Design Of Fiber Bragg Grating Displacement Sensor Based On ARM-Cortex Microcontroller

FBG (Fiber Bragg Grating) sensor is one of the hot pots in the field of fiber grating sensors research. FBG has been widely used for quality and safety detecting in bridges, dams and other large construction, and it has been used for highway vehicle overloading or overspeed monitoring, detecting structural quality of aerospace and submarine areas. Currently many departments and research institutions in nature and abroad carried out a lot of research on displacement detected, and taking the fiber grating technology as a method of measurement is one of the most highest-profile research methods.At present, the most of the fiber bragg grating displacement sensors for measuring displacement, more or less subjects to the changes of ambient temperature, making the experimental results and theoretical values deviate too much. This paper mainly analysis the principle of fiber Bragg grating sensor signal demodulation, and design a cantilever which tuning and matching based on grating demodulation technique of fiber bragg grating sensor signal demodulation technology programs. This paper derive the relationship between the difference of the peak wavelengths of fiber bragg grating and the cantilever free end displacement. In accordance, using pairs of fiber Bragg grating and an appropriate size to design the cantilever experiment. This paper designed part of the modem optical light path, including the light source and the coupling aspect. Based on the optimized fiber grating demodulation method, this paper uses semiconductor laser as light source and aim at its characteristics and make the necessary adjustment, and then designed the photoelectric signal converter and the voltage signal amplification circuit. Using ARM-Cortex Microcontroller to collect signal figures and program operation, the LCD real-time displays voltage.Finally, the two fiber grating which paste on the cantilever free end reflect wavelength peak achieves a linear tuning, and it may also make tuning range, sensitivity, and other indicators of flexibility under control. So that It effectively eliminates the effort of the surrounding temperature change on the impact of displacement sensor. It is derived the relationship between the size of FBG wavelength and the displacement of the cantilever free end, and carried out data processing and error analysis.