Distributed Cooperative Control of Multiple Nonholonomic Mobile Robots

Abstract

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.

Smooth time-invariant control for leaderless consensus of networked nonholonomic systems

“…Modifying the first control scheme, the second saturated smooth time-invariant static control law is obtained, which not only achieves the global asymptotic consensus control but also satisfies the input saturation condition. Comparing to the related works, [19][20][21][22][23][24][25][26][27][28][29] the proposed control strategies are smooth and time-invariant. Comparing to the work of Zhai et al, 30 the second control law can realize the consensus goal in the presence of input saturation.…”

“…c Remark 2. Different from the existing time-varying or discontinuous controllers in the literatures, [19][20][21][22][23][24][25][26][27][28][29] which addressed the leaderless consensus/formation control problem of nonholonomic systems, the distributed controller (equation (11) or (13)) is smooth, timeinvariant, and static. The achievement of this relies heavily on the Lyapunov function V 1 constructed in equation (4).…”

Group consensus coordination control in networked nonholonomic multirobot systems

“…Theorem 1. Given that fV 1 ; V 2 ; Á Á Á ; V k g is an acyclic partition of G and that Assumptions 1 and 2 hold, then coordination control of group tracking consensus for NNMMRSs (1) can be realized under the control protocol (12) and the adaptive law (13) if and only if Assumption 3 is satisfied.…”

Multirobot Heterogeneous Control Considering Secondary Objectives

“…In related research, the concept of cooperation is generally interpreted in two different ways: Based on leader-follower and based on a virtual leader [12,13,14]. In the leader-follower consideration, one of the robotic mechanisms plays the role of leader complying with the tracking of the established path, while the other ones move relatively to the main robot.…”

“…It is not known of any work that has done something similar. Compared to references [8,9,14], the proposed controller uses a hierarchical control structure, in order to provide scalability to the system and at the same time, not saturate the processing unit, thus merging both the centralized and decentralized information processors. At a very high hierarchy level, a centralized computer is responsible for generating the control actions to achieve the primary and secondary objectives, while, at a local level, each member of the heterogeneous robotic set includes its own processing unity to achieve kinematic and dynamic control and also to provide feedback of odometric information, which is shared through wireless communications based on a data frame (assuming no constrains given by the environment).…”