Miniature bending-resistant fiber grating accelerometer based on a flexible hinge structure.

To meet the needs of vibration monitoring with special requirements for the size and quality of accelerometers, a miniaturized fiber Bragg grating accelerometer based on flexible hinges is proposed in this paper. The sensor uses a flexible hinge as an elastic body, and the suspended arc package realizes the miniaturization of the accelerometer. At the same time, the grating prepared by bending-resistant optical fiber successfully solves the problem of light loss in arc-shaped packaging. The structural model and principle of the accelerometer are introduced, and its sensing characteristics are analyzed theoretically and by simulation. The physical size of the prepared accelerometer is 17 mm × 12 mm × 10 mm, and its mass is only 4.44 g. The experimental results show that the resonant frequency of the accelerometer is about 900 Hz, the sensitivity is 26.962 pm/g in the flat range of 20-400 Hz, and the lateral interference is less than 5%. The accelerometer is suitable for medium and low frequency vibration monitoring in narrow spaces in aerospace and other fields.