Design Of Temperature Controller Of Synthetic Quartz Production Based On The Gray Predictive Fuzzy Theory

Recently, high-quality piezoelectric quartz gets the favor of market due to the highly development of communication technology, which need new and higher requirements to synthetic quartz technology and control equipment. The Production process of synthetic quartz has always been carried out under high temperature and pressure, in the process, the temperature curve directly determines the quality of crystals, that is the high and low of the crystal quality factor (Q value).Based on the development of temperature control technology of synthetic quartz production process at home and abroad, the paper makes a further study on the complex temperature controller of synthetic quartz production, which nonlinear, big lag time, big inertia by combining the predictive control and fuzzy control together, and realize it by utilizing actual analog and embedded technology. The dissertation has completed the following aspects:First of all, based on the controller working condition of the synthetic quartz production, we designed the temperature controller with a core of C8051F from Silicon Laboratories which greatly simplified the hardware circuit of system. As well as the specific requirements of the temperature sampling, designed the acquisition and transmission modules of temperature sampling. Select the K-type thermocouple as temperature sensor, designed temperature-current transmitter around the transmission chip XTR105. Solve the voltage signal loss in long-distance transmission through converted voltage signal to current signal. The thermocouple cold junction automatic compensation is realized by integrated temperature sensor AD590. Between controller and host computer using RS-485 communication interface to achieve reliable long-distance communication. At the same time, the details of reliability of the hardware design are simply described.And provides an overview of the gray prediction control method and fuzzy control method, analyze the necessity and importance of combining predictive control and fuzzy control, introduce the details of gray model and fuzzy control knowledge. And make research and analysis simulation based on gray prediction fuzzy control, the method has been applied to nonlinear, big lag time, big inertia of the complex synthetic quartz production systems. The simulation results show that gray prediction fuzzy control have stronger anti-interference ability than PID control, compared with traditional PID control, the fuzzy predictive control have higher accuracy and smaller fluctuations, the effect of control have obvious improvement, it is applicable to nonlinear, big lag time, big inertia control system such as the temperature controller of synthetic quartz production.Finally, aimed at actual needs of temperature controller in practical production, we designed software framework of the control system. The software design is adopted by modularization, the software function is clear and easy to modify and adjust, and it is very convenient to system software upgrade and adds new function.