A high-precision and large-range real-time single-point out-of-plane displacement measurement method

Abstract

The invention provides a high-precision wide-range real-time single-point out-of-displacement measuring method. According to the method, the direction and size of displacement are obtained in an image processing mode, and displacement is measured through a hardware device in a real-time tracking compensating mode. The measuring method is based on a two-beam interference principle, a pattern formed by interference of a reference end and an object end is recorded in a measuring system in the form of an image in the measuring process, displacement information is fed back to a precise actuator of the reference end through an image processing technology, and the aim of tracking the displacement at the object end through the reference end in real time is achieved. In image processing, the direction and size of displacement are judged based on the image gravity and the histogram related processing algorithm respectively; the tracking process is achieved in a successive approximation mode, and displacement can be calculated in real time through voltage values after the relation between displacement of the actuator and voltage is calibrated in advance.

Description

technical field [0001] The present invention proposes a high-precision and large-scale real-time single-point out-of-plane displacement measurement method, which is applicable to all interference systems based on the principle of double-beam interference, such as Michelson (hereinafter referred to as "Mayson") interferometer, Mach-Zeng German interferometer, etc. It can be applied to traditional Mayers interferometer application scenarios, such as out-of-plane displacement detection, liquid refractive index field detection, etc., and can also be applied to some application scenarios that have high requirements for real-time measurement, such as monitoring crystal growth and material linear expansion coefficient Measurement, etc., is a set of optical measurement methods proposed by integrating the knowledge of multiple disciplines such as photometric mechanics, image processing and automatic control. Background technique [0002] In recent years, with the rapid development o...

AI Technical Summary

Problems solved by technology

However, the measurement resolution of the optical imaging method is on the order of microns, which cannot adapt to the displacement measurement required by ultra-high precision; although the measurement method based on laser interferometry has high precision, it can reach a resolution of 1 / 100 wavelength to 1 / 1000 wavelength, However, its measurement range becomes a major drawback of this method

At the same time, in the full-field displacement measurement method, the fringe subdivision technology is often used to improve the measurement accuracy, but these technical operations will bring a large time overhead to the measurement method, making it unsuitable for work that requires high measurement time surroundings

Therefore, how to propose a measurement method that not only has the characteristics of high precision and non-contact measurement, but also can better overcome the contradiction between high measurement resolution and large range in the field of laser interferometry, and has a good time response, still faces many challenges. Technical problems, currently there is no report on related measurement methods in the world

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