Shift control system and method for automatic transmissions

摘要

A shift control system for use in an automatic transmission which is connected to an engine and capable of changing the output torque of the engine during a shift. The automatic transmission includes first and second transmission assemblies connected in series to each other and each having a plurality of rotary components. The shift control system comprises: a shift timing decider for deciding whether or not the upshift of the first transmission assembly is resultantly delayed relative to the downshift of the second transmission assembly, when the automatic transmission is to be upshifted in its entirety by the upshift of the first transmission assembly and the downshift of the second transmission assembly; an engine torque controller for controlling the output torque of the engine during the shift; and an output device for outputting an instruction signal to the engine torque controller to reduce the output torque of the engine if the shift timing decider decides that the upshift of the first transmission assembly is resultantly delayed relative to the downshift of the second transmission assembly.