California Partners for Advanced Transportation Technology

This report summarizes recent work done in the area of longitudinal control of a platoon of autonomous vehicles. As a prerequisite to controller design, a twelve state nonlinear model including an internal combustion engine, engine transmission dynamics, and tire friction characteristics has been developed. Two simplified models for simulation and controller design are presented. After outlining the control problem, two platooning strategies, based on spacing or headway criterion, are proposed. To solve the control requirements, decentralized nonlinear control strategies using throttle angle and brake torque control for a platoon were developed using a modification of the technique of Sliding Control and Input-Output Linearization. The quantities of primary concern are position and velocity tracking errors. Simulation results on multiple vehicle platoons demonstrate excellent tracking using the spacing-based controllers. The control strategies were implemented experimentally on the Integrated Platoon Control System (IPCS) during two and four car platoon testing.