Abstract:

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.

Key words: mechanics, high-power automatic transmission, clutch oil charging, proportional solenoid, throttle opening