Model-based Networked Control System Research

A class of networked control systems (NCS) where in the control loops are closed through communication networks. This family of systems is an integration of plants, sensors, controllers, actuators and communication networks of certain local field. Networked control systems have advantages of less wires, high reliability, increased system agility, good flexibility and share of information resources, etc. But networked control systems have their own drawbacks, too. The medium of control network is time sharing multiplexing, so the messages can not be transmitted until the network medium is free. Given the point above, the network induced time delay is introduced into the networked control systems inevitably. Depending on the network protocol the characteristics of time delay could be constant or time-varying, which makes it hard to analyze and design networked control systems.In this report the control of continuous linear plants where the state sensor is connected to a linear controller/actuator via a network is addressed. Specifically, the controller uses an explicit model of the plant that approximates the plant dynamics and makes possible stabilization of the plant even under slow network conditions. Necessary and sufficient conditions for stability are derived for the presented setup in terms of the update time and the parameters of the plant and of its model. The deterioration of behavior when either the update time or the modeling error increase is explicitly shown.Model-based network control systems' working characterizations are investigated in this paper where the plant to control is in a form of singular system. A simulate model is added between the sensor and the controller, which is as a character of model-based network control systems. The error information, emerging when the control plant passed from the network, including the state of the control plant, is used to simulate the state vectors of the original control plant. Then a mathematic model of the model-based network control system with a singular system formulation is constructed. The stability is studied when the network transmit time-delay is smaller than a constant of a period of sampling time. At last a numerical example is given to show the efficiency of the approach and theory proposed in this paper.In this report we will concentrate on characterizing the transfer time between the sensor and the actuator. The transfer time is the time between information exchanges from the sensor...