Robust active control of an integrated suspension system
This chapter presents the study of robust active control of an integrated vehicle suspension system that consists of chassis suspension, seat suspension, and driver body models. This integrated system has five control inputs and ten control outputs and each control input may require different feedback signals and have different saturation limits. Taking the measurement available variables as feedback signals, an H∞ static output feedback controller is designed to improve vehicle ride comfort performance in terms of driver head acceleration under the constraints of actuator saturation, suspension deflection limitation, and road holding capability. The parameter uncertainties to the driver body are considered in the controller design procedure. The controller design conditions, which are expressed as linear matrix inequalities (LMIs), are derived by dealing with each control input separately under a common Lyapunov function so that a feasible solution can be found. Furthermore, force tracking control strategy is applied to implement the proposed control system using electrohydraulic actuators. The improvement of ride comfort is evaluated by using numerical simulations on the driver head acceleration responses under a typical road disturbance.