Towards brand-independent architectures, components and systems for next generation electrified vehicles optimised for the infrastructure. - In: SAE international journal of advances and current practices in mobility, ISSN 2641-9645, Bd. 4 (2022), 5, S. 1906-1922
E-mobility is a game changer for the automotive domain. It promises significant reduction in terms of complexity and in terms of local emissions. With falling prices and recent technological advances, the second generation of electric vehicles (EVs) that is now in production makes electromobility an affordable and viable option for more and more transport mission (people, freight). Still, major challenges for large scale deployment remain. They include higher maturity with respect to performance (e.g., range, interaction with the grid), development efficiency (e.g., time-to-market), or production costs. Additionally, an important market transformation currently occurs with the co-development of automated driving functions, connectivity, mobility-as-a-service. New opportunities arise to customize road transportation systems toward application-driven, user-centric smart mobility solutions. The target of this paper is to provide a consolidated view of several related European research programs having the common goal to develop innovative, brand-independent architectures, components and systems for next generation electrified vehicles optimised for the infrastructure under the umbrella of the E-VOLVE cluster. This regroups the projects ACHILES, SYS2WHEEL, EVC1000 introducing innovative in-wheel motors for different vehicle segments, CEVOLVER introducing optimized concepts for energy and thermal management, and Multi-Moby focusing on the development of safe, efficient and affordable urban electric vehicles.
https://doi.org/10.4271/2022-01-0918
Electric vehicle corner architecture: driving comfort evaluation using objective metrics. - In: SAE technical papers, ISSN 2688-3627, (2022), 2022-01-0921, S. 1-7
The presented paper is dedicated to the driving comfort evaluation in the case of the electric vehicle architecture with four independent wheel corners equipped with in-wheel motors (IWMs). The analysis of recent design trends for electrified road vehicles indicates that a higher degree of integration between powertrain and chassis and the shift towards a corner-based architecture promises improved energy efficiency and safety performances. However, an in-wheel-mounted electric motor noticeable increases unsprung vehicle mass, leading to some undesirable impact on chassis loads and driving comfort. As a countermeasure, a possible solution lies in integrated active corner systems, which are not limited by traditional active suspension, steer-by-wire and brake-by-wire actuators. However, it can also include actuators influencing the wheel positioning through the active camber and toe angle control. Such a corner configuration is discussed in the paper as applied to a sport utility vehicle (SUV). A new chassis design was developed and tested for this reference vehicle using multi-body dynamics simulation. The integrated operation of the active suspension and the wheel positioning control has been analyzed in this study with different driving scenarios and objective metrics for driving comfort evaluation. Additionally, handling and stability tests have also been performed to confirm that new systems do not deteriorate driving safety. The obtained results contribute to a comprehensive assessment of IWM-based architecture, formulated from a driving comfort perspective that is helpful for further designs of electric vehicle corners.
https://doi.org/10.4271/2022-01-0921
Active control of Camber and Toe angles to improve vehicle ride comfort. - In: SAE technical papers, ISSN 2688-3627, (2022), 2022-01-0920, S. 1-14
This paper is part of the European OWHEEL project. It proposes a method to improve the comfort of a vehicle by adaptively controlling the Camber and Toe angles of a rear suspension. The purpose is achieved through two actuators for each wheel, one that allows to change the Camber angle and the other the Toe angle. The control action is dynamically determined based on the error between the reference angle and the actual angles. The reference angles are not fixed over time but dynamically vary during the maneuver. The references vary with the aim of maintaining a Camber angle close to zero and a Toe angle that follows the trajectory of the vehicle during the curve. This improves the contact of the tire with the road. This solution allows the control system to be used flexibly for the different types of maneuvers that the vehicle could perform. An experimentally validated sports vehicle has been used to carry out the simulations. The original rear suspension is a Trailing-arm suspension. It has been modified via Adams Car. The simulations have been carried out using the same software in cosimulation with Simulink. The suspension has been tested through a Parallel Wheel Travel analysis and an Opposite Wheel Travel analysis. The maneuvers carried out have been two variations of Constant Radius Cornering, two variations of Fish-Hook and two variations of Swept-Sine Steer. A decrease in the vertical acceleration of the center of gravity has been achieved by controlling the Camber angle for maneuvers where a trajectory or rotation of the steering is imposed. The Toe angle control has allowed a decrease in vertical acceleration when a trajectory is imposed. In particular, the decrease of the Root Mean Square and the maximum absolute value have been obtained. These results demonstrate an improvement in Ride Comfort.
https://doi.org/10.4271/2022-01-0920
Enhancement of vision-based 3D reconstruction systems using radar for smart farming. - In: 2022 IEEE International Workshop on Metrology for Agriculture and Forestry, (2022), S. 155-159
Digital field recordings are central to most precision agriculture systems since they can replicate the physical environment and thus monitor the state of an entire field or individual plants. Using different sensors, such as cameras and radar, data can be collected from various domains. Through the combination of radio wave propagation and visible light phenomena, it is possible to enhance, e.g., the optical condition of a fruit with internal parameters such as the water content. This paper proposes a method to correct sensor errors to perform data fusion. As an example, we observe a watermelon with camera and radar sensors and present a system architecture for the visualization of both sensors. For this purpose, we constructed a handheld platform on which both sensors are mounted. In our report, the radar is analyzed in terms of systematic and stochastic errors to formulate an angle-dependent mapping function for error correction. It is successfully shown that camera and radar data are correctly assigned with a watermelon used as a target object, demonstrated by a 3D reconstruction. The proposed system shows promising results for sensor overlay, but radar data remain challenging to interpret.
https://doi.org/10.1109/MetroAgriFor55389.2022.9964699
A study for laser additive manufacturing quality and material classification using machine learning. - In: IEEE SENSORS 2022, (2022), insges. 4 S.
This paper demonstrates the use of acoustic emissions (AEs) to monitor the quality, and material used, for the laser additive manufacturing (LAM) process with steel and copper wire. Layers of deposited material (steel or copper) were created using LAM. The quality of these layers was either good or unstable. The AEs were recorded using three sensors, one microphone, and two structure-borne sound probes. The recorded signals were processed and transformed using the fast Fourier method. Then models were trained with the processed data and evaluated using a fivefold cross-validation. Results show that it is possible to accurately classify the materials used during LAM (up to a balanced accuracy [BAcc] score of 0.99). Also, the process quality could be classified with a BAcc score of up to 0.81. Overall, the results are promising, but further research and data collection are necessary for a proper validation of our results.
https://doi.org/10.1109/SENSORS52175.2022.9967311
Bewältigung der Lehre unter Corona-Bedingungen an einer der kleineren Universitäten. - In: Lessons learned, ISSN 2749-1307, Bd. 2 (2022), 1, 35, insges. 10 S.
Die Technische Universität Ilmenau versucht auch unter „Corona-Zwängen“ durch Kontakteinschränkungen in Kombination mit begrenzten Lehrkapazitäten Seminare, Übungen und Praktika angemessen durchzuführen und die Lehre nicht zu vorlesungslastig werden zu lassen. Die Seminar- und Praktikumsräume gaben jedoch auch unter intensiver zeitlicher Raumbewirtschaftung von 7 Uhr bis 21 Uhr „zentral“ wie durch die Fachgebiete bei Einhaltung der Hygienevorschriften keine ausreichenden Kapazitäten zur Durchführung in Präsenz her. Der Beitrag berichtet daher über von uns getestete Möglichkeiten zur Umsetzung der etablierten Lehrformate in Onlineformate. Zusätzlich werden Lösungen zur sicheren Realisation von Präsenzprüfungen unter Pandemie-Bedingungen dargestellt. Daher war ab April 2020 neben der relativ einfach umzusetzenden Online-Durchführung der Vorlesungen für die Seminare und insbesondere die Praktika viel Eigeninitiative und Einfallsreichtum erforderlich, um den eigenen Qualitätsanforderungen der Lehrenden genüge leisten zu können. Im Vortrag wird über ausgewählte Beispiele der so entstandenen Lösungen berichtet, wie sie in der Fakultät für Maschinenbau der Technischen Universität Ilmenau realisiert wurden. Unsere Fakultät weist ein breites Spektrum von „klassischen“ Fächern bis zu Lichttechnik, Technischer Optik und Biomechatronik auf, so dass schon bei dieser Stichprobe aus nur einem Fachgebiet einer der fünf Fakultäten die dem Wissenschaftler gemeine übergreifende Bewertung kaum zu bieten ist. Selbstverständlich wird nicht nur über Lösungen berichtet, sondern die ungelösten Probleme werden gleichrangig angesprochen.
https://doi.org/10.25369/ll.v2i1.35
Lateral 2D TMDC memristors - experiment and modeling. - In: Proceedings of 2022 IEEE 16th International Conference on Solid-State & Integrated Circuit Technology (ICSICT), (2022), insges. 3 S.
Memristors are promising devices for future neuromorphic computing applications. Typically, memristors consist of a vertical metal-insulator-metal stack. Recently memristors using layered transition metal dichalcogenides (TMDCs) for the active device region have attracted much attention. In the present paper, we report on the fabrication of lateral WSe2 and MoS2 memristors and present measured current-voltage (I-V) characteristics of these devices. Moreover, a model for calculating the I-V characteristics of lateral TMDC memristors is presented. We show that the model can correctly reproduce the experimental I-V characteristics of our devices.
https://doi.org/10.1109/ICSICT55466.2022.9963350
Microwave transistors - the backbone of 5G and beyond communication systems. - In: Proceedings of 2022 IEEE 16th International Conference on Solid-State & Integrated Circuit Technology (ICSICT), (2022), insges. 4 S.
The era of global mobile connectivity began more than 40 years ago with the introduction of the first generation (1G) of mobile communication systems in 1979. With 1G it became possible to exchange voice messages between interlocutors being in the same building or thousands of miles apart without the need for a fixed line. Meanwhile 5G systems are in operation, much more than just voice messages are exchanged, and the mobile data traffic is growing extremely quickly. Therefore, higher frequency bands have to be used for mobile data transmission. In the present paper we discuss the status of microwave transistors, which represent the backbone of the hardware of mobile communication systems. Furthermore, we deal with the questions if microwave transistors operating properly in the upper frequency bands allocated for 5G communications are at hand and whether transistors for the 100 GHz … 3 THz range envisaged for beyond 5G systems are feasible.
https://doi.org/10.1109/ICSICT55466.2022.9963340
Comparison of angle-dependent scattering of convoluted and straight microwave absorbers. - In: AMTA 2022 proceedings, (2022), insges. 6 S.
The increasing complexity and sensitivity of wireless communication systems enforce the requirements for test environments such as anechoic chambers. The minimum achievable level of interference between desired signal and scattered copies is essentially determined by the reflectivity of the installed absorbers, emphasizing the importance of thoroughly characterizing the scattering behavior of absorbers. In this paper, the scattering off absorbers with different geometric shapes, namely convoluted, pyramidal, wedge, and flat, is investigated using a numerical unit-cell model. To verify the simulation model, the angle-dependent reflectivity of the convoluted absorbers was measured at different angles-of-incidence between 2GHz and 18GHz. The numerical results agree well with the measured reflectivity at representative angles-of-incidence, validating the numerical model and revealing the expected increase in reflectivity for increasing beam tilts. Further, it becomes apparent that the performance of all shapes decreases similarly at oblique incidence. These results contribute to build a comprehensive database on the angle- and frequency-dependent reflectivity of absorbers, in order to develop a consistent data body, e.g., for modelling anechoic environments.
https://doi.org/10.23919/AMTA55213.2022.9955000
Emulation of LTE link scenarios reproducibly derived from field-operational tests. - In: AMTA 2022 proceedings, (2022), insges. 6 S.
Virtual drive tests using the over-the-air/vehicle-in-the-loop method are becoming an essential part of testing vehicular radio systems. Different approaches ask which link scenarios and channel environments are relevant and should be tested. This paper deals with the systematic evaluation of field-operational tests and the implementation of virtual drive tests of LTE communication links focussing on the performance of the radio link close to the edges of the radio cells, which are identified as a relevant testing scenario. For this purpose, three test drives were performed on each of two test tracks. Close to cell edges the available data throughput is as much as a factor of 10 lower than the maximum available data throughput along the test track and reduced approximately by half compared to the average data throughput in the cell center. Instead of trying to recreate the entire test drive with high accuracy, this approach focusses on recreating the critical parts of a test drive in the laboratory, as these are the most likely to cause radio link failure in real operation. Therefore, the physical parameters in terms of serving signal strength and level of interfering signals were transferred to a wired virtual test, and the data rate was examined again. Despite some systematic differences between real drive test and virtual drive test, which could be clearly identified, it was possible to reproduce the behavior at the cell edge very precisely with deviations smaller than 5 %.
https://doi.org/10.23919/AMTA55213.2022.9954989