Patent ID: 7008344

Claim:
A control apparatus for controlling a torque phase of an up-shifting operation in an automatic transmission having a torque converter, an input shaft of the automatic transmission connected to a turbine runner in the torque converter, an output shaft of the automatic transmission, and plural friction engagement elements selectively engaged or disengaged to connect or disconnect the input shaft with the output shaft indirectly for establishing plural shaft stages, wherein when up-shifting from one shift stage of the plural shift stages to another shift stage an off-going friction engagement element of the plural friction engagement elements is switched from an engaged condition to a disengaged condition for reducing torque transmitted by decreasing a hydraulic pressure supplied such that the off-going friction element starts to slip, and an on-coming friction engagement element of the plural friction engagement elements is switched from a disengaged condition to an engaged condition for multiplying transmitted torque by increasing supplied hydraulic pressure such that the on-going friction element stops slipping, the control apparatus comprising: a slip amount calculating means for calculating a slip amount based upon a rotational speed of the input shaft and a rotational speed of the output shaft thereof; a judging means for judging whether or not the calculated slip amount is greater than a predetermined threshold value by comparison; a target slip amount calculating means for calculating a target slip amount, the target slip amount varied from the predetermined threshold value to a predetermined target value drawing an ideal trace for restraining a shift shock of the torque phase of the up-shifting operation; a disengaging side controlling means for starting to perform an integral-proportional feedback control so as to substantially match the calculated slip amount with the calculated target slip amount for restraining over rotation of the turbine runner due to the up-shifting operation when the calculated slip amount is judged to be in excess of the predetermined threshold value by the judging means; and an engaging side controlling means for increasing the torque to be transmitted to the on-coming friction engagement element in association with commencement of the integral-proportional feedback control.