Fuzzy robust non-fragile control for nonlinear active suspension systems with time varying actuator delay

The active suspension systems have attracted increasing attentions because of its advantages in improving automotive dynamic performance. This paper focuses on the fuzzy robust non-fragile H2/H infinity control problem for the nonlinear active suspension system with the time-varying actuator delay and control uncertainty. Firstly, a Takagi-Sugeno fuzzy suspension model is established to describe the highly nonlinear components in the suspension system. Then, a series of linear matrix inequalities are derived based on a novel parameter Lyapunov function to guarantee the asymptotic stability of the suspension systems. Also, a fuzzy H2/H infinity controller is derived for the proposed fuzzy suspension model with the parallel distributed compensation method. Thirdly, a co-design criterion is proposed to obtain the fuzzy controller with the time varying delay and control uncertainty simultaneously. Finally, both simulations and experiments are carried out to demonstrate the effectiveness and robustness of the proposed controller.