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Research On Reflective Optical Fiber Displacement Sensing Technology With Inclined Fibers

Posted on:2020-03-09Degree:MasterType:Thesis
Country:ChinaCandidate:Y Y YangFull Text:PDF
GTID:2428330590984211Subject:Microelectronics and Solid State Electronics
Abstract/Summary:PDF Full Text Request
Optical fiber sensors are widely used in the monitoring of physical quantities such as temperature,humidity,refractive index,pressure,displacement and vibration because of offering many advantages such as simple structure,small size,immune to electromagnetic interference,low cost and high measurement accuracy.There are two main modulation methods of measuring displacement using fiber optic sensors: intensity modulation and wavelength modulation.Among them,the reflective intensity modulation fiber optical displacement sensors(RIM-FODS)is a relatively classic type of light intensity modulation type sensor.It has the advantages of flexible design and non-contact measurement.It has been successfully applied to displacement,angular displacement,vibration surface roughness,et al.This paper first introduces the basic situation of fiber optic sensors,and seriously summarizes the research status of reflective light displacement sensors.Subsequently,the theoretical model and intensity modulation function of the reflective intensity modulation sensor are established on the premise that the optical fiber exits the light field obeying uniform distribution and specular reflection.On this basis,the theoretical model and intensity modulation function of RIM-FODS with inclined fibers are established.Numerical simulations are made to study the influence law of the core radius and NA of the transmitting fiber,the core radius of the receiving fiber,the tilt angle of the fibers,and the structural parameters of the sensor.In order to eliminate the influence of the output power fluctuation of the light source,the transmission loss of the optical fiber and other factors on the output of the sensor,a light source with automatic power control is used,and a receiving fiber is additionally introduced to form a displacement sensor with the double receiving fibers,and the ratio of the two receiving fibers is adopted to achieve intensity compensation of the sensor.Finally,the output characteristics of the sensor are verified experimentally,including the influence of the fiber tilt angle on the transmission curve,the repeatability and stability of the sensor.In addition,it is compared with the measurement results of the Michelson interferometer,and the measurement deviation of the two sensors is only 2.98%,and the sensor is used to measure the resonant frequency of the cone-type speaker with a measurement error of 1%.
Keywords/Search Tags:Optical fiber sensors, intensity modulation, reflective, intensity compensation
PDF Full Text Request
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