An Uniformly Stable Observer for Tire Friction Estimation During Braking Process

There are patents that consider some interesting characteristics as are [1] and [2] related with the pneumatic and in [3] the electrical elements for the rapid braking, in this paper, an uniformly stable observer for tire/road friction model estimation during braking process is proposed. In this observer the angular speed of the tire is taken as the output and it is used to estimate the internal friction state, the linear speed of the tire and the relative velocity of the vehicle [4]. It is proven that the state error of the observer applied to the nonlinear model is uniformly stable. The observer proposed is based on the solution of a Linear Matrix Inequality (LMI) equation [5]. A simulation shows the effectiveness of the suggested observer.