The Study Of Optical Fiber Fluorescence Thermometry System Based On Fuzzy Strategy

The thermometry technology with optical fiber fluorescence has lots of advantages,like high pressure resistance,better corrosion resistance together with strong security performance,so it can make up for certain shortcomings of traditional thermometry methods in high voltage,strong electromagnetic radiation,flammable and combustible circumstance.Therefore,it can be applied in multiple areas,such as electric system,construction industry,petrochemical industry,medical treatment and so on.In recent years,scholars and enterprises have been concerning about the development of fluorescence thermometry technology.In this paper,a new type of optical fiber fluorescence thermometry system based on fuzzy strategy is designed,which has excellent detection accuracy,so it can be used to a much wider area.Firstly,three stages of fluorescence generation are analyzed in detail in this paper.Based on principles of fluorescence generation,afterglow decay expression is obtained,and then the information of fluorescence lifetime is concluded.So we can summarize the principle of optical fiber fluorescence temperature measurement,which supplies theoretical evidence for system.At the same time,the non-exponential cause of sampling afterglow curve in practical application is proposed,and the paper summarizes the reasons from light emitting mechanism and hardware circuit.Secondly,this paper studies and designs the temperature measurement system from four aspects:the sensor system scheme selection,light path and circuit design,data processing algorithms.In sensing system part,the features of components are analyzed,such as fluorescent materials.active light source.photoelectric converter device,fiber-optical,etc.Then the rare earth phosphor is selected as system temperature material,the ultraviolet light emitting diode is used as excitation source,the silicon photodiode is used in photoelectric detection section,and the fiber core diameter is 400?m.In optical path part,the design of sensor probe,optical signal coupling and propagation route are accomplished.The light path volume is small and easy to achieve.In circuit part,the light source excitation circuit,photoelectric conversion and amplifying circuit and MCU designs are realized.In data processing algorithm part,the principle and simulation analysis of several fluorescence lifetime algorithms are firstly carried out,and then considered the accuracy?processing speed?stability and difficulty degree of algorithm,integral method is finally selected.In order to eliminate the non-exponential influence of afterglow curve,fuzzy strategy is applied in thermometry system to achieve the compensation for fluorescence lifetime.Build the model of fluorescence temperature measurement system by matlab software to verify the design of fuzzy structure,and use it to realize data processing of thermometry system.Finally,the experimental platform is built to test the thermometry system.The optical fiber fluorescence thermometry system can achieve the temperature measurement within 0?200?,the accuracy is within plus or minus 1?,and it has good temperature measurement performance and engineering practical value.