Abstract: In an automatic transmission including first and second planetary gear sets and a plurality of friction elements, during an up-shift and a time after the up-shift, a hydraulic pressure of a released friction element is kept at a predetermined value corresponding to the biasing force of a return spring set in the control valve of the friction element for a predetermined time after the end of the up-shift. When a down-shift is carried out immediately after the above-mentioned up-shift, the engagement of the released friction element is rapidly carried out since the hydraulic pressure of the friction element is kept at the predetermined value.

Abstract: According to a shift control, a release element is released in such a manner as to allow an increase in the input shaft speed within a predetermined degree for a period of time, and subsequently an apply element is engaged during the period of time.

Abstract: A clutch-to-clutch shifting in an automatic transmission is disclosed. According to the present invention, a timing at which an off-going element is to be released after engagement process of an on-coming element has been initiated is determined in response to a derivative, with respect to time, of a revolution speed of a rotary element, i.e., an input shaft.