Multiple-line-structured-light visual measuring method based on homography matrix

Abstract

The invention discloses a multiple-line-structured-light visual measuring method based on a homography matrix. The method comprises two steps of constructing a multiple-line-structured-light measuringmodel based on stereo vision, and matching parallel structure light strips based on the homography matrix. The method settles problems of complicated line-structured-light sensor calibration, requirement for a specific calibrating object and the like in an existing structured-light vision measurement process. The homography matrix is utilized for representing the matching relation of the line-structured-light strips in a left-and-right view so that calculation of a light plane equation is not required in calibration of the line-structured light sensor. Only calibration of the homography matrix which corresponds with the light plane by means of two-dimensional image matching points is required, and then a binocular parallax principle is used for reconstructing the three-dimensional space coordinates of the structured-light strips. Furthermore feasibility of performing line-structured-light vision measurement by means of the homography matrix is verified through experiments. The experiment result proves a fact that the method is simple in operation and is suitable for field calibration and measurement.

Description

technical field [0001] The invention relates to the field of measurement technology, more specifically, it relates to a multi-line structured light vision measurement method based on a homography matrix. Background technique [0002] In active vision measurement technology, structured light vision measurement has the characteristics of non-contact, fast speed, and high efficiency, and has become one of the commonly used measurement methods in high-speed online inspection, quality control, and reverse engineering. Among them, line structured light has been widely used in the field of industrial detection due to its high detection accuracy, good stability, and strong adaptability. The calibration of the line structured light measurement system is the basic link of the entire measurement process, and the accuracy and stability of the calibration directly determine the accuracy and stability of the subsequent measurement links. The calibration of the line structured light visio...

AI Technical Summary

Problems solved by technology

[0003] The traditional linear structured light plane calibration methods mainly include the drawing calibration method, the calibration method based on three-dimensional targets and cross-ratio invariance, and the sawtooth target method. These three calibration methods all require sophisticated calibration auxiliary equipment, and the calibration process is relatively complicated. , and not suitable for on-site calibration

In response to this problem, someone proposed a line-structure cursor calibration method based on a plane reference object. Its advantage is that the calibration equipment is easy to manufacture and easy to carry out on-site calibration. However, this method needs to establish a local world coordinate system on the plane calibration board, and the calibration board every To move a position, the conversion matrix between the local world coordinate system and the world coordinate system at this position must be calculated, which increases the complexity of calibration to a certain extent.

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