A Guidance Module Based Formation Control Scheme for Multi-Mobile Robot Systems With Collision Avoidance

This paper investigates distributed formation control of multi-mobile robot systems with collision avoidance. A novel guidance module based formation control scheme is established, which consists of two main parts. In the first part, on the communication network of the multi-mobile robot system, a distributed guidance module is constructed from some pre-designed virtual dynamics scattered in the robots' feedback loops. By using some proper distributed formation control methods and distributed observer techniques, some formation references are generated by the guidance module. In the second part, by taking these references as the tracking references, some tracking con-trollers are designed and assigned to the robots such that the robots' positions track their respective references asymptotically. A two-layer constraint mechanism is presented in the above controller design to limit both the formation references and the robots' tracking errors such that robots' collision avoidance is guaranteed. In this way, the multi-mobile robot system completes the desired collision-free formation control task. Compared with existing results, the method proposed in this paper has a better plug-and-play function and wider application scope, especially when the practical robots have tight encapsulations such that their pre-equipped tracking controllers cannot be arbitrarily redesigned. Moreover, under the proposed scheme, the asymptotic formation convergence is achieved by the robots without extra limitations on robots' initial states and the utilization of global information. Some simulations and an experiment are given to validate the effects of the proposed methods.