越野车辆大功率AT换挡离合器充油控制

对越野车辆大功率自动变速器（AT）换挡液控系统进行了分析，研究了离合器充油过程，建立了离合器滑摩阶段充油油压数学模型，得出无油压传感器下换挡过程离合器油压控制规律。在实际换挡过程中，根据油门开度修改比例阀的控制占空比，以适应不同负荷下离合器结合油压的需要；根据离合器摩擦片转速差引入参数反馈，对比例阀占空比进行调节，以提高车辆换挡品质。最后进行实车试验，通过对缓冲油压的控制能实现良好换挡。

Oil Pressure Control for Shifting Process of Off-road Vehicle with High-power Automatic Transmission

A shifting hydraulic control system of high power automatic transmission(AT) was analyzed in detail, the changing of the oncoming clutch was researched, and on this basis, a mathematical model of the slipping phase was established. The regulation rule of master oil pressure was addressed without oil pressure sensor. In order to consist with the vehicle load, the duty cycle of proportional solenoid was modified according to the throttle opening in practice. PWM also need to regulate dynamically on the feedback of the speed change of the oncoming clutch for good shifting quality. The suitability of the proposed approach was  thoroughly verified on a heavy off-load vehicle.