JP2017032346A - Monitoring system of belt conveyor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitoring system of a belt conveyor, which can automatically determine whether or not a detected damaged part requires maintenance.SOLUTION: A system for monitoring abnormality of a belt conveyer includes at least: a line laser for irradiating the belt conveyer with a laser beam; a digital camera for imaging a contour line which is drawn on the belt conveyer by the irradiation with the laser beam at an angle different from an irradiation direction of the line laser; and an analysis device for determining a degree of damage of the belt on the basis of image data by the digital camera.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a system for monitoring an abnormality of a belt conveyor, and more particularly to a system for detecting damage of a belt conveyor and determining whether maintenance is necessary due to the damage.

In tunnel excavation work, long-distance belt conveyors are used for shearing.
At this time, the belt may be damaged by meandering, slipping, foreign matter, or the like of the belt. If these damages are left unattended, belt breaks and spills will occur, and the operating rate of the belt conveyor will be greatly reduced due to the repair.
Therefore, it is necessary to detect such signs early and perform preventive maintenance.

As a belt conveyor monitoring system, the applicant has previously developed a system described in Patent Document 1 below.
This monitoring system uses the marker provided on the belt as a reference to calculate the belt length from the marker to the damaged part, thereby identifying the position of the damaged part and irradiating the belt surface with light to shade the damaged part. It is a system that aims to improve the detection accuracy of the damaged part by detecting.

Japanese Patent No. 5599671

  In the monitoring system described in the cited document 1, the presence or absence of a damaged part and the position of the damaged part can be detected. If it can be determined whether or not the damaged part requires immediate maintenance, further convenience can be expected.

  It is an object of the present invention to automatically determine whether or not a detected damaged portion requires maintenance.

The first invention of the present application to solve the above-mentioned problems is a system for monitoring abnormality of a belt conveyor, which irradiates a laser beam to the belt conveyor, and the irradiation of the laser beam. A contour line drawn on the belt conveyor by a digital camera, and a digital camera, and an analysis device for determining a degree of belt damage based on photographing data by the digital camera; And at least.
Further, according to a second invention of the present application, in the first invention, the analysis device generates damage data including at least a position, a size and a depth of a belt scratch from the imaging data, And determining means for notifying an alarm when damage data satisfies a predetermined condition.
It is characterized by that.
According to a third invention of the present application, in the second invention, the detection means transmits only damage data satisfying a certain condition among the generated damage data to the determination means.

According to the present invention, the following effects can be obtained.
(1) The state of the damaged part can be grasped with high accuracy.
In the present invention, the resolution accuracy of the calculation of the cross-sectional area of the conveyed object is determined by the resolution of the camera. For example, assuming that the width of the belt conveyor is 1 m and the number of pixels of the digital camera is 10 million pixels, the length per pixel can be ensured to be 1 mm or less. Therefore, it becomes possible to grasp the state of the damaged portion with higher accuracy than the conventional method.
(2) A reduction in the operating rate of the belt conveyor can be suppressed.
Whether or not maintenance is necessary can be automatically determined while maintaining the state in which the belt conveyor is operated. Therefore, it is not necessary to stop the belt conveyor excessively.
(3) The determination accuracy is stable.
Since the damaged portion is image-processed and the state (size / depth) of the damaged portion is quantified, the accuracy of determining whether or not the scratch requires maintenance is stabilized.
(4) Load control of determination processing is possible.
By transmitting only damage data satisfying a certain condition to the determination means, the detection means can narrow down the damage data to be subjected to determination processing by the determination means to the minimum necessary range, and the load on the determination means Can be suppressed.

1 is a schematic configuration diagram of a monitoring system according to a first embodiment of the present invention. Cross section of belt showing the locus of the contour line by laser light irradiation Conceptual diagram when generating damage data from image data Flow chart showing an example of determination processing based on damage data (1) Flow chart showing an example of determination processing based on damage data (2) The schematic block diagram of the monitoring system which concerns on 2nd Example of this invention. Schematic configuration diagram of a monitoring system according to a third embodiment of the present invention.

  Embodiments of a monitoring system according to the present invention will be described below with reference to the drawings.

<1> Overall Configuration FIG. 1 is a schematic configuration diagram showing a first embodiment of a monitoring system according to the present invention.
The monitoring system according to the present invention is a system that is installed on a belt conveyor A that conveys the object to be conveyed X.
The monitoring system according to the present embodiment includes at least a line laser 10, a digital camera 20, and an analysis device 30.
Details of each component will be described below.

<2> Line Laser The line laser 10 is a device for drawing the contour line 12 on the surface of the belt A1 of the belt conveyor A.
In the present embodiment, the line laser 10 is provided below the belt conveyor A, and is arranged so as to irradiate the laser beam 11 to the belt A1 on the return path side of the belt conveyor A.
The irradiation direction θ1 of the laser beam 11 is appropriately determined in the range of 0 ° <θ1 <180 ° when the horizontal direction is 0 ° (180 °).
In this embodiment, the irradiation direction of the laser beam 11 is set to the vertical direction (90 °).
The laser beam 11 may be constantly irradiated, or may be irradiated only when the digital camera 20 is photographing.

<2.1> Example of Contour Line FIG. 2 shows a trajectory of a contour line by laser light irradiation.
First, a laser beam 11 is irradiated in a substantially vertical direction from a line laser 10 provided below the belt A1 on the return path side of the belt conveyor A.
A contour line 12 is drawn on the surface of the belt A1 by the irradiated laser beam 11.
If the locus of the contour line 12 deviates from the locus of the contour line when the laser beam 11 is irradiated to an undamaged belt A1 (normal locus), the belt is damaged (hereinafter simply referred to as “ It can be seen that this state is also referred to as “scratch A2” (FIG. 2A).
When the scratch A2 passes through the belt A1, the laser beam 11 passes through the penetrating portion, so that the contour line 12 is drawn as if it was divided at that location (FIG. 2B).
The normal trajectory described above can be registered in advance in the analysis device 30 described later.

<2.2> Formation of light-shielding part In addition, it is preferable to place the irradiated part in a light-shielded state so that the irradiated part of the laser beam 11 on the belt A1 does not interfere with other light sources such as a lighting device and sunlight.

<3> Digital Camera Refer to FIG. 1 again.
The digital camera 20 is a device for photographing the contour line 12 drawn on the surface of the belt A1.
The digital camera 20 captures images from an angle different from the irradiation direction of the line laser 10 from the side where the line laser 10 is located.
The larger the number of pixels of the digital camera 20, the better in terms of improving the accuracy of image analysis. However, since the analysis time also becomes longer, it may be determined within an appropriate range.

<4> Analysis Device The analysis device 30 is a device for determining damage to the belt conveyor A.
The analysis device 30 can be realized by hardware or software constituting an information processing device such as a PC, or a combination thereof.

<4.1> Function of Analysis Device The analysis device 30 has a function of generating damage data based on image data captured by the digital camera 20 and notifying an alarm when the damage data satisfies a predetermined condition. Have.
The information processing by the analysis device 30 may be configured to acquire shooting data in real time from the digital camera 20 and determine while calculating damage data as needed, or after storing the shooting data in a certain range, You may comprise so that the damage data of an accumulation | storage part may be calculated and determined collectively.

<4.2> Damage data Damage data is information indicating the state of a damaged part.
In this embodiment, the damage data is composed of information such as the location of the flaw, the size of the flaw, the depth of the flaw, and the presence or absence of penetration.
By applying this damage data information to the determination conditions, it is determined whether maintenance is necessary.

<4.3> Specific Example of Analysis Device The analysis device 30 can be configured to include at least the following two means (detection means 31 and determination means 32) in order to realize the above-described function or configuration. .
The following means may be realized by hardware or software constituting an information processing apparatus such as a PC, or a combination thereof.

<4.3.1> Detection Unit The detection unit 31 is a unit for generating the damage data from the photographing data.
More specifically, first, the detection unit 31 performs image processing such as integration processing on the shooting data based on the relationship between the angle between the shooting direction of the digital camera 20 and the irradiation direction of the line laser 10 to obtain a two-dimensional or Generate a 3D flaw shape diagram.
The damage data is calculated from the data of this shape diagram.
Of the damage data, the size and depth of the scratch A2 may be values quantified from the scratch shape diagram.

<4.3.1.1> Example of Damage Data Generation An example of damage data generation method by the detection means 31 will be described below.
[1] Specific example of flaw location in the width direction of the belt Referring to FIG. 2 again.
The location of the scratch A2 in the width direction of the belt A1 becomes clear from the above-described photographing data. As shown in FIG. 2, the vicinity of the center of the photographing data corresponds to the vicinity of the center in the width direction of the belt A1, and if there are scratches on the left and right ends of the photographing data, it corresponds to the ear side in the width direction of the conveyor. .
As described above, it is possible to specify whether the wound is on the central side or the ear side of the belt based on the photographing data.

[2] Example of Quantifying Scratch Size As a method of quantifying the size of the scratch A2, for example, the shape of the scratch is replaced with a shape (circular, elliptical, polygonal) that approximates the scratch A2. There is a method in which the length of the longest straight line (the diameter in a circle, the long axis in an ellipse, the diagonal in a quadrangle, etc.) is used as the size of the scratch after the replacement.
FIG. 3A shows a planar shape of the scratch A2.
The scratch A2 is replaced with an ellipse (approximate shape A3) that approximates the shape of the scratch A2, and the length of the long axis of the approximate shape A3 is quantified as the size L of the scratch.

[3] Example of Quantification of Scratch Depth As a method of quantifying the depth of the scratch A2, for example, there is a method of obtaining by analyzing imaging data.
FIG. 3B shows a cross-sectional shape of the scratch A2.
In FIG. 3B, the distance from the surface of the belt to the deepest part in the scratch portion in the photographing data is quantified as the scratch depth H.
In addition, when the damage | wound has penetrated the belt, the depth of a damage | wound cannot be guide | induced.

<4.3.1.2> Transmission of Damage Data Damage data generated by the detection unit 31 is transmitted to the determination unit 32 described later.
At this time, all of the damage data may be transmitted to the determination unit 32, or the detection unit 31 may be configured such that scratches less than a predetermined size are filtered in advance and not transmitted to the determination unit 32. .

<4.3.2> Determination Unit The determination unit 32 is a unit for acquiring damage data generated by the detection unit 31 and notifying an alarm when the damage data satisfies a predetermined condition.
An example of conditional branching used in the damage data determination method by the detection means 32 will be described below with reference to the flowcharts shown in FIGS.

[1] Conditional branching based on the location of the scratch (S100)
Conditional branching can be made depending on whether or not the location of the wound A2 is in the ear portion of the belt A1.
This is because when the scratch A2 is on the ear, the scratch A2 hits the side frame (not shown) of the belt conveyor A and grows easily. It is to do.

[2] Conditional branching based on the presence or absence of scratch penetration (S200, S210)
Conditional branching can be made depending on whether or not the wound A2 penetrates the belt A1.
This is because the condition determination based on the depth H of the scratch cannot be used thereafter when the scratch A2 penetrates the belt A1.

[3] Conditional branching based on flaw depth (S310, S320)
Conditional branching can be made depending on whether or not the depth H of the scratch exceeds a certain threshold (T).
This is because the threshold value of the scratch size L, which will be described later, may be changed depending on the scratch depth H.

[4] Conditional branching based on the size of the scratch (S300, S400 to S430)
Conditional branching can be performed depending on whether or not the size L of the scratch exceeds a certain threshold (B1 to B6).
This is because, depending on the size L of the scratch, it is determined whether to notify the alarm because maintenance is required or to maintain the current state (leave).

As described above, the monitoring system according to the present invention includes at least the line laser 10, the digital camera 20, and the analysis device 30, so that the state of the scratch on the belt A1 can be grasped with high accuracy.
Further, since the necessity of maintenance can be determined while maintaining the state in which the belt conveyor A is operated, the operation rate of the belt conveyor A is not unduly lowered.

<5> Other devices The monitoring system according to the present invention can also include the following devices.
<5.1> Movement Amount Sensor The movement amount sensor 40 is a device that can detect the movement amount (conveyance speed) of the belt conveyor A.
A known member may be used for the movement amount sensor 40, and detailed description thereof is omitted.
If the movement amount (conveyance speed) of the belt conveyor A by the movement amount sensor 40 can be grasped, it is possible to specify the length of the flaw on the conveyance direction side together with the photographing interval of the digital camera 20.
Further, in combination with the marker described in Patent Document 1, it is possible to specify the position of the flaw on the conveyance direction side of the belt A1.

<5.2> Notification Unit The notification unit is a device for displaying an alarm notified from the analysis device 30.
As the notification means, a display connected to the analysis device 30 can be used although not shown.

FIG. 6 shows a schematic configuration diagram of a monitoring system according to the second embodiment.
In the present embodiment, a cleaning device 50 for the belt A1 is provided in front of the portion where the line laser 10 is irradiated. A scraper or the like can be used for the cleaning device 50.
According to the present embodiment, it is possible to prevent problems such as the presence or absence of scratches and misrecognition of the shape due to adhesion of the remainder of the conveyed object X to the belt A1.

In FIG. 7, the schematic block diagram of the monitoring system which concerns on 3rd Example is shown.
In the present embodiment, a belt bending prevention mechanism 60 is provided in the vicinity of the portion irradiated with the line laser 10. For this bend prevention mechanism 60, a frame or the like that supports the belt A1 on the return path can be used.
According to the present embodiment, it is possible to eliminate the influence of the measurement error due to the deflection of the belt A1.

The monitoring system according to the present invention may be configured such that the line laser 10 and the digital camera 20 are provided above the belt conveyor A, and a scratch on the belt A1 is detected on the forward path side of the belt conveyor A (not shown). .
According to the present embodiment, the detection accuracy of the scratch A2 is poor in the state where the conveyed object X is being carried out by the belt conveyor A, but if the belt conveyor A is in an idling state, it is equivalent to the above-described embodiment. The detection accuracy can be maintained.
Similarly, in the monitoring system shown in the first to third embodiments, the line laser 10 and the digital camera 20 are provided below the belt conveyor A to detect a scratch on the belt A1 on the return path side. It is not limited to the configuration.

A Belt Conveyor A1 Belt A2 Scratch X Conveyed Object L Scratch Size H Scratch Depth 10 Line Laser 11 Laser Light 12 Contour 20 Digital Camera 30 Analyzing Device 31 Detecting Device 32 Judging Device 40 Moving Amount Sensor 50 Cleaning Device 60 Deflection prevention mechanism

Claims (3)

A system for monitoring an abnormality of a belt conveyor,
A line laser that irradiates the belt conveyor with laser light;
A digital camera that captures an image of a contour drawn on a belt conveyor by irradiation of the laser light from an angle different from the irradiation direction of the line laser;
An analysis device that determines the degree of damage to the belt based on data captured by the digital camera;
Comprising at least
Belt conveyor monitoring system. The analysis device includes:
Detecting means for generating damage data including at least a position, a size and a depth of a wound on the belt from the photographing data;
A determination means for notifying an alarm when the damage data satisfies a predetermined condition; and
Having at least
The belt conveyor monitoring system according to claim 1.   The belt conveyor monitoring system according to claim 2, wherein the detection means transmits only damage data satisfying a certain condition among the generated damage data to the determination means.

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