Desired braking torque control based on a slip ratio for Vehicle hydraulic braking system

In order to deal with the security and stability of the vehicle in braking, as well as the unmeasurable vehicle speed, a design method based on slip ratio is presented for the desired braking torque by utilizing state observer. Simultaneously, a torque output tracking controller is designed for the hydraulic braking system based on the nonlinear mathematical dynamics model of a quarter of the vehicle and hydraulic brake system. In the controller design, adaptive technique is adopted to deal with the unknown road condition produced by tire structure, external interference and velocity factors. Both theoretical analysis and simulation results show that the proposed control scheme can guarantee the security and stability of the vehicle in braking process and achieve the desired braking effect.