Reimund Limbacher

Negative Behavioral Adaptation to Lane-Keeping Assistance Systems

In addition to the improvement of driving comfort, modern advanced driver assistance systems also aim to substantially increase traffic safety. Meanwhile, initial optimism with respect to potential safety gains has given way to a more critical view. There is, for example, a danger that continued use is associated with drivers systematically adapting their behavior to the new systems in a negative manner. According to theoretical considerations, excessive trust in such systems may lead to the development of a tendency for the driver to delegate safety-relevant aspects of the driving task to the system, which, in cases where system limits are reached, can result in the driver and other road users being endangered. The present study examined this phenomenon in the context of lateral control assistance. In a field experiment, it was specifically investigated whether drivers who had become familiar with a heading control system developed excessive trust in the system and misjudged its limits. This question was addressed in a driving trial in which, unbeknown to the driver, the heading control system was repeatedly deactivated and the drivers behavior and lane control were observed. Analysis of subjective and objective data clearly demonstrated that drivers did not develop excessive trust in the system and accordingly regulated lateral control to a sufficient degree even after prolonged exposure to the system. Negative behavioral adaptation to the heading control system was thus not observed.

Robust estimation of vehicle longitudinal dynamics parameters

Vehicle longitudinal control can be improved by knowledge of vehicle parameters. A robust estimation algorithm is presented to estimate unknown or uncertain vehicle parameters. These parameters are mass, rolling coefficient, air drag coefficient and brake disc friction coefficient. The proposed estimator considers non-Gaussian measurement errors, insufficient excitation and a prior knowledge of parameter bounds. The robust estimator shows good performance on real-world data with difficult characteristics compared to existing algorithms.

Combined distance control system and Stop&Go function in the Audi A8

Viewed in isolation, the potential of radar-sensor technology has been more or less exhausted. For its adaptive cruise control system Audi has therefore introduced multi-sensor monitoring of the area surrounding the vehicle — a combination of radar, video and ultrasonic systems. This networking provides a basis for extending the distance control system by including a stop-and-go function. The Federal German Army University in Munich here describes how the extremely sensitive, safety-relevant drive-off assistant was subjected to thorough examination using test subjects.

Kombination von Abstandsregelsystem und Stop&Go-Funktion im Audi A8

Das Potenzial eines einzelnen Radarsensors fur die Darstellung von Abstandsregelsystemen ist annahernd ausgeschopft. Audi setzt deswegen beim Adaptive-Cruise-Control-System im neuen A8 erstmals auf eine Uberwachung des Umfeldbereichs mit mehreren Sensoren. Die Kombination und Vernetzung von Radar-, Video- und Ultraschallsystemen bildet die Basis, das Abstandsregelsystem um die Funktion Stop&Go zu erweitern. Dieser sensible Bereich unmittelbar vor dem Fahrzeug und die Wechselwirkung mit dem Fahrer machte umfangreiche Probandenversuche notwendig, wie eine Studie der Universitat der Bundeswehr Munchen beschreibt.