| As the field bus control technology and Ethernet technique mature, what’s more, their cost performance is keeping improving. Networked control systems have a lot of advantage. Such as less wiring, easy to install and maintain and extend, realize resources sharing and, what is more, arrangement of wire to complicated place by wireless networks. Therefore networked control systems are applied quickly in many domains, such as power, traffic, aerospace, remote control territory and so on. Hence networked control systems has become a very hot topic internationally. Stability is the most important for a networked control system. On the condition of system stability, there will be certain requirements for system dynamic performance. Sampling is one of important parts for a control system and then the research about the influence of sampling on system performance is of great significance. Based on the forefather’s research, a new sampling method, named hyper-sampling, is studied. The thesis is to study the system performance under different sampling method. Some research will be done from the following aspects.First, the optimal design of networked control systems is proposed, including the theoretical research approach introduced and the optimal design under single-sampling and hyper-sampling. When single-sampling and hyper-sampling both are optimal, the influences to a networked control system is simulated by MATLAB. The simulation result show the system dynamic performance under hyper-sampling is better than single-sampling.Second, designing an experimental platform about networked control system is to verify the upper simulation result. The platform consist of MATLAB/Simulink, data acquisition card, the drive circuit and DC motor.Thirdly, the control program of platform is compiled through MATLAB and Simulink Data Acquisition Toolbox. The parameter identification of DC motor, the designing of control block diagram, the hyper-sampling realization by Simulink and DC motor dead-time compensation are included in this part.Finally, the conclusion are the following points. In the case of single-sampling, the networked control system under the optimal period have shorter setting time and smaller maximum overshot. The same condition is the same with the hyper-sampling. When the hyper-sampling and single-sampling are optimal, the result revels that system have shorter setting time and smaller number of oscillation under hyper-sampling. However, it is not always true when the single-sampling is optimal and hyper-sampling is not optimal. |
