KR101004021B1 - Weighing method using distance measuring unit - Google Patents

Abstract

The present invention comprises the steps of: dividing a load into an arbitrary block using point distance measuring means; Obtaining a volume of each divided block; Adding the volumes of all blocks to obtain the total volume of the load; The total volume is multiplied by the average density of the load to obtain a weight; relates to a method for measuring the weight of the load in the storage, including, there is no error due to disturbances can be measured more accurately, as well as the volume, height of the load Various types of information such as surface shape can be obtained for more efficient inventory management.

Description

Weighing method using the point measuring device {Weighing method using distance measuring unit}

The present invention relates to a measuring method for determining the volume and ultimately the weight of a particulate load in which the surface of the stock has an irregular shape, for example, in a large hopper type reservoir, in particular the load in the reservoir has an irregular shape. Scan the surface using a point distance measuring means such as a laser distance sensor (which means setting multiple points and measuring the distance to these points) to approximately extract the irregular shape, and then The present invention relates to a method for measuring the weight of a load in a store using a point distance measuring means, which finds the total volume of and multiplies the average density of the load and converts it to weight.

At this time, the method of scanning the surface, by dividing the surface of the load into an arbitrary block to directly obtain the volume of each divided block, thereby calculating the volume of each block and adding the volume of all blocks to determine the total volume of the load After obtaining, the weight is obtained by multiplying the average density as described above.

In general, the weight of the load in a large reservoir is to install a pressure sensor at regular intervals on the wall of the reservoir, to find the position of the sensor under pressure, and to calculate the weight by roughly calculating the volume of the load. For example, there is a method of measuring the weight of the entire storage by measuring the weight of the entire storage using a weighing sensor such as a load cell or a microcell, and then subtracting the storage itself.

The pressure sensor or the weighing sensor is a kind of strain gauge, which is deformed when a tensile force or a compressive force is received. The pressure sensor or the weighing sensor detects the deformation caused by the pressure or the weight in the reservoir and measures the weight of the load in the reservoir.

These conventional weighing methods are affected by temperature and strong winds due to daily crossover and seasonal changes, and there are too many external factors that affect the measurement, such as errors due to connection with structures supporting the storage, and periodically zero and span. Although there is no proper standard weight and equipment, it is difficult to prove the reliability of the calibration. In addition, if the structure is changed, the zero point should be corrected, but if the structure is connected to another structure, the zero point correction is also impossible.

Therefore, the present invention was devised to solve the above problems, even if the surface of the load having an irregular shape by using a point distance measuring means to accurately calculate the volume after multiplying the density by multiplying the weight of the load, error Point distance measurement, which can minimize the disturbance caused by temperature, wind, structure, etc., make it easy to calibrate, and shape the surface of the load three-dimensionally using the data obtained. The purpose is to provide a means of weighing loads in a reservoir by means.

The present invention for achieving the above object comprises the steps of: dividing the load into an arbitrary block using point distance measuring means; Obtaining a volume of each divided block; Adding the volumes of all blocks to obtain the total volume of the load; And multiplying the total volume by the average density of the load to obtain a weight.

Hereinafter, a method for measuring the weight of a load in a storage room according to the present invention will be described in more detail with reference to the accompanying drawings.

Figure 1 is a perspective view of the reservoir, Figure 2 is a view for explaining a method for partitioning the upper surface of the load into a triangular region and a half-moon-shaped region, Figure 3 is further divided when the larger than the reference area of the triangular region It is a figure for demonstrating a method.

1 to 3 schematically show a reservoir and a granular load loaded therein, the reservoir being shown as a large hopper reservoir, but not limited thereto, having a polygonal cross section as well as a cylindrical reservoir. The method for measuring the weight of the load in the reservoir according to the present invention may also be applied to the reservoir. In addition, the load may be made of a particulate solid material, it may also be made of a liquid material, if the load is a liquid because the upper surface of the load forms a horizontal plane, it is easier to weigh the load in the reservoir according to the present invention. It can be implemented simply. In the present specification, the present invention will be described on the assumption that when the weight is difficult to measure in the conventional or conventional art, the reservoir is a hopper-type reservoir and the load is a granular load.

First, the point distance measuring means is installed at any position of the lid of the reservoir or the bottom of the beam horizontally across the upper surface of the reservoir. Here, since the apparatus for placing a load in the storage is mostly located in the center of the upper surface of the storage, it is difficult to install the point distance measuring means at the center of the upper surface of the storage. Therefore, the point distance measuring means is installed at a position separated by a predetermined distance s from the center point of the upper surface of the reservoir.

The point distance measuring means is composed of a device such as a laser distance sensor, an ultrasonic distance sensor, an electromagnetic distance measuring device, etc., and is determined between a vertical direction and a horizontal direction, that is, within a range of 180 degrees on the axis of the point distance measuring means installed in the beam of the storage. The inclination can be changed uniformly to the first angle of the following (hereinafter referred to as the inclination angle α), and a predetermined second angle (hereinafter referred to as the turning angle β) by mounting a step motor on the shaft. I can turn 360 degrees uniformly every time.

Accordingly, the point distance measuring means scans the surface of the load while the distance measuring direction is changed in the virtual vertical plane and the virtual horizontal plane at an angle uniformly divided by the inclination angle α and an angle uniformly divided by the turning angle β. Thus, it is possible to calculate what shape the load is and how high it is.

Of course, it is preferable to have a separate control device, which controls the driving of the point distance measuring means, receives data from the point distance measuring means, stores and calculates, and outputs various data.

Next, the point distance measuring means is turned horizontally to measure the distance to the wall surface of the reservoir while turning at a constant speed. Here, the position of the point distance measuring means is set to the origin 10, and the line connecting the origin 10 and the measured longest distance point is set to the Y axis while being perpendicular to the Y axis horizontally. After setting the line to the X axis, a virtual circle having a radius of the maximum distance on the Y axis about the origin 10 is set.

Then, the point distance measuring means is changed downward so as to be perpendicular to the Y axis to measure the distance to the load to measure the height of the load meeting the Z axis. That is, referring to FIG. 1, since the height H of the storehouse, that is, the height of the point distance measuring means is known, the distance from the origin 10 to the point 100 is measured, and the height H of the storehouse is measured. By subtracting the measured distance, it is possible to obtain the height of the load located at the point 100, that is, the Z value of the point 100.

Also, as will be described later, for the purpose of distance measurement, point position change, division into blocks, and the like, the point distance measuring means is to be rotated in the virtual horizontal plane and the angle of inclination α when the tilt is changed from the virtual vertical plane. Preset the angle of rotation (β) and the reference area of the triangle.

One of the main features of the method for measuring the weight of a load in a reservoir according to the present invention is that the upper surface of the load has an irregular shape, and the surface is rotated at the same angle (swivel angle) about the Z axis passing through the origin 10. In addition to setting a radial extension line by dividing, the extension line is divided again from the Z axis to the wall surface of the reservoir at a predetermined interval (by inclination angle), and a connecting line is connected to any point in the adjacent extension line. Partitions triangular and semi-moon-shaped areas with a size less than the reference area, extending each area divided by these lines vertically down to the bottom of the reservoir, and dividing the entire load into a number of blocks. Three-dimensional coordinates of the positions of the vertices on the top face of the block are used to find the volume of each block using the coordinate values of these points. The total weight of these blocks is multiplied by the average density of the load to calculate the weight.

As described above, in order to obtain the volume of the load, in particular, each block, three-dimensional coordinate values of the vertices on the upper surface of the block must be obtained. In order to know them, a trigonometric function must be calculated.

First, the point 100 can obtain the Z value, the X value (0) and the Y value (0) obtained from the height of the load measured as described above. This coordinate value is input to the controller.

Next, the distance d _101a from the origin 10 to the point 101a is measured through the point distance measuring means. If the extension line L101 is on an imaginary vertical plane that is the same as the Y axis, an X value (0) can be obtained, and the distance from the Z axis to the point 101a is d _101a × sinα, so this value can be set to Y value. Since the distance from the Y-axis to the point 101a is d _101a × cosα, the measured distance is subtracted from the height of the reservoir to obtain the height of the load located at the point 101a, that is, the Z value of the point 101a.

By applying this, it is possible to obtain a three-dimensional coordinate value of the other points 101b, 101c, ... on the extension line L101 while inputting the increased inclination angle each time the inclination angle increases in multiples. On the other hand, the end point of the extension line (L101) is a point that meets the wall surface of the store, and if the point that the X value and the Y value are recognized in spite of the inclination angle is increased, the end point is the point having the first X value and Y value Set to.

Similarly, the three-dimensional coordinate values of the points 102a, 102b, ... in the extension line L102 can be obtained. Since the extension line L102 is rotated by the turning angle β with respect to the extension line L101, If the distance from the home position 10 as measured by that distance measuring means to a point (102a) d _102a la, X value d _102a × sinα × sinβ and, Y values d _102a × sinα × cosβ and, Z value Is H-d _102a × cosα.

By applying this, it is possible to obtain three-dimensional coordinate values of all points in each extension line while inputting the increased inclination angle and the turning angle as the inclination angle and the turning angle increase in multiples.

In addition, the upper surface of the load should be partitioned into predetermined areas, and as described above, the point distance measuring means is changed to an arbitrary inclination angle α around the origin 10 and is on the same virtual vertical plane as the Y axis. After dividing and setting the points 101a, 101b, ... on the extension line L101 at, the distance measuring direction is changed by an arbitrary turning angle β about the Z axis, and then again the inclination angle α The points 102a, 102b, ... are dividedly set on the extension line L102 while being changed to. At this time, the end points where the extension lines (L101, L102) and the wall of the reservoir meet are also set as one point of the extension line. Next, the connecting line is connected to the shortest distance from each of the divided points 102a, 102b, ... on the extension line L102 to the divided points 101a, 101b, ... on the adjacent extension line L101, respectively. To partition the regions.

More specifically, as shown in FIG. 2, the connection line connecting the points 102a on the extension line L102 to all the points 101a, 101b, 101c ... on the extension line L101 is set and the length of each connection line is shown. Calculate At the same time, triangles DELTA 100, 101a, and 102a and triangles DELTA 101a, 102a and 101b are defined.

Subsequently, a connection line connecting the next point 102b on the extension line L102 to the points 101b, 101c ... on the extension line L101 is set and the length of each connection line is calculated, but the point 102b of the extension line L102 is calculated. ) And the point 101a of the extension line L101 are not connected. That is, the nth point on each extension line is first connected to the nth point of adjacent extension lines and starts to establish a connection line.

Here, the newly connected lines 102b to 101b cross the previously connected lines 102a to 101c, and compare the lengths of these two lines to determine one of these two lines. Accordingly, when the new lines 102b to 101b are shorter than the existing lines 102a to 101c, the existing lines 102a to 101c are canceled and the lines 102b to 101b are determined to form triangles (Δ102a, 101b and 102b). ) And triangles (Δ101b, 102b, 101c). On the other hand, when the new lines 102b to 101b are longer than the existing lines 102a to 101c, the lines 102a to 101c are determined, and triangles Δ102a, 101b and 101c and triangles Δ102a, 102b and 101c are used. ).

In this way, a connecting line and a triangle are defined between all the points of the extension line L101 and all the points of the extension line L102, and finally, the end point of the extension line L101 is connected to the end point of the extension line L102 unconditionally, thereby forming a half moon shape. Will generate

After that, the point distance measuring means divides the points on the next extension line L103 (not shown) while the distance measuring direction is changed by the angle of rotation (β) about the Z axis and then changed to the inclination angle α again. After setting, the above process is repeated to divide the triangular area and the half moon area.

When the point distance measuring means turns 360 degrees (or only 180 degrees) while turning around the Z axis by an arbitrary turning angle β, the reference area set in advance by calculating an area for each partitioned triangular area and its Compare the size. This is to prevent this, because the distance away from the origin 10 can increase the error as the size of the triangle area increases.

If it is determined that an arbitrary triangle area is larger than the reference area, as shown in FIG. 3, the coordinate value of the center of gravity point C of the triangle is obtained, and the inclination angle α corresponding to the coordinate value of the center of gravity point C is shown. ) And the point distance measuring means is adjusted to have a turning angle β to measure the distance toward the center of gravity C, thereby inspecting the elevation or depression of the center of gravity C. FIG. Accordingly, if the coordinate value of the center of gravity point (C) and the coordinate value of the actual measurement point coincide, the triangle is further divided into three smaller triangles based on the center of gravity point (C). The triangle is further divided into three smaller triangles.

As mentioned above, after partitioning the top surface of the load into predetermined regions, these divided triangular regions and the resulting half-moon-shaped region extend below the Z-axis to the bottom of the reservoir, thereby expanding the load into multiple blocks. Divide into

Another of the main features of the weighing method of the load in the storage according to the present invention is that the type of blocks that can come out when the load is blocked in two forms, that is, a triangular prism block having a triangular cross section, and a half moon shaped cross section It is divided into a half-moon columnar block having a, and separately provides a method of directly calculating the volume reflecting the height of the block by using the three-dimensional coordinate value of each vertex on the upper surface of the block according to the type of each block.

4 is a schematic diagram for explaining a method for obtaining the volume of a triangular prism block. Referring to this, the triangular prism block B1 has a triangular cross section, and the vertices on the upper surface of the block are p ₁ , p ₂ , and p ₃ , respectively, and are measured by point distance measuring means. P ₁ (x ₁ , y ₁ , z ₁ ), p ₂ (x ₂ , y ₂ , z ₂ ), p ₃ (x ₃ , y ₃ , z ₃ ), and these p ₁ , p ₂ , p The order of ₃ is determined by the height order (z ₁ > z ₂ > z ₃ ). When the lengths of the sides in the projection plane of this block are represented by a, b, and c, the volume of the triangular prism block B1 can be obtained by the following equation.

here,

,

,

,

,

이다.

to be.

The volumes of the triangular primitive blocks B1 are respectively calculated and these volumes are integrated.

Next, FIG. 5 is a schematic diagram for explaining a method for obtaining the volume of the half-moon columnar block. Referring to this, the half-moon columnar block B2 has a half-moon-shaped cross section, and the vertices on the upper surface of the block are p ₄ and p ₅ , respectively, and the coordinates measured by the point distance measuring means are p. ₄ (x ₄ , y ₄ , z ₄ ) and p ₅ (x ₅ , y ₅ , z ₅ ). If the radius of the reservoir is represented by r, the volume of the half-moon columnar block B2 can be obtained by the following equation.

The volumes of the semicolumnar blocks B2 are respectively calculated and these volumes are integrated.

Finally, the weight is calculated and finished by multiplying the total volume by the average density of the load. In this case, as shown in FIG. 1, if the cellar is a hopper-type cellar, a calculation is performed to subtract a predetermined volume value obtained by subtracting the volume of the truncated cone shape from the volume of the cylindrical shape with respect to the height H of the cellar again from the volume of the cylindrical shape. Can be.

As described above, according to the present invention, it is possible to more easily calculate the weight of the load in the storage using distance measurement using the point distance measuring means. Compared to the prior art, there is no error due to disturbance, so that the load can be more accurately measured, and various information such as the volume, height, and surface shape of the load can be obtained, thereby enabling more efficient inventory management.

1 is a perspective view of a reservoir.

2 is a view for explaining a method of partitioning the upper surface of the load into triangular regions and half moon-shaped regions.

3 is a view for explaining a method of further dividing when larger than the reference area of the triangular region.

4 is a schematic diagram for explaining a method for obtaining the volume of a triangular prism block.

5 is a schematic view for explaining a method for obtaining the volume of a half-moon columnar block.

Claims (6)

Dividing the load into a plurality of blocks using point distance measuring means; Obtaining a volume of each divided block; Adding the volumes of all blocks to obtain the total volume of the load; In the method of measuring the weight of the load in the storage, comprising: multiplying the total volume by the average density of the load; Dividing the load into blocks, Measuring the distance to the wall surface of the reservoir while turning the point distance measuring means horizontally at a constant speed, where the position of the point distance measuring means is set as the origin, and the line connecting the origin and the longest measured point Setting to the Y axis while setting a horizontal line perpendicular to the Y axis to the X axis, Measuring the height of the load meeting the Z axis by measuring the distance to the load by changing the measurement direction downward so that the point distance measuring means is perpendicular to the Y axis; Presetting an angle of inclination when the point distance measuring means is pivoted on an imaginary horizontal plane and an angle of inclination when an inclination is changed on an imaginary vertical plane and a reference area of a triangle; The upper surface of the load is divided by the pivot angle about the Z axis passing through the origin to set a radial extension line, and the extension line is further divided by the inclination angle from the Z axis to the wall surface of the reservoir. Setting a connecting line connecting each divided point to a divided point in an adjacent extension line, and dividing a plurality of triangular and half moon-shaped regions by these lines; and Measuring the weight of the load in the cellar, including dividing the entire load into a plurality of triangular prism blocks and a plurality of half-column blocks by extending each region defined by the extension line and the connecting line downwardly. Way. The method of claim 1, wherein the calculating of the volume of each divided block comprises: Measuring the distance from the origin to each point through the point distance measuring means, and using the trigonometric function to obtain a three-dimensional coordinate value of each vertex on the upper surface of each block; And calculating the volume reflecting the height of the block using the three-dimensional coordinate values of each vertex on the upper surface of the block. The method of claim 1, wherein dividing the load into blocks, Computing an area for each partitioned triangular area, comparing the reference area with its size, and when it is determined that the triangular area is larger than the reference area, obtains coordinates of the center of gravity of the triangle and corresponds to the coordinate value of the center of gravity. And storing the distance toward the center of gravity by adjusting the point distance measuring means to have an inclination angle and a turning angle, and further dividing the triangle into three smaller triangles based on the coordinate values of the actual measuring points. How to weigh your load. The method of claim 1, wherein partitioning the plurality of triangular regions comprises: Establish a connecting line that connects from each divided point on one extension line to the divided points on adjacent extension lines, calculate the length of each connecting line, and determine one connecting line that connects the shortest distance between the two crossing lines and cancel the other. How to weigh the load in the reservoir, characterized in that it comprises a step of. The method of claim 1, wherein the step of partitioning the half moon-shaped region, And the end points of the extension lines are connected to each other. The method of any one of claims 1 to 5, wherein the point distance measuring means is a laser distance sensor.

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