The Application Of Fuzzy Control And PID Control On Coating Production Process

Temperature is one of the main objects of industry control. In industry process, we often need to control the temperature. Excellent control over temperature can not only enhance the quality of products, but also reduce energy consume and enhance efficiency. PID control method is used in temperature control the most comprehensively. It is very simple and has good stability as well as dependability, so it is often used in those linear constant system. But it cann't bring us perfect control effect when it is used in nonlinear systems, one of which is hysteresis system, such as temperature control system.Intelligent control independent of model of a plant and based on knowledge offers a new idea for improving the industry control quality, of which Fuzzy control is the most active and fruitful field. Fuzzy-PID control is one of the main techniques in research and application due to the dominant place of PID types control in industrial process control recently. If the controller which has better performance and is wieldy like PID can be found, there will be significance in both theory and practice.To control arithmetic, a method of combining the theory of the fuzzy and PID control is advanced in this paper. By studying and researching the basic theory and method of the fuzzy control and PID control in both home and abroad, the writer analyzes the advantage and disadvantage in temperature control of numeric PID control system and several complex Fuzzy control systems. According to the working performance and the temperature characteristics of the coating line's reactor, a kind of P-FUZZY-PID controller is devised and is applied in Rosemount control system, which is simulated by MATLAB software.The P-Fuzzy-PID controller that have been described in this article combines the proportional controller, fuzzy controller and PID controller, which adjust the system quickly by proportional control system and make the system have the agility and adjustability characteristics owing to the fuzzy control system and run stably resulting from the PID control system. According to coating line's temperature control system that has the characteristics of nonlinear, time-variable, time-delay and so on, the fuzzy controller which can works immediately and stably will conquer its characteristics of nonlinear, time-variable, time-delay;the PID controller which can run precisely and acutely will make the system possess of good steady characteristic.The fuzzy-PID controller will make what you want come truth. The trend come from experiment tell us many things, such as it removes the integral saturation, it settles the contradiction between high speed and over-adjustment, it gives strong applicabillity to the control system, it results small or no infection among the three parameters and causes them easy to choose. In conclusion, the Fuzzy-PID controller will bring the good characteristics of lu-bang, stability, hi-speedy, acuity, and improves the anti-jamming ability and tracking capacity of the control system.