Model-free tracking control for vehicle active suspension systems

This paper is concerned with the nonsingular terminal sliding-mode (NTSM) tracking controller design approach for active suspension systems. The control objective of suspension systems is to provide superior ride comfort and stabilize the attitude of the vehicle within the suspension´s travelling range. During the control process, a time-delay estimation (TDE) is used in cancelling system nonlinearities, uncertainties, and disturbances by intentionally using time-delayed information. Thus, the proposed control approach not only assures fast convergence due to the NTSM, but also requires little knowledge about the suspension dynamics with the help of the TDE. Although its model-free characteristic, the proposed control method provides robustness against parameters variations and accuracy control simultaneously. The proposed approach is implemented into a numerical example and a case study on a nonlinear uncertain quarter-car active suspension system. The simulation results verify the effectiveness and potential of the proposed design techniques.