Patent ID: 7962267

Claim:
A control apparatus for an automatic transmission, the automatic transmission including an input member and a plurality of friction-engagement elements having a first friction-engagement element and a second friction-engagement element, and being adapted to change a rotational speed of the input member driven by an engine, by engaging at least one of the plurality of friction-engagement elements in accordance with a desired speed step, the control apparatus comprising: a target-value setting section configured to set a target rotational-speed difference between an input rotational speed and an output rotational speed of at least one of the first and second friction-engagement elements, to cause the input rotational speed to become higher than the output rotational speed, when a downshift by a changeover between the first friction-engagement element and the second friction-engagement element is carried out during a power-on running of vehicle, the first friction-engagement element being adapted to attain a before-shift speed step, the second friction-engagement element being adapted to attain an after-shift speed step; a total torque-capacity calculating section configured to calculate a total torque capacity necessary for the first and second friction-engagement elements to bring an actual rotational-speed difference between the input rotational speed and the output rotational speed of the at least one of the first and second friction-engagement elements to the target rotational-speed difference set by the target-value setting section; a distribution-ratio setting section configured to set a distribution ratio of the total torque capacity between the first and second friction-engagement elements; an individual torque-capacity calculating section configured to calculate individual torque capacities necessary for the respective first and second friction-engagement elements, on the basis of the total torque capacity calculated by the total torque-capacity calculating section and the distribution ratio set by the distribution-ratio setting section; and an engagement control section configured to control engagement states of the first and second friction-engagement elements in accordance with the individual torque capacities calculated by the individual torque-capacity calculating section, the total torque-capacity calculating section being configured to calculate the total torque capacity by adding a transmission input torque for being inputted to the input member, to a correction value calculated from a deviation between the target rotational-speed difference and the actual rotational-speed difference for feedback control.