Adaptive fully distributed consensus for a class of heterogeneous nonlinear multi-agent systems

Output-Feedback-Based Adaptive Leaderless Consensus for Heterogenous Nonlinear Multiagent Systems With Switching Topologies

This article investigates the leaderless output consensus control problem for a class of nonlinear multiagent systems with heterogenous system orders and unmatched unknown parameters via output-feedback control. The interaction topology among the agents is undirected and jointly connected. Due to the heterogenous system orders and switching topology among the agents, the classical distributed adaptive backstepping-based control technique cannot be applied to solve the problem considered in this article. To solve this issue, a novel distributed reference system is first proposed for each agent, by using only relative outputs of the neighboring agents. Subsequently, a fully distributed reference system-based adaptive leaderless output consensus control scheme is designed via output-feedback control. A remarkable merit of the proposed control scheme lies in that precisely known nonlinear dynamics, system states, distributed parameter estimates, and the states of virtual reference system are no longer needed to be shared with neighbors. This implies that the communication burden can be effectively alleviated, and even the communication network can be replaced by some perception sensors. Finally, two illustrative examples are provided to verify the effectiveness of the proposed control scheme.

Adaptive fixed-time consensus for stochastic multi-agent systems with uncertain actuator faults

In this paper, we study the adaptive fixed-time consensus control for stochastic multi-agent systems (SMASs) with uncertain actuator faults. Firstly, a fully distributed adaptive consensus protocol and an adaptive fault-tolerant consensus protocol are proposed, respectively, to ensure that the fixed-time consensus of SMASs with actuator faults can be reached. Secondly, an adaptive fault-tolerant containment consensus protocol is further proposed for the SMASs by leveraging the signum function, and this protocol can effectively solve the containment consensus in the unbalanced communication network. Finally, some simulation examples are given to verify the effectiveness of our consensus protocols.

Robust event-triggered cooperative control of uncertain multiple Euler-Lagrange systems based on three kinds of random transformation topologies

In this paper, we consider the consensus of uncertain multiple Euler-Lagrange​ systems. Based on switching topologies, the time-varying delay compensation, event-triggered mechanism, and finite-time convergence are considered, which can satisfy the needs of an actual system. First, the nonlinear uncertainties of the system are well approximated by applying the neural-networked scheme. Second, the new event-triggered mechanism can avoid the influence of the limited signal bandwidth and effectively decrease the data transmission times. Third, an adaptive law is used to compensate for the model and external disturbances. Fourth, the proposed switching topology scheme can respond to different scenarios, including when some agents fail to suddenly connect with their neighbors, and meet a wider range of collaborative needs. The effectiveness and feasibility of the proposed technique are demonstrated in theorem analysis and simulations.

Event-Triggered Sliding Mode Neural Network Controller Design for Heterogeneous Multi-Agent Systems

A class of heterogeneous second-order multi-agent consensus problems is studied, in which an event-triggered method is used to improve the feasibility of the control protocol. The sliding mode control method is used to achieve the robustness of the system. A special type of general radial basis function neural network is applied to estimate the uncertainties. The event-triggered mechanism is introduced to reduce the update frequency of the controller and the communication frequency among the agents. Zeno behavior is avoided by ensuring a lower bound between two adjacent trigger instants. Finally, the simulation results are provided to demonstrate that the time evolution of consensus errors eventually approaches zero. The consensus of multi-agent systems is achieved.