Fibre Bragg grating based accelerometer with extended bandwidth

Abstract

We have shown experimentally that the operable bandwidth of a fibre Bragg grating (FBG) based accelerometer can be extended significantly, without compromising its sensitivity, using a post-signal processing technique which involves frequency domain weighting. It has been demonstrated that using the above technique acceleration can be correctly interpreted even when the operating frequency encroaches on the region where the frequency response of the sensor is non-uniform. Two different excitation signals, which we often encounter in structural health monitoring applications, e.g. (i) a signal composed of multi-frequency components and (ii) a sinusoidal excitation with a frequency sweep, have been considered in our experiment. The results obtained have been compared with a piezo accelerometer.

Fiber Bragg grating based acceleration sensors: a review

“…Due to the structural characteristics of cantilever beam and simply supported beam, acceleration sensors fail to solve the problem that resonant frequency and sensitivity restrict each other seriously. For this reason, Wang et al (2011), Basumallick et al (2011), Basumallick et al (2013), Basumallick et al (2016), Basumallick et al (2020) and Guo et al (2013a, 2013b, 2013c), Li et al (2015a, 2015b, 2015c, 2015d) started with the vibration transfer efficiency to design a series of wavelength detecting FBG sensitized acceleration sensors. In 2011, Wang et al (2011) fixed the cantilever beam on a special triangle bracket to improve the efficiency of external vibration transmission.…”

“…From 2013 to 2015, Guo et al (2013a, 2013b, 2013c) and Li et al (2015a, 2015b, 2015c, 2015d) designed two acceleration sensors with the same performance by adopting similar methods (Basumallick et al , 2011; Basumallick et al , 2013). In 2016, Basumallick et al (2016) used the Teflon patch and special weighted processing method to design a sensitized acceleration sensor with widened working frequency band. In 2020, Basumallick et al (2020) further optimized the previous structure and used a composite cantilever beam made of a polyurethane layer on a polyimide layer and a polymer fiber with a diameter of 80 µ m to design two wide-band FBG accelerometers with different parameters for health monitoring of electrical machines.…”

“…Compared with common single-mode FBG, polymer FBG with higher sensitivity coefficient was implanted into the optimal position in the polyurethane layer away from the neutral layer of the cantilever beam, so that the sensor has better sensitivity while obtaining a wider working frequency band. The above sensors (Wang et al , 2011; Basumallick et al , 2011; Basumallick et al , 2013; Basumallick et al , 2016; Basumallick et al , 2020; Guo et al , 2013a, 2013b, 2013c; Li et al , 2015a, 2015b, 2015c, 2015d) are suitable for vibration measurement occasion where the high sensitivity is required, but they did not solve the problem of the temperature-strain cross-sensitivity.…”

Ultra-Small Fiber Bragg Grating Accelerometer

“…Fiber Bragg grating (FBG) has many intrinsic advantages, such as immunity to electromagnetic interference, electrical isolation, frequency modulation, and ease of multiplexing [2]. Many different FBG accelerometers have been developed [3][4][5][6][7][8][9][10][11][12][13][14][15]. Some FBG accelerometers used a springy stick to hold the inertial object at the equilibrium, and the FBG was attached to the springy stick [3][4][5][6].…”

“…Many different FBG accelerometers have been developed [3][4][5][6][7][8][9][10][11][12][13][14][15]. Some FBG accelerometers used a springy stick to hold the inertial object at the equilibrium, and the FBG was attached to the springy stick [3][4][5][6]. When the inertial object vibrated, the springy stick and FBG was pulled.…”