Method of operating a vehicle utilizing regenerative braking

摘要

A vehicle includes a powertrain system and a friction braking system, the powertrain system including a hybrid transmission operative in one of a fixed gear operating range state and a continuously variable operating range state to transmit torque between an input member and a torque machine and an output member coupled to a driveline. A method for operating the vehicle includes monitoring operator inputs to an accelerator pedal and a brake pedal, monitoring vehicle speed, maintaining the transmission in a present operating range state subsequent to the operator disengaging the accelerator pedal absent the operator engaging the brake pedal, transitioning the transmission device to a continuously variable operating range state subsequent to the operator disengaging the accelerator pedal and the operator engaging the brake pedal, executing regenerative braking by controlling the torque machine to react torque through the transmission to brake the vehicle through the driveline when the operator engages the brake pedal and the speed of the vehicle is greater than a first threshold, and disabling the regenerative braking when the operator disengages the brake pedal and subsequently reengages the brake pedal when the speed of vehicle is less than a first threshold and greater less than a second threshold.