Distributed Sliding Mode Control for Nonlinear Heterogeneous Platoon Systems With Positive Definite Topologies

This paper is concerned with the distributed control of vehicle platoons. The dynamics of each vehicle are nonlinear and heterogeneous. The control objective is to regulate vehicles to travel at a common speed while maintaining desired intervehicle gaps. The information flow topology dictates the pattern of communication between vehicles in the platoon. This information is essential to effective platoon control and, therefore, plays a central role in affecting the design and performance of platoon control strategies. Our key contribution is a unified distributed control framework that explicitly incorporates and supports a diversity of information flow topologies. Specifically, we propose a distributed sliding mode control (DSMC) framework for a class of generic topologies. The DSMC constructs the topological sliding surface and reaching law via a so-called "topologically structured function." The control law obtained by matching the topological sliding surface and topological reaching law is naturally distributed. The Lyapunov stability analysis is carried out for the closed-loop system in the sense of Filippov to cope with the discontinuity originated from switching terms. Moreover, a tradeoff between tracking precision and chattering elimination is discussed with a continuous approximation of the switching control law. The effectiveness of the DSMC for platoons is verified under four different topologies through numerical simulation.