Illuminating device and imaging method for visual inspection of defects on outer surface of steel pipe

Abstract

A lighting device for visual inspection of defects on the outer surface of a steel pipe comprises a lamp shell and a lampshade which are concentrically arranged, the lampshade is located in the lamp shell, connected side plates are arranged between the lamp shell and the lampshade, and the side plates are located on the two opposite sides of the lamp shell and the lampshade; a plurality of circumferentially arranged LED lamp strips are arranged on the inner wall of the lamp shell, and the LED lamp strips are arranged towards the lampshade; the lampshade is made of transparent materials, and a light uniformizing film is attached to the outer surface of the lampshade. A driving controller electrically connected with the LED lamp strips is arranged outside the lamp shell, and the driving controller synchronously controls all the LED lamp strips. Opposite lamp shell brackets are arranged on the outer wall of the lamp shell; compared with the prior art, when the camera obliquely faces the inner side of the barrel lamp, the object space corresponding to the imaging surface of the camera sensor is the inner wall, uniformly emitting light, of the barrel lamp, so that stray light generated by reflection cannot be introduced, and the pixel difference on the plane of the sensor is only caused by different surface shapes and roughness of the surface of a steel pipe; therefore, 360-degree uniform illumination imaging on the surface of the high-reflection steel pipe can be realized.

Description

technical field [0001] The invention relates to the technical field of visual defect detection thereof, in particular to an illumination device and an imaging method for visual detection of defects on the outer surface of steel pipes. Background technique [0002] The visual detection of surface defects of steel pipes is an indispensable process before the steel pipes leave the factory. With the rapid development of machine vision in recent years and its popularization and application in the industrial field, the visual detection of surface defects of steel pipes has also begun to change from manual to computer automatic. Recognize the direction change. The automatic recognition of steel pipe outer surface defects can be mainly divided into two methods according to different sensors, one is three-dimensional surface recognition based on line-scanning laser sensors, and the other is two-dimensional image recognition based on industrial cameras. The former usually comes with ...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the defects in the above-mentioned prior art, and provide a barrel-shaped 360° uniform illumination, which can effectively solve the problems caused by the uneven illumination of the traditional light source on the steel pipe and the imaging of the oblique illumination, which is used for the defects of the outer surface of the steel pipe. Illumination device and imaging method for visual inspection

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