Adaption strategy of power on down shift for automatic transmission

Automatic transmissions are being widely used on the vehicles. In order to compensate for the influence of build-to-build variations and life-cycle variations on automatic transmission, there should be an adaptive control in the control software in addition to the base control of the shifting process. As a main shifting condition, the power on down shifting process control was discussed in this paper. The relevant adaptive control strategy is proposed to obtain stable and consistent power on down shifting. Times of vehicle testing have been done which prove the feasibility and stability of this strategy. The applicability testing results with 20 cars show that more than 30% of the automatic transmission needs the shifting adaption, and the shifting process of these cars can be stabilized in the required range in the end. Therefore the adaption strategy of power on down shift proposed in this paper is necessary and feasible for the mass manufacture. It can compensate for the influence of build-to-build variations and life-cycle variations on shift quality.