ADAPTIVE DIRECT PRESSURE SHIFT CONTROL FOR A MOTOR VEHICLE TRANSMISSION

摘要

A method of adaptively correcting the operation of a shift control system for a motor vehicle multiple speed-ratio automatic transmission involves regulating the operation of a fluid-operated torque-establishing device (28,30,32,34) associated with a specified speed ratio in the transmission (10). Shifting from a currently engaged speed ratio to the specified speed ratio includes a preparation phase during which fluid is supplied to the torque-establishing device for a predetermined time to fill the same in preparation for torque transmission, and a completion phase during which further fluid is supplied to the device to initiate and progressively increase the transmission of torque therethrough. …The change in transmission input speed due to the initiation of torque transmission through the torque-establishing device is identified and used to detect the occurrence of an overfill or an underfill condition. The predetermined time is adjusted based on such detection so as to adaptively compensate for sources of error which degrade the shift quality by causing an overfill or an underfill condition.