H∞ robust-performance control of decoupled active suspension systems based on LMI method

This paper is concerned with model decoupling and H_∞ robust-performance control of a vehicle active suspension system. Firstly, the full-vehicle suspension system with 7 degrees-of-freedom is decoupled into heave-pitch and roll-warp subsystems using linear transformations. Secondly, the uncontrollable mode in the roll-warp subsystem is removed using the derived geometrical constraint equation; Thirdly, based on the LMI method, robust H_∞ output-feedback controllers are designed for the decoupled suspension system. Finally, the system´s performance is evaluated by computer simulations, which demonstrate that the active suspension system has better ride and handling performance than the passive system, and the performance can be maintained despite significant levels of uncertainty in the actuator dynamics