JPH06249638A - Measuring method for position of cylindrical object - Google Patents

Abstract

PURPOSE:To minimize the measurement error of a range finder as much as possible even when the cylindrical object measuring state of the range finder varies. CONSTITUTION:The height distribution data of a coil 10 and positional data of a laser range finder 42 which emits and receives laser light are prepared by moving the range finder 42 relatively to the coil 10 so that the range finder 42 can cross the coil 10 over a prefixed installing distance L0. Then the positional data are corrected so that the data can become the same value as a set distance and the position of the coil 10 is calculated based on the corrected positional data and height distribution data.

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 position of a columnar object which is placed at a remote position by using light or ultrasonic waves.

[0002]

2. Description of the Related Art As an example of a conventional method for measuring the position of a cylindrical object, a method for measuring the position of a coil produced in a steelmaking plant will be described. When the coil loaded into the coil yard is automatically hoisted by an overhead crane, it is necessary to accurately guide the overhead crane onto the coil. Therefore, as an apparatus for measuring the position of a coil, there is an invention described in, for example, Japanese Patent Laid-Open No. 3-162395. The coil position detecting device described in the above publication includes a laser light source, two scanning mirrors for converting spot light of the laser light source into one-dimensional slit light, and two TV cameras for photographing the slit light irradiated on the coil. Is installed in an overhead crane, the coil position is converted into a three-dimensional position coordinate based on this, and the coil position is calculated based on this.

[0003]

When the position of the coil is measured by the coil position detecting device, the coil position detecting device is moved. At this time, it is necessary to accurately grasp the moving distance. In addition, it is necessary to correct wear of the wheels of the truck used to move the coil position detecting device. That is, the lateral traveling wheels may be worn due to the aging of the overhead crane, or each wheel may slip with the rail, resulting in an error in the coil position measurement. However, the conventional device has not examined the correction for the above error.

The present invention has been devised in view of the above circumstances, and it is possible to constantly correct the position data actually measured by the distance meter so as to minimize the measurement error even if the measurement state of the distance meter changes. An object of the present invention is to provide a method for measuring the position of a cylindrical object.

[0005]

A method for measuring the position of a cylindrical object according to the present invention is to emit light or ultrasonic waves toward a cylindrical object and receive reflected light or ultrasonic waves reflected from the cylindrical object. In the method of measuring the position of a cylindrical object using a range finder that measures the distance to a reflection point, the range finder is relatively moved so as to cross the cylindrical object over a predetermined set distance, and the height of the cylindrical object is increased. The height distribution data of the cylindrical object and the position data of the range finder are measured by measuring the distance change and the distance moved by the range finder, and this position data is corrected so that it becomes the same value as the set distance. The position of the cylindrical object is calculated based on the position data and the height distribution data.

[0006]

Embodiments of the method of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a measuring system used in the method of the present invention, FIG. 2 is a side view of a main part of FIG. 1, and FIG. 3 is a flowchart showing the operation of the method of the present invention.

In the following description, a coil produced in a steelmaking factory as a cylindrical object will be described as an example. As shown in FIG. 1, the coil 10 is placed on a carriage 20 and carried into a coil yard 21, and is automatically lifted from the carriage 20 by an overhead crane 30. The traverse direction of the overhead crane 30 is Y, the traveling direction is X, and the height direction is Z.

The carriage 20 is carried in the Y direction. Trolley 20
The upper coil 10 has a central axis oriented substantially in the Y direction,
A plurality of them are juxtaposed in the Y direction, and each of them is positioned in the Y direction by the skid 13.

The coil 10 does not necessarily have a uniform diameter and width, but includes a large-diameter coil 11 and a small-diameter coil 12. The coils 10 have different widths in the Y direction, and the distance between adjacent coils is small. It can be different.

The overhead crane 30 includes a girder 31 that travels in the X direction, a club 32 that traverses in the Y direction, a coil suspension 33 that moves up and down in the Z direction, and a coil position measuring device 40 that measures the position of the coil 10. Has become

As shown in FIG. 2, the coil position measuring device 40 includes a laser range finder 42 mounted and housed in a body frame 41, a motor 43, a speed reducer 44, drive wheels 45, driven wheels 46, a position sensor 50, It includes an encoder 53 and a control unit 54 including a microcomputer.

The body frame 41 is formed in a substantially U-shape for holding the girder 31 on one side from below, and the laser range finder 42 is attached to the lower surface thereof. The laser range finder 42 projects the laser beam L downward, and the coil 10
The light emitting / receiving unit receives the reflected light reflected by.

The drive shaft of the motor 43 is a reduction gear 44 and a bearing 4.
7, a wheel shaft 48 pivotally supported by the main body frame 41 is connected, and a drive wheel 46 is attached to the wheel shaft 48.

The encoder 53 is connected via a bearing 47 to a wheel shaft 49 pivotally supported by the main body frame 41, and driven wheels 46 of the wheel 49 are attached thereto. Rails 34 and 35 protruding toward both outer sides are provided on the lower end surface of the girder 31 over substantially the entire length of the girder 31, and the driving wheels 4 are provided on the tread surface of the outer rail 34.
5 and driven wheels 46 are provided on the inner rail 35 so as to be rollable.

The position sensor 50 is, for example, a photo sensor including a light emitting portion and a light receiving portion, and includes two issuing portions 51.
A, 52A and one shared light receiving portion 51B. The light receiving portion 51B and the light emitting portion 51A form the first sensor 51, and the light emitting portion 52A forms the second sensor 5.
2 are configured.

The light emitting portions 51A and 51B are provided on the rail 34.
Are arranged on the lower surface in the vicinity of both ends with a predetermined set distance L0. The light receiving portion 51B is provided on the upper surface of the main body frame 41 so as to face the light emitting portions 51A and 52A. Then, when the coil position measuring device 40 moves on the rail 34 and the light receiving unit 51B receives the light from the light emitting units 51A and 52A, a light reception signal is input to the control unit 54. Further, the position signal of the laser range finder 42 is input to the control unit 54 as a pulse signal of the encoder 53 accompanying the rotation of the driven wheel 46.

The control unit 54 measures and calculates the height of the coil 10 and the position of the laser range finder 42 based on the received light signal and the pulse signal, and obtains the height distribution data of the coil 10 and the position data of the laser range finder 42. In addition to being created and stored, it also has an on / off control function for the motor 43.

Next, the operation of the coil position measuring device 40 will be described according to the method of the present invention with reference to FIG. First, the laser rangefinder 4 owned by the encoder 53
The position data of 2 is once cleared (see S1). The motor 43 is driven by the command of the control unit 54, the laser rangefinder 42 starts moving in the Y direction (see S2), and the light receiving unit 51B of the position sensor 50 detects the light emitting unit 51A of the first sensor 51 ( See S3).

Then, the laser rangefinder 42 is connected to the coil 10
The measurement of the height distribution of the
Starts position data measurement of the laser rangefinder 42 (S4
reference). Both the height distribution data of the coil and the position data of the laser rangefinder 42 are calculated by the control unit 54,
Stored in memory.

Next, when the light receiving section 51B detects the second sensor 52 (see S5), the measurement of the height distribution data of the coil 10 is completed and the position data of the laser rangefinder 42 is measured at the same time. Completed (see S6). It goes without saying that the measurement results are calculated and stored by the control unit 54 in accordance with the above.

The control unit 54 calculates the distance L between the first sensor 51 and the second sensor 52 from the position data of the laser rangefinder 42 between the first sensor 51 and the second sensor 52. (See S7).

On the other hand, α = L0 / L is calculated by using the set distance L0 of both the first and second sensors (see S8).

If the driving wheels 45 and the driven wheels 46 are not worn and there is no slip between the rails 34 and 35 and the wheels 45 and 46, α = 1. When α ≠ 1, (S
9), the position data of the laser rangefinder 42 in the memory is multiplied by α to correct the position data (S).
10).

When the correction is completed (see S11), the controller 54 calculates the size and position of the coil 10 based on the position data of the laser rangefinder 42 and the height distribution data up to the coil 10 (see S12). .

According to the present embodiment, the position data of the laser range finder 42 can be constantly corrected, so that even if the wheels wear or slip between the wheels and the rail due to aging, the position data can be accurately corrected. Can be measured.

In this embodiment, the laser rangefinder 4
Since the position measurement of No. 2 uses the driven wheels 46, there is almost no slippage with the rail 35. Generally, the laser range finder 42 slips during accelerated movement, but if the first sensor 51 is provided at a position where the measurement is started and the laser range finder 42 reaches a constant speed after the movement starts, the influence of the slip does not appear.

Further, in the present embodiment, the range finder uses a laser, but it may be a range finder using other light or ultrasonic waves. Further, in the present embodiment, the encoder is used for detecting the position of the range finder, but it goes without saying that an inductive wireless system, a magnetic sensor or the like may be used. Further, the position sensor is not limited to the photo sensor as long as it has the same function.

[0028]

As described above, according to the method of the present invention, the distance meter is moved so as to traverse the cylindrical object, the height distribution data of the cylindrical object and the position data of the distance meter are measured, and preset. The position data is corrected so as to have the same value as the moving distance of the distance meter, and the position of the cylindrical object is calculated based on the corrected position data and the height distribution data.

Since the position data of the range finder can be constantly corrected as described above, accurate measurement can be performed even if wheel wear or slippage occurs between the wheel and the rail due to aging. Therefore, the error in measuring the position of the coil can be made extremely small, so that it is possible to automatically and safely lift the cylindrical object by an overhead crane or the like.

[Brief description of drawings]

FIG. 1 is a front view of a measurement system used in the present invention.

FIG. 2 is a side view of a main part of FIG.

FIG. 3 is a flowchart showing the operation of the method of the present invention.

[Explanation of symbols]

 10 coil 20 trolley 30 overhead crane 31 girder 32 club 40 coil position measuring device 42 laser range finder 50 position sensor 51 first sensor 52 second sensor 53 encoder 54 control unit

Claims (1)

[Claims] 1. A cylindrical object using a rangefinder that emits light or ultrasonic waves toward a cylindrical object, receives reflected light or ultrasonic waves reflected from the cylindrical object, and measures the distance to a reflection point. In the position measurement method, the relative distance meter is relatively moved so as to cross the cylindrical object over a predetermined set distance, and the height change of the cylindrical object and the moved distance of the distance meter are measured to measure the cylindrical object. Create height distribution data and position data of a rangefinder, correct this position data to be the same value as the set distance, and based on this corrected position data and the height distribution data, A method for measuring the position of a cylindrical object, characterized in that the position is calculated.