Cooperative Target Localization And Circumnavigation Control Of Multi-agent Systems

In recent years,the cooperative target localization and circumnavigation control of multi-agent systems has attracted a considerable interest in various scientific communities due to its broad applications in national economy,military fields,and civil life,etc..In the research of specific application tasks,such as selfpositioning of agents in network system,phone localization in a cellular network,target circumnavigating and tracking,security and surveillance,etc.,all agents are required to locate the position of target,even agents are required to circumnavigate or track the target in some complex tasks.Moreover,many significant difficulties and challenges are posed to the design of circumnavigation control law and the analysis of the stability of systems in the case of the unknown position of target.Therefore,these lead to a rush in the research of the cooperative target localization and circumnavigation control of multi-agent systems.This thesis focuses on two main investigation topics: the cooperative target localization of multi-agent system based on a cooperative persistent excitation condition and the cooperative target localization and circumnavigation control of multi-agent systems in the case of limited information.By virtue of the concept of cooperative persistent excitation,the cooperative target localization problem of multi-agent system is investigated;combining the dynamic average consensus theory and localization technology,a multi-target circumnavigation control algorithm is proposed for multi-agent system;based on consensus method,a class of uniform circumnavigation control algorithm is proposed to solve the multi-target uniform circumnavigation control problem of multi-agent system.The main contributions of this thesis can be summarized as follows:1.The cooperative target localization problem of multi-agent system is investigated,where the target is static or dynamic.In order to reduce the traditionally defined persistent excitation condition to the cooperative persistent excitation condition,by virtue of graph decomposition technology,we design a new cooperative target localization algorithm,and show that the multi-agent system still can cooperatively locate the position of the target under the condition of connected topology.2.By virtue of the technology of bearing measurements,the problem of multi-target localization and circumnavigation of multi-agent system is investigated in the plane.Both stationary and slowly-moving targets are considered.Since the positions of targets are unknown,an estimator is designed to estimate the target position;then a distributed estimation algorithm is designed for each agent to cooperatively estimate the centroid of multi-target;and finally,based on the first steps,a circumnavigation controller is devised to guarantee that each agent circumnavigate all targets around the multi-target centroid with a desired radius.The convergence of the estimation algorithm and the stability of the circumnavigation controller are proved.3.The problem of uniform circumnavigation of multi-agent system is addressed.Different from the conventional circumnavigation control,the uniform circumnavigation task requires that all agents finally uniformly distribute on the same circle and perform the uniform circumnavigation task with the same angular velocity.The problem of single-target uniform circumnavigation of multi-agent system is first investigated when the position of target is known,and a new approach of design of uniform circumnavigation controller is proposed.Based on the technology of bearing measurements,the problem of multi-target uniform circumnavigation of multi-agent system is further considered for the case of the unknown target position.