Demonstration of integrated longitudinal and lateral control for the operation of automated vehicles in platoons

This paper presents the design and experimental implementation of an integr ated longitudinal and lateral control system for the operation of automated vehicles in platoons, The challenges handled in the design of the longitud inal control system include nonlinear vehicle dynamics, string-stable opera tion with very small inter-vehicle spacing, operation at all speeds from a complete stop to high-speed cruising, and the execution of longitudinal spl it and join maneuvers in the presence of communication constraints. The cha llenges handled in the design of the lateral control system include high-sp eed operation using a purely "look down" sensor system and lane changing wi thout transitional lateral position measurements. The paper also describes the design of an on-board supervisor that utilizes inter-vehicle communicat ion and coordinates the operation of the lateral and longitudinal controlle rs in order to execute entry and exit maneuvers. Extensive experimental res ults are included in the paper from the NAHSC(1) demonstration of automated highways conducted in August 1997 at San Diego, CA. The demonstration incl uded a closely spaced eight-car platoon operating continuously over several weeks, with passenger rides being given to visitors. The maneuvers demonst rated included starting the automated vehicles from complete rest, accelera ting to cruising speed, automated lane keeping, allowing any vehicle to exi t from the platoon with an automated lane change, allowing new vehicles to join the platoon and bringing the platoon to a complete stop at the end of the highway.