Research On Event-Triggered Distributed Communication And Control Method Of Low-Earth Space-Robot Formation System

In recent years,the control of free-flying robot formation system in low-Earth space,as a key technology supporting major national aerospace projects,has attracted extensive attention from many scientific fields.Different from the ground mobile robot formation system,in the complex space environment,the airborne communication,computing and energy resources of low-Earth space robots are extremely limited and can’t be quickly supplemented.However,when multiple robots perform the cooperative maneuver task of formation control,the traditional distributed control mechanism often need frequent signal sampling between adjacent robots and the robot controller needs to be continuously updated,resulting in unnecessary waste.In order to significantly decrease the update frequency of robot controller and the number of sampling communication between robots,based on the advantages of event-triggered mechanism in the rational scheduling of limited resources,this thesis studies a new method of distributed communication and control of leaderless low-Earth space robot formation system through the introduction of event-triggered mechanism,so as to save limited system resources.The main work includes the following:1.The distributed communication and static event-triggered pull-based control method of low-Earth space robot formation system is studied.Aiming at the formation system model of low-Earth space robot,the coupling control method of maneuver guidance control and event-triggered formation pull-based control is designed.Then static triggering conditions are designed through Lyapunov stability theory,so that the robots only need to update the control when the conditions are met.The introduction of pull-based control realizes the independent update time of a single robot controller,further reduces the controller update times of the whole system,and solves the problem that the robots need continuous control update.2.The dynamic event-triggered distributed communication and pull-based control method of low-Earth space robot formation system is studied.Through the introduction of dynamic variables,a dynamic event-triggered formation control method with adjustable minimum inter-event time is designed.Moreover,the design of new triggering conditions no longer depends on continuous neighbor state information,which solves the problem of continuous communication between robots in formation system.3.The complex triggering behavior in the above distributed event-triggered control system is deeply analyzed theoretically.Among them,the comparison principle and the counterfactual method are used to verify that the minimum inter-event time is strictly positive,so as to eliminate the potential possibility of the control system being triggered countless times in a limited time(i.e.Zeno behavior).Finally,the feasibility of the conclusions obtained was proven by MATLAB numerical simulations.