Improved Protocols and Stability Analysis for Multivehicle Cooperative Autonomous Systems

With increasing growth of vehicles, traffic congestion and safety deserve to be looked at more closely. Cooperative autonomous driving is an effective solution to reduce traffic congestion and ensure traffic safety. In this paper, cooperative autonomous control of multiple vehicles is considered to realize sharing the same roads without collusion with each other. Lane-following and braking control are two basic operations of cooperative driving. The objectives of lane-following are to make inter vehicles keep a safe spacing and run on the middle position of a lane. To reach the targets, two distributed control protocols are proposed in which we consider not only lateral control but also longitudinal control. The stability analysis is also shown for both the control protocols. Braking control is another basic operation for autonomous cooperative control. In order to make vehicles stop at the desired target stopping position (TSP), a new braking control protocol is also designed, and the convergence of which is analyzed and shown that, under three kinds of distinct braking control parameters, the position of the mass center of all vehicles exponentially converges to the TSP, and the velocity of the mass center of all vehicles exponentially converges to zero, which provide a guide for selecting the braking control parameters in real engineering applications. Moreover, the initial and limit conditions of position and velocity are discussed. Simulations demonstrate the validity and superiority of the proposed control protocols compared with existing approaches.