A novel cost effective method for vehicle tire-road friction coefficient estimation

The tire-road friction coefficient is critical to

vehicle longitudinal, lateral and roll dynamics and control

because tire is the only contact part between the vehicle body

and the road. However, direct measurement of tire-road

friction coefficient is impossible in practice. This paper

presents a novel cost effective method for vehicle tire-road

friction coefficient estimation. This method only needs the

measurements of the wheel angular velocity, the traction/brake

torque and the longitudinal acceleration, which are all

available from the commonly installed sensors in ordinary

passenger vehicles, and can be used to estimate the individual

tire-road friction coefficient. There are three steps in the

proposed method. Firstly, the longitudinal slip ratio is

estimated by using a nonlinear filter with the measured wheel

angular velocity. Then the tire longitudinal force is estimated

by using a Kalman filter with the measured traction/brake

torque and longitudinal acceleration. At last, the friction

coefficient is estimated by using the recursive least squares

(RLS) method and the results obtained from the first two steps.

Numerical simulations are provided to validate the

effectiveness of the proposed method. It is shown by the

simulation results that the proposed method is effective in

estimating the tire-road friction coefficient.