A new method of static output-feedback H ∞ controller design for 5 DOF vehicle active suspension system

Abstract

In this paper, the static output-feedback control problem of 5 degrees of freedom (DOF) vehicle active suspension systems is investigated. A novel H∞ optimal controller is designed for this system to improve simultaneously ride comfort and handling ability. The actuator saturation, suspension deflection and tire deflection are considered in the controller synthesis. To minimize the seat acceleration, taking into account the vehicle body vertical acceleration and pitch acceleration, a new method for designing and solving static output-feedback H∞ optimal controllers is proposed. First of all, a 5 DOF half-vehicle active suspension including active seat system model is presented. Then a direct, easily solved and effective method for static output-feedback H∞ optimal control is presented. The controller is obtained by solving linear matrix inequality optimization problem and direct computation of related matrices. Finally, a numerical example is presented. The simulation results show that the controller proposed can achieve better performance compared with state feedback H∞ optimal controller and the validity of the design method is verified.