Fault-tolerant Consensus Control Research Articles

Adaptive fault-tolerant consensus for a class of leader-following systems using neural network learning strategy

In this paper, the leader-following consensus problem of a class of nonlinearly multi-dimensional multi-agent systems with actuator faults is addressed by developing a novel neural network learning strategy. In order to achieve the desirable consensus results, a neural network learning algorithm composed of adaptive technique is proposed to on-line approximate the unknown nonlinear functions and estimate the unknown bounds of actuator faults. Then, on the basis of the approximations and estimations, a robust adaptive distributed fault-tolerant consensus control scheme is investigated so that the bounded results of all signals of the resulting closed-loop leader-following system can be achieved by using Lyapunov stability theorem. Finally, efficiency of the proposed adaptive neural network learning strategy-based consensus control strategies is demonstrated by a coupled nonlinear forced pendulums system.

Fixed-time fault-tolerant consensus control for multi-agent systems with mismatched disturbances

This paper investigates the fixed-time consensus problem for multi-agent systems. Different from the existing results, the mismatched disturbances and actuator faults are taken into account, moreover, the communication networks are considered to be directed. By introducing fixed-time observers to estimate the faults and disturbances, a new observer-based control protocol is designed for each follower system. Under this scheme, the consensus is proved to be achieved by employing a bi-limit homogeneity technique and Lyapunov theory, and the convergence time is independent of initial conditions. Finally, simulation results are provided to verify the validity of the proposed method.

Distributed fault tolerant consensus control for multi-agent system with actuator fault based on adaptive observer

This paper mainly investigates the consensus control problem of multi-agent system with actuator fault under the leader-follower topology structure. For actuator fault, the additive and multiplicative fault are also considered in this paper. It is worth noting here that for actuator fault we only consider follower agent. For other factors that can affect system functionality, the external bounded disturbance and nonlinear factor are considered for all agents. The main paper organization structure is as follows. Firstly, by constructing nonlinear adaptive fault observer, the estimated values of actuator multiplicative fault and the unknown upper bound of actuator additive fault are respectively obtained. Subsequently, based on the estimated value of fault observer, a distributed fault-tolerant consensus control protocol is proposed to solve the consensus implementation problem of multi-agent system in the case of actuator fault. Finally, the effectiveness of fault-tolerant consensus control algorithm is proved by a simulation example of multi-aircraft system.

Fault tolerant consensus control of multi-agent systems with switching topology

This work studies fault tolerant consensus control of multi-agent systems with switching topology. It is assumed that some agents in some intervals don’t receive information from their neighbors, but the overall communication topology remains jointly connected. Initially, additive input fault with one-side Lipchitz constraint is considered. Next intermittent failures in the transmission of data between agents and controller is discussed in control architectures of central and distributed. To achieve consensus in such conditions, Lyapunov functional method is used. Finally, to verify the developed approach, a numerical example will be given.

Fault‐tolerant consensus control of second‐order multi‐agent system based on sliding mode control theory

This paper mainly investigates the consensus implementation problem of multi-wheeled mobile robot system in the case of actuator additive fault and external disturbance. By constructing the traditional sliding surface, the adaptive law about the upper bound estimation of actuator fault is designed and a fault-tolerant consensus control algorithm for the second-order multi-agent system (MAS) in the case of actuator additive fault is proposed. Subsequently, the theoretical rationality of this algorithm is proved by Lyapunov-related theory. In addition, the authors also propose a solution for the chattering problem of the traditional sliding surface by adjusting the adaptive law of the upper-bound estimation of faults. Finally, the authors use a multi-wheeled mobile robot system to verify the effectiveness of fault-tolerant consensus algorithm proposed by this paper.

Fault-tolerant Consensus of Leader-following Multi-agent Systems Based on Distributed Fault Estimation Observer

This paper is concerned with the fault-tolerant consensus control problem for leader-following multi-agent systems with actuator faults and external disturbance. Firstly, by employing the relative output estimation errors with respect to the corresponding neighbours and the leader, a distributed fault estimation observer is constructed for each follower and the established global estimation error system is proven to be asymptotically stable. Secondly, based on the obtained fault estimation, the active fault-tolerant consensus control protocol for each follower is proposed with the utilization of the relative output measurements rather than the state of the systems. Under this control protocol, the actuator faults can be compensated and the influence of disturbance can be eliminated as well. Moreover, it is worth noticing that the process of designing the fault estimation observer and the fault-tolerant controller is separated and their performances are considered simultaneously to simplify the design procedures. Finally, an illustrative example is presented to demonstrate the applicability and the effectiveness of the obtained results.

Adaptive Fault-Tolerant Consensus for a Class of Uncertain Nonlinear Second-Order Multi-Agent Systems With Circuit Implementation

In this paper, a robust fault-tolerant consensus control strategy and its circuit implementation method are proposed for a class of nonlinear second-order leader-following multi-agent systems against multiple actuator faults and time-varying state/input-dependent system uncertainties. The faults of partial loss of actuator effectiveness and bias-actuators are considered without knowing eventual faulty information. The uncertainties are supposed to be structured and to satisfy integral quadratic constraints. The nonlinear dynamics of underlying systems are described by linear state-dependent functions based on the differential mean value theorem. By designing adaptive schemes and state-feedback control gains, a novel distributed control strategy is constructed to ensure the asymptotic consensus of agents in the presence of actuator faults, uncertainties, and nonlinear dynamics. The control strategy is further physically implemented based on the circuit theory. The efficiency of the developed control circuits is verified by a multiple coupled nonlinear forced pendulum system based on a circuit simulation software.

Neural network-based adaptive fault tolerant consensus control for a class of high order multiagent systems with input quantization and time-varying parameters

This paper studies the adaptive leader-following consensus control for a class of strict-feedback multi-agent systems. All the agents possess the quantized inputs, the time-varying unknown parameters and the actuator failures. By estimating the upper bounds of the induced uncertainties, the obstacles caused by discontinuous input quantization can be circumvented. Meanwhile, several distributed adaptive laws are established such that the coupled uncertainties caused by the actuator faults and the time-varying unknown parameters can be handled. Since the desired trajectory is only partly known, an adaptive compensating term is introduced in the control structure. Moreover, to deal with the completely unknown nonlinear functions, radial basis function neural networks (RBFNNs) are introduced for approximation and compensation. It is shown that the output consensus can be achieved and the boundedness of all the signals can be guaranteed. Finally, we show the efficacy of our theoretical results using a numerical example.

Consensus control for multiple AUVs under imperfect information caused by communication faults

Consensus control for multiple autonomous underwater vehicles(AUVs) with imperfect information due to communication faults is established in this paper. Two novel fault tolerant consensus control techniques are addressed with respect to leaderless multiple AUV systems and leader-follower multiple AUV systems. The proposed control architectures are constructed so that each AUV exchanges information with its neighboring AUVs, i.e. distributed consensus control strategies are emphasized to tolerate information transmission faults for multiple AUV systems. The simulation study is carried out to show the effectiveness of the proposed theoretical analysis.

Distributed Adaptive Fault-Tolerant Consensus Control of Multi-Agent Systems with Actuator Faults


 
 
 This paper presents an adaptive fault-tolerant control (FTC) scheme for leader-follower consensus control of uncertain mobile agents with actuator faults. A local FTC component is designed for each agent in the distributed system by using local measurements and certain information exchanged between neighboring agents. Each local FTC component consists of a fault detection module and a reconfigurable controller module comprised of a baseline controller and an adaptive fault-tolerant controller activated after fault detection. Under certain assumptions, the closed-loop system stability and leader-follower consensus properties of the distributed system are rigorously established. A simulation example is used to illustrate the effectiveness of the FTC method.