JP2002139312A - Measuring method of earth-carrying quantity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve measurement accuracy. SOLUTION: The contour of carrying sediment on a conveyor is photographed in a fixed position, the cross-sectional area of the carrying sediment for each prescribed time is arithmetically operated by image processing, and a carrying earth quantity for each prescribed time is arithmetically operated, by multiplying the obtained cross-sectional area with a carrying speed of the conveyor to measure the carrying earth quantity of the conveyor for determining an integral value of the obtained carrying earth quantity. Before actually measuring the carrying sediment A, plural planar models M1 to M4 different in a contour shape having known cross-sectional area are premanufactured; the respective planar models M1 to M4 are photographed under the same condition as actual measurement; the operational cross-sectional areas sm1 to sm4 with respective plane models M1 to M4 are determined by the image processing, a correction reference is made on the basis of these operational cross-sectional areas sm1 to sm4 the known cross-sectional areas s1 to s4; and when actually measuring the carrying sediment A, the actually measured cross-sectional area s is corrected on the basis of the correction reference.

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 amount of soil transported, and more particularly to a technique for measuring the amount of earth and sand being transported on a belt conveyor, in which the measurement accuracy is improved.

[0002]

2. Description of the Related Art When transporting earth and sand on a conveyor, an apparatus for measuring the amount of soil transported is disclosed in, for example, JP-A-2-12440.
No. 9 discloses that the planar shape of earth and sand conveyed continuously on a conveyor is continuously photographed from another position by an imaging device,
There has been proposed an apparatus for continuously measuring the amount of conveyed soil from the obtained planar imaging information and the conveyor speed.

[0003] The apparatus disclosed in this publication includes an image pickup means for picking up an image of a contour of soil conveyed on a conveyor at a fixed position, a speed detecting means for detecting a convey speed of the conveyer, and a device based on the imaged contour. Image processing means for calculating the cross-sectional area of the conveyed soil per unit time, calculating means for calculating the soil volume per unit time by multiplying the obtained cross-sectional area by the conveying speed, and the obtained unit soil An integrating means for sequentially integrating the amounts and a display means for recording and displaying the integrated value are provided.

[0004] The apparatus disclosed in this publication has the advantages that continuous measurement of the amount of sediment conveyed is possible, the apparatus configuration is simple, and the installation is easy. There were also issues.

[0005]

That is, in the measuring device disclosed in the above-mentioned publication, the conveyed earth and sand on the conveyor is photographed obliquely from above by the imaging means. And the center of the imaging screen.

However, in the contour photographing in such a state, the horizontal direction is wider than the actual position above the center of the image screen, and the vertical direction is narrower than the actual position.

[0007] Further, below the center of the imaging screen, the horizontal direction is projected narrower than the actual one, and the vertical direction is projected narrower than the actual one. This is based on the perspective difference between the photographing means and the measurement object. If the cross-sectional area of the conveyed earth and sand is determined by the image processing means in such a state, the measurement error increases.

On the other hand, this type of measuring device is often used in a narrow place such as a tunnel construction site.
In addition, when used outdoors, it is often covered with a case to block sunlight, and in any case, the distance between the imaging means and the conveyed sediment, which is the object to be measured, should be sufficiently large. difficult.

Therefore, in this type of measuring apparatus, a wide-angle lens having a short focal length is employed as an imaging means. Such a wide-angle lens has a large distortion, and if such a distortion is not corrected, There is a problem that a measurement error becomes very large.

The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a method of measuring the amount of conveyed soil with a small measurement error.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for photographing a contour of conveyed earth and sand on a conveyor at a fixed position, and based on the photographed outline, the conveyed earth and sand every predetermined time. Is calculated by image processing, the obtained cross-sectional area is multiplied by the conveying speed of the conveyor, the conveyed soil amount is calculated every predetermined time, and the integrated value is calculated from the obtained conveyed soil amount. In the soil volume measurement method, before performing the actual measurement of the transported sediment, in advance, to produce a plurality of plane models having different contour shapes of known cross-sectional area, under the same conditions as the actual measurement, photograph each plane model, The calculated cross-sectional area of each plane model is obtained by image processing, a correction reference is created based on the calculated cross-sectional area and the known cross-sectional area, and when the conveyed soil is actually measured, the measurement is performed based on the correction reference. Corrected cross section It was so. According to the method for measuring the amount of transported soil configured in this manner, before actually measuring the transported soil, a plurality of plane models having different contour shapes of known cross-sectional areas are prepared in advance, and each plane model is manufactured under the same conditions as the actual measurement. The model is photographed, the calculated cross-sectional area of each plane model is obtained by image processing, and a correction standard is created based on the calculated cross-sectional area and the known cross-sectional area. The cross-sectional area actually measured is corrected based on this. When the plane model is photographed and the calculated cross-sectional area of each plane model is obtained by image processing, errors due to the perspective difference of the object to be measured and distortion errors of the lens system of the imaging unit are included. Is used to create a correction standard.
Perspective and lens system distortion errors are eliminated, and as a result accuracy can be greatly improved. The plane model can be set in four stages from a minimum value to a maximum value of the transported soil amount. When such a plane model is used, more effective correction can be performed in response to a change in the amount of soil transported.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 5 show an embodiment of the method for measuring the amount of soil transported according to the present invention.

In the measuring method shown in these figures, as shown in FIG.
A cover 12 is provided around the object, and the cover 12 covers the transported sediment A, which is an object to be measured. On the inner surface side of the cover 12, a lighting fixture 14 used for photographing the transported sediment A is provided. ing.

The conveyor 10 is provided with a belt 16 which is conveyed and moved in the direction of the arrow in FIG. 1 by a drive motor (not shown), and the conveyed sediment A is fed onto the belt 16 and conveyed. At this time, the transport speed V is constantly measured by, for example, the number of rotations of the driving motor of the belt 16.

The measuring device for measuring the soil volume X of the conveyed sediment A includes an imaging camera 20 for imaging the contour B of the conveyed sediment A conveyed on the conveyor 10 at a fixed position, and a control arithmetic unit 22.
And a display monitor 24.

The imaging camera 20 is composed of a digital camera having a predetermined number of pixels. The imaging camera 20 is located on the upper front side of the lighting fixture 14 with respect to the conveying direction of the conveyed earth and sand A, and has a belt at a predetermined inclination angle θ. 16 is to be photographed.

The control arithmetic unit 22 controls the on / off of the lighting equipment 14 when photographing the conveyed sediment A with the imaging camera 20, or controls the lighting fixture 14 every unit time based on the contour B imaged by the imaging camera 20. The image processing function for calculating the cross-sectional area s of the transported sediment A is also provided.

Further, the control arithmetic unit 22 includes the conveyor 10
Is multiplied by the cross-sectional area s to calculate a unit soil volume x per unit time, and sequentially integrate the unit soil volume x to obtain an integrated soil volume Xn, which is displayed. It also has a function of displaying on the monitor 24.

FIG. 2 shows the principle of measurement when the transported soil amount X is obtained from the contour B photographed by the imaging camera 20. When obtaining the transported soil amount X, it is necessary to obtain the cross-sectional area s from the outline B captured by the imaging camera 20.

In this case, first, as shown in FIG. 2 (A), the transported earth and sand A is not placed on the belt 16, but the empty state is photographed by the imaging camera 20, and the belt of the imaged screen is taken. Measurement window (2nd line)
(A shape corresponding to the maximum shape of the conveyed sediment A that can be placed on the belt 16) is set.

Next, as shown in FIG. 2 (B), the transported earth and sand A is placed on the belt 16, and the illumination equipment 14 irradiates the earth and sand A from above while the earth and sand A is being transported. Is formed, and this state is photographed by the imaging camera 20.

Then, the screen obtained by this photographing is binarized to obtain a contour B of the conveyed sediment A as shown in white in FIG. 2C, and the number of pixels in the contour B (The number of pixels).

When the number of pixels in the outline B is obtained, 1
By obtaining the real image area per pixel in advance, by multiplying them, the cross-sectional area s of the portion cut by the light cutting section can be obtained.

Although the basic principle of the above-described measuring method is not fundamentally different from the case of using a conventional measuring device,
The measurement method of this example has a remarkable difference in the points described below.

That is, in the case of the present embodiment, before the actual measurement of the conveyed sediment A, a plurality of plane models M1 to M4 having known sectional areas and different contour shapes are prepared in advance, and under the same conditions as the actual measurement, Each plane model M1 to M4 is photographed, and the calculated cross-sectional area sm1 for each plane model M1 to M4 is obtained by image processing.
To sm4, a correction standard is created based on the calculated cross-sectional areas sm1 to sm4 and the known cross-sectional areas s1 to s4. Is corrected.

FIG. 3 shows an example of the plane models M1 to M4 used in the measuring method of the present invention. In the four plane models M1 to M4 shown in the same figure, the hatched portions are painted black, and the black portions correspond to the placement shape of the conveyed sediment A on the belt 16, that is, the contour B. It is made to do.

The four plane models M1 to M4 correspond to the belt 1
6 is set so as to be located between the minimum value and the maximum value and between the minimum value and the maximum value with respect to the amount of the conveyed sediment A that can be placed on the plane model 6, the plane model M1 corresponds to the minimum value, It corresponds to the maximum value.

The length of the underline of the plane model M1 is 294.42.
9 mm is the width of the belt 16 actually used, and the inclination of the side surfaces of the plane models M <b> 2 to M <b> 4 corresponds to the side surface shape of the actually used belt 16 expanded in an inverted C shape.

The actual area of each of these plane models M1 to M4 is calculated in advance on the basis of the illustrated dimensions to obtain known sectional areas s1 to s4. The known cross-sectional areas s1 to s4 can be calculated by the
At 0, each of the plane models M1 to M4 can be obtained by directly photographing.

After the plane models M1 to M4 are manufactured, each of the plane models M1 to M4 is then manufactured under the same conditions as those of the actual measurement.
M4 is photographed, and each plane model M1 to M is processed by image processing.
The computational cross-sectional areas sm1 to sm4 for every four are obtained.

FIG. 4 shows an installation state of the imaging camera 20 when obtaining the calculation areas sm1 to sm4.
The installation state of the imaging camera 20 shown in FIG. 4 is in accordance with the actual measurement, the imaging camera 20 used for the actual measurement is used, and the imaging camera 20 is located at the center C0 of the plane models M1 to M4 to be photographed. And a vertical distance L2 (actual installation distance of 433 mm) so that the shooting angle θ (actual installation angle is 30 °) and a distance of L1 in the horizontal direction (actual installation distance 750 mm). ing.

Each of the plane models M1 to M4 is photographed by the imaging camera 20 under the conditions according to the actual measurement, and the number of pixels of each outline B of the obtained imaging screen is counted based on the above-described measurement principle. Then, each plane model M1
The calculation sectional areas sm1 to sm4 for each M4 are obtained.

Table 1 below shows the values of the calculated sectional areas sm1 to sm4 obtained in this manner. When the values of the calculated sectional areas sm1 to sm4 are obtained, a correction reference is created based on the calculated sectional areas sm1 to sm4 and the known sectional areas s1 to s4.

[0034]

[Table 1]

FIG. 5 shows a case where this correction reference is graphed. In the figure, the vertical direction is the magnitude of the area change rate, and the cross-sectional area change rate is the known cross-sectional area s1.
The size of the calculated cross-sectional areas sm1 to sm4 with respect to 〜s4 is expressed as a percentage.

The horizontal direction in FIG.
〜Sm4 values are shown. As can be seen from FIG. 5, as in the present invention, the transported sediment A is photographed from obliquely above by the imaging camera 20, and the obtained imaging screen is subjected to image processing to determine the cross-sectional area of the transported sediment A on the belt 16. It can be seen that the smaller the amount of the transported sediment A, the smaller the calculated cross-sectional area than the actual cross-sectional area.

When such a correction criterion is created, when the transported sediment A is actually measured, the cross-sectional area s actually measured based on the correction criterion is corrected. The correction criterion can be used as a calibration graph as shown in FIG. 5, or a correction table quantified in advance is created and stored in, for example, a memory of the control operation device 22. The calculation sectional areas sm1 to sm4 may be automatically corrected by a procedure incorporated in a program.

According to the above-described measuring method, a plurality of plane models M1 to M4 having different sectional shapes with known cross-sectional areas are prepared in advance before the actual measurement of the conveyed sediment A, and the same conditions as those of the actual measurement are obtained. Then, photograph each plane model M1 to M4,
The calculated cross-sectional areas sm1 to sm4 for each of the plane models M1 to M4 are obtained by image processing, and the calculated cross-sectional areas sm1 to sm4 are calculated.
Based on the known cross-sectional areas s1 to s4, a correction criterion is created, and when the transported sediment A is actually measured, the actually measured cross-sectional area s is corrected based on the correction criterion.

Here, when the plane models M1 to M4 are photographed and the calculated cross-sectional areas sm1 to sm4 for each of the plane models M1 to M4 are obtained by image processing, the perspective difference of the object to be measured, ie, the conveyed soil A Error due to the
And the calculated cross-sectional area sm1
Since the correction criterion is created based on sm4, as a result, the perspective difference and the lens system distortion error are excluded from the corrected measurement of the transported soil amount, and the measurement accuracy can be greatly improved.

In this embodiment, the plane model M
Since 1 to M4 are set in four steps from the minimum value to the maximum value of the transported soil amount, more effective correction can be performed according to the change in the transported soil amount.

In the above embodiment, the case where four types of plane models M1 to M4 are used has been described as an example. However, the present invention is not limited to this, and even if a larger number of plane models are used. Good.

[0042]

As described in detail above, according to the method for measuring the amount of conveyed soil according to the present invention, high-precision measurement can be performed by eliminating distance and lens errors during imaging.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a measuring state of a method for measuring the amount of conveyed soil according to the present invention.

FIG. 2 is an explanatory view of the principle of the cross-section calculation in the measurement method of FIG. 1;

FIG. 3 is a front view showing an example of a plane model used for the measurement method shown in FIG.

FIG. 4 is an explanatory diagram of an imaging method of the plane model shown in FIG. 3;

FIG. 5 is an explanatory diagram of a correction graph used in the method for measuring the amount of conveyed soil according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Conveyor 12 Cover 14 Lighting equipment 16 Belt 18 Control arithmetic unit 20 Imaging camera 22 Display monitor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Watanabe 2-15-2 Konan, Minato-ku, Tokyo Obayashi Corporation Headquarters (72) Inventor Yoshio Sakai 958-28, Ariyasu, Aria, Shonai-cho, Kaho-gun, Fukuoka Inside the Kobukuro Works (72) Inventor Masayuki Kusano 958, Ariyasu, Oaza, Shonai-cho, Kaho-gun, Fukuoka Prefecture F-term (reference) 2D054 DA02 DA31 2F030 CC20 CE04 2F065 AA52 AA59 BB05 CC00 FF04 JJ03 JJ08 JJ26 JJ26 MM03 QQ04 QQ32 RR05 UU05 5L096 BA18 CA04 DA01 FA06 FA59 FA67 GA28

Claims (2)

[Claims] An image of a contour of conveyed soil on a conveyor is taken at a fixed position, and a cross-sectional area of the conveyed sand at predetermined time intervals is calculated by image processing based on the photographed outline, and the obtained cross-sectional area is obtained. Multiplying the conveyor speed of the conveyor, to calculate the amount of soil transported for each predetermined time, in the method of measuring the amount of soil transported to obtain the integrated value from the amount of transported soil obtained, before the actual measurement of the transported soil In advance, a plurality of plane models having known cross-sectional areas having different contour shapes are prepared, each plane model is photographed under the same conditions as the actual measurement, and the calculated cross-sectional area of each plane model is obtained by the image processing. Based on the cross-sectional area and the known cross-sectional area, a correction standard is created, and when the conveyed soil is actually measured, the cross-sectional area measured based on the correction standard is corrected. Measuring method. 2. The method for measuring the amount of soil carried, wherein the plane model is set in four stages from a minimum value to a maximum value of the amount of soil carried.