Research On Torque Sensing Technology Using Polymer Optical Fiber

In the actual production and application, torque is an important parameter of rotating power machinery, which can reflect the functional mode of the entire mechanical system. Torque measurement technology has widely used in research and development, fault diagnosis, optimal control of various mechanical products, such as large ships, power generation, household appliances and band switch. Polymer optical fiber sensing technology, as a new sensing technology type, has many advantages compared with electrical sensing technology, such as snit-electromagnetic interference, easy to connection coupling, high sensitivity, high flexibility, low cost and easy to demodulate.The macro bend loss principle of polymer optical fiber will be applied to torque measurement technology. Through theoretical analysis and experimental research, a new way to measure torque is explored based on polymer optical fiber. Main contents include the following:1) Theoretical Analysis of polymer optical fiber torque sensor based on intensity modulation are completed. The structural characteristics of polymer optical fiber and the factors that cause light transmission loss in polymer optical fiber are analyzed. The macro bend loss of polymer optical fiber is studied detailed. The basic principles of torque measurement are analyzed, and the relationships between torque and shear strain, torsion angle, shear stress are determined theoretically. The strain torque sensor is studied detailed.2) A mathematical model between light attenuation and torque in ideal sensor’s structure is established. The elastomer structure and material are analyzed by the simulation, which impact the sensitivity and linearity of sensor. The parameters of elastomer structure and the paste method of strain film are determined.3) A torque measurement system is established. The measurement errors of polymer optical fiber intensity modulation measuring system are analyzed, and a sensing system structure is established. In order to reduce system noise, light source module, coupling light path, optical signal detection module and signal acquisition and processing module are designed. The system meets the requirements of measurement.4) Experimental studies of polymer optical fiber torque sensor are completed. The experiment mainly includes two parts. Firstly, the different sensor structures’strain experiments are studied. A new polymer optical fiber sensing structure is explored by analyzing, which has simple structure, good linearity and high sensitivity. Secondly, the new polymer optical fiber torque sensing system is designed, and the static performances of sensors including linearity, repeatability and hysteresis have been studied detailed.The researches have shown that the torque sensing technology based on polymer optical fiber has good linearity, repeatability and hysteresis. It has great application prospect in the field of torque measurement.