Adaptive Velocity and Acceleration Control of Autonomous Vehicle Systems

This article proposes a combined adaptive velocity and acceleration control (CAVAC) law for autonomous vehicles in the presence of uncertainties and nonlinearities. In particular, the global asymptotic stability of the nonlinear vehicle system under the proposed adaptive velocity control is shown to hold without real-time estimation of the vehicle parameters. Moreover, the CAVAC law is shown to achieve the string stability against energy bounded disturbances, and ensures the required intervehicle spacing, crucial to avoiding collisions in vehicle platoons. The simulation studies illustrate the advantages of the CAVAC law for the autonomous vehicle platoon in dealing with the speed limit changes, in mitigating issues induced by merging-exiting, in suppressing energy bounded disturbances, and in improving collision avoidance. The experiments on an electric vehicle (EV) validate the effectiveness of the proposed control laws.