Cooperative Control of Multi-Time-Scale Agent Networks Under Digraphs

Abstract

This paper addresses cooperative control for a class of multi-agent networks. An interesting feature of such network is that each agent possesses the characteristic of multi-time-scale. By developing the relative states or the relative outputs based consensus protocols, some well-conditioned consensus criteria in terms of linear matrix inequalities are derived successively based on the ε-strict Lyapunov function. Compared with undirected graphs or strongly connected digraphs in existing works, a more general digraph that it contains at least a directed spanning tree is considered herein. Moreover, a fully distributed consensus protocol with time-varying coupling strength is proposed to avoid using global information. Finally, the obtained theoretical results are validated by two examples including standard and nonstandard agents.

Proportional integral observer‐based robust fault‐tolerant consensus for nonlinear two‐time‐scale‐agent systems with heterogeneous sensor faults

“…Remark Different from some existing works on consensus of multi‐time‐scale‐agents systems, 31–37,40 where external disturbances or sensor faults are not taken into account, besides, the global information of the communication topologies is need to implement the proposed consensus protocols, such as References 34 and 36, in this paper, the distributed PI observer‐based consensus protocol is proposed to achieve robust FTC issue of a class of nonlinear two‐time‐scale‐agent systems with external disturbances and sensor faults. By using adaptive control method, the presented consensus protocol can be implemented in fully distributed manner without using the global information of the communication topologies.…”

“…Remark It is worth noting that in absence of faults, the consensus problem for MASs with two‐time‐scale agents has been studied in References 31–44, while the robust FTC problems for linear two‐time‐scale‐agent systems with homogeneous sensor fault has been solved in our previous work 45 . In this article, we will go beyond those existing works to the situation that nonlinear two‐time‐scale‐agent systems subject to heterogeneous sensor faults.…”

“…Recently, many works have been reported to address the consensus issue of two‐time‐scale‐agent systems 31–44 . For examples.…”

“…Motivated by abovementioned analysis, this article aims to solve robust FTC issue for nonlinear two‐time‐scale‐agent systems with external disturbances and heterogeneous sensor faults. The main contributions of this article are stated as follows:Compared with the related works 31–44 on the consensus of two‐time‐scale‐agent systems, where disturbances or sensor faults are not taken into consideration, a comprehensive solution is proposed in this paper for solving the robust FTC issue of nonlinear two‐time‐scale‐agent systems subject to external disturbances and heterogeneous sensor faults. Compared with some proposed consensus protocols, such as References 33,34,36,37,39, which use the agent's and its neighbors full states and the global information of the communication topologies among agents, in contrast, a new decentralized PI observer‐based robust FTC protocol is proposed herein to simultaneously estimate the system states and heterogeneous sensor faults and to improve the robustness of the underlying system. Moreover, the proposed consensus protocol can be implemented in fully distributed manner since it is independent of the global information of the communication topology. Some well‐conditioned sufficient conditions on constructing both the proposed decentralized PI observer and FTC protocol are given, respectively.…”

“…Compared with the related works 31–44 on the consensus of two‐time‐scale‐agent systems, where disturbances or sensor faults are not taken into consideration, a comprehensive solution is proposed in this paper for solving the robust FTC issue of nonlinear two‐time‐scale‐agent systems subject to external disturbances and heterogeneous sensor faults.…”