Fiber Bragg Grating Displacement Sensor With Double Cantilever Beam Model

Displacement measurement is one of the most basic measurement technologies,using a wide range of application in engineering and a very important position. Therefore,seeking a simple,easy to operate,adapt to a wide range,goode economy of displacement sensors for promoting the development of industrial production has important practical significance.Due to the unique electrical isolation of fiber Bragg grating to give immunity to electromagnetic interference (EMI) and the explosive nature of the occasion of the Ante, making fiber Bragg grating sensing technology rapidly developed. This paper developed a displacement measuring device, through wedge, displacement measuring device utilize measuring rode to operate on equal strength cantilever which fixes on base. Besides that, in one of these equal strength cantilevers, the fiber Bragg grating sticks to the centerline of its outer surface. In measurement process, the displacement of measure rode derives wedge to produce corresponding displacement. Moreover, the displacement changes the deflection of the free end on equal strength cantilever, which results in shifting wavelength length on the fiber Bragg grating simultaneously. The main completed work as follows:(1) The double cantilever beam structure, the establishment of Fiber Bragg Grating Displacement Sensor with Double Cantilever beam model.(2) On double cantilever beam Fiber Bragg grating displacement sensors for materials selection, the size of equal strength cantilever is 135×70.2x3mm,the material of the equal strength cantilever is 1Cr18Ni9Ti,The internal diameter of the wedge is 35mm,outer diameter is 50mm,the angle is 10 degrees,the length of measuring rode is 450mm,the diameter is 1.6mm,the size of the base is 380×120×12mm,the Knurling is cylindrical with the diameter of bottom surface of 30mm and the high 12mm and the high 12mm,the length of the roller is 80mm,the angle of roll is 60 degrees,the diameter is 6mm.In the case of shifting displacement, the experiment result of the fiber Bragg grating on central measuring point is shown as follows. The sensitivity of fiber Bragg grating on positive routine is 0.015nm/mm. Correspondingly, its sensitivity on negative routine is 0.014nm/mm, and its repeatable error is 2.2%. On the other hand, the linearity of it on positive routine is 0.99728.Furthermore, its linearity on negative routine is 0.99684, and its sluggish is 0.0626%FS.