JPH05172525A - Method for detecting broken net in sieving machine - Google Patents

Abstract

PURPOSE:To obtain the reliable detecting method, wherein the problems of safety and sanitation are solved, by eliminating the defects in each conventional method for detecting the breaking of the nets in a sieving machine and the like for selecting rocks, ores and other materials. CONSTITUTION:Ores 1b and the like, which have passed through a net 2, are photographed. The image signals are sent into an image processing device 6. The sizes of the individual ore and the like are measured with the image processing device 6. The measured value obtained in this way is compared with a preset value in an operating device 8. When the measured value is larger than the preset value, it is judged that the net is broken, and the alarm is issued.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting breakage of a net such as a sieving machine for crushing ore, sieving plant or the like for sorting rocks, ores and other articles by size.

[0002]

2. Description of the Related Art A net such as a vibrating and sieving machine used for ore production or sorting according to the ore size in a receiving plant or the like sometimes breaks and a product larger than a required size is delivered. .. This naturally has an adverse effect on product quality, so breaking of the net must be detected early and countermeasures taken.

Conventionally, each of the following methods has been adopted as a method for detecting breakage of a net of a sieving machine or the like.

A. A person monitors the flowing state of ore or the like on a vibrating net from a remote place while a sieving machine is operating, visually or using an ITV camera or the like.

B. Humans visually inspect the screen while the sieving machine is stopped.

C. A person passes through a sieve based on ore under the net at regular intervals, and if there is some ore that does not pass, the net is judged to be broken.

[0007]

[Problems to be Solved by the Invention] The method (1) has drawbacks such as requiring labor and lack of certainty due to oversight.

The above b. The method (1) has the drawback that it cannot be detected during operation.

C. The method of (1) requires labor, lacks certainty due to oversight, and has problems in terms of health and safety.

The present invention solves the drawbacks of the above-mentioned methods for detecting the breakage of a net in a conventional sieving machine, and provides a detection method which is reliable and which also solves safety and health problems. It is an issue.

[0011]

According to the present invention, the above-mentioned problem is obtained by photographing rocks, ores, and other articles that have passed through a net using a photographing device, and transmitting an image signal from the photographing device to an image processing device. Send, measure the dimensions of individual rocks, ores, and other articles with this image processing device, compare the measured value thus obtained and the preset value with a computing device, When the measured value is large, it is solved by issuing an alarm output as if the network is broken.

[0012]

In the sorting by the sieving machine, the rocks, ores and other articles which pass through the net and are transferred by the belt are photographed by the photographing device such as the ITV monitoring camera. next,
The dimensions of individual rocks, ores, and other objects in the photographed screen are measured by an image processing device. The size of the largest stone, article or the like that can pass when the net is not broken is set in advance, and this set value is compared with the above-mentioned measured value. When rocks, ores, or other articles exceeding the above set values are found, it is judged that the net has been broken and an alarm is output.

[0013]

EXAMPLE An example in which the present invention is applied to the detection of mesh breakage of a vibration sieving machine for crushed rocks, ores, etc. (hereinafter referred to as stones) will be described below with reference to the drawings.
The present invention is not limited to this.

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-net discharging 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 size of each stone measured by the image processing device 6 is compared with the size preset by the setting value input 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. The setting value input may be set by a person in advance, or the setting may be changed by the arithmetic unit 8 itself by some learning function.

An example of a method for measuring the dimensions of the above-mentioned article by the image processing apparatus 6 will be shown below.

Example 1 On the display screen 7a of the image monitor 7 shown in FIG. 2, images A, B, C and D of several stones on the under-mesh discharge conveyor 4 are displayed. Only the image A of the stone is shown in FIG. As shown in FIG. 3, the stone image A is divided into pixels 10, and the number of pixels 10 in the region of the stone image A is counted to calculate a measurement value as an area, and the measurement value is calculated as The size. This measurement of the size of the other stone images B, C, D
Also do.

Example 2 Of the stone images A, B, C and D displayed on the display screen 7a of the image monitor 7 shown in FIG. 2, only the stone image A is shown in FIG.
Is shown in.

In FIG. 4, the image processing device 6 obtains a straight line 11 giving the maximum length of the stone image A, and then an arbitrary number of perpendicular lines 12, 1 to the straight line 11 giving the maximum length.
3 and 14 are drawn, and the lengths of these perpendiculars intersecting the stone image A are individually calculated, and the perpendicular 14 having the maximum length is selected. The length of the perpendicular line 14 thus selected is the size of the stone displayed as the stone image A. This dimension measurement is also performed on the images B, C, and D of other stones.

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

Example 3 Of the stone images A, B, C and D displayed on the display screen 7a of the image monitor 7 shown in FIG. 2, only the stone image A is shown in FIG.
Shown in.

In FIG. 5, the image processing apparatus 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 across the stone image A are individually calculated. The maximum vertical line 23 is selected from the vertical lines whose lengths have been calculated in this way, and the length of the vertical line 23 is taken as the size of the stone displayed as the stone image A. This dimension measurement is also performed on the images B, C, and D of other stones.

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

Example 4 Of the stone images A, B, C and D displayed on the display screen 7a of the image monitor 7 shown in FIG. 2, only the stone image A is shown in FIG.
Shown in.

In FIG. 6, the image processing apparatus 6 deletes a stone image A on the display screen 7a of the image monitor 7 with a predetermined width t, for example, a width corresponding to 10 mm, and a new stone image A is displayed. Get ' Image A'of this newly obtained stone
Is again deleted with the same width t to obtain a new stone image A ″. This operation is repeated, and the image of the minimum stone is obtained by repeating N−1 deletions, and disappears by the Nth deletion. In this case, the number of times N is the size of the stone, and this size measurement is performed on the images B, C, and D of the other stones.

The value of the deletion width t can be appropriately determined according to the size, shape, distribution state, etc. of the stone image.

Example 5 Of the stone images A, B, C and D displayed on the display screen 7a of the image monitor 7 shown in FIG. 2, only the stone image A is shown in FIG.
Shown in.

In FIG. 7, the image processing device 6 selects an arbitrary number of points P1, P2, P3 in the image A of the stone shown on the display screen 7a of the image monitor 7, and then the points P1,
An arbitrary number of straight lines P1-1, P1-2 passing through P2, P3,
... P2-1, P2-2, ... P3-1, P3-2, ...
…pull. For each of these straight lines, the length across the stone image A is calculated, and the shortest straight lines P1-2, P2-2,
Find P3-1 and use these as the width at each of the points. The straight line P1-2 having the maximum width is selected from the widths at the respective points thus obtained, and the value of the length thereof is taken as the size of the stone. This dimension measurement is also performed on the images B, C, and D of other stones.

The number of points and the number of straight lines at each point can be appropriately determined according to the size, shape, distribution state of the stone image.

[0031]

Industrial Applicability According to the present invention, it is ensured that the screen of the sieving machine for sorting rocks, ores, and other articles in size is broken in the control of production, reception, etc. of rocks, ores, and other articles. And since it can be detected promptly, it is possible to prevent unnecessary troubles. Furthermore, by appropriately selecting the lens of the image capturing device, the distance between the image capturing device and the target rock, ore, or other object can be increased, which may cause a problem such as failure due to wear of the detection device. No, its industrial value is enormous.

[Brief description of drawings]

FIG. 1 is an explanatory view of an apparatus for carrying out a detection method according to the present invention.

FIG. 2 shows a display screen of an image monitor that displays rocks, ores, etc. on a below-mesh discharge conveyor.

FIG. 3 is an explanatory view of an embodiment of an article dimension measuring method.

FIG. 4 is an explanatory view of another embodiment of the method for measuring the dimension of an article.

FIG. 5 is an explanatory diagram of yet another embodiment of the method for measuring the dimension of an article.

FIG. 6 is an explanatory diagram of still another embodiment of the method for measuring the dimension of an article.

FIG. 7 is an explanatory diagram of still another embodiment of the method for measuring the dimension of an article.

[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 computing device 9 alarm device A, B, C, D stone image

Claims (1)

[Claims] 1. A method of detecting breakage of a net such as a sieving machine for sorting rocks, ores, and other items by size, using a photographing device for the rocks, ores, and other items that have passed through the net. The image signal from the image capturing device is sent to the image processing device, and the dimensions of individual rocks, ores, and other articles are measured by this image processing device, and the measurement values thus obtained are set in advance. A method for detecting network breakage of a sieving machine, which compares the set value with an arithmetic device and issues an alarm output when the measured value is larger than the set value.