Research On Linear/Angular Plastic Optical Fiber Distance Sensor

Relative to the interferometric fiber optic displacement sensor,the intensity modulation fiber optic displacement sensor with simple structure,reliable performance,low cost,design flexible,fast response speed,and other advantages in non-contact precision displacement measurement has been widely applied.Previously,most of the research is based on the silica fiber as sensing materials.Compared with the traditional silica optical fiber,plastic optical fiber has the advantages of a large numerical aperture,the low cost,good toughness,has extensive application prospect in the field of optical fiber sensing.This thesis "Research on linear/angular plastic optical fiber distance sensor" is use plastic optical fiber as transmission fiber,based on the theory of differential modulation,the intensity modulation linear/angular displacement sensing technology are studied,for the purpose of high sensitivity,strong anti-jamming capability of optical fiber displacement sensor is developed to provide theoretical and experimental basis.The main contents include:There is a radial distance between initial based on optical fiber optical fiber on line/angular displacement sensors photosensitive emphasizes the system characteristic,the differential intensity modulation fiber-optic lines/angular displacement sensor technology has been put forward.Based on the strong fluctuation of improving the system sensitivity,inhibiting the light source,the purpose of bipolar linear/angular displacement has been achieved,and establishing function mode of light intensity,further analyzed the influence of sensor's characteristic function to light intensity with modulation characteristics.We can offer theoretical and experimental basis of absolute tracking measurement of optical fiber line/angular displacement development in order to improve sensitivity,strong anti-jamming.Selecting appropriate light source and photo detector after determining the design overall program to optical fiber linear/angular displacement sensor which is the basis,and based on the theory of weak signal detection complete the design to photoelectric signal processing circuit.The system mainly includes light source modulation,photoelectric detection,preamplifier,band-pass filtering,phase sensitive detection and low pass filter.The design of data acquisition system has been finished that includes A/D conversion,USB data transfer,the FPGA control and PC.providing experimental conditions for the proposed theoretical model validation.Finally,by the experiments verified the reliability of differential transmission optical fiber displacement sensor principle,the differential transmission tilting of optical fiber displacement respectively.