Loading patent…
AssigneeGeneral Motors Corporation
InventorsJeffrey Kurt Runde, Scott Thomas Kluemper, Scott E. Mundy
Estimating the term…
An improved downshift control for an automatic transmission optimized for sequential shifting achieves skip-downshifting to a target gear by shifting the transmission to neutral and controlling the engine output torque while the transmission is reconfigured to establish the target speed ratio. The engine torque control is designed to allow the transmission input speed to reach the synchronization speed for the target speed ratio at a desired time, and the shift is completed when the transmission input speed actually reaches the synchronization speed. The engine torque control is predicated on a modeled engine torque parameter, and the torque control includes an adaptive parameter for adaptively adjusting the torque control to ensure that the input speed reaches the synchronization speed at the desired time.
A method of controlling a power-on downshift of a motor vehicle automatic transmission from a current gear to a target gear, the transmission having an input shaft coupled to receive output torque from an engine, the method comprising the steps of:
Dependencies are inferred from the claim text.