High reflective surface three-dimensional vision measurement system and method

Abstract

The invention discloses a high-reflection surface three-dimensional vision measurement system and method. The method comprises steps of building a model between light intensity of a projector and the imaging gray level of a camera, projecting a uniform saturated gray level image, collecting the image at a high exposure time and a low exposure time, marking saturated pixels, obtaining an imaging region of a high-reflection region of an object surface in a camera image, calculating the low-gray-scale projection intensity which enables the image not to be saturated; carrying out camera pixel absolute phase judgment to obtain one or more camera pixels corresponding to each to-be-adjusted pixel in the projection image, and calculating the gray level of the projection pixel and the average gray level of the corresponding camera pixel to form a gray level matching pair; fitting projection intensity model parameters by taking the matched projection pixel gray scale and the camera pixel gray scale as samples; calculating optimal projection intensity according to the projection intensity model, and generating a self-adaptive sine image; a projector projecting a self-adaptive sine image, an industrial camera collecting the image, a multi-frequency heterodyne phase solving method being used for phase solving, and the three-dimensional shape of an object being obtained according to a fringe projection profilometry vision measurement model.

Description

technical field [0001] The invention relates to the technical field of three-dimensional measurement, in particular to a system and method for three-dimensional visual measurement of a highly reflective surface. Background technique [0002] 3D visual measurement technology can obtain the 3D shape information of the object surface with high precision, and is widely used in the fields of object surface reconstruction, defect detection, reverse engineering and so on. Among them, various metal parts in major national equipment projects such as aviation, aerospace, ships, and energy power, such as: water turbine blades, aircraft, ship and automobile shells and other highly reflective workpiece surfaces, pose challenges to accurate 3D visual measurement. [0003] At present, the three-dimensional shape detection technology of highly reflective surfaces mainly includes two types: contact detection and non-contact detection. As a commonly used contact detection method, the three-c...

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Problems solved by technology

As a commonly used contact detection method, the three-coordinate measuring machine has the disadvantages of complicated operation, low efficiency, and easy damage to the surface of the tested part.

However, this method ignores the quantization error caused by different resolutions in the process of coordinate matching, the generated adaptive image is not accurate, and the process of fusion is cumbersome.

[0006] It can be seen that the existing high-reflective surface measurement method based on adaptive fringe projection is inaccurate or complex in obtaining low gray levels, inaccurate in adjusting projection pixels, and ignores quantization errors caused by different resolutions. The experimental process and three-dimensional The accuracy and completeness of reconstruction cannot meet the requirements of engineering practice

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