Integrated ABS And Active Suspension Control Of Cars

Anti-lock braking system (ABS) and active suspension system play an important role to enhance vehicle handling and stability, traveling comfort and safety. In recent years, scholars and vehicle manufacturers both at home and abroad studied the integrated control of anti-lock braking system (ABS) and active suspension. An integrated controller of ABS and active suspension system is built on the basis of the sliding mode and H∞control theory. The specific content of this paper is as follows:Through the vertical wheel load in ABS, ABS and active suspension system is integrated. In this paper, a single wheel braking model and a quarter-car model are built. The ABS aims at getting the optimal slip rate of the wheel and advancing braking performance. The active suspension control system aims at improving suspension performance as well as the braking force while braking. To getting optimal control performance, the integrated controller is designed on the basis of the sliding mode and H∞control theory. The controller of ABS using sliding mode variable structure control, Sliding mode domain and variable structure control law are designed. In the design of the sliding mode domain, the slip rate deviation is selected as slip plane. In the design of the variable structure control.law, the constant velocity approach rate is selected to weaken chattering. The controller of active suspension using H∞control, the road surface disturbance is selected as uncertainly disturbance of outside to active suspension. The condition of closed-loop stability of active suspension system in non-disturbance is given, system performance for uncertainly disturbance is analyzed, and then the controller of active suspension is designed.The simulation results show that when in normal driving condition, the Body Acceleration, the Suspension Working Space and the Dynamic Tyre Displacement were effectively inhibited, and the vehicle’s ride comfort were significantly improved; While in braking condition, the integrated controller can not only effectively prevent the wheel being locked, significantly shortening the braking distance and braking time, but also can improve the vehicle’s comfort.