Patent ID: 6535809
Filing Date: 2003-03-18
Classification: B60K,B60T,B60W,F02D

Abstract:
A torque control for a vehicle having a powertrain driving at least one driven wheel, the vehicle also having at least one undriven wheel, the control comprising:wheel speed sensors responsive to the driven and undriven wheels; means responsive to the wheel speed sensors to determine an engine drag control mode; means responsive to the wheel speed sensor of the undriven wheel in the engine drag control mode to derive a vehicle speed; means responsive to the wheel speed sensors in the engine drag control mode to derive a target velocity lower than the vehicle speed by a predetermined target velocity difference; means in the engine drag control mode to derive a velocity error as the difference between the driven wheel speed and the target velocity; and means responsive to the wheel speed sensors in the engine drag control mode to derive and deliver to the powertrain a torque command for reducing the velocity error, whereby the driven wheel speed is controlled in closed loop to the target velocity.