Researches On Distributed Fault Estimation Observer Design Of Multi-agent Systems

Intelligent agent system is an independent and autonomous system,which can perceive the environment by sensors,autonomously act on the environment by effectors,and autonomously plan and select execution strategies,which greatly improves the work efficiency in engineering and has been widely used in practical engineering.The multi-agent system is composed of several agents,which can accomplish the tasks that cannot be accomplished by a single agent through mutual cooperation.Compared with traditional systems,multi-agent systems are more complex and prone to failure.Because the multi-agent system is a system in which the agents cooperate with each other to accomplish a goal or an independent goal,it will affect the other agents if one agent fails and cause the whole multi-agent system to fail to complete the work.In order to solve the above problems,fault detection and estimation techniques are widely used in multi-agent systems.This paper uses the function of Lyapunov stability theory and robust linear matrix inequality(LMI)techniques,the multi-agent system are studied the_?robust performance,distributed fault estimated observer can effectively estimate failure type and size when multi-agent system under fault condition,and guarantee the stability of the system.Based on the previous research,the distributed intermediate fault estimator is introduced to eliminate the matching condition of the observer and further improve the performance of fault estimation.The main work of this paper is summarized as follows:(1)The design of distributed fault estimation observer for multi-agent systems with model uncertainty is studied.Firstly,relative output estimation error is defined based on directed communication topology.Then a new distributed fault estimation observer is designed based on the built adjustable parameters to realize simultaneous estimation of state and fault.Based on_?pole assignment method,the feasible gain of distributed fault estimation observer is calculated.Finally,the effectiveness and feasibility of the proposed method are verified under two conditions,with and without disturbance.(2)A class of multi-agent system fault estimation problem based on intermediate estimator is studied.Different from the work in(1),a new distributed fault estimation method of intermediate fault estimator is proposed,which eliminates the limitation that most existing fault estimation methods need to satisfy the matching condition of the observer.Based on the properties of fault distribution matrix,an intermediate estimator is designed to estimate both state and fault.By constructing a new Lyapunov function which includes both the original system state and the intermediate estimation variables,the sufficient conditions for the existence of the distributed fault estimator and the gain matrix of the distributed fault estimation observer are obtained.The effectiveness of the proposed method is analyzed in two cases which are satisfying the observer matching condition and not satisfying the observer matching condition.Finally,the work done in this paper is summarized,points out some problems and further development direction in the theoretical research on distributed fault estimation of multi-agent systems and predicts the future research work.