Distributed Cooperative Control of Multiple Nonholonomic Mobile Robots

In this paper, the distributed cooperative control problem is considered for multiple type (1,2) nonholonomic mobile robots. Firstly, a local change of coordinates and feedback is proposed to transform the original nonholonomic system to a new transformed system. Secondly, a distributed controller for the transformed system is designed by using information of the intrinsic system and its neighbors to make the state converge to the same value asymptotically. Furthermore, it shows that the same value can be confined to the origin, which means that the problem of cooperatively converging to a stationary point of a group of nonholonomic systems can be practically solved. Finally, due to the communication delays are inevitable in practice, new distributed controllers for the transformed system are also proposed making the state converge to the same value or zero asymptotically with considering communication delays. The proposed methods are then extended to the case where the nonholonomic mobile robot needs to form a prescribed formation other than agreeing on a same value. The stability of the proposed methods is proved rigorously. Simulation results confirm the effectiveness of the proposed methods.