Three-dimensional shape measurement method of large curvature mirror based on phase deflection of curved screen

Abstract

The invention discloses a method for measuring the three-dimensional shape of a large-curvature mirror surface based on the phase deflection of a curved screen. Firstly, a measurement system is built, and then system parameters are calibrated. After obtaining corresponding parameters through a reference plane mirror, the measured mirror surface is used to replace the reference plane mirror to solve The height information of the measured mirror surface. This measurement method establishes a direct calculation formula for the height of a large curvature mirror surface based on the phase deflection of the curved surface, avoids the complicated gradient integration and numerical analysis process, and can realize the depth measurement of the discontinuous mirror surface. This measurement method uses the curved screen as the structured light source for the phase deflection technique for the first time, which expands the range of the measurement field, expands the measurement height field and gradient field of the mirror measurement phase deflection technique, and realizes the effect of measurement field amplification.

Description

technical field [0001] The invention relates to the field of optically measuring the three-dimensional shape of mirror objects, in particular to a method for measuring the three-dimensional shape of a large-curvature mirror based on phase deflection of a curved screen. Background technique [0002] With the rapid development of modern society, various industries have increasing requirements for the acquisition of three-dimensional shape information of objects, such as the reverse reconstruction of precision parts in manufacturing, and the accurate acquisition of the shape of cultural relics in the digitization of cultural relics information. For this reason, various precise 3D shape acquisition methods have emerged, such as active optical measurement, passive optical measurement, contact measurement, etc. The above methods have their own advantages and disadvantages. For example, passive optical measurement technology is widely used in the field of machine vision, and is mos...

AI Technical Summary

Problems solved by technology

[0007] Although the existing mirror surface measurement technology can accurately realize the measurement of continuous and discontinuous mirror surfaces, and has high measurement efficiency, all of them use flat screens, and there is a disadvantage that the curvature of the measurable mirror surface is too small

Existing PMD and DPMD technologies both use small flat LCD displays or gratings as structured light sources, which cannot measure surfaces with large height changes and gradient changes, that is, the three-dimensional shape of large curvature mirrors.

When the curvature of the mirror changes greatly, part of the mirror reflects the scene outside the screen, and it is impossible to perform three-dimensional measurement on this part of the mirror.

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