Compact FBG accelerometer with adjustable multi-cantilever beams: high sensitivity and robustness for industrial vibration sensing

Abstract Vibration monitoring plays a crucial role across various domains. However, traditional piezoelectric accelerometers have significant application limitations. Therefore, fiber Bragg grating (FBG) accelerometers have gained attention as an emerging research focus. This paper presents a compact multi-cantilever beam FBG accelerometer, which utilizes a parallel configuration of multiple cantilever beams to transmit inertial forces, thereby inducing deformation in the fiber grating. By optimizing the cantilever beam width, the resonant frequency and sensitivity can be flexibly adjusted. Simulations of the structural parameters and finite element analysis were carried out using COMSOL software to determine the optimal design parameters for the sensor. Experimental results demonstrate that the sensor achieves a resonant frequency of 676.88 Hz and a sensitivity range of 8.17–39.88 pm g −1 within the 100–500 Hz frequency range. It exhibits linearity exceeding 99% and a transverse response below 6% of the working direction, indicating robust anti-interference capabilities. The sensor’s performance in air compressor vibration monitoring was compared with standard piezoelectric accelerometers, validating its accuracy and reliability. With its superior high-frequency response, compact form factor, and outstanding performance, this sensor provides an efficient solution for vibration monitoring in complex environments, demonstrating significant practical value in real-world applications.