The maximum coefifcient of friction is an important parameter for evaluating the stability of a vehicle. The knowledge of this parameter is therefore especially important for vehicle stability control. The main problem is to detect when the tire force reaches its maximum and the tire starts to skid. This may result in an unstable driving situation. This paper concentrates on lateral dynamics including lateral tire forces and tire slip angles. Two methods for the online estimation of the lateral maximum coefficient of friction between road and tire of a passenger vehicle are presented and compared: The first method is based on a gradient search and delivers accurate results with a small time-delay, while the second method is based on a stochastic classification with confidence intervals and almost non existent time delay. The methods are applied to and validated with measurement data. Method 1 finds myy, max with a gradient search including the Highway Safety Research Institute (HSRI) tire model. Method 2 calculates the probability of a data point belonging to predefined tire curves. Method 2 reacts immediately to a change in the surface, but can only reach four different values of the maximum coefficient of friction. A remaining bias can not be avoided. Method 1 is very flexible and can be used at any road surface. For the sake of robustness the adaption parameter limits the speed of convergence. Both methods require only little computational effort and can be implemented in real time systems.
Comparison of two methods for the estimation of the maximum coefficient of friction in a cornering maneuver of a passenger vehicle
2008
6 Seiten, 9 Bilder, 1 Tabelle, 13 Quellen
Conference paper
English
MAXIMUM FRICTION COEFFICIENT ESTIMATION SYSTEM AND MAXIMUM FRICTION COEFFICIENT ESTIMATION METHOD
European Patent Office | 2023
|MAXIMUM FRICTION COEFFICIENT ESTIMATION SYSTEM AND MAXIMUM FRICTION COEFFICIENT ESTIMATION METHOD
European Patent Office | 2023
|British Library Conference Proceedings | 1998
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