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The Design Of Networked Control Systems Based On Stochastic Switching

Posted on:2018-08-25Degree:MasterType:Thesis
Country:ChinaCandidate:L H YangFull Text:PDF
GTID:2348330566950064Subject:Control theory and control engineering
Abstract/Summary:PDF Full Text Request
The closed-loop feedback control systems where the plant, sensor, controller and actuator are connected through communication network with limited bandwidth are called networked control systems (NCSs). This kind of networked control mode has many advantages, such as resource sharing, easy extension, easy maintenance,high efficiency, high reliability, low cost and high flexibility and so on. Recently,NCSs have been drawing more and more attention from researchers working in the areas of system and control. However, the insertion of a communication network results in some challenging issues on account of the limited network bandwidth,such as network-induced delays and packet dropouts, which may lead to performance degradation or even instability of networked control systems. Therefore, aiming at these problems in the networked control systems, the corresponding system model is established and the design methods of reliability control and filter of the system are studied. In this paper, the main work is as follows:Firstly, some random variables which meet Bernoulli distribution are introduced. Considering the problems of uncertainties and time-varying delay in the system, the system is modeled as a more general networked stochastic switched system. Sufficient conditions for the robust mean square stability and stabilization of the networked stochastic switched system are studied by Lyapunov stability theory and LMI technology. The less conservative results are obtained by using Wirtinger integral equality, based on which the robust H? controller is designed, which make the system has better dynamic performance.Secondly, considering the stochastic distortion of multi-channel actuators, a novel stochastic actuator distortion model is established. Based on the event-triggered communication mechanism, a more general model of networked control system with multiple actuator distortions is obtained. Sufficient conditions for the mean square stability of the system under the condition of actuator distortion and time-varying delay and the design method of reliability H? controller are obtained by Lyapunov stability theorem and LMI technology. Then the effectiveness of the proposed method is verified by simulation examples.Thirdly, considering the existence of network delay and sensor stochastic distortions in the networked control systems, the problem of event-triggered reliable H? filtering for networked systems with multiple sensor distortions is investigated.The interval of sensor distortion in each channel is partitioned several segments. By introducing a set of random variables, the model of multiple sensor distortions with their information of Bernoulli probability distribution in each segment is established and a novel filtering error dynamic system is achieved. Based on the above analysis,the design method of event-triggered parameter and filter parameters is obtained.Finally, a new adaptive event-triggered communication mechanism is designed in the networked stochastic switched systems and based on the above the filter design problem is investigated. The event-triggered scheme of dynamic adjustable threshold is constructed and the adaptive event-triggered condition is given and the filtering error system model is built. Then, the filtering error system is analyzed by Lyapunov functional method and LMI method and the co-design method of filter parameters and adaptive event-triggered matrix is achieved.In the end of this paper, the full text is summarized, the existing problems in analysis and design of the networked control systems are pointed out, the prospect of the future research and development direction of the networked control systems are put forward.
Keywords/Search Tags:Networked control systems, Stochastic switching, Event-triggered scheme, Robust H_? control, H_? filtering
PDF Full Text Request
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