LMI Based Nonlinear Observer Design for Estimating Tire-Road Friction Force

This paper deals with the problem of the robust tire-road friction force estimation. Tire-road friction is the most important piece of information used by active safety system. The friction coefficient between the tire and the road is exactly the kind of information which is very useful but is not directly measurable. To achieve the vehicle speed information and tire-road adhesion property is very important to the vehicle active safety control system. Since the friction is the main mechanism for the production of friction in the car, accurately describes the friction force generated at the interface between road and tire is very important and there are different methods for modeling tire road friction force. In this paper we propose structure a new nonlinear observer using linear matrix inequalities to estimate tire-road friction force, This did Using a suitable dynamic model, namely average lumped LuGre friction model for tire and and only with the angular velocity of the wheel that is measurable. Simulation results show that the observer well recognize various road conditions, and when the road suddenly changes from one type road to another road, error is very low and adapts well with road conditions. The proposed observer carries out a precise estimate from tire-road friction force, even when the road-tire friction characteristics the unknown and complex.

کلیدواژه ها:

friction ، estimation ، observer