| With the rapid development of modern network technology, the network already becomes an important component in modern society, and its application has already spread to people’s daily life. Introducing the network to traditional control system can greatly improve the modularity of control system, which will strengthen its anti-interference ability and flexibility, and can reduce the cost of control system wiring, the installment and the maintenance. But adding the network into the NCS has also brought a series of new questions, like delay and packet dropout and so on. In order to reduce the network-induced delay and the packet-drop rate, this article conducts the deep research on the network control system two main matters, and proposes to establish an advanced PID controller including the fuzzy control which is an intelligent control.Firstly, this article introduces a very important simulation software in great detail which is TrueTime developed by Department of Automatic Control, Lund University of Sweden, which is utilized widely in NCS field. And using in this tool to study the specific impact of nodes delay which are controller, actuator, sensor, and so on, and also has conducted the analysis of how to select network protocol in the case of the different controlled plant, and confirmed the deduction through the concrete experiment.Then, this article has designed the PID controller and the fuzzy controller with emphasis. As the commonly used controller in the modern industry production process, the PID controller’s application is very widespread and universal. However, owing to some inherent flaws included by in PID controller itself, PID controller appears helpless when it meets the complex controlled plant whose load is changeable, but it will be helpful to improve the stability performance of the system by introducing Fuzzy Control. Design the PID controller and the fuzzy PID controller by using MATLAB/Simulink and Fuzzy toolbox.Finally, establish the NCS simulation model, and carry on the concrete experiment simulation. Carry on the NCS simulation based on fuzzy PID controller through establishing the MATLAB/Simulink simulation model of NCS, and compiling the code used by each module the correspondence and the controller. The simulation has compared the fuzzy PID controller’s and PID controller’s performance under the same level condition, the results show something that the fuzzy PID controller can get smaller overshoot, the shorter response time, the steadier system response. |
