Design and Analysis of a Novel Dual FBG Accelerometer Based on Lantern Shape Metallic Shells

Abstract

A novel dual FBG (DFBG) accelerometer based on lantern shape metallic shells is designed and analyzed. The DFBG accelerometer is based on the push-pull structure, which is used to eliminate common noises and disturbances. The axial size of the DFBG accelerometer is shortened by special combination of the mass and the elastic shells. The size of the optimized DFBG accelerometer is only 24 mm×24 mm×24 mm. Vibration trial results show that the average acceleration sensitivity is about 9.4 pm/g between 30 and 300 Hz, the resonant frequency is about 1175 Hz, the orthogonal crosstalk beyond 100 Hz is -20.6 dB, and the background phase noise is -70 dB re rad/√(Hz) for interferometric detection method, which corresponds to a minimum detectable acceleration 6×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> g. This DFBG accelerometer has great superiority in composing small 3-D FBG accelerometers and ultra-large scale vector sensor arrays.