Robust control design for active suspension system with uncertain dynamics and actuator time delay

The control performance of the vehicle will degrade due to the uncertain dynamics between the mathematical nominal plant description and the actual physical system. A robust control scheme is designed for an active suspension system so as to improve the system control performance. In the design of a robust control scheme, the real parametric uncertainties, as well as the structural uncertainty and time delay of the actuator, are taken into account, which is more realistic than the traditional control methods. Robustness performance and stability of the system are investigated and discussed in the paper. The μ synthesis controller is designed and compared with the H^∞ control algorithm as well as the traditional passive suspension system. The control performance is validate under two typical road excitation conditions including the random road and the speed bump road. Simulation results show the effectiveness of the proposed control schemes compared to a H^∞ approach.