Coordination strategy between AFS and ASB with fault-tolerant mechanism for ground vehicle

Abstract

In order to improve the performance of ground vehicle equipped with the active front-wheel steering and active stabilizer bar, the coordination for the two systems has been researched. A layered functional framework is proposed: the upper controller coordinates yaw motion with a designed Fuzzy proportional–integral–derivative controller algorithm correcting the outputs of active front-wheel steering and active stabilizer bar; for the middle subsystems, an ideal steering ratio is designed with the Sigmoid function to achieve the active steering, and a sliding mode algorithm is designed to reduce the roll angle; the bottom actuators achieve the control target from the middle layer. In addition, the upper layer has a rebuilt fuzzy rule-based fault-tolerant mechanism that handles the failure of stabilizer bar actuators to guarantee the stability of roll and yaw motion. Finally, the simulation and rapid-control-prototype test for step steering show that the designed algorithm can ensure roll and yaw performance. In consideration of the accidental failure of active stabilizer bar actuators, by actively adjusting the coordinated rules, the system could overcome the contradiction of coupling control and still maintain yaw and roll stability, which improves the active safety.