Vehicle Safety and Comfort Control base on Semi-Active Suspension

This paper proposes a novel control strategy adjusting damper force of semi-active suspension to improve vehicle performance, including comfort performance considering both vertical vibration and roll motion during a gentle turn on uneven road, yaw tracking capability during a shaper turn, and rollover avoidance during a fierce turn. The coupled roll and yaw dynamics model and quarter suspension model are firstly established. Considering road unevenness is the main factor which causes vertical vibration and discomfort, a simple method to evaluate road unevenness with vertical acceleration of sprung mass is proposed. The coupled roll and yaw dynamics model is simplified to a prediction model with lower computational cost, and then an MPC controller is designed. Three different cost functions of comfort, yaw tracking and rollover avoidance respectively are designed, and their switching strategy is proposed according to priorities. Simulation results show that control strategy proposed in this paper is effective to reduce discomfort, overshoot of yaw rate and risk of rollover.