Cooperative Output Regulation Research Articles

Observer-based resilient cooperative output regulation for nonlinear multiagent systems with time-varying parameters and DoS attacks

This paper aims to address the cooperative output regulation (COR) problem of nonlinear multiagent systems (MASs) with time-varying parameters under denial-of-service (DoS) attacks. First, to address the challenges of unavailable leader signals and non-differentiability issue caused by the DoS attacks, a class of first-order low-pass filters is employed to develop a novel distributed resilient observer, which accurately estimate the exosystem state with the existence of high-order derivatives. Then, by viewing the output of observer as the reference signal, a distributed resilient controller is designed for each follower to address the reference-tracking problem. By introducing a smooth function with positive integrable time-varying function, novel adaptive laws are developed and incorporated with the controller design to effectively compensate for the unknown time-varying parameters. By utilising Lyapunov stability theory, the asymptotic convergence of output regulation error can be ensured. Finally, simulation results are conducted to verify the validity of the designed method.

Collisions-Free Distributed Cooperative Output Regulation of Nonlinear Multiagent Systems

Collisions-Free Distributed Cooperative Output Regulation of Nonlinear Multiagent Systems

An Internal Model Approach to Cooperative Output Regulation Over Switching Graphs

An Internal Model Approach to Cooperative Output Regulation Over Switching Graphs

Funnel-Based Cooperative Output Regulation Control for Uncertain Nonlinear Multiagent Systems Under Input Saturation

Funnel-Based Cooperative Output Regulation Control for Uncertain Nonlinear Multiagent Systems Under Input Saturation

Fully distributed dynamic event-triggered reliable COR of nonlinear MASs with communication link faults and actuator faults for directed graphs

The issue of fault-tolerant cooperative output regulation (COR) for nonlinear uncertain multiagent systems (MASs) under communication link faults (LFs) and actuator faults is investigated in this paper. This is the first attempt to study the fault-tolerant COR problem for the aforementioned MASs under directed graphs. To handle unknown LFs and avoid using global information, adaptive event-triggered (ET) observers are designed to estimate the exosystem state. That is, resilience against communication LFs is translated to distributed observer design. To overcome the “explosion of complexity” and obtain asymptotically stable results, dynamic surface control (DSC) techniques are introduced. Unlike existing linear DSC techniques that generate boundary layer errors, this paper introduces nonlinear filters with compensation terms into dynamic surfaces to eliminate boundary layer errors. Adaptive control laws that can achieve asymptotically regulated output are then developed based on the improved DSC techniques. It is shown that the developed control strategy can achieve fault-tolerant COR for the considered MASs. Additionally, the implemented dynamic event-triggered mechanism (ETM) ensures strictly positive minimum event-triggered intervals (ETIs) and avoids Zeno behavior. Finally, a practical simulation example reveals the effectiveness of the suggested scheme.

Distributed adaptive cooperative optimal output regulation via integral reinforcement learning

This paper studies the optimal cooperative output regulation problem for unknown linear multi-agent systems by the integral reinforcement learning technique. Existing results on this problem were obtained by a non-fully distributed learning process. In contrast, we propose a distributed learning algorithm over the jointly connected switching communication networks. Moreover, by modifying the existing algorithm, we reduce the computational cost and weaken the solvability conditions. Two numerical examples are used to illustrate the effectiveness of our approach.

Cooperative output regulation problem with faults based on adaptive event-triggered mechanism

This paper focuses on the cooperative output regulation issue of heterogeneous linear multiagent systems (MAS)s under directed graph, where there are communication link faults and actuator faults. Firstly, a novel adaptive event-triggered compensator is constructed to estimate the state of the exosystem in the presence of communication link faults. Then, dynamic event-triggered controller is constructed to compensate for the impact of actuator faults on system stability. Note that the novel dual event-triggered mechanisms are designed to reduce communication frequency, and the MAS does not show the Zeno behavior. Finally, simulation experiment is introduced to verify the validity of the proposed method.

Hierarchical containment control with cluster consensus for multiagent systems under directional three-layer topology

This paper investigates the hierarchical containment control with the cluster consensus behaviour for heterogeneous multiagent systems. Firstly, according to the investigated cooperative behaviour, the hierarchical containment error vector is formulated. Based on the cooperative output regulation, the hierarchical framework is developed such that the hierarchical containment error vector can be converged to zero. Secondly, since the directional three-layer topology breaks the assumption of directed spanning tree, the existing type of containment control law fails to reach the investigated hierarchical cooperation. To solve this issue, the cross-layer observer is designed to guarantee the convergence of hierarchical cooperation. Then, the novel hierarchical containment control law with the designed cross-layer observer is proposed to ensure that the cluster consensus behaviour can be reached in the convex hull. Moreover, by adjusting the defined hierarchical parameters, the global containment control performance can be improved. Finally, the numerical simulation is provided to demonstrate the effectiveness of the proposed hierarchical containment control law.

Controllability of heterogeneous multi-agent systems via cooperative output regulation

This paper investigates the controllability of heterogeneous linear multi-agent systems (MASs) based on the cooperative output regulation, in which the considered agents are of high-degree heterogeneity, including different dimensions, heterogeneous dynamics and nonidentical interactions varying with agent and its neighbors. A design framework is developed for nonidentical external input and interaction gains, with the help of the improved cooperative regulators and virtual triple. Some necessary and/or sufficient conditions are derived to ensure the controllability of MASs. The obtained controllability criteria require lower computational cost and are much easier to examine compared with directly performing the traditional controllability test on heterogeneous MASs. Furthermore, extended controllability analysis without regulation assumptions is also provided to illustrate the effect of interactions among diverse agents on the controllability. The effectiveness of theoretical results is substantiated finally by two examples: a 6-agents heterogeneous MAS and a practical MAS composed of heterogeneous aircrafts and vehicles.

Cooperative output regulation of heterogeneous multi‐agent systems under false data injection attacks

AbstractThis paper studies the cooperative output regulation problem for heterogeneous multi‐agent systems (MASs) subject to false data injection (FDI) attacks, which means the malicious cyber‐attackers may inject false data into the communication topology randomly. To ensure that each follower agent can track the leader agent accurately, we construct both an observer and a control law for each follower agent. Since the FDI attacks may exist in the communication network, a filter with an adaptive compensator, which can estimate attack signals dynamically, is equipped for each observer, such that the filter can neutralize attacks when malicious attackers launch attacks. Therefore, the cooperative output regulation can be achieved under the control law based on the observer no matter whether there exist attacks or not. Finally, a numerical example is provided for validating the theoretical results.

Fuzzy Cooperative Output Regulation for Open Nonlinear Multiagent Systems

Fuzzy Cooperative Output Regulation for Open Nonlinear Multiagent Systems

Quantized cooperative output regulation of continuous-time multi-agent systems over switching graph

Quantized cooperative output regulation of continuous-time multi-agent systems over switching graph

Preface

Hosted by Nanjing Tech University, China, the 2023 2nd International Conference on Aerospace and Control Engineering (ICoACE 2023) was held from 15th to 17th December 2023 in Nanjing, China. With ICoACE 2023, the conference series International Conference on Aerospace and Control Engineering (ICoACE) completed its second edition.The general topics of ICoACE 2023 fall into mainly four categories: 1) Aerospace Materials; 2) Aerospace Science and Technology; 3) Control Engineering; 4) Aerospace and Mechanics. Apart from the general topics, ICoACE 2023 attracted a number of papers related to aerospace and control engineering. Topics at the Conference include but are not limited to: Materials Failure Analysis and Prediction Prevention, Spacecraft Thermal Control Technology, Aerospace Computing, Combustion and Energy Conversion, Electric Automation, Drive Motor and Control Technology, etc.All papers were exhaustively reviewed by program committee members and peer-reviewers, who took into account the breadth and depth of the research topics that fall under the scope of ICoACE. The most promising and ICoACE mainstream-relevant contributions were selected from all the submissions for presentation and inclusion in this volume, which presents innovative original ideas or results of general significance supported by clear and rigorous reasoning and compelling new evidence, as well as methods.The Conference included three days of technical parts consisting mainly of keynote speeches, oral presentations, poster presentations and academic discussion. We were delighted and honored to invite Prof. Yan Wang (Nanjing University of Aeronautics and Astronautics, China), Prof. Mouquan Shen (Nanjing Tech University, China), and Prof. Wenfeng Hu (Central South University, China) to share their insightful ideas and mind-blowing researches as keynote speakers. Based on the research The Cooperative Control of Multi-Agent Systems with High Comprehensive Performance, Prof. Wenfeng Hu first introduced the event-triggered control strategies for multi-agent systems to reduce the communication burden among agents and talked about the brought challenging issues. Then, he addressed the consensus of homogeneous multi-agent systems and cooperative output regulation of heterogeneous multi-agent systems with event-triggering communication. Moreover, he presented the developed reset control strategies for multi-agent systems with second-order dynamics. Finally, an outlook on the new topics and trend for the cooperative control of networked control systems theory and techniques were given.We would like to thank all the keynote speakers, authors, program committee members and anonymous reviewers for their efforts in making ICoACE 2023 a Conference of the highest standard. We are also grateful to Journal of Physics: Conference Series, for its help in publishing this Proceedings of the Conference.The Committee of ICoACE 2023List of Committee Member is available in this pdf.

Fixed-time cooperative output regulation for second-order nonlinear multiagent systems with an unknown exosystem

This paper investigates the fixed-time cooperative output regulation (FTCOR) problem with unknown exosystem of second-order nonlinear multiagent systems. To solve this problem, it is necessary to ensure that each agent can obtain the reference trajectory originating from an unknown exosystem and reconstruct the solution of the regulator equation containing the exogenous signal and unknown parameter vectors within a fixed time, and the unknown exosystem makes it difficult to solve these two problems with existing tools. By using auxiliary filtering variables, we propose a fixed-time adaptive distributed observer (FTADO) and design a fixed-time distributed internal model (FTDIM) based on this FTADO. These two new tools ensure the solvability of the two problems just mentioned. Then, based on these two tools, we transform the problem into a fixed-time stabilization problem of a so-called augmented system. Through the backstepping technique, we propose a distributed controller that solves this fixed-time stabilization problem while relaxing the assumptions of similar references.

Improved Event-Triggered Prescribed-Time Cooperative Output Regulation for Nonlinear Multiagent Systems

Improved Event-Triggered Prescribed-Time Cooperative Output Regulation for Nonlinear Multiagent Systems

Event-triggered robust cooperative output regulation for a class of linear multi-agent systems with an unknown exosystem

This paper investigates the robust cooperative output regulation problem for a class of heterogeneous uncertain linear multi-agent systems with an unknown exosystem via event-triggered control (ETC). By utilizing the internal model approach and the adaptive control technique, a distributed adaptive internal model is constructed for each agent. Then, based on this internal model, a fully distributed ETC strategy composed of a distributed event-triggered adaptive output feedback control law and a distributed dynamic event-triggering mechanism is proposed, in which each agent updates its control input at its own triggering time instants. It is shown that under the proposed ETC strategy, the robust cooperative output regulation problem can be solved without requiring either the global information associated with the communication topology or the bounds of the uncertain or unknown parameters in each agent and the exosystem. A numerical example is provided to illustrate the effectiveness of the proposed control strategy.

Distributed Observer-Based Optimal Cooperative Output Regulation With Control Effectiveness Faults

Distributed Observer-Based Optimal Cooperative Output Regulation With Control Effectiveness Faults

Hybrid Event-Triggered Cooperative Output Regulation of Multiagent Systems With Unreliable Communication Link.

This article studies the event-triggered cooperative output regulation problem of heterogeneous multiagent systems with external disturbances and unreliable communication link (i.e., packet losses occur intermittently). A novel hybrid event-triggering mechanism (ETM) is proposed, which imposes a strictly positive lower bound for triggering intervals, and an internal variable with jump dynamics is introduced to design triggering condition. A hybrid model is constructed to describe the closed-loop system with both flow and jump dynamics. Then, based on the hybrid model, Lyapunov-based consensus analysis, hybrid ETM design, and robust performance analysis results are developed. Compared with the existing results, the minimum triggering interval (MTI) can be prespecified, and Zeno behavior is ensured to be excluded no matter there exist disturbances or not, which is useful for control implementation. Besides, the packet losses are allowed to be nonidentical, that covers identical packet losses as a special case. Moreover, the tradeoff between MTI and the number of maximum-allowable successive packet losses is explicitly given. Finally, simulation results are provided to show the effectiveness of the proposed method.

Prescribed-Time Cooperative Output Regulation of Heterogeneous Multiagent Systems

Prescribed-Time Cooperative Output Regulation of Heterogeneous Multiagent Systems

Robust Cooperative Output Regulation for Networks of Hyperbolic PIDE–ODE Systems

In this paper the robust cooperative output regulation problem for multi-agent systems (MAS) with general heterodirectional hyperbolic PIDE-ODE agents is considered. This setup also covers networks of ODEs with arbitrarily long input and output delays. The output of the agents can be defined at all boundaries, in-domain and may depend on the ODE state, while disturbances act on the agents in-domain, at the boundaries, the output and the ODE. The communication network is described by a constant digraph and if its Laplacian is reducible, then heterogeneous agents are permitted also in the nominal case. The solution is based on the cooperative internal model principle, which requires to include a diffusively driven internal model in the controller. The corresponding state feedback regulator design starts with a local backstepping stabilization of the coupled hyperbolic PIDE-ODE systems. It is shown that the remaining simultaneous stabilization of the MAS can be traced back to the simultaneous stabilization of the finite-dimensional cooperative internal model. Solvability conditions in terms of the network topology and the agents transfer behavior are presented. The new design method is applied to the formation control of a platoon of uncertain heavy ropes carrying loads to verify its applicability. Simulations confirm the synchronization performance achieved by the resulting networked controller.