Abstract:Abstract: The design of the electronic hydraulic brake system in general is lack of theoretical guidance. In this experiment, the structure and working principle of the electronic hydraulic brake system were analyzed in detail. Then the matching design method for the electronic hydraulic brake system based on safety feature was proposed on the basis of establishment of the mathematical model, including the design of power supply based on the hardware failure protection, the design of emergency brake circuit based on power supply failure protection, the design of the inlet and outlet valves based on the emergency braking requirements. The effectiveness of mathematical model was validated through the experiments, and the braking performance of electronic hydraulic brake system in both the common brake and hardware failure was analyzed. The hardware in loop test results showed that the booster response time of electronic hydraulic brake system was reduced when compared with the conventional hydraulic brake system under the normal braking. The electronic hydraulic brake system could control the wheel slip ratio in high adhesion road, low adhesion road and docking the road very well under emergency braking. Also, after using the accumulator brake vigorously for five times, the accumulator pressure was not less than the minimum system pressure in the case of electrical failure indicating that the design of accumulator met the requirements. In addition, the booster response time increased in the case of accumulator failure showing that although the motor pressure rated was higher than the system maximum working pressure but it had low flow rate. Furthermore, in the accumulator and the motor failure cases, the electronic hydraulic brake system still could provide part of the braking intensity which was higher than design required 3 m/s2 braking deceleration. Conclusions from the research included the accumulator should guarantee to complete several intensive braking under the condition of motor pump failure considering the demand of security features. The design objects of motor pump should give attention to its expected charging time and maintain automobile braking performance in case of accumulator failure. The emergency braking circuit should provide a certain amount of braking ability under the condition of accumulator and motor pump failure as a hardware redundancy of the electronic hydraulic brake system. Simulation analysis showed that the matching design method of the electronic hydraulic brake system based on safety feature can guarantee the automobile braking safety both in normal condition and hardware failure. At present there are still some problems worth further study. For example, how to adjust design parameters to control the effective volume of the accumulator not too big, the influence of system parameters such as the system maximum working pressure and the minimum working pressure on the braking performance of the electronic hydraulic brake system, putting forward the method to optimize the design parameters of the electronic hydraulic brake system to improve its braking performance and so on.