Abstract: A method for controlling a rate of change of speed ratios in a continuously variable transmission (CVT) includes sensing a vehicle speed, sensing an engine speed, and sensing a change in a position of an accelerator pedal. The method includes determining a desired engine speed based on said change in said position of said accelerator pedal, said vehicle speed, and said engine speed. The method includes increasing a target engine speed at a first rate to a predetermined value, wherein said target engine speed corresponds to a speed ratio. The method includes measuring a difference between said target engine speed that is held at said predetermined value and an actual engine speed, and increasing said target engine speed to said desired engine speed at a second rate when said difference substantially equals a predetermined threshold, wherein said second rate is less than said first rate.

Abstract: This invention provides a method for controlling a gear ratio in an automatic transmission of a vehicle. The method includes detecting a desired engine braking condition associated with the vehicle. Once the engine braking condition is determined, a decay factor is determined for reducing the gear ratio of the transmission. The decay factor maintains the gear ratio for a delayed period of time before gradually reducing the gear ratio over time. After determining the decay factor, the gear ratio of the transmission is controlled in accordance with the decay factor.