Fast calibration method of multiple line structured light visual sensor

Abstract

The invention belongs to the technical field of visual detection, and provides a calibration method which is convenient and fast to use and accurate. The fast calibration method aims to make full use of characteristics of the multiple line structured light visual sensor in the aspect of three-dimensional shape measurement so as to be applied to on-line three-dimensional detection of industrial products. According to the technical scheme, the fast calibration method of the multiple line structured light visual sensor comprises the steps that a three-dimensional measurement model of the multiple line structured light visual sensor is built, wherein a measurement coordinate system is set in a world coordinate system where virtual space feature points are calibrated through the three-dimensional measurement model; according to the measurement model, due to the adoption of the Zhang calibration method that visual angles are not determined, a plurality of coplanar positions are placed through the visual sensor (namely, a plane target) to acquire virtual space feature point arrays so as to carry out camera calibration; three-dimensional point arrays on each light plane are acquired according to camera calibration results and the cross ration invariability theory to finish light plane calibration; the three-dimensional shape of a measured object is worked out in a back calculation mode through the measurement model. The fast calibration method of the multiple line structured light visual sensor is mainly used for visual detection.

Description

technical field [0001] The invention belongs to the technical field of visual detection, and in particular relates to a fast calibration method for a multi-line structured light visual sensor. technical background [0002] Structured light three-dimensional visual measurement technology has the advantages of non-contact visual measurement, high speed, high degree of automation, and good flexibility. Structured light 3D vision is based on the principle of optical triangulation, and calculates the surface profile of the measured object by calculating the offset information of various light mode feature points in the collected image. The optical projector projects a certain light pattern, which makes the structured light image information easy to extract, so the measurement accuracy is high, and it is widely used in the online detection of various industrial products. [0003] Typical structured light modes include point structured light, line structured light and multi-line s...

AI Technical Summary

Problems solved by technology

However, the multi-light bar mode introduces the complexity of calibration and the problem of light bar matching at the same time.

System calibration, especially optical plane calibration, requires accurate three-dimensional feature points. There are many ways to establish a three-dimensional feature point array: three-dimensional targets can be used to establish, but three-dimensional targets are difficult to process, high cost, and difficult to guarantee accuracy; measurement equipment (such as theodolite or precision translation stage) to determine the three-dimensional coordinates of feature points, but this method is more complicated and inefficient

These constraints limit the application of multi-line structured light mode in

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