Automatic transmission shift control based on torque phase detection using measured transmission input torque

Abstract

A system and method for controlling a vehicle powertrain having a transmission to improve shift quality to detect the start of a torque phase of the shift based on a measured transmission input shaft torque. A torque sensor provides a signal to a controller that monitors initial rise time of the measured transmission input shaft torque. The torque sensor may be implemented by a strain gauge, a piezoelectric load cell, or a magneto-elastic torque sensor. The system may include a vehicle powertrain having an engine, a transmission coupled to the engine via a torque converter and a controller configured to initiate torque phase control when the slope of the transmission input shaft torque exceeds a predetermined threshold after initiation of the shift preparatory phase.

Dependencies are inferred from the claim text.