Study on 3D CFBG vibration sensor and its application

Abstract

A novel variety of three dimensional (3D) vibration sensor based on chirped fiber Bragg grating (CFBG) is developed to measure 3D vibration in the mechanical equipment field. The sensor is composed of three independent vibration sensing units. Each unit uses double matched chirped gratings as sensing elements, and the sensing signal is processed by the edge filtering demodulation method. The structure and principle of the sensor are theoretically analyzed, and its performances are obtained from some experiments and the results are as follows: operating frequency range of the sensor is 10 Hz‒500 Hz; acceleration measurement range is 2 m·s^-2‒30 m·s^-2; sensitivity is about 70 mV/m·s^-2; crosstalk coefficient is greater than 22 dB; self-compensation for temperature is available. Eventually the sensor is applied to monitor the vibration state of radiation pump. Seen from its experiments and applications, the sensor has good sensing performances, which can meet a certain requirement for some engineering measurement.

Keywords

Three-dimensional (3D) / matched / chirped fiber Bragg grating (CFBG) / edge filtering demodulation / crosstalk

References

[1] Zheng Y.. Vibration monitoring and analysis for rotating machinery. Gas Tribine Technology, 2010, 23(1): 39-48.

[2] Fu D., Wang Y.. The research of on-line vibration monitoring system of rotating machinery. Machine Tool & Hydraulics, 2005, 1, 152-153.

[3] Q. M. Nan, “Study on dynamic sensing and monitoring methods for petrochemical facilities based on optical fiber grating,” Ph.D. dissertation, Dept. Wuhan University, China, 2014.

[4] Zhou Z., Liu Q., Ai Q., Xu C.. Intelligentmonitoring and diagnosis for modern mechanical equipment based on the integration of embedded technology and FBGS technology. Measurement, 2011, 44(9): 1499-1511.

[5] Nan Q. M.. Study and application of CFBG vibration sensor with symmetrical push-pull configuration. in the 22nd International Conference on Optical Fiber Sensor, 2012 15-19.

[6] Wang G., Xie B.. Improving the performance of chirped fiber grating with cladding being etched as sinusoidal function. Optik International Journal for Light and Electron Optics, 2010, 122(6): 557-559.

[7] Zhao Y., Li Z.. Study on tri-axial accelerometer based on FBG. Chinese Journal of Scientific Instrument, 2006, 27(6): 299-301.

[8] Wang J., Chen C., Tang D., Zhang C., Cui Y.. Three-component photo-elastic fiber optic accelerometer based on the photo-elastic effect. Chinese Journal of Sensors and Acuators, 2006, 19(3): 804-806.

[9] Ding L., Zhao J., Wang J., Sui Q.. Design of FBG vibration sensor based on matching filter demodulation. Electro-Optic Technology Application, 2009, 24(3): 36-39.

[10] Nan Q.. Research on 3D FBG Accelerometer and demodulation method. Chinese Optics Letters, 2014, A01, 149-153.