H∞ tracking for fuzzy systems with an application to four wheel steering of vehicles

This paper presents a control method design based on the multi-controller approach for a class of nonlinear systems in order to track a desired trajectory. The dynamic behavior of the nonlinear systems considered here is described by a convex interpolation of linear dynamic equations and it may approximate a large number of nonlinear systems. The proposed control method is based on the same idea by interpolating linear control laws but the goal of the control design is to solve two control problems: the stabilization problem as well as the tracking problem. We present results on the stability analysis and tracking performance of the proposed multi-controller approach by using H^∞ synthesis and linear matrix inequalities (LMI). A simulation example, which concerns the four wheel steering control of vehicles, is given to illustrate the control algorithms.