Optical-fiber-grating acceleration sensor based on double-axis flexure hinge and measuring method

Abstract

The invention provides an optical-fiber-grating acceleration sensor based on a double-axis flexure hinge. The optical-fiber-grating acceleration sensor comprises a supporting piece capable of being installed on a measured body, a lower groove is formed in the upper end face of the supporting piece, a sensing core penetrates through the lower groove, and is fixed to the supporting piece through a pressing block with an upper groove, and the upper groove is matched with the lower groove; the sensing core comprises a flexure hinge penetrating through the upper groove and the lower groove, the twoends of the flexure hinge are each provided with a coasting body integrated with the flexure hinge, four optical fiber grooves are evenly formed in the circumferential direction of each coasting body, four optical fibers are mutually non-interactive and are put into the optical fiber grooves of the two coasting bodies at certain pre-tightening force, the two ends of each optical fiber are fixed,and the suspension part, located between the two coasting bodies, of each optical fiber is provided with a grating. According to the optical-fiber-grating acceleration sensor, the double-axis flexurehinge is an elastic component, the high natural frequency is kept while the sensitivity is improved, and in the two-dimensional plane of the measured acceleration, all directional sensitivities are same, the two-phase acceleration can be accurately measured, and the optical-fiber-grating acceleration sensor also has the temperature compensation effect.

Description

technical field [0001] The invention belongs to the technical field of mechanical vibration measurement, and in particular relates to a fiber grating acceleration sensor for a biaxial flexible hinge and a measurement method. Background technique [0002] In recent years, fiber grating sensors have developed rapidly with the advantages of lightness, safety, easy telemetry, strong anti-electromagnetic interference, high temperature resistance and corrosion resistance. At present, the common fiber grating two-dimensional vibration acceleration sensors mainly include the following two types. One is to use structures such as diaphragms, elastic sheets, elastic beams or springs to withstand the external force caused by acceleration, and to measure the acceleration by measuring the strain of the elastic structure through fiber gratings. ; The second is to directly use the fiber grating as the elastic element to bear the inertial force caused by the acceleration, and obtain the acce...

AI Technical Summary

Problems solved by technology

Acceleration sensors with structures such as elastic beams and diaphragm springs as elastic elements have good sensitivity and frequency characteristics and can meet the needs of low-frequency vibrations. However, the dynamic characteristics of this structure will be affected by the stiffness of the structure, and the overall structure size is too large. For the measurement of two-dimensional acceleration, it is difficult for this type of sensor to ensure the same sensitivity in all directions, and the measurement results are not accurate enough

The acceleration sensor that directly uses the fiber grating as the elastic element has the advantages of simple structure, small size, and good repeatability, but it also has the disadvantages of short life and the inability to obtain high sensitivity and resonance frequency at the same time.

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