Event-based Tracking Control Of Nonholonomic Mobile Robots

With the wide application of network control,the problem that how to overcome the limitation of limited channel bandwidth has attracted more and more scholars to study.Some scholars propose event trigger control by reducing the frequency of network use.In event trigger control,the trigger is only carried out when the error exceeds a certain threshold,making the system close loop and updating control.However,the traditional periodic control has a small settled sampling period and it keeps sampling and updating even when the system itself remains stable,which is a waste of communication resources.Therefore,event trigger control can reduce the consumption of communication resources compared with cycle control.After several years of development,new event triggering mechanisms have been proposed,and the applicable systems have changed from linear systems to nonlinear systems.However,on the one hand,there is no research on time-varying nonlinear systems;on the other hand,the current event triggering mechanism relies heavily on ISS's Lyapunov function.In this paper,different kinds of event triggering mechanisms are established for the trajectory tracking control system of the non-holistically wheeled mobile robot,a time-varying nonlinear system,without using the Lyapunov function of ISS.In this paper,a trajectory tracking control law is proposed and its exponential stability is proved.For a quadratic Lyapunov function,the Lyapunov function is semidefinite under the control law.Therefore,in the case of event triggering,the Lyapunov function is not the Lyapunov function about the error ISS.However,based on this Lyapunov function,static event triggering mechanism,dynamic event triggering mechanism and event triggering mechanism based on Lyapunov function are established respectively in this paper.The tracking error is finally bounded uniformly and the Zeno phenomenon does not exist in the system.Finally,a self-triggering mechanism is established to further reduce the sampling frequency in the system.All the conclusions are proved in detail and the validity of event triggering mechanism is verified by simulation.The results show that the event triggering mechanism designed in this paper can greatly reduce the occupation of communication resources and save energy while ensuring the control effect.