Abstract: In order to research the shifting process and improve the shift quality, the shift system of Electronic Automatic Transmission is analyzed, and a dynamic model of the shifting process is set up. The shifting process is analyzed in detail and the law of shifting process is abstained and at the same time the rule of clutch oil charging /discharging is researched. Research shows it can improve the quality of shifting transient process by using different control strategies in different phases. Namely, it is necessary to use the adaptive control strategy by phases, which means the following shall be adopted successively in the shifting process: adaptive control of initial oil charging/ discharging, open-loop adaptive control and closed-loop adaptive control. Through comparison with an ideal reference model, the control parameters are modified on-line in real time and then stored in the electrically erasable programmable read-only memory (E2PROM). Before the beginning of next shift, the modified parameters are called for improving the shift quality. Through tests, the clutch oil charging /discharging process, open-loop control process and closed-loop adaptive control process are researched respectively. The results show that by using the control strategy, the shift quality can be improved.

Key words: Adaptive control, Automatic transmission, E2PROM, Shift quality, Shifting process