Adaptive consensus for high-order unknown nonlinear multi-agent systems with unknown control directions and switching topologies

Abstract

In this paper, we provide a comprehensive assessment of the consensus of high-order nonlinear multi-agent systems with input saturation and time-varying disturbance under switching topologies. The control directions and model parameters of agents are supposed to be unknown. Our approach is based on transforming the problem of consensus for a network that consists of high-order nonlinear agents to that of perturbed first-order multi-agent systems. The unknown part of dynamics is cancelled using radial basis neural networks. Nussbaum gains and auxiliary systems are respectively employed to overcome the unknown input direction and the saturation. Adaptive sliding mode control is used to compensate for the time-varying disturbance and the imperfect approximation of the developed neural network as well. Through Lyapunov analysis, it is shown that the overall closed-loop system maintains asymptotic stability. Finally, our approach is applied to a group of multiple single-link flexible joint manipulators to highlight better its merit.

A continuous distributed control algorithm for time‐varying networks of nonlinear agents with input saturation

“…In this section, we take the manipulator as an example. In order to illustrate the effectiveness of the proposed algorithms, five single-link flexible joint manipulators with DC motors are considered, 37 where the dynamics of the i-th one with input saturation are posed as…”

“…3. Compared to the related literature on consensus of agents with input saturation and UCDs, 37 where the network topology is time-varying with undirected or balanced directed graphs, in this work the network topology is described by the uniformly quasi-strongly -connected graphs, which includes the time-varying topology with undirected or balanced directed graphs as a special case. As we know, the communication network in this article is the mildest condition for high-order nonlinear agents with input saturation and nonidentical UCDs, which implies a major improvement.…”

Adaptive sliding mode control for disturbed multirobot systems performing target tracking under continuously time-varying topologies

“…The Lipschitz constants are l x ¼ 1:5 and l v ¼ 0:26. In the simulations, the continuously time-varying topology of the system is shown in Figure 3 Now, we conduct the simulation for tracking system under the effect of disturbances (25) and the sliding mode control law (9) without the adaptive part À jSj…”

“…Specifically, under switching topologies, an adaptive sliding mode control approach for multirobot systems is presented, in which the model parameters of high-order robots remain unknown. 25 The results are used to a set of flexible joint multiple single-link manipulators. An adaptive fixed-time distributed consensus protocol with switching topologies for consensus tracking of uncertain high-order multirobot systems is investigated.…”

Containment Control of First-Order Multi-Agent Systems under PI Coordination Protocol

“…Distributed coordination control of multi-agent systems has been an active research area for its widespread potential engineering applications including cooperative surveillance, sensor networks, spacecraft formation flying, etc. The most fundamental problem studied in coordination control is consensus problem [1][2][3][4][5][6][7][8][9][10][11] which means that each agent reaches an agreement based on the information from its relative agents. According to the different number of leaders in the multi-agent system, the consensus problem is generally divided into leaderless case [12,13], single-leader-follower case [14][15][16], and multipleleader-follower case.…”