Robust Synchronization Control For Multi-Agent Systems

Recently,the synchronization problem of multiagent systems has attracted considerable at-tention in systems and control community,due to its application to a wide range of problems,including sensor networks,rendezvous,formation control and flocking control.The performances of the agents can be modified by a control law,to perform collective behaviors,such as to reach synchronization about relevant variables of interest.The agents exchange information through a communication graph,which is a time-varying graph or a time-invariant graph.In the leader-following consensus problem,the leader's motion is independent of all the other agents and fol-lowed by them.The dynamics of individual agents in the network can be identical or non-identical.In a heterogeneous network of non-identical agents,output synchronization among all agents can be achieved via the theory of output regulation.This thesis focuses on the details of synchronization problem for the Multi-agents System(MASs).Based on the sampling-data control,adaptive control and robust output regulation con-trol,we design the distributed controller to guarantee the homogeneous and heterogeneous MASs achieve synchronization.Specifically,the main contribution of this thesis can be summarized as follows:(1)Firstly,we design a sampled-data controller that can ensure the MASs are asymptotically synchronous subject to actuators saturation.By constructing a novel time-dependent Lya-punov functional,we make full use of the available information about the sampling pattern.Additionally,the actuators saturation are taken into account in the form of the generalized sector bound condition;(2)For the case of delayed sampled-data control,we construct a novel functional based on the vector extension of Wirtinger's inequality.This new functional can lead to simplified and efficient stability conditions.Furthermore,two optimization problems to evaluate the max-imal allowable upper bound of the sampling intervals addressed as well.Finally,numerical example is employed to illustrate the effectiveness and merits of the proposed approach;(3)We investigate the output synchronization of a heterogeneous network of agents affected by parameter perturbations.We use the output regulation theory to solve this problem.The main result is the construction of the reference generators and the robust regulators,which can guarantee the outputs of the non-identical agents track the output of the leader;(4)We study the output synchronization problem for a heterogeneous network.Specifically,the non-identical followers are affected by parameter perturbations and controlled to achieve output synchronization with an uncertain leader.We use the adaptive control theory and the robust output regulation theory to solve this problem.The MASs can achieve globally asymmetrical and locally exponential output synchronization;(5)The problem of output synchronization is investigated for the heterogeneous network with an uncertain leader.It is assumed that parameter perturbations influence the non-identical linear agents,whose outputs are controlled to track the output of an uncertain leader.Based on the hierarchical structure of the communication graph,a novel control scheme is proposed to guarantee the output synchronization.The agents in the upper layers will be treated as the exosystems of the agents in the lower layers.The local controllers are constructed in a sequential order.It is shown that the output synchronization can be achieved globally asymptotically and locally exponentially;Finally,we give the brief summary for this research work and the future work at the end of this thesis.