JPH05172527A - Method for measuring size of material - Google Patents

Abstract

PURPOSE:To obtain the method for measuring the size of a material when the sizes are controlled in the production, shipment, acceptance and the like of rocks, ores and other materials. CONSTITUTION:A material is photographed by using a photographing device. A curve 20, which represents the skeleton of the material is extracted for every image of the material with an image processing device based on the image signal from the photographing device. Arbitrary numbers of perpendiculars 21, 22, 23 and 24 are drawn with respect to the obtained curve 20 representing the skeleton. The length of each perpendicular, which crosses the image of the material, is individually computed. The length of the longest perpendicular 23 among them is made to be the size of the material, and the size is outputted for every material.

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 dimensions of rocks, ores, and other articles in the case of performing dimension 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 according to the dimensions. 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 if this size exceeds the set value, take measures as the breakage of the net. 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]

SUMMARY OF THE INVENTION Method a. Has the drawback of low reproducibility and large error 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. Is unsuitable for inspection and replacement of mechanical vibrating screens because it has little correlation with mechanical vibrating screens depending on the shape of the article.

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

[0009]

According to the present invention, an object is photographed by a photographing device, and an image signal from the photographing device is sent to an image processing device. Extract a curve representing the skeleton for each image of, and draw an arbitrary number of perpendiculars to the obtained curve representing the skeleton, calculate the length of each perpendicular crossing the image of the article individually, and calculate the length of the longest perpendicular 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 on the curve representing the skeleton, and the length of the perpendiculars crossing the image of the article is determined. It is calculated individually, and the vertical line having 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]

DETAILED 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 according to 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 stones 1b smaller than the mesh openings pass through the mesh and under the mesh discharge conveyor 4 It drops down and is discharged.

The stone 1b on the under-mesh discharge conveyor 4 is an ITV.
An image is taken by the image taking device 5 such as a surveillance camera or a video camera, and the signal is sent to the 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 device in the arithmetic unit 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 A, B of several stones on the net discharge conveyor 4 are
C and D are displayed. Of these, only the image A of the stone is shown in FIG. 3 to describe the dimension measuring method in the image processing apparatus 6, but the images B, C and D of the other stones displayed on the display screen 7a are also described. The size is measured for each image.

In FIG. 3, the image processing apparatus 6 obtains a curve 20 representing the skeleton of the stone image A, and then an arbitrary number of perpendiculars 21, 22, 2 to the curve 20 representing this skeleton.
3 and 24 are drawn, the lengths of these perpendiculars crossing the stone image A are individually calculated, and the vertical line 23 of the maximum length is selected, and the length of this vertical line 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 depending on the size, shape, distribution state, etc. of the stone image.

[0018]

EFFECTS OF THE INVENTION 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 is 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.

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

FIG. 3 is an explanatory view 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 curve 21 representing the skeleton of the stone image 21, 22, 23, 24 for curve 20 Image of arbitrary number of perpendiculars A, B, C, D stones

Claims (1)

[Claims] 1. A method for measuring the dimensions of an article in the case of 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 among them is output as the dimension of the article, and the dimension is measured for each article.