On Stability For A Class Of Uncertain Networked Control Systems With Time Delay

Networked control system (NCS) is the collection communication network and control system in one of the more complicated control system. It has many advantages, such as resource sharing, less connection, easier expansion and maintenance, high efficiency, reliability and flexibility, etc. However, because of introducing the network into traditional control system and the limits of the network bend, so that it is inevitable that there exits the networked-induced delay, message collision, time sequence confusion and data packet dropout etc. They degrade the performance of control systems. Therefore, a research is needed in networked control systems.In this thesis, the system is to be controlled as a class of networked control system with time-varying delay and parameter uncertainties, some factors are ingeniously taken into account appropriately, such as the network-induced delay, packets loss and out-of-order packets, as well as external interference, making the model of more system close to reality. Based on the built control model, we discuss several common control problems, in which we use Lyapunov stability theory, linear matrix inequalities approach, formula of Newton-Leibniz and free weighting matrices method to get the sufficient condition of system meeting the asymptotical stability and guaranteed a certain performance index, and based on this, we attain the corresponding designing method for control law with less conservation. This article discusses the following major elements:1. The robust control of the uncertain networked control system with time delay:Based on the establishment of the system's model, making use of Lyapunov stability theory and linear matrix inequality (LMI) approach to prove a sufficient condition for the robust stability, while a robust stable control law design method was given.2. The robust guaranteed control of the uncertain networked control system with time delay:On the premise of the system satisfying the asymptotic stability, based on the performance index proposed by the system model, by choosing a suitable Lyapunov function, via Lyapunov stability theory and the linear matrix inequality(LMI) approach, we get a guaranteed cost control law.3. The robust H? control of the uncertain networked control system with time delay:For the presence of external disturbances with finite energy on the basis of the existing model, fist we add the external disturbances with finite energy to the existed model and then we get the new system model, second by the Lyapunov stability theory and the linear matrix inequality(LMI) approach proving the sufficient condition that the new system satisfies the robust stability, and then we obtain the way to design the robust H? controller.