Research On Sliding Mode Control Strategy Of NPC System Under Communication Constraints

With the development of communication technology,the application of net-work information has penetrated into all aspects of social life,such as robots,aerospace and industrial production.At the beginning of the 21st century,net-worked control system based on communication network appeared in control the-ory.Networked control system(NCS)refers to a control system that exchanges data through the closed-loop system in the communication network,which is based on computer technology,information technology,control technology,net-work technology and communication technology.NCS is a completely distributed feedback networked system,including controller,sensor,actuator and communi-cation network.Compared with the traditional point-to-point control systems,NCSs have many valuable features,such as shared resources,remote operation,reduced system cost and power consumption,as well as simple system installation and maintenance.NCS has been proverbially used in many commercial fields,such as modern transportation in complex control system based on communication network,the advanced control of complex industrial process,vehicle group of coordinated con-trol,smart home,etc.Nevertheless,due to the introduction of communication network,the analysis and design of the system becomes more complicated,and there are new problems in networked control system,such as networked commu-nication limitations,data loss,network-induced delay,and multi-packet simul-taneous transmission.Network-induced delay and data loss are two dominating factors that affect system performance.Many schemes have been presented to ad-dress this problem,among which networked predictive control is the most popular method to actively compensate for delays.Thanks to the growth of computer technology,electronic technology and multi-agent technology,the measurement accuracy and data calculation speed have been improved.On the other hand,it brings great challenges to data trans-mission and storage.In order to reduce the number of data transmission,an event-triggered control(ETC)scheme is proposed.Different from time-triggered control,it can effectively reduce unnecessary data packet transmission and data calculation,and reduce energy consumption and storage pressure.Since event-triggered control has important theoretical and practical significance,more and more researchers have proposed and studied various trigger schemes in recent years.Sliding mode control(SMC)is a very effective robust control strategy,which can deal with the uncertain factors such as external disturbance and parameter perturbation.SMC has the advantages of easy physical implementation and fast response and has been applied to many aspects,such as intelligent robots,power system networks and aircraft.In this work,we propose an event-triggered sliding mode control based on networked control system,which solves the problems of data transmission delay and external disturbance in the network.In addition,the event-triggered control scheme reduces the amount of data transmission and saves the network bandwidth resources.