Studyof Wireless Hybrid Networked Impulsive Control Systems And Application

At present,the control strategies in networked control systems(NCSs) are most ceaseless, such as that the whole control process uses network to communicate signals. This leads to control strategies are vulnerable of the network's performance and it is useless to reduce the network communication and congestion. At the same time, with the development of wireless technology, NCSs are coming into the wired/wireless hybrid network era. So it is necessary to study the control strategy which relying on the network performance less and NCSs based on wired/wireless hybrid network.This thesis studied NCSs via wired/wireless hybrid network and impulsive control strategy which has discontinuous control character. The main contribution is summarized as follows:1. The model of networked control systems based on impulsive control is presented and the exponential stability of networked control systems with constant delay is studied. Firstly, impulsive control strategy which can change the state value in some time point is introduced; Then, the model of networked impulsive control systems is provided which use clock switch produce impulsive signal and lastly, by employing the method of Lyapunov functional, an exponential stability criteria is established in which derivative of Lyapunov function can be positive.2. The exponential stability of multiple communication channels NCSs with bounded and random time delays is studied. Stability conditions doesn't require network delay less than impulse interval which reducing the conservatism of the theorem. Firstly, the model of NCSs is presented which considered network induced delay is bigger and smaller than the impulsive interval. By employing the Razumikhin technique and Lyapunov functions, an exponential stability criteria and the relation between convergence rate and controller's parameters are presented. At the same time, the shortage of impulsive control is also discussed. Simulation results illustrate that the proposed method has better control effect and is suitable for the environment with low channel bandwidth or large noise interference.3. The time delay character of industrial network based on IEEE802.15.4a is studied and the preliminary mathematical model based on test data is also presented, which changing the network time delay situation of hypotheses. Several sets of practical experiments are conducted to study its various features, including the effects of numeral wireless nodes, data transmissions with different upper-layer protocols, physical distance between nodes, adding and reducing the number of the wireless nodes. The mathematical model between network induced delay and network nodes is set up and some issues that could degrade the network performance are discussed.4. The hybrid wired/wireless network is constructed and its time delay character is studied based on theoretical analysis and test data. The relationship and differences between wireless network and hybrid network are presented too. Firstly, theoretical analysis of hybrid network's real time character is given by analysing the structure and protocol conversation technology of hybrid network. Then, method to test the time delay character of hybrid wired/wireless network is proposed. Finally, the character of hybrid network is presented from the test result which also illustrating the theoretical analysis's correctness.5. An evaluation methodology of network performance is presented and its corresponding software is developed. According to the various network performance index and lack of unified method of network evaluation, a comprehensive evaluation method based on objective and subjective evaluation is established. By applying to evaluate the lab's hybrid network and simulation network, the method is illustrated to be effective. A network evaluation software is also developed by modular programming which giving a reference to the network designer.6.Experiment of NCSs based on wireless hybrid network is studied, which containing the measurement platform of power generation system and semi-physical simulation of impulsive control strategy based on time delay character of hybrid network. Firstly, Wireless hybrid network is applied to Rankine cycle system. The results show that the hybrid network can realize measurement function. Secondly, semi-physical simulation of networked impulsive control systems is studied based on hybrid network's performance. It provides the foundation of experimental and application for NCSs based on impulsive control.