TY - JOUR A1 - Kurzweil, Peter A1 - Scheuerpflug, Wolfgang T1 - State-of-charge monitoring and battery diagnosis of different lithium ion chemistries using impedance spectroscopy JF - Batteries N2 - For lithium iron phosphate batteries (LFP) in aerospace applications, impedance spectroscopy is applicable in the flat region of the voltage-charge curve. The frequency-dependent pseudocapacitance at 0.15 Hz is presented as useful state-of-charge (SOC) and state-of-health (SOH) indicator. For the same battery type, the prediction error of pseudocapacitance is better than 1% for a quadratic calibration curve, and less than 36% for a linear model. An approximately linear correlation between pseudocapacitance and Ah battery capacity is observed as long as overcharge and deep discharge are avoided. We verify the impedance method in comparison to the classical constant-current discharge measurements. In the case of five examined lithium-ion chemistries, the linear trend of impedance and SOC is lost if the slope of the discharge voltage curve versus SOC changes. With nickel manganese cobalt (NMC), high impedance modulus correlates with high SOC above 70%. KW - battery life testing KW - capacitance KW - lithium-ion battery KW - state-of-charge determination KW - state-of-health KW - pseudocharge KW - impedance spectroscopy KW - aging Y1 - 2021 U6 - https://doi.org/10.3390/batteries7010017 VL - 7 IS - 1 ER - TY - JOUR A1 - Schmidt, Henrik A1 - Straub, Benedikt B. A1 - Sindersberger, Dirk A1 - Bröckel, Ulrich A1 - Monkman, Gareth J. A1 - Auernhammer, Günter T1 - Collision and separation of nickel particles embedded in a Poly dimethylsiloxan matrix under a rotating magnetic field: A strong magneto active function JF - Colloid and Polymer Science N2 - 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. Y1 - 2021 U6 - https://doi.org/10.1007/s00396-020-04784-4 VL - 299 SP - 955 EP - 967 PB - Springer ER - TY - JOUR A1 - Schroll-Decker, Irmgard T1 - Rezension zu: Ethik des Wissens. Freiheit und Verantwortung der Wissenschaft in Zeiten des Klimawandels. oekom Verlag (München) 2019. ISBN 978-3-96238-163-9 JF - socialnet Rezensionen Y1 - 2020 UR - https://www.socialnet.de/rezensionen/26341.php SN - 2190-9245 ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Yuskevich, Pavel T1 - Effective medium theory for the elastic properties of composite materials with various percolation thresholds JF - Materials N2 - It is discussed that the classical effective medium theory for the elastic properties of random heterogeneous materials is not congruous with the effective medium theory for the electrical conductivity. In particular, when describing the elastic and electro-conductive properties of a strongly inhomogeneous two-phase composite material, the steep rise of effective parameters occurs at different concentrations. To achieve the logical concordance between the cross-property relations, a modification of the effective medium theory of the elastic properties is introduced. It is shown that the qualitative conclusions of the theory do not change, while a possibility of describing a broader class of composite materials with various percolation thresholds arises. It is determined under what conditions there is an elasticity theory analogue of the Dykhne formula for the effective conductivity. The theoretical results are supported by known experiments and show improvement over the existing approach. The introduction of the theory with the variable percolation threshold paves the way for describing the magnetorheological properties of magnetoactive elastomers. A similar approach has been recently used for the description of magneto-dielectric and magnetic properties. KW - elastic properties KW - effective medium approximation KW - self-consistent KW - random heterogeneous medium KW - two-phase composite material KW - percolation threshold Y1 - 2020 U6 - https://doi.org/10.3390/ma13051243 VL - 13 IS - 5 SP - 1 EP - 19 PB - MPDI CY - Basel ER - TY - CHAP A1 - Bünte, Tilman A1 - Rill, Georg A1 - Ruggaber, Julian A1 - Tobolář, Jakub ED - Orlova, Anna ED - Cole, David T1 - Modelling and Validation of the TMeasy Tyre Model for Extreme Parking Manoeuvres T2 - Advances in Dynamics of Vehicles on Roads and Tracks II, Proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia N2 - The TMeasy is a tyre model suitable for vehicle handling analyses and enables easy parametrisation. Recently, a convenient interface to Modelica was implemented by DLR to support the TMeasy also for vehicle modelling in multi-physical domains. This paper focuses especially on the particular problem of reliable reproduction of the tyre’s bore torque which occurs during parking manoeuvres. It outlines the theory behind it, discusses the Modelica interface implementation, and presents the results of parameter identification which were achieved based on real experiments with DLR’s research platform ROboMObil. Y1 - 2022 SN - 978-3-031-07305-2 SN - 978-3-031-07304-5 U6 - https://doi.org/10.1007/978-3-031-07305-2_94 SP - 1015 EP - 1025 PB - Springer CY - Cham ER - TY - JOUR A1 - Rill, Georg A1 - Bauer, Florian A1 - Topcagic, Edin T1 - Performance of leaf spring suspended axles in model approaches of different complexities JF - Vehicle System Dynamics N2 - Axles with leaf spring suspension systems are still a popular choice in many commercial vehicles. However, leaf springs are not in perfect conformity to standard multibody vehicle models because they combine guidance and suspension in one single element. Combining standard multibody vehicle models with sophisticated finite element leaf spring models results in rather complex and computing time-consuming solutions. Purely kinematic models, defined by lookup tables or the design kinematics approach, cover only some but not all features of the leaf spring suspension. As shown here, the five-link model, which incorporates a quasi-static solution of the leaf spring compliance, provides a very practical model. It is comparatively lean and provides results of sufficient accuracy in the whole application range. KW - beam-model KW - commercial vehicles KW - design kinematics KW - five-Link model KW - Leaf spring suspension KW - vehicle dynamics Y1 - 2021 U6 - https://doi.org/10.1080/00423114.2021.1928249 VL - 60 IS - 8 SP - 2871 EP - 2889 PB - Taylor&Francis ER - TY - JOUR A1 - Keiner, Dominik A1 - Ram, Manish A1 - Barbosa, Larissa de Souza Noel Simas A1 - Bogdanov, Dmitrii A1 - Breyer, Christian T1 - Cost optimal self-consumption of PV prosumers with stationary batteries, heat pumps, thermal energy storage and electric vehicles across the world up to 2050 JF - Solar Energy N2 - Globally, PV prosumers account for a significant share of the total installed solar PV capacity, which is a growing trend with ever-increasing retail electricity prices. Further propelled by performance improvements of solar PV and innovations that allow for greater consumer choice, with additional benefits such as cost reductions and availability of incentives. PV prosumers may be one of the most important enablers of the energy transition. PV prosumers are set to gain the most by maximising self-consumption, while avoiding large amounts of excess electricity being fed into the grid. Additionally, electricity and heat storage technologies, heat pumps and battery electric vehicles are complementary to achieve the highest possible self-consumption shares for residential PV prosumer systems, which can reach grid-parity within this decade in most regions of the world. This research finds the cost optimal mix of the various complementary technologies such as batteries, electric vehicles, heat pumps and thermal heat storage for PV prosumers across the world by exploring 4 different scenarios. Furthermore, the research presents the threshold for economical maximum battery capacity per installed PV capacity, along with self-consumption ratios, demand cover ratios and heat cover ratios for 145 different regions across the world. This is a first of its kind study to conduct a global analysis of PV prosumers with a range of options to meet their complete energy demand from a future perspective, up to 2050. Maximising self-consumption from solar PV generation to meet all energy needs will be the most economical option in the future, for households across most regions of the world. KW - Battery KW - Electric vehicle KW - EMISSIONS KW - Heat pump KW - LIFE-CYCLE COST KW - Optimization KW - Photovoltaics KW - POWER-TO-HEAT KW - Prosumer KW - RESIDENTIAL HEAT KW - SYSTEMS KW - TECHNOLOGIES KW - Thermal energy storage KW - Vehicle-to-home Y1 - 2019 U6 - https://doi.org/10.1016/j.solener.2019.04.081 VL - 185 SP - 406 EP - 423 PB - Elsevier ER - TY - JOUR A1 - Kahl, Matthias A1 - Krause, Veronika A1 - Hackenberg, Rudolf A1 - Ul Haq, Anwar A1 - Horn, Anton A1 - Jacobsen, Hans-Arno A1 - Kriechbaumer, Thomas A1 - Petzenhauser, Michael A1 - Shamonin (Chamonine), Mikhail A1 - Udalzow, Anton T1 - Measurement system and dataset for in-depth analysis of appliance energy consumption in industrial environment JF - tm - Technisches Messen N2 - To support a rational and efficient use of electrical energy in residential and industrial environments, Non-Intrusive Load Monitoring (NILM) provides several techniques to identify state and power consumption profiles of connected appliances. Design requirements for such systems include a low hardware and installations costs for residential, reliability and high-availability for industrial purposes, while keeping invasive interventions into the electrical infrastructure to a minimum. This work introduces a reference hardware setup that allows an in depth analysis of electrical energy consumption in industrial environments. To identify appliances and their consumption profile, appropriate identification algorithms are developed by the NILM community. To enable an evaluation of these algorithms on industrial appliances, we introduce the Laboratory-measured IndustriaL Appliance Characteristics (LILAC) dataset: 1302 measurements from one, two, and three concurrently running appliances of 15 appliance types, measured with the introduced testbed. To allow in-depth appliance consumption analysis, measurements were carried out with a sampling rate of 50 kHz and 16-bit amplitude resolution for voltage and current signals. We show in experiments that signal signatures, contained in the measurement data, allows one to distinguish the single measured electrical appliances with a baseline machine learning approach of nearly 100% accuracy. KW - appliance monitoring KW - DAQ KW - NILM Y1 - 2019 U6 - https://doi.org/10.1515/teme-2018-0038 VL - 86 IS - 1 SP - 1 EP - 13 PB - De Gruyter ER - TY - JOUR A1 - Mikhaeil, Makram A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - On the application of adsorber plate heat exchangers in thermally driven chillers BT - An experimental and analytical study JF - Applied Thermal Engineering N2 - 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. Y1 - 2023 U6 - https://doi.org/10.1016/j.applthermaleng.2022.119713 VL - 220 PB - Elsevier ER - TY - JOUR A1 - Vérez, David A1 - Borri, Emiliano A1 - Crespo, Alicia A1 - Zsembinszki, Gabriel A1 - Dawoud, Belal A1 - Cabeza, Luisa F. T1 - Experimental Study of a Small-Size Vacuum Insulated Water Tank for Building Applications JF - Sustainability N2 - Insulation of thermal energy storage tanks is fundamental to reduce heat losses and to achieve high energy storage efficiency. Although water tanks were extensively studied in the literature, the enhancement of the insulation quality is often overlooked. The use of vacuum insulation has the potential to significantly reduce heat losses without affecting the dimension of the storage system. This paper shows for the first time the results of the heat losses tests done for a 0.535 m3 water tank for residential building applications built with a double wall vacuum insulation. The different tests show that the rate of heat losses strictly depends on the temperature distribution inside the tank at the beginning of the experiment. Compared to a conventional water tank insulated with conventional materials, the U-value of the lateral surface was reduced by almost three times (from 1.05 W/K·m2 to 0.38 W/K·m2) using vacuum insulation. However, the bottom part, which is usually used to place the support parts and the piping, is the critical design part of those tanks acting as a thermal bridge with the ambient and enhancing heat losses. Y1 - 2021 U6 - https://doi.org/10.3390/su13105329 VL - 13 IS - 10 SP - 1 EP - 11 PB - MDPI CY - Basel ER - TY - CHAP A1 - Schiedermeier, Maximilian A1 - Rettner, Cornelius A1 - Steiner, Marcel A1 - März, Martin T1 - Dual-inverter control synchronization strategy to minimize the DC-link capacitor current T2 - 2020 IEEE Vehicle Power and Propulsion Conference (VPPC), 18 November 2020 - 16 December 2020, Gijon, Spain N2 - 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. KW - Axles KW - Capacitors KW - Complexity theory KW - DC-link capacitor KW - Dual-inverter KW - interleaved inverters KW - Inverters KW - space vector modulation (SVM) KW - Switches KW - Synchronization KW - Voltage source inverter (VSI) KW - Wheels Y1 - 2020 U6 - https://doi.org/10.1109/VPPC49601.2020.9330921 SP - 1 EP - 6 PB - IEEE ER - TY - CHAP A1 - De, Sangita A1 - Niklas, Michael A1 - Mottok, Jürgen A1 - Brada, Přemek T1 - A Semantic Analysis of Interface Description Models of Heterogeneous Vehicle Application Frameworks: An Approach Towards Synergy Exploration T2 - MODELSWARD 2019: Proceedings of the 7th International Conference on Model-Driven Engineering and Software Development, 20.02.2019 - 22.02.2019, Prague, Czech Republic N2 - 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. KW - Application: Framework KW - IDL KW - Semantic: Mapping Y1 - 2019 SN - 978-989-758-358-2 SP - 394 EP - 401 PB - SCITEPRESS ER - TY - CHAP A1 - Reindl, Andrea A1 - Meier, Hans A1 - Niemetz, Michael A1 - Park, Sangyoung T1 - Decentralized Battery Management System with Customized Hardware Components T2 - IEEE 19th Student Conference on Research and Development (SCOReD), Sustainable Engineering and Technology towards Industry Revolution: 23-25 Nov. 2021, Kota Kinabalu, Malaysia N2 - 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. KW - battery fitness KW - Battery management system KW - Battery management systems KW - bidirectional power flow KW - Computer architecture KW - Costs KW - DC-DC power converters KW - decentralized control KW - Electric vehicles KW - Hardware KW - load sharing KW - Microprocessors KW - Renewable energy sources KW - second life battery Y1 - 2021 U6 - https://doi.org/10.1109/SCOReD53546.2021.9652737 SP - 350 EP - 355 PB - IEEE ER - TY - CHAP A1 - Hopkins, Andrew A1 - Hopfensperger, Bernhard A1 - Mellor, Phil T1 - DC-link Capacitor Reduction in Low Voltage and High Power Integrated Modular Motor Drives T2 - 2019 IEEE Energy Conversion Congress and Exposition (ECCE), 29 Sept.-3 Oct. 2019, Baltimore, MD, USA N2 - 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. KW - Capacitors KW - carrier phase shift KW - DC-link capacitor KW - dual 3-phase inverter KW - integrated modular motor drive KW - Interleaving KW - Inverters KW - Low voltage KW - Motor drives KW - Pulse width modulation KW - ripple current reduction KW - winding displacement KW - Windings Y1 - 2019 U6 - https://doi.org/10.1109/ECCE.2019.8913213 SP - 3208 EP - 3214 ER - TY - JOUR A1 - Sýkora, Miroslav A1 - Holicky, Milan A1 - Jung, Karel A1 - Diamantidis, Dimitris T1 - Human safety criteria for risk-based structural design JF - International Journal of Safety and Security Engineering N2 - 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 KW - individual risk KW - group risk KW - human safety KW - Life Quality Index KW - railway KW - risk acceptance KW - structure KW - target reliability Y1 - 2018 U6 - https://doi.org/10.2495/SAFE-V8-N2-287-298 VL - 8 IS - 2 SP - 287 EP - 298 PB - WIT Press ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav A1 - Bertacca, Elena T1 - Obsolescence Rate: Framework, Analysis and Influence on Risk Acceptance Criteria T2 - 6th International Symposium on Life-Cycle Civil Engineering (IALCCE), Ghent, Belgium N2 - 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. Y1 - 2018 UR - https://www.researchgate.net/publication/328578867_Obsolescence_Rate_Framework_Analysis_and_Influence_on_Risk_Acceptance_Criteria ER - TY - CHAP A1 - Briem, Ulrich ED - Scholten, Jan T1 - Neue Methode zur Bestimmung der Biegesteifigkeit von Drahtseilen T2 - Der Kran - Leistungssteigerung, Leichtbau und Automatisierung : 27. Internationale Kranfachtagung 2019 : Begleitband zur Kranfachtagung am 07. März 2019 in Bochum Y1 - 2019 SN - 3-89194-226-5 SP - 103 EP - 112 PB - Selbstverlag der Ruhr-Universität Bochum CY - Bochum ER - TY - CHAP A1 - Carrillo Li, Enrique Roberto A1 - Schorr, Philipp A1 - Kaufhold, Tobias A1 - Rodríguez Hernández, Jorge Antonio A1 - Zentner, Lena A1 - Zimmermann, Klaus A1 - Böhm, Valter ED - Awrejcewicz, Jan ED - Kaźmierczak, Markek ED - Olejnik, Paweł T1 - Kinematic analysis of the rolling locomotion of mobile robots based on tensegrity structures with spatially curved compressed components T2 - Applicable Solutions in Non-Linear Dynamical Systems; 15th International Conference "Dynamical Systems - Theory and Applications" (DSTA 2019, 2-5 December, 2019, Lodz, Poland N2 - 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. KW - Inverse kinematics KW - Nonholonomic mechanics KW - Tensegrity structure Y1 - 2019 UR - http://212.191.87.54:1616/k16/awrejcewicz/publikacje/T2.pdf SN - 978-83-66287-30-3 SP - 335 EP - 344 PB - Wydawnictwo Politechniki Łódzkiej CY - Łódź, Polen ER - TY - CHAP A1 - Briem, Ulrich T1 - Lebensdauerverhalten verdichteter Seildrähte T2 - Ilmenauer Drahttag 2019 Y1 - 2019 SN - 978-3- 938843-96-3 SP - 73 EP - 82 PB - ISLE Steuerungstechnik und Leistungselektronik CY - Ilmenau ER - TY - JOUR A1 - Kurzweil, Peter A1 - Shamonin (Chamonine), Mikhail T1 - State-of-Charge Monitoring by Impedance Spectroscopy during Long-Term Self-Discharge of Supercapacitors and Lithium-Ion Batteries JF - Batteries N2 - 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. KW - aging KW - capacitance KW - self-discharge KW - state-of-charge monitoring KW - supercapacitor Y1 - 2018 U6 - https://doi.org/10.3390/batteries4030035 VL - 4 IS - 3 SP - 1 EP - 13 PB - MPDI ER -