ADAPTIVE ROBUST CONTROL FOR ACTIVE SUSPENSION SYSTEM USING T-S FUZZY MODEL APPROACH

This paper presents an adaptive robust control method for electrohydraulic active suspensions using the Takagi-Sugeno (T-S) fuzzy approach. A T-S fuzzy model using the saturation issue as a constraint to the outer loop along with a reformed feedback controller that seeks to optimize the H-infinity performance is proposed. The feedback control gains are determined by transforming the resulting optimization problem into a linear matrix inequalities (LMI) solution issue using the parallel-distributed compensation method. To reduce the hydraulic energy consumption, these LMIs associated with the stability analysis, comfort performance and suspension stroke limit are constrained in a manner that makes the performance to be dependent on the perturbation size. Adaptive robust control (ARC) is adopted next to deal with uncertain nonlinearities and to ensure robustness such that the electrohydraulic system is capable of tracking the stipulated force more accurately, though the sprung mass or hydraulic parameters are changed. The effectiveness of the system and the improvements made are validated through simulations. It is found that the proposed T-S fuzzy model-based ARC active suspension control outperforms conventional backstepping control and passive suspension, in particular with respect to robustness and energy saving.