Vehicle high speed stability analysis through integrated control

Abstract

This paper extends the analysis of Yakub et. al [1], by suggesting an integrated control which includes an active aerodynamic control and differential braking control to enhance high speed vehicle dynamics stability. Two aerodynamic surfaces are attached to the roof of the vehicle and servo controlled separately in real time. A hierarchical control structure which is composed of an upper and a lower controller. In the upper controller, the additional yaw moment required for stability control is determined by sliding mode control with the consideration of driver inputs, vehicle dynamic and the limitation of road adhesion. In the lower controller, a control strategy is designed to coordinate differential brake and active aerodynamic control, and an optimal control allocation algorithm is adopted to distribute the brake pressure of each wheel. Two double lane change tests on dry and wet road performed to study the effectiveness of the control algorithm in Simulink simulation. The results show, the proposed control strategy can effectively improve the vehicle dynamics stability and tire workload usage.