Distributed Cooperative Control Research Articles

Attack-Resilient Distributed Cooperative Control of Virtually Coupled High-Speed Trains via Topology Reconfiguration

Attack-Resilient Distributed Cooperative Control of Virtually Coupled High-Speed Trains via Topology Reconfiguration

Model‐free learning‐based distributed cooperative tracking control of human‐in‐the‐loop multi‐agent systems

AbstractThis article studies the model‐free learning‐based distributed cooperative tracking control of human‐in‐the‐loop multi‐agent systems in the presence of an active leader. The core role of human‐in‐the‐loop is to use the ground station to send control commands to the non‐zero control input of the leader, and then directly or indirectly control a group of agents to complete complex tasks. Meanwhile, three essential demands including the completely unknown system model, the control objective obtained optimally, as well as no initial admissible control strategy requirement, are satisfied simultaneously. It is worth emphasizing that the relevant results only satisfy one or two demands at most, which are essentially not applicable to this problem. In this article, a model‐based human‐in‐the‐loop learning algorithm is first presented to achieve the optimal tracking control, as well as the convergence of the proposed learning algorithm is proved. Then, a bias‐based data‐driven learning algorithm is proposed, which provides the potential opportunities to overcome the difficulties caused by the above‐mentioned three demands. Finally, the validity of theoretical results is testified by a numerical example.

Distributed Cooperative Control Strategy for Stable Voltage Restoration and Optimal Power Sharing in Islanded DC Microgrids

Conventionally, voltage regulation and economic dispatch in DC microgrid are performed at different time scales, which cannot keep the distributed generators (DGs) at the optimal operating point in real time. In this paper, a novel distributed cooperative control strategy is proposed to synchronously achieve stable bus voltage restoration and optimal power sharing in islanded DC microgrids. The proposed strategy breaks the constraints of hierarchical control strategies, and incorporates the objectives of voltage regulation and economic dispatch into a distributed cooperative control framework to eliminate average bus voltage deviation and minimize total power generation costs in real time. The stability of the proposed strategy is verified by eigenvalue analysis and steady-state analysis. Furthermore, the concept of “incremental cost (IC) margin” is introduced in cooperative control considering capacity constraints to avoid the converter output power violation and performance degradation. Finally, the MATLAB/Simulink simulation and StarSim HIL experimental results verify the effectiveness and robustness of the proposed strategy in an islanded DC microgrid under various testing scenarios.

Distributed Cooperative Control of BESSs in AC and DC Hybrid Microgrid and Its Energy Internet Paradigm

An AC and DC hybrid microgrid, which inherits advantages of AC and DC microgrids and discards some disadvantages, is considered to be the most promising power network structure and gradually applied in the community. Usually, the AC subgrid and the DC subgrid are interconnected by Bidirectional Interlink Power Converters (BILPCs). Besides, in view of the different droop characteristics of AC subgrid and the DC subgrid, it is necessary to design a suitable distributed secondary controller for an AC and DC hybrid microgrid. Accordingly, this paper proposes a flexible and scalable distributed control framework for an AC and DC hybrid battery energy storage system (ADHB) with BILPCs in an Energy Internet (EI) paradigm. An ADHB governed by multi agent systems via a cloud server can reach the State-of-Charge balance, proportional power sharing, frequency and voltage restoration. The proposed control framework provides the group play-and-plug by adding or removing an inter-MASs interaction link. For a single BILPC in an ADHB, active/reactive power, frequency and voltage are adjusted by an AC BESS. For the parallel BILPCs in EI, a decentralized secondary control scheme is proposed. Communication delay issues and stability are analysed. Then, the relevant simulation results verify the correctness of the proposed scheme.

A Communication Encryption-Based Distributed Cooperative Control for Distributed Generators in Microgrids under FDI Attacks

A Communication Encryption-Based Distributed Cooperative Control for Distributed Generators in Microgrids under FDI Attacks

Optimized Distributed Cooperative Control for Islanded Microgrid Based on Dragonfly Algorithm

This study introduces novel stochastic distributed cooperative control (SDCC) in the context of island microgrids (MGs). A proportional resonant (PR) controller and virtual impedance droop control in stationary reference frames are employed in cooperation with distributed averaging secondary control optimized by the dragonfly algorithm (DA). The suggested approach demonstrates the capability to achieve mean-square synchronization for the voltage and frequency restoration of distributed generators (DGs) to ensure efficient active power sharing. Therefore, a sparse communication network has been used to avoid data congestion and reduce the need for extensive communication and information exchange. The proposed system offers an instinctive compromise between voltage regulation and reactive power sharing. A conventional centralized secondary control with PR droop control is simulated for performance evaluation and comparison purposes. In this study, empirical evidence is demonstrated to support the MG’s ability to confront communication failure and its ability to work reliably during plug-and-play operations.

Distributed Cooperative Control of Singular Multi-agent Systems Based on Fuzzy Logic Approach

Distributed Cooperative Control of Singular Multi-agent Systems Based on Fuzzy Logic Approach

Convex Temporal Convolutional Network-Based Distributed Cooperative Learning Control for Multiagent Systems.

Due to its great efficiency, scalability, and inclusivity, distributed cooperative learning control has gotten a lot of attention. For complex uncertain multiagent systems, it is challenging to model the uncertainties and exploit the cooperative learning ability of the systems. To address these issues, we proposed a novel convex temporal convolutional network-based distributed cooperative learning control for uncertain discrete-time nonlinear multiagent systems. A new concept of using a convex temporal convolutional network (CTCNet) is proposed for estimating the uncertain agent dynamics in a cooperative way. Unlike previous methods that require adjustment of network weights for different control tasks, the proposed CTCNet can map the high-dimensional input-output space into a deep space spanned by basis features that represent the inherent properties of the system, so it has good robustness for different tasks. Consequently, to improve the control performance, a CTCNet-based distributed cooperative learning control method that shares learned knowledge through the communication topology among adaptive laws of CTCNet is proposed. Furthermore, the asymptotic convergence of system tracking errors to an arbitrarily small neighborhood of the origin is strictly proved. Finally, the simulation results are given to illustrate that our suggested method has higher control accuracy, stronger robustness, and anti-interference ability than the existing methods.

Bumpless transfer distributed adaptive backstepping control of nonlinear multi-agent systems with circular filtering under DoS attacks

This paper studies the problem of resilient distributed cooperative control for a class of uncertain nonlinear multi-agent systems (MASs) under Denial-of-Service (DoS) attacks. To avoid repeatedly differentiating the discontinuous communication signals caused by the DoS attacks in the backstepping procedure, a new circular switching filter is constructed. Compared with the existing results, the circular switching filter can sufficiently improve the tolerance capacity for the DoS attacks in the sense that the DoS attacks can be tolerated as long as the network under attacks is intermittently connected. To address the issue of discontinuity of the switching controller, a bumpless transfer controller is further proposed by smoothing the discontinuous communication signals based on an artificial time delay mechanism. Simulation results illustrate the effectiveness of the proposed control schemes.

Multi-agent based distributed cooperative control of air-conditioning systems for building fast demand response

The utilization of air-conditioning systems for fast demand response is particularly valuable in addressing urgent power balance requirements, owning to their large electricity consumption and inherent energy flexibilities. Limiting the number of operating chillers has proven to be a cost-effective means for direct load control in many studies. However, the conventional feedback control fails to distribute the limited cooling supply evenly, resulting in inherent uneven temperature rises among individual air-conditioned spaces when using this direct load control. To tackle this issue, a distributed cooperative control approach is put forward in this research. The proposed control is achieved based on a multi-agent system (i.e., valve agents and damper agents) in a self-organizing way. Each agent performs on-site control using the collected information of its own and its neighbors in a distributed architecture. The validation tests demonstrate that the proposed control approach is capable of efficiently managing the uneven temperature increases in different zones/spaces of the building. During the demand response event, a significant reduction of 2,562 kWh electricity is achieved, accounting for 19.7% of the electricity consumption using the conventional control.

Research on Dynamic Modeling and Distributed Cooperative Control Method of Dumbbell-Shaped Spacecraft

Research on Dynamic Modeling and Distributed Cooperative Control Method of Dumbbell-Shaped Spacecraft

Distributed Cooperative Control of Offshore Wind Farms Integrated via MTDC System for Fast Frequency Support

This paper proposes a distributed cooperative control (DCC) scheme of offshore wind farms (OWFs) integrated via the multi-terminal direct current (MTDC) system for fast frequency support. The DCC scheme employs the consensus algorithm to share the frequency support burden among offshore wind turbines (WTs) suitably. The proposed DCC scheme can exploit the kinetic energy of all WTs adequately while ensuring the security by employing the consensus state index and changing droop control coefficients adaptively. After the frequency support, the asymptotic recovery scheme is proposed at the leader WT for smooth rotor speed re-storage, and other WTs will follow the leader to recover and reduce the second frequency drop. Besides, to realize the fast frequency support, the communication-free estimator is employed to estimate the onshore DC voltage using offshore local measured signals. Case studies are carried out on MATLAB and OPAL-RT real-time simulation platforms, respectively. Different control schemes are compared to elaborate the performance of the proposed DCC scheme considering the parameter uncertainty and noise disturbance.

Fuzzy-Based Robust Precision Consensus Tracking for Uncertain Networked Systems With Cooperative–Antagonistic Interactions

In bipartite consensus tracking (BCT) tasks for nonlinear multiagent systems, stochastic disturbances and actuator faults are regarded as essential factors that hamper effective controller formulation and tracking precision improvement. To address these difficulties, we design an improved finite-time performance function (FTPF) for a fuzzy fault-tolerant distributed cooperative control scheme to achieve finite-time robust precision BCT tasks for nonlinear multiagent systems. The parameter selection range of the improved FTPF is relaxed, which renders systems to achieve better transient performance. Benefitting from stochastic Lyapunov stability theory, it is shown that all signals of systems are semi-global uniformly ultimately bounded in probability, and bipartite consensus errors can satisfy the arbitrary precision with probability in the predefined time. Finally, to verify its effectiveness, the proposed control scheme is applied to BCT tasks of a group of vehicles, which manifests anticipated control performance under various uncertainties.

Distributed Cooperative Control of Redundant Mobile Manipulators With Safety Constraints.

In this article, the distributed cooperative control problem of redundant mobile manipulators is investigated. A novel method is proposed to solve the problem by integrating formation control with constrained optimization, which not only transports the object along a reference trajectory in a distributed manner but also obtains the dexterous joint postures and end-effector displacements under safety constraints for collision avoidance. For the constrained optimization, the cost function and safety constraints are designed to quantify the mobility and manipulability of mobile manipulators, and collision-free working ranges with the object and obstacles, respectively. A discontinuous projected primal-dual algorithm with damping terms is proposed to solve the constrained optimization problem, providing the joint postures and end-effector displacements, which minimize the cost function and satisfy safety constraints. For the formation control, a finite-time control law, guided by end-effector displacements from the primal-dual algorithm, is developed in order to transport the object by establishing a prescribed formation and moving its centroid to track the reference trajectory. The cooperative manipulation is therefore achieved by the proposed method, which is further validated through numerical simulations.

Design of Distributed Cooperative Control for Multi-Missile System to Track Maneuvering Targets

Design of Distributed Cooperative Control for Multi-Missile System to Track Maneuvering Targets

Containment-Based Distributed Cooperative Control of Microgrid Clusters: Accurately Constraining the Bus States of Loads and Microgrids

Containment-Based Distributed Cooperative Control of Microgrid Clusters: Accurately Constraining the Bus States of Loads and Microgrids

Distributed Cooperative Control for Multi-UAV Flying Formation

Distributed Cooperative Control for Multi-UAV Flying Formation

Distributed Cooperative Control of Multiple UAVs in the Presence of Actuator Faults and Input Constraints

A distributed cooperative control algorithm of multiple unmanned aerial vehicles (UAVs) with directed topology is investigated in this brief. To overcome the actuator faults and external disturbance, incremental sliding mode formation controller is developed to realize the distributed coordination of the UAVs system, where an adaptive mechanism is utilized to deal with the chattering problem. Moreover, to reduce the adverse influence of input saturation, an auxiliary system is introduced to regulate the control signals. It is shown by Lyapunov method that the stability of the proposed algorithm can be guaranteed. A numerical example is given to illustrate that all follower UAVs can track the leader UAV.

Droop-Free Distributed Cooperative Control Framework for Multisource Parallel in Seaport DC Microgrid

In this article, a novel distributed cooperative control framework is proposed to solve the problems of unbalanced load current sharing and bus voltage deviation in seaport DC microgrid. This framework without droop control, and a novel droop-free cooperative controller is constructed to achieve current sharing and voltage regulation goals. Each distributed generator (DG) transmits information based on a sparse communication network, and uses a discrete dynamic consensus algorithm (DCA) to complete the accurate estimation of a virtual average state variable containing voltage and current information. In addition, a current limiting function adapted to DCA is designed to avoid control failure and prevent the converter output currents from exceeding the rated value. Finally, the influence of boundary weight, communication delays, and calculation delays on the system stability is analyzed, and a seaport DC microgrid simulation model and StarSim HIL experimental platform are built. The results show that the proposed control scheme can achieve average bus voltage restoration and proportional load current sharing within the allowable range of communication delays and calculation delays, and has prominent plug-and-play capabilities.

Distributed Control of Parallel DC–DC Converters Under FDI Attacks on Actuators

The parallel connection of DC-DC converters requires the development of an appropriate control strategy that regulates load voltage and shares current amongst participating converters. This paper proposes a resilient and robust cooperative distributed control approach that simultaneously ensures voltage regulation and balanced current sharing in parallel DC-DC converters in the presence of false data injection attacks on control input channels. Based on analytical tools from network control and Lyapunov stability theory, concise stability certificates are derived. The proposed cooperative distributed control strategy guarantees resilience against unknown bounded attacks on the actuators of DC-DC converters and the robustness to uncertainties in load parameters and the physical parameters of converters. Furthermore, the control design for each converter does not require any knowledge about the number of participating converters. The detailed simulation and experimental results verify the satisfactory performance of the proposed method in voltage regulation and balanced current sharing in parallel converters, as well as resilience to bounded false data injection attacks.