Design and Modeling of a High Sensitivity Fiber Bragg Grating-Based Accelerometer

Abstract

Use of a detailed theoretical model has allowed the optimization of the design of a high sensitivity accelerometer, based on a fiber Bragg grating (FBG) and an accelerometer based on this design has been demonstrated experimentally. With a universal model based on double-point encapsulation established, the performance of the device in terms of its optimal sensitivity and frequency distribution has been analyzed, with an optimization 'figure of merit' using the product of the sensitivity and the resonant frequency being presented. The experimental results obtained indicate that the FBG-based accelerometer thus developed shows a broad, flat frequency band, a corresponding flat range sensitivity of ∼152.0pm/G, a resonant frequency of 441.0Hz, and a cross-axis sensitivity of less than 3.6% of the main-axis sensitivity. An accelerometer of this type and with this performance thus has the potential for the important field of low frequency oil-gas seismic exploration.

A strain-wavelength modelling of low-frequency cantilever fibre Bragg grating accelerometer

“…The recent works done by Liu et al. 33 has proved that the double-point encapsulation has increased the sensitivity of the FBG accelerometer and prevented FBG spectrum chirp and wavelength split, compared with the embedded encapsulation method, where the FBG is fully attached the beam, as presented in this paper. However, this work chose the embedded encapsulation because of the following reasons:From the authors’ experience, since the response (deflection) of cantilever beam at low frequency is very small, the induced strain is also very small and it does not create FBG spectrum chirp and wavelength split;The FBG grating was completely attached onto the beam; andFor the cantilever beam mechanism, there is a possibility of buckling occurring on the FBG if double-point encapsulation is used (double-point encapsulation lets the grating area move freely).…”

Fiber Bragg grating based acceleration sensors: a review

“…Compared with the sensor (Wang et al , 2015b) designed by Wang et al , in the same year, Wang et al (2015a) used two-point encapsulation mode and embedded two FBGs into the double-cylinder with the changed radius and designed an FBG acceleration sensor with higher sensitivity and resonant frequency by using the difference principle. To balance the sensitivity and resonant frequency of the sensor to achieve the optimal overall performance, Liu et al (2019) embedded the FBG into an elastic cylinder connected with the double-diaphragm by means of two-point encapsulation and designed an FBG acceleration sensor with high sensitivity in 2019, which has the potency for the important field of low-frequency oil-gas seismic exploration.…”

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

“…Substituting Equation ( 15) to (18) into Equation (19), the dynamic equation for the system can be described as follows:…”

“…A packaged FBG acceleration sensor is composed of a spring-mass system with one or several FBGs. Various elastic elements have been studied to form FBG acceleration sensors, including cantilever type [14][15][16][17][18], diaphragm type [19][20][21], and flexure hinge type [22][23][24][25][26][27]. In flexure hingebased acceleration sensors [23][24][25], the two sides of a flexure hinge are connected with the mass and the base, respectively, and the FBG is placed between the base and the inertial mass to realize the acceleration measurement.…”