JPH112508A - Position detecting device for lifting load - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position detecting device for a lifting load, contributing to a reduction in the cycle time of unloading of the lifting load in an automatic warehouse. SOLUTION: An infrared stroboscope 16 is provided to emit light toward a photographic area. A detector 17 outputs a detected value for determining a tilt angle of a lifting gear. An image processing part 21 detects the position of a lifting load by processing an image involving an infrared region photographed with a TV camera 15. A controller 20 estimates the turning angle of a rope from the command value of the moving speed of a trolley and from the value detected by the detector 17, then determines the position of the lifting load from the contour of the lifting load which is obtained by the image processing part 21 on the basis of a signal from a detector 27 for the traveling position of an overhead traveling crane and a signal from a traverse position detector 26, and further corrects the position of the lifted part of the lifting load on the basis of the result estimated and a signal from a height position detector 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting the position of a suspended load in a warehouse or a yard where the suspended load is transported by an overhead crane, and more particularly to a position detection of a suspended load suitable for an automatic warehouse that handles rolled coils as a suspended load. Related to the device.

[0002]

2. Description of the Related Art Recently, warehouses for products or semi-finished products, such as steelworks, are being automated to save labor. As an example of such an automatic warehouse, for example, in an automatic warehouse for rolling coils (hereinafter, referred to as coils),
The coil is transported by an overhead crane. The position of the coil is controlled and set in the traveling direction and the traversing direction of the overhead crane in the automatic warehouse. The overhead crane has a hanging tool, and a traveling operation and a traversing operation, and an automatic operation of lifting and hanging are performed under the control of the control device. The overhead crane has a girder running in the longitudinal direction of the automatic warehouse, a trolley traversing along the girder, and a hanger suspended on the trolley via hoisting and lowering ropes. Therefore, the traveling operation is an operation for moving the automatic warehouse along the longitudinal direction, and the traversing operation is an operation for moving the automatic warehouse along the width direction.

For example, when unloading one coil from an automatic warehouse, a command signal indicating the position of the coil to be unloaded is given to a control device. The position of the coil to be carried out is represented by a position in the traveling direction and a position in the traversing direction. Upon receiving the command signal, the control device calculates a moving acceleration command value for the girder and the trolley. The moving acceleration command value is information for accelerating at a constant acceleration after a predetermined time from the start, and then decelerating at a constant deceleration to stop at a target position.

According to the above command signal, the trolley is moved to a position almost directly above the coil from which the lifting device is to be carried out.
In order to hang the hanger on the hung portion of the coil, that is, on the hole at the center of the coil, it is necessary to further position the hanger.
In order to perform such positioning, a coil position detecting device is provided. This type of position detection apparatus generally uses image processing by a television camera, and the television camera is mounted on a trolley facing downward. The image processing extracts an outline of the coil by processing an image signal obtained by imaging the coil immediately below. Then, the center of the extracted contour is determined to be the coil center, and the hanging tool is matched therewith for handling.

[0005]

By the way, in this position detecting device, it is necessary to put a coil to be carried out into the field of view of the television camera. However, since the TV camera is mounted on the trolley, the TV camera must be positioned horizontally from the hanger so that the hanger does not interfere with imaging and the TV camera and the hanger do not overlap in the vertical direction. Need to be shifted. In this case, stop the trolley with the TV camera positioned almost directly above the coil,
After imaging the coil and detecting the position, in order to handle the coil further, the trolley is moved at a very slow speed by the horizontal displacement between the TV camera and the hanger to align the hanger. There is a need to do.

In such a position detecting device, the position of the hanger is adjusted after the position of the coil is once detected.
There is a problem that time is required for positioning, and a cycle time for carrying out the coil becomes long. In addition, the television camera is easily affected by external light, for example, light from a window, and it takes time to determine the contour of the coil. .

An object of the present invention is to provide a device for detecting a position of a suspended load which contributes to shortening of a cycle time of unloading.

Another object of the present invention is to provide an apparatus for detecting a position of a suspended load which is hardly affected by external light.

[0009]

According to the present invention, there is provided a control device having a hanger for controlling travel and traverse based on a command signal from a host device and a moving speed command value calculated based on the command signal. In the overhead traveling crane, the traveling direction of the overhead crane, the position of the suspended load is managed and placed in the traversing direction, and the suspended load position detection device detects the position of the suspended load by image processing, A traveling position detector for detecting a traveling position of the crane and outputting a traveling position detection signal; a traveling position detector for detecting a traveling position of the overhead crane and outputting a traveling position detection signal; A height position detector for detecting the height position of the fixture and outputting a height position detection signal, a television camera provided downward on the hanging fixture, and capable of capturing an image up to an infrared region; turtle An image processing unit for detecting the position of the suspended load image by processing from, provided in the load block,
An infrared strobe that emits light toward a suspended load; and a detector provided on the hanging device or a rope suspending the device to detect an inclination angle of the hanging device. Estimating and calculating the swing angle of the rope from the speed command value and the detection value of the detector, and calculates the position of the suspended load obtained by the image processing unit based on the travel position detection signal and the traverse position detection signal. Discriminating and further correcting and calculating the position of the portion to be lifted predetermined on the load based on the result of the estimation calculation and the height position detection signal.

It is preferable that the emission of the infrared strobe is synchronized with the timing of image input to the image processing unit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. In this embodiment, description will be made on the assumption of an automatic coil storage. Referring to FIGS. 2 and 3, in an automatic warehouse for coils, coils 30 are transported by overhead crane 10. The coil 30
The positions of the overhead crane 10 in the traveling direction and the traversing direction are controlled and set in the automatic warehouse. The overhead crane 10 includes a girder 11 traveling in the longitudinal direction of the automatic warehouse (indicated by a two-way arrow X in FIG. 3) and a trolley traversing (indicated by a two-way arrow Y in FIG. 2) along the girder 11. The trolley 12 includes a hoisting device 14 suspended by a hoisting and lowering rope 13. The overhead crane 10 performs a traveling operation and a traversing operation, and an automatic operation of lifting and suspension under the control of a control device described later. Here, the traveling operation is an operation for moving the automatic warehouse along the longitudinal direction (arrow X), and the traversing operation is an operation for moving the automatic warehouse along the width direction (arrow Y). It is.

The hanging member 14 is hung by the rope 13 at two points in a direction perpendicular to the transverse direction of the trolley 12 in order to prevent its rotation. The coil position management is performed by drawing a grid in the longitudinal direction and the width direction of the automatic warehouse, placing the coil at each intersection, and expressing the position of the coil by the distance in the X direction and the distance in the Y direction. ing.

Referring also to FIG. 4, the hanging member 14 has two hooks 14-1 in a direction perpendicular to the transverse direction of the trolley 12. These hooks 14-1 are driven so as to be able to approach and separate from each other, and their tips are connected to the center hole 3 of the coil 30.
You can get into 0-1 and hook it. For this reason, the coil 30 is always placed so that the hole 30-1 faces the X direction shown in FIG.

In this embodiment, a television camera 15 having an imaging band up to the infrared region is mounted on the hanging member 14, and an infrared strobe 16 is provided adjacent to the television camera 15. The reason why the television camera 15 having an imaging band up to the infrared region is used is that external light enters through a window on a ceiling or a side wall of an automatic warehouse and causes disturbance during image processing. The N ratio can be improved. Also,
The infrared strobe 16 is provided to capture the coil as a still image while the trolley 12, ie, the television camera 15, is moving (during deceleration). That is, as will be described later, the emission of the infrared strobe 16 and the television camera 15
Synchronizes the timing of image input to the image processing unit.

By the way, usually, this kind of overhead crane 1
At 0, an electric anti-sway device for the hanging tool is provided, but it is difficult to completely eliminate the run-out. In particular, trolley 1
2 is slowed down at the time of stop.
4 is more forward than the trolley 12, and tends to be inclined. Such an inclination causes an error in detecting the center position of the coil 30, and therefore requires correction. In this embodiment, the accelerometer or the rope 13
An inclinometer is provided as a detector 17 to detect the inclination of the hanger 14.

The position detecting device according to the present embodiment will be described with reference to FIG. As for the image signal of the coil 30 obtained by the television camera 15, the reflected light of the infrared strobe 16 of the coil 30 is extracted by the image processing in the image processing unit 21. This extraction signal is sent to the control device 20.
The control device 20 calculates a moving speed command value based on a command signal from a higher-level device (not shown).
a, 22b, 22c through the traversing device 23 (trolley 1).
2), a traveling device 24 (travel of the girder 11), and a hoisting / lowering device 25 (up and down of the hoisting device 14). For these controls, the position detecting device further detects a traversing position of the trolley 12 and outputs a traversing position detection signal, and a traveling position of the girder 11 by detecting a traveling position of the girder 11. A traveling position detector 27 for outputting a signal and a winding height detector 28 for detecting a height position of the hanging device 14 and outputting a height position detection signal are provided.

The control device 20 estimates and calculates the inclination angle of the hanging member 14 from the moving speed command value and the detection value of the detector 17, and performs image processing based on the traveling position detection signal and the traverse position detection signal. The position of the coil 30 is determined from the outline of the suspended load obtained by the section 21. Further, the hole 30-1 of the coil 30 is determined based on the estimation calculation result and the height position detection signal.
Is corrected and calculated. The control device 20 also synchronizes the light emission timing of the strobe 16 with the timing of capturing an image into the image processing unit 21.

Hereinafter, the control operation of the control device 20 will be described. When unloading the coil from the automatic warehouse, the operator specifies the coil to be unloaded to the host device.
The host device determines the position of the designated coil, and outputs a signal indicating the position, that is, a signal indicating the position in the X direction and the position in the Y direction to the control device 20. Upon receiving the command signal, the control device 20 plans a traveling and traversing route to the designated coil, and calculates an acceleration start timing, an acceleration continuation time, and a deceleration start timing in consideration of the steady rest until reaching the coil. I do. And
The overhead crane 10 is started and the traverse position detector 26 is started.
Based on the detection signal of the traveling position detector 27, while operating the electric steady rest control, the coil approaches the coil specified by the traveling and traversing operation, and starts the deceleration operation of the positioning in consideration of the steady rest. In planning the traveling to the designated coil and the traversing route, the designated coil is always located in front of the television camera 15.

When the control unit 20 determines that the vehicle has entered the deceleration region and has entered a predetermined range from the position of the coil designated by the traverse position detection signal, the control unit 20 causes the infrared strobe 16 to emit light and It is instructed to capture an image from the television camera 15 at the timing of leverage. Here, when the infrared strobe 16 is caused to emit light in the state of FIG. 5, a linear reflected light corresponding to the width of the coil 30 at the point P1 enters the television camera 15. This is because the light incident on the point P1 is reflected directly to the television camera 15 side, and diffusely reflected in other areas, and the television camera 1
This is because light is hardly incident on No. 5. The image processing unit 21 extracts a linear image signal specifying the coil 30 from the captured image signal, and outputs the extracted linear image signal to the control device 20. The control device 20 calculates the center position of the coil from the input linear image signal of the coil.

In this calculation, a first correction described below is performed. The capture of the image signal from the television camera 15 described above is performed in a positional relationship as shown in FIG. The television camera 15 and the infrared strobe 16 are installed at the same height. In this case, the extracted linear image signal of the coil 30 is located at the point P1. That is, the reflected light from the coil 30 becomes linear in the width direction (the direction of the central axis) of the coil 30 at the position of the point P1. The control device 20 calculates a horizontal distance x from this point P1 to a point P1 from a line segment immediately below the television camera 15. However, the point P1 is shifted from the center of the actual coil 30 by the distance C1. In order to calculate the distance C1 as a correction value, the control device 20 performs a correction operation using the following equation (1).

[0021]

(Equation 1) Note that R is the radius of the coil 30 known in advance, and d is the value obtained by subtracting the radius R of the coil 30 from the height of the hanging member 14 obtained by the winding height detector 28. The distance D1 is a horizontal distance between the hook 14-1 of the hanging tool 14 and the television camera 15.

The control device 20 adds the correction value C1 to the horizontal distance x calculated in this way, and determines the resulting value (x + C1 + D1) as the distance to be moved from the image capturing position. The trolley 12 is moved by that distance. In this movement, the positioning accuracy can be improved by repeatedly performing the above-described correction operation.

By the way, as described above, the trolley 12
Decelerates at the time of stopping, the inertia
Becomes more forward than the trolley 12, and tends to be inclined. If there is such an inclination, the hanger 14 will not be in the state shown in FIG. A second correction operation considering this will be described with reference to FIG.

In FIG. 6, it is assumed that the swing angle of the hanging member 14 is θ. In this case, when the control device 20 receives a signal indicating the shake angle θ based on the detection signal from the detector 17,
The correction value C2 is calculated by performing the calculation according to the following equation.

C2 = L · sin θ where L is the rope 13 suspended from the trolley 12.
Is the length of

The controller 20 subtracts the value obtained by subtracting the correction value C2 from the value (x + C1 + D1), and
The trolley 12 is moved as a horizontal distance from to the center of the coil 30.

The detector 17 may be an inclinometer provided on the rope 13 to determine the swing angle θ of the hanging member 14 from the inclination angle of the rope 13. Further, by providing an accelerometer on the hanging member 14, the calculation of the correction value C2 can be performed. The method of calculating the deflection angle θ by the accelerometer can be obtained from the accelerometer and the rope length L, which are conventionally known techniques.

As is apparent from the above description, in the present embodiment, the image of the coil is captured while approaching the designated coil and the position of the coil is detected. There is no. Moreover, since an image in the infrared region is used for image processing using a strobe in the infrared region, image processing with a high S / N ratio can be performed without being affected by external light.

[0029]

As described above, according to the present invention, it is possible to shorten the cycle time for carrying out a suspended load, and to provide a position detecting device for a suspended load which is hardly affected by external light. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a suspended load position detecting device according to the present invention.

FIG. 2 is a diagram showing a configuration of an overhead crane of an automatic warehouse to which the present invention is applied.

FIG. 3 is a view of the overhead crane shown in FIG. 2 as viewed from the direction of arrow A in FIG. 2;

FIG. 4 is an enlarged view showing a positional relationship between the hanger and the coil in FIG. 3;

FIG. 5 is a diagram for explaining a first correction operation in the present invention.

FIG. 6 is a diagram for explaining a second correction operation in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Overhead crane 11 Girder 12 Trolley 13 Rope 14 Hanger 14-1 Hook 15 TV camera 16 Infrared strobe 17 Detector 22a, 22b, 22c Motor driver

Claims (2)

[Claims] An overhead crane having a control device having a hanger and controlling travel and traverse based on a command signal from a host device and a moving speed command value calculated based on the command signal. In the traveling direction of the overhead crane, the position of the suspended load is managed and placed with respect to the traversing direction, and in the suspended load position detection device that detects the position of the suspended load by image processing, the traveling position of the overhead crane is detected. A traveling position detector for outputting a traveling position detection signal, a traversing position detector for detecting a traversing position of the overhead crane and outputting a traversing position detection signal, and detecting a height position of the hanging device. A height position detector for outputting a height position detection signal, a television camera provided downward on the hanging device and capable of capturing an image in an infrared region, and processing an image from the television camera. An image processing unit for detecting the position of the load, an infrared strobe provided on the hanging device and emitting light toward the suspended load, and provided on the hanging device or a rope suspending the device, A detector for detecting an inclination angle, the control device estimates and calculates the swing angle of the rope from the moving speed command value and the detection value of the detector, and the travel position detection signal and the The position of the suspended load obtained by the image processing unit is determined based on the traversing position detection signal, and further, a predetermined lifting operation is performed on the suspended load based on the estimation calculation result and the height position detection signal. A position detection device for a suspended load, wherein the position of a part is corrected and calculated. 2. The position detection apparatus for a suspended load according to claim 1, wherein timing of light emission of said infrared strobe and timing of image input to said image processing section are synchronized. apparatus.