Study On The Characteristics Of Cantilever-type Fiber Bragg Grating Accelerometer

The fiber grating sensing technology derived from the generation of the fiber grating has been widely used in the social production by people, such as the inspection of bridge and road conditions, the quality test of the building as well as the measurement of the braking acceleration in the automobile industry, providing a new approach in signal detection under the complex geographical conditions and the dangerous conditions for human.This paper is centered on an aspect of the field of fiber grating sensor acceleration sensor technology. The basic idea is to realize the measurement of the external stress or the signal of acceleration through demodulation of the FBG wavelength, based on a variety of cantilever beam structure.At first the thesis introduces the working principle of sensor model based on the quality - spring structure as well as the impact on cantilever by different forms of acceleration signal, then introducing the physical properties of sensors of several common cantilever structure, including the deflection and the angle relating to the stability of the cantilever. On the basis of the study above, this article takes a novel isosceles triangle dual- cantilever structure as a sensing device to compensate for some shortcomings of cantilever beams above and proves the superiority of the structure theoretically in compensating for the angle of the end of cantilever beams, based on the understanding of the unbalance of common rectangular cantilever axis's stress and the angle of the end of isosceles triangle being too large. Finally, the thesis analyses the characteristics of the reflectivity of fiber Bragg grating pasted on the surface of a variety of cantilever and the relationship between the reflectivity and the stress outside world as well as the relationship between the wavelength and the stress, theoretical research and analysis on resonance acceleration in ideal state, and makes numerical Simulation in chirped fiber grating reflection spectrum induced by cantilever and the relationship between the wavelength and the stress, fitting the change of the acceleration of the beam's end.