SHIFT CONTROL APPARATUS OF AUTOMATIC TRANSMISSION FOR VEHICLE

摘要

PURPOSE: A shift control apparatus of an automatic transmission for a vehicle is provided to secure sufficient robustness with respect to disturbance though not having a control apparatus with high accuracy. CONSTITUTION: A shift control apparatus of an automatic transmission of a vehicle to which a torque is transmitted from an engine via a fluid coupling device, includes a plurality of hydraulically operated friction elements. A clutch-to-clutch downshift is carried out during coasting of the vehicle by releasing one of the friction elements as a release-side friction element and engaging another of the friction elements as an engagement-side friction element. The shift control apparatus comprises a speed difference detecting unit(128) detecting a difference between input and output rotation speeds of the fluid coupling device, and a minimal driving state controller(134) increasing an engine speed by a controlled amount based on the difference between the input and output rotation speeds detected by the speed difference detecting unit when the clutch-to-clutch downshift is carried out during coasting of the vehicle, so that the vehicle is brought into a minimal driving state in which the engine speed is slightly higher than the output rotation speed of the fluid coupling device.