Low-frequency accelerometer based on fiber grating

Abstract

The invention discloses a low-frequency accelerometer based on a fiber grating. The accelerometer comprises a pedestal, two symmetrical elastic mass assemblies are arranged on the pedestal, each elastic mass assembly comprises a mass block and a bending spring, the mass block is placed under the bending spring, one end of the bending spring is connected with the pedestal, the other end of the bending spring is pressed on the pedestal by the mass block, and the fiber grating is placed on the bending springs and adhered to the bending springs. The bending springs vibrate to enable axial strains in opposite directions at the two ends of the fiber grating, an axial strain sensing mechanism of the fiber grating is utilized to measure the acceleration, and the measuring sensitivity is multiplied. A fiber is used to transmit sensing signals, measurement and transmission are integrated, and the low-frequency accelerometer based on the fiber grating further has the advantages including high sensitivity, high performance in anti-electromagnetic interference, and capability of long-distance monitoring.

Description

technical field [0001] The invention belongs to the technical field of acceleration sensors, in particular to a low-frequency acceleration sensor based on a fiber grating. Background technique [0002] Low-frequency vibration widely exists in production practice, and its vibration frequency is generally below 100Hz. For example, the vibration frequency of large hydroelectric generating units is below 15Hz; the natural frequency of general road and railway bridge vibration is about 2-10Hz; the engineering earthquake pulsation frequency is generally between 2-50Hz. The monitoring of these low-frequency vibrations often uses electrical sensors to pick up signals, but in a strong electromagnetic field environment, it is difficult for electrical vibration sensors to overcome the interference of electromagnetic fields. Its application is also limited, and the acceleration amplitude of low-frequency vibration is small, and the measurement is difficult. Therefore, a non-electrical ...

AI Technical Summary

Problems solved by technology

The monitoring of these low-frequency vibrations often uses electrical sensors to pick up signals, but in a strong electromagnetic field environment, it is difficult for electrical vibration sensors to overcome the interference of electromagnetic fields. Its application is also limited, and the acceleration amplitude of low-frequency vibration is small, and it is difficult to measure, so a high-sensitivity non-electrical acceleration sensor is required

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