Adaptive tracking control of vehicle suspensions with actuator saturations

This paper presents an adaptive tracking controller design approach for vehicle active suspensions to deal with the existence of input saturations aimed at providing superior ride comfort and stabilizing the attitude of the vehicle. A quarter-car vehicle active suspension system is considered in this paper with the nonlinear springs and piecewise linear dampers. Theoretically, a saturated adaptive tracking controller is synthesize to achieve an arbitrarily good disturbance rejection capability at steady-state in the presence of input saturations and uncertainties. Furthermore, the performance analysis of the closed-loop systems is given by rigorous mathematical derivations. Finally, extensive simulations and comparisons are performed to illustrate the proposed approach with typical periodic road input. The obtained results show that the designed controller can achieve good suspension performance despite the existence of control saturations.