Composite Nonlinear Feedback Control Of Saturated Systems With Event-triggered Strategy

Actuator saturation is a nonlinear phenomenon and will affect the stability of the system.The dead zone function method can be used to handle it.The composite nonlin-ear feedback?CNF?controller is composed of linear controller and nonlinear controller,which can improve the response speed and weaken the overshoot of the system,while ensuring the tracking of the reference input.In addition,the event-triggered strategy can sample the system signals intermittently according to the designed triggering con-ditions.That is to say,when the triggering condition is satisfied,the event-triggered mechanism will sample and transmit the sampling signal.Otherwise,the sampling sig-nal will keep the value of the latest transmission sampling.It should be noted that the event-triggered mechanism can save the communication resources on the premise of en-suring the stability of the system.The fewer triggering times,the more communication resources will be saved.However,the system may be unstable with the decrease of the number of triggering.Therefore,the triggering number cannot be produced indefinitely.In this thesis,the CNF state controller,the observer based CNF controller and the CNF robust controller are designed for the saturated system with event-triggered mech-anism.In addition,the static and dynamic event-triggered mechanisms are respectively adopted,and the design of event-triggered conditions contain the parameters of CNF controller.By doing so,the event-triggered mechanism and the CNF controller can be well combined.The main design idea of the tracking performance of the system is as follows:First,the stability criteria can make the system asymptotically stable and track the reference input signal,which is constructed by using Lyapunov stability theory,sector condition,the invariant principle and so on.The parameters of CNF and event-triggered mechanism can be designed according to these criteria.Then the minimum triggering interval is calculated so as to avoid Zeno phenomenon effectively.Moreover,consider-ing the existence of disturbance,the L₂-gain of the closed-loop system is obtained by H_?control.