WO2011102165A1

WO2011102165A1 - Crane sway sensor and crane

Info

Publication number: WO2011102165A1
Application number: PCT/JP2011/050635
Authority: WO
Inventors: 陽一郎津村; 顕夫池田; 雅人小林; 伸郎吉岡
Original assignee: 三菱重工業株式会社
Priority date: 2010-02-19
Filing date: 2011-01-17
Publication date: 2011-08-25
Also published as: JP2013107709A

Abstract

A crane sway sensor capable of accurately detecting sway using a simple configuration. A crane sway sensor is provided with: an image-capturing section (10) which is provided to the crane body (C) and is oriented below the crane body (C); and a target section (20) which is provided to a lifting device (W) suspended from the crane body (C) and facing the image-capturing section (10) and which has an LED array element for emitting illumination light upward and having a light emitting surface formed by LED chips arranged in an array. If the minimum distance from the center of gravity of the light-emitting surface of the target section (20) to the edge thereof is d, the maximum stroke between the image-capturing section (10) and the target section (20) is L_MAX, and the instantaneous angle of field of view of the image-capturing element of the image-capturing section (10) is Q, the crane sway sensor satisfies the following relationship: Q × L_MAX < d

Description

Crane run-out sensor and crane

The present invention relates to a crane runout sensor and a crane.
This application claims priority based on Japanese Patent Application No. 2010-034785 filed in Japan on February 19, 2010, the contents of which are incorporated herein by reference.

As is well known, in various types of cranes such as container cranes, there are some which detect the swing angle and the swing amount of the suspension suspended from the crane body and control the swing of the suspension based on the detected value.

For example, in an apparatus for detecting a swing angle of a hanging tool described in Patent Document 1 below, a first target and a second target that are each formed in a substantially square shape and emit irradiation light upwards The first target and the second target are respectively imaged from above and arranged on one end and the other end of the upper surface of the image, and an image based on the composite image information of the imaged first target and second target Through the processing, the gravity center position of each target is calculated, and the deflection angle is detected based on the temporal change of the gravity center position.

Japanese Patent No. 2907325

However, in the prior art, since a plurality of light emitting elements are assembled on the first target and the second target, it is necessary to control the plurality of light emitting elements, and a drive circuit for the light emitting elements is provided. There was a problem of becoming complicated.

In addition, when the light emitting area of the light emitting element is inappropriate, the optical axis of the irradiation light emitted from the first target and the second target is blocked when the weather is rainy or foggy, and the position of the center of gravity Cannot be calculated, and there is a problem that erroneous detection occurs.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a crane runout sensor and a crane that can accurately detect runout with a simple configuration.

In order to achieve the above object, the present invention employs the following means.
That is, the crane shake sensor according to the present invention includes an imaging unit installed downward on the crane body and a plurality of LED chips arranged in an array, provided on a hanging tool suspended from the crane body. And a target portion having an LED array element that emits irradiation light upward from the light emitting surface formed by the plurality of LED chips, and d is the shortest distance from the center of gravity of the light emitting surface of the target portion to the edge. When the maximum stroke between the imaging unit and the target unit is L _MAX and the instantaneous viewing angle of the imaging device of the imaging unit is Q, the following relationship is satisfied.
Q x L _MAX <d
According to this configuration, since the target unit including the LED array element in which the light emitting surface is formed by the plurality of LED chips arranged in an array is provided, the light source of the target unit is configured by a single element. Thereby, since the structure of the drive circuit which controls a target part can be simplified, the structure of the crane runout sensor whole can be simplified.
In addition, according to the above configuration, since the sufficient light emitting area of the target unit is ensured by satisfying the relationship of the above formula, even if the weather is rain or fog, any irradiation light from the target unit Will reach each image sensor of the imaging unit, and erroneous detection of the target unit can be suppressed.

In addition, the target unit includes a lens that collects and equalizes the irradiation light emitted from the LED array element.
According to this configuration, since the lens that collects and equalizes the irradiation light emitted from the target unit is provided, the irradiation light can reach the imaging element without being diffused.

Further, when the maximum shake amount in each stroke of the lifting tool in the horizontal direction is X and the projection angle of the lens is P (β in the embodiment), the following relationship is satisfied.
X / L <P / 2
According to this configuration, since the relationship of the above equation is satisfied, for example, even if the hanging tool is displaced due to shaking, the target unit does not deviate from the imaging range of the imaging unit. As a result, it is possible to suppress erroneous detection that occurs when the target unit is out of the imaging range of the imaging unit.

In addition, the wavelength of the irradiation light of the LED array element is longer than the peak wavelength of the sunlight spectrum.
According to this configuration, since the wavelength of the irradiation light of the target unit is longer than the peak wavelength of the sunlight spectrum, it becomes easy to distinguish the irradiation light from the target unit and sunlight, and the target in the image captured by the imaging unit Department becomes clear. As a result, the target portion can be accurately identified, and the shake can be detected more accurately.

Further, the light emission intensity per unit area of the LED array element has a strength that saturates at a level equal to or higher than the minimum sensitivity of the imaging element of the imaging unit and is stronger than outside light in the case of the maximum stroke L _MAX. .
According to this configuration, when the light emission intensity per unit area of the LED array element is the maximum stroke L _MAX , the intensity is saturated at or above the minimum sensitivity of the imaging element of the imaging unit and is stronger than the external light. This irradiation light can reach the image sensor of the imaging unit. Moreover, the output can be increased and irradiation light with sufficient intensity can reach the image pickup device of the image pickup unit without being restricted by the light emission intensity unlike the laser semiconductor.

Furthermore, the crane according to the present invention includes the crane body, a hanging tool suspended from the crane body, and any one of the crane runout sensors.
According to this configuration, since any one of the crane shake sensors described above is provided, it is possible to accurately detect the swing of the hanger without complicating the overall configuration. Further, it is possible to appropriately control the swing of the hanging tool based on the detection result.

According to the crane shake sensor according to the present invention, the shake can be accurately detected with a simple configuration.
In addition, according to the crane of the present invention, it is possible to accurately detect the swing of the hoist without complicating the overall configuration.

1 is a schematic configuration diagram of a crane runout sensor 1 according to an embodiment of the present invention. It is a schematic structure enlarged view of the image pick-up part 10 concerning the embodiment of the present invention. It is a schematic structure enlarged view of the target part 20 which concerns on embodiment of this invention. It is a graph which shows the relationship between the light emission wavelength band n and the solar spectrum S of the LED array element 21 which concerns on embodiment of this invention. It is a schematic block diagram of the crane run-out sensor 1 which concerns on embodiment of this invention, Comprising: The hanging tool W has displaced the state from the state of FIG.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a crane shake sensor 1 according to an embodiment of the present invention.
As shown in FIG. 1, the crane runout sensor 1 is disposed on a crane body C and a hanging tool W suspended from the crane body C, and the swing angle θ of the hanging tool W (see FIG. 5). Is detected. The crane body C and the suspension tool W can be relatively displaced in the vertical direction.
The crane shake sensor 1 includes four pairs of an imaging unit 10 and a target unit 20 that form a pair.

FIG. 2 is an enlarged schematic diagram of the imaging unit 10.
The imaging unit 10 is disposed below the crane body C and includes a camera 11, an optical lens 12, and an optical filter 13.

The camera 11 is being fixed to the lower surface c1 of the crane main body C in the state which faced the downward direction of the crane main body C, as shown in FIG. Each camera 11 is electrically connected to an image processing device (not shown), and transfers image data to the image processing device (not shown).

The optical lens 12 is fixed below the camera 11 and has a focal length f of, for example, 30 mm. The optical lens 12 has the entire upper projection surface of the target unit 20 paired with the camera 11 within the viewing angle of the camera 11 even when the crane body C and the suspension tool W are the farthest and closest. Can have a viewing angle α.
When the optical lens 12 is driven by a lens driving device (not shown), an image of the focused target unit 20 is sent to the camera 11.

The optical filter 13 reduces the influence of sunlight, and the transmission wavelength band bf (see FIG. 4) is designed based on the emission wavelength band n of the irradiation light from the target unit 20. Specifically, the center of the transmission wavelength band bf is designed to overlap the peak of the emission wavelength band n of the irradiation light from the LED array element 21 described later, and the transmission wavelength band bf becomes relatively narrow. Yes.

FIG. 3 is an enlarged schematic view of the target unit 20.
As shown in FIG. 3, each target unit 20 includes an LED array element 21 and a lens 22.

The LED array element 21 is one in which sixty LED bare chips (AlGaAs) are mounted in an array on a single AIN ceramic substrate and covered with a clear silicon resin. In this LED array element 21, sixty LED bare chips are gathered in a substantially circular and dense manner, and a light emitting surface 21a having a shape suitable for calculating the center of gravity (for example, a circular shape) is formed as a whole. .
In addition, if the number of LED bare chips is plural, it can be changed as appropriate.

Two or more LED array elements 21 are disposed at least at the four corners of the rectangular upper surface (upper part) w1 of the hanger W, and face the paired imaging units 10, and irradiate upward. It comes to emit light. The irradiation angle of the irradiation light of the LED array element 21 is +60 degrees to −60 degrees when the vertical axis is 0 degrees. Note that the irradiation angle of the irradiation light can be changed as appropriate.

FIG. 4 is a graph showing the relationship between the emission wavelength band n of the LED array element 21 and the solar spectrum S.
As shown in FIG. 4, the emission wavelength band n of the LED array element 21 is set to be longer than the peak wavelength of the solar spectrum S. More specifically, it is set to the wavelength region of the atmospheric absorption line in the near infrared region where the light intensity of sunlight is relatively low. More specifically, the emission wavelength band n of the LED array element 21 is set in the range of 700 nm to 1000 nm.
The light emission intensity per unit area of the LED array element 21 is the maximum stroke L _MAX (described later) between the target unit 20 and the imaging unit 10 when the crane body C and the hanging tool W are farthest from each other. In addition, the intensity is saturated at or above the minimum sensitivity of the image sensor of the camera 11 and is stronger than sunlight.
Since the LED array element 21 is one element, the drive circuit for the LED array element 21 is relatively simplified.

Returning to FIG. 3, the lens 22 is specifically composed of a condenser lens and is fixed above the LED array element 21. The lens 22 condenses and uniformizes the irradiation light emitted from the LED array element 21. The lens 22 enlarges the light emitting surface 21a of the LED array element 21 and projects it upward. More specifically, the illumination light emitted from the LED array element 21 at an irradiation angle of +60 degrees to −60 degrees is collected upward by the lens 22 at a predetermined projection angle β that satisfies the following expression (2). Project.

The stroke L between the target unit 20 and the imaging unit 10 is such that the maximum stroke L _MAX when the crane main body C and the lifting tool W are farthest is 40 m, and the minimum stroke L _MIN when the crane body C is closest is 3 m. Is set to

In the crane shake sensor 1, the radius of the light emitting surface 21 a of the LED array element 21 is d, the maximum stroke between the LED array element 21 and the camera 11 is L _MAX , and the instantaneous viewing angle of the imaging element of the camera 11 is Q Furthermore, the relationship of the following formula | equation (1) is satisfy | filled.
Q × L _MAX <d (1)
In the present embodiment, the size of the image sensor of the camera 11 described above is 10 × 10 μm, the focal length f of the optical lens 12 is 30 mm, and the instantaneous viewing angle Q is 0.33 mrad. That is, in this embodiment, since the maximum stroke L _MAX is 40 m, the diameter (light emitting area diameter) of the LED array element 21 is 1.3 cm or more.
However, even in the case of minimum stroke _{L MIN,} so that the entire LED array device 21 is imaged, the diameter of the LED array device 21 (light emitting area diameter) is set smaller than the viewing angle α in the case of minimum stroke _{L MIN} ing.

FIG. 5 is a schematic configuration diagram of the crane shake sensor 1 when the suspension tool W is shaken.
The projection angle β of the lens 22 satisfies the relationship of the following formula (2), where X is the maximum shake amount of the hanging tool W in the horizontal direction.
X / L <β / 2 Formula (2)
In this embodiment, the maximum shake amount X = ± 8.5 m when the stroke L = 40 m is set as a reference, and the projection angle β is +12 degrees to −12 degrees. That is, irradiation light emitted at an irradiation angle of +60 degrees to −60 degrees is projected by the lens 22 at +12 degrees to −12 degrees.

The crane shake sensor 1 having the above-described configuration images the target unit 20 paired by each imaging unit 10, and performs the image processing based on the composite image information of the captured target unit 20 to obtain the center of gravity of each LED array element 21. The position is calculated, and the deflection angle θ (see FIG. 5) is detected based on the temporal change in the position of the center of gravity.

According to the crane shake sensor 1 having the above-described configuration, since the target unit 20 including the LED array element 21 in which the light emitting surface 21a is formed by a plurality of LED chips arranged in an array is provided, the light source of the target unit 20 is a single light source. It is comprised with the element of. Thereby, since the structure of the drive circuit which controls the target part 20 can be simplified, the structure of the crane runout sensor 1 whole can be simplified.
Furthermore, by simplifying the configuration of the drive circuit that controls the target unit 20, it is possible to reduce administrative and operational labor and costs. That is, in the prior art, if a part of the element breaks down, an error occurs in the detection of the center of gravity of the target. Therefore, it takes time to perform maintenance and inspection work for normally lighting a plurality of elements.
On the other hand, according to the crane run-out sensor 1, since the LED array element 21 is one element, if the failure occurs, the entire LED array element 21 may be replaced, and maintenance work becomes easy. Thereby, it becomes possible to reduce the labor and cost accompanying a maintenance inspection work.

Moreover, according to the said structure, since sufficient light emission area of the target part 20 is ensured by satisfy | filling the relationship of Formula (1) mentioned above, even if it is a case where the weather is rain or fog, from the target part 20 Any one of the above will reach each imaging element of the imaging unit 10, and erroneous detection of the target unit 20 can be suppressed.
In other words, in the conventional technology using a semiconductor laser element in the target portion, the light emitting element has a large light emission intensity per unit area but a small light emitting area, so that the light emitting optical axis is blocked in the case of rain, fog, etc. A false detection occurred. In addition, in the conventional technology, an LED in which one element is resin-molded, such as a shell type, is used as a light source of the target unit, so that the light emission intensity per unit area and the light emission area of the light emitting element are small. In this case, the light-emitting optical axis was blocked and erroneous detection occurred.
However, since the sufficient light emitting area is secured in the target unit 20 of the crane shake sensor 1 as described above, the light emitting source size is increased. Thereby, even if the weather is rain or fog, the target shape to be imaged can be stabilized.

Also, since the lens 22 that collects and equalizes the irradiation light emitted from the target unit 20 is provided, the irradiation light can reach the image sensor without being diffused. That is, if the irradiation light is diffused, the ratio of the irradiation light reaching the camera 11 is reduced and the luminance needs to be increased. However, since the irradiation light is condensed and uniformed by the lens 22, the light emitting surface 21a. It is possible to increase the proportion of the irradiation light that reaches the camera 11 while suppressing an increase in the brightness of the camera 11.

Further, since the relationship of the above-described formula (2) is satisfied, for example, even if the hanging tool W is displaced due to shaking, the target unit 20 does not deviate from the imaging range of the imaging unit 10 and the target unit 20 captures an image on the imaging unit 10. Will be. Thereby, the erroneous detection which arises when the target part 20 remove | deviates from the imaging range of the imaging part 10 can be suppressed.
In addition, in the case where a semiconductor laser element is used for the target portion, the projection angle is different between the horizontal direction and the vertical direction. Therefore, in order to make the projection angle uniform in both directions, it is necessary to configure a special optical system. It was.
On the other hand, in the target unit 20 of the crane shake sensor 1, since the LED array element 21 is used as described above, a simple optical system is used to project in both directions in the horizontal direction and the vertical direction. It is possible to control the projection angle β.

Moreover, since the light emission wavelength band n of the LED array element 21 is set in the near infrared region where the light intensity of sunlight is relatively low, it becomes easy to distinguish the irradiation light from the target unit 20 and sunlight. In the image captured by the imaging unit 10, the target unit 20 becomes clear. As a result, the target unit 20 can be accurately identified, and the shake can be accurately detected.
Furthermore, since the emission wavelength band n of the LED array element 21 is set to the wavelength range of the atmospheric absorption line in the near infrared range, it is less susceptible to sunlight and more accurately detects vibration. It becomes possible.

Here, in the case of using an optical filter that transmits only irradiation light, in order to reduce the influence of sunlight, a filter characteristic with a narrow transmission wavelength band and a high transmittance in the wavelength band is good.
In the conventional technique using a semiconductor laser element as a target portion, the oscillation wavelength band of the irradiation light of the semiconductor laser element is very narrow, and therefore the transmission wavelength band of the optical filter needs to be very narrow. In general, as the transmission wavelength band of the optical filter becomes narrower, it becomes more difficult to manufacture the center wavelength constant, and the yield deteriorates. For this reason, it is necessary to confirm the oscillation wavelength for each semiconductor laser element and select an optical filter corresponding to the wavelength.
However, since the center wavelength of the oscillation wavelength of the semiconductor laser element changes according to the element temperature, there is a high possibility that the wavelength of the irradiation light will be out of the transmission wavelength band of the optical filter. If the wavelength of the irradiation light deviates from the transmission wavelength band of the optical filter, most of the irradiation light is blocked by the optical filter, and the irradiation light received by the image sensor of the camera 11 becomes slight. End up.
On the other hand, since the LED array element 21 described above has a wider emission wavelength band than the semiconductor laser element, the transmission wavelength band of the optical filter 13 can be easily managed. That is, since the wavelength band of the irradiation light becomes wide, even if the center wavelength of the optical filter is shifted in the manufacturing process (indicated by symbols bf ′ and bf ″ in FIG. 4), the light reception on the imaging unit 10 side. Large fluctuations in the amount of light are eliminated, and erroneous detection of the target unit 20 can be suppressed. In other words, since the LED array element 21 having a wide emission wavelength band is used for the target unit 20, it is not necessary to select the optical filter 13.

In addition, when the light emission intensity per unit area of the LED array element 21 is the maximum stroke L _MAX , the intensity is saturated at or above the minimum sensitivity of the imaging element of the imaging unit 10 and stronger than the external light. Irradiation light can reach the image sensor of the imaging unit 10.

Here, the detection rate of the imaging unit 10 improves as the brightness of the light source of the target unit increases.
In a conventional technique using a semiconductor laser element as a target portion, it is necessary to take safety measures from the viewpoint of eye protection in order to increase the luminance beyond the laser class determined by the JIS standard.
On the other hand, the LED array element 21 can increase the output and reach the imaging element of the imaging unit 10 with sufficient output without being restricted by the emission intensity.

Moreover, since the LED array element 21 uses an LED chip, it has the following advantageous effects as compared with a target using a semiconductor laser element. First, the LED array element 21 is more resistant to heat and impact than the semiconductor laser element. For this reason, since it is not necessary to take measures against heat and impact, the weight can be reduced as compared with a target using a semiconductor laser element. Secondly, the LED array element 21 is more excellent in stability and electrical stability with respect to the external environment than the semiconductor laser element. For this reason, it becomes a long life and can obtain the outstanding operativity.
Furthermore, the crane according to the present invention includes the crane body, a hanging tool suspended from the crane body, and any one of the crane runout sensors.

Further, according to the crane including the crane runout sensor 1 as described above, the runout of the hoisting tool W can be accurately detected without complicating the overall configuration. Further, it is possible to appropriately control the swing of the hanging tool W based on the detection result.

Note that the operation procedure shown in the above-described embodiment, various shapes and combinations of the constituent members, and the like are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
For example, in the above-described embodiment, the light emitting surface 21a of the LED array element 21 is formed in a circular shape so that the center of gravity can be easily calculated, but may be in other shapes (for example, square, regular polygon, rectangular shape). Good. In these cases, by setting d in the formula (1) as the shortest distance from the center of gravity of the light emitting surface of the target to the edge, even if the weather is rain or fog, the irradiation light from the target unit is imaged. The element can be reached.

In the above-described embodiment, the type of crane is not particularly mentioned, but the present invention can be applied to a movable type or a derrick including a fixed type.

Since the configuration of the drive circuit that controls the target unit can be simplified, the configuration of the entire crane runout sensor can be simplified. Further, even if the weather is rain or fog, any irradiation light from the target unit reaches each imaging element of the imaging unit, so that erroneous detection of the target unit can be suppressed.

DESCRIPTION OF SYMBOLS 1 Crane shake sensor 10 Imaging part 11 Camera 12 Optical lens 13 Optical filter 20 Target part 21 LED array element 21a Light emission surface 22 Lens C Crane main body d Radius of light emission surface (the shortest distance from the gravity center of the light emission surface of a target part to an edge)
L Stroke L _MAX Maximum Stroke Q Instantaneous Viewing Angle W Lifting Tool X Maximum amount of swinging of the lifting tool W in the horizontal direction

Claims

An imaging unit installed downward on the crane body;
An LED array which is provided on a hanging tool suspended from the crane body, has a plurality of LED chips arranged in an array, and emits irradiation light upward from a light emitting surface formed by the plurality of LED chips. A target portion having an element,
When the shortest distance from the center of gravity of the light emitting surface of the target unit to the edge is d, the maximum stroke between the imaging unit and the target unit is L MAX , and the instantaneous viewing angle of the imaging device of the imaging unit is Q A crane runout sensor satisfying the following relationship:
Q x L MAX <d
2. The crane shake sensor according to claim 1, wherein the target unit includes a lens that collects and equalizes the irradiation light emitted from the LED array element.
3. The crane shake sensor according to claim 2, wherein the following relation is satisfied, where X is a maximum shake amount in each stroke of the suspension tool in the horizontal direction and P is a projection angle of the lens.
X / L <P / 2
The crane shake sensor according to any one of claims 1 to 3, wherein a wavelength of irradiation light of the LED array element is longer than a peak wavelength of a sunlight spectrum.
The light emission intensity per unit area of the LED array element has a strength that saturates at or above a minimum sensitivity of the image pickup device of the image pickup unit and is stronger than outside light in the case of the maximum stroke L MAX. The crane runout sensor according to any one of 1 to 4.
The crane body;
A hanging tool suspended from the crane body;
A crane comprising the crane runout sensor according to any one of claims 1 to 5.