the case study, high CO2 abatement costs of 295 €/t CO2-eq. were determined. This is mainly due to the insufficient performance of renewable energy sources. The correlations between process scaling and economic parameters presented in this study show promising potential for further economic optimization of the proposed energy system in the future.}, 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{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} } @inproceedings{TremmelNaglerKutteretal., author = {Tremmel, Florian and Nagler, O. and Kutter, C. and Holmer, Rainer}, title = {Smart Cantilever Probe with Integrated Force and Acoustic Emission Sensor}, series = {2023 IEEE SENSORS, Vienna, Austria, 10/29/2023 - 11/1/2023}, booktitle = {2023 IEEE SENSORS, Vienna, Austria, 10/29/2023 - 11/1/2023}, publisher = {IEEE}, isbn = {979-8-3503-0387-2}, doi = {10.1109/SENSORS56945.2023.10325021}, pages = {1 -- 4}, abstract = {Acoustic emission (AE) testing recently found its application in the wafer testing sector of the semiconductor industry. To find out the mechanical robustness of semiconductor devices, contact pads on the chip surface are intentionally overstressed with an indenter tip and the appearing oxide cracks are detected with help of the generated AE signals. This is done in a customized test bench with a patented sensor-indenter system. This paper presents an improved version of the measurement setup that solves certain disadvantages of it and can be used in a standard wafer prober. The main components of the developed sensor system are a strain gauge for contact force measurement and a piezoelectric sensor element for AE signal detection. Both components are integrated on a cantilever beam which has an exchangeable indenter tip at its free end. The cantilever probe is electrically conductive to enable electrical tests via the indenter tip. This smart sensor-cantilever combination (SCC) can be mounted with several adapter components on a carrier plate to place it in a wafer prober. For both sensor elements amplifier circuits are developed to enhance their signal-to-noise ratios (SNRs). A prototype setup is shown together with simulated and experimental results to demonstrate its performance. The mechanical properties of the cantilever, as well as the force sensor and the AE crack signals, already fulfill the requirements for an implementation in a wafer prober. To further improve the sensor resolutions and detection limits, several optimizations regarding the design of the SCC are in progress.}, language = {en} } @article{ThemaBauerSterner, author = {Thema, Martin and Bauer, Franz and Sterner, Michael}, title = {Power-to-Gas: Electrolysis and methanation status review}, series = {Renewable and Sustainable Energy Reviews}, volume = {112}, journal = {Renewable and Sustainable Energy Reviews}, number = {7}, publisher = {Elsevier}, doi = {10.1016/j.rser.2019.06.030}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-26238}, pages = {775 -- 787}, abstract = {This review gives a worldwide overview on Power-to-Gas projects producing hydrogen or renewable substitute natural gas focusing projects in central Europe. It deepens and completes the content of previous reviews by including hitherto unreviewed projects and by combining project names with details such as plant location. It is based on data from 153 completed, recent and planned projects since 1988 which were evaluated with regards to plant allocation, installed power development, plant size, shares and amounts of hydrogen or substitute natural gas producing examinations and product utilization phases. Cost development for electrolysis and carbon dioxide methanation was analyzed and a projection until 2030 is given with an outlook to 2050. The results show substantial cost reductions for electrolysis as well as for methanation during the recent years and a further price decline to less than 500 euro per kilowatt electric power input for both technologies until 2050 is estimated if cost projection follows the current trend. Most of the projects examined are located in Germany, Denmark, the United States of America and Canada. Following an exponential global trend to increase installed power, today's Power-to-Gas applications are operated at about 39 megawatt. Hydrogen and substitute natural gas were investigated on equal terms concerning the number of projects.}, language = {en} } @article{MonkmanSindersbergerPrem, author = {Monkman, Gareth J. and Sindersberger, Dirk and Prem, Nina}, title = {Magnetically enhanced photoconductive high voltage control}, series = {ISSS Journal of Micro and Smart Systems}, volume = {11}, journal = {ISSS Journal of Micro and Smart Systems}, publisher = {Springer Nature}, doi = {10.1007/s41683-021-00088-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-30606}, pages = {317 -- 328}, abstract = {The recent surge of interest in electrostatic actuators, particularly for soft robotic applications, has placed increasing demands on high voltage control technology. In this respect, optoelectronic bidirectional switching and analogue regulation of high voltages is becoming increasingly important. One common problem is the leakage current due to dark resistance of the material or device used. Another is the physical size of such elements. However, their ability to provide galvanic separation makes them a very attractive alternative to conventional (wired) semiconductor elements. This paper gives an overview of available methods and devices before introducing a concept based on the combination of photoresistive and magnetoresistive effects in Gallium Arsenide that are potentially applicable to other semiconductor materials.}, language = {en} } @article{HaugVetter, author = {Haug, Sonja and Vetter, Miriam}, title = {Altersgerechtes Wohnen im Quartier}, series = {Standort - Zeitschrift f{\"u}r angewandte Geographie}, volume = {45}, journal = {Standort - Zeitschrift f{\"u}r angewandte Geographie}, publisher = {Springer Nature}, issn = {1432-220X}, doi = {10.1007/s00548-020-00678-3}, pages = {11 -- 17}, abstract = {Im Alter nimmt das Quartier aufgrund geringerer Aktionsradien an Bedeutung zu. Der Beitrag befasst sich mit der Frage, welche Besonderheiten sich bei Senioren-Haushalten im Hinblick auf Wohnen und soziale Teilhabe zeigen. Aus dem Projekt MAGGIE werden Ergebnisse einer schriftlichen Haushaltsbefragung (N=195) in der Wohngenossenschaft Margaretenau Regensburg dargestellt. Hierbei wird auf die aktuelle und zuk{\"u}nftige Wohnsituation, den Ver{\"a}nderungsbedarf, den Wunsch nach Gemeinschaftsangeboten und die soziale Einbettung eingegangen. Es zeigt sich eine geringe Ver{\"a}nderungsbereitschaft und ein {\"u}berdurchschnittlich hohes Maß an lokalem Sozialkapital. Am Ende werden Schlussfolgerungen f{\"u}r das Sanierungs- und Quartiersmanagement gezogen.}, subject = {Alter}, language = {de} } @article{HofrichterRankHeberletal., author = {Hofrichter, Andreas and Rank, Daniel and Heberl, Michael and Sterner, Michael}, title = {Determination of the optimal power ratio between electrolysis and renewable energy to investigate the effects on the hydrogen production costs}, series = {International Journal of Hydrogen Energy}, volume = {48}, journal = {International Journal of Hydrogen Energy}, number = {5}, publisher = {Elsevier}, issn = {0360-3199}, doi = {10.1016/j.ijhydene.2022.09.263}, pages = {1651 -- 1663}, abstract = {Green hydrogen via renewable powered electrolysis has a high relevance in decarbonization and supply security. Achieving economically competitive hydrogen production costs is a major challenge in times of an energy price crisis. Our objective is to show the economically optimal installed capacity of electrolysers in relation to wind and solar power so swift and credible statements can be made regarding the system design. The ratio between renewable generation and electrolysis power as well as scaling effects, operating behaviour and development of costs are considered. Hydrogen production costs are calculated for four exemplary real PV and wind sites and different ratios of electrolysis to renewable power for the year 2020. The ideal ratio for PV systems is between 14\% and 73\% and for wind between 3.3\% and 143\% for low and high full load hours. The lowest hydrogen production costs are identified at 2.53 €/kg for 50 MW wind power and 72 MW electrolysis power. The results provide plant constructors the possibility to create a cost-optimized design via an optimum ratio of electrolysis to renewable capacity. Therefore, the procedures for planning and dimensioning of selected systems can be drastically simplified.}, 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{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{SternerBauer, author = {Sterner, Michael and Bauer, Franz}, title = {Power-to-X im Kontext der Energiewende und des Klimaschutzes in Deutschland}, series = {Chemie-Ingenieur-Technik}, volume = {92}, journal = {Chemie-Ingenieur-Technik}, number = {1-2}, publisher = {Wiley}, issn = {0009-286X}, doi = {10.1002/cite.201900167}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-11669}, pages = {85 -- 90}, abstract = {Um den Einfluss verschiedener Power-to-X-Verfahren auf die Transformation des deutschen Energiesystems und das Erreichen der Klimaschutzziele zu {\"u}berpr{\"u}fen, wurde ein sektor{\"u}bergreifendes Energiesystemmodel entwickelt. Die daraus gewonnenen Ergebnisse zeigen: F{\"u}r eine erfolgreiche Energiewende ist der Einsatz von Power-to-X in Zukunft unverzichtbar. Vor allem in Bereichen und Sektoren, in denen hohe Energiedichten erforderlich und nur wenig andere Optionen zur Defossilisierung vorhanden sind, werden Power-to-X-Technologien zwingend notwendig.}, subject = {Power-to-Gas}, language = {de} } @article{SovacoolCabezaPiselloetal., author = {Sovacool, Benjamin K. and Cabeza, Luisa F. and Pisello, Anna Laura and Colladon, Andrea Fronzetti and Larijani, Hatef Madani and Dawoud, Belal and Martiskainen, Mari}, title = {Decarbonizing household heating: Reviewing demographics, geography and low-carbon practices and preferences in five European countries}, series = {Renewable \& Sustainable Energy Reviews}, journal = {Renewable \& Sustainable Energy Reviews}, number = {139}, publisher = {Elsevier}, doi = {10.1016/j.rser.2020.110703}, pages = {1 -- 28}, abstract = {What commonalities are there in sustainable or unsustainable heating practices in five high-income, high-emitting western European countries? What preferences do a nationally representative sample of the public in these countries hold towards low-carbon options? It is imperative that climate policy researchers and practitioners grapple with the difficulty of decarbonizing heat, which remains the largest single end-use service worldwide and which accounts about half of total final energy consumption. Based on a comparative assessment of five representative national surveys in Germany (N = 2009), Italy (N = 2039), Spain (N = 2038), Sweden (N = 2023), and the United Kingdom (N = 2000), this study explores the demographics and geography of household heat decarbonisation in Europe. By analyzing our country level data as well as our combined sample of 10,109 respondents, it investigates how people conceive of the purposes of low-carbon heat, their preferences for particular forms of heat supply, and their (at times odd) practices of heat consumption and temperature settings. Grounded in its original data, the study organizes its findings inductively across the five themes of literacy (heating knowledge, awareness and control), sustainability (heating practices, dynamics and conflicts), temperature (heating satisfaction and preferences), desirability of change (low-carbon heating priorities, business models and trust), and culture (country and national variation). The study also explores intersections between these dimensions, using multivariate analysis, as well as how preferences differ according to varying types of actors as well as geography and space.}, language = {en} } @article{MikhaeilNowakPalombaetal., author = {Mikhaeil, Makram and Nowak, Sebastian and Palomba, Valeria and Frazzica, Andrea and Gaderer, Matthias and Dawoud, Belal}, title = {Experimental and analytical investigation of applying an asymmetric plate heat exchanger as an evaporator in a thermally driven adsorption appliance}, series = {Applied Thermal Engineering}, journal = {Applied Thermal Engineering}, number = {228}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2023.120525}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-61115}, abstract = {This communication presents an experimental and analytical study on the evaporation mechanism in a closed-structured asymmetric plate heat exchanger (PHE) employed as a stagnant water evaporator for the application in an adsorption heat transformation appliance. To this aim, an experimental unit is constructed, which comprises two identical PHEs, one acting as an vaporator/condenser and the second, as an adsorber/desorber. Two endoscopes are mounted inside the investigated evaporator to visualize the evaporation mechanism when performing adsorption-evaporation processes under different boundary conditions. It turned out that the evaporation mechanism is a partially covered, thin film evaporation. A heat transfer analysis is performed to evaluate the heat transfer coefficient of the thin film evaporation () inside the investigated evaporator, resulting in -values between 1330 and 160 [W∙m-2∙K-1] over the investigated adsorption-evaporation time. Correlating the obtained () to the film thickness and the wetted area results in -values between 0.34 and 0.78 [mm] and wetted to total area ratios of 0.78 to 0.16. Besides, an analytical model has been developed and introduced to correlate the overall evaporator heat transfer coefficient with the adsorption potential and the time rate of change of the water uptake.}, language = {en} } @article{MonkmanSindersbergerPremetal., author = {Monkman, Gareth J. and Sindersberger, Dirk and Prem, Nina and Diermeier, Andreas and Szecsey, Tamara}, title = {Dielectric behaviour of magnetic hybrid materials}, series = {Physical Sciences Reviews}, volume = {7}, journal = {Physical Sciences Reviews}, number = {10}, publisher = {de Gruyter}, doi = {10.1515/psr-2019-0121}, pages = {1169 -- 1185}, abstract = {The objectives of this work include the analysis of electrical and magnetic properties of magneto-elastic hybrid materials with the intention of developing new techniques for sensor and actuator applications. This includes the investigation of dielectric properties at both low and high frequencies. The behaviour of capacitors whose dielectrics comprise magnetic hybrid materials is well known. Such interfacial magnetocapacitance can be varied according to magnetic content, magnetic flux density and the relative permittivity of the polymer matrix together with other dielectric content. The basic function of trapping electrical charges in polymers (electrets) is also established technology. However, the combination of magnetoactive polymers and electrets has led to the first electromagnetic device capable of adhering to almost any material, whether magnetically susceptible or not. During the course of this research, in addition to dielectrics, electrically conductive polymers based on (PDMS) matrices were developed in order to vary the electrical properties of the material in a targeted manner. In order to ensure repeatable results, this demanded new fabrication techniques hitherto unavailable. The 3D printing of silicones is far from being a mature technology and much pioneering work was necessary before extending the usual 3 d.o.f. to include orientation about and diffusion of particles in these three axes, thus leading to the concept of 6D printing. In 6D printing, the application of a magnetic field can be used during the curing process to control the particulate distribution and thus the spatial filler particle density as desired. Most of the devices (sensors and actuators) produced by such methods contain levels of carbonyl iron powder (CIP) embedded magnetic filler of up to 70 wt\%. Contrary to this, a hitherto neglected research area, namely magnetoactive polymers (MAPs) having significantly lower magnetic particle concentrations (1 to 3 wt\% CIP) were also investigated. With filler concentrations lower than 3 wt\%, structures are formed which are completely absent at higher filler levels. CIP concentrations in the range of 1wt\% demonstrate the formation of toroidal structures. Further development of coherent rings with a compact order results as filler concentrations increase towards 2 wt\%. Above 3 wt\% the structure eventually disintegrates to the usual random order found in traditional MAP with higher CIP content. Structured samples containing 1\%-3 wt\% CIP were investigated with the aid of X-ray tomography where solitary ring structures can be observed and eventually the formation of capillary doubles. Over wavelengths ranging from 1 to 25 µm, spectroscopic analysis of thin film MAP samples containing 2 wt\% CIP revealed measurable magnetic-field-dependent changes in IR absorption at a wavenumber 2350 (λ = 4.255 µm). This was found to be due to the diamagnetic susceptibility of atmospheric carbon dioxide (CO2). Consequently, the first potential application for sparse matrix MAPs was found.}, language = {en} } @article{MikhaeilGadererDawoud, author = {Mikhaeil, Makram and Gaderer, Matthias and Dawoud, Belal}, title = {On the development of an innovative adsorber plate heat exchanger for adsorption heat transformation processes; an experimental and numerical study}, series = {Energy}, volume = {207}, journal = {Energy}, number = {September}, publisher = {Elsevier}, doi = {10.1016/j.energy.2020.118272}, pages = {1 -- 13}, abstract = {An innovative adsorber plate heat exchanger (APHE), which is developed for application in adsorption heat pumps, chillers and thermal energy storage systems, is introduced. A test frame has been constructed as a representative segment of the introduced APHE for applying loose grains of AQSOA-Z02. Adsorption kinetic measurements have been carried out in a volumetric large-temperature-jump setup under typical operating conditions of adsorption processes. A transient 2-D model is developed for the tested sample inside the setup. The measured temporal uptake variations with time have been fed to the model, through which a micro-pore diffusion coefficient at infinite temperature of 2 E-4 [m2s-1] and an activation energy of 42.1 [kJ mol-1] have been estimated. A 3-D model is developed to simulate the combined heat and mass transfer inside the APHE and implemented in a commercial software. Comparing the obtained results with the literature values for an extruded aluminium adsorber heat exchanger coated with a 500 μm layer of the same adsorbent, the differential water uptake obtained after 300 s of adsorption (8.2 g/100 g) implies a sound enhancement of 310\%. This result proves the great potential of the introduced APHE to remarkably enhance the performance of adsorption heat transformation appliances.}, language = {en} } @article{MonkmanStrieglPremetal., author = {Monkman, Gareth J. and Striegl, Birgit and Prem, Nina and Sindersberger, Dirk}, title = {Electrical Properties of Magnetoactive Boron-Organo-Silicon Oxide Polymers}, series = {Macromolecular Chemistry and Physics}, volume = {221}, journal = {Macromolecular Chemistry and Physics}, number = {4}, publisher = {Wiley}, doi = {10.1002/macp.201900342}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-26488}, pages = {1 -- 8}, abstract = {The electrical properties of rheopectic magnetoactive composites comprising boron-organo-silicon oxide dielectric matrices containing carbonyl iron microparticles are presented for the first time. The increase in interfacial magnetocapacitance is seen to greatly exceed that experienced when using conventional elastomeric matrices such as polydimethylsiloxane. In addition to the increase in capacitance, a simultaneous and sharp decrease in the parallel electrical resistance over several orders of magnitude is also observed. The effects are time dependent but repeatable. Potential applications include magnetically controlled frequency dependent devices, magnetic sensor systems, weighting elements for neural networks, etc.}, language = {en} } @article{PremSindersbergerMonkman, author = {Prem, Nina and Sindersberger, Dirk and Monkman, Gareth J.}, title = {Infrared spectral analysis of low concentration magnetoactive polymers}, series = {Journal of Applied Polymer Science}, volume = {137}, journal = {Journal of Applied Polymer Science}, number = {7}, publisher = {Wiley}, organization = {WILEY}, issn = {1097-4628}, doi = {10.1002/app.48366}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-25913}, pages = {1 -- 7}, abstract = {This work concerns an area of magnetoactive polymer (MAP) research seldom considered. Traditionally only MAP with high concentrations of magnetic filler (typically between 10 and 90 wt\%) have been investigated. This article deals with a hitherto neglected aspect of research, namely MAP containing lower magnetic filler concentrations (1 to 3 wt\%). This article utilizes a range of spectroscopic analysis methods (Raman and FTIR) and their applicability to MAP characterization at wavelengths ranging from 2.5 to 25 mu m. Particular attention is paid to low carbonyl iron particle (CIP) concentrations in MAP for which the emergence of capillary doublets at a critical 2 wt\% concentration is revealed. This results in measurable magnetic field-dependent changes in IR absorption at a wavelength of 4.255 mu m together with a detectable CO2 susceptibility. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48366.}, language = {en} } @article{MetschSchmidtSindersbergeretal., author = {Metsch, P. and Schmidt, H. and Sindersberger, Dirk and Kalina, K. A. and Brummund, J. and Auernhammer, G{\"u}nter and Monkman, Gareth J. and K{\"a}stner, Markus}, title = {Field-Induced Interactions in Magneto-Active Elastomers}, series = {Smart Materials and Structures}, volume = {29}, journal = {Smart Materials and Structures}, number = {8}, publisher = {IOPscience}, doi = {10.1088/1361-665X/ab92dc}, pages = {1 -- 10}, abstract = {In this contribution, field-induced interactions of magnetizable particles embedded into a soft elastomer matrix are analyzed with regard to the resulting mechanical deformations. By comparing experiments for two-, three- and four-particle systems with the results of finite element simulations, a fully coupled continuum model for magneto-active elastomers is validated with the help of real data for the first time. The model under consideration permits the investigation of magneto-active elastomers with arbitrary particle distances, shapes and volume fractions as well as magnetic and mechanical properties of the individual constituents. It thus represents a basis for future studies on more complex, realistic systems. Our results show a very good agreement between experiments and numerical simulations—the deformation behavior of all systems is captured by the model qualitatively as well as quantitatively. Within a sensitivity analysis, the influence of the initial particle positions on the systems' response is examined. Furthermore, a comparison of the full three-dimensional model with the often used, simplified two-dimensional approach shows the typical overestimation of resulting interactions in magneto-active elastomers.}, 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{SchmidtStraubSindersbergeretal., author = {Schmidt, Henrik and Straub, Benedikt B. and Sindersberger, Dirk and Br{\"o}ckel, Ulrich and Monkman, Gareth J. and Auernhammer, G{\"u}nter}, title = {Collision and separation of nickel particles embedded in a Poly dimethylsiloxan matrix under a rotating magnetic field: A strong magneto active function}, series = {Colloid and Polymer Science}, volume = {299}, journal = {Colloid and Polymer Science}, publisher = {Springer}, doi = {10.1007/s00396-020-04784-4}, pages = {955 -- 967}, abstract = {In order to function as soft actuators, depending on their field of use, magnetorheological elastomers (MREs) must fulfill certain criteria. To name just a few, these can include rapid response to external magnetic fields, mechanical durability, mechanical strength, and/or large deformation. Of particular interest are MREs which produce macroscopic deformation for small external magnetic field variations. This work demonstrates how this can be achieved by just a small change in magnetic field orientation. To achieve this, (super)paramagnetic nickel particles of size ≈ 160 μm were embedded in a non-magnetic polydimethylsiloxan (PDMS) (661-1301 Pa) and their displacement in a stepwise rotated magnetic field (170 mT) recorded using a video microscope. Changes in particle aggregation resulting from very small variations in magnetic field orientation led to the observation of a new strongly magneto-active effect. This configuration is characterized by an interparticle distance in relation to the angle difference between magnetic field and particle axis. This causes a strong matrix deformation which in turn demonstrates hysteresis on relaxation. It is shown that the occurrence strongly depends on the particle size, particle distance, and stiffness of the matrix. Choosing the correct parameter combination, the state can be suppressed and the particle-matrix system demonstrates no displacement or hysteresis. In addition, evidences of non-negligible higher order magnetization effects are experimentally ascertained which is qualitatively in agreement with similar, already theoretically described, particle systems. Even at larger particle geometries, the new strongly magneto-active configuration is preserved and could create macroscopic deformation changes.}, language = {en} } @article{KeinerThomaBogdanovetal., author = {Keiner, Dominik and Thoma, Christian and Bogdanov, Dmitrii and Breyer, Christian}, title = {Seasonal hydrogen storage for residential on- and off-grid solar photovoltaics prosumer applications: Revolutionary solution or niche market for the energy transition until 2050?}, series = {Applied Energy}, volume = {340}, journal = {Applied Energy}, publisher = {Elsevier}, doi = {10.1016/j.apenergy.2023.121009}, pages = {17}, abstract = {Appropriate climate change mitigation requires solutions for all actors of the energy system. The residential sector is a major part of the energy system and solutions for the implementation of a seasonal hydrogen storage system in residential houses has been increasingly discussed. A global analysis of prosumer systems including seasonal hydrogen storage with water electrolyser, hydrogen compressor, storage tank, and a fuel cell studying the role of such a seasonal household storage in the upcoming decades is not available. This study aims to close this research gap via the improved LUT-PROSUME model, which models a fully micro sector coupled residential photovoltaic prosumer system with linear optimisation for 145 regions globally. The modelling of the cost development of hydrogen storage components allows for the simulation of a residential system from 2020 until 2050 in 5-year steps in hourly resolution. The systems are cost-optimised for either on- or off-grid operation in eight scenarios including battery electric vehicles, which can act as an additional vehicle-to-home electricity storage for the system. Results show that implementation of seasonal hydrogen systems only occurs in least cost solutions in high latitude countries when the system is forced to run in off-grid mode. In general, a solar photovoltaic plus battery system including technologies that can cover the heat demand is the most economic choice and can even achieve lower cost than a full grid supply in off-grid operation for most regions until 2050. Additional parameters including the self-consumption ratio, the demand cover ratio, and the heat cover ratio can therefore not be improved by seasonal storage systems if economics is the main deciding factor for a respective system. Further research opportunities and possible limitations of the system are then identified.}, language = {en} } @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} } @inproceedings{FrauenschlaegerDentgenMottok, author = {Frauenschl{\"a}ger, Tobias and Dentgen, Manuel and Mottok, J{\"u}rgen}, title = {Systemarchitektur eines Sicherheitsmoduls im Energiesektor}, series = {Tagungsband 2. Symposium Elektronik und Systemintegration ESI 2020: "Intelligente Systeme und ihre Komponenten: Forschung und industrielle Anwendung"}, booktitle = {Tagungsband 2. Symposium Elektronik und Systemintegration ESI 2020: "Intelligente Systeme und ihre Komponenten: Forschung und industrielle Anwendung"}, address = {Landshut}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:860-opus4-2092}, pages = {29 -- 38}, abstract = {Aufgrund der immer weiter anwachsenden Vernetzung der Stromnetze wird die Kommunikation zwischen der Leitstelle des Energieversorgers und den Infrastrukturkomponenten innerhalb eines Umspannwerks immer bedeutsamer. Dabei werden sowohl Steuerbefehle als auch Daten f{\"u}r {\"U}berwachungsfunktionen {\"u}bertragen. In den aktuellen Netzwerkarchitekturen findet diese Kommunikation ohne eine kryptografische Absicherung statt, was einen Angriffspunkt f{\"u}r gezielte Attacken und damit eine potenzielle Gef{\"a}hrdung der Energieversorgung darstellt. Um solchen Angriffen in Zukunft entgegenzuwirken, wird das ES³M-Sicherheitsmodul entwickelt. Dieses soll in das Netzwerk zwischen den beiden Kommunikationspartnern eingesetzt werden und so den Datenverkehr absichern. Mithilfe einer Bedrohungsanalyse wurden Anforderungen abgeleitet, die neben kryptografischen Maßnahmen auch Themen wie funktionale Sicherheit und Langlebigkeit umfassen. Um diese zu erf{\"u}llen, wurde eine spezielle Systemarchitektur auf Basis einer Aufgabenteilung entworfen. Diese Architektur und korrespondierende Designentscheidungen werden pr{\"a}sentiert.}, language = {de} } @inproceedings{LaloSailerMottoketal., author = {Lalo, Erjola and Sailer, Andreas and Mottok, J{\"u}rgen and Siemers, Christian}, title = {Overhead-Aware Schedule Synthesis for Logical Execution Time (LET) in Automotive Systems}, series = {2022 IEEE 35th International System-on-Chip Conference (SOCC): 05-08 September 2022, Belfast, United Kingdom}, booktitle = {2022 IEEE 35th International System-on-Chip Conference (SOCC): 05-08 September 2022, Belfast, United Kingdom}, publisher = {IEEE}, isbn = {978-1-6654-5985-3}, doi = {10.1109/SOCC56010.2022.9908103}, pages = {1 -- 6}, abstract = {The Logical Execution Time (LET) has recently been integrated in multi-core automotive systems to ensure timing and dataflow determinism. Although buffering mechanisms are introduced to incorporate LET semantics, they do not guarantee that tasks are executed within their LET frames. In fact, LET and buffering semantics are violated if scheduling is not designed to execute all tasks within their LET frames and in a specific order. In this paper, we describe a scheduling synthesis technique for Fixed-Priority Scheduling (FPS) to achieve resource-efficient execution of LET systems. The proposed approach considers LET semantics, scheduling overheads, and delays caused by operating system operations and provides the possibility to optimize the schedule with respect to aspects like scheduling overheads. Our performance and feasibility evaluation shows that the proposed algorithm provides results in a reasonable amount of time for models of complex industrial applications. Thus, the integration of the proposed algorithm into an automated process is of high benefit to accelerate the development of vehicle applications.}, language = {en} } @inproceedings{MuchaMottokKraemer, author = {Mucha, Matthias and Mottok, J{\"u}rgen and Kr{\"a}mer, Stefan}, title = {Estimation of Worst Case Response Time Boundaries in Multi-Core Real-Time Systems}, series = {2017 International Conference on Applied Electronics (AE), 5-6 Sept. 2017, Pilsen}, booktitle = {2017 International Conference on Applied Electronics (AE), 5-6 Sept. 2017, Pilsen}, publisher = {IEEE}, isbn = {978-80-261-0641-8}, issn = {1803-7232}, doi = {10.23919/ae.2017.8053598}, pages = {1 -- 6}, abstract = {We address a novel probabilistic approach to estimate the Worst Case Response Time boundaries of tasks. Multi-core real-time systems process tasks in parallel on two or more cores. Tasks in our contribution may preempt other tasks, block tasks with semaphores to access global shared resources, or migrate to another core. The depicted task behavior is random. The shape of collected response times of a task within a processing time is multimodal. Extreme Value approaches need unimodal response time distributions to estimate the Worst Case Response Time of tasks. The new proposed method derives a set of three task set shapes from the source task set. It is used to minimize the uncertainty of random task behavior by maximizing the coverage of possible Worst Case Response Times. The case study evaluates the new proposed estimation method by the use of dynamically generated random tasks with varying task properties.}, language = {en} } @article{FederrathMottokPloessletal., author = {Federrath, H. and Mottok, J{\"u}rgen and Pl{\"o}ßl, K. and V{\"o}lkl, Thomas}, title = {Automotive safety and security}, series = {Jahresr{\"u}ckblick 2007 des Bayerischen IT-Sicherheitsclusters}, journal = {Jahresr{\"u}ckblick 2007 des Bayerischen IT-Sicherheitsclusters}, pages = {25}, language = {de} } @inproceedings{DeNiklasRooneyetal., author = {De, Sangita and Niklas, Michael and Rooney, Brian and Mottok, J{\"u}rgen and Brada, Premek}, title = {Towards Translation of Semantics of Automotive Interface Description Models from Franca to AUTOSAR Frameworks}, 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}, publisher = {University of West Bohemia}, doi = {10.23919/AE.2019.8867018}, pages = {1 -- 6}, abstract = {The automotive industry is eventually evolving into a complex network of services. The heterogeneous and distributed nature of automotive software systems demands flexible software components which can operate in different environments. Because of heterogeneous automotive development environments, the domain experts, must cope with too many diversities, adaption layers, and incompatibilities to design applications for the current generation of autonomous driving vehicles. In this context, interface adaptation is a promising approach to achieve flexibility without directly changing the respective components. AUTOSAR, which is the de-facto standard for describing automotive system architecture and is a hugely comprehensive standard allowing designers full control from abstract system description to bare metal level deployment. However, the vehicle subsystems have still evolved to include multifarious high-level domains not covered by AUTOSAR e.g. Infotainment, Telematics etc. Therefore, it seems beneficial to bridge the semantic gaps between AUTOSAR applications and other standards of automotive application domains. The goal of this paper is to investigate interface semantic mapping and achieve transparent integration of domain-specific applications using the translation of semantics among the AUTOSAR platform software component models and other software components models of open source development platforms e.g. GENIVI. A key goal of such a modelling approach is the reuse of existing interface description languages and respective code generators. This will enhance future interoperability and decrease in incompatibility among these platforms.}, 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} } @article{DiermeierSindersbergerKrenkeletal., author = {Diermeier, Andreas and Sindersberger, Dirk and Krenkel, Lars and Rosell, X. C. and Monkman, Gareth J.}, title = {Controllable Magnetoactive Polymer Conduit}, series = {The Open Mechanical Engineering Journal}, volume = {12}, journal = {The Open Mechanical Engineering Journal}, number = {1}, publisher = {Bentham}, pages = {192 -- 200}, abstract = {Objective: Magneto-active Polymers (MAP) are smart materials whose mechanical characteristics, such as elastic and shear moduli, may be controllable by means of an externally applied magnetic field. Methods: Various additives may be used to influence the characteristics of the polymer matrix whilst a suspension of soft and/or hard magnetic particles determine the magnetic properties of the composite. Both pre-cure and post-cure magnetization is possible. Results: A range of control strategies have been investigated for evaluation of the system using fluids of differing kinematic viscosity. Conclusion: Depending on the degree of magnetic field homogeneity, magneto-deformation and magnetostriction contribute to MAP actuation. This paper presents a novel application in the form of a peristaltic MAP tube system, applicable to flow control and pumping of hemorheological fluids in blood circulatory systems for biomedical research purposes.}, 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{DePremekMottok, author = {De, Sangita and Premek, Brada and Mottok, J{\"u}rgen}, title = {Derivation of Optimized Threshold of Semantic Alignment Metrics for Intepretation of Interoperability and Reusability of Cross-enterprise Vehicle Service Interface Models}, series = {Informatica}, volume = {47}, journal = {Informatica}, number = {7}, publisher = {Slovenian Society Informatika}, issn = {0350-5596}, doi = {10.31449/inf.v47i7.4739}, abstract = {Over the past decade, cars have turned gradually into real cyber physical systems. The collaboration of services between the service-oriented, cross-enterprise vehicle application frameworks has increased to generate novel, smart and complicated vehicle services. Consequently, from an interoperability perspective, semantically mapping of vehicle service component's interface ontological models emerged as a big research interest in automotive application domain that manipulates several cross-enterprise synergy knowledge applications frameworks. The ontological metamodeling lays the foundation for building semantic bridge and exploring semantic associations between service components' interface models based on the domain knowledge for semantic interoperability. Also, several semantic quality metrics has been defined over time for the vehicle service interface ontological metamodels. The empirically evaluated values of these metrics can be used to assess progress in cross-enterprise interoperability between the service and the clients' APIs ontological models in vehicle domain. Despite potential benefits of semantic alignment quality metrics, the effective use of these metrics for vehicle service interface ontologies have proven elusive. Yes, such metrics can be used successfully for quantification, but then they mostly fail to provide adequate annotations in subsequent decision-making in the direction of semantic interoperability and reusability. The effective use of ontology semantic alignment quality metrics is basically hindered in the absence of the meaningful thresholds. In fact, the absence of an effective and meaningful threshold for the semantic similarity measure between various vehicle service interface ontological metamodels, motivates this research work which not only proposes a design approach to an optimized threshold for the semantic similarity metrics but also applies this threshold on few defined semantic alignment quality metrics. This paper also uses a real-world vehicle domain industrial case study to illustrate the design approach.}, language = {en} } @inproceedings{Franke, author = {Franke, Ariane}, title = {Electricity load forecasting for industrial microgrid and load management}, series = {Applied Research Conference 2022 Conference Proceedings: 4th July 2022, University of Applied Sciences Ansbach (Onsite Conference)}, booktitle = {Applied Research Conference 2022 Conference Proceedings: 4th July 2022, University of Applied Sciences Ansbach (Onsite Conference)}, editor = {Uhl, Christian and Walter, Michael and Stiehl, Annika}, publisher = {Hochschule Ansbach}, address = {Ansbach}, doi = {10.25929/qbwt-zf40}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-68231}, pages = {405 -- 409}, abstract = {As more energy systems from renewable sources and the electricity market becomes more volatile, new solutions to ensure the security of supply are tested. Microgrids offer a possibility to prevent construction downtime. In order to use the energy sources and storage facilities of the microgrid effectively, load forecasting algorithms are essential. Thus, in this study a short term load forecasting model for a construction company is designed, that will be used for managing a microgrid as well as the general load consumption. This paper proposes the use of the XGBoost algorithm for the 36-hour forecast including predictors based on past measurements as well as information extracted from the timestamp. Moreover, it is shown that including load profiles attained by conventional methods has the potential to improve the accuracy of the model.}, language = {en} } @article{HuberHeindlSchlosseretal., author = {Huber, Lea and Heindl, Melanie and Schlosser, Marc and Pfitzner, Arno and Dawoud, Belal}, title = {On the Cycle Stability and Macroscopic Structure of Iron Oxide Pellets for Thermochemical Hydrogen Storage: Influence of Water Content during the Pelletizing Process}, series = {Applied Sciences}, volume = {13}, journal = {Applied Sciences}, number = {11}, publisher = {MDPI}, address = {16}, doi = {10.3390/app13116408}, abstract = {Hydrogen storage based on the repeated reduction and oxidation (redox) reactions of iron oxide/iron composites represents a promising technology. This work is dedicated to studying the influence of the amount of water added during the pelletizing process on the cycle stability and structure of iron oxide pellets. The storage composites were prepared from iron oxide (Fe2O3) and 10 wt.-\% support material (cement) with different amounts of water (18 and 33 wt.-\%) in a laboratory-scale pelletizing disk. To evaluate the cycle stability of the composites, the kinetics of the redox reactions were experimentally measured at 800 ∘ C in an atmosphere of 50\% N2 and 50\% H2 (reduction) or 50\% steam (oxidation), respectively. Moreover, the structure of the pellets was analyzed by micro-computed tomography scans. It turned out that pellets with higher water contents attained faster kinetics and a higher cycle stability. The sample with the least water content (18 wt.-\%) needed about 26 min and 19 min to reach a conversion rate of 80\% during the reduction and oxidation reactions of the sixth redox cycle, respectively. In contrast, the sample with the highest water content (33 wt.-\%) could achieve the same conversion rate after 18 min (reduction) and 13 min (oxidation) during the ninth redox cycle.}, language = {en} } @article{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Rabl, Hans-Peter and Dietrich, Markus and Moos, Ralf}, title = {Combined Ash and Soot Monitoring for Gasoline Particulate Filters Using a Radio-Frequency-Based Sensor}, series = {Emission Control Science and Technology}, journal = {Emission Control Science and Technology}, publisher = {Springer}, doi = {10.1007/s40825-023-00235-y}, pages = {9}, abstract = {Increasingly stringent emission limits have made particulate filters necessary for gasoline engines. Similar to diesel applications, gasoline particulate filters (GPFs) can be monitored by differential pressure measurement or by the radio-frequency-based filter diagnosis (RF sensor). In addition to measuring the soot loading, ash detection is critical for monitoring the GPF over the entire vehicle lifetime. Because the RF sensor detects the filter loading through a change in the dielectric properties of the GPF, it can detect not only soot but also ash. In diesel applications, the RF sensor has already demonstrated its potential for ash detection. To verify the feasibility of simultaneous ash and soot monitoring for GPFs, filters were loaded with ash on an engine test bench and measured on a lab test bench under defined synthetic exhaust gas conditions. By evaluating resonant modes, soot and ash could be clearly distinguished, as ash mainly affects the resonant frequency, while soot also changes the quality factor due to its high dielectric losses. However, higher soot loadings could not be detected by the resonant parameters, but instead by a frequency-averaged transmission signal. While the presence of ash caused an offset in this signal, its sensitivity to soot was not affected. Thus, the influence of ash can be corrected if the signal in the soot-free filter state is known, e.g., from the behavior of the resonant parameters. Therefore, even with a continuously increasing ash loading over the lifetime of a vehicle, an accurate soot detection is possible with the RF sensor.}, language = {en} } @incollection{BauerGawlikSterneretal., author = {Bauer, Franz and Gawlik, Julia and Sterner, Michael and Hamacher, Thomas}, title = {{\"U}bergreifende Energiesystemmodellierung}, series = {Optionen f{\"u}r ein nachhaltiges Energiesystem mit Power-to-X-Technologien: Transformation - Anwendungen - Potentiale. 4. Roadmap des Kopernikus-Projektes P2X, Phase II}, booktitle = {Optionen f{\"u}r ein nachhaltiges Energiesystem mit Power-to-X-Technologien: Transformation - Anwendungen - Potentiale. 4. Roadmap des Kopernikus-Projektes P2X, Phase II}, editor = {Ausfelder, Florian and Du Tran, Dinh}, publisher = {DECHEMA Gesellschaft f{\"u}r Chemische Technik und Biotechnologie e.V.}, address = {Frankfurt a.M.}, isbn = {978-3-89746-238-0}, pages = {17 -- 35}, language = {de} } @incollection{BauerGawlikSterneretal., author = {Bauer, Franz and Gawlik, Julia and Sterner, Michael and Hamacher, Thomas}, title = {{\"U}bergreifende Energiesystemmodellierung}, series = {Optionen f{\"u}r ein nachhaltiges Energiesystem mit Power-to-X-Technologien: Transformation - Anwendungen - Potentiale. 3. Roadmap des Kopernikus-Projektes P2X, Phase II}, booktitle = {Optionen f{\"u}r ein nachhaltiges Energiesystem mit Power-to-X-Technologien: Transformation - Anwendungen - Potentiale. 3. Roadmap des Kopernikus-Projektes P2X, Phase II}, editor = {Ausfelder, Florian and Dura, Hanna}, publisher = {DECHEMA Gesellschaft f{\"u}r Chemische Technik und Biotechnologie e.V.}, address = {Frankfurt a.M.}, isbn = {978-3-89746-236-6}, pages = {19 -- 33}, language = {de} } @misc{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Rabl, Hans-Peter and Dietrich, Markus and Moos, Ralf}, title = {Combined Ash and Soot Monitoring in Gasoline Particulate Filters with a Radio-Frequency-Based Sensor}, series = {SAE World Congress Experience, April 5-7, 2022, Detroit, Michigan, USA}, journal = {SAE World Congress Experience, April 5-7, 2022, Detroit, Michigan, USA}, abstract = {In recent years, it turned out that primarily the number of ultrafine particles and not their mass is relevant in terms of harmful health effects. Therefore, exhaust emission standards are constantly being tightened with regard to the particulate number. To meet the emission limits, particulate filters have become necessary for gasoline engines. Similar to diesel applications, gasoline particulate filters (GPFs) can be monitored via differential pressure measurement or via a radio-frequency approach (RF-sensor). The latter is based on the influence of the soot conductivity on the electromagnetic field. To control the GPF, ash detection is of crucial importance besides the soot load monitoring. With the differential pressure system, this is only possible with high uncertainties due to the low pressure increase caused by ash. The RF-sensor, however, has already demonstrated its potential for ash detection in diesel applications. In order to verify the applicability of the system for GPFs, filters were loaded via a method for fast ash loading. Thereby, it was shown that by evaluating resonant modes - especially the resonant frequency - the ash loading can easily be measured as long as the filter is soot-unloaded. In contrast, soot loading can be determined independently from this by considering a frequency-averaged transmission signal between the antennas of the RF-sensor. Using a setup for radio-frequency material characterization, the dielectric parameters of the generated ash were also measured. In comparison with the properties of the synthetic soot PrintexU, ash showed significantly lower dielectric losses. Thus, the evaluation of the loss-dependent quality factor, which is only possible at low soot loadings, allows a precise conclusion whether the filter is completely soot-free. Furthermore, using synthetic soot loading, it could be shown that soot detection via the averaged transmission signal is not affected by ash. In summary, it could be shown that with the RF-sensor, ash and soot can be simultaneously detected.}, language = {en} }