Shift control system for automatic transmission

摘要

The transmission is equipped with engaging devices in a gear transmission mechanism, and when up-shifting from a first gear position to a higher second gear position, oil pressure command value for an engaging device used in the up-shift is made up of an open control component, the gradient of which is determined based on input torque, and a feedback control component based on a target gear ratio. In order to prevent a shock during up-shift caused by releasing a foot from the accelerator pedal, the feedback control component is set to zero when the amount of change in the throttle opening is equal to or greater than a predetermined threshold value. As a result of inhibiting increase in feedback in order to make up for a tendency for oil pressure depending on an open control component to decrease as a result of the throttle opening reducing and input torque falling, increase of the oil pressure command value becomes smooth. Peaks of the output torque are therefore suppressed.