Inclination Sensor Based on Fiber Bragg Grating and Its Inclination Measurement Method

Abstract

The invention relates to a tilt angle sensor based on optical fiber Bragg gratings and a method for measuring a tilt angle of the tilt angle sensor and belongs to the technical field of measurement of a structural tilt angle. The tilt angle sensor comprises a fixed base plate (12), a fixed pressing block (6), a thin-wall type uniform-section metal beam (9) and a quality block (7), wherein the upper end of the thin-wall type uniform-section metal beam (9) is arranged on the fixed base plate (12) in a mode of fitting with the fixed pressing block through a first movable pressing block (10) and a fifth screw (11); the quality block (7) is fixed at the lower end of the thin-wall type uniform-section metal beam (9) through a sixth screw (15) and a second movable pressing block (16); and a first optical fiber Bragg grating (13) and a second optical fiber Bragg grating (14) are respectively adhered to opposite positions on two sides of the thin-wall type uniform-section metal beam (9). By the method, the size and direction of the tilt angle can be detected according to a correspondence relation between the change of central wavelengths of the two optical fiber Bragg gratings and the tiltangle. The invention is high in measurement accuracy and has a temperature self-compensation function.

Description

technical field [0001] The invention relates to an inclination sensor based on a fiber Bragg grating and an inclination measuring method thereof, belonging to the technical fields of structural inclination measurement and optical fiber sensing. Background technique [0002] At present, the inclination sensor can be divided into three types: gas pendulum type, liquid pendulum type and solid pendulum type in terms of working principle. The gas pendulum type has strong anti-vibration or impact ability, but the gas motion control is more complicated, and the measurement accuracy is not high. The liquid pendulum type inclination sensor system is stable and widely used in high-precision systems, but the measurement range is small and the requirements for the measurement environment are relatively high. The solid pendulum angle sensor has a definite pendulum length and pendulum center, and the practical product type is mostly electromagnetic pendulum type, which has a high measure...

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Problems solved by technology

[0003] Research scholars of Huazhong University of Science and Technology [Wu Xianzhi, Ren Weixin, "Development of a new fiber grating inclination sensor", Journal of Huazhong University of Science and Technology, 25(4), 332-334(2008)] proposed a method for civil engineering Compared with traditional mechanical and electromagnetic measurement methods, the fiber grating inclination measurement method for monitoring has improved the design cost and structural complexity to a certain extent, but this method still has the following technical problems and defects: ① Since the pendulum directly It is sleeved on the shaft, and the inclination measurement is realized through the deflection around the shaft. However, in actual inclination measurement, especially in occasions where high measurement accuracy is required, the friction between the pendulum and the shaft and the fixing method of the pendulum and the strain beam are different. It will bring a large uncertainty error to the measurement, which limits the practical application of the sensor; ②Due to the limitation of measurement sensitivity, the sensor is only suitable for small angle measurement, and cannot expand the range detection range according to actual engineering needs

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