Patent ID: 8900095
Filing Date: 2014-12-02
Classification: B60W,F16H,Y10T

Abstract:
1. A method of commanding a synchronous gear shift in a vehicle powertrain that includes an engine and a transmission having a plurality of ordered gears, the method comprising: receiving a request to shift from a third gear to a first gear, and skipping a second gear having a gear ratio between the gear ratio of the first gear and the gear ratio of the third gear; reducing a torque command to a predetermined value; opening a clutch disposed on an input shaft of the transmission to decouple the transmission from the engine; transitioning the engine from a torque-control mode into a speed-control mode; commanding the engine, while in the speed-control mode, to rotate at a speed dictated by the motion of the vehicle and the gear ratio of the first gear; closing the clutch to couple the transmission and the engine; and transitioning the engine back into the torque-control mode.