Optimal control allocation for coordinated suspension control

This paper is concerned with applying techniques from L²-optimal control allocation for the coordinated stabilization and control of vertical vehicle dynamics (roll, pitch, and vertical motion) using active and semi-active suspensions. This is accomplished by designing appropriate high-level controllers and control allocators for multiobjective control. The equations of motion for the vertical vehicle dynamics are presented and high-level controllers are designed using techniques from sliding mode control. Optimal control allocators are then designed by way of quadratic programs with special attention given to the differences inherent in active and semi-active (MR damper) suspension systems. Finally, the control system is implemented using a computationally efficient active set algorithm and validated in simulation with a CarSim model of a Chevrolet Equinox. Simulation shows that the control system designed here substantially improves the vertical vehicle dynamic response in the case of both active and semi-active actuators.