Integrated Control of Differential Braking and Active Aerodynamic Control for Improving High Speed Stability of Vehicles

摘要

In this paper, an integrated control strategy (ICS) is proposed to improve high speed dynamics stability of the vehicle by the integration of active aerodynamic control (AAC) and differential braking control (DBC). Two aerodynamic surfaces are attached to the roof of the vehicle and servo-controlled separately in real-time. A hierarchical control structure is used to design the proposed scheme, 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. A simplified magic formula tire model is used to describe the nonlinearity of the tires. Two double lane change tests on dry and wet road performed to study the effectiveness of the control algorithm in CarSim/Simulink Co-simulation. The results show the proposed control strategy can effectively improve the vehicle dynamics stability and tire workload usage.