A new nonlinear observer for tire/road distributed contact friction

In this paper we present a new nonlinear observer structure for estimating the tire-road friction force in a vehicle by use of only the known angular wheel velocity. The observer developed here is shown feasible for a more complex friction model accounting for the distributed nature of contact, and a modified observed is proposed relieving some uncontrolled necessary preconditions for observer convergence, of previous works in Canudas-de-Wit and Horowitz, [C. Canudas-de-Wit et al., 1999], and in Canudas- de-Wit et al.