Stability analysis and fuzzy smith compensation control for semi-active suspension systems with time delay

This paper investigates the problem of stability analysis and fuzzy-smith compensation control for semi-active suspension systems with time delay. The dynamic system of the suspension system with time delay is first formulated in terms of control objectives, such as ride comfort, road handling, and suspension deflection. By using the Lyapunov stability analysis, the necessary and sufficient condition of the critical time delay for the semi-active suspension is derived, and the numerical computation method of solving the asymptotic stability area for this suspension system is presented. Then, our work focuses on designing a Fuzzy-Smith predictive controller to satisfy suspension performance requirements. The control law adopted here is based on the smith predictive control principle, which ensures the control accuracy and stability of a time-delay suspension system. In order to overcome the challenging issues of the model uncertainties of input time delay, a Fuzzy-Smith predictive controller with time delay is established for the semi-active suspension. Furthermore, simulation and test results for the semi-active suspension are provided to demonstrate the effectiveness and feasibility of the proposed method.