Ethernet And Fieldbus-based Process Control System Experimental Setup

In order to make the college students receive excellent project training, it is an important goal for the automated lab to construct a laboratory with real engineering environment. According to the characteristics of the automation major and the correlated majors, by means of the two-layer network topology, the process control system used in experimental facility has been exploited based on the industrial ethernet and fieldbus.The experimental facility adopts many technologies such as PLC, network, computer monitoring, and the process control instrument which is usual used by the industrial field. The principle controlled variables of the system include liquid level, pressure, temperature and flow. The upper layer introduces the ethernet, and the lower layer is Profibus-DP. The controller is S7-300/400 PLC of Siemens. The softwares such as STEP7 V5.1, WinCC V5.1 and SIMATIC NET V5.3 is used to design the experimental instruction software. The function of this software includes state monitoring, data collecting and communicating, data recording and dealing, digital PID control and intelligence control algorithms.Aiming to this facility's the feature, take example for the liquid level control system in this paper, its mathematical model is builded and the unknown parameters in its transfer function can be obtained by the method of the parameter identification. The paper also depicts the dead-section and integral splitting PID algorithm's application in the liquid level control system. Based on this application, the BP neural network PID control algorithm is proposed, and an experimental platform of the neural network is exploited. In this platform, making use of the neural network, PID's control parameters can be trained.The device can be used in many fields such as teaching, studying and researching. The students can do not only the traditional or modern automatic control experiments, but also realize emulator experiment ofmanifold advanced control algorithm with the collected data by employing many advanced algorithms. Moreover, through this entire automatic control experiments, students may obtain full training like production process control system constituting, designing and running, the experimental facility also offers an researching & exploring platform for the teachers and the graduates.