轿车电液制动系统设计及性能试验研究

Design and performance experimental of vehicle electromagnetic-hydraulic braking system

针对车用缓速器体积大、质量重及安装困难等缺点,设计了轿车电液制动系统(EHYS)。通过合理地控制EHYS摩擦式液力制动系统与电磁制动系统的制动力矩,减少了液力制动系统的磨损,延长了液力制动系统的使用寿命,解决了轿车制动器涉水失效及热失效等问题;通过对EHYS同步附着系数分析以及地面附着条件定量利用下的电液制动过程分析,得到了轿车前后制动器制动力理想分配关系曲线及前后轴制动力分配系数控制曲线;采用滑膜变控制策略对EHYS制动过程进行了控制,并进行了台架试验和道路试验。研究结果表明:在滑膜变控制策略作用下,EHYS可根据不同制动强度选择制动工况,并通过控制EHYS中的电磁制动线圈通电电流实现防抱死控制,从而可靠地减小制动距离,确保制动安全。

Aiming at the shortcoming of the automobile retarder, such as large volume,big weight and installation difficulty, electromagnetic-hydraulic braking system(EHYS) was proposed. Through distributing vehicle braking torque and electromagnetic torque reasonably, abrasion of braking system was decreased, service life was prolonged, and the problem such as thermal failure and wading failure of vehicle braking system was solved. By analyzing the synchronous adhesion coefficient and ground attachment conditions of EHYS, the ideal braking distribution curve and control curve of four-wheel braking device were found. By using the approach of sliding model variable structure control velocity control on EHYS, the bench and road experiment was presented.The results indicate that EHYS could adjust the braking torque based on different braking force by sliding model variable structure control and realize the function of ABS by controlling the current intensity of coil in electromagnetic braking system, which could shorten distance effectively and ensures braking safety.