Patent ID: 6966861

Claim:
A shift control method for an automatic transmission provided with a primary shift portion and a secondary shift portion, comprising: (a) starting shift control for the secondary shift portion by determining control start timing for friction elements of the primary and secondary shift portions based on vehicle operating conditions, if a shift signal is output, at the point of the output of the shift signal, and if shift control for the secondary shift portion is detected, starting shift control for the primary shift portion, and then determining a primary shift portion target change rate for feedback control of the primary shift portion and a secondary shift portion target change rate for feedback control of the secondary shift portion; (b) performing feedback control of the primary shift portion based on a comparison of a change rate of a difference between an input speed and an output speed of the primary shift portion and the primary shift portion target change rate, and the feedback control of the secondary shift portion based on a comparison of a change rate of a turbine speed and the secondary shift portion target change rate; and (c) completing a shift of the primary shift portion, then completing a shift of the secondary shift portion.