California Partners for Advanced Transportation Technology

This paper discusses fundamental issues in lateral control design for automatic steering of passenger cars within an Automated Highway System ( AHS). A detailed analysis using time and frequency domain tools together with physical insight into the vehicle dynamics is presented. Several design directions are investigated, both for look-down and look-ahead systems. In order to preserve the qualities of look-down systems, the concept of virtual look-ahead via additional yaw error and yaw rate error measurements is introduced. The authors conclude that proportional-type feedback design suffices if the lateral vehicle dynamics itself provide phase lead for stabilization. On the other hand, a phase lead controller is required for shorter look-ahead distances.