Consensus Control Of Nonlinear Multi-Agent Systems With External Disturbances

In the past 20 years,multi-agent systems have always been one of the research hotspots in the field of control,and have broad application prospects in the fields of multi-agent systems,multi-sensor networks,intelligent transportation and smart grids.Consensus problem is the core problem of cooperative control of multi-agent systems.Its goal is to make all agents use local information to reach a consensus on a global information of common interest.Considering that the agents in engineering practice are mostly nonlinear systems,in the process of solving the consensus problem,the noise signal has a great influence on the system performance.In this paper,the consensus problem of nonlinear multi-agent systems with external disturbances is studied.The main contents are as follows:(1)Considering a class of nonlinear multi-agent systems with disturbance and input delay,a leader-following consensus distributed controller is designed,and the sufficient conditions for the system to solve the consensus problem are obtained.Firstly,a distributed observer is designed for each follower based on the relative output information under the directed communication topology,which can estimate the state information of the leader and provide distributed control information for each follower.Secondly,according to the output information and disturbance information of each follower,the classical observer is introduced to estimate the state information and disturbance information of the follower.On this basis,a distributed output feedback consensus controller is designed for the follower by using the truncated predictive control method.By selecting the appropriate Lyapunov function,it is proved that when the parameters in the controller satisfy certain linear matrix inequalities,the designed consensus control protocol can make the corresponding states of all agents reach consensus.The numerical simulation results show that with the increase of time,the corresponding states of all agents achieve consistency,and the distributed observation error,classical observation error and control input tend to zero.The designed controller is effective.(2)For a class of nonlinear multi-agent systems with disturbances generated by heterogeneous exogenous systems,a distributed controller is designed based on the disturbance observer,and the sufficient conditions for the solvable consensus problem of the system are given.For the disturbance generated by heterogeneous linear exogenous systems,a linear disturbance observer and distributed controller are designed.For the disturbance generated by heterogeneous nonlinear exogenous systems,a distributed controller based on nonlinear disturbance observer is proposed by using dynamic gain technique.By selecting two suitable Lyapunov functions,it is proved that the system achieves consensus tracking when the parameters in the controller satisfy certain inequality conditions.The numerical simulation results show that the error trajectory between the leader and the follower tends to zero,and with the increase of time,the estimated value of each agent disturbance can track its actual value,and the designed controller is effective.