Synchronization Approach to Formation Control of Mobile Robots from the Cluster Space Perspective

In this paper, a synchronization approach to solve the formation control problem for three differential-drive wheeled mobile robots from a cluster space perspective is studied. In order to solve the individual trajectory tracking task of each mobile robot while maintaining a desired formation, besides the controller at cluster level, another inner robot controller is implemented. With this, the robustness of formation keeping to perturbations is increased and motions of all mobile robots are synchronized. Based on Lyapunov theory, it is demonstrated that the proposed synchronization strategy guarantees that both the tracking errors and the synchronization errors of all mobile robots asymptotically converge to the origin. Achieving this, the cluster errors asymptotically converge to zero as well. Furthermore, the robots orientation errors exponentially converge to the origin. The control laws are experimentally validated, using a set of TurtleBot3 mobile robots; these results show the efficiency of the proposed scheme.