Based On Adaptive Fuzzy Pid Control Design Of The Mirror Dewpoint Meter

An advanced control system is introduced in the article, which is used for a digital Mirror dew point—instrument. According to the flaws of existing control systems and the merits of the same kind of oversea product, a excellent control system for Mirror dew point—instrument is designed.The passage discusses some advanced PID control algorithms, and then choose the control algorithm which suits for the instrument crossponding to each character. To show the intelligence of modern instrument, most of the functions of the instrument are accomplished with software. Replace the functions which accomplished with manpower before of using the SCM. In the process of measurement using Mirror dew point—instrument, the change of gas humidity is very import to the control method of instrument. In the past, the extend of the gas measurement should be setted with manpower, but this table designs two control models crossponding to the character of gas humidity : high-humidity model, low-humidity model. To prevent the vibration when the two models exchange, dew point-instrument designs two model-exchange procedures in terms of Smith Principle, which has satisfied the needs of usage of the instrument with the effect of experiment.Many effective methods are adopted in the hardware circuit and software design, which include multilevel filter with hardware circuit, filter with software, photoelectric Isolation, and modularization design in software. The control accuracy and reliability of the system are improved with these methods.Minor dew point—instrument are used in precise measure of little moisture in gas widely. This paper discuss a design of Mirror dew point—instrument with Fuzzy-PID. This means can improve instrument's measuring precision and avoid error for machine's vibration or change of lamp-house and outside condition.