Combination of active braking and semi-active suspension systems to improve the roll and yaw vehicle stability

Abstract

This paper presents a combined use of active chassis systems to enhance vehicle roll and yaw stability using semi-active suspension and active braking systems. The designed active braking system based on sliding mode control reduces the probability of vehicle rollover by decreasing the longitudinal velocity and lateral acceleration. Also, a semi-active suspension is proposed through fuzzy control method to improve the vehicle roll stability, which attenuates the effect of lateral acceleration on roll angle and roll rate. The lateral load transfer ratio is selected as the rollover index based on roll angle and lateral and roll accelerations. A vehicle dynamics model is built in the ADAMS environment, which includes subsystems of steering, braking and front and rear suspension, tire model and body. Also, the nonlinear characteristics of tires, bushings, springs and dampers are considered in the model. So, it can accurately express the dynamics performance of the vehicle. The control algorithm is evaluated under step steer and lane change maneuvers utilizing MATLAB and ADAMS co-simulation. Simulation results show that the proposed system with combined controllers can effectively improve the vehicle yaw stability and the rollover prevention compared with the only active braking and semi-active suspension systems.