Rotating cantilever-based low-frequency double-fiber grating acceleration sensor

Acceleration sensors play an important role in bridges, dams, seismic monitoring, geological exploration, and more. Aiming at the problem that it is still difficult to accurately measure low-frequency vibration signals with low-frequency acceleration sensors, a high-sensitivity, wide-low-band fiber Bragg grating (FBG) acceleration sensor incorporating a rotating cantilever and springs was proposed. A sensor mechanics model was built, and its key parameters were analyzed theoretically and optimized in size. ANSYS Workbench was used for simulation analysis, and the physical sensor was developed while a low-frequency test platform was established for performance tests. The experimental results suggested that the natural frequency of the sensor was 78 Hz, the operating frequency band was 1-55 Hz, the sensitivity was 1127.2 pm/g, the transverse interference immunity was less than 5.45%, and the dynamic range was 86.45 dB. With high sensitivity, wide low frequency band, and excellent temperature compensation characteristics, the designed sensor could provide a reference for the design of like FBG acceleration sensors.