| In recent years,experts have conducted in-depth research on the field of group collaborative control,and the consensus of multi-agent system has received extensive attention as an important topic in this field.At present,the relevant results have been applied to intelligent vehicle control,pipeline inspection,multi-energy collaborative optimization,UAV formation control and other fields.At the same time,multi-agent system are usually in an open network environment,some malicious intrusions and attacks are difficult to avoid,so it is urgent to study the security of the system.Although experts have studied the secure consensus in sufficient depth,there are still many problems to be solved urgently.At present,most of the researches focus on the complete consensus problem of isomorphic linear MAS with the same dynamics,and there are few theoretical studies on the secure lag consensus problem of heterogeneous nonlinear MAS.In this thesis,the problem of secure lag consensus for three kinds of MAS is studied.Respectively is,the lag consensus problem of heterogeneous MAS with input saturation under actuator attack;the lag consensus problem of nonlinear MAS subjected to DoS attack under certain mapping relationship between leader and followers;the lag consensus problem of second-order nonlinear MAS under DoS attack.Specific research work is as follows :1.This thesis studies the lag consensus problem of heterogeneous MAS with input saturation under actuator attacks.Compared with homogeneous system,heterogeneous system have more complex dynamic characteristics.Firstly,the corresponding lag control protocol is proposed for the heterogeneous system model composed.Then,the error system is constructed according to the designed control protocol,and Lyapunov method is used to verify that control protocol can achieve leader-follower lag consensus.Finally.That is,the control protocol designed in this thesis can ensure the security lag consensus of the heterogeneous system.Finally,the correctness of the proposed theory is further demonstrated by simulation experiments.2.In this thesis,the problem of secure lag consensus for multi-agent system under DoS attack is studied.Firstly,considering that there is a certain mapping relationship between leader and followers,a secure lag control strategy based on error compensation is designed.Then,the upper bound of attack frequency and duration is obtained by using graph theory knowledge and inequality theory.In other words,when the DoS attack frequency and duration exceed the upper bound,MAS will not achieve lag consensus.At the same time,Lyapunov method is used to verify that control protocol can achieve leader-follower lag consensus.Finally,the correctness of the designed control strategy is further demonstrated by simulation experiments.3.This thesis focuses on the time delay phenomenon in the consensus state between the leader and followers,and considers that DoS attack occurs non-periodic.First,a new event-triggered mechanism and lag consensus control strategy are proposed.Then,through Lyapunov method,it is proved that followers and leader can achieve lag consensus under DoS attack,and the upper bound of attack frequency and length rate is obtained.The trigger interval is designed to ensure that Zeno behavior does not occur.Finally,the correctness of the designed control strategy is further demonstrated by simulation experiments. |
