JPH0820216B2 - Article dimension measurement method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the size of rocks, ores, and other articles in the case of performing size control such as production, shipping and acceptance.

[0002]

2. Description of the Related Art For example, when shipping or receiving rocks, ores, and other articles, it is necessary to confirm whether or not they have predetermined dimensions, or to select a sieving machine for sorting ores or the like. In order to detect the breakage of the net, it is necessary to measure the size of the ore or the like that has passed through the net and take measures against the breakage of the net when this size exceeds a set value. For such dimension management,
Conventionally, the following measures have been taken as a method for measuring the dimensions of an article.

A. A method in which a person visually monitors b. Method of inferring dimensions from the sound of an article hitting an iron plate c. A method of actually sorting articles using a mechanical vibrating screen d. Method of measuring maximum length, area, etc. by image processing

[0004]

The above-mentioned method a. Has the drawbacks of low reproducibility and large errors due to fatigue.

Method b. Is a large error, noise is generated, failure due to wear, etc.
There are drawbacks such as the possibility of damage to the article.

Method c. Is a measurement time,
There are drawbacks such as failure due to wear.

The above method d. However, depending on the shape of the article, the correlation with the mechanical vibration sieve is small, and is not suitable for the inspection or replacement of the mechanical vibration sieve.

An object of the present invention is to provide a measuring method which eliminates the above-mentioned drawbacks in the conventional dimension measuring method for articles.

[0009]

According to the present invention, an object is photographed by a photographing device, an image signal from the photographing device is sent to an image processing device, and the image processing device uses the image signal. Extract the curve representing the skeleton for each image of, and draw an arbitrary number of perpendicular lines to the obtained curve representing the skeleton, calculate the length of each perpendicular line across the image of the article individually, and calculate the longest perpendicular line of them. This is solved by outputting the length as the dimension of the article for each article.

[0010]

The curve representing the skeleton of the image of the article displayed on the display screen of the image monitor is obtained, and an arbitrary number of perpendiculars are drawn to the curve representing the skeleton, and the perpendiculars cross the image of the article. It is calculated individually, and the vertical line with the maximum length is selected, and the length of this vertical line is taken as the dimension of the article. This dimension measurement is also performed on images of other articles displayed on the display screen of the image monitor.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings show an example in which the present invention is applied to detect the breakage of the net of a sieving machine for sorting by the size of ore or the like (hereinafter referred to as stone). Hereinafter, the present invention will be described with reference to these drawings, but the present invention is not limited thereto.

In FIG. 1, a stone 1 carried out from a crusher (not shown) or other processing device falls on a net 2 of a sieving machine, and is subjected to size selection by the net 2. Stones 1a larger than the mesh openings fall on the mesh discharge conveyor 3 without passing through the mesh and are discharged, and stones 1b smaller than the mesh opening pass through the mesh and the mesh discharge conveyor 4 under the mesh. It drops down and is discharged.

The stone 1b on the under-net discharging conveyor 4 is an ITV.
An image is taken by a photographing device 5 such as a surveillance camera or a video camera, and the signal is sent to an image processing device 6, where the size of each stone is measured. An image monitor 7 for inspection and adjustment can be installed in the image processing device 6. The image monitor 7 can be used not only for inspection and adjustment but also for monitoring stones on the under-the-mesh discharge conveyor 4 if necessary. 7a is a display screen of the image monitor 7.

The dimensions of the individual stones measured by the image processing device 6 are compared with the dimensions preset by the setting value input in the arithmetic device 8. If there is a stone larger than the preset size, it is determined that the net 2 has been broken and a signal is sent to the alarm device 9 to issue an alarm. In addition,
The setting value may be set by a person in advance, or the setting may be changed by the arithmetic unit 8 itself by some learning function.

A display screen 7a of the image monitor 7 shown in FIG.
The images of several stones A, B,
C and D are displayed. Of these, only the image A of stones is shown in FIG. 3 to describe the method of measuring the dimensions in the image processing apparatus 6, but the images B, C and D of other stones displayed on the display screen 7a are also described. The size is measured for each image.

In FIG. 3, the image processing device 6 obtains a curve 20 representing the skeleton of the stone image A, and then an arbitrary number of perpendicular lines 21, 22, 2 are added to the curve 20 representing this skeleton.
3 and 24 are drawn, and the lengths of these perpendiculars crossing the stone image A are calculated individually, and the perpendicular 23 having the maximum length is selected, and the length of the perpendicular 23 is displayed as the stone image A. Dimensions. This size measurement is performed on the image B of another stone,
This is also done for C and D.

The number of perpendicular lines can be appropriately determined according to the size, shape, distribution state, etc. of the stone image.

[0018]

Since the method for measuring the size of an article according to the present invention is non-contact, there is no abrasion of the contact portion with the article or damage to the article, and even if the article has an irregular shape such as ore, The dimensions can be measured reliably. Therefore, it has a large correlation with the mechanical vibrating screen and is suitable for inspection and replacement of the vibrating screen.

Further, in detecting the breakage of the net such as a sieving machine for sorting by size, the measured value obtained as described above and the maximum value that can be passed when the preset net is not broken. The size of the article is compared, and when the measured value is larger than the set value, it is possible to output an alarm that the net has broken. Furthermore, it is possible to control the mechanical settings of the crusher, which has great industrial value.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a network breakage detection device of a sieving machine to which the detection method according to the present invention is applied.

FIG. 2 is a display screen of an image monitor of the apparatus shown in FIG.

FIG. 3 is an explanatory diagram of a stone size detecting method according to the present invention.

[Explanation of symbols]

1 stone 1a stone that did not pass through the net 1b stone that passed through the net 2 net 5 shooting device 6 image processing device 8 arithmetic unit 9 alarm device 20 curves 21, 22, 23, 24 representing the skeleton of the stone image Image of arbitrary number of perpendiculars A, B, C, D stones

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location // B65G 43/08 F (56) Reference JP-A-61-117667 (JP, A) JP Hei 1-245371 (JP, A) JP 63-247882 (JP, A) JP 60-204084 (JP, A) JP 57-87280 (JP, A) JP 60-218011 (JP , A) JP-A-3-195908 (JP, A) JP-A-5-172525 (JP, A)

Claims (1)

[Claims] 1. A method for measuring a dimension of an article when performing dimension management such as production, shipping, and acceptance of the article, wherein the article is photographed by using a photographing device, and an image signal from the photographing device is sent to an image processing device. With this image processing device, a curve representing a skeleton is extracted for each image of an article, an arbitrary number of perpendicular lines are drawn on the obtained curve representing the skeleton, and the length of each perpendicular line crossing the image of the article is individually calculated. Then, the length of the longest perpendicular line is output as the dimension of the article, and the dimension is measured for each article.