Sliding Mode Control Design Under Event-triggered Strategy And Its Application

Many real-world systems and processes contain uncertainties and external disturbances,which may lead to the instability of the system and are hard to analyze and synthesize.Thus,it is significant to find a control strategy capable of handling these factors.Moreover,sliding mode control,for its fast response,simple design process and strong robustness for the parameter uncertainties and disturbances,has become a concern of the robust control method.At present,the sliding mode control has been successfully applied in many practical fields.Additionally,with the rapid development of computer technology,the research on discrete-time system has become popular.Therefore,it's significant to study sliding mode control for discrete-time systems.On the other hand,with the rapid development of computer communication,network technology and information processing technology,network control systems have been made some significant progress.However,due to the limited network communication bandwidth and network resources,these factors should be fully considered in control strategy design.Thus,the event-triggered strategy becomes the focus of attention of many scholars since it can significantly reduce the transmission of data in the network,save network resources and energy consumption.Noting that,although there have been a lot of results on sliding mode control methods and event-triggered strategies,there are almost no researches on the combination of the two methods,researches on this field are significant and challenging,and the conclusion is very useful for researchers in this field.In this thesis,we focus on the problem of sliding mode control under event-triggered strategy.By combining with the event-triggered strategy,it can not only optimize the defects of the single sliding mode control in the control of systems,but also save the network bandwidth.The research contents of this paper are as follows:(1)Based on the traditional sliding mode controller design method,a new sliding mode control method for discrete repeated scalar nonlinear switched systems is presented.By using the average dwell time method and the positive diagonally dominant Lyapunov function approach,it is proved that the design method proposed in this thesis can ensure the stability of the control system with satisfactory performance index.(2)Based on the properties of the event-triggered strategy,a sliding mode control design method based on event-triggered strategy is proposed for discrete switched system.By using the Lyapunov stability theory,it is proved that the designed sliding mode controller in this thesis can ensure the trajectories of the controlled system to reach the sliding mode surface in finite time.(3)Based on the research results of event-triggered-based sliding mode control strategy above,we apply this method to solve the load frequency control problem of multi-area power system.The simulation results show that the proposed sliding mode control algorithm based on event-triggered strategy is superior to the general sliding mode control method in load frequency control of multi-area power system,that is,the system stable can be guaranteed,and the network bandwidth is successfully saved.