Research On Equivalent-Input-Disturbance Based External Consensus Control Of Multi-Agent Systems

As a new interdisciplinary subject,multi-agent system can better solve the complex practical engineering problems that a single agent can not solve,and has a wide range of applications.In practical engineering,the stability and external consensus of multi-agent system are seriously affected by the nonlinear actuator,temperature,noise,wind and other external factors as well as the existence of uncertainty.In order to achieve high precision and reliable external consensus control,this paper uses equivalent input interference method to study the external consensus control of multi-agent systems under several kinds of special disturbances.The main research contents of this paper are as follows:(1)For multi-agent systems with actuator nonlinearity,a separation design method for multi-agent systems is proposed.By analyzing the nonlinearity of dead zone and gap and combining EID,the multi-agent system with actuator nonlinearity is described.According to the system control block diagram based on EID,an external consensus control protocol with nonlinear compensation is designed.By establishing the closed-loop system model,the external consensus control problem is transformed into the closed-loop system stability problem,and the stability and external consensus of multi-agent system are proved by using Hurwitz matrix stability analysis theory.Finally,the effectiveness of the proposed method is verified by simulation experiments with dead zone and gap nonlinearity.(2)For the multi-agent system under external interference,a multiagent system design method based on separated design is proposed,and the EID estimator and state feedback controller are designed separately.Firstly,an EID estimator is constructed to estimate and compensate external disturbance and nonlinearity by using EID idea.An external consensus control protocol based on EID is designed.The stability and external consensus of multi-agent systems are proved by using small gain theorem and separation theorem.The state observer is designed using the complete Regulation method,and the state feedback controller is designed using Linear Quadratic Regulation(LQR)method.Finally,a multi-motor system is taken as an example,and the effectiveness of the proposed method is verified by simulation experiments under external disturbance and nonlinear conditions.(3)For uncertain multi-agent systems,an external consensus control protocol design method based on sliding mode observer is proposed.Firstly,an EID estimator is constructed to estimate and compensate the uncertainty,external disturbance and actuator nonlinearity as an equivalent input disturbance.In order to suppress the uncertainty,an external consensus control protocol based on sliding mode observer is designed to improve the robustness of multi-agent systems.The stability of the sliding mode observer is proved by Lyapunov function and its design steps are given.LQR method is used to design the gain of state feedback controller,and the steps of parameter design for uncertain multi-agent system are given.Finally,the effectiveness and superiority of the proposed method are verified by the comparison experiment of multi-motor system simulation.