JPH0886610A - Method for detecting columnar object - Google Patents

Abstract

PURPOSE: To provide a simple columnar object detecting method with high reliability without requiring maintenance for a carriage for the method, by operating the width and central point in a scanning direction of a columnar object from a position where distance distribution data change largely. CONSTITUTION: In order to detect coils 10, 11, a club 22 is moved in Y direction to scan a laser light 31 all over the coils 10, 11 on a pallet 12 and a reflecting light 33 is received at a photodetecting part 34. An operating part 40 temporarily stores, in a microcomputer, distance distribution data of each coil obtained through the scanning. After completing the scanning, data necessary for transporting the coil by a ceiling crane 20, namely, the size, width and correct central coordinates, etc., of each coil are operated. Similarly, central coordinates and a value of the radius of each coil are obtained in a different combination of three distance distribution data. An arithmetic mean of the values obtained all over the scanning area is detected for each coil to obtain the correct central coordinates and size of each coil 10, 11.

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 detecting the positions of distant cylindrical objects using light or ultrasonic waves.

[0002]

2. Description of the Related Art As one of conventional methods for detecting a cylindrical object, a steelmaking coil (hereinafter referred to as a coil) produced by rolling a steel sheet into a roll at a steelmaking factory is used when automatically conveyed by an overhead crane. A method of detecting the position of the coil will be described.

[0003] When a coil carried into a coil yard by a truck is automatically lifted by an overhead crane, it is necessary to accurately detect the position and size of the coil in order to accurately guide the overhead crane onto the coil. As a conventional coil position detecting device therefor, for example, Japanese Patent Laid-Open No.
There is an invention described in Japanese Patent No. 165006. This is a method in which the light emitted from the projector attached to the coil position detecting device is reflected by the reflection tape attached to the trolley to the CC.
The position of the coil is measured by a D camera and image processing.

[0004]

However, in the coil position measuring method by image processing in the conventional coil position detecting device, the measuring device is complicated and expensive. Further, when the surface of the coil is shining, the coil cannot be clearly distinguished from the background, and there is a possibility that measurement cannot be performed. In addition, it is necessary to attach a reflective tape to the trolley as a guideline for measuring the coil diameter, but there is also a point that maintenance is troublesome because it becomes dirty or peels off and malfunctions. The present invention was created in view of the above circumstances, and an object thereof is to provide a cylindrical object detection method that is a simple method, has high reliability, and does not require maintenance for a carriage.

[0005]

A cylindrical object detecting method according to the present invention scans while irradiating a cylindrical object to be detected with a plurality of light or ultrasonic waves of three or more, and scanning from the cylindrical object. By collecting the reflected light or reflected wave to reflect, to create a distance distribution data to the cylindrical object, in the cylindrical object detection method for detecting the position of the cylindrical object from the distance distribution data, the distance distribution The width of the cylindrical object and the center point in the scanning direction are calculated from the position where the data greatly changes, and the diameter of the cylindrical object and the diameter of the cylindrical object are calculated based on three data selected arbitrarily from the distance distribution data. The feature is that the central coordinates are arithmetically operated.

[0006]

The width of the cylindrical object and the center point in the scanning direction are calculated from the position where the distance distribution data obtained by scanning the cylindrical object with light changes greatly. Then, the coordinates of the three points are calculated based on the data of three points arbitrarily selected from the distance distribution data, and the diameter and center coordinates of the cylindrical object are obtained by four arithmetic operations based on these coordinate values.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cylindrical object position detecting method according to the present invention (hereinafter referred to as the present invention method) will be described below with reference to the drawings.

FIG. 1 is a front view for explaining the principle of the method of the present invention, FIG. 2 is a side view showing an embodiment of a cylindrical object detecting device used in the present invention, FIG. 3 is the same front view, and FIG. 4 is a circle. FIG. 5 is a flow chart for explaining the operation of the method of the present invention, in which a columnar object and distance distribution data are compared.

In the following description, the cylindrical object to be detected will be described by taking a coil as an example as in the above case. The cylindrical object detection device 50 used in the method of the present invention is mounted on the overhead crane 20 and includes a range finder 30 and a calculation unit 40. As shown in FIGS. 2 and 3, the coils 10 and 11 are placed on a pallet 12 and carried into a coil yard, and are automatically lifted from the pallet 12 by an overhead crane 20.

It is assumed that 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. Pallet 1
2 is loaded in the Y direction, and the coils 10 on the pallet 12 are
11 are juxtaposed on the central axis of the pallet 12 with their central axes oriented in the substantially Y direction, and each of them is positioned and fixed by a skid 13 on the pallet 12. The overhead crane 20 includes a girder 21 that travels in the X direction, a club 22 that traverses in the Y direction, and a coil suspension 23 that moves up and down in the Z direction.

The range finder 30 is, for example, a laser range finder and is integrally attached to the club 22.
A plurality of laser light sources 32 for irradiating a, 31b, 31c, 31d, 31e (hereinafter, collectively referred to as reference numeral 31).
a, 32b, 32c, 32d, 32e (hereinafter collectively referred to as reference numeral 32), the irradiated laser light 31 is the coil 1
It is provided with a light receiving portion 34 (all of which are collectively denoted by reference numerals) that receives the reflected light 33 reflected by 0, 11 and the like. The laser light sources 32 are arranged in the X direction with a predetermined equidistant spacing D.

The arithmetic unit 40 has a built-in microcomputer and is electrically connected to the light receiving unit 34 via a flexible cable (not shown). The calculation unit 40 has a function of calculating and storing the distances to the coils 10 and 11 according to the principle of the triangulation method based on the angle at which the laser light 31 and the reflected light 33 intersect.

To detect the coils 10 and 11, the club 22 is traversed in the Y direction and the laser beam 31 is applied to the pallet 12.
Scan over the top coils 10, 11. The reflected light 33 reflected by the coils 10, 11 and the like is received by the light receiving unit 34. The arithmetic unit 40 temporarily stores the distance distribution data to each coil obtained by the scanning in the memory of the microcomputer.

After the completion of scanning, the data necessary for carrying the coils by the overhead crane 20 based on the data in the memory, that is, the number of coils, the size of each coil, the width of each coil,
Accurate center coordinates of each coil are calculated. The result of this calculation is reported to the host computer (not shown) or the controller of the overhead crane.

In the lower part of FIG. 4, among the measurement results of the distance distribution stored in the microcomputer in the arithmetic unit 40, the laser beam 3
1c is illustrated. In the figure, since the distance L in the height direction from the distance meter 30 to the pallet 12 is constant, the vertical axis in this figure indicates the coil from the origin when the origin O is the upper surface of the pallet 12 by coordinate conversion. The height distribution is shown. Here, 100 and 110 are portions of the width of the coils 10 and 11, 130 is a portion of the skid 13, and 120 is a portion of the pallet 12. Since the coordinates are converted, the height of the portion 120 is zero.

Further, since the outer portion 121 of the pallet 12 cannot measure the distance, the height is set to zero in the memory of the microcomputer. Reference numeral 131 in the drawing denotes a portion that cannot be measured because the reflected light 33 enters the shadows of the coils 10 and 11, and the height is also set to zero. The position of each part such as the coil in the Y direction in this figure can be easily measured by an encoder or the like (not shown) attached to the club 22.

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. in the microcomputer will be described based on these distance distribution data. In FIG. 4, the number of coils, the widths W1 and W2 of each coil, and the center coordinates in the scanning direction, that is, the Y direction, can be calculated by extracting the portion where the value of the coil height exceeds a predetermined constant value. it can.

Next, a method of calculating the diameter of each coil and the center coordinates in the X and Z directions will be described with reference to FIG. Loading direction Y here
The central axis of the coil parallel to the Y axis is the Y axis, the central axis of the coil orthogonal thereto is the X axis, and the height direction is the Z axis.

Laser beams 31a, 31b on the coil 11
31c, 31d, 31e irradiated points P, Q, R, S,
The value of each height Z of T is measured by the range finder 30 as already described and is known. The X-axis coordinate position of each point is known because the laser light sources 32 are arranged at a predetermined distance D. That is, the laser light 31
a, 31b, 31c, 31d, 31e on the Y-axis, P, Q, R, S, T coordinates (X ₁ , Z ₁ ), (X ₂ ,
Z ₂ ), (X ₃ , Z ₃ ), (X ₄ , Z ₄ ), (X ₅ , Z
₅ ), is known.

In FIG. 1, it is assumed that the laser light 31C passes through the origin O coordinate (0, 0) on the pallet 12 in the X direction, and three arbitrarily selected data among the coordinate data, that is, the point P. The coordinates (X ₁ , Z ₁ ), the coordinates of the point R (X ₃ , Z ₃ ), the coordinates of the point S (X ₄ , Z ₄ ), are used, and the coordinates of the points Q and T (X ₂ , Z 3 ₂ ), (X ₅ ,
The coordinates of Z ₅ ), are not shown. The coordinates of the origin O are (0,0).

The coordinates of the center C of the coil 11 are (X ₀ ,
Z ₀ ), and the radius of the coil 11 is r, the formula 1 is obtained.

[0022]

[Number 1] ^{_{(X 0 -X 1) 2 +}} (Z 0 -Z 1) 2 = r 2 (X 0 -X 3) 2 + (Z 0 -Z 3) 2 = r 2 (X 0 -X 4 _{^{) 2 + (Z 0 -Z 4}} ) 2 = r 2

The expression of the expression 2 is obtained from the expression of the expression 1.

[0024]

2X ₀ (X ₁ −X ₃ ) + 2Z ₀ (Z ₁ −Z ₃ ) = A 2X ₀ (X ₁ −X ₄ ) + 2Z ₀ (Z ₁ −Z ₄ ) = B where A = X _{1 ^{2 -X 3 2 + Z 1 2}} -Z 3 2 B = X 1 2 -X 4 2 + Z 1 2 -Z 4 2

The expression of the expression 3 is obtained from the expression of the expression 2.

[0026]

(Equation 3) However, X ₀ : X coordinate of the central position of the cylindrical object Z ₀ : Z coordinate of the central position of the cylindrical object X ₁ : X coordinate of the irradiation position of the arbitrarily selected first laser beam on the cylindrical object Z ₁ : Z coordinate of the irradiation position of the cylindrical body of the first laser beam arbitrarily selected X _3: X-coordinate of the irradiation position of the cylindrical body of the second laser beam arbitrarily selected Z _3: arbitrarily selected second Z-coordinate of the irradiation position of the cylindrical object of the laser beam X _4: the irradiation position of the cylindrical body of the third laser beam arbitrarily selected X coordinate Z _4: third randomly selected Z coordinate of the irradiation position of the laser beam on the cylindrical object

Substituting the equation of equation 3 into equation 1, r is obtained.

In this way, the center coordinates (X ₀ , X ₀ ,
The accurate center coordinates and size of each coil can be obtained by obtaining the values of Z ₀ ) and the radius r, and finally performing the arithmetic mean of the obtained values over the entire scanning range for each coil.

Next, the above operation contents will be described with reference to FIG. (1) When the pallet 12 on which the coils 10 and 11 are placed enters the coil yard based on a command from a host computer (not shown), the crane 20 causes the range finder 30 to start collecting distance distribution data up to the pallet 12. After that, the following operation starts (S1).

(2) The laser beam of the rangefinder is turned on (S
2) The scanning is started (S3). That is, the club 22
The distance meter 30 collects the distance data while traversing in the Y direction, and at the same time stores the distance data in the calculation unit 40 (S4).

(3) When the scanning is completed (S5), the laser light is turned off (S6), and the calculation unit 40 first calculates the coil width based on the obtained distance distribution data (S7).

(4) Subsequently, the center coordinates and radius of the coil,
The radius is doubled to calculate the outer diameter (S8). (5) Report the calculation result to the host computer or crane controller (S9), and stop the above operation (S10).

In the embodiment shown in FIGS. 2 and 3, the same function can be obtained by using other light or ultrasonic waves instead of the laser light. In this case, it goes without saying that the light receiving section 34 operates as the receiving section 34. Although the distance meter 30 is integrally attached to the club 22 in this embodiment, the present invention is not limited to this, and the distance meter 30 may be attached to the girder 21 so as to be traversable or attached to another place. May be.

[0034]

As described above, according to the method of the present invention, three or more light beams or ultrasonic waves are radiated to a cylindrical object to be detected while scanning, and reflected light reflected from the cylindrical object or In the cylindrical object detection method of creating the distance distribution data to the cylindrical object by collecting the reflected wave and detecting the position of the cylindrical object from the distance distribution data, the distance distribution data largely changes. From the position, the width of the cylindrical object and the center point in the scanning direction are calculated, and the diameter and center coordinates of the cylindrical object are calculated based on three arbitrarily selected data in the distance distribution data. I am trying to do it.

Therefore, since the center coordinates and outer diameter of each coil can be accurately calculated by a simple method, high-speed processing,
It is ideal as a coil recognition device for automatic cranes that require reliability.

Further, since the distance L in the height direction from the distance meter 30 to the pallet 12 is not used in the calculation formula, the coil size and center coordinates are accurately calculated even if the height of the pallet changes. There is an effect that can be done. Further, since the pallet itself does not require any work such as attaching a reflection tape, it is very convenient because there is no need to perform maintenance as in the conventional case.

[Brief description of drawings]

FIG. 1 is a front view illustrating the principle of the method of the present invention, which is a drawing according to the present invention.

FIG. 2 is a side view showing an embodiment of a cylindrical object detection device used in the present invention.

FIG. 3 is a front view of the same.

FIG. 4 is an explanatory diagram of comparison between a cylindrical object and distance distribution data.

FIG. 5 is a flowchart explaining the operation of the method of the present invention.

[Explanation of symbols]

 10 Coil 11 Coil 12 Pallet 20 Overhead Crane 21 Girder 22 Club 23 Coil Suspension Tool 30 Distance Meter 31 Laser Light 32 Laser Light Source 33 Reflected Light 34 Light Receiving Section 40 Computing Section 50 Cylindrical Object Detection Device

Claims (1)

[Claims] 1. A method of scanning while irradiating a cylindrical object to be detected with a plurality of three or more lights or ultrasonic waves, and collecting reflected light or a reflected wave reflected from the cylindrical object, Create distance distribution data to a cylindrical object,
In a cylindrical object detection method for detecting the position of the cylindrical object from the distance distribution data, the width of the cylindrical object and the center point in the scanning direction are calculated from the position where the distance distribution data greatly changes, and the distance distribution is calculated. A cylindrical object detecting method, characterized in that the diameter and center coordinates of the cylindrical object are calculated based on three arbitrarily selected data.