Research On The Controlling Of Networked Control System

A control system is called a networked control system (NCS) if its feedback loop(s) are closed via a shared communication medium. It is a new study field that integrates network, computer, and communication and control technology. In a NCS, the medium's limited capacity must be allocated to all the actuators, sensors, and controllers in the system. The modeling and controlling method of the networked control systems (NCSs) with the medium access constraints and data packet dropout respectively are studied, which preserve the stabilization of system and optimize system performance.Firstly, the conception, some features specific to NCSs in research are introduced. Some basic problems and recent advances in research are discussed in detail. The control method, system model with packet losses, data transferred technology under MAC protocol and switched technique are mostly analyzed.Secondly, we study the controlling method of networked control system under medium access constraints. According to the medium access constraints, a new control method is proposed, namely, a couple communication sequences are adopted to describe the accessing states of sensors and actuators. Combining the plant with communication sequences, the affection of medium access constraints is modeled, and the extended plant of linear-time-varying system is supported. The identifying a pair of limited communication sequences that preserve controllability and observability of continuous-time system is analyzed and then an output feedback controller based on those sequences is designed. Utilizing this control method can reduce the affection of medium access constraints, when the multi-sensors and multi-actuators access the communication medium, and improve the dynamic performance of the control system. Finally, an example simulation is given to validate the method.Then, the controlling method of networked control system with data packet losses is studied. The instance of the packet dropout in NCS is analyzed, which can be treated as the problem of input matrixes of the plant switching and the input matrixes of the controller matrixes switching, then NCS is modeled as a switched system, the problem of data packet dropout is equal to the subsystems of the switched system switching. Based on the model, using Lyapunov method, stabilizability of a NCS is analyzed. Utilizing the solutions of linear matrix inequalities, the parameterize expression method of the state observer and controller is given. Finally, an example simulation is given to validate the method.The end, the research conclusions are presented. The innovative ideas and the remaining problems of networked control systems (NCSs) with medium access constraints and data packet dropout in this thesis need further research.