Patent ID: 8903607

Claim:
A lane tracking system for a vehicle having a front wheel and a rear wheel, the lane tracking system comprising: a front steering controller configured to rotate the front wheel of the vehicle through a front steering angle in response to a front steering torque command; a rear steering controller configured to rotate the rear wheel of the vehicle through a rear steering angle in response to a rear steering torque command; and a lane tracking processor configured to: determine a desired course of the vehicle along a roadway; estimate a trajectory of the vehicle based on sensed vehicle motion; compute an error between the determined desired course and the estimated trajectory; and provide a front steering torque command to the front steering controller, and a rear steering torque command to the rear steering controller, the provided front steering torque command and rear steering torque command being selected to minimize the computed error and being limited to not exceed a predetermined maximum torque; wherein one of the front steering torque command and the rear steering torque command is zero until the other of the front steering torque command and the rear steering torque command equals the predetermined maximum torque.