Research On High Precision Temperature Control System Based On Fuzzy PID Control

This paper mainly studies the design and application in temperature control of self-tuning fuzzy PID controller.Temperature is one of the important parameters in industrial production and scientific experiments,due to the time-varying,time-delay and non-linearity of temperature control,the traditional PID controllers are difficult to achieve ideal results.To obtain better control performance,it is necessary to continuously adjust the parameters of PID controller according to the status of the controlled object.Aiming at solving these problems,the design ideology and hardware realization of self-tuning fuzzy PID controller used in the temperature control,are presented in this paper.Firstly,the paper introduced the principle of PID controller and studied the digital PID algorithm.By combining fuzzy control and digital PID control,self-tuning fuzzy PID controller algorithm and detailed design was proposed.In the end,the detailed hardware design of self-tuning fuzzy PID controller was provided and it was used in the temperature control of Rb vapor cell,verifying the good effect of self-tuning fuzzy PID controller.In this paper,the STM32F103VCT6 microprocessor produced by ST-Microelectronics was selected.The hardware circuit was composed of temperature measure circuit,signal generation circuit,power amplifier circuit,temperature control circuit and communication circuit,etc.T typethermocouple,LT1025 and OP27 were used to achieve conditioning and amplification of the temperature signal.In order to save costs,the direct digital frequency synthesizer was constructed using the Timer,DMA and DAC of STM32 to realize the signal generation function.The power amplifier circuit amplified the generated signal,which was used to heat the Rb vapor cell.The control circuit used fuzzy PID control algorithm to continuously adjust the amplitude of the output signal so as to achieve the purpose of controlling the temperature of the Rb vapor cell.The serial communication circuit was mainly used for setting and displaying the temperature,and communicating with the computer,so that a good man-machine interface and better monitoring of controlled object could be realized.