Global Exponential Rendezvous Control of Nonholonomic Unicycle Vehicles with Directed Communication Topology

This paper studies the full-state rendezvous control problem of multiple nonholonomic unicycle systems. A distributed state feedback time-varying control law is derived by exploiting model transformation, input-output feedback linearization technology, linear cooperation control theory and graph theory. Based on the carefully constructed output-like variable, the input-output feedback linearization approach overcomes the underactuated control challenge, makes the choice of controller parameters independent of initial states of vehicles, and allows the linear control theory applicable, rather than using the Lyapunov method and hence requiring the information flow undirected. Stability analysis proves that all the unicycle vehicles globally exponentially converge to a common fixed location and orientation, provided that the communication topology is directed and having a spanning tree. A numerical simulation is implemented for five nonholonomic unicycle vehicles, demonstrating the effectiveness of the proposed control scheme.