Inventors:
Dara Monajemi - Lansing MI, US
Mark David Kieliszewski - Lake Orion MI, US
Todd J. Thor - Byron MI, US
Assignee:
GM Global Technology Operations LLC - Detroit MI
International Classification:
G07F 7/00
Abstract:
A method for controlling the torque phase of a clutch-to-clutch power downshift in a vehicle includes determining, during a near-sync boost (NSB) state of the power downshift, a synchronization speed. The method includes estimating, via a controller, a feed-forward clutch pressure that holds a speed of the turbine at the synchronous speed, and then ramping a clutch pressure command to the oncoming clutch to the calculated feed-forward clutch pressure. Closed-loop proportional-integral-derivative (PID) control is initiated over the clutch pressure command during the NSB phase in response to a predetermined PID activation event. A vehicle includes an engine, transmission, torque converter, and a controller. The controller has a processor and memory on which instructions embodying the above method are recorded. Execution of the instructions by the processor causes the controller to execute the method.