Research on a novel electro-hydraulic brake system and pedal feel control strategy

Abstract

The existing electro-hydraulic brake system does not consider the adverse effect of the failure of the brake pedal feel simulator on the function of the braking system and the driving safety of the vehicle. To solve the above problems, a novel electro-hydraulic brake system is proposed. Firstly, the structural scheme and the working modes of the system are analyzed, and the electro-hydraulic brake system model is established, and a control strategy for the controlling of the wheel cylinder pressure is put forward. Then, the pedal feel control strategy is studied, which can simulate arbitrary pedal characteristics by controlling the output torque of the motor. Moreover, for the failure of the pedal travel sensor, a pedal displacement estimation method is proposed based on the pressure sensor information of the front chamber of the master cylinder. And for the failure of the pedal feel simulation motor, the pressure of the front chamber of the master cylinder is controlled by adjusting the opening of the pedal feel simulation valve to realize the simulation of the pedal feel. The simulation results based on CarSim/AMESim/Simulink show that the proposed electro-hydraulic brake system has fast pressure response speed and quick pressure tracking accuracy. The pedal characteristics are essentially unchanged before and after the failure of the pedal feel simulation motor or the pedal travel sensor.