电磁阀阶梯减压控制方法

为实现电磁阀减压过程的精确控制,提出阶梯减压控制方法,并对控制参数进行了试验标定。通过对电磁阀阀芯受力与电磁阀液压响应特性分析,指出可通过调节电磁阀压力控制状态和控制信号状态持续时间得到不同的压力变化率,为阶梯减压控制实现提供依据。电磁阀压力控制状态采用延迟开闭控制方法。电磁阀控制信号状态持续时间受压力变化速率和开关延迟现象的影响,其中影响压力变化速率的阀口流量系数,影响开关延迟现象的开启延迟时间与关闭延迟时间通过试验标定。借助试验台架,对电磁阀不同速率的压力变化试验进行测试,结果表明所提出的阶梯减压控制方法能够很好地跟随目标压力,试验偏差可以维持在1 MPa以内,控制精度高。

Stepped Decompression Control Method of Solenoid Valve

During the hydraulic control unit of ESC (electronic stability control) working process, the main function of the solenoid valve is to adjust the wheel cylinder pressure precisely. However, the linear control mode which can not maintain consistency of control accuracy is susceptible to the state of the hydraulic brake system and the working environment of the solenoid valve, therefore, the stepped decompression control method was proposed, and control parameters were calibrated to realize the precise decompression control. Based on the analysis of the hydraulic valve spool force and hydraulic response characteristics of solenoid valve, it was pointed out that the pressure change rate can be obtained by adjusting pressure control status and duration time of the signal state of solenoid valve to provide basis for the realization of stepped decompression control. The pressure control state of solenoid valve adopted the delay opening and closing control method, which can avoid the frequent switching of the pressure control state between the decompression state and the holding pressure state. The duration time of the solenoid valve control signal state was affected by the pressure change rate and the switching delay phenomenon, in which the flow rate coefficient of the valve port affected the pressure change rate, the opening delay time and the closing delay time affected the switching delay phenomenon were calibrated by the test. With the help of a test bench, different pressure increase rates were tested when the cylinder hydraulic pressure was decreased. Results show that the proposed stepped decompression control method can make the cylinder pressure follow the target pressure well and the bias of experiment data can be maintained within 1MPa. At the same time, the control method had high control precision.