Determination and characterization of the influences of the bike frame on eBike drive units as the basis for their design and optimization. - In: Neunte IFToMM D-A-CH Konferenz 2023, (2023), S. 1-7
In this paper, the influence of the bike frame on the loading of the eBike drive unit is determined. For this purpose, relevant load cases and boundary conditions are derived based on the existing norms for the individual consideration of the frame and the drive. In this context, external loads on the frame and the forces acting on the engine must be taken into account. The following simulative study shows that the bike frame has an enormous and load-dependent influence on the load situation of the frame interface and the stresses within the housing of the drive unit. In general, this influence can be explained by the stiffness of the frame construction. Altogether, these results show that the design of the eBike drive unit according to its current standard requirements is not sufficient to cover these enormous influences of the bike frame.
https://doi.org/10.17185/duepublico/77395
Characterization and alignment of the flexure mechanism for the new Kibble balance at NIST. - In: ASPE Annual Meeting 2022, (2023), S. 80-84
TMS and fMRI-based localization of the attention network. - In: Brain stimulation, ISSN 1876-4754, Bd. 16 (2023), 1, S. 291-292
Richtiger Name des 4. Verfassers: Jens Haueisen
https://doi.org/10.1016/j.brs.2023.01.517
Closed-loop robotic TMS motor mapping using an online-optimized sampling scheme. - In: Brain stimulation, ISSN 1876-4754, Bd. 16 (2023), 1, S. 320
https://doi.org/10.1016/j.brs.2023.01.593
Fill level measurements using an M-sequence UWB radar. - In: International journal of microwave and wireless technologies, ISSN 1759-0795, Bd. 15 (2023), 1, S. 74-81
Due to increasingly complex and automated manufacturing processes, the demands on the control parameters of these processes are also increasing. In many applications, such a parameter is the fill quantity, whose precise determination is of ever growing importance. This paper shows with which accuracy and precision an M-sequence ultra-wideband radar can determine levels in small metallic and non-metallic containers with contact-based and contactless measurements. First, the principle of level measurement using guided wave radar is explained and the measurement setup is described. Afterward, the measurement results are shown and discussed. The measurements show that the level can be measured with an accuracy of better than 0.5 mm. In addition, level fluctuations can be detected with a precision of 3 μm. Based on the results of the guided wave radar, the possibilities of volumetric contactless measurement using an electrically small patch antenna are discussed. A particular challenge in contactless level measurement is the high number of multipath components, which strongly influence the accuracy. In addition, there are near-field effects when measuring close to the antenna. Exploiting these near-field effects, an additional method to accurately determine the full state of the container is investigated.
https://doi.org/10.1017/S1759078722000502
Model signatures for design and usage of simulation-capable model networks in MBSE. - In: Product lifecycle management, (2023), S. 155-164
Product development is characterised by numerous synthesis and analysis loops. Analysis provides information on the fulfillment of the required properties of the system under development. Analysis results therefore are an important basis for further synthesis steps. In the context of Model-Based Systems Engineering (MBSE), different types of simulation models play an important role. The overall system (product) can be broken down to system elements. For each system element a set of models has to be established, that provides the required degrees of fidelity, representations of system properties, flows, etc. reflecting the variety of modelling purposes. These models have to be integrated horizontally (same system level along the relevant flows of material, energy, and information) and vertically (aggregation from subsystem level to the overall system level, refinement in the opposite direction) to create a holistic model-based system representation. An important and challenging task is to identify and shape relevant subsystem models. In order to define an appropriate structure of these models, model developers may utilize criteria like selected properties of system elements and interrelations, their degree of detail or modelling assumptions. The relevant criteria have to be made transparent. For this purpose, the paper discusses the concept of model signatures that contain relevant meta information about each single model of all system elements, subsystems up to models of the overall system. This standardized meta information enables an identification and selection of those models and the decision on the necessary model integration. The concept is discussed on the basis of a roller bearing as an example out of an electro-mechanical drivetrain. A potential analysis provides information about the possible usage of the model signatures concept.
https://doi.org/10.1007/978-3-031-25182-5_16
Steep resonance of parametrically excited active MEMS cantilevers for dynamic mode in Atomic Force Microscopy. - In: Proceedings in applied mathematics and mechanics, ISSN 1617-7061, Bd. 22 (2023), 1, e202200230, S. 1-6
Ongoing developments in nanotechnology demand higher spatial resolution and thus, higher amplitude sensitivity in Atomic Force Microscopy (AFM). In this work, active cantilevers with integrated sensor and actuator systems are parametrically excited using a novel, analog feedback circuit. With that it is possible to adapt the strength and sign of a cubic nonlinearity which provides a bound to the amplitudes in resonance operation. The system response shows steeper resonance curves and therefore higher amplitude sensitivities compared to forced excited cantilevers. Theoretical findings are validated experimentally.
https://doi.org/10.1002/pamm.202200230
Photon-induced near-field interaction in ultrafast low energy electron microscopy. - [Washington, D.C., USA] : Optica Publishing Group. - 1 Online-Ressource (Paper Tu3A.5)
We report the first observation of optical near-field coupling to an ultrafast wavepacket of free, low-energy electrons. Transient optical near-fields, highly spatially confined around a nanometer-sized Yagi-Uda-antenna are probed in a point-projection-microscope with 30-fs resolution.
https://doi.org/10.1364/UP.2022.Tu3A.5
Monitoring considerations of second life lithium ion batteries in battery energy storage systems. - In: PCIM Europe 2022, (2022), S. 1905-1914
This paper presents an analytical study of the most important technical aspects that should be considered in the methodologies for monitoring second-life lithium-ion batteries in stationary energy storage systems. The study is based, on one hand, on the specificity of these batteries in terms of changing their response differently in the second-life than in the first to external and operational influences. On the other hand, it is based on the monitoring requirements of storage systems to obtain an improved monitoring system with sufficient accuracy and more efficient performance of batteries in their second-life.
https://doi.org/10.30420/565822263
Incorporating state of charge estimation methods towards more accurate monitoring of second-life lithium-ion batteries. - In: 2022 13th International Renewable Energy Congress (IREC), (2022), insges. 6 S.
Although several methods are developed for estimating the state of charge of lithium-ion batteries, there is still a challenge regarding monitoring the second life of these batteries due to the expected difference in the behavior and operating conditions in their second life. Considering that each method has its advantages and disadvantages according to the application and operating conditions, and monitoring the batteries in their second life is of special importance because it is required to integrate with the battery management system to balance cells, diagnose faults and prevent overheating. Therefore, the estimation method developed in this study, by incorporating artificial neural network method and Kalman filter method with fine-tuning of the filtering process using Coulomb counting, provides a solution for more accurate online monitoring of these batteries. Aiming to get the best possible performance, considering the specificity of the second life of the batteries in terms of operating voltage, low values of expected capacity, discharge ratio and other operational parameters.
https://doi.org/10.1109/IREC56325.2022.10002052