Automatic vehicle trajectory tracking control with self-calibration of nonlinear tire force function

Abstract

Trajectory tracking capability is important for automatic vehicle guidance. One difficulty for realizing accurate trajectory tracking is the requirement of knowing the tire cornering stiffness under linear tire force range or the nonlinear tire force function when tire force becomes large. In this study, the vehicle trajectory tracking problem is firstly formulated in the vehicle's local frame. Then an adaptive control methodology is adopted here to tune the discretized nonlinear cornering stiffness function. The method also has the advantage of avoiding the direct usage of vehicle's lateral velocity in generating the steering control signal. In the simulation result part, the performance of the method considering the nonlinear tire force effect is compared with a linear one. Simulation results in CarSim® illustrate that the proposed method considering the nonlinear tire force effect can show improved performance over the method only considers the linear tire force model.