Experimental study of dynamic look-ahead scheme for vehicle steering control

A popular automatic steering control approach for passenger cars is to decouple the yaw motion from lateral motion by using yaw rate feedback. It has been shown that by re-defining the control position at a frequency-dependent distance ahead of the vehicle, the yaw dynamics can also be decoupled. In this paper, open-loop experimental tests are conducted at different vehicle speeds to verify the effectiveness of this dynamic look-ahead scheme. A fully equipped Buick LeSabre sedan is utilized as a test platform in this experimental study. Both the vehicle yaw rate and lateral acceleration frequency response data are obtained in the experimental tests by applying frequency sweeping techniques at different vehicle longitudinal velocities. It is shown that a decoupled input-output vehicle dynamics can be obtained by applying the dynamic look-ahead scheme to the open-loop frequency response data.