JP2907325B2 - Deflection angle detection apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing angle detecting apparatus and method for detecting a swing angle of a moving object such as a suspended load suspended by various cranes such as a container crane.

[0002]

2. Description of the Related Art One prior art regarding deflection angle detection is as follows.
For example, it is disclosed in JP-A-6-219681. FIG. 10 shows a schematic configuration of a prior art disclosed in Japanese Patent Application Laid-Open No. 6-219681. 10A shows the entire configuration, and FIG. 10B shows the configuration of the target.
A target 4 is mounted on a hanging tool 3 suspended from a trolley 1 of a container crane via a wire 2. The field of view of a video camera 5 installed below the trolley 1 is aimed at the target 4. A band-shaped marker 6 is provided at the center of the target 4, and an image thereof is taken by the camera 5. The moving state of the hanging tool 3 is detected by image processing of the captured image, and the swing angle is calculated.

[0003] When a container crane or the like is used to load and unload a container with the hanging tool 3, it is necessary to quickly suppress the swing of the hanging tool 3 suspended by the wire 2. Since the container can be handled by the hanging tool 3 after the run-out is suppressed, if it takes time to reduce the run-out, the container cannot be handled quickly. In order to suppress the deflection of the wire 2, the current deflection angle is detected, and feedback control is performed to reduce the deflection angle.

[0004]

SUMMARY OF THE INVENTION Japanese Patent Laid-Open No. Hei 6-21968
In the prior art, although the deflection angle and the skew angle of the attitude angle of the wire 2 can be measured by image processing, the roll angle and the pitch angle of the attitude angle cannot be measured. In a container crane, the lifting device 3
The length of the wire 2 changes from the top to the ground by about 40 m, the size of the image of the band-like marker 6 to be captured by the camera 5, which is an optical sensor for imaging, greatly changes, and the entire detection range It is difficult to accurately detect the shake angle and the posture angle over a wide range.

Further, since container cranes and the like are assumed to be used outdoors, current imaging sensors are susceptible to optical disturbances such as sunlight and fog at the time of detection, and are stable to prevent vibration. And the deflection angle cannot be detected. Further, since the target 4 is used outdoors, it is easily affected by ultraviolet rays, temperature, and the like.

SUMMARY OF THE INVENTION It is an object of the present invention to measure the attitude angle together with the deflection angle, to be able to measure with high accuracy even if the length of the wire changes, and to be stably used without being affected by disturbance even when used outdoors. An object of the present invention is to provide a shake angle detecting device and method capable of measuring.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an apparatus for detecting a swing angle of a suspended moving object, comprising: a first target arranged at one end of an upper surface of the moving object and having a substantially square shape. A second target, which is disposed at the other end of the upper surface of the moving body and is substantially square, a first imaging unit that images the first target from above, and an image of the second target from above The center of gravity of each target is calculated by the second imaging unit and image processing based on the composite image information of the first and second targets imaged by the first and second imaging units, and the temporal position of each centroid position is calculated. An image processing means for detecting a shake angle based on a change. According to the present invention, the first and second targets, each having a substantially square shape, are arranged at both ends of the upper surface of the suspended movable body, and the center of gravity is obtained from the composite image information obtained by imaging each target by the upper two imaging means. The position can be calculated, and the deflection angle can be detected from the temporal change of the position of the center of gravity.

In the present invention, the image processing means detects a skew angle among posture angles of the moving body together with the shake angle. According to the present invention, since the distance between the positions of the centers of gravity can be measured with a sufficient length, the skew angle, which is one of the posture angles, as well as the deflection angle can be detected with high accuracy.

According to the present invention, there is provided a third target disposed on the upper surface of a moving body such that the positions of the centers of gravity are spaced from a straight line connecting the positions of the centers of gravity of the first and second targets. The processing means detects a skew angle, a roll angle, and a pitch angle as posture angles of the moving body together with the shake angle. According to the present invention, the first
When a third target is provided in addition to the second target and the barycentric position of each target is calculated based on the captured image information, the barycentric position of the third target becomes the barycentric position of the first and second targets. Since the positions are separated from the connecting straight line, the swing angle, the skew angle, the roll angle, and the attitude angle of the pitch angle can be detected with high accuracy from the temporal change of the center of gravity of the three targets.

In the present invention, each of the targets can be changed in size as an image picked up by an image pickup means. According to the present invention, since the size of each target as an image to be imaged can be changed, the size is changed according to the length of the imaging distance from the imaging means, and is changed to a size suitable for the imaging distance to achieve high precision. Can be detected.

In the present invention, each of the targets is formed by arranging a plurality of semiconductor light emitting elements in a matrix, and is capable of changing a lighting state. According to the present invention, the target is formed by arranging a plurality of semiconductor light emitting elements in a matrix and the lighting state can be changed. Therefore, if the number of lighting semiconductor light emitting elements is increased, the area of the image of the target is increased. Is increased and the number is reduced, the area can be reduced.

Further, in the present invention, the semiconductor light emitting element has a synthetic resin lens, and an ultraviolet cut filter is mounted on a front surface of the synthetic resin lens. According to the present invention, since the semiconductor light emitting element has the synthetic resin lens, the emitted light can be efficiently imaged by the imaging means. Since the ultraviolet cut filter is mounted on the front surface of the synthetic resin lens, sunburn due to ultraviolet rays can be prevented.

In the present invention, the semiconductor light emitting device emits invisible light. According to the present invention, since the semiconductor light emitting element emits invisible light such as infrared light,
When the deflection angle is detected in a state where an operator is present nearby, a situation that distracts the operator can be avoided.

In the present invention, each of the targets is provided with a heat radiating means for cooling the semiconductor light emitting device. According to the present invention, since each target is provided with a heat radiating means for cooling the semiconductor light emitting element, even if the semiconductor light emitting elements are densely arranged, it is possible to prevent an excessive temperature rise and to stably swing the swing angle. Detection can continue.

In the present invention, a buffer is filled between the semiconductor light emitting elements of the respective targets.
According to the present invention, since a buffer is filled between the semiconductor light emitting elements, even if an impact is applied to the moving body, the transmission of the impact is suppressed, and the earthquake resistance can be improved.

Further, in the present invention, each of the imaging means is capable of switching the focal length of the optical system between long and short. According to the present invention, since each imaging unit can switch the focal length of the optical system between long and short, the focal length is switched according to the distance to the target, and an imaging state suitable for image processing is selected. The deflection angle can be detected with high accuracy.

Further, the present invention relates to a method for detecting a swing angle of a suspended moving body, wherein a plurality of targets are arranged at intervals on an upper surface of the moving body, and each target is connected to a plurality of semiconductor light emitting elements. They are arranged in a matrix and formed.
A swing angle characterized by performing image processing based on image information obtained by individually imaging each target from above and synthesizing the same, calculating a center of gravity of each target, and detecting a swing angle from a time change of each center of gravity position. It is a detection method. According to the present invention, a plurality of targets are arranged at intervals on the upper surface of the moving body, and each target formed by arranging a plurality of semiconductor light emitting elements in a matrix is individually imaged from above and synthesized. Image processing is performed based on the image information, and the center of gravity of each target is calculated. Since the shake angle is calculated from the time change of each position of the center of gravity, even if the imaging distance varies outdoors, the shake angle can be accurately detected.

Further, the present invention is characterized in that an attitude angle is calculated from a temporal change of each position of the center of gravity. According to the present invention,
Since the position of the center of gravity of multiple targets is detected and the attitude angle together with the deflection angle is detected, the positions of multiple points distributed on the upper surface of the moving object are accurately calculated, and the angle is reliably and accurately detected from the temporal change. can do.

Further, the present invention is characterized in that the size of the target is changed according to the imaging distance. According to the present invention, the size of the target is changed in accordance with the imaging distance, so that the larger the imaging distance is, the smaller the imaging distance is, the smaller the target size is.
A target having an appropriate size can be used for detecting the position of the center of gravity, and the detection accuracy can be improved.

Further, the present invention is characterized in that at the time of imaging a target, the focal length of the imaging optical system is switched according to the imaging distance. According to the present invention, when imaging a target,
Since the focal length of the image pickup optical system is switched according to the image pickup distance, the focal length of the image pickup optical system can be switched and an image can be taken in an optimal state even if the length of the hanging tool and the moving body suspended varies.

[0021]

FIG. 1 shows a configuration for detecting a deflection angle according to an embodiment of the present invention. 1A shows the entirety, FIG. 1B shows the upper surface of the hanger 13, and FIG. 1C shows the coordinate axis direction. At the lower end of a rope 12 hung from a trolley 11 of a container crane, a hanger 13 as a moving body is provided, and the container can be hung and transported. First and second targets 14a and 14b are respectively disposed on the upper surface of the hanger 13 on the left and right sides, and a plurality of cameras 1 mounted below the trolley 11 as imaging means.
Images are taken by 5a to 15d. In this embodiment, four cameras 15a to 15d are used, and each target 14a,
14b is imaged by two cameras. The first target 14a is imaged by the left wide-angle camera 15a when the imaging distance is short, and is imaged by the left telephoto camera 15b when the imaging distance is long. The second target 14b captures an image with the right wide-angle camera 15c when the image capturing distance is short, and captures an image with the right telephoto camera 15d when the image capturing distance is long. The center of gravity 16a, 16b of each target 14a, 14b is calculated by the image processing. Instead of switching cameras, the focal length can be changed using a zoom lens.

FIG. 2 shows an electrical configuration for detecting the skew of the swing angle and the attitude angle of the hanging member 13 using the cameras 15a to 15d of FIG. The target position detection circuit 20 switches between the four cameras 15 a to 15 d using the camera switch 21. The video signal from the camera selected by the camera switch 21 is transmitted to the video synthesizer 22.
Thus, the left camera image and the right camera image are combined, and the left and right combined images are provided to the image processing circuit 23. The image processing circuit 23 calculates the position of the center of gravity of each of the targets 14 a and 14 b and supplies the calculated position to the target position detection circuit 20. The target position detection circuit 20 also receives a signal indicating the length of the rope 12 extended, and detects a deflection angle and a skew on the basis of a temporal change in the position of the center of gravity of the targets 14a and 14b according to a principle described later. The target position detection circuit 20 switches the size of the left and right targets 14a and 14b via the target size switching and lighting circuit 24 based on the signal indicating the rope length.

FIG. 3 shows the configuration of each of the targets 14a and 14b. 3A is a plan view, and FIG. 3B is a cross-sectional view taken along line III-III of FIG.
Each of the targets 14a and 14b includes a light emitting diode (hereinafter abbreviated as “LED”) 3 that is a plurality of semiconductor light emitting elements.
0 is arranged in a matrix. Each LED3
0 is lit in pulse mode. Each LED 30 is molded in an optically transparent resin, and a synthetic resin lens 31 is formed in front of the LED 30. An ultraviolet cut filter 32 made of a transparent acrylic plate is mounted on a front surface formed by the synthetic resin lens 31. The ultraviolet cut filter 32 allows the synthetic resin lens 3
1 prevents deterioration due to ultraviolet rays and sunburn. The gaps formed between the LEDs 30 are filled with a buffer 33 such as silicon elastomer to protect against external impacts and improve the earthquake resistance. LE
A heat radiating plate 34 is provided around D30, and dissipates heat due to power loss when the LED 30 is turned on to cool. By cooling the LEDs 30, even if the LEDs 30 are densely arranged, an excessive rise in temperature can be prevented, and the life can be extended. The heat sink 34 is fixed to the circuit board 36 via the spacer 35. Each LED 30 is electrically connected to the circuit board 36, and a lead wire 37 to the outside is provided.
Is pulled out. The circuit board 36 is housed in a case 38, and the UV cut filter 32 is mounted on the sealing material 3.
9 to prevent intrusion of moisture and the like.

The LEDs 30 are arranged in a matrix of 18 × 18, and 320 LEDs with four corners missing are arranged.
It is also possible to switch on and turn on only the area 35 of 8. By changing the lighting state, it is possible to change the size of the captured image, prevent the image from protruding from the imaging screen at a short distance, secure a sufficient size at a long distance, and improve the accuracy of calculating the center of gravity. If the LED 30 emits invisible light, such as infrared light, it does not distract the worker's attention and is less susceptible to fog or the like.

FIG. 4 shows a configuration for detecting a swing angle and a posture angle according to another embodiment of the present invention. 4A illustrates the entirety, FIG. 4B illustrates the upper surface of the hanging device 13, and FIG. 4C illustrates the coordinate system 8, respectively. In the present embodiment, portions corresponding to the embodiment of FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted. In the present embodiment, the center of gravity 16c of the third target 14c is different from the first and second targets 14a and 14b.
Are arranged on the upper surface of the suspending device 13 so as to be spaced from a straight line connecting the centers of gravity 16a and 16b of the hanging device. Not only are they spaced apart in a plane, but the distance from the camera 15a is also varied by the spacer 40. One camera 15a simultaneously captures images of three targets 14a to 14c. According to the present embodiment, it is possible to detect the deflection angle of the hanging member 13 and all the posture angles of the roll angle, the pitch angle, and the skew angle. The electrical configuration for detecting these angles is basically the same as the configuration in FIG.

FIG. 5 shows the definition of the shake angle θh to be detected. As shown in FIG. 5A, the swing angle θh is an angle formed between the rope 12 and the vertical line when the rope 12 swings the most. As shown in FIG. 5B, the vertical direction is set so as to form a right-handed system with the z axis, the deflection direction as the x axis, and the y axis with the x and z axes.

FIG. 6 shows the definition of the skew angle θs. In contrast to the state shown in FIG.
Is the skew angle θs between the x-axis direction and the swing direction of the suspender 13 when the angular displacement is performed as shown in FIG. FIG. 6 (c)
Indicates the direction of the coordinate axis. The skew angle θs is an angle around the z-axis.

FIG. 7 shows the definition of the roll angle θr. FIG.
As shown in (a), the roll angle θr indicates the inclination of the hanger 13 as the angle θr formed between the normal of the upper surface and the z-axis when the hanger 13 swings by the swing angle θh. Considering the coordinate axes in FIG. 7B, the roll angle θr is an angle around the y-axis.

FIG. 8 shows the principle of calculating the roll angle θr by calculating the positions of the centers of gravity 16a and 16c of the targets 14a and 14c. The distance between a straight line connecting the centers of gravity 16a and 16b of the targets 14a and 14b and the center of gravity 16c of the target 14c is h, the height of the spacer 40 is L, the distance between the centers of gravity 16a and 16c is m, and the center of gravity 16 when tilted.
Let the horizontal distance between a and 16c be Δh. First, θ is obtained from the first equation.

[0030]

(Equation 1)

Next, θ 'is calculated from the following second equation.

[0032]

(Equation 2)

Further, θr is calculated from the following third equation as the difference between θ ′ and θ.

Θr = θ′−θ (3) Note that the twist angle θh, the skew angle θs, and the pitch angle θp are also:
It can be calculated according to the principle of operation based on a similar geometric relationship.

In the above embodiment, the targets 14a to 14a
As 14c, the LEDs 30 are arranged in a matrix and the size is changed by switching the lighting state, but such a configuration as a fan or a configuration like a diaphragm of a camera, etc.
A configuration in which the apparent area can be mechanically changed may be employed.

FIG. 9 shows the definition of the pitch angle θp. FIG.
As shown in FIG. 9B, when the hanger 13 is inclined with respect to the reference state as shown in FIG. 9A, the angle θp between the normal to the upper surface of the hanger 13 and the z-axis becomes the pitch angle. . As shown in FIG. 9C, the pitch angle θp is an angle around the x-axis.

[0037]

As described above, according to the present invention, the center of gravity of the first and second targets is calculated by image processing, and the swing angle is detected based on the temporal change of each center of gravity. However, it is hardly affected by disturbance, and the shake angle can be accurately detected even if the imaging distance changes.

Further, according to the present invention, since the positions of the centers of gravity of the first and second targets are calculated, the shake angle can be detected from the linear movement component as an image, and the movement direction based on the shake angle can be detected. The skew angle, which is one of the attitude angles, can be accurately detected from the angle difference between the skew angle and the reference direction.

Further, according to the present invention, since the third target is arranged on the upper surface of the moving body at an interval from a straight line connecting the positions of the centers of gravity of the first and second targets, image processing is performed. Three positions of the center of gravity can be calculated on the upper surface of the body, and the swing angle and the posture angle can be detected from the time change of the three positions of the center of gravity.

Further, according to the present invention, since the size of the image of the target to be picked up can be changed, it is possible to switch the size according to the distance to be picked up and to perform optimal image processing.

Further, according to the present invention, since the plurality of semiconductor light emitting elements form the target and the lighting state thereof can be changed, the lighting state can be switched to easily switch the size of the target.

Further, according to the present invention, the semiconductor light emitting element has a lens made of synthetic resin, and discoloration is prevented by an ultraviolet cut filter. Therefore, even if the semiconductor light emitting element is used outdoors under direct sunlight, the lens made of synthetic resin is deteriorated. Thus, stable detection of the deflection angle can be continued.

According to the present invention, since the target is formed by the semiconductor light emitting device that emits invisible light,
Even when the lighting state is changed, the worker is not deprived of his / her attention and can perform a stable operation.

Further, according to the present invention, since the target is provided with the heat radiating means for cooling the semiconductor light emitting element, the life of the semiconductor light emitting element can be prolonged and the stable operation can be continued.

Further, according to the present invention, a buffer is filled between the semiconductor light emitting elements, so that the semiconductor light emitting elements can be protected from the impact even if an impact is applied to the moving body, and the earthquake resistance can be improved.

According to the present invention, the optical system of the imaging means can switch the focal length in accordance with the imaging distance between the imaging means and the target. The deflection angle can be accurately detected.

Further, according to the present invention, since the torsion angle is detected from the temporal change of the position of the center of gravity of a plurality of targets, it is hardly affected by external disturbances, and highly accurate detection can be performed.

Further, according to the present invention, the attitude angle can be accurately detected.

According to the present invention, the position of the center of gravity can be calculated from an image having an appropriate size.

According to the present invention, at an appropriate focal length,
Imaging can be performed.

[Brief description of the drawings]

FIG. 1 includes a front view, a plan view, and a coordinate axis direction showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration for detecting a target 1 in the embodiment of FIG.

FIG. 3 shows targets 14a, 1 used in the embodiment of FIG.
It is the simplified top view and sectional drawing which show the structure of 4b.

FIG. 4 is a front view, a plan view, and a diagram showing a coordinate axis direction showing a simplified configuration of another embodiment of the present invention.

FIG. 5 is a simplified side view showing the definition of the deflection angle and a diagram showing the coordinate axis directions.

6A and 6B are a plan view showing a definition of a skew angle and a diagram showing a definition of a coordinate axis direction.

7A and 7B are a side view showing a definition of a roll angle and a view showing a coordinate axis direction.

FIG. 8 is a schematic diagram illustrating a principle of calculating a roll angle.

FIG. 9 is a simplified front view showing the definition of the pitch angle and a diagram showing the coordinate axis directions.

FIGS. 10A and 10B are a front view and a plan view showing a configuration of the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Trolley 12 Rope 13 Hanger 14a, 14b, 14c Target 15a-15d Camera 16a, 16b, 16c Center of gravity 20 Target position detection circuit 21 Camera switcher 22 Video synthesizer 23 Image processing circuit 24 Target size switching circuit and lighting circuit 30 LED DESCRIPTION OF SYMBOLS 31 Synthetic resin lens 32 UV cut filter 33 Buffer 34 Heat sink

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeru Sasaki 8 Harima-machi, Harima-cho, Kako-gun, Hyogo Kawasaki Heavy Industries, Ltd. Harima Plant (56) References JP-A-8-12260 (JP, A) JP-A Heisei JP-A-7-9370 (JP, A) JP-A-7-19862 (JP, A) JP-A-4-137402 (JP, A) JP-A-6-262982 (JP, A) JP-A-7-211454 (JP, A) A) Jikoh 3-116510 (JP, Y2) (58) Field surveyed (Int. Cl. ⁶ , DB name) G01C 15/00-15/14 B66C 13/08 G01B 11/26 G01C 3/06

Claims (14)

(57) [Claims] An apparatus for detecting a swing angle of a suspended moving body, comprising: a first target which is disposed at one end of an upper surface of the moving body and is substantially square; A second target arranged at an end and having a substantially square shape, a first imaging unit for imaging the first target from above, a second imaging unit for imaging the second target from above, The center of gravity of each target is calculated by image processing based on combined image information of the first and second targets imaged by the first and second imaging means, and the shake angle is detected based on a temporal change in the position of each center of gravity. A shake angle detection device, comprising: 2. The shake angle detecting device according to claim 1, wherein said image processing means detects a skew angle among posture angles of a moving body together with said shake angle. 3. The image processing means further comprising: a third target disposed on an upper surface of a moving body such that the positions of the centers of gravity are spaced from a straight line connecting the positions of the centers of gravity of the first and second targets. The shake angle detection device according to claim 1, wherein the detection unit detects a skew angle, a roll angle, and a pitch angle as posture angles of the moving body together with the shake angle. 4. The shake angle detecting device according to claim 1, wherein each of the targets can change a size of an image picked up by an image pickup means. 5. The deflection angle detection device according to claim 4, wherein each of the targets is formed by arranging a plurality of semiconductor light emitting elements in a matrix, and is capable of changing a lighting state. 6. The deflection angle detecting device according to claim 5, wherein the semiconductor light emitting element has a synthetic resin lens, and an ultraviolet cut filter is mounted on a front surface of the synthetic resin lens. 7. The deflection angle detecting device according to claim 5, wherein the semiconductor light emitting element emits invisible light. 8. The deflection angle detecting device according to claim 5, wherein each of the targets includes a heat radiating unit for cooling the semiconductor light emitting device. 9. The semiconductor device according to claim 5, wherein a buffer is filled between the semiconductor light emitting elements of the respective targets.
The deflection angle detection device according to any one of the above. 10. The apparatus according to claim 1, wherein each of the imaging units is capable of switching a focal length of an optical system between a long and short distance.
The deflection angle detection device according to any one of the above. 11. A method for detecting a swing angle of a suspended moving object, comprising: arranging a plurality of targets at intervals on an upper surface of the moving object; Arranged and formed, perform image processing based on image information obtained by individually capturing and synthesizing each target from above, calculate the center of gravity of each target, and detect the deflection angle from the time change of the position of each center of gravity A deflection angle detection method. 12. The shake angle detection method according to claim 11, wherein the posture angle is calculated from a temporal change of each position of the center of gravity. 13. The shake angle detection method according to claim 11, wherein the size of the target is changed according to the imaging distance. 14. The method according to claim 11, wherein a focal length of the imaging optical system is switched according to an imaging distance when imaging the target.