DISPLACEMENT MEASUREMENT METHOD BASED ON OPTICAL FIBER STRAIN SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a means for precisely detecting a displacement position, a displacement amount, and the displacement direction of a measurement object by means of an optical fiber strain sensor.;SOLUTION: The optical fiber strain sensor S1, in which first-fourth light guide paths F1-F4 formed of optical fibers and arranged along the axial line are sequentially arranged at equal intervals with a phase difference of 90° around a pipe 1, is used. When it is assumed that a strain value of the first light guide path F1, a strain value of the second light guide path F1, a strain value of the third light guide path F1, a strain value of the fourth light guide path F1 in the measured strain position are represented by ε₁, ε₂, ε₃, and ε₄, an angle θ made by the direction connecting the first light guide path F1 and the pipe center O together and the displacement direction P is calculated according to the following expression; θ = tan^-1[|ε₂-ε₄|/|ε₁-ε₃|].;COPYRIGHT: (C)2004,JPO