Fiber grating displacement sensor based on flexible hinge

The invention discloses a fiber bragg grating displacement sensor based on a flexible hinge. The fiber bragg grating displacement sensor comprises an elastic body, an optical fiber and a grating located on the optical fiber. The elastic body comprises a first rod, a second rod, a first connecting block, a second connecting block, a first flexible hinge, a second flexible hinge and a fourth flexible hinge. The first rod and the second rod are symmetrically arranged in a V shape, the first connecting block is located in a V-shaped opening and connected with the first rod and the second rod through the second flexible hinge and the fourth flexible hinge respectively, and the second connecting block is located at the tip end of the V shape and connected with the first rod and the second rod through the first flexible hinge and the third flexible hinge respectively. The displacement of the measured object causes the displacement of the second connecting block, so that the first flexible hinge and the third flexibl