TY - CHAP A1 - von Hoffmann, Alexander T1 - Analysis of Adaptive Light Distributions with AFSim T2 - PROCEEDINGS OF PAL 2001 - PROGRESS IN AUTOMOBILE LIGHTING, HELD LABORATORY OF LIGHTING TECHNOLOGY, SEPTEMBER 2001. VOL 9 N2 - European car manufacturers, setmakers and research institutes have worked for about 10 years on Adaptive Frontlighting Systems (AFS). Due to the fact that an AFS is no longer a single part of the car, it will have to be regarded in systems context with sensor and control devices resulting in a rising complexity. In order to increase safety in nighttime traffic, the light distribution should improve the visibility of objects such as delineation lines. On the other hand, glare levels for other traffic participants shall be less or equal to those of conventional headlights. This paper presents requirements for simulation software derived from measurements of the glare illuminance E. For the covering abstract see ITRD E123380. KW - Light Simulation KW - Automotive Lighting KW - AFS Y1 - 2001 SN - 3-89675-971-X PB - Herbert-Utz-Verlag CY - München ER - TY - CHAP A1 - von Hoffmann, Alexander T1 - Evaluation of Adaptive Light Distributions with AFSim T2 - SAE Technical Paper Series N2 - European car manufacturers, setmakers and research institutes have been working for the last decade on Adaptive Frontlighting Systems (AFS). Due to the fact, that an AFS is no longer a single part of the car, it will have to be regarded in systems context with sensor and control devices resulting in a rising complexity. In order to help the engineer in developing an AFS, the software-tool AFSim has been programmed providing functions to swivel and to dim the light-distribution of a headlight on a freely programmable road with curves. The software package AFSim has been recently expanded with further functions facing the range of a headlight. KW - Suppliers ; Logistics ; Headlamps ; Research and development ; Computer software and hardware ; Sensors and actuators Y1 - 2001 U6 - https://doi.org/10.4271/2001-01-0303 SN - 0148-7191 PB - SAE International CY - Warrendale, PA, United States ER - TY - GEN A1 - von Hoffmann, Alexander T1 - Limits of Light Measurement Y1 - 2004 ER - TY - GEN A1 - von Hoffmann, Alexander T1 - Simulations, status and future trends Y1 - 2013 UR - https://issuu.com/salomon.berner/docs/dvn_2013_us_workshop_booklet-final ER - TY - JOUR A1 - Kravchuk, Oleksandr A1 - Grunewald, Kristina A1 - Bahr, Joachim A1 - Hofmann, Florian A1 - Reichenberger, Marcus T1 - Production of Miniaturized Sensor Structures on Polymer Substrates Using Inkjet Printing JF - Advanced Materials Research N2 - Strain sensors based on the resistive principle have been developed and produced by inkjet printing. Depending on the surface conditions of the substrates and the properties of the silver inks, with adequate densification of the printed nanoparticle containing structures, gauge factors of around 2.6, dimensions of 6.7 mm × 6.4 mm and grid line widths of around 90 μm, have been achieved with silver inks. Performance tests including up to 120 mechanical deformation cycles have been successfully carried out. Y1 - 2014 U6 - https://doi.org/10.4028/www.scientific.net/AMR.1038.49 SN - 1662-8985 VL - 1038 SP - 49 EP - 55 PB - Trans Tech Publications, Ltd. ER - TY - CHAP A1 - Wagner, Bernhard A1 - Köhler, Stefan A1 - Endres, Stefan A1 - Seßler, Christoph T1 - CoFAT 2016 - Lyapunov-Based Nonlinear Observer Design for an Inductively Supplied Saturated Excitation Coil of an Externally Excited Synchronous Machine N2 - An inductive energy transfer system (IETS) for the energy supply of the excitation coil of an externally excited synchronous machine (EESM) has been developed. Due to the removal of the slip rings, it is impossible to measure the excitation current and the rotor resistance on the rotating rotor. Therefore, a nonlinear observer for the EESM with IETS is presented, which estimates the excitation current and the rotor resistance. This observer is designed with the direct method of Lyapunov. Keywords—externally excited synchronous machine; electric mobility; drive control; inductive energy transfer; direct method of Lyapunov; nonlinear observer Y1 - 2016 VL - 2016 ER - TY - CHAP A1 - Ruccius, Benjamin A1 - Preller, Bastian A1 - Marz, Martin A1 - Wagner, Bernhard T1 - An advanced control concept for modular multilevel converter using capacitor voltage estimation T2 - 2017 IEEE Southern Power Electronics Conference (SPEC) N2 - An advanced control concept for a Modular Multilevel Converter (MMC) is presented in this paper. By using a Notch Filter and a Kalman Filter it is possible to reduce unwanted AC components within circulating currents in the MMC significantly. Subsequently the current stress and the conduction and switching losses in the semiconductors can be minimized. In the second part of this paper, approaches to estimate the capacitor voltages are presented. The observability is inverstigated theoretically and via simulations. A disadvantage of the MMC topology is the need of a complex and expensive communication system. While the submodule voltages are being estimated, the communication effort between the submodules and the main controller hardware is significantly reduced. KW - Control theory , DC-AC Power Converters , Kalman Filter , Modular Multilevel Converter , Notch Filter Y1 - 2018 U6 - https://doi.org/10.1109/SPEC.2017.8333590 PB - IEEE ER - TY - CHAP A1 - Kohler, Stefan A1 - Wagner, Bernhard T1 - Control of the excitation current of an externally excited synchronous machine supplied by an inductive energy transfer system T2 - 2018 Thirteenth International Conference on Ecological Vehicles and Renewable Energies (EVER) N2 - A method for the control of the excitation current of an externally excited synchronous machine supplied by an inductive energy transfer system is presented. The input-output linearization and the trajectory planning enable an exact match of planned and real signals in the absence of disturbances. KW - externally excited synchronous machine , electric mobility , drive control , trajectory planning , input-output linearization , inductive energy transfer Y1 - 2018 U6 - https://doi.org/10.1109/EVER.2018.8362358 SP - 1 EP - 8 PB - IEEE ER - TY - CHAP A1 - Wendel, Sebastian A1 - Geiger, Andreas A1 - Liegmann, Eyke A1 - Arancibia, David A1 - Duran, Esteban A1 - Kreppel, Thomas A1 - Rojas, Felix A1 - Popp-Nowak, Flaviu A1 - Diaz, Matias A1 - Dietz, Armin A1 - Kennel, Ralph A1 - Wagner, Bernhard T1 - UltraZohm - a Powerful Real-Time Computation Platform for MPC and Multi-Level Inverters T2 - 2019 IEEE International Symposium on Predictive Control of Electrical Drives and Power Electronics (PRECEDE) N2 - This paper presents the hardware design, software architecture and workflow for rapid control prototyping intended for a wide-range of power electronics based systems. The proposed system is especially useful for computationally intensive algorithms and applications with high demands on the number of required measurements and gate signals. The focus is on a heterogeneous system architecture with minimized latency and jitter as well as a high signal integrity. The software architecture enables a simple, fast and performance driven implementation. A combination of carrier board and exchangeable interfacing adapter boards allows to control a wide range of power electronics applications and converters, i.e., starting with a single switching device, converters with one or several voltage levels and one or several phase legs, up to large modular multilevel converters for grid-tied connection or variable speed drives. KW - Real-time system , control platform , model predictive control , modular multilevel converter , Zynq , SoC FPGA , UltraScale + , heterogeneous system architecture , low latency , low jitter , high signal integrity , power electronics Y1 - 2019 U6 - https://doi.org/10.1109/PRECEDE.2019.8753306 PB - IEEE ER - TY - GEN A1 - Harms, Patrick T1 - Automated Usability Evaluation of Virtual Reality Applications T2 - ACM Transactions on Computer-Human Interaction (TOCHI) N2 - Virtual reality (VR) and VR applications have reached the end-user and, hence, the demands on usability, also for novel applications, have increased. This situation requires VR usability evaluation methods that can be applied quickly, even after a first release of an application. In this article, we describe such an approach, which is fully automated and does not ask users to perform predefined tasks in a fixed test setting. Instead, it works on recordings of the actual usage of a VR application from which it generates task trees. Afterwards, it analyzes these task trees to search for usability smells, i.e., user behavior indicating usability issues. Our approach provides detailed descriptions of the usability issues that have been found and how they can be solved. We performed a large case study to evaluate our approach and show that it is capable of correctly identifying usability issues. Although our approach is applicable for different VR interaction modalities, such as gaze, controller, or hand interaction, it also has limitations. For example, it can detect diverse issues related to user efficiency, but specific misunderstandings of users cannot be uncovered. Y1 - 2019 U6 - https://doi.org/10.1145/3301423 VL - 26 IS - 3 ER - TY - JOUR A1 - Herbold, Steffen A1 - Trautsch, Fabian A1 - Harms, Patrick A1 - Herbold, Verena A1 - Grabowski, Jens T1 - Experiences With Replicable Experiments and Replication Kits for Software Engineering Research JF - Advances in Computers N2 - Replications and replicable research are currently gaining traction in the software engineering research community. Our research group made an effort in the recent years to make our own research accessible for other researchers, through the provision of replication kits that allow rerunning our experiments. Within this chapter, we present our experiences with replication kits. We first had to learn which contents are required, how to structure them, how to document them, and also how to best share them with other researchers. While this sounds very straightforward, there are many small potential mistakes, which may have a strong negative impact on the usefulness and long-term availability of replication kits. We derive best practices for the content and the sharing of replication kits based on our experiences. Moreover, we outline how platforms for replicable research may further help our community, especially with problems related to the external validity of results. Finally, we discuss the lack of integration of replication kits into most current review processes at conferences and journals. We also give one example for a review process into which replication kits were well-integrated. Altogether, this chapter demonstrates that making research replicable is a challenging task and there is a long road ahead until our community has a generally accepted and enforced standard of replicability. Y1 - 2019 U6 - https://doi.org/10.1016/bs.adcom.2018.10.003 VL - 113 PB - Elsevier ER - TY - CHAP A1 - Harms, Patrick T1 - VR Interaction Modalities for the Evaluation of Technical Device Prototypes T2 - Human-Computer-Interaction - INTERACT 2019 N2 - Virtual Reality (VR) systems have reached the consumer market which offers new application areas. In our paper, we examine to what extent current VR technology can be used to perform local or remote usability tests for technical devices, e.g., coffee machines. For this, we put virtual prototypes of the technical devices into VR and let users interact with them. We implemented four interaction modalities that are suitable for low-level smartphone-based VR systems up to high fidelity, tethered systems with room-scale tracking. The modalities range from a simple gaze pointer to interaction with virtual hands. Our case study and its counter evaluation show that we are able to detect usability issues of technical devices based on their virtual prototypes in VR. However, the quality of the results depends on the matching between the task, the technical device, the prototype level, and the interaction modality. Y1 - 2019 U6 - https://doi.org/10.1007/978-3-030-29390-1_23 ER - TY - CHAP A1 - Gleichauf, Johanna A1 - Vollet, Johannes A1 - Pfitzner, Christian A1 - Koch, Philipp A1 - May, Stefan T1 - Sensor Fusion Approach for an Autonomous Shunting Locomotive BT - Conference paper T2 - Informatics in Control, Automation and Robotics N2 - In order to allow robust obstacle detection for autonomous freight traffic using freight trains or shunting locomotives, several different sensors are required. Humans and other objects must be detected so that the vehicle can stop in time. Laser scanners deliver distance information and are popular in robotics and automation. Cameras deliver further pieces of information on the environment and are especially useful for the classification of objects, but do not deliver distance measurements. Thermal cameras are ideal for the detection of humans based on their body temperature if the surrounding temperature is not too similar. It is only the combination of these different sensors which delivers enough robustness. Therefore a sensor fusion and an extrinsic calibration has to take place. This article presents an approach fusing a 2D and an 8-layer 3D laser scanner with a thermal and a Red-Green-Blue (RGB) camera, using a triangular calibration target taking all six degrees of freedom into account. The calibration was tested and the results validated during reference measurements and autonomous and manually controlled field tests. This sensor fusion approach was used for the obstacle detection of an autonomous shunting locomotive. KW - Sensor fusion KW - Extrinsic calibration KW - Object detection KW - Autonomous shunting locomotive Y1 - 2019 SN - 9783030112912 U6 - https://doi.org/10.1007/978-3-030-11292-9_30 SN - 1876-1100 SP - 603 EP - 624 PB - Springer International Publishing CY - Cham ER - TY - CHAP A1 - Ruccius, Benjamin A1 - Kraus, T. A1 - Westermann, R. A1 - Heckel, Thomas A1 - Marz, Martin A1 - Wagner, Bernhard T1 - A Cascaded Control Concept for Modular Multilevel Converters with Capacitor Voltage Estimation using a Kalman Filter T2 - 2019 10th International Conference on Power Electronics and ECCE Asia (ICPE 2019 - ECCE Asia) N2 - An approach to estimate the submodule capacitor voltages in a Modular Multilevel Converter (MMC) is presented and realized in a hardware test setup. One disadvantage of the MMC topology is the high communication and measurement effort. As the submodule voltages are being estimated, the measurement effort as well as the communication effort between the submodules and the main controller hardware is significantly reduced. Thereby, the reliability of the system also increases. In the hardware test setup, it is verified that using a notch filter in the feedback path of the energy control loop significantly decreases unwanted AC components of the circulating currents within the MMC. Subsequently the current stress as well as the conduction and switching losses in the semiconductors can be minimized. Furthermore, the dynamic performance of the capacitor voltage estimation and control scheme was analyzed via hardware tests. KW - Control Theory, Kalman Filters, Modular Multilevel Converters, Notch Filters Y1 - 2019 U6 - https://doi.org/10.23919/ICPE2019-ECCEAsia42246.2019.8796897 PB - IEEE ER - TY - JOUR A1 - Dietz, Armin A1 - Di Tommaso, Antonino Oscar A1 - Marignetti, Fabrizio A1 - Miceli, Rosario A1 - Nevoloso, Claudio T1 - Enhanced Flexible Algorithm for the Optimization of Slot Filling Factors in Electrical Machines JF - Energies N2 - The continuous development in the field of industrial automation and electric mobility has led to the need for more efficient electrical machines with a high power density. The improvement of electrical machines’ slot filling factors is one of the measures to satisfy these requirements. In recent years, this topic has aroused greater interest in the industrial sector, since the evolution of the winding technological manufacturing processes allows an economically sustainable realization of ordered winding arrangements, rather than random ones. Moreover, the manufacture of electrical machines’ windings must be preceded by an accurate design phase in which it is possible to evaluate the maximum slot filling factor obtainable for a given wire shape and for its dimensions. For this purpose, this paper presents an algorithmic approach for the evaluation of maximum slot filling factors in electrical machines under an ideal geometric premise. In particular, this algorithm has a greater degree of flexibility with respect to the algorithm approaches found in the literature, since the study has been extended to round, rectangular and hexagonal wire sections. Furthermore, the slot filling factor calculation was carried out both for standard and non-standard slots. The algorithmic approach proposed can be considered as an additional useful tool for the fast design of electrical machine windings. KW - electrical motors; sot filling factor; optimization algorithm; windings; magnetic wire; filling factor optimization Y1 - 2020 U6 - https://doi.org/10.3390/en13051041 SN - 1996-1073 VL - 13 IS - 5 PB - MDPI AG ER - TY - CHAP A1 - Gerstner, Michael A1 - Maerz, Martin A1 - Dietz, Armin T1 - Design of a Wide Input Voltage Range Current-Fed DC/DC Converter Within a Reduced Duty-Cycle Range T2 - 2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe) N2 - A design of a current-fed push-pull converter for wide input voltage ranges within a reduced duty-cycle range is presented. Based on the converter conversion ratios of three different clamping configurations, the potential of the input clamping is shown analytical, simulative and by measurements. A differentiation is made between the four possible operating modes, which can be distinguished in the control of the semiconductors and the magnetomotive force in the reactor. By optimizing the turn ratios of both transformers, the wide input voltage range capability of the input clamped current-fed push-pull converter was improved, which has been proved by measurements on a real prototype. KW - DC power supply ; Design ; Converter circuit ; Measurement ; Power Supply Y1 - 2020 U6 - https://doi.org/10.23919/epe20ecceeurope43536.2020.9215825 PB - IEEE ER - TY - CHAP A1 - Rabenstein, Lukas A1 - Dietz, Armin A1 - Parspour, Nejila T1 - Design Concept of a Wound Field Transverse Flux Machine using Soft Magnetic Composite Claw-Poles T2 - 2020 10th International Electric Drives Production Conference (EDPC) N2 - This paper presents the machine concept of a wound field transverse flux machine (WFTFM). In contrast to permanent magnet transverse flux machines (PMTFM), here the magneto motive force (mmf) of the rotor is generated by a current. The magnetic circuit of the WFTFM is made of soft magnetic composite (SMC) and is designed as claw-poles. Thus the magnetic circuit consists of only a few components. Together with the simple ring coils in stator and rotor, the WFTFM offers advantages in the production of electrical machines. The basic structure of the machine and a first design is described here. The results generated by numerical three-dimensional finite element analysis (FEA) are compared with those of conventional machines. Y1 - 2021 U6 - https://doi.org/10.1109/edpc51184.2020.9388176 PB - IEEE ER - TY - JOUR A1 - Shibelgut, Alexander A. A1 - Konkin, Dmitry A. A1 - Litvinov, Rudolph Victorovich A1 - Kruglov, Roman A1 - Bunge, Christian-Alexander A1 - Poisel, Hans T1 - Scattering Into Guided Modes Due to Imperfect Graded-Index Structure in Polymer Optical Fibers JF - Journal of Lightwave Technology N2 - Rayleigh scattering in graded-index polymer optical fibers (GI-POF) is studied under the assumption that spherical scatterers are uniformly distributed within the layers of concentric ring structure. This approximation allows to describe typical imperfections occurring during the fabrication of GI-POFs. For the purpose of experimental characterization by side illumination, an analytical model of the light conversion into waveguide modes has been developed. This model describes the mode excitation by a multiplicative contribution of three different physical mechanisms. The corresponding experimental analysis of the light scattering has been performed and compared with numerical simulation results for the fibers with single-ring and multi-ring structures. Besides the application to GI-POFs, this article can be also applied to multi-step index fibers. KW - Laser beams KW - Optical fibers KW - Polymers KW - Measurement by laser beam KW - Rayleigh scattering Y1 - 2020 U6 - https://doi.org/10.1109/JLT.2020.2970752 SN - 0733-8724 VL - 38 IS - 6 SP - 1454 EP - 1460 PB - Institute of Electrical and Electronics Engineers (IEEE) ER - TY - RPRT A1 - Dengler, Simon Andreas A1 - Fischer, Jakob A1 - Luber, Michael A1 - Lenkowski, Holger A1 - Schüßler, Christoph A1 - Carruth, Kevin A1 - Urbanek, Peter A1 - Ziemann, Olaf T1 - Power over POF – A Short Overview T2 - P2 Sensors and Measurement Systems for Physical Quantities N2 - There are various applications in high voltage, explosive or high electromagnetic interfered environments that require sensors with an electrical isolation from other components of a system. The basics of possible solution, based on optically powered sensor links, were shown previously. Because of different requirements for the applications, a variety of system approaches has been developed (available power for sensor purposes; length between the control node and the sensor; speed of transmitted data etc.). Key requirements and the current approaches will be discussed below. KW - remotely powered sensors KW - galvanic isolation KW - sensor networks KW - polymer optical fiber KW - power over fiber Y1 - 2020 SN - 978-3-9819376-2-6 U6 - https://doi.org/10.5162/SMSI2020/P2.15 VL - 2020 SP - 254 EP - 255 PB - AMA Service GmbH CY - Wunstorf ER - TY - CHAP A1 - Mai, Annette A1 - Wagner, Bernhard A1 - Streit, Fabian T1 - Elimination of Current Harmonics in Electrical Machines with Iterative Learning Control N2 - The magnitude of current harmonics depends on the design of an electrical machine. By suppressing these harmonics noise can be reduced and efficiency improved. Iterative Learning Control (ILC) has proven effective in reducing harmonics. One of the challenges of working with ILC is operation at varying speeds. Variable speeds are particularly important for applications like automotive drives. The ILC period length changes during the learning process at varying speeds. Due to fixed sample rates, the number of values processed by the ILC varies with motor speed.This paper proposes a method to solve this problem and uses ILC at varying speeds. The ILC used to eliminate the harmonics is based on the inverse system. The usage of a two-dimensional memory array is proposed. This data structure holds rows for specific speeds between which interpolation is performed, enabling the elimination of errors which are periodically cyclic to one electrical rotation. This includes the reduction of the motor current harmonics. To verify the presented method a permanent magnet synchronous motor with distinctive 5th and 7th harmonics is used. In real-time implementations, limitations of memory and computational capacity occur. KW - Iterative Learning Control, Repetitive Control, Current Harmonics, PMSM, Motor Control Y1 - 2020 U6 - https://doi.org/10.1109/EDPC51184.2020.9388177 VL - 2020 ER - TY - JOUR A1 - Weiland, J. A1 - Luber, M. A1 - Seewald, R. A1 - Schiebahn, A. A1 - Engelbrecht, Rainer A1 - Reisgen, U. T1 - Structural Health Monitoring of Adhesively Bonded Joints: Proposing a new Method by use of Polymer Optical Fibers JF - Procedia Structural Integrity N2 - According to the current state of the art, adhesively bonded joints cannot be tested completely non-destructively. This is the main motivation to permanently monitor adhesively bonded joints in order to record their structural integrity and - as a result - to ensure safe load transmission. By the use of permanent non-destructive Structural Health Monitoring (SHM) methods, structural damages in the adhesive bond can be detected at an early stage. This paper presents a new method for monitoring the structural integrity of adhesively bonded joints by integrating a Polymer Optical Fiber (POF) into the adhesive layer. The sensor concept is based on a deformation transfer from the adhesive to the POF, which results in a change in the cross-sectional shape of the POF. The cross-sectional shape influences the optical light propagation in the POF, which can be detected by simple optical measuring devices. The paper describes the general principle and first results of investigations on a structural adhesive (3M Scotch-Weld DP 609). The sensor signal is in a good relation to the stress state of the adhesive layer. KW - adhesive bonding structural health monitoring polymer optical fiber single lap joint Y1 - 2020 U6 - https://doi.org/10.1016/j.prostr.2020.11.106 SN - 2452-3216 VL - 28 SP - 1249 EP - 1257 PB - Elsevier BV ER - TY - CHAP A1 - Steinbrink, Marco A1 - Koch, Philipp A1 - May, Stefan A1 - Jung, Bernhard A1 - Schmidpeter, Michael T1 - State Machine for Arbitrary Robots for Exploration and Inspection Tasks T2 - Proceedings of the 2020 4th International Conference on Vision, Image and Signal Processing N2 - In this paper, a novel state machine for mobile robots is described that enables a direct use for exploration and inspection tasks. It offers a graphical user interface (GUI) to supervise the process and to issue commands if necessary. The state machine was developed for the open-source framework Robot Operating System (ROS) and can interface arbitrary algorithms for navigation and exploration. Interfaces to the commonly used ROS navigation stack and the explore_lite package are already included and can be utilized. In addition, routines for mapping and inspection can be added freely to adapt to the area of application. The state machine features a teleoperation mode to which it changes as soon as a respective command was issued. It also implements a software emergency stop and multiplexes all movement commands to the motor controller. To show the state machine's capabilities several simulations and real-world experiments are described in which it was used. KW - State Machine KW - Exploration KW - Inspection KW - Mobile Robotics Y1 - 2020 U6 - https://doi.org/10.1145/3448823.3448857 PB - ACM CY - New York, NY, USA ER - TY - CHAP A1 - Wendel, Sebastian A1 - Karamanakos, Petros A1 - Dietz, Armin A1 - Kennel, Ralph T1 - Flux Linkage-Based Model Predictive Current Control for Nonlinear PMSM Drives T2 - IECON 2020 The 46th Annual Conference of the IEEE Industrial Electronics Society N2 - In this paper, a flux linkage-based direct model predictive current control approach is presented for small permanent magnet synchronous motor (PMSM) drives. The method aims to minimize the current ripples at steady state by deciding on the optimal switching instant, while exhibiting fast dynamic behavior during transients. To this end, the future trajectory of the stator current is not computed based on the machine inductances or inductance look-up tables, but on the changes of the magnetic flux linkage by utilizing flux linkage maps. As shown, the proposed method can be particularly advantageous for electric drives with a noticeable nonlinearity in terms of saturation and/or cross-coupling effects since it allows for a significantly increased prediction accuracy, which leads to an improved steady-state performance as indicated by the reduced current distortions. KW - Couplings ; Switches; Predictive models ; Mathematical model ; Rotors ; Real-time systems ; Prediction algorithmso Y1 - 2022 U6 - https://doi.org/10.1109/iecon43393.2020.9254484 PB - IEEE ER - TY - CHAP A1 - Dietz, Armin A1 - Caruso, M. A1 - Di Tommaso, A. O. A1 - Miceli, R. A1 - Nevoloso, C. T1 - Enhanced Mathematical Modelling of Interior Permanent Magnet Synchronous Machine Considering Saturation, Cross-Coupling and Spatial Harmonics effects T2 - 2020 Fifteenth International Conference on Ecological Vehicles and Renewable Energies (EVER) N2 - The Interior Permanent Magnet Synchronous machine (IPMSM) conventional mathematical model is generally employed to investigate and simulate the IPMSM control and drive system behaviour. However, magnetic nonlinearities and spatial harmonics have a substantial influence on the IPMSM electromagnetic behaviour and performances. In order to simulate the IPMSM real electromagnetic behaviour, this paper describes an enhanced mathematical model that takes into account the saturation, cross-coupling and spatial harmonics effects. This model has been implemented in Matlab®/Simulink environment where the electric and magnetic parameters are derived from FEA investigations and implemented by the use of lookup tables. The high fidelity of the proposed IPMSM Simulink model is validated by the results of the FEA investigations carried out. KW - Finite Element Analysis (FEA); Interior Permanent Magnet Synchronous Machine (IPMSM); saturation; cross- coupling; spatial harmonics Y1 - 2020 U6 - https://doi.org/10.1109/ever48776.2020.9243003 PB - IEEE ER - TY - CHAP A1 - Schier, Michael A1 - Epple, Fabius A1 - Maaoui, Aicha A1 - Schwellinger, Martin A1 - Weber, Michael A1 - Dietz, Armin A1 - Zimmermann, Rolf T1 - Development of a Two In One Motor System as a new Vehicle Energy Concept for Next Generation Car T2 - 2020 Fifteenth International Conference on Ecological Vehicles and Renewable Energies (EVER) KW - Air conditioning;Electric potential;Biological system modeling;Production;Automobiles;Next generation networking;Engines Y1 - 2020 U6 - https://doi.org/10.1109/ever48776.2020.9243148 PB - IEEE ER - TY - CHAP A1 - Koch, Philipp A1 - Engelhardt, Helmut A1 - May, Stefan A1 - Schmidpeter, Michael A1 - Ziegler, Jasmin A1 - Nüchter, Andreas T1 - Signed Distance Based Reconstruction for Exploration and Change Detection in Underground Mining Disaster Prevention T2 - 2020 IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR) N2 - This publication describes an application of a Truncated Signed Distance Mapping approach for disaster intervention in underground mine shafts through geometrical change detection of the shaft walls. The paper describes two main problems of such an approach (aligning two potentially huge point clouds and automatic change detection by comparing the reconstructed volumes) and explains in detail the proposed solution. KW - signed distance KW - stereo camera KW - underground mining KW - change detection Y1 - 2020 U6 - https://doi.org/10.1109/SSRR50563.2020.9292618 SP - 360 EP - 365 PB - IEEE ER - TY - CHAP A1 - Dalferth, Jasmin A1 - Winkelmann, Sven A1 - Schwenker, Friedhelm T1 - Using Mask R-CNN for Image-Based Wear Classification of Solid Carbide Milling and Drilling Tools T2 - Artificial Neural Networks in Pattern Recognition N2 - In order to ensure high productivity and quality in industrial production, early identification of tool wear is needed. Within the context of Industry 4.0, we integrate wear monitoring of solid carbide milling and drilling cutters automatically into the production process. Therefore, we propose to analyze wear types with image instance segmentation using Mask R-CNN with feature pyramid and bounding box regression. Our approach is able to recognize the five most important wear types: flank wear, crater wear, fracture, built-up edge and plastic deformation. While other methods use image classification and classify only one wear type for each image, our model is able to detect multiple wear types. Over 35 models with different hyperparameter settings were trained on 5,000 labeled images to establish a reliable classifier. The results show up to 82.03% accuracy and benefit for overlapping wear types, which is crucial for using the model in production. Y1 - 2020 SN - 9783030583088 U6 - https://doi.org/10.1007/978-3-030-58309-5_18 SN - 0302-9743 SP - 223 EP - 234 PB - Springer International Publishing CY - Cham ER - TY - CHAP A1 - Rabenstein, L. A1 - Dietz, A. A1 - Kremser, A. A1 - Parspour, N. T1 - Semi-Analytical Calculation of a Laminated Transverse Flux Machine T2 - 2020 International Conference on Electrical Machines (ICEM) N2 - n this paper a semi-analytical calculation of a transverse flux machine is presented. First the design of the machine is explained, then the semi-analytical calculation, which is finally compared with a numerical 3D finite element analysis (FEA). The semi-analytical approach is based on a magnetic equivalent circuit, which is solved by nodal analysis and the Broyden-Method. The air gap of the machine is transformed into the magnetic equivalent circuit by conformal mapping using the Schwarz-Christoffel transformation. The comparison to numerical simulation shows that the approach gives good results and is sufficiently accurate for a rough design of the machine. KW - ransverse flux machine, passive rotor, magnetic equivalent circuit, conformal mapping, Schwarz- Christoffel transformation Y1 - 2020 U6 - https://doi.org/10.1109/icem49940.2020.9271065 SN - 2381-4802 SP - 721 EP - 727 PB - IEEE ER - TY - CHAP A1 - Gerstner, Michael A1 - Maerz, Martin A1 - Dietz, Armin T1 - Reconfigurable Transformer for Wide Input Voltage Range DC/DC Converters T2 - 2020 IEEE 9th International Power Electronics and Motion Control Conference (IPEMC2020-ECCE Asia) N2 - A transformer with variable primary windings for wide input voltage range DC/DC converters is presented. This transformer structure allows three states of the primary winding to be converted by only two individual windings. Based on the evaluations of a two-switch flyback converter, the potential of DC/DC converters with variable structures, the implementation of such a transformer and the advantages and disadvantages are shown and discussed. Real measurement results demonstrate the noticeable increase in efficiency and the reduction in component stress, having a positive influence on the operation of the converter and the component selection during the design process. KW - DC/DC converter ; efficiency ; tapped transformer ; wide input voltage range Y1 - 2020 U6 - https://doi.org/10.1109/ipemc-ecceasia48364.2020.9367869 PB - IEEE ER - TY - CHAP A1 - Saur, Gregor A1 - Kruglov, Roman A1 - Engelbrecht, Rainer T1 - Microsecond Optical Frequency Tuning of DFB Laser Diodes for Coherent Optical Frequency Domain Reflectometry N2 - Optical frequency tuning ranges up to 600 GHz or 4.8 nm have been achieved within microseconds and a standard telecom DFB laser diode operating at 1550 nm. The dynamic optical frequency tuning is induced by electrical current pulse injection and measured using an interferometric setup. Potentially, low-cost sensor systems based on optical coherence tomography (OCT) or coherent optical frequency domain reflectometry (c-OFDR) could be realized, achieving sub-mm two-point range resolution or even better single-point range precision within a few microseconds for a single measurement. KW - Tunable lasers KW - Semiconductor lasers KW - Wavelength shift KW - Fiber sensing Y1 - 2020 SN - 978-3-9819376-2-6 U6 - https://doi.org/10.5162/SMSI2020/C6.2 VL - 2020 SP - 189 EP - 190 PB - AMA Service GmbH CY - Wunstorf, Germany ER - TY - CHAP A1 - Schindler, Tobias A1 - Dietz, Armin T1 - Real-Time Inference of Neural Networks on FPGAs for Motor Control Applications T2 - 2020 10th International Electric Drives Production Conference (EDPC) N2 - Machine learning algorithms are increasingly used in industrial applications for a multitude of use-cases. However, using them in control tasks is a challenge due to real-time requirements and limited resources. In this paper, an implementation scheme for real-time inference of multilayer perceptron (MLP) neural networks on FPGAs is proposed. Design constraints for using MLPs in reinforcement learning agents for motor control applications are derived and accounted for in the implementation. Two MLP architectures are evaluated on an FPGA, and the timing and resource-usage data are reported. The real-time capability of the implementation for motor control applications is investigated for standard control frequencies. It is shown by experimental validation that real-time interference with an area-efficient implementation for motor control applications is achievable. Therefore, the proposed implementation scheme can be applied to deep reinforcement learning controllers with hard real-time requirements. Y1 - 2020 U6 - https://doi.org/10.1109/edpc51184.2020.9388185 SP - 1 EP - 6 PB - IEEE ER - TY - JOUR A1 - Chatzitakis, Paris A1 - Safarov, Javid A1 - Opferkuch, Frank A1 - Dawoud, Belal A1 - Hassel, Egon T1 - Vapor pressures and activity coefficients of 2,2,2-trifluoroethanol in binary mixtures with 1,3-dimethyl-2-imidazolidinone and 2-pyrrolidone JF - Journal of Molecular Liquids N2 - The vapor pressures of two binary mixtures containing 2-trifluoroethanol (TFE) + 1,3-dimethyl-2-imidazolidinone (DMI) and TFE + 2-pyrrolidone (PYR), were investigated at temperatures T = (274.15 to423.15) K using two different static method installations. Both combinations were modelled using an extended Clausius-Clapeyron equation with concentration dependent parameters and the NRTL equation with temperature dependent parameters. The best fit was obtained using the NRTL equation. KW - 2-Trifluoroethanol 1,3-Dimethyl-2-imidazolidinone 2-Pyrrolidone Vapor pressure NRTL Clausius-Clapeyron Y1 - 2020 U6 - https://doi.org/10.1016/j.molliq.2020.112828 SN - 0167-7322 VL - 305 PB - Elsevier BV ER - TY - JOUR A1 - Wendel, Sebastian A1 - Karamanakos, Petros A1 - Gebhardt, Philipp A1 - Dietz, Armin A1 - Kennel, Ralph T1 - Flux Linkage-Based Direct Model Predictive Current Control for Synchronous Machines JF - IEEE Transactions on Power Electronics N2 - This article presents a flux linkage-based direct model predictive current control approach that achieves favorable performance both during steady-state and transient operation. The former is achieved by computing the optimal time instants at which a new switch position is applied to the converter. To this end, the future current behavior is not computed based on the machine inductances or inductance look-up tables; instead, flux linkage maps are utilized to predict the trajectory of the magnetic flux linkage, and subsequently of the current. This is advantageous for electric drives with noticeable magnetic nonlinearity in terms of saturation and/or cross-coupling effects. Hence, by using flux linkage maps in the prediction process, the evolution of the stator current can be calculated more accurately, enabling the controller to make better switching decisions. Moreover, the discussed predictive controller exhibits excellent dynamic performance owing to its direct control nature, i.e., the control and modulation tasks are performed in one computational stage rendering a dedicated modulation stage redundant. Three different drive systems based on permanent magnet synchronous motors are examined to demonstrate the effectiveness of the presented control approach. Y1 - 2021 U6 - https://doi.org/10.1109/tpel.2021.3083657 SN - 0885-8993 VL - 36 IS - 12 SP - 14237 EP - 14256 PB - Institute of Electrical and Electronics Engineers (IEEE) ER - TY - CHAP A1 - Hümmer, Michael A1 - Schirmer, Julian A1 - Klauss, Matthias A1 - Reichenberger, Marcus T1 - Characterization of Crimp Interconnections for Hybrid Integration of Screen-Printed Electronics T2 - 2021 44th International Spring Seminar on Electronics Technology (ISSE) N2 - In this work, electrical contacts between piercing-crimp terminals and screen-printed silver structures on three different polymeric films are characterized electrically and mechanically before and after accelerated thermal aging tests. Temperature cycling and constant thermal load tests were performed as like as ampacity and resistance measurements and tensile tests. The tensile tests show that the mechanical strength of the crimp connection depends on substrate material, but is independent of the aging state. For all joints, breaking forces of more than 100 N were achieved. Furthermore, some of tested connections can be loaded with more than 2.5 A in unaged state till they heat up by 25 K. Besides that, accelerated thermal aging generally leads to a reduction in electrical resistance in our experiments. Y1 - 2021 U6 - https://doi.org/10.1109/isse51996.2021.9467558 PB - IEEE ER - TY - JOUR A1 - Schirmer, Julian A1 - Hümmer, Michael A1 - Klauß, Matthias A1 - Neermann, Simone A1 - Reichenberger, Marcus A1 - Franke, Jörg T1 - Evaluation of detatchable board-to-board interconnects on screen printed electronic structures JF - Flexible and Printed Electronics N2 - Hybrid printed electronics (HPE) combines advantages of conventional electronics manufacturing technologies such as surface mount technology with those of printed electronics in order to realize more complex electronic systems. To realize the final product, such HPE subassemblies have to be connected to higher-level assemblies. So far interconnection techniques for the so-called level 3 interconnection between printed subsystems and standard electronics have not yet been considered adequately in scientific research. In this paper, alternative detachable level 3 interconnection technologies, i.e. spring loaded contact pins, zero insertion force (ZIF) as well as Non-ZIF connectors are investigated systematically regarding their electrical behaviour against the background of printed electronics. Screen-printed silver filled polymer thick film paste is used to realize printed conductor patterns on flexible polymer substrates, which are connected later on with the alternatives mentioned above. Transition resistance is measured using the four wire method as produced, after repeated mating cycles as well as after accelerated aging tests. The various electrical contacts are subjected to thermal stress in temperature cycling testing and during aging at a constant high temperature. As a result it can be stated, that the sping-loaded contact pins used in this investigation show superior behavior compared with the selected connectors in terms of resistance increase after mating cycles. Concerning long-term behavior after thermal cyling and high temperature storage, all investigated alternaives reveal convincing results. Y1 - 2021 U6 - https://doi.org/10.1088/2058-8585/ac1fd5 SN - 2058-8585 VL - 6 IS - 3 PB - IOP Publishing ER - TY - CHAP A1 - Schirmer, Julian A1 - Reichenberger, Marcus A1 - Neermann, Simone A1 - Franke, Jorg T1 - Conformable Electronics: Thermoforming and Injection Molding of Electronic Components N2 - In this paper the stress on electronic components for Conformable Electronic applications is evaluated. During High-Pressure-Forming (HPF) and subsequent overmolding (OM) these components have to withstand high amounts of stress. Globtops are used to protect 0402 as well as 0603-sized components mounted on different polymer substrates. The components are placed in different areas of deformation (for HPF) and melt velocities (for OM). The components are afterwards examined by means of electrical resistance measurements and shear force measurements as well as micro-sections. For conductive adhesive, the globtop material positively influenced the resistance change after deformation, soldered assemblies showcased good formability up to 20 %. The shear force drop caused by higher deformations could be mitigated using globtop materials. Soldered components were able to withstand OM when globtops were used. Here, smaller components seem to take less damage from the impacting melt. Components should be placed in areas where the melt has cooled down to prevent damages. Y1 - 2021 U6 - https://doi.org/10.1109/isse51996.2021.9467588 PB - IEEE ER - TY - CHAP A1 - Schirmer, Julian A1 - Reichenberger, Marcus A1 - Wimmer, Annette A1 - Reichel, Herbert A1 - Neermann, Simone A1 - Franke, Jorg T1 - Evaluation of Mechanical Stress on Electronic Assemblies During Thermoforming and Injection Molding for Conformable Electronics N2 - The integration of SMT components is necessary to produce more complex assemblies within the framework of conformable electronics. During High-Pressure-Forming (HPF) and subsequent overmolding electronic components must withstand high amounts of stress. In this study 0402- as well as 0603-sized chip resistors were mounted on different common polymer substrates using conductive adhesive paste followed by electrical and mechanical evaluation. Prior to HPF electronic components were positioned in areas of different local deformation. After HPF the specimen were characterized by shear force testing and electrical resistance measurements. In a similar manner, electronic components were tested to assess the mechanical behavior during injection molding. To examine different melt induced stress scenarios, electronic components were arranged parallel as well as perpendicular to the flow direction of the melt at different positions. Additionally, three different injection speeds were evaluated to assess the influence on the electrical conductivity and functionality of the assemblies. It was found that meandering of conductors is necessary for higher deformations. El. components (without additional nonconductive adhesives) can be placed in areas of up to 15% deformation, smaller package sizes seem to be advantageous for HPF. Regarding overmoulding, it was found that larger components (larger bonding area) is beneficial. Also, placement near the injection point, as well as low injection speeds should be avoided. Overall, el. components should be protected (using globtops / underfills etc.) to withstand consecutive HPF and overmoulding. Y1 - 2021 U6 - https://doi.org/10.1109/mid50463.2021.9361624 PB - IEEE ER - TY - CHAP A1 - Roudenko, Jewgeni A1 - Neermann, Simone A1 - Schirmer, Julian A1 - Reichenberger, Marcus A1 - Franke, Jorg T1 - Sintering of digitally printed silver nanoparticle inks on flexible and rigid substrates by NIR- and UVradiation N2 - In the research project AVerdi the influence of photonic sintering methods on the resulting electrical conductivity, sintering duration and adhesion of digitally printed silver nanoparticle inks was investigated and compared to convective sintering. Conductor paths with film thicknesses below 1 μm were applied on flexible polymer substrates via inkjet printing. Aerosoljet printing was used to generate thicker lines up to 11 μm on injection molded substrates. Photonic sintering was carried out with near infrared emitters or ultraviolet light emitting diodes. For inkjet printed structures on polyimide a conductivity up to 24 % relative to bulk silver was achieved after a sintering duration of 2 s and 5 s for the near infrared and the ultraviolet light source, respectively. Oven sintered samples showed an electrical conductivity of 14 % after 1 h at 200° C. On polyethylene terephthalate a conductivity around 7 % was achieved after irradiation with near infrared light for 1 s, whereas convectively sintered samples showed a conductivity around 4 %. All material combinations sintered by the different methods showed good adhesion. The overall results of long-term behavior after thermal-cycling, regarding electrical conductivity and adhesion, show that the photonically sintered structures achieve similar results compared to the reference. The photonically sintered structures generated with the aerosoljet on polyamide 6 achieved conductivity values up to 19 %, which were comparable to the furnace sintered reference samples. On liquid crystal polymer substrates conductivity values reached up to 35 % after sintering with ultraviolet light emitting diodes for 60 s. Oven sintered samples showed a conductivity around 25 % after 1 h at 150° C. The adhesion of the silver nanoparticle ink on liquid crystal polymer and polyamide 6 substrates is better than with the reference samples. The reliability tests show fewer failures with alternative sintered samples. In this study only the results for inkjet printed structures are presented. Y1 - 2021 U6 - https://doi.org/10.1109/mid50463.2021.9361627 PB - IEEE ER - TY - CHAP A1 - Bergner, Christian A1 - Akan, Ferhat A1 - Schmidt-Vollus, Ronald A1 - Heß, Peter A1 - Deuerlein, Christian T1 - Portable Safety System using Radar for Flexible Human-Robot-Collaboration in a Real Semi-automated Production Line T2 - Proceedings of the 2nd International Conference on Robotics, Computer Vision and Intelligent Systems ROBOVIS - Volume 1 N2 - The implementation of a reliable vision system for a human-robot environment is a key issue for the collaborative production industry. The core challenge of human-robot collaboration is to ensure safety. Furthermore, a flexible safety system is required for frequently changing applications and work areas. This paper focuses on the development and application of a workspace monitoring system for safeguarding using radar sensors. The human-robot collaboration cell is designed to enable a flexible integration regardless of the work location. This results in higher productivity. Since no separating protective devices are provided for the cell, safety-oriented monitoring and control by suitable safety sensors is required. The methods to minimize the size of the necessary safety distance will be presented. The experimental validation shows that this safety system with radar sensors performs a reliable workspace monitoring system. The high robustness, reactivity and flexibility of the safet y concept makes this system usable for collaborative tasks in a real industrial environment. KW - Human-Robot-Collaboration, Safety System, Radar, Flexibility, Portability, Standard-CE. Y1 - 2021 SN - 978-989-758-537-1 U6 - https://doi.org/10.5220/0010645800003061 SP - 67 EP - 76 PB - SCITEPRESS - Science and Technology Publications ER - TY - JOUR A1 - Kofer, Daniel A1 - Bergner, Christian A1 - Deuerlein, Christian A1 - Schmidt-Vollus, Ronald A1 - Heß, Peter T1 - Human–robot-collaboration: Innovative processes, from research to series standard JF - Procedia CIRP N2 - Sensitive robots are an innovative technology of tomorrow ´s production. The Human–Robot-Collaboration (HRC) with its variable combination of unique skills represents a future-oriented form of work. Yet, there is a lack of experience in process realization, safety requirements are often not given and economic efficiency is still missing. There are a lot of innovative process solutions in research but industrial conditions are less considered. In this work, the approaches for the realization of standardizable HRCs for assembly operations in the automotive sector will be outlined. The aim is to present simple ways from the idea to series production by considering permitted limits. Based on an industrial application, innovative collaborations are realized with only few hardware and software components. In this context, standard compliant safety is ensured through internal system features and adjusted component designs. Additionally, an approach for HRC safety through real-time monitoring of the endeffector area is presented. As an outlook there is a guideline for HRC realization. KW - Human–robot-collaboration Hybrid assembly Safe operation Ergonomics Y1 - 2021 U6 - https://doi.org/10.1016/j.procir.2020.09.185 SN - 2212-8271 VL - 97 SP - 98 EP - 103 PB - Elsevier BV ER - TY - CHAP A1 - Dengler, Simon Andreas A1 - Vinogradov, Juri A1 - Ziemann, Olaf A1 - Engelbrecht, Rainer A1 - Schmauß, Bernhard T1 - Low Cost POF OTDR Reaches 200 m Sensing Distance KW - Optische Polymerfaser Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:92-opus4-26577 VL - 2021 SP - 13 PB - The International Committee on Polymer Optical Fibers, ICPOF CY - Jinhua City ER - TY - CHAP A1 - Dengler, S. A1 - Schmidt, N. A1 - Luber, M. A1 - Fischer, J. A1 - Ziemann, Olaf A1 - Engelbrecht, Rainer A1 - Hangen, H. T1 - B8.3 Influence of Temperature on Distributed Strain Sensing with OTDR in Polymer Optical Fibers T2 - SMSI 2021 - Sensors and Instrumentation N2 - Strain in ground and earthworks can be measured by polymer optical fibers (POF) applied to geotextiles. We measure the increase of backscatter (IOB) in the fiber under strain using optical time domain reflectometry (OTDR). The effect of temperature on this measurement principle is investigated. The local backscatter changes by 0.003 dB/K for common ambient temperature. In addition it is shown, that temperature depended viscoelastic properties of the polymer does affect IOB. KW - optical time domain reflectometry, structural health monitoring, strain sensing, geotextiles, polymer optical fib Y1 - 2021 SN - 978-3-9819376-4-0 U6 - https://doi.org/10.5162/smsi2021/b8.3 SP - 155 EP - 156 PB - AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf, Germany ER - TY - JOUR A1 - Dengler, Simon A. A1 - Engelbrecht, Rainer A1 - Schmauss, Bernhard T1 - Absolute spectral backscatter measurements of large-core multimode PMMA polymer optical fibers JF - Optics Express N2 - To our knowledge, we are the first to measure the absolute value of the backscattering coefficient of a standard 1 mm core-diameter, multimode (MM) step-index (SI) polymethylmethacrylate (PMMA) polymer optical fiber (POF) for the spectral range of 450 nm to 700 nm. Our optical time domain reflectometer (OTDR) setup consists of a femtosecond supercontinuum laser with an acousto-optical filter as a tunable light source with short pulses and a time-correlated single-photon counting system as a receiver with a high dynamic range. The backscattering coefficient is calculated from the ratio between the energy within the fiber end reflex and the distributed backscattering level. We also measured the spectral attenuation with our OTDR setup and compared it with a standardized measurement method. At the attenuation minima within the measured spectral range the backscattering level of a 1 ns pulse is about −46 dB at 520 nm, −48 dB at 570 nm, and −51 dB at 650 nm. We were also able to show by the observed wavelength dependence that Rayleigh scattering causes a majority of the scattering. Y1 - 2021 U6 - https://doi.org/10.1364/oe.437903 SN - 1094-4087 VL - 29 IS - 21 SP - 34629 EP - 34640 PB - Optica Publishing Group ER - TY - CHAP A1 - Dietz, Armin A1 - di Tommaso, A. O. A1 - Miceli, R. A1 - Nevoloso, C. A1 - Schettino, G. T1 - Enhanced Modelling for Extended Performance Analysis of Interior Permanent Magnet Synchronous Machine Drive fed with Cascaded H-Bridges Multilevel Inverter T2 - 2021 Sixteenth International Conference on Ecological Vehicles and Renewable Energies (EVER) N2 - This paper presents a comparative simulation analysis of an Interior Permanent Magnet Synchronous Machine (IPMSM) performance once fed by a traditional three-phase two-level inverter and then using a three-phase five-level Cascaded H-Bridges Multilevel Inverter (CHBMI). For this purpose, an enhanced mathematical model of the IPMSM, that take into account simultaneously saturation, cross-coupling, spatial harmonics and iron loss effects, has been employed. Furthermore, two different PWM modulation strategies have been considered. The study was conducted for several working conditions, evaluating the impact of CHBMI adoption on the IPMSM performance in terms of improved efficiency and torque ripple reduction. Y1 - 2021 U6 - https://doi.org/10.1109/ever52347.2021.9456635 PB - IEEE ER - TY - CHAP A1 - Dietz, Michael A1 - Meissner, Barbara A1 - Goppelt, Florian A1 - Schmidt-Vollus, Ronald T1 - On the Development of Virtual Labs Using Digital Twins and a Proposal for Didactic Optimization Using Design-Based Research T2 - 2021 Fifth World Conference on Smart Trends in Systems Security and Sustainability (WorldS4) N2 - In laboratory practicals (labs), students actively investigate technical and scientific phenomena and thus experience autonomy, competence, and social embedding, factors that promote motivation. However, labs mostly rely on highly structured and instructive concepts and often require costly equipment. Therefore, the research question in this paper is: How can learner-centered teaching methods and learning formats be improved by rethinking the digitization of lab practicals? Y1 - 2021 U6 - https://doi.org/10.1109/WorldS451998.2021.9514044 PB - IEEE ER - TY - CHAP A1 - Gerstner, Michael A1 - Maerz, Martin A1 - Dietz, Armin T1 - Review-based Selection Recommendation for Galvanically Isolated DC/DC Converters Designed For a Wide Input Voltage Range T2 - 2021 IEEE 19th International Power Electronics and Motion Control Conference (PEMC) N2 - Depending on the application range, there are various recommendations in the literature which converter topology should be used. These are mostly based on experience or more or less deeper considerations. For DC/DC converters, which are operated over a wide input voltage range, such recommendations rarely exist. Therefore, this contribution shows the evolution of two input voltage dependent selection matrices, which should facilitate the selection of future topologies based on known publications and basic considerations. The focus here lies on converters for λ = V i_max /V i_min ≥ 3 with galvanic isolation. First, the data set is introduced, where a distinction is made between flyback converters, forward converters and other 1stage or 2stage converters before the evolution of the novel input voltage dependent matrices is carried out. These two matrices support the selection of a suitable topology and whether the energy transfer should be done by one or two stages. Y1 - 2021 U6 - https://doi.org/10.1109/pemc48073.2021.9432537 SP - 167 EP - 172 PB - IEEE ER - TY - CHAP A1 - Liegmann, Eyke A1 - Schindler, Tobias A1 - Karamanakos, Petros A1 - Dietz, Armin A1 - Kennel, Ralph T1 - UltraZohm — An Open-Source Rapid Control Prototyping Platform for Power Electronic Systems T2 - 2021 International Aegean Conference on Electrical Machines and Power Electronics (ACEMP) & 2021 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM) N2 - This paper presents two rapid control prototyping (RCP) use cases facilitated by the open-source platform UltraZohm. The openly available UltraZohm development frame- work eases the transition from simulation to the test bench. The framework offers the integration of automatic code generation for field-programmable gate arrays (FPGAs), either by using Simulink models based on the HDL Coder, or by synthesizing C++ code into VHDL via the Vivado high-level synthesis tool. The first use case focuses on the implementation details of an on-chip controller-in-the-loop setup, where a permanent magnetsynchronous machine is emulated in the FPGA with a sampling frequency of 2 MHz. The second use case presents an efficient real-time implemen-tation of the sphere decoding algorithm employed to solve the long-horizon finite control set model predictive control problem for a three-level neutral point clamped inverter driving an induction machine. Experimental results based on a small-scale prototype confirm that the algorithm can be executed in real time on the FPGA, with an execution time of a few tens of microseconds. Both use cases highlight the benefits of using a high-performance RCP platform for research in power electronics and their control. Y1 - 2021 U6 - https://doi.org/10.1109/optim-acemp50812.2021.9590016 SN - 1842-0133 PB - IEEE ER - TY - GEN A1 - Harms, Patrick T1 - Testing at the Edge of Reality - Virtual Prototyping and Opportunities for Test Automation Y1 - 2021 ER - TY - CHAP A1 - Engelbrecht, Rainer A1 - Saur, G. A1 - Kruglov, R. T1 - B8.4 12 nm Spectral Shift with a VCSEL in the Near Infrared in a 10 µs Time Interval T2 - SMSI 2021 - Sensors and Instrumentation N2 - An optical wavelength tuning range up to 12 nm has been achieved within 10 μs, using VCSELs operating in the near infrared. The range has been measured with an interferometric setup and an optical spectrum analyzer respectively. Potentially, low-cost sensor systems based on tunable diode laser absorption spectroscopy or coherent optical frequency domain reflectometry could be realized, achieving sub-mm two-point range resolution or even better single-point range precision within a few microseconds for a single measurement. Y1 - 2021 SN - 978-3-9819376-4-0 U6 - https://doi.org/10.5162/smsi2021/b8.4 SP - 157 EP - 158 PB - AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf, Germany ER - TY - CHAP A1 - Steinbrink, Marco A1 - Koch, Philipp A1 - Jung, Bernhard A1 - May, Stefan T1 - Rapidly-Exploring Random Graph Next-Best View Exploration for Ground Vehicles T2 - 2021 European Conference on Mobile Robots (ECMR) N2 - In this paper, a novel approach is introduced which utilizes a Rapidly-exploring Random Graph to improve sampling-based autonomous exploration of unknown environments with unmanned ground vehicles compared to the current state of the art. Its intended usage is in rescue scenarios in large indoor and underground environments with limited teleoperation ability. Local and global sampling are used to improve the exploration efficiency for large environments. Nodes are selected as the next exploration goal based on a gain-cost ratio derived from the assumed 3D map coverage at the particular node and the distance to it. The proposed approach features a continuously-built graph with a decoupled calculation of node gains using a computationally efficient ray tracing method. The Next-Best View is evaluated while the robot is pursuing a goal, which eliminates the need to wait for gain calculation after reaching the previous goal and significantly speeds up the exploration. Furthermore, a grid map is used to determine the traversability between the nodes in the graph while also providing a global plan for navigating towards selected goals. Simulations compare the proposed approach to state-of-the-art exploration algorithms and demonstrate its superior performance. Y1 - 2021 U6 - https://doi.org/10.1109/ecmr50962.2021.9568785 PB - IEEE ER -