Research And Design Of Temperature Monitoring System Based On Bragg Grating

The change of temperature can reflect the change of the operation status and many physical characteristics of modern industrial equipment.The measurement of temperature quickly and effectively and the real-time and effective control become an important subject of scientific research and production practice.Due to the high-voltage devices in the power system,petrochemical flammable and explosive hazardous areas,long distance transmission of traffic signals and other fields using traditional temperature sensors cannot be achieved real-time temperature monitoring.Fiber Bragg Grating has the important meaning of replacing the traditional temperature sensor for the temperature monitoring in the industrial environment of special environment with its unique advantages of strong anti-electromagnetic interference,good electrical insulation,high sensitivity and long-distance transmission.Optical fiber sensing technology is a new technology,which has been expanding rapidly along with the emergence of optical fiber and the development of optical fiber communication technology.Based on the theoretical analysis of fiber grating sensing technology and fiber Bragg grating temperature measurement,combined with the current research status of fiber Bragg grating sensing technology at home and abroad and its common fiber grating demodulation technology,this paper designed a Bragg grating based Temperature monitoring system.The demodulation scheme of the system is to demodulate the temperature by the edge filter demodulation method.By using the reflected light from the fiber Bragg grating to enter the filter with a single-valued edge and the drift between the output light intensity and the center wavelength of the reflected light the corresponding relationship of fiber Bragg grating wavelength demodulation.The software and hardware design scheme and debugging of fiber Bragg grating temperature monitoring system are introduced in detail.The DSP TMS320F2812 chip is selected as the system microprocessor.Its powerful signal processing capability realizes ADC sampling of temperature sensing signal and demodulation of data signal As well as the display of data storage and transmission functions,through the LCD liquid crystal display will display the demodulated temperature,real-time monitoring of the system to achieve the purpose of the system.The experimental design of the whole temperature monitoring system is experimentally tested on the constructed fiber Bragg grating temperature monitoring system experimental platform.By analyzing and processing the obtained experimental data,it is verified that the long period fiber grating is used as the edge filter in the temperature monitoring system demodulation scheme in the temperature demodulation effect.The experimental system uses the wavelet transform soft-threshold method to reduce the noise of the collected temperature sensing signal,and compares the effect before and after use.Through the temperature monitoring system experimental platform to test the performance of the system requirements for the next study has laid a good foundation.