CN111770263A

CN111770263A - Visual method for accurately capturing image of flowing product at specific visual angle

Info

Publication number: CN111770263A
Application number: CN202010443992.0A
Authority: CN
Inventors: 刘哲荣
Original assignee: Allied Automation Kunshan Co ltd
Current assignee: Allied Automation Kunshan Co ltd
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2020-10-13

Abstract

A visual method for accurately imaging a flowing product at a specific visual angle comprises the following steps: when the products transmitted on the conveying line pass through the image capturing position, the triggering block of the camera is triggered in advance, the camera continuously captures images according to the triggering time of the triggering block and the set frequency, and therefore at least one image which is closest to the optimal position of the products in the continuous images obtained by the camera is captured. The invention overcomes the product position deviation in the image capturing process at a specific unconventional angle, effectively obtains the optimal position of the product in the image and obtains a more accurate detection result.

Description

Visual method for accurately capturing image of flowing product at specific visual angle

Technical Field

The invention belongs to the technical field of conveying detection, and particularly relates to a visual method for accurately capturing images of a flowing product at a specific visual angle.

Background

Aiming at the inspection of a product in flow, a camera is adopted to match with a trigger sensor to trigger and photograph incoming materials in the conventional visual inspection. However, the trigger sensor may have unstable trigger time according to the difference of the material, shape or color of the surface of different measured objects, which may cause the difference of the image capturing time and indirectly cause the unstable measured position in the image capturing visual field. As shown in fig. 1, the image capturing position X of the theoretical product is different due to the variation of the trigger time caused by the communication time and the trigger stability. As shown in fig. 2, the image capturing position X' of the actual product is changed, so that there is an angle difference on the screen, which may result in failure of the inspection result in related applications.

At this time, the reference position can be corrected by using the feature location of the image processing method. However, when taking images at a specific angle, the deviation of the angle of view of the image will cause the deformation, enlargement or reduction of the detection area, which results in the distortion of the features used for positioning, and the correction cannot be performed by means of feature correction, so that the stability of the image-taking position in the screen becomes very important in the inspection application of products in motion.

Disclosure of Invention

The present invention provides a visual method for accurately capturing images of a flowing product at a specific viewing angle.

The purpose of the invention can be realized by the following technical scheme: a visual method for accurately imaging a flowing product at a specific visual angle comprises the following steps: when the products transmitted on the conveying line pass through the image capturing position, the triggering block of the camera is triggered in advance, and the camera continuously captures images according to the triggering time of the triggering block and the set frequency.

The trigger block of the camera is a virtual or entity trigger block; at least one of the continuous images obtained by the camera is closest to the optimal position of the product for image capture.

Compared with the prior art, the invention has the beneficial effects that: the product position deviation generated in the image capturing process at a specific unconventional angle is overcome, the optimal position of the product in the image is effectively obtained, and a more accurate detection result is obtained.

Drawings

Fig. 1 is a schematic diagram of image capturing positions of theoretical products in a conventional camera triggered image capturing method.

Fig. 2 is a schematic diagram of image capturing positions of an actual product in a conventional camera triggered image capturing method.

Fig. 3 is a schematic structural diagram of the vision method using the present invention.

FIG. 4 is a schematic structural diagram of an image capturing process using the vision method of the present invention.

Fig. 5 is a table showing the relationship between the number of images taken by the camera and the position of the product on the conveying line.

The parts in the figures are numbered as follows:

1 virtual or physical trigger Block

2, and (3) preparing the product.

Detailed Description

The following detailed description of the embodiments of the present invention will be given in conjunction with the accompanying drawings to make it clear to those skilled in the art how to practice the present invention. While the invention has been described in connection with preferred embodiments thereof, these embodiments are merely illustrative, and not restrictive, of the scope of the invention.

Referring to fig. 3 and 4, a visual method for accurately capturing images of a flowing product at a specific viewing angle, a camera is arranged at an image capturing position on a conveying line, and the camera is triggered by a virtual or solid trigger block 1 to capture images, and the method comprises the following steps: when a product 2 conveyed on a conveying line passes through an image capturing position, a virtual or entity triggering block 1 of a camera is triggered in advance, and the camera continuously captures images according to the triggering time of the virtual or entity triggering block 1 and the set frequency. The camera is continuously triggered in advance to capture images, so that continuous images are obtained, and the condition that one image is closest to the optimal position in the continuous images is guaranteed.

The best position for taking the image of the product is taken as the origin, and the image taken is taken as the best position. In this embodiment, the transmission speed of the conveyor line is 120mm/s, the image capturing frequency of the camera is 60fps, the deviation of the trigger time setting of the virtual or physical trigger block is-0.3 to 0.3s, the camera continuously captures 36 images, i.e. the front 18 images and the rear 18 images captured at the best position, as shown in fig. 5, and the actual condition is that the trigger time of the virtual or physical trigger block and the number of the continuous image capturing sheets of the camera are larger than the range. And finally, the deviation of the image taking position is controlled within 1mm, the deviation of the obtained visual angle image is smaller, and a more accurate detection result is obtained.

It should be noted that many variations and modifications of the embodiments of the present invention fully described are possible and are not to be considered as limited to the specific examples of the above embodiments. The above examples are given by way of illustration of the invention and are not intended to limit the invention. In conclusion, the scope of the present invention should include those changes or substitutions and modifications which are obvious to those of ordinary skill in the art.

Claims

1. A visual method for accurately imaging a flowing product at a specific viewing angle is characterized by comprising the following steps: when the products transmitted on the conveying line pass through the image capturing position, the triggering block of the camera is triggered in advance, and the camera continuously captures images according to the triggering time of the triggering block and the set frequency.

2. The visual method of claim 1, wherein the trigger block of the camera is a virtual or physical trigger block.

3. The visual method of claim 1, wherein at least one of the consecutive images obtained by the camera is captured closest to the optimal position of the product.