An Adaptive Fuzzy Controller for 1/2 Vehicle Active Suspension Systems

A decoupled adaptive fuzzy controller (DAFC) for active vehicle suspension systems is developed in this paper. Since each actuator in the active suspension system should simultaneously control the sprung mass acceleration for ride comfort and keep the suspension travel within the rattle-space constraint, there need a compromise between this two conflicting requirements. Here, the non-square MIMO active suspension system is decoupled into two time-scales separated square MIMO systems via the singular perturbation technique. The proposed DAFC is implemented on the active suspension system of a 1/2 vehicle rolling model test rig with 4 degree-of-freedom (DOF). The control structure of this MIMO model-free controller is derived from Lyapunov stability theory based on relaxing Kalman-Yacubovich lemma requirement to monitor the system for tracking a user-defined reference model. The experimental results show the control performance of the proposed DAFC and compared with that of the passive suspension systems.