VEHICLE INTEGRATED CONTROL FOR STEERING AND TRACTION SYSTEMS BY MU-SYNTHESIS

This study aims at improving vehicle maneuverability in global turning motions including critical turning, by an integrated control strategy which coordinates steering and traction systems. The vehicle model expressing global turning motions has nonlinear dynamics, and this makes it impossible to apply the linear control theory directly. In this paper, the nonlinear vehicle model which also considers transient characteristics of tires is linearized by a nonlinear transformation. The vehicle yaw motion is expressed by a first-order linear model, and mu-synthesis is applied to the model. As a result, the integrated control strategy which compensates robust stability against perturbations generated under various driving environments is obtained. Some experiments indicate that the integrated control improves vehicle performance.