On control strategy of automatic transmission starting process

In a bid to research the starting process and improve the gear performance, the control of clutch in the starting process of a hydro-mechanical automatic transmission is analyzed. For this purpose the dynamic model of vehicle during starting process is built and analyzed in detail. Then a control strategy of starting process for automatic transmission is proposed, that is, fuzzy adaptive control at initial phase of quick oil charge, fuzzy adaptive control at torque phase and increment type PID adaptive control at inertia phase. Finally, the ECU is developed, and the control strategy has been verified on a heavy duty vehicle loaded with seven-gear AT. The starting process can be classified into starting by torque converter and starting by clutch. The test result shows that the control strategy is reasonable and effective.