Two-dimensional fiber grating inclination sensor

Abstract

The invention relates to a two-dimensional fiber grating inclination sensor. The sensor comprises a counterweight ball, monitoring fiber gratings, a compensation fiber grating, short stainless steel columns, a protection casing and loose fiber tubes, wherein the main structure comprises the protection casing, the short stainless steel columns and an induction structure; the protection casing is asquare box with small holes at two corners for allowing the loose fiber tubes to pass through; the short stainless steel columns are located at the four corners of the square protection casing, have acircular cross section and are used for supporting the protection casing; the induction structure comprises the monitoring fiber gratings, the counterweight ball and the compensation fiber grating. The two-dimensional fiber grating inclination sensor is mainly theoretically based on a force balance principle, the monitoring mechanism is to generate two directional component forces in a plane whenthe counterweight ball is subjected to force balance, and accordingly, Bragg reflection wavelength of the fiber gratings changes along with the change of the out-of-plane angle of the sensor. Besides, the cross-sensitivity problem of fiber grating temperature and strain is solved by the compensation fiber grating. The two-dimensional fiber grating inclination sensor has definite structural stress, high response speed, high measurement precision and good stability, has a temperature self-compensation function, is easy to process and manufacture, is resistant to electromagnetic interference andhas better engineering application prospect.

Description

technical field [0001] The invention is based on optical fiber grating sensing technology, is a high-precision instrument for monitoring the inclination angle of soil, rocks and buildings, and belongs to the technical field of optical fiber sensing. Background technique [0002] Large-scale civil engineering projects such as communication tower projects, bridge projects, housing projects and large water tower projects are prone to tilting due to uneven settlement of the foundation, which not only affects the normal use of the structure, but also causes additional stress and even leads to structural damage, resulting in loss of life and property . Therefore, it is necessary to monitor the structural tilt state throughout the construction and operation periods. The traditional inclination sensor is based on the electromagnetic effect, capacitive effect, etc., and can achieve high accuracy and resolution. However, this type of weak current sensor has the disadvantages of poor ...

AI Technical Summary

Problems solved by technology

The traditional inclination sensor is based on the electromagnetic effect, capacitive effect, etc., and can achieve high accuracy and resolution. However, this type of weak current sensor has the disadvantages of poor anti-electromagnetic interference performance, large cable line loss, and short transmission distance. It is difficult to apply in strong electromagnetic field environment and anti-static environment such as coal mine and oil depot

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