| As an important member of fiber optic sensors,the reflective intensity modulated fiber optic sensor (ab. RIM-FOS) has won widely attention in the past forty years,because of its simple configuration,low cost,good reliability and flexibility. It has also been widely used in many industrial measuring situations such as displacement sensor in vibration measurement,as proximity sensor in robotics and automation control,as the readout element in a pressure sensor,etc. In this dissertation,several key problems are studied systematically,which include the reflective light field distribution,the mathematical models of RIM-FOS,corresponding theories and methods about intensity compensation,simulation and testing on the sensor property,as well as the computer simulation and testing system used to help sensor design. The main research concerns on the following lists.1. Firstly,the mathematical model of fiber pair with the factors of reflector shape and inclination is established. Then,the numerical simulation is fulfilled,along with a series of rules of the influence on intensity modulation property caused by multimode fiber parameters,the factors of reflector shape and inclination.2. The reflective light filed distribution is studied in great detail with diffraction approach,which is based on the quasi-Gaussian beam model of the light emitted from the multimode transmitting fiber and conclusions drawn by Beckmann on the scattering light from random rough reflector.3. Then,the mathematical models corresponding to the tri-fiber sensors and six types of fiber bundle sensors are established with the aid of fiber pair model. In addition,simulation research is carried out to obtain their theoretical properties.4. The formula to calculate the light splitting ratio of intensity compensation with light splitter is derived out. Two kinds of circumstances are discussed in detail,the one is laser polarization changing while the intensity keeping stable,and the other is the intensity changing with the polarization. Experiment is completed to verify the theoretical analysis and the resolvent is proposed as well.5. A new kind of fiber structure with random typed light splitting end is put forward,which is called FI typed fiber bundle and can achieve the intensity compensation. The comparison between the two compensation approaches is finished by experiments. The influence on intensity compensation accuracy corresponding to three approachesinduced by the beam direction shift is analyzed in pure mathematic way. Additionally,a novel compensation method with the neural network is studied in addition.6. The idea to aid the RJM-FOS design and fabrication with a computer simulation and testing system is brought out for the first time,as well as the optimum flow chart of sensor design and fabrication.7. The computer simulation and testing system is designed and realized with many kinds of key techniques adopted. It can carry out the functions of property simulation and testing of RJM-FOS. Parametric representation of the normalized property curve is studied.8. A series of representative experiments are planned and fulfilled to inspection the performance of the system. Results show that not only most types of RIM-FOS can be simulated by the simulation and testing system,but also any kind of which can be tested automatically. Also the system can work as soon as power on,while free of the disturbance of environment and power fluctuation of the light source.
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