Cantilever vibration sensor based on Fiber Bragg Grating temperature compensation

Abstract

To improve the sensitivity of fiber Bragg grating (FBG) vibration sensor and reduce the influence of temperature on vibration detection, an FBG vibration sensor with equal strength beam as elastic structure and temperature self-compensated is proposed. The working principle of the sensor is analyzed, the resonant frequency and the sensitivity are derived through the formula, the structural parameters are optimized, and its good response characteristics are proved by experiments. The theory of the proposed sensor is verified by experiments, and the experimental results show that the temperature impact on the sensor structure is reduced to 0.17 pm/°C in the range of 30–75°C. The sensor has a good response flat region at 20–220 Hz, the sensitivity is 149.8 pm/g. and the transverse sensitivity is only 3.95 % of the sensitivity in the working direction. Experiments show that the sensor has good comprehensive characteristics. Therefore, the sensor has great application prospect in vibration signal detection in the environment with obvious temperature changes, such as oil exploration, aerospace and so on.