JP2000304511A - Soil volume measuring method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly and accurately measure the volume of soil. SOLUTION: Soil 1 is loaded onto an upper-end-opened carrying vessel 2 whose three-dimensional shape is known, and the three-dimensional coordinates of an upper end edge 3a of the carrying vessel 2 and the surface of the load earth 1 are measured by a downward three-dimensional image measuring apparatus 5. The three-dimensional coordinates of a shape of the carrying vessel 2 is determined from the three-dimensional coordinates of the upper end edge 3a of the carrying vessel 2, and the volume of the soil 1 is calculated from the three-dimensional coordinates of the surface of the loaded soil 1 and the three-dimensional coordinates of the shape of the carrying vessel 2. It is preferable that a light projector 10 projecting a group of slit lights combined in a lattice type and a stereo type image sensing devices 12R, 12L measuring three- dimensional coordinates of each cross point of a lattice pattern formed by the projection of the group of the slit lights are contained in the measuring apparatus 5, and the three-dimensional coordinates are measured by a stereo image sensing method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring soil volume, and more particularly to a method and an apparatus for accurately measuring the volume of excavated soil or unloaded soil (hereinafter referred to as soil volume) at an earthworks site.

[0002]

2. Description of the Related Art For example, soil (including soil and sand; the same applies hereinafter) generated by excavation of ground in earthworks is carried out from a construction site by loading it on a dump truck or the like and reclaimed at another construction site. To be served. Conventionally, when measuring the amount of excavated soil or the amount of unloaded soil from the viewpoint of construction management, the following method is often used.

(1) The shape of the ground before and after excavation is measured, and the amount of excavated soil is determined from the difference between the ground shapes before and after excavation. (2) When the excavated soil is carried out by a truck or the like, the weight of the truck before and after loading the soil is measured by a measuring device such as a truck scale using a load cell, and the difference in weight before and after the loading is measured in the soil at the ground. By indirectly dividing by the unit volume weight of, the amount of excavated soil is obtained indirectly.

[0004]

However, the conventional method of (1) determining the soil volume from the difference in ground shape before and after excavation is that the volume of the soil loosened from the ground condition changes according to the soil volume change rate. and from the fact that also soil the amount of the rate of change itself differs depending on the nature of the soil, "carry-out and transport the soil amount or What is the m ^3"
There is a problem that accurate soil volume cannot be obtained when managing soil volume based on the standard.

The conventional method of (2) indirectly calculating the soil volume from the weight difference before and after loading is also a method in which the unit volume weight of the soil in the ground is not uniform and the volume is indirectly calculated by division. For this reason, there is a problem that an error is accumulated and an accurate soil volume cannot always be obtained.

On the other hand, with the progress of computerization of construction management, high-quality construction management by accurate soil volume management is required.

It is an object of the present invention to provide a soil volume measuring method and apparatus for directly and accurately measuring the volume of soil.

[0008]

Referring to the embodiments of FIGS. 1 and 2, a method for measuring the volume of soil according to the present invention is a method for measuring the volume of soil. The soil 1 is loaded in the container 2, the three-dimensional coordinates of the upper edge 3 a of the transporter 2 and the surface of the loaded soil 1 are measured by the downward three-dimensional image measurement device 5, and the three-dimensional coordinates of the upper edge 3 a of the transporter 2 are measured. The three-dimensional coordinates of the shape are determined, and the volume of the soil 1 is calculated from the three-dimensional coordinates of the surface of the loading soil 1 and the three-dimensional coordinates of the shape of the carrier 2.

Referring to FIGS. 1 and 2, a soil volume measuring device according to the present invention is a device for measuring the volume of soil, which is a storage means for storing a three-dimensional shape of an upper end open conveyor 2 for loading soil. 6. The measuring chamber 17 into which the transporter 2 after soil loading can enter, and the upper edge 3a of the transporter 2 which is mounted downward on the upper part of the measuring chamber 17
And a three-dimensional image measuring device 5 for measuring the three-dimensional coordinates of the surface of the loading soil 1, coordinate assigning means 7 for determining three-dimensional coordinates of the shape of the transporter 2 from the three-dimensional coordinates of the upper edge 3a, and the surface of the loading soil 1. And a volume calculating means 8 for calculating the volume of the soil 1 from the three-dimensional coordinates of the carrier 2 and the three-dimensional coordinates of the shape of the carrier 2.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a system block diagram of a soil volume measuring device of the present invention, and FIG. An example in which the amount of soil loaded on the vessel is measured by the apparatus shown in FIG. The three-dimensional image measurement device 5 in FIG. 1 projects a group of visible slit light (hereinafter, referred to as mesh light) combined with a pair of stereo image pickup devices 12R and 12L, for example, a CCD camera device, in a grid pattern. The projector 10 has coordinate calculation means 15 for calculating three-dimensional coordinates from a pair of two-dimensional images by the imaging devices 12R and 12L, and three-dimensional coordinates of a measurement target based on a stereo image method which is an example of a three-dimensional image measurement method. Is to measure. Coordinate calculation means 15
One example is a program built in the computer 16, and reference numeral 14 in the figure denotes an image input board connected to the computer 16.

The stereo image method is, as shown in FIG.
A pair of imaging devices 12R provided at different positions, 12L by photographing the measurement target 19 from different directions, the imaging devices 12R, the two-dimensional image Iw _R of 12L, the two-dimensional coordinates (the images of the object 19 in Iw _L This is an image measurement method for obtaining the three-dimensional coordinates of the object 19 from the position coordinates of the corresponding horizontal and vertical pixels on the image. Briefly explaining the principle of the stereo image method with reference to the figure, the three-dimensional coordinates of the point P on the measurement object 19 (X, Y, Z) , a point in the coordinate system of the image Iw _R of the imaging device 12R P The two-dimensional coordinates of the image Pa of (Xa, Ya), the imaging device 12
The two-dimensional coordinates of the image Pb of the point P in the coordinate system of the image Iw _L of _L
When (Xb, Yb) is used, the conversion formula from the point P to the image Pa and the image Pb can be expressed as the following formulas (1) and (2) using the homogeneous coordinate system expression of each coordinate. Where (X, Y, Z, 1) ^T , (Xa,
Ya, 1) ^T , (Xb, Yb, 1) ^T are points P in homogeneous coordinate system representation,
The coordinates of the image Pa and the image Pb are shown, and the title T indicates a transposed matrix.

The coordinates (Xa, Ya) and (Xb, Yb) are obtained from the images Iw _R and Iw _L of the image pickup devices 12R and 12L, and are substituted into equations (1) and (2).
By expanding and rearranging equations (1) and (2) using Ha and Hb expressed by (3) and (4), equations (5) to (8) are obtained. Matrix defined by equation (9)
Formulas (5) to (8) are summarized using F, Q, and V, and F = QV (Formula (10))
Therefore, the three-dimensional coordinates (X, Y, Z) can be calculated from Expression (11) on condition that the inverse matrix Q ⁻¹ exists. That is, in the stereo image method, if the conversion parameters such as the matrices A and B in the equations (1) and (2) are determined, it is possible to simultaneously obtain the three-dimensional coordinates of a plurality of images from the pair of two-dimensional images Iw _R and Iw _L. It is possible. Note that stereo image measurement by three or more imaging devices 12 is also possible, and the number of rows of the matrices F and Q increases according to the number of imaging devices 12.

[0013]

(Equation 1)

However, in the stereo image method, it may be difficult to detect the corresponding points Pa and Pb on the pair of two-dimensional images Iw _R and Iw _L (hereinafter, referred to as matching). In FIGS. 1 and 2, a mesh light is projected onto a measurement target, and a lattice pattern (hereinafter, referred to as a mesh) formed on the measurement target by projecting the mesh light is photographed by a pair of imaging devices 12R and 12L. Dimensional image
Detecting intersections of mesh images on Iw _R and Iw _L (hereinafter referred to as mesh intersections) facilitates matching and increases accuracy. The mesh light can be a combination of slit laser light to prevent light scattering. Reference numeral 13 in FIG. 1 indicates a mesh light control circuit connected to the computer 16, and the interval between mesh lights is set to the computer 16.
And adjustment by the control circuit 13. However, the corresponding points for matching are not limited to the projection of the mesh light, but may be formed by other methods such as projection of a large number of spot lights.

Referring now to FIG. 2, a description will be given of a case where the volume of soil loaded on the truck / vessel is measured by the three-dimensional image measuring device 5 of FIG. However, the transporter 2 used in the present invention is not limited to a track vessel. The three-dimensional image measuring device 5 used in the present invention is not limited to the one based on the stereo image method, but may be based on a spot light projection method, a slit light projection method, a pattern light projection method, a moire topography, or the like. it can.

In FIG. 2, a support frame 4 that defines a measurement room 17 into which the transporter 2 can enter is installed at an arbitrary place on the earth work site,
The three-dimensional image measurement device 5 is attached to the support frame 4 above the measurement room 17 downward. The illustrated support frame 4 includes a pair of portal members 4a and 4b that straddle the transporter 2 at predetermined intervals,
a and a beam member 4c connecting between the tops of 4b. The truck enters the measuring room defined by the pair of portal members 4a, 4b, and the downward measuring device 5 measures the volume of the vessel loaded on the vessel.

Although the illustrated example shows the measuring device 5 having two image pickup devices 12R and 12L, three or more image pickup devices 12 may be used to improve measurement accuracy. The mounting position of the measuring device 5 on the support frame 4 should be determined after examination so that the entire track vessel and the mesh light can be uniformly projected on the entire vessel in the imaging range of each of the imaging devices 12R and 12L. Is not limited to the illustrated example.

FIG. 5 shows an example of a flow chart of the soil volume measurement in FIG. First, in step 501, the three-dimensional shape of the transporter 2 is measured and stored in the storage means 6 (FIG. 1). When the transporter 2 is a truck vessel, the three-dimensional shape of the loading surface 3b and the upper edge 3a of the vessel 2 shown in FIG. 3B is measured, and for example, a three-dimensional graphic as shown in FIG. Images Ig _3b and Ig _3a are stored in the storage means 6. The three-dimensional shape of the loading surface 3b and the upper end edge 3a of the transporter 2 may be obtained by, for example, the three-dimensional image measuring device 5 before loading the soil.
A three-dimensional design shape of the transporter 2 created by AD or the like may be used. Once the three-dimensional coordinates of the transporter 2 are measured and stored,
Since it is sufficient to read the stored data from the next soil volume measurement, step 501 can be omitted.

At step 502, the transporter 2 after loading the soil is moved into the measurement room and stopped, and at step 503, the conversion parameters of the stereo image method are calibrated. The conversion parameters include the matrices A and B in the above equations (1) and (2). For calibration of the conversion parameter (hereinafter, sometimes referred to as calibration), for example, three-dimensional coordinates ((X, Y, Z) of the equations (1) and (2)) are known in advance in the imaging range of the imaging devices 12R and 12L. 6 or more reference points (not shown) are set, and an imaging device is provided for each of the reference points.
Two-dimensional coordinates on each image of 12R and 12L ((Xa, Y in equations (1) and (2)
a), (Xb, Yb)). For calibration of the stereo image method,
The present inventor has disclosed in detail Japanese Patent Application Laid-Open No. Hei 8-219783, which disclosed a displacement measurement management system for excavation ground and the like.

Once the conversion parameters of the stereo image method are calibrated, the same conversion parameters can be used in the subsequent soil volume measurement as long as the positions, postures, lens focal lengths, etc. of the imaging devices 12R and 12L are constant. So step 50
3 can be omitted.

In steps 504 and 505, the mesh light is projected from the light projector 10 onto the carrier 2, and the image pickup devices 12R and 12L
Photograph the upper edge 3a of the transporter and the surface of the loading soil 1. FIG. 3A shows the mesh intersection 18 on the surface of the loaded soil viewed from the back of the truck, and FIG. 4 shows two-dimensional images Iw _R and Iw _L taken by the imaging devices 12R and 12L. As shown in the drawing, the mesh intersection 18 in a two-dimensional image Iw _R, Iw _L so can be observed as an image 18R, 18L, can corresponding points easily detected in the two-dimensional image Iw _R, Iw _L. The images Iw _R and Iw _L can be displayed on a display device (not shown) of the computer 16 and can be confirmed. 3 and 4, the support frame 4 is omitted.

[0022] At step 506, the two-dimensional image Iw _R by the coordinate calculation unit 15, each mesh intersection image 18R of Iw _L, 18L of the two-dimensional coordinates (Equation (1) (2) (Xa, Ya), (Xb, Yb)), and using the conversion parameters A and B calibrated in step 503, the three-dimensional coordinates (Eq. (1)) of each mesh intersection 18 based on Eq.
(2) (X, Y, Z)) is calculated. If the mesh light interval is made sufficiently small, a set of the three-dimensional coordinates of the mesh intersection 18 can be regarded as the three-dimensional coordinates of the upper edge 3a of the transporter and the surface of the loading soil 1 substantially. FIG. 3 shows an example of three-dimensional graphic images Ig _3a and Ig ₁ of the upper edge 3a of the vessel 2 and the surface of the loading soil 1 created by a set of three-dimensional coordinates of the mesh intersection 18.
It is shown in (C).

For example, as shown in FIG. 3A, when the upper edge 3a of the transporter 2 is present on the peripheral edge of the surface of the loading soil 1, in the set of three-dimensional coordinates of the mesh intersection 18 obtained in step 506, The three-dimensional coordinates of the mesh intersection 18 in the peripheral portion can be considered as the three-dimensional coordinates of the upper edge 3a of the transporter. In order to more easily and reliably determine the three-dimensional coordinates of the upper edge 3a of the transporter, optotypes 20a to 20d that can be distinguished from the mesh intersection 18 may be attached to the upper edge 3a of the transporter as shown in FIGS. . In this case, in step 506, the two-dimensional coordinates of the optotype images 20R and 20L together with the mesh intersection images 18R and 18L are obtained from the two-dimensional images Iw _R and Iw _L, and the three-dimensional coordinates of the index 20 are calculated together with the mesh intersection 18. For example, when the upper edge 3a of the vessel 2 is on the same plane, the three-dimensional coordinates of the upper edge 3a can be obtained from the three-dimensional coordinates of three or more indices 20 attached to the upper edge 3a.

In step 507, the three-dimensional coordinates of the shape of the transporter 2 are determined from the three-dimensional coordinates of the upper edge 3a of the transporter obtained in step 506 by the coordinate allocating means 7 in FIG. For example, the three-dimensional coordinates of the mounting surface 3b of the transporter 2 can be determined from the three-dimensional coordinates of the upper edge 3a of the transporter and the design dimensions of the transporter 2. The three-dimensional coordinates of the loading surface 3b of the transporter 2 determined in this step are the three-dimensional coordinates of the bottom surface of the loading soil 1 in contact with the vessel 2. That is, as shown in FIG.
In steps 506 and 507, the three-dimensional coordinates of the entire surface of the loading soil 1 are determined from the three-dimensional coordinates of the surface of the loading soil and the three-dimensional coordinates of the shape of the transporter 2. One example of the coordinate allocating means 7 is an image processing program built in the computer 16.

FIG. 3C shows a case where the loading soil surface is above the upper edge 3a of the transporter 2, but the loading soil surface is below the upper edge 3a of the transporter 2 as shown in FIG. Also,
The three-dimensional coordinates of the entire surface of the loading soil 1 can be determined from the three-dimensional coordinates of the surface of the loading soil and the three-dimensional coordinates of the shape of the transporter 2.

When the three-dimensional coordinates of the entire surface of the loading soil 1 are determined, in step 508, the volume of the loading soil 1 can be calculated by the volume calculating means 8 in FIG. An example of the volume calculation method is to calculate the volume of the loading soil 1 from the three-dimensional coordinates of the entire surface of the loading soil 1 using, for example, an average cross-section calculation method for each of the vertical and horizontal cross sections of the mesh. One example of the volume calculating means 8 is a program built in the computer 16 for calculating the volume from the three-dimensional coordinates of the three-dimensional surface by the average sectional calculation method. However, the volume calculation method is not limited to the average cross-section calculation method, and other conventional techniques for obtaining the volume from the three-dimensional coordinates of the three-dimensional surface can be used.

After accumulating the volume of the loaded soil 1 in step 509, it is determined in step 510 that the soil volume measurement has been completed.
Return to step 502 to continue soil volume measurement or end the measurement. At the earth work site, the amount of unloaded soil can be managed by accumulating the volume of soil loaded on the vessel of the unloading truck. The accumulated soil volume can be output to a display device or a printing device of the computer 16 at any time and used for construction management.

According to the present invention, the amount of excavated soil and the amount of unloaded soil can be directly and accurately measured irrespective of the rate of change in soil volume and the unit weight of soil, thereby improving the level of soil volume management. be able to. In addition, automatic measurement of soil volume is possible by combination with a carrier identification system, etc., which can contribute to simplification of construction management and cost reduction.

Thus, the object of the present invention, that is, the "method and apparatus for measuring soil volume directly and accurately measuring the volume of soil" can be achieved.

In the flowchart of FIG. 5, the soil amount is measured after stopping the transporter 2 (step 502). However, the soil volume measurement of the present invention is performed if the three-dimensional coordinates of the upper edge 3a of the transporter and the surface of the loaded soil can be measured. Stopping the transporter 2 is not essential because it is sufficient.

[0031]

When the support frame 4 shown in FIG. 2 is installed on an earthwork site, the brightness of the mesh light projected from the projector 10 of the three-dimensional image measuring device 5 is weakened by sunlight, and the two-dimensional image Iw _R , I
w It may be difficult to detect the corresponding point in _L. In the embodiment shown in FIG. 2, a dark curtain that covers the measurement room as necessary so that undesired light enters the measurement room 17 from the outside and the mesh image projected on the carrier 10 is not erased. Can be attached to the support frame 4.

The case where the carrier 2 is not deformed by the loading of the soil 1 has been described above. For example, even when the carrier 2 can be deformed by the loading of the soil 1, the deformation amount of the three-dimensional shape of the If foreseeable, the present invention can be applied. For example, when the deformation amount of the three-dimensional shape of the transporter 2 depends only on the load weight, the deformation amount of the transporter 2 according to the load weight is measured in advance and stored in the storage unit 6 of FIG. A weight measuring device 9 for measuring the weight of the loaded soil is provided, and the coordinate allocating means 7 determines the shape of the transporter 2 based on the three-dimensional coordinates of the upper edge 3a of the transporter 2 and the deformation amount of the transporter 2 according to the loaded weight. It is also possible to determine the three-dimensional coordinates of Further, by taking into account the amount of deformation of the transporter 2 according to the soil loading position, the present invention can be expected to be applied to, for example, measurement of the amount of soil loaded on a belt conveyor.

[0033]

As described above, the method and apparatus for measuring soil volume according to the present invention load soil in a top-open carrier having a known three-dimensional shape and use a downward three-dimensional image measuring device to measure the top edge of the carrier. And measuring the three-dimensional coordinates of the loading soil surface and determining the three-dimensional coordinates of the transporter shape from the three-dimensional coordinates of the upper edge of the transporter, and determining the soil from the three-dimensional coordinates of the loading soil surface and the three-dimensional coordinates of the transporter shape. Since the volume is calculated, the following remarkable effects are obtained.

(A) Excavated soil volume and unloaded soil volume can be measured directly and accurately regardless of the soil volume change rate and the unit volume of soil. (B) Improvement of the quality and level of construction management can be expected by accurate soil volume measurement. (C) Compared to the conventional measurement method using surveying or the like, simple and quick soil volume measurement can be performed, so that soil volume management costs can be reduced. (D) Mesh light projectors and stereo imaging devices can be used, and measurement accuracy can be improved by adjusting mesh light intervals. (E) Contribution to automation of soil volume measurement can be expected by combination with a carrier identification system and the like. (F) The construction of an automatic soil volume measurement system can be expected to simplify construction management and reduce management costs.

[Brief description of the drawings]

FIG. 1 is a system block diagram of the present invention.

FIG. 2 is an explanatory diagram of one embodiment of the present invention.

FIG. 3 is an explanatory diagram of soil volume measurement according to the present invention.

FIG. 4 is an explanatory diagram of a pair of stereo images.

FIG. 5 is an example of a flowchart of soil volume measurement according to the present invention.

FIG. 6 is another explanatory diagram of soil volume measurement according to the present invention.

FIG. 7 is an explanatory diagram of a three-dimensional image measurement method using a stereo image method.

[Description of Signs] 1 soil 2 transporter 3a transporter upper edge 3b transporter loading surface 4 support frame 4a, 4b portal member 4c beam member 5 three-dimensional image measuring device 6 storage means 7 Coordinate allocating means 8 Volume calculating means 9 Weight measuring device 10 Projector 11 Mesh light 12R, 12L Imaging device 13 Mesh light control circuit 14 Image input board 15 Coordinate calculating means 16 Computer 17 Measurement Room 18… Mesh intersection 19… Measurement target 20… Target Iw… 2D image Ig… 3D graphic image

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoru Miura 2-191-1, Tobita-Ki, Chofu-shi, Tokyo Kashima Construction Co., Ltd. (72) Inventor Izumi Kuronuma 2-9-1-1, Tobita-Kibito, Chofu-shi, Tokyo Kashima Construction Co., Ltd.Technical Research Institute (72) Inventor Shozo Aoki 1-2-7 Moto Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Yuji Ota 1-2-Chome Moto-Akasaka, Minato-ku, Tokyo No. 7 Kashima Construction Co., Ltd. F term (reference) 2F014 FA04 2F065 AA04 AA53 AA59 CC00 DD12 DD15 FF01 FF04 FF05 HH06 HH13 JJ03 JJ05 JJ08 JJ26 PP01 QQ23 QQ31 SS06 SS11

Claims (7)

[Claims] 1. A method for measuring the volume of soil, comprising loading soil in an upper-end open carrier having a known three-dimensional shape, and using a downward three-dimensional image measuring device to measure a third order of the upper edge of the transporter and the surface of the loaded soil. The original coordinates are measured, the three-dimensional coordinates of the shape of the transporter are determined from the three-dimensional coordinates of the upper edge, and the volume of soil is calculated from the three-dimensional coordinates of the loading soil surface and the three-dimensional coordinates of the transporter shape. Soil volume measurement method. 2. The measuring method according to claim 1, wherein the three-dimensional shape of the transporter is obtained by measuring the shape of the upper edge and the loading surface of the transporter with the measuring device before loading the soil. Quantity measurement method. 3. The measuring method according to claim 1, wherein the three-dimensional image measuring device projects a group of slit lights combined in a grid pattern and a grid formed by projecting the group of slit lights. A soil volume measuring method including a stereo-type imaging device for measuring three-dimensional coordinates of each intersection of a pattern. 4. A soil volume measuring method according to claim 1, wherein said carrier is used as a carrier of a dump truck. 5. An apparatus for measuring the volume of soil, comprising: storage means for storing a three-dimensional shape of an upper end open transporter for loading soil;
A measuring chamber into which the transporter after soil loading can enter, a three-dimensional image measuring device attached downward to the upper part of the measuring chamber and measuring three-dimensional coordinates of the upper edge of the transporter and the surface of the loaded soil, three-dimensional of the upper edge It is provided with coordinate allocating means for determining three-dimensional coordinates of the shape of the transporter from coordinates, and volume calculating means for calculating the volume of soil from the three-dimensional coordinates of the surface of the loading soil and the three-dimensional coordinates of the shape of the transporter. Soil volume measurement device. 6. A measuring device according to claim 5, wherein the three-dimensional image measuring device has a light projector for projecting a group of slit lights combined in a grid and a lattice pattern formed by projecting the group of slit lights. A soil volume measuring device including a stereo-type imaging device that measures three-dimensional coordinates of each intersection. 7. The soil volume measuring device according to claim 5, wherein a dark curtain for preventing light from entering from outside is provided in the measuring room.