JP2001010778A - Method of detecting swing of load in crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the restraint of a mechanical movable part by a friction element and a projector cable in a crane by fitting a corner cube mirror to a suspension tool, and catching the locus of the reflected light from the corner cube mirror with a light receiver camera arranged at a position opposite to a load side so as to detect the swing of load. SOLUTION: One or plural corner cube mirrors 9 are arranged in a side surface (a surface at a right angle against the top surface) of a crane hook 5. The light from a light source 10 is reflected by the corner cube mirrors 9, and locus of the reflected light from the corner cube mirrors 9 is sampled within a secondary field of view of a light receiver camera 11. A vertical distance between the camera 11 and the crane hook 5 is obtained for correction on the basis of the hoisted quantity of a load measured by a hoisting height measuring sensor 6, and secondary moving quantity of the reflected light from the corner cube mirrors 9 and the swing speed are measured so as to detect the swing of load in a crane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane load deflection detection method for detecting a load deflection of a crane using a corner cube mirror attached to a crane hook (hanging tool).

[0002]

2. Description of the Related Art Conventionally, as a method of detecting a run-out of a crane,
There are first to third prior arts described below.
A first prior art is disclosed in Japanese Patent Application Laid-Open No. 6-208624, in which a marker is provided on a hanging tool, and the marker captured by a camera on a crane trolley is recognized by image processing and tracked. .

A second prior art is disclosed in Japanese Patent Laid-Open No. 9-40365.
In the above publication, a weight that can rotate on a horizontal axis and a projector that can rotate integrally with the weight are provided on the hanging device, so that the light is directed to the light receiver on the crane side, and the trajectory is provided. Is a method that enables tracking.

A third prior art is disclosed in Japanese Unexamined Patent Publication No. Hei.
No. 6 discloses a method in which a light projector is provided on a hanging tool, collected by a condenser lens, and traced by a camera device.

[0005]

The prior art described above has the following problems. In other words, the first prior art has a disadvantage that the reflected light from the marker is diffused and attenuated over a wide range, and the signal S / N deteriorates. In particular, large noise such as the sun had a great influence. Further, in the first prior art, in order to recognize the shape such as the center of gravity of the mark, it is necessary to strictly control the installation accuracy of the mark in the camera direction.

[0006] The second prior art is not only affected by the frictional element of the turning mechanism of the light projector, but also deteriorates the convergence of light to the light receiver on the crane side due to the restriction of the power cable to the light projector. There were drawbacks. In the second prior art, it is necessary to provide a power source for the projector on the side of the hanging tool,
There is a drawback that the cost is high because movable wiring from the crane body to the hanging tool is required.

[0007] The third prior art has a drawback that it is necessary to provide a power source for the light projector on the hanging device side, and a movable wiring from the crane main body to the hanging device is required, resulting in an increase in cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to suppress the diffusion of reflected light, improve the signal-to-noise ratio, and to mount a corner cube mirror on a hanging device. It is not necessary to strictly control the installation accuracy for the camera orientation, furthermore, it is possible to focus the signal light without any special contrivance in the projection direction of the projector, there is no frictional element of the mechanical movable part, and the constraint by the projector cable There is no crane load deflection detection method.

[0009]

In order to achieve the above object, an invention according to a first aspect has a traveling body configured to be able to traverse, and is supported by the traveling body and a hanging member for suspending a load. A crane having a corner cube mirror attached to the hanging tool, and catching the trajectory of the reflected light from the corner cube mirror with a light-receiving camera disposed at a portion opposite to the load side, whereby the crane of the crane This is a crane load deflection detection method for detecting load deflection.

In order to achieve the above object, the invention corresponding to claim 2 detects and corrects a vertical distance between the light receiving camera and the hanging device to detect a swing of the crane. This is a method for detecting the run-out of the crane.

According to a third aspect of the present invention, a vertical distance between the light receiving camera and the hanging device and a horizontal distance of the traveling body are obtained and corrected.
The crane load deflection detection method according to claim 1, wherein the load deflection of the crane is detected.

According to a fourth aspect of the present invention, in order to achieve the above object, a distance from a predetermined position to the traveling body is obtained and corrected to detect a load fluctuation of the crane. Is the way.

According to a fifth aspect of the present invention, in order to realize the above object, the corner cube mirror is mounted on an upper surface of the hanging member. This is a crane load deflection detection method for detecting a load deflection of the crane.

According to a sixth aspect of the present invention, in order to achieve the above object, the corner cube mirror is attached to a side surface of the hanging member. This is a crane load deflection detection method for detecting a load deflection of the crane.

In order to achieve the above object, an invention according to claim 7 is that a plurality of corner cube mirrors are attached to the hanging tool, and an appropriate corner cube mirror is selected and used according to the position of the hanging tool. Claim 2, characterized in that
A crane load fluctuation detection method for detecting a load fluctuation of the crane according to any one of Items 3 and 4.

According to any one of the first to seventh aspects of the present invention, since the corner cube mirror is used, the diffusion of the reflected light is suppressed, the S / N of the signal is improved, and the hanging tool is used. There is no need to strictly control the mounting accuracy of the corner cube mirror to be installed in the camera direction, and signal light can be collected without any special contrivance in the light projection direction of the light projector. It is possible to provide a crane load deflection detection method that is not restricted by a cable.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is characterized in that a corner cube mirror is mounted on an upper surface of a hanging tool, etc., supported by a traveling body of a crane and a load is hung from the corner cube mirror within a two-dimensional field of view of a light receiving camera. This is a crane load deflection detection method for detecting a load deflection of a crane by capturing the trajectory of light. This will be described below with reference to the drawings.

<First Embodiment> As shown in FIG. 1, a crane main body 1 is movable in a predetermined direction, for example, the Y-axis direction, along an opposing beam, for example, disposed above an upper part of a building. A traveling body, for example, a crane club 2 is disposed on the crane main body 1 so as to be movable in the axial direction of the crane main body 1, for example, in the X-axis direction. Crane club 2
Supports a crane hook (hanging tool) 5 for suspending a load so as to be vertically movable by a rope 4 of a hoisting machine 3. The crane club 2 is provided with a hoist height measuring sensor 6 for measuring the hoist height. The crane main body 1 is provided with a traversing distance measuring sensor 7 for measuring the moving distance of the crane club 2 in the traversing direction.

One corner cube mirror 9 is mounted on the upper surface of the crane hook 5 in a substantially vertical direction, and
An optical path limiting plate (optical path shielding plate) 8 is disposed so as to block an optical path of a predetermined solid angle or more from a vertical perpendicular line. That is, the solid angle of light that can enter the corner cube mirror 9 can be adjusted by the optical path limiting plate 8.

A light source (emitter) 10 for irradiating light to the corner cube mirror 9 and a reflected light from the corner cube mirror 9 are provided on one surface of the crane club 2 at a position facing the corner cube mirror 9. A light receiving camera 11 for receiving light is provided. The corner cube mirror 9
No matter what angle the light beam is incident on the effective entrance surface,
This is a type of prism that can emit the reflected light from the surface of the corner cube mirror 9 in parallel with the incident light.
This means that, for example, within the limit of the acceptance angle, if a beam having a diameter that is the full diameter of the corner cube is made incident, the reflected beam completely overlaps with the incident light beam and returns. The corner cube mirror 9
Like the right-angle prism, the principle of total internal reflection is used.

The corner cube mirror 9 is not limited to one, but may be plural. In this case, the corner cube mirror 9 may be provided on the side surface (the surface perpendicular to the upper surface) of the crane hook 5. In such a configuration, the light from the light source 10 is irradiated to the corner cube mirror 9 via a half mirror (not shown), and the reflected light from the corner cube mirror 9 is reflected within the two-dimensional field of view of the light receiving camera 11. The trajectory of the reflected light from the corner cube mirror 9 is sampled, and the vertical distance between the camera 11 and the crane hook 5 is obtained and corrected from the amount of hoisting of the load measured by the hoisting height measuring sensor 6, and the corner is corrected. By measuring the two-dimensional movement amount and the deflection speed of the reflected light from the cube mirror 9, the load deflection of the crane can be detected.

FIG. 2 is a view for explaining the principle of the measurement. The corner cube mirror 9 is mounted on the upper surface of the crane hook 5 in a substantially vertical direction.
The light incident on the corner cube mirror 9 from is reflected only in the range of the diameter of the corner cube mirror 9 in the direction of the projection light source and is reflected. At this time, the projection light to the portion other than the corner cube mirror 9, for example, to the crane hook 5 itself is reflected by the reflection characteristics of the background object. Even if the reflected light becomes specular reflected light in the direction of the light source, the intensity is sufficiently weak. If the center of the received light intensity distribution received by the light receiving camera 11 is identified by image processing, the reflected light reflected by the corner cube mirror 9 Can be determined.

Here, since the light source 10 itself is a divergent light source, the reflected light reflected from the corner cube mirror 9 also becomes a divergent light source using the aperture of the corner cube mirror 9 as a simulated light source. As for the position,
By a conventionally known technology such as the half mirror 12,
The reflected light from the light source 10 can be extracted and guided to the light receiving camera 11.

<Modification of First Embodiment> In the embodiment of FIG. 1, the light source 10 and the light receiving camera 11 may be installed on the crane main body 1 other than the crane club 2, and in this case, the crane club 2 traverses. The directional distance is separately measured and corrected by the traversing distance measuring sensor 7, and the two-dimensional movement amount and the deflection speed of the reflected light of the corner cube mirror 9 on the crane hook 5 are measured. Load deflection can be detected.

According to the first embodiment described above, the following operational effects can be obtained.

(1) Since the corner cube mirror 9 attached to the crane hook 5 is used, the diffusion of the reflected light is smaller than the method of using the reflected light for the mark on the crane hook shown in the first prior art. S / S
N is improved. In particular, with respect to large noise such as the sun, by removing the position of the sun from the straight line connecting the light source 10 and the corner cube mirror 9 of the crane hook 5, the sun reflection noise from the corner cube mirror 9 is removed. it can.

(2) Compared to the system using reflected light on a mark on a hanging tool shown in the first prior art, a light source 10 is provided at a point on a crane located within a solid angle at which the corner cube mirror 9 can enter. And the light receiving element such as the light receiving camera 11 is sufficient, so that it is sufficient to install it within the solid angle of the 90-degree corner cube mirror 9, and it is necessary to strictly control the installation accuracy of the corner cube mirror 9 to be attached to the hanging tool with respect to the camera direction. There is no.

(3) Since the corner cube mirror 9 returns the reflected light accurately in the direction in which the light is received, the signal can be transmitted without any special contrivance in the light projection direction of the light projector as compared with the method in which the light projector is provided on the hanging tool. Light can be collected and there is no frictional element of the mechanical movable part, and there is no restriction by the projector cable.

(4) The crane body 1 such as a power cable to the light source 10 is different from the method in which the projector is provided on the hanging tool.
There is no need to install a movable cable from the cable to the hanging device, and the cost is low.

(5) In the conventional method, it is assumed that the wire is not loosened or stretched, and the tongue for grasping the hook and the load suspended therefrom is an integral rigid body because of, for example, the amount of lifting of the load. The three-dimensional shake was estimated from the shake measurement on the plane. In the present embodiment, it is only necessary to secure a limited field of view to the corner cube mirror 9 as compared with a marker or the like that required a perfect reflection shape in the past, so that it is possible to measure the swing at a position closer to the load itself.

Whether the two-dimensional position of the first corner cube mirror, the projector and the light receiving camera based on the field of view from above and the two-dimensional position of the second corner cube mirror, the projector and the light receiving camera based on the side view are used in combination, Alternatively, when used in combination with a laser range finder that is diffusely projected by a lens, the three-dimensional position of the portion where the corner cube mirror is attached can be directly measured.

If it is attached to, for example, a tongue which is located closer to the load than the hook and is held by the hook and grips the load, the influence of the extension and loosening of the wire and the displacement of the engagement portion where the hook and the tongue are not fixed, etc. The load swing can be measured closer to the load without receiving it.

<Second Embodiment> As shown in FIG. 3, a light source 10 is provided on the lower surface of the crane body 1 at one end thereof.
b and a light receiving camera 11b, and a load swing detection method for a crane in which a corner cube mirror 9b is provided on the side of the crane hook 5. In this case, the light source 1
Even when the light from 0b is at the lower limit of the unloading of the load, the light is incident only to the aperture of the corner cube mirror 9b, and the corner cube mirror 9b is mounted slightly upward so as not to enter by the optical path limiting plate 8. The light source 10b for projecting the light into the corner cube mirror 9b is attached to the crane main body 1 so that the light does not enter the corner cube mirror 9b by the optical path limiting plate 8.

The other structure is the same as that of FIG.

At one point on the crane main body 1 located within the solid angle at which the corner cube mirror 9b can be incident as set in this way, a light source 10b for the corner cube mirror 9b is provided.
A light receiving element such as a light receiving camera 11b for reflected light from the corner cube mirror 9b is installed via a half mirror or the like (not shown), and a locus of the reflected light from the corner cube mirror 9b within a two-dimensional field of view of the light receiving camera 11b. And the distance in the traverse direction between the light receiving camera 11b and the hook suspension center is obtained from the traversing position of the crane club 2 which is separately measured, and corrected to obtain the reflected light 2 of the corner cube mirror 9b on the side surface of the crane hook 5. By measuring the dimensional movement amount and the swing speed, it is possible to detect the swing of the load viewed from the side of the crane.

<Modification of Second Embodiment> In FIG. 3, a light source 10a and a light-receiving camera 11a, and a light source 10b and a light-receiving camera 11b are provided on the lower surface of the crane main body 1 and on both ends thereof. The corner cube mirrors 9a and 9b are respectively attached to the two opposing side surfaces of the crane hook 5, and as a result of the crane club 2 traversing,
When the light from the light source 10a on one side comes out of the range of the incident visual field of the corner cube mirror 9a on the side, the light source 10a on the side is turned off and the other opposing side can secure the incident visual range of the corner cube mirror 9b. Side light source 10
b is turned on, and the measurement camera 11b is configured to switch to the system of the other opposite side surface. By measuring the two-dimensional movement amount and shake speed of the reflected light of the corner cube mirrors 9a and 9b from the side , It is possible to detect the deflection of the crane Y'-Z 'plane.

<Third Embodiment> As shown in FIG. 4, on the upper surface of a crane hook 5 installed on the load side of the crane,
The corner cube mirror 9 is mounted almost vertically, and the beam diameter is set so as to cover the range of deflection of the corner cube mirror 9 at one point on the crane club 2 located within the solid angle at which the corner cube mirror 9 can enter. A laser range finder 13 that emits the diffused laser beam and measures the distance is installed, and a light source 10 for the corner cube mirror 9 is provided near the one point on the crane club 2 and near the installation position of the laser range finder 13. And a light receiving element such as a camera 11 for receiving light reflected from the corner cube mirror 9 and a laser distance meter 13.
It is processed at a different wavelength characteristic or at a different timing, and is installed via a half mirror or the like.

In such a configuration, the trajectory of the reflected light from the corner cube mirror 9 is sampled within the two-dimensional field of view of the light receiving camera 11, and the crane hook 5 and the crane The vertical deflection of the measurement point on the club 2 is obtained and corrected, and the three-dimensional movement amount and the deflection speed of the reflected light of the corner cube mirror 9 on the crane hook 5 are measured to detect the deflection of the crane load. it can.

Regarding the method of detecting the load swing of the crane,
This will be described with reference to FIG.

A laser distance meter 13 for emitting a laser beam diffused by a lens as shown in FIG. 5 is provided near the two-dimensional plane hook shake measuring light projecting / receiving system shown in FIG. Corner cube mirror 9 of light intensity
If the intensity of the reflected light from the light source is used as a signal, the corner cube mirror 9 on the crane hook 5 can be used.
The distance to can be measured.

If the distance between the installation position of the two-dimensional plane hook swing measurement light emitter / receiver in FIG. 4 and the installation position of the laser range finder 13 in FIG. 5 is sufficiently shorter than the distance from the laser range finder 13 to the crane hook 5. The distance measured by the laser range finder 13 to the crane hook 5 can be approximated to the distance from the two-dimensional hook swing measurement light emitter / receiver to the hook.

Therefore, the three-dimensional hook swing can be observed as viewed from the two-dimensional plane hook swing measuring light emitter / receiver.

Of course, the laser range finder 13 and the two-dimensional plane hook swing measurement light emitter / receiver are designed so that there is no mutual influence.
Consideration such as selecting a different wavelength or performing temporal filtering is a well-known technique.

<Fourth Embodiment> The following systems a and b are
It is assumed that switching is performed similarly to the second embodiment described above.

As shown in FIG. 6, a corner cube mirror 9 is provided on the side of the crane hook 5 installed on the load side of the crane.
a, 9b are mounted horizontally and slightly upward, and are arranged within the solid angle at which the corner cube mirrors 9a, 9b set in this way can enter. At one point on the crane body 1,
Laser distance meters 13a and 13b for measuring the distance by emitting a laser beam having a beam diameter diffused so as to cover the range of deflection of the corner cube mirrors 9a and 9b are provided. Near the laser range finder 13a. Near the installation position of 13b, light sources 10a, 10b to corner cube mirrors 9a, 9b and light receiving camera 11 for reflected light from corner cube mirrors 9a, 9b
The light receiving elements such as the laser distance meters 13a and 13b
b, processed at a different wavelength characteristic or at a different timing, and installed via a half mirror or the like.
In the two-dimensional field of view 11b, the corner cube mirrors 9a, 9
The trajectory of the reflected light from a is sampled, and the vertical distance between the crane hook 5 and the measuring point on the crane main body 1 is obtained and corrected from the measured distances of the laser distance meters 13a and 13b. By measuring the three-dimensional movement amount and the deflection speed of the reflected light from the upper corner cube mirrors 9a and 9b, the deflection of the crane can be detected.

The fourth embodiment is a case where the above method is similarly applied to a swing measurement system on the side surface of the crane hook 5.

Here, since the light sources 10a and 10b themselves are divergent light sources, the reflected light reflected from the corner cube mirrors 9a and 9b also becomes a divergent light source using the diameter of the corner cube mirrors 9a and 9b as a pseudo light source. Camera 11a,
Regarding the installation position of 11b, the light reflected on the light source can be extracted and guided to the light receiving cameras 11a and 11b by a conventionally known technique such as a half mirror.

Thus, the swing of the crane hook 5 in the two-dimensional plane viewed from the light sources 10a and 10b can be observed. Here, since the light source 10 from the crane hook 5 can be attached relatively directly above the crane hook 5,
If the light can be projected in the range of the maximum swing of the crane hook 5, a light projection field of an angle A or more in FIG. 7 is not required.

On the other hand, the entrance / reflection surfaces of the corner cube mirrors 9a and 9b on the side of the crane hook 5 shown in FIG.
We want to design the a and 10b so that they are closer to the top than to the side, so that they can be easily installed on a crane.

Therefore, as shown in FIG. 7, when the optical path shielding plate 14 is attached, the incident light from the side projector 15 does not need to be received and reflected by the upper corner cube mirror, thereby preventing disturbance of the side measuring system. There is an advantage in the crane installation design of the side measurement system equipment.

<Modifications> The present invention is not limited to the above-described embodiments, but can be modified as follows.

(1) In the above-described embodiment, the corner cube mirror attached to the crane hook falls within the effective field of view of the two-dimensional plane hook swing measurement light emitter / receiver and the laser rangefinder (particularly, the upper part of the hook). Etc.). However, when applying the crane hook, the range of movement of the crane hook is large, and the corner cube mirror attached to the crane hook is out of the effective field of view of the two-dimensional plane hook swing measurement emitter / receiver and laser rangefinder. Need to be considered.

That is, the traversing position of the crane club, the hoisting position of the hook, and the like are measured by the existing techniques such as the PLG and the laser distance meter, and the hook position in the space when the hook is stationary is calculated in advance. If the position of the upper corner cube mirror deviates from the effective field of view of the two-dimensional plane hook swing measurement light emitter / receiver and the laser distance meter, the following is performed. In other words, switch to a measuring instrument set to another field of view, or install the two-dimensional plane hook swing measurement light emitter / receiver and the laser rangefinder on a head that can move freely, etc. Performing a design, such as entering, is a matter to be determined according to the working conditions to be applied.

(2) Although it has been described herein that the intensity distribution profile of the reflected light is received by the camera and the center thereof is identified as shown in FIG. 2, for example, four light receiving elements may be used at right angles even if the light receiving element is not a camera. , A plurality of optical power meters are arranged equidistantly around the center position of the reflected light when the hook is stationary, and the power distribution from the intensity distribution profile of the projector previously known from the received light amount of each power meter. Calculated from the average of the reflected light profile 2
An approach that identifies the center position so that the squared error is reduced is also possible.

[0055]

According to the present invention described above, the diffusion of the reflected light is suppressed, the signal-to-noise ratio is improved, and the installation accuracy of the corner cube mirror to be mounted on the hanging fixture with respect to the camera needs to be strictly controlled. It is possible to provide a crane load deflection detection method that can collect signal light without any special contrivance in the light projection direction of the light projector, has no frictional element of the mechanical movable part, and is not restricted by the light projector cable. it can.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a first embodiment of a crane load deflection detection method according to the present invention.

FIG. 2 is a conceptual diagram for explaining a method of observing hook swing by optical processing of a corner cube mirror in FIG. 1;

FIG. 3 is a view for explaining a crane load deflection detection method according to a second embodiment of the present invention.

FIG. 4 is a view for explaining a crane load deflection detection method according to a third embodiment of the present invention.

FIG. 5 is a view for explaining the laser range finder of FIG. 4;

FIG. 6 is a view for explaining a crane load deflection detection method according to a fourth embodiment of the present invention.

FIG. 7 is a view for explaining the effect of the light-projecting shielding plate on the corner cube mirror of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Crane main body 2 ... Crane club 3 ... Hoisting machine 4 ... Rope 5 ... Crane hook (hanging tool) 6 ... Hoisting height measuring sensor 7 ... Traversing distance measuring sensor 8 ... Optical path limiting plate 9, 9a, 9b ... Corner Cube mirror 10, 10a, 10b ... Light source 11, 11a, 11b ... Receiving camera 12 ... Half mirror 13, 13a, 13b ... Laser distance meter 14 ... Optical path shield plate 15 ... Side projector

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasutoshi Fujikawa 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Haruo Odaka 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan (72) Inventor Toyohiro Yaemoto 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan F-term (reference) 3F204 AA02 BA02 CA01 CA03 DB06 DB08 DC07 EA11 EB04 EB08

Claims (7)

[Claims] 1. A crane having a traveling body configured to be able to traverse, supported by the traveling body, and having a hanger for hanging a load, wherein a corner cube mirror is attached to the hanger, A load deflection detection method for detecting the load deflection of the crane by capturing the trajectory of the reflected light from the light source with a light receiving camera disposed at a portion opposite to the load side. 2. The crane load deflection detection method according to claim 1, wherein a vertical distance between the light receiving camera and the hanging tool is obtained and corrected to detect a load deflection of the crane. 3. The crane load deflection detection method according to claim 1, wherein a vertical deflection distance between the light-receiving camera and the hanging device and a traverse distance of the traveling body are obtained and corrected to detect a load deflection of the crane. . 4. The crane load fluctuation detecting method according to claim 1, wherein a distance from a predetermined position to the traveling body is obtained and corrected to detect a load fluctuation of the crane. 5. The crane load deflection detecting method according to claim 2, wherein the corner cube mirror is mounted on an upper surface of the hanging tool. 6. The crane load deflection detecting method according to claim 2, wherein the corner cube mirror is attached to a side surface of the hanging tool. 7. The hanging cube according to claim 2, wherein a plurality of corner cube mirrors are attached to the hanging tool, and an appropriate corner cube mirror is selected and used according to the position of the hanging tool. 2. A crane load runout detecting method for detecting a runout of a crane described in (1).