Method and apparatus for optimizing braking control during a threshold braking event

摘要

A method minimizes a driveline vibration and reduces stopping distances in a hybrid electric vehicle (HEV) having a plurality of drive wheels, a friction braking system having antilock braking system (ABS) capability, and an electronically variable transmission (EVT) with two EVT modes. The method automatically shifts the EVT to a predetermined high speed/low torque EVT mode when the ABS is active and when a calibrated maximum deceleration rate is not exceeded. An HEV has a friction braking system with ABS capability and an EVT including a plurality of modes. A controller automatically activates the friction braking ABS in response to a threshold level of slip between the drive wheels and the road surface when the brake pedal is actuated. An algorithm automatically shifts the EVT into one of the high speed/low torque EVT modes when the ABS is activated and the calibrated maximum deceleration rate is not exceeded.