System and method for controlling a driveline in a hybrid vehicle

摘要

A system and a method for controlling a hybrid vehicle powertrain during a change from a two-wheel drive mode to a four-wheel drive mode is provided. In response to a request to couple the second pair of wheels to the powertrain, a driveline controller commands an increased torque from the electric motor to be applied to the first pair of wheels The increased torque from the electric motor is based on an AWD engagement torque of the second pair of wheels to counteract an engagement torque of a second pair of drive wheels before changing from the two-wheel drive mode to the four-wheel drive mode.

主权项

1. A hybrid vehicle being operable to change between a two-wheel drive mode and an all-wheel drive (AWD) mode, the hybrid vehicle comprising:
a powertrain including an electric-motor; a primary driveline having a primary pair of drive wheels to receive torque from the powertrain in a two-wheel mode; a secondary driveline having a secondary pair of drive wheels; an AWD connection device arranged to couple the powertrain to the secondary pair of wheels when an AWD mode is required; and a controller, in response to a request to change to the AWD mode, the controller configured to:
command the electric-motor to apply an increased torque to the primary driveline prior to changing to the AWD mode;engage the AWD connection device thereby coupling the secondary driveline to the powertrain and changing to the AWD mode, wherein the electric-motor applies the increased torque to the secondary driveline through the primary driveline while a speed of the secondary driveline is less than a speed of the primary driveline in order to quickly change to the AWD mode without decelerating.