线控制动系统踏板感觉模拟器设计与改进

设计开发一种线控制动（EHB）系统样机，选取不同过流孔径的踏板模拟器常闭电磁阀进行踏板行程-踏板力对比试验.结果表明：当将单个电磁阀直接接入踏板感觉模拟器回路时，随着制动力加载速度的提高，会产生实际制动踏板行程-踏板力关系曲线偏离目标曲线的问题，并且电磁阀孔径越小，偏离越大，借助于数学推导得出电磁阀过流孔径与踏板速度响应之间的理论关系.设计一种液压先导阀加入到踏板模拟器回路中，以提高系统通流能力和踏板速度响应，液压先导阀由原回路中的电磁阀控制.对改进的踏板模拟器回路进行仿真及试验，结果均表明：改进过的回路可较好地实现踏板行程-踏板力曲线精度，曲线受踏板力加载速度变化影响小，同时可使模拟器常闭电磁阀工作功耗更低，提高了系统的可靠性.
Abstract: A kind of electro-hydraulic brake system prototype was designed and developed. Some solenoid valves with different flow holes, as a switch of pedal feel emulator circuit, was tested in pedal stroke-force (S-F) curves contrast tests. Results show that there is bigger offset of pedal S-F curves from the target curve with the increase of actual braking force loading speed. The offset from target pedal S-F curves is bigger if the flow holes of the solenoid valves is smaller. The theoretical relationship between flow hole diameters of solenoid valves and barking force loading speed is mathematically derived. A hydraulic pilot valve was designed and added into the pedal feel emulator circuit to improve through-flow capacity of system and velocity response of braking pedal. The hydraulic pilot valve was controlled by original solenoid valve in circuit. The new revised pedal feel emulator circuit was simulated and tested. Results show that the new circuit has good pedal S-F curve accuracy, which is little susceptible to braking force loading speed, and at the same time the solenoid valve can work in lower power consumption which can improve the system reliability.