Abstract:Since the evolution of the electric and hybrid vehicle, the analysis of batteries' characteristics and influence on driving range has become essential. This fact advocates the necessity of accurate simulation modeling for batteries. Different models for the Li-ion battery cell are reviewed in this paper and a group of the highly dynamic models is selected for comparison. A new open circuit voltage (OCV) model is proposed. The new model can simulate the OCV curves of lithium iron magnesium phosphate (LiFeMgPO 4 ) battery type at different temperatures. It also considers both charging and discharging cases. The most remarkable features from different models, in addition to the proposed OCV model, are integrated in a single hybrid electrical model. A lumped thermal model is implemented to simulate the temperature development in the battery cell. The synthesized electro-thermal battery cell model is extended to model a battery pack of an actual electric vehicle. Experimental tests on the battery, as well as drive tests on the vehicle are performed. The proposed model demonstrates a higher modeling accuracy, for the battery pack voltage, than the constituent models under extreme maneuver drive tests.

Automotive radar sensors play a vital role in the current development of autonomous driving. Their ability to detect objects even under adverse conditions makes them indispensable for environment-sensing tasks in autonomous vehicles. As their functional operation must be validated in-place, a fully integrated test system is required. Radar Target Simulators (RTS) are capable of executing end-of-line, over-the-air validation tests by looping back a received and afterward modified radar signal and have been incorporated into existing Vehicle-in-the-Loop (ViL) test beds before. However, the currently available ViL test beds and the RTS systems that they consist of lack the ability to generate authentic radar echoes with respect to their complexity. The paper at hand reviews the current development stage of the research as well as commercial ViL and RTS systems. Furthermore, the concept and implementation of a new test setup for the rapid prototyping and validation of ADAS functions is presented. This represents the first-ever integrated radar validation test system to comprise multiple angle-resolved radar target channels, each capable of generating multiple radar echoes. A measurement campaign that supports this claim has been conducted.

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The internal drum test bench of the Universität Karlsruhe (TH) allows tire performance measurements under controllable conditions. In cooperation with Continental AG a research project was initiated to focus on traction on ice and snow surfaces. The test chamber was upgraded with a cooling system, surface conditioners and a snow production system. As a major result of these experiments, a strong correlation of thermal conditions and transmittable forces has been discovered. Furthermore, a high-speed infrared camera was used to monitor the temperature increase of the tire surfaces under traction. This paper presents the developed theoretical model, which describes the time dependent temperature increase in the contact zone. Based on this model, a formula to determine the thermal limiting curve of force transmission on ice and snow was derived. The computed curves were verified through comparison with experimental data.

Zusammenfassung Modellbasierte Verfahren zur Fahrdynamikregelung beruhen auf einer Beschreibung des Reifen-Fahrbahn-Kraftschlusspotenzials. Dieser Beitrag beschreibt eine neue Methode zur schlupfbasierten Fahrbahnreibwertschätzung unter besonderer Berücksichtigung der on-line Anwendung. Hierzu wird eine optimale lineare Parametrierung des Burckhardt-Reifenmodells untersucht. Gegenüber bisherigen Arbeiten erzielt das vorgeschlagene Modell eine verbesserte Approximation. Des Weiteren werden Parameterschätzverfahren für das Modell diskutiert und in einer Gesamtfahrzeugsimulation evaluiert.