JPH08319087A - Position detecting method for cylindrical body - Google Patents

Abstract

PURPOSE: To inexpensively, reliably and accurately detect the coil position even if a pallet is changed in size, and a coil is also changed in position by scanning cylindrical bodies in the direction perpendicularly intersected with the center axes of the cylindrical bodies while light or ultrasonic waves are being irradiated to the cylindrical bodies to be detected. CONSTITUTION: Since a range finder 30 is mounted to a crab 22 of a crane 20, the crab 22 is moved to the direction 50. Therefore, a laser spot beam is moved as shown by a two-dot chain line 51. Namely, the whole of the range finder 30 formed out of a laser beam source 32 and a light receiving section 34 is swung so as to be moved over the curved line of the two-dot-chain line 51 while a laser beam 31 is being scanned in the direction of X. Thus whereever coils 10, 11 and 12 may be located on a pallet 13, scanning is performed over the whole of the coils, and data for their distance distribution is thereby stored in a microcomputer in a body detection device 40. The number of coils, size of each coil, width of each coil and the accurate center coordinates of each coil are then computed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical object detecting method for accurately detecting the positions of distant cylindrical objects using light or ultrasonic waves.

[0002]

2. Description of the Related Art Conventionally, a steelmaking coil (hereinafter referred to as a coil) produced in a steelmaking factory has a cylindrical shape, and when it is automatically transferred by an overhead crane, the position of the coil is accurately detected to It is necessary to lower the hanger. That is, of the plurality of coils carried into the coil yard by the truck,
In order to accurately guide the overhead crane onto the coil when automatically lifting the specified coil with the overhead crane,
It is necessary to accurately detect the position and size of the coil.
Therefore, as a conventional coil position detecting device, for example, there is an invention described in Japanese Patent Laid-Open No. 6-263382. This is to measure the position of the coil by detecting the position in the longitudinal direction and the position in the lateral direction of the pallet on which the coil is placed by a laser distance meter.

[0003]

However, in the coil position measurement in the conventional device, the longitudinal position of the pallet,
Since it is necessary to measure the coil position by detecting only the position in the lateral direction, it is a condition that the coil is placed at a predetermined position on the pallet. Therefore, when the size of the pallet is changed or the coil position on the pallet is changed, there is a problem that the coil position cannot be measured.

The present invention has been made in view of the above-mentioned drawbacks, and is inexpensive, highly reliable, and has a large pallet size.
The object is to be able to detect the coil position accurately even if the coil position changes.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and is directed to a central axis direction of one or a plurality of cylindrical objects to be detected and a trolley for mounting the cylindrical objects. The longitudinal direction forms a substantially right angle, while scanning the cylindrical object to detect light or ultrasonic waves from above these juxtaposed cylindrical objects, scanning in a direction substantially perpendicular to the central axis of the cylindrical object, The gist of the invention is to receive or receive reflected light or a reflected wave, collect distance distribution data up to a cylindrical object, and detect the position of the cylindrical object from the distance distribution data.

[0006]

[Operation] The direction of the central axis of the cylindrical object whose position is to be detected and the longitudinal direction of the carriage on which this cylindrical object is placed are substantially perpendicular to each other. While scanning the columnar object whose position located below is to be detected, scan in the direction substantially perpendicular to the central axis of the columnar object. Then, by receiving or receiving the reflected light or the reflected wave obtained by scanning while scanning in this way, the distance distribution data to the cylindrical object is collected,
Since the position of the cylindrical object is detected from the distance distribution data, the coil position can be accurately detected even if the size of the pallet or the coil position changes.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for detecting the position of a cylindrical object of the present invention will be described below with reference to the drawings. In the following description, the cylindrical object to be detected will be described by taking a coil as an example. As shown in FIGS. 1 and 3, a plurality of coils 10, 11 and 12 (or coils of the same diameter and length) having different coil diameters and lengths are placed on the pallet 13 via skids 14, 15 and 16. Then, it is carried into the coil yard and automatically lifted from above the pallet 13 by an overhead crane 20 arranged so as to travel and traverse above the coil yard. In this case, the central axis direction of the coils 10, 11, 12 and the longitudinal direction of the pallet 13 on which the coils are placed are substantially perpendicular to each other.

When the traveling direction of the overhead crane 20 is X, the transverse direction perpendicular to the traveling direction is Y, and the height direction is Z, the pallet 13 is carried in the Y direction. The coils 10, 11, 12 arranged on the pallet 13 are arranged in parallel on the pallet 13 with the central axes thereof oriented in the substantially X direction, and the skids 1 on the pallet 13 are arranged in parallel.
It is positioned and fixed by 4, 15, and 16.

The overhead crane 20 has a girder 21 traveling in the X direction, a club 22 disposed on the girder and traversing in the Y direction, and suspended from the club 22 in the up-and-down direction.
It is composed of a coil hanger 23 that moves up and down in the direction.

Reference numeral 30 denotes a range finder, which is, for example, a laser range finder and is integrally attached to the club 22 as shown in FIG. 1. A laser beam light 31 is irradiated below the laser range finder 30. It has a laser light source 32 and a light receiving portion 34 for receiving reflected light 33 which is reflected by the emitted laser light hitting the coils 10, 11, 12 and the like.
Therefore, the laser distance meter 30 can measure the distance distribution to each coil by the principle of the triangulation method. Here, the laser light 31 is configured to scan in the central axis direction of the coil to be detected (that is, the X direction). That is, the swing motor 35 swings the entire rangefinder 30 including the laser light source 32 and the light receiving unit 34, so that the laser light 31 can be scanned in the X direction. Here, the swing angle of the swing motor 35 can be measured by the encoder 36. 31 in FIG.
Reference numerals 0 and 311 denote left and right scan limits when the laser light 31 is scanned.

The club 22 has an object detecting device 4
0 is also mounted, and the object detection device 40 is connected to the rangefinder 30, and the distance distribution data up to the detection target coil obtained by scanning the rangefinder 30 is temporarily stored in the memory of the built-in microcomputer. After the completion of scanning, the data necessary for transportation by the crane 20, that is, the number of coils, the size of each coil, the width of each coil, the accurate center coordinates of each coil, and the like are calculated based on the data in the memory after scanning.

FIG. 5 shows a laser beam 31 in the rangefinder 30.
The scanning procedure by the crane 20 is shown. That is, since the rangefinder 30 is mounted on the club 22 of the crane 20, the club 22 is moved along the line 50 in the figure. Therefore, the laser spot light moves as shown by the chain double-dashed line 51 in this figure. That is, as the rangefinder 30 swings, it moves on the curve 51 while scanning in the X direction. By scanning in this way, the coils 10, 11,
It is possible to scan over all coils wherever 12 is on the pallet 13. That is, the distance distribution data on all the coils can be stored in the microcomputer in the object detection device 40.

FIG. 2 shows a part of the measurement result of the distance distribution stored in the microcomputer in the object detecting device 40 in the Y-Z direction plane. In this case, the scanning is continuously performed, but the distance distribution data is discretely sampled, so that the data in the circles in the figure are stored in the microcomputer. Since the distance in the height direction from the distance meter 30 to the ground 17 is fixed, the vertical axis of the figure shows the coil height distribution from the origin when the origin 0 is on the ground 17 by coordinate conversion. . Where 100 is the coil 10
, 110 is the part of the coil 11, 120 is the coil 1
2 part, 150 is part of skid 15, 160 is part of skid 16, 130 is part of pallet 13 and 170
Is the part of the ground 17 and the coordinates are converted, so 170
The height of the part is 0. In this case, skid 1
4, the right side 151 of the skid 15, the left side 1 of the skid 16
In 61 and the like, the reflected light of the laser is blocked by the coil and does not reach the light receiving portion 34, so that the distance cannot be measured.

The position in the X direction in the figure can be measured by an encoder and an encoder 36 (not shown) attached to the girder 21. The position in the Y direction is the club 22
It can be measured by an encoder (not shown) attached to.

FIG. 4 shows a part of the distance distribution data measurement result when the coil 10 is being scanned, in the X-Z direction plane. The circles indicate the measurement points.

Next, a method of calculating the number of coils, the size of each coil, the width of each coil, the accurate center coordinates of each coil, etc. by the microcomputer will be described based on these data.
2 and 4, by extracting a portion where the height value Z exceeds a predetermined constant value, data of a portion irrelevant to the coil surface (130, 150, 160, 170, etc.)
To delete.

Next, a method of calculating the center coordinates of each coil in the Y and Z directions will be described. The distance distribution data at three arbitrary points in the data 100 are (X1, Y1, Z1),
Let (X2, Y2, Z2) and (X3, Y3, Z3).
Set the center coordinates (Y and Z directions) of the coil 10 to (Y0, Z
0) and the radius is R,

[0018]

(Equation 1)

Therefore, from equations (4) to (5), Y0, Z0
The value of can be produced by simple arithmetic operations, and the result is as follows.

[0020]

(Equation 2)

By substituting this value into the equation (1) or (2), the radius R can be easily obtained. In this way, with other combinations of three data, Y0, Z0,
By obtaining the value of R and finally performing the arithmetic mean for each coil over the entire scanning range, the accurate center coordinates and size of each coil can be obtained.

Next, a method of calculating the center coordinates of the coil in the X direction and the width will be described with reference to FIG. For example, the central coordinate X0 in the X direction is obtained by arithmetically averaging the data on both end faces of the plurality of data 100 on the coil 10 in the X direction, and the width is obtained from the difference between the data in the X direction on both end faces.

The center coordinates and the width of other coils can be calculated in the same manner. In the above embodiment, the embodiment in which the entire rangefinder 30 is swung by the swing motor 35 is shown. The laser beam scanning method is not limited to this, and the second scanning method is shown in FIG. That is, the scanning motor 37 rotates the reflecting mirror 38 in the range of 380 to 381 to scan the laser light 31 emitted from the laser light source 32 in the range of 310 to 311. It is also possible to scan in the same manner by using a lens instead of the reflecting mirror 38 and utilizing refraction.

The above operation contents will be described with reference to FIG. (S1) A pallet 13 on which the coils 10, 11, 12 are placed based on a command from a host computer (not shown) or the like.
Enters the coil yard, club 2 of crane 20
The movement of 2 causes the rangefinder 30 to move to the distance distribution data sampling start position, and the following operation starts. (S2) The laser light of the laser rangefinder is turned on, and (S3) scanning is started. That is, the club 22 is traversed in the Y direction while scanning the laser light. At the same time, the distance meter 30 collects distance data. (S4) The distance data obtained at the same time is stored in the microcomputer 40. (S5) When the scanning is completed, (S6) the laser light is turned off, and (S7) based on the obtained distance distribution data, the coil width, the center coordinates and the radius of the coil, and the radius are doubled and the outside Calculate the diameter. (S8) The result is reported to the host computer or crane controller, and (S9) and above operations are stopped. In the above embodiment, the distance distribution data on the coil is 3
If the number of points is not reached, the scanning speed may be reduced, the scanning speed may be increased, or the scanning may be performed a plurality of times.

Needless to say, the same function can be obtained by using other light or ultrasonic waves instead of the laser light. In this case, the light receiving section 34 operates as the receiving section 34.

In the present embodiment, the range finder 30 and the object detecting device 40 are integrally attached to the club 22. However, the present invention is not limited to this and may be attached below the girder 21. , May be attached to other places. Further, in the present embodiment, the case of being mounted on the coil yard has been described as an example, but it goes without saying that the present invention can also be applied to the case of being mounted on the trailer.

[0027]

According to the method for detecting the position of a cylindrical object of the present invention, the center coordinates and outer diameter of each coil can be calculated by simple four arithmetic operations.
Since it is possible to accurately calculate and detect numbers and the like, it is ideal as a coil recognition device for cranes and the like that require high-speed processing and reliability. Also, although the description has been given with the distance in the height direction from the rangefinder to the pallet fixed, the distance in the height direction is not used directly in the calculation formula, so it is accurate even if the height of the pallet or skid changes. The effect is that the size and center coordinates of the coil can be calculated. Moreover, since the pallet itself has not been modified, it is not necessary to do anything such as the maintenance of the reflection plate installed on the pallet, which was necessary in the past. Further, there is an advantage that the coil position can be accurately recognized even when the size of the pallet changes or the coil position on the pallet changes.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of an object detection device used in the present invention.

FIG. 2 is a diagram showing an example of measurement of distance distribution data by a distance meter.

FIG. 3 is a side view of an object detection device used in the present invention.

FIG. 4 is a diagram showing an example of measurement of distance distribution data by a distance meter.

FIG. 5 is a diagram showing a scanning procedure of a rangefinder.

FIG. 6 is a diagram showing an optical or ultrasonic scanning device according to a second embodiment.

FIG. 7 is a diagram showing a flowchart of the present invention.

[Explanation of symbols]

 10, 11, 12 Coil 13 Pallet 14 Skid 20 Overhead crane 21 Girder 22 Club 23 Coil lifting device 30 Distance meter 31 Laser light 32 Laser light source 33 Reflected light 34 Light receiving part 35 Swing motor 36 Encoder 37 Scan motor 38 Reflector 40 Object detection apparatus

Claims (1)

[Claims] 1. A central axis direction of a columnar object to be detected in which one or a plurality of columnar objects are arranged in parallel with a longitudinal direction of a trolley on which the columnar object is placed is arranged at a substantially right angle,
Along the direction in which they are arranged in parallel, while scanning light or ultrasonic waves to the cylindrical object to be detected from above, scan in the direction substantially perpendicular to the central axis of the cylindrical object, and reflect the reflected light or reflected wave. A method for detecting a position of a cylindrical object, which comprises collecting distance distribution data up to the cylindrical object by receiving or receiving light, and detecting the position of the cylindrical object from the distance distribution data.