KR100368363B1 - Device for measuring list of spreader - Google Patents

Abstract

PURPOSE: A list measuring apparatus for a spreader is provided to control the position of the spreader by detecting the list angle of the crane spreader accurately with sensing image of linear elements. CONSTITUTION: A list measuring system for a spreader is composed of an image detecting pattern(110) having plural linear elements arranged in parallel on the spreader; a camera(120) installed vertically in the upper part of the image detecting pattern to reduce or enlarge the image according to the distance from the image detecting pattern with a zoom unit; a distance measuring unit providing vertical distance information between the camera and the upper face of the spreader; a zoom controller(122) adjusting the zoom unit according to the vertical distance information from the distance measuring unit; and an angle output unit(170) calculating the list angle of the spreader corresponding to the gap between linear elements. The position of the spreader is controlled by measuring the list angle of the spreader accurately.

Description

Spreader List Measuring Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring a posture outside a spreader installed in a crane, and more particularly, to an apparatus for measuring a spreader list for measuring a list of spreaders.

In general, a container crane uses a spreader suspended from a rope to move a container to a required position.

1 is a view showing the configuration of a general crane. In FIG. 1 a crane 10 is shown. This crane 10 is provided with the trolley 12 pieces. This trolley 12 is transversely movable along the trolley traveling part 14. The cab 16 is provided on one side of the lower surface of the trolley 12. The spreader 18 is suspended by the rope 17 on the lower surface of the trolley 12 next to the cab 16. This spreader 18 is for clamping the container 20. Such a crane is provided with a hoist (not shown) for raising and lowering the spreader 18, which raises and lowers the spreader 18 by winding or unwinding the rope 17 on which the spreader 18 is suspended. A motor for driving such hoists is usually provided with a hoist encoder to provide height information of the spreader 18.

When the crane moves in such a crane and stops at the target position, loads such as spreaders and containers suspended on the rope are shaken, and it takes a long time to land the container at the correct position. In order to control the shake of such a spreader, the apparatus which measures the shake amount of a spreader etc. is essential. Examples of shakes of the spreader include skew, trim, and list.

2 is a diagram for explaining the shaking of the spreader or the like. As shown in FIG. 1, the shake around the x-axis is called a list, the shake around the y-axis is trimmed, and the shake around the z-axis is called skew.

Conventional spreader attitude measuring devices have been developed for measuring the skew, other sway, and the like described above, but no device for accurately measuring the list of spreaders has been developed.

It is an object of the present invention to provide an apparatus capable of accurately measuring a list of spreaders.

An object of the present invention as described above is provided in a crane having a spreader and a hoist for lifting and lowering the spreader as necessary, in the spreader list measuring apparatus for measuring the list of the spreader,

Reducing or enlarging an image recognition pattern having a plurality of straight lines displayed in parallel at a predetermined interval on the upper surface of the spreader, installed vertically above the image recognition pattern, according to the distance from the image recognition pattern A camera having a zoom means, a distance measuring means for providing vertical distance information between the camera and the upper surface of the spreader on which the image recognition pattern is displayed, and a zoom for adjusting the zoom means according to the vertical distance information provided by the distance measuring means. And an angle calculating means for calculating a list angle of the spreader according to the distance between the controller and the straight lines photographed by the camera.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

3 is a view showing the installation position of the camera and the image recognition pattern constituting the spreader list measuring apparatus according to the present invention. 3 shows the trolley running portion 14 of the crane. The trolley 12 is provided with the trolley 12. This trolley 12 is transversely movable along the trolley traveling part 14. The cab 16 is provided on one side of the lower surface of the trolley 12. The spreader 18 is suspended by the rope 17 on the lower surface of the trolley 12 next to the cab 16. This spreader 18 is for clamping the container 20.

The image recognition pattern 110 constituting the spreader list measuring device according to the present invention is displayed on the upper surface of the spreader 18 as shown in FIG. This image recognition pattern 110 is shown in detail in FIG. The camera 120 is installed on the lower surface of the trolley 12 vertically above the image recognition pattern 110. The camera 120 is for photographing the image recognition pattern 110, and should have a zoom function. The zoom function of the camera 120 depends on the vertical distance information between the spreader 18 and the camera 110 provided by a hoist encoder installed in a hoist (not shown) for raising and lowering the spreader 18. It is good to let it be done. In some cases, a separate distance measuring device may be used to obtain vertical distance information.

4 is a diagram showing a planar shape of the image recognition pattern, and FIG. 5 is a diagram showing a plane view of the spreader on which the fourth image recognition pattern is displayed. As shown in FIG. 4, the image recognition pattern 110 includes a plurality of straight lines 112 arranged in parallel at a predetermined interval. These straight lines 112 are surrounded by the rim line 114. The dotted line outside the border line 114 represents the image area of the camera. The image recognition pattern 110 is displayed on the upper surface of the spreader 18 as shown in FIG. Here, the linear elements 110 should be arranged in the longitudinal direction of the spreader 18 (the x-axis direction in FIG. 1).

When the spreader 18 is inclined when viewed from above the image recognition pattern 110, the distance between the straight lines 112 becomes narrow. The spacing between the straight lines 112 at this time is inversely proportional to the list angle. That is, the list of spreaders can be known at intervals between the straight lines 112 of the image recognition pattern 110.

6 is a block diagram showing the configuration of the spreader wrist measuring apparatus according to the present invention. As shown in FIG. 6, the spreader list measuring apparatus according to the present invention includes an image recognition pattern 110 displayed on an upper surface of the spreader and a camera 120 for photographing the image recognition pattern 110. FIG. A zoom controller 122 is connected to the camera 120, and a hoist encoder 130 is connected to the zoom controller 122. Here, the hoist encoder 130 is for outputting the height information of the spreader, that is, the vertical distance information between the camera 120 and the image recognition pattern 110 to the zoom controller 122, and the zoom controller 122 is a hoist encoder ( 1] 0) to adjust the zoom means outside the camera 120 according to the vertical distance information between the camera 120 and the image recognition pattern 110 provided in. The adjusting of the zoom of the camera 120 is to maintain the constant size of the image captured by the camera 120 regardless of the distance between the image recognition pattern 110 and the camera 120.

The camera 110 is connected to an area detection unit 140, and a synchronization signal separation unit 150 is installed between the camera 120 and the area detection unit 130. The synchronization signal separation unit 150 separates the composite synchronization signal into horizontal and vertical synchronization signals and serves to apply the area detection unit 140. The area detection unit 140 extracts only image signals of linear elements of the image recognition pattern 110 based on the separated horizontal and vertical synchronization signals.

The area detection unit 140 is connected to the signal processor 160, and the signal processor 160 is connected to the angle calculator 170. The signal processor 160 converts the repetition period of the image signal for the linear elements applied by the area detection unit 140 into a frequency and outputs the converted frequency. This will be described later with reference to FIG. 7. The angle calculator 170 calculates the angle according to the frequency applied by the signal processor 160.

That is, the camera 120 captures the image recognition pattern 110 displayed on the upper surface of the spreader, and the hoist encoder 130 simultaneously measures the vertical distance between the camera 120 and the image recognition pattern 110 displayed on the upper surface of the spreader. Information is applied to the zoom controller 122. The zoom controller 122 adjusts the zoom of the camera 120 according to the vertical distance information applied from the hoist encoder 130. Accordingly, the image recognition pattern 110 is always drawn to the camera 120 at a constant size ratio.

The video signal of the camera 20 is applied to the area detection unit 140. At the same time, the synchronization signal separation unit 150 separates the complex synchronization signal and applies it to the area detection unit 140. The area detection unit 140 separates only image signals of linear elements of the image recognition pattern 110 among the image signals applied from the camera 120 based on the horizontal and vertical synchronization signals, and outputs them to the signal processor 160. do. Then, the signal processor 160 converts the repetition period of the video signal for the linear element into a frequency and outputs the frequency to the angle calculator 170. Then, the angle calculator 170 calculates the angle according to the frequency input from the signal processor 160. In other words, the list angle of the spreader is calculated.

7 is a diagram showing the relationship between the image of the image recognition pattern photographed by the camera and the frequency output from the signal processor of FIG. 6, and is shown in FIG. 7 (a) and 7 (b), respectively, whether or not a list is generated. . 7 (a) shows a case where a list is not generated in the spreader, and FIG. 7 (b) shows a case where a list is generated. Comparing the seventh (a) and the seventh (b), it can be seen that the spacing between the straight (112) and the seventh (a) is wider than the spacing of the straight (112). . Correspondingly, the frequency output from the signal processor of FIG. 6 is also different. In FIG. 7, it can be seen that the frequency increases when a list occurs in the spreader. This frequency is proportional to the angle of the wrist.

As described above, when the spreader list measuring device according to the present invention as described with reference to FIGS. 3 to 7 can be accurately measured, the spread angle of the spreader can be used to control the attitude of the spreader.

1 is a view showing the configuration of a general crane,

2 is a view for explaining the shaking of the spreader, etc.,

3 is a view showing the installation position of the camera and the image recognition pattern constituting the spreader list measuring apparatus according to the present invention,

4 is a view showing a planar shape of the image recognition pattern,

FIG. 5 is a view showing a plan view of the spreader on which the image recognition pattern of FIG. 4 is displayed;

6 is a block diagram showing the configuration of the spreader list measuring device according to the present invention;

FIG. 7 is a diagram illustrating a relationship between an image of an image recognition pattern imaged by a camera and a frequency output from the signal processor of FIG. 6.

* Explanation of symbols for main parts of the drawings

12: trolley 18: spreader

20: container 110: image recognition pattern

112: straight cow 120: camera

122: zoom controller 130: hoist encoder

140: region protection unit 150: synchronization signal separation unit

160: signal processing unit 170: angle calculation unit

Claims (5)

In the crane having a spreader and a hoist for raising and lowering the spreader as needed, the spreader list measuring device for measuring the list of the spreader, An image recognition pattern having a plurality of straight lines displayed in parallel at a predetermined interval on an upper surface of the spreader; A camera installed vertically above the image recognition pattern, the camera having zoom means for reducing or enlarging an image taken according to a distance from the image recognition pattern; Distance measuring means for providing vertical distance information between said camera and said spreader upper surface on which said image recognition pattern is displayed; A zoom controller for adjusting the zoom means according to the vertical distance information provided from the distance measuring means; And And an angle calculating means for calculating a list angle of the spreader according to the distance between the straight lines photographed by the camera. The apparatus of claim 1, wherein the camera is installed on a lower surface of the trolley of the crane for lateral movement of the spreader. The spreader list measuring device according to claim 1, wherein said distance measuring means comprises a hoist encoder. The image detection pattern of claim 1, wherein the angle calculating unit comprises: an area detection unit which selects and outputs image signals of linear elements of the image recognition pattern among the image signals of the image photographed by the camera; And a signal processor for converting the repetition period of the image signal for the linear elements of the frequency into a frequency and an angle calculator for calculating the list angle of the spreader according to the frequency generated by the signal processor. Device. The spreader list according to claim 4, wherein the angle calculating means further comprises a synchronization signal separation unit for separating the composite synchronization signal output from the camera into a vertical synchronization signal and a horizontal synchronization signal and outputting the composite synchronization signal to the area detection unit. Measuring device.