Development of Three-component FBG Vibration Sensor for Measuring Vibration, Temperature and Verticality Simultanously

Jiang shan-chao, Wang jing*, Sui qing-mei, Ye Qing-lin, Wang li-jun

(School of Control Science and Engineering, Shandong University, Jinan 250061, China)

Journal of Sensors

Abstract: In order to achieve simultaneous measurement of vibration, temperature and verticality, a three-component fiber Brag grating vibration (TVFBG) sensor is proposed in this article. Polymer and metal diaphragm sensitization are both utilized to increase detection sensitivity of this sensor and project matrix theory is adopted to analyze its calculation model. Theoretically, a 9×9 nonsingular measuring coefficient matrix of this TVFBG sensor made up by three 3×3 measurand coefficient matrixes is established. To effectively extract and identify the measurand, Hilbert-Huang Transfer (HHT) is utilized to deal with detection signal of this TVFBG sensor. Calibration experiment is carried out to verify the performance of this sensor. Experiment data confirm that this sensor has excellent frequency response ability and shows good linearity at temperature and verticality measurement. Wrist rotation angle measurement experiment is also implemented to explain signal processing and further identify this sensor practical value. After HHT analysis, the angle measurement sensitivities of three fiber Brag gratings (FBG1, FBG2, FBG3) included in this TVFBG sensor are -25.2 pm/°, 38.2 pm/°, and -38.3 pm/° separately. 

Index Terms: Hilbert-Huang Transfer (HHT); fiber Bragg grating (FBG); project matrix theory; wrist rotation angle