Nonlinear error correction method for optical fiber Michelson interference vibration meter

Abstract

The invention relates to a nonlinear error correction method for an optical fiber Michelson interference vibration meter, and belongs to the technical field of optical fiber interference measurement.According to the invention, in the premise that positions of a first reflector and a second reflector do not need to be changed, by carrying out wavelength pre-scanning on a laser wavelength modulatable light source and utilizing a continuous change of an output laser wavelength to enable an optical path difference between a reference beam and a measurement beam of an interferometer to generate acontinuous change, an interference signal obtained by a detector generates at least one period of phase change and pre-extraction of characteristic parameters of the interference signal is implemented; and nonlinear error correction is implemented in the measuring process by utilizing the pre-extracted characteristic parameters, and high-accuracy vibration measurement is carried out. The nonlinearerror correction method for the optical fiber Michelson interference vibration meter, which is disclosed by the invention, implements pre-extraction on the characteristic parameters of the interference signal of the optical fiber Michelson interference vibration meter, can effectively solve a problem of correcting a nonlinear error in the interference measurement and particularly in the micro vibration measurement, and has the obvious technical advantages in the field of precision measurement.

Description

technical field [0001] The invention belongs to the technical field of optical fiber interferometry, and mainly relates to a nonlinear error correction method of an optical fiber Michelson interferometric vibrometer. Background technique [0002] With the rapid development of scientific research and the rapid improvement of industrial production levels, scientific research and industrial fields have also put forward higher requirements for displacement measurement, and the minimum change of vibration measurement is also developing towards the nanometer level. Optical fiber Michelson interferometric vibrometer is an instrument for high-precision displacement measurement using the principle of laser interferometry. It has the advantages of non-contact and high precision. A fiber optic Michelson interferometric vibrometer includes a laser wavelength-modulatable light source; the laser wavelength-modulatable light source performs sinusoidal modulation of the wavelength; a fiber ...

AI Technical Summary

Problems solved by technology

But this method also has certain problems: additional motion control components increase the complexity of the system and control, and inevitably affect the position stability of the first mirror, thus introducing measurement errors

However, this method also has certain defects: this method can only be used with a specific single-frequency interferometer optical path, and is not suitable for optical fiber Michelson interferometric vibrometers, and this method can only obtain the three differences of the characteristic parameters of the interference signal. DC offset error and unequal amplitude error parameters, but non-orthogonal error parameters cannot be obtained, so they are not universal

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