Abstract: A shift control system of an automatic transmission, wherein first and second transmission sections capable of automatically switching gear stages independently are provided and the first and second transmission sections are shifted to thereby achieve multi-stage shifts, comprising: a device for starting a shift in the second transmission section after the start of a shift in said first transmission section; and a device for ending the shifts in the first and the second transmission sections in synchronism with each other. Even when the first and the second transmission sections are simultaneously shifted, satisfactory shift characteristics are maintained, and further, the suceeding shift control in the second transmission section is adaptively controlled in accordance with the result of the preceding shift, so that the best shift can be achieved regardless of variations in the respective transmission sections.

Abstract: A method and system for shift control in an automatic transmission for a vehicle, wherein, during shifting, engine torque is changed to thereby maintain the shift characteristics satisfactorily, and wherein at least engine torque control in association with 1st shifting is stopped when a 2nd shifting command is emitted before 1st shifting is completed. When only the engine torque control in association with 1st shifting is stopped, thereafter, only the engine torque control in association with 2nd shifting can be performed, so that unnecessary torque control can be dispensed with. Furthermore, when engine torque controls in association with not only the 1st shifting but also the 2nd shifting are stopped, an unnecessary change in the engine torque control can be dispensed with in the case of shifting in which the shifting operation is not substantially performed.

Abstract: A control system for an automatic transmission system for a vehicle is adapted to control a partial clutch condition of one of two friction engaging devices which are oppositely engaged and disengaged in shifting the transmission from one speed stage to another speed stage, the control being such as to engage or disengage the one friction engaging device gradually by repetitive incremental increase or decrease of actuating fluid pressure supplied to the one friction engaging device while repetitively watching the rotational speed of a rotational element in the transmission during small time intervals.

Abstract: In a shift control system of an automatic transmission, wherein the shift control system includes at least a first and a second transmissions capable of automatically switching speeds separately of one another, and the first and the second transmissions are shifted simultaneously or alternately, to thereby achieve multi-speed shifts, there is provided means for starting and completing changes in rpm for the shift of rotary members of the second transmission during the operation of changes in rpm for the shift of rotary members of the first transmission, particularly when the first transmission is low gear shifted and the second transmission is shifted simultaneously, whereby the automatic transmission as a whole is down shifted, so that the shift characteristics can be maintained satisfactorily.