The Research Of Thermal Control System Based On Fieldbus And The Development Of Its Configurable Program

Nowadays, as the development of information technology, the traditional way of monitor and control has been influenced deeply. Fieldbus technology is becoming more and more popular because of its simpleness in structure and easiness in maintain and high reliability and openness. Control system based on Fieldbus has caused an epoch-making change in industry control realm. The automation of thermal control system has always been a hot point in industry control realm. This paper introduces the basic structure and realization of thermal control system based on PROFIBUS.Conventional PID-type controllers have played a dominant role in the heat exchanger systems due to its simple control structure and ease of design. However, PID-type controllers may encounter problems such as large overshoot and even poor stability in the control of plants with time delay.In recent years, plenty of advanced control techniques have been developed. Fuzzy Logic Control is one of these new paradigms and has become very attractive in industrial practices. Because of its capability to emulate human thinking and human inference and to capture the inexact information of the plant, Fuzzy Logic Controller (FLC) often yields satisfactory performances.This paper designs the control system of a cross-flow air/water heat exchanger, in order to indicate the use of Fuzzy Logic Control in thermal control realm. In the water outlet temperature control, this paper uses Matlab to simulate the PID control, Fuzzy control, and also the Fuzzy-PID two-mode control. Simulation results illustrate that the Fuzzy Controller is effective in suppressing the maximum overshoot and in reducing the decaying oscillation cycles.In order to realize the control arithmetic, this paper uses the PLC, and designs the programs of both PID control and Fuzzy control.In the end, this paper uses the configurable software Kingview to configure the whole control system. The software can achieve data collection inside, real-time data and history data can be displayed, real-time curve and history curve can be pictured, real-time modify the controlled parameter, by the follow up to achieve real-time monitor and control of the system.