Networked Control Systems Fault Detection Based On Event-Triggered Mechanism

After the third industrial revolution,industrial systems began to shift from centralized control to decentralized enhanced control,with its scale becoming increasingly larger and structure more complex.With the rapid development of technologies such as the Internet and the Internet of Things,the era of Industry 4.0 is coming,and industrial systems are gradually accessing cyberspace.Networked control systems refer to the connection of various components(sensors,actuators,etc.)of a system through a shared network.It has the advantages of strong anti-interference ability,good stability and low cost.Due to the limitation of network communication resources in the actual system,however,there are delays and packet loss in the transmission of data,which brings lots of problems to the analysis and design of the control systems.As a result,the fault detection of networked control systems has great practical value and deserves in-depth study.Data loss in networked control systems and the fault detection method under communication constraints are studied in this paper.The main contents are as follows:First,this paper studies a fault detection filter design method for a linearized network system having communication resource limiting characteristics.Considering the event trigger mechanism design can reduce the amount of data transmitted in the network and save communication resources,this paper applies the design idea to the fault detection of networked systems.The networked system fault detection filter based on event trigger mechanism is designed to realize the fault detection of the system.Among them,the H_?optimization performance method is used through the influence of minimized fault detection model on external disturbances and faults to realize the target of network system fault detection.According to the Lyapunov stability theory,the sufficient conditions for the stability of the model are derived.An LMI-based solution method is used to solve the parameter matrix of the filter.Secondly,the fault detection filter design methods of networked system with communication resource limitation characteristics and random packet loss of network data are studied.For the random loss of data in the network,it is assumed that it conforms to the Bernoulli distribution,and the phenomenon is simulated by the Bernoulli white noise sequence.Based on the research of the design method of linearized network system fault detection filter with only communication resource limitation characteristics,the fault detection filter model which can deal with the random packet loss phenomenon of data is designed.Based on the Lyapunov stability theory,the sufficient conditions for the asymptotic stability of the model and its expected detection index are given,and subsequently the method for solving the parameter matrix of the fault detection filter of the networked system is derived.Finally,a combined design method between fault detection filter and controller of the uncertain networked control systems with communication resources limitation characteristics is studied,which realizes the control of the system and has the fault detection capability.In this controller design,a filter and an output feedback controller are integrated.The controller can ultimately achieve the expected control indicators and fault detection indicators while achieving progressive stability.There are two independent event triggers in the controller design to reduce the amount of data in the network channel between the controller and the sensor and between the controller and the original system,which effectively reduces the amount of data transmitted and saves the communication resources.Through optimizing the algorithm,the controller and the parameters of the two event triggers are solved by multi-objective optimization,taking into account the uncertain model and the data transmission scheme based on the event trigger mechanism.