Fiber grating vibrating sensor with temperature insensitivity, tunable damping and high precision

Abstract

The invention discloses a fiber grating vibrating sensor with temperature insensitivity, tunable damping and high precision. The fiber grating vibrating sensor comprises a cantilever beam. A permanent magnet is connected at the end portion of the cantilever beam. The upper side and the lower side of the permanent magnet are respectively provided with a sealing coil, wherein the sealing coils are the same in diameter and number of wire turns. The upper surface and the lower surface of the cantilever beam are respectively provided with a sensing grating, wherein the sensing gratings are symmetric. The sensing gratings are led out through transmission optical fibers. The gratings are stuck to the upper side and the lower side of the central axis of the cantilever beam with the constant strength respectively. Due to the fact that the cantilever beam can be stretched or compressed by vibration, the central wavelengths of the two sensing gratings can drift in the negative direction, the measurement of vibration acceleration can be achieved by demodulating the changes of the central wavelengths of the two sensing gratings, the signal measurement accuracy can be effectively improved by the adoption of the double-grating structure, the influences, caused by temperature changes, on the measurement result are eliminated, and the sensor has the temperature insensitivity.

Description

technical field [0001] The invention specifically discloses a temperature-insensitive damping tunable high-precision optical fiber grating vibration sensor. Background technique [0002] There are a lot of vibration phenomena in the field of engineering technology, and vibration measurement plays an important role in the health detection of large-scale equipment operation and fault warning. At present, most commonly used vibration detection methods are based on piezoelectric vibration sensors, which have the disadvantages of low measurement accuracy, poor stability, and are easily affected by electromagnetic interference, which greatly affects the measurement and analysis of vibration signals. Compared with traditional electrical sensors, fiber grating sensors have attracted more and more attention due to their characteristics of wavelength coding, high sensitivity, anti-electromagnetic interference, ability to work in harsh environments, and easy networking. The fiber grat...

AI Technical Summary

Problems solved by technology

The fiber grating sensor itself also has temperature and strain cross-sensitivity problems, which largely affects the application and popularization of the sensor.

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