Research On Security Control Of Networked System Based On Sliding Mode

With the development of network technology and control theory,the application of networked control systems(NCSs)in industry has become increasingly widespread.However,with the complexity of networked control systems and the involvement of communication networks,new problems have been introduced in its work,such as multi-channel transmission,network interference,network communication protocols,and network security.These problems will affect the effective stability of networked system control.In response to the above problems,this paper is based on the sliding mode control algorithm(Sliding Mode Control,SMC)combined with advanced theory,through the design of observers and controllers to track the speed of the networked control system(take the DC motor platform as an example),and through digital simulation Verification with the experimental plant.The main research content of this article is divided into the following three parts:Aiming at the shortcomings of the speed tracking control of the DC motor system with multiple channels and external interference in the existing networked remote-control system,a second-order super twisting sliding mode control(Second-order Super Twisting Sliding Mode Control,SSTSMC)method.First,analyze and model a DC motor system with multiple channels and external interference.For the selection rules of multiple channels,the Stochastic selection is carried out according to Stochastic Communication Protocol(SCP).Then the super twisting observer(STO)is designed according to the super twisting algorithm(STA),which is used to estimate the system state.On this basis,a second-order super spiral sliding mode control algorithm based on the super spiral observer is designed to track the speed of the DC motor.In the design of the controller control items,nonlinear items are constructed to suppress external interference and jitter when switching between channels.And the effectiveness of the control method is proved by analysis;finally,simulation and experiment prove that the method has better control effect than the traditional sliding mold.Aiming at the speed tracking control problem of multi-sensor servo system with external interference and denial of service(Denial of Service,DoS)attacks in networked control,first analyze and model it,and then propose a sliding mode algorithm based on the observer is used to observe and estimate external interference.Secondly,in order to select data from multiple sensors in network transmission for transmission,a weight-based one discard(Try Once Discard,TOD)protocol is used for analysis,and the largest error item is selected for priority transmission and update through analysis.Then,the DoS attack problem in network control is analyzed,the sliding mode control algorithm based on approach rate is designed through the observer,and analyze the effectiveness of the control method from the finite time convergence of sliding mode motion;finally,the effectiveness of the method is demonstrated through simulation and experimental verification on the physical platform.Aiming at the speed tracking control for networked control systems with external interference and false data injection(FDI)attacks in networked control,firstly,it is modeled and analyzed,and then an extended state observer(Discrete-time Sliding Mode and Neutral Network Extended State Observer,DSMNNESO)based on discrete sliding mode function and neural network is proposed to observe the extended state and suppress external interference and the impact of FDI attacks.On this basis,a new hybrid discrete sliding mode control(Hybrid Discrete-time Sliding Mode Control,HDSMC)strategy combining discrete terminal sliding mode control and super spiral algorithm is designed.Suppress the jitter problem,and prove the convergence and reachability of the sliding motion.Finally,simulations and experiments prove the effectiveness and feasibility of the proposed method.