深水监测用光纤光栅内封式悬臂梁力传感器

Deep-water Force Sensor of Cantilever Inside Packaged Fiber Bragg Gratings

针对深水恶劣环境中对耐压性和抗海水腐蚀能力的需求,提出一种新型的可用于深水力载荷监测、具有悬臂梁结构的光纤传感器。该传感器将光纤布拉格光栅封装于悬臂梁元件内部,利用悬臂梁材料的抗压和抗海水腐蚀能力对光纤形成保护,既保持了此类传感器结构简单、力学性能优异的特点,又具备了耐压抗腐蚀能力。实验研究表明:该传感器能在30 MPa(3 000 m水深)的水压环境中正常工作,水压灵敏度为-3.79 pm/MPa,力载荷灵敏度为2.79 pm/N,温度灵敏度为30.93 pm/℃。传感器对温度和水压环境因素的响应线性良好,相关系数均在0.99以上,便于补偿。此外,通过对照仿真计算与实验结果,分析了封装工艺和实验条件对传感器误差的影响。

The cantilever is widely used in fiber Bragg grating（ FBG） sensors for its excellent mechanics response characteristics. However,the FBGs are packaged in the most existing cantilever surfaces ofcantilever sensors. These sensors cannot survive in the deep water without high-pressure resistance and sea-water corrosion resistance. The new FBG sensor with cantilever structure is developed to monitor the force under the deep water. In order to resist the corrosion and pressure,the FBG was packaged inside the cantilever that is made by anticorrosion material. It is shown that it works properly at a pressure of 30 MPa,pressure sensitivity of-3. 79 pm/MPa,force sensitivity of2.79 pm/N and temperature sensitivity of 30.93 pm/℃. The wavelength change is well linearly to the temperature and pressure change,and all linearly dependent coefficients are higher than 0. 99. The further environmental compensation is feasible. According to the computer simulations,test results and sensitivity analysis,the error from the package craft and test conditions is obtained.