A Medium-Frequency Fiber Bragg Grating Accelerometer Based on Flexible Hinges

Abstract

Mediumfrequency fiber Bragg grating (FBG) acceleration sensors are used in important applications in mechanical, aerospace and weapon equipment, and have strict requirements in terms of resonance frequency and sensitivity. A novel medium-frequency accelerometer, based on fiber Bragg grating and flexible hinges, is proposed in this paper. The differential structure doubles the sensitivity of the sensor while avoiding temperature effects. The structure model and principle for the sensor are introduced, the sensor’s sensing characteristics are theoretically analyzed, and the structure parameters for the sensor are determined through numerical analysis. The sensing experiments show that the resonance frequency of the sensor is approximately 2800 Hz, the sensitivity is 21.8 pm/g in the flat frequency range of 50–1000 Hz, and the proposed sensor has a good temperature self-compensation function and lateral anti-interference capability.

A Low-Frequency Fiber Bragg Grating Acceleration Sensor Based on Spring Support and Symmetric Compensation Structure with Flexible Hinges

“…The sensor recorded a resonant frequency of approximately 1700 Hz and a sensitivity of 23 pm/g, with an operational frequency range of 500-1400 Hz. Li, Z et al (2021) [16] designed a medium-and high-frequency dual fiber Bragg grating (FBG) vibration sensor utilizing a straight circular hinge. The resonant frequency of the sensor is approximately 2800 Hz, with a sensitivity of 21.8 pm/g within a flat frequency range of 50-1000 Hz.…”

High sensitivity optical fiber accelerometer based on symmetric hinge structure with dual mass blocks

“…When the structure is the same, high stiffness leads to high intrinsic frequency, while high mass leads to low intrinsic frequency. The commonly used structures of elastomers include diaphragms [10], hinges [11][12][13][14][15], and cantilever beams [16,17]. The hinge structure is widely used among them.…”

“…In harsh usage scenarios, the effective packaging method of FBG can also affect the performance and lifespan of the accelerometer. Usually, FBG packaging is divided into embedded packaging [20] and two-point packaging [10][11][12][13][14][15][16]. The area of embedded packaged optical fibers includes the FBG gate area, and the curing of the packaging material may cause uneven stress and chirping in the FBG gate area.…”