CN113490635A

CN113490635A - Crane and stacking method thereof

Info

Publication number: CN113490635A
Application number: CN202080010964.8A
Authority: CN
Inventors: 吉冈伸郎
Original assignee: Sumitomo Heavy Industries Material Handling Systems Co Ltd
Current assignee: Sumitomo Heavy Industries Material Handling Systems Co Ltd
Priority date: 2019-03-08
Filing date: 2020-02-07
Publication date: 2021-10-08
Also published as: JP2020142914A; WO2020184025A1; JP7162555B2

Abstract

The crane according to the present invention is a crane for stacking cargoes, the crane including: a spreader to hold the cargo; a trolley for suspending the hanger via the suspension member; a girder supporting the trolley to be capable of traversing; a traveling unit that supports the girder so as to be capable of traveling and has a tire; a photographing part which is arranged on the lifting appliance and acquires an image below the lifting appliance; a distance acquisition unit that is provided on the hanger and acquires a distance of a specific portion in the image acquired by the image acquisition unit; and a detection unit that detects the object to be detected at the target stacking position of the load held by the crane, based on the image acquired by the imaging unit and the distance acquired by the distance acquisition unit.

Description

Crane and stacking method thereof

Technical Field

The invention relates to a crane and a stacking method of the crane.

Background

As a conventional crane, a crane described in patent document 1 is known. The crane moves the spreader in a horizontal direction and lifts the cargo with the spreader. The crane is provided with: a girder extending in a traverse direction; a pair of leg portions supporting the girder; a traveling unit configured to support the leg unit so as to be capable of traveling; and the trolley suspends the lifting appliance and transversely moves along the girder. The traveling unit has a tire. The crane stacks the suspended cargo held by the hoist onto the existing stacked cargo.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-239343

Disclosure of Invention

Technical problem to be solved by the invention

Here, when the traveling unit includes a tire as in the crane, the crane can travel freely in the yard, but the position of the crane is likely to be displaced accordingly. Therefore, when the goods are stacked by the crane, the existing stacked goods may be offset from each other. Therefore, the crane is required to cope with such shifting of the stacked goods from each other when newly stacking the goods.

The invention aims to provide a crane and a stacking method of the crane, which can cope with the deviation of stacked goods when newly stacking the goods.

Means for solving the technical problem

A crane according to an embodiment of the present invention is a crane for stacking cargoes, the crane including: a spreader to hold the cargo; a trolley for suspending the hanger via the suspension member; a girder supporting the trolley to be capable of traversing; a traveling unit that supports the girder so as to be capable of traveling and has a tire; a photographing part which is arranged on the lifting appliance and acquires an image below the lifting appliance; a distance acquisition unit that is provided on the hanger and acquires a distance of a specific portion in the image acquired by the image acquisition unit; and a detection unit that detects the object to be detected at the target stacking position of the load held by the crane, based on the image acquired by the imaging unit and the distance acquired by the distance acquisition unit.

The crane can stack the suspended load on the existing stacked load by traversing the carriage in a state where the load is held by the crane at a destination of movement to which the carriage is moved by the traveling unit having the tire. The crane further includes an imaging unit provided on the hoist and configured to acquire an image of a lower portion of the hoist. Therefore, the crane can acquire an image of the existing stacked cargo located below the spreader by the image capturing unit. Here, the suspended load held by the hoist is stacked on the uppermost stacked load among the stacked loads. Therefore, the detection object that becomes the stacking target position of the suspended load held by the hoist can be detected based on the image acquired by the imaging unit. However, the detection unit may not be able to accurately determine whether the specific portion of the cargo in the image is the top stacked cargo or the lower cargo, simply by the image. In contrast, the crane includes a distance acquisition unit that is provided on the hoist and acquires the distance of the specific portion in the image acquired by the imaging unit. Therefore, by acquiring the distance of the specific portion in the image using the distance acquisition unit, the detection unit can grasp whether the specific portion is the top stacked cargo or the lower stacked cargo, and can accurately specify the detection target object. This makes it possible to cope with the displacement of the stacked cargo when newly stacking the cargo.

The distance acquisition section may be a two-dimensional laser scanner. In this case, the distance acquiring unit can acquire the distance of the specific part of the stacked cargo in the image without moving the spreader.

The distance acquisition unit may perform scanning in a traverse direction in which the carriage traverses. Thus, the distance acquiring unit can acquire the distance of the specific part of the stacked cargo in the image without moving the spreader in the lateral movement direction.

When the detection unit fails to detect the detection target object, the hoist can be moved toward the load held by the hoist with the imaging unit as a reference. At this time, the image capturing unit can acquire an image of a specific portion of the uppermost stacked cargo that is originally blocked by the suspended cargo.

One embodiment of the present invention relates to a method for stacking a load by using a crane, the crane including: a spreader to hold the cargo; a trolley for suspending the hanger via the suspension member; a girder supporting the trolley to be capable of traversing; and a traveling unit that supports the girder so as to be capable of traveling and has tires, the method for stacking a crane includes: a photographing process for obtaining an image below the lifting appliance; a distance acquisition step of acquiring a distance of a specific portion in the image acquired in the photographing step; and a detection step of detecting the object to be detected which is the target position for stacking the loads held by the hoist, based on the image acquired in the photographing step and the distance acquired in the distance acquisition step.

The stacking method of the crane can also obtain the same action and effect as the crane.

Effects of the invention

According to the present invention, there are provided a crane and a method of stacking the crane, which can cope with a deviation of stacked goods when newly stacking the goods.

Drawings

Fig. 1 is a block diagram of a crane according to an embodiment of the present invention.

Fig. 2 is a perspective view showing a crane body.

Fig. 3 is a perspective view showing the structure of the periphery of the spreader 22 in detail.

Fig. 4 is a schematic view showing a case where a stacked container as an object to be detected is detected.

Fig. 5 is a flowchart showing the control processing contents of the crane stacking method.

Fig. 6 is a schematic view showing a case where the crane according to the comparative example is used for stacking.

Detailed Description

Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and redundant description thereof is omitted.

A crane 100 according to an embodiment of the present invention will be described with reference to fig. 1 and 2. Fig. 1 is a block diagram of a crane 100 according to an embodiment of the present invention. Fig. 2 is a perspective view showing the crane body 20. As shown in fig. 1, the crane 100 includes a crane main body 20 and a control device 50.

As shown in fig. 2, the crane body 20 is of a portal type. The crane body 20 is, for example, a crane body that loads and unloads the container C on a container yard of a container terminal where the container C is transferred to and from an onshore container ship. A traffic lane (i.e., a loading/unloading lane) for transferring the trailer 10 or the like of the container C is laid in the container yard CY. The crane body 20 automatically transfers the container C to, for example, the trailer 10 parked on the loading/unloading lane. The crane body 20 takes a container C carried in by the trailer 10 from the trailer 10 and places the container C at a predetermined position of the container yard CY. The crane body 20 takes in the container C placed in the container yard CY, places the container C on the trailer 10, and allows the trailer 10 to carry out the container C to the outside.

The crane body 20 includes a crane body 21 and a spreader 22. The crane main body 21 can travel by a traveling unit 25 having a wheel with a tire. The traveling motor drives the traveling unit 25 to travel. The crane body 21 includes two pairs of

leg portions

26 and 26 erected on the traveling portion 25. The crane main body 21 is formed into a substantially portal shape by being provided with

girders

27, 27 that connect upper end portions of the

leg portions

26, 26. The crane main body 21 further includes a carriage 28 that can traverse the girder 27 in a direction orthogonal to the traveling direction. The carriage 28 is driven by a traverse motor to perform traverse. The cart 28 includes a scroll driving unit 29 including a spool driving motor and a spool that is rotated forward and backward by the spool driving motor. The trolley 28 suspends the spreader 22 via a suspension member 30 composed of a wire rope. The spreader 22 has a shape extending in the traveling direction. The suspension members 30 extend from two locations in the traveling direction of the trolley 28, and the spreader 22 is suspended by the suspension members 30 at two locations in the traveling direction.

As shown in fig. 1, the traveling motor of the traveling unit 25 and the traverse motor of the carriage 28 are controlled by a control device 50. And, the roll driving motor of the scroll driving part 29 is controlled by the control device 50.

The spreader 22 is a device for holding and lifting the container C. The spreader 22 can grasp the container C from the upper surface side of the container C and lift the container C by grasping it, thereby loading and unloading the container C. The hanger 22 is suspended via a rope pulley 33 around which a suspension member 30 from the scroll driver 29 is wound, and can be raised and lowered by forward and reverse rotation of the scroll driver 29. The spreader 22 is controlled by the control device 50.

The spreader 22 has substantially the same shape as the shape of the upper surface of the container C in plan view. A rope sheave 33 around which the suspension member 30 is wound is provided above the center of the spreader 22 in the longitudinal direction. When a container C is gripped by the spreader 22, the spreader 22 is positioned above the container C. The spreader 22 includes guides 32 and locking pins (not shown). When the spreader 22 is lowered in order to pick up a target container C to be picked up by the spreader 22, the guide 43 guides the spreader 22 onto the target container C. The guides 32 are provided near both ends in the longitudinal direction of one end portion and the other end portion in the width direction of the spreader 22 in the horizontal direction, respectively.

The spreader 22 holds the container C on the trailer 10 while discharging the container C transported by the trailer 10 to the container yard CY. Thereafter, the spreader 22 deposits the held containers C on the container yard CY according to a predetermined schedule. The spreader 22 lifts the held container C from the trailer 10 and moves it in a lateral direction so as to be stacked on the ground of the container yard CY or on an existing stacked container C. In the following description, XY coordinates are sometimes used for description. At this time, the traveling direction of the traveling unit 25 is defined as the X-axis direction, and the lateral moving direction in which the carriage 28 moves laterally is defined as the Y-axis direction. The front side of the trailer 10 is defined as the positive side in the X-axis direction, and the side away from the trailer 10 is defined as the positive side in the Y-axis direction.

When the spreader 22 is raised after holding the container C on the trailer 10, the spreader 22 moves to the upper side of the planned target position in the Y axis direction together with the trolley 28 by the automatic operation. Here, when the spreader 22 drops the container C and stacks the container C at the target position, the crane 100 inspects the periphery of the target position and then performs stacking in order to avoid the occurrence of deviation. Specifically, as shown in fig. 3, when the crane 100 stacks the held container C on the existing second-tier stacked container C, the crane detects the second-tier stacked container C as the detection target object to acquire the position information of the detection target object, and then lowers the spreader 22, thereby accurately stacking the held container C.

For convenience of explanation, the container C held by the spreader 22 is referred to as a suspended container C1, and the existing stacked containers C are referred to as stacked containers C2 and C3. The stacking container C2 is a first layer stacking container, and the stacking container C3 is a second layer stacking container. At this time, the container C3 becomes the object to be detected. In order to detect the stack container C3 as the detection target object, the crane main body 20 includes a camera 40 (image pickup unit) and a distance meter 41 (distance acquisition unit).

The camera 40 is a device that is disposed on the spreader 22 and acquires an image below the spreader 22. In the example shown in fig. 3, the camera 40 is provided at the end on the negative side in the Y-axis direction of the spreader 22. That is, the camera 40 is disposed on the downstream side (the negative side in the Y-axis direction) in the moving direction from the suspended container C1 held by the spreader 22. Thereby, the camera 40 can acquire an image in the vicinity of the edge E1 on the negative side in the Y axis direction of the stack container C3 as the detection target object. The cameras 40 are provided in the vicinity of both ends of the spreader 22 in the X axis direction, that is, a pair of cameras is provided. Therefore, the pair of cameras 40 can acquire images of the vicinities of the ends in the X-axis direction of the edge portion E1 of the stack container C3, respectively.

Specifically, the camera 40 can acquire an image of a portion indicated by the photographing region PH in fig. 3. Fig. 3 shows the photographic area PH up to the height position of the upper surface of the stack container C3, but the portion of the photographic area PH that overflows from the stack container C3 extends further downward. That is, the portion of the photographing region PH covering the upper surface of the stack container C3 can acquire an image indicating a situation in the vicinity of the edge portion E1 of the stack container C3, and the portion of the photographing region PH on the outer side of the edge portion E1 can acquire an image indicating a situation below the upper surface of the stack container C3. In fig. 3, the stack container C3 is slightly shifted to the positive side in the Y-axis direction with respect to the stack container C2, and therefore the upper surface of the stack container C2 is slightly exposed. Therefore, the image of the camera 40 includes a portion indicated by "a" in the edge portion E2 of the stack container C2.

The distance meter 41 is a device that is provided on the hoist 22 and acquires the distance of a specific part in the image acquired by the camera 40. In the example shown in fig. 3, the distance meter 41 is provided at the end on the negative side in the Y-axis direction of the spreader 22. That is, the distance meter 41 is disposed on the downstream side (the negative side in the Y-axis direction) in the movement direction from the suspended container C1 held by the spreader 22. The pair of distance meters 41 are disposed adjacent to the pair of cameras 40, respectively. Thereby, the distance meter 41 can measure the distance of an arbitrary portion in the image of the camera 40. The distance means: the distance from the position where the distance meter 41 is installed to the site to be measured. The distance meter 41 measures the distance between the edge portion EX or the upper surface of the stack container CX in the image. In addition, the expression "stack container CX" means that "stack container C2" is not distinguished (or cannot be distinguished) from "stack container C3". Similarly, the expression "edge portion EX" means that the "edge portion E1" and the "edge portion E2" are not distinguished from each other.

As the distance meter 41, a laser distance meter may be used. Further, as the laser range finder, a single-axis laser range finder may be used, or a two-dimensional laser scanner may be used. When the optical axis LA is set in the case of using the single-axis laser range finder, the optical axis LA is fixed and cannot move. Therefore, when the distance of the edge portion EX of the stacked container CX is measured by the distance meter 41, the spreader 22 needs to be moved so that the edge portion EX comes on the optical axis LA. When a two-dimensional laser scanner is used as the distance meter 41, the optical axis LA can be moved to perform scanning. Here, the distance meter 41 preferably scans in the Y-axis direction. At this time, even when the edge portion EX is not directly below the distance meter 41, the distance of the edge portion EX can be acquired by scanning the optical axis LA in the Y-axis direction by the distance meter 41.

As shown in fig. 1, the control device 50 is a general-purpose computer including a processor, a memory, a storage device, a communication interface, and a user interface. The processor is an arithmetic Unit such as a CPU (Central Processing Unit). The Memory is a storage medium such as a ROM (Read Only Memory) or a RAM (Random Access Memory). The storage device is a storage medium such as an HDD (Hard Disk Drive). The communication interface is a communication device that implements data communication. The user interface is an output device such as a liquid crystal display or a speaker, and an input device such as a joystick, a button, a keyboard, a touch panel, or a microphone. The processor centrally controls the memory, storage, communication interface, and user interface to implement the functions described below. In the control device 50, for example, a program stored in the ROM is loaded into the RAM and the CPU is caused to execute the program loaded into the RAM to thereby realize various functions. The control device 50 may be constituted by a plurality of computers.

The control device 50 is a device for collectively controlling the entire crane 100. The control device 50 includes an arithmetic unit 51, a crane control unit 52, a detection unit 53, and a storage unit 54.

The arithmetic unit 51 performs various arithmetic operations necessary for controlling the crane 100. The calculation unit 51 calculates the operation when the container C is gripped by the spreader 22, the transport position of the container C, and the like. The crane control unit 52 controls the operation of the crane 100. The crane control unit 52 sends control signals to the travel motor of the travel unit 25 and the traverse motor of the carriage 28 to control the horizontal movement of the spreader 22. The crane control unit 52 sends a control signal to the reel drive motor of the roll driving unit 29 to control the operation of lifting and lowering the spreader 22 via the suspension member 30.

The detection unit 53 detects the object to be detected which is the stacking target position of the container C held by the spreader 22, based on the image acquired by the camera 40 and the distance acquired by the distance meter 41. In the example shown in fig. 3, the detection unit 53 detects the stacker container C3 as the detection target object. The detection unit 53 determines that the container CX having the edge portion EX captured in the image is a candidate for the detection target. Then, the detection unit 53 acquires the distance between the edge EX or the upper surface of the container CX as the candidate detection target from the distance meter 41. When the distance is within the expected distance range, the detection unit 53 adopts the candidate detection target object as the main detection target object (for example, the state shown in fig. 4 (b)). That is, the detection unit 53 detects the detection target object (i.e., the stacker container C3). On the other hand, if the distance acquired by the distance meter 41 is not within the expected distance range, the detection unit 53 determines that the candidate detection target is not the actual detection target (for example, the state shown in fig. 4 (a)).

The storage unit 54 stores various parameters necessary for the detection unit 53 to detect the detection target object, for example. The storage unit 54 may store a stacking plan of the containers C when the crane 100 is automatically operated. The plan includes information (Stack Profile data) such as in which order the containers C newly arrived at the container yard CY are to be stacked. That is, the calculation unit 51 can specify which of the existing containers C the container C is placed on when the spreader 22 holds a new container C by referring to the schedule stored in the storage unit 54.

Next, the control processing contents based on the stacking method of the crane 100 according to the present embodiment will be described with reference to fig. 4 and 5. Fig. 4 is a schematic view showing a case where a stacked container C3 as an object to be detected is detected. Fig. 5 is a flowchart showing the control processing contents of the method for depositing the crane 100 according to the present embodiment.

As shown in fig. 5, the arithmetic unit 51 receives an instruction signal for stacking a container C newly arriving at the container yard CY by the automatic operation (step S10). At this time, the arithmetic unit 51 refers to the stacking plan data in the storage unit 54 to acquire the position information of the detection target object which becomes the stacking target position of the new container C. Here, the detection object suspending the container C1 becomes the second-tier stacking container C3. The position information includes, in addition to the position information of the inspection target object (i.e., the stack container C3) in the horizontal direction, height information H1 (see fig. 4) of the stack container C3.

Subsequently, the arithmetic unit 51 starts the automatic operation (step S20). The arithmetic unit 51 starts the automatic operation from the time when the container C1 is suspended by the hoist 22. Thereafter, the arithmetic unit 51 automatically conveys the suspended container C1 to the overhead of the inspection object (i.e., the stacked container C3) (step S30). The arithmetic unit 51 performs automatic control while monitoring the height position and the Y-axis direction position of the moving suspension container C1.

When the hanging container C1 comes over the inspection target object (i.e., the stacked container C3), the control device 50 starts processing for inspecting the stacked container C3 as the inspection target object in order to accurately grasp the position of the stacked container C3. In this process, a shift in the relative position between the suspension container C1 and the stacking container C3 can be detected. The height information H2 (see fig. 4) of the suspended container C1 at this time can be grasped from the position of the spreader 22 and the like.

First, the detection unit 53 specifies candidates of the detection target object from the image acquired by the camera 40 (step S40). The detection unit 53 extracts the edge portion EX from the image and specifies the container CX having the edge portion EX as a candidate of the detection target. Next, the detection unit 53 acquires the relative height of the container CX identified as the candidate of the detection target object from the distance meter 41 (step S50). Thereby, the detection unit 53 grasps the distance H3 (see fig. 4) between the distance meter 41 and the upper surface of the container CX.

Next, the detector 53 determines whether or not the formal inspection object (i.e., the container C3) is present in the image using the distance acquired in step S50 (step S60). The detection unit 53 compares the distance value acquired by the distance meter 41 with a predetermined threshold value, and performs the determination of step S60. For example, when the threshold ST is set, the detector 53 determines that the actual detection target is present in the image if the absolute value of "H2-H1-H3" is smaller than the threshold ST. Further, "H2 to H1" are relative distances set in advance, and therefore may be fixed values.

Next, the contents of steps S40 to S60 will be specifically described with reference to fig. 4 (a). For example, as shown by the broken line in fig. 4 (a), when the offset between the stack container C3 and the stack container C2 is small, the edge portion E2 of the stack container C2 and the edge portion E1 of the stack container C3 are included in the photographing region PH. Therefore, two edge portions EX are detected in the image. If such an image can be acquired, the detection unit 53 can estimate that the stack container C3 is shifted toward the positive side in the Y-axis direction, and therefore, the container CX corresponding to the edge EX on the positive side in the Y-axis direction is determined as a candidate of the detection target. Alternatively, when the stack container C3 and the stack container C2 are not shifted or the stack container C3 is shifted toward the negative side in the Y-axis direction, only the edge portion E1 of the stack container C3 is captured in the image, and therefore the detection unit 53 determines the container CX captured in the image as the candidate of the detection target object. In these cases, by performing the processing of steps S50 and S60, the detector 53 can detect the stacked container C3 as a formal inspection object.

If it is determined in step S60 that the formal inspection object is present in the image, the detector 53 can regard the detected position information of the stack container C3 as a normal detection value and can recognize that the stack container C3 is normally detected (step S70). After that, the arithmetic unit 51 stacks the suspension container C1 based on the position information of the stacked container C3 used in step S70 (step S80). This ends the processing shown in fig. 5. If a new container C enters the container yard CY, the process shown in fig. 5 is performed again.

On the other hand, as shown by a solid line in fig. 4 (a), when the amount of shift of the stack container C3 with respect to the stack container C2 is large, the edge portion E1 is shielded by the suspended container C1 and is not captured in the image. At this time, the detection unit 53 detects only the edge portion E2, and thus identifies the container C2 as a candidate for the detection target object. However, the distance H3 acquired by the distance meter 41 at this time is much larger than the normal value ((b) in fig. 4). Therefore, the absolute value of "H2-H1-H3" in step S60 is much larger than the threshold ST, and therefore the detector 53 determines that the formal detection target (i.e., the container C3) is not present in the image.

When it is determined in step S60 that the actual detection object does not exist in the image, the arithmetic unit 51 moves the spreader 22 to search for another detection object candidate and specify a new detection object candidate (step S90). In step S90, the arithmetic unit 51 moves the spreader 22 toward the suspended container C1 held by the spreader 22 with the camera 40 as a reference. That is, the spreader 22 is moved to the positive side in the Y-axis direction.

At this time, as shown in fig. 4 (b), by moving the spreader 22 to the positive side in the Y-axis direction, the edge portion E1 of the stack container C3 enters the photographing region and is photographed in the image. At this time, the detection unit 53 can estimate that the stacked container C3 is shifted toward the positive side in the Y-axis direction, and therefore, the container CX corresponding to the edge EX on the positive side in the Y-axis direction is determined as the candidate of the detection target.

When step S90 ends, the process of step S60 is repeated. In this case, in the example of fig. 4 (b), since the stack container C3 can be specified as a candidate for the detection target object, the presence of the stack container C3 in the image can be determined in the process of step S60.

In step S90, if the new candidate for the detection target cannot be identified even if the spreader 22 is moved by a certain amount toward the positive side in the Y-axis direction or the spreader 22 is moved in any direction, the arithmetic unit 51 may suspend the automatic operation. Alternatively, if the stack container C3 cannot be detected even if the loop of steps S90, S50, and S60 is repeated several times, the arithmetic unit 51 may suspend the automatic operation. After the pause, the operator may manually perform the stacking operation, or may check the condition of the container.

Next, the operation and effects of the crane 100 and the method for stacking the crane 100 according to the present embodiment will be described.

First, as a comparative example, a detection unit in the case where the distance meter 41 is not provided as shown in fig. 6 will be described. At this time, if the amount of displacement of the upper stack container C3 from the lower stack container C2 is large, the edge portion E1 of the stack container C3 becomes a blind spot of the hanging container C1, and is not captured in the image captured by the camera 40 moving from the negative side in the Y-axis direction. At this time, the detector erroneously detects the stack container C2 in the image as the detection target object (i.e., the stack container C3).

In contrast, the crane 100 according to the present embodiment can stack the suspended container C1 on the existing stacked container C3 by traversing the trolley 28 in a state where the container C is held by the crane 22 at the destination of movement to which the crane moves by the traveling unit 25 having tires. The crane 100 also has a camera 40 that is provided on the spreader 22 and acquires an image below the spreader 22. Thus, the crane 100 is able to acquire images of the existing stack container C3 located below the spreader 22 via the camera 40. Here, the suspended container C1 held by the spreader 22 is stacked on the uppermost stacked container C3 among the stacked containers C. Therefore, the detection target object which becomes the stacking target position of the suspended container C1 held by the hoist can be detected from the image acquired by the camera 40. However, it is difficult for the detection section 53 to accurately determine whether the specific part of the cargo in the image is the uppermost stacking container C3 or the lower stacking container C2, simply by the image. In contrast, the crane 100 includes a distance meter 41 that is provided on the spreader 22 and acquires the distance of a specific part in the image acquired by the camera 40. Therefore, by acquiring the distance of the specific portion in the image using the distance meter 41, the detection portion 53 can grasp whether the specific portion is the uppermost stack container C3 or the lower stack container C2, and can accurately specify the detection target object. This makes it possible to cope with the displacement of the stacked container C3 when a new suspended container C1 is stacked.

The range finder 41 may be a two-dimensional laser scanner. At this time, the distance meter 41 can acquire the distance of the specific portion of the stacking container CX in the image without moving the spreader 22.

The two-dimensional laser scanner (i.e., the range finder 41) can scan in the traverse direction in which the carriage 28 is traversed. Thus, the distance meter 41 can acquire the distance of the specific portion of the stacked container CX in the image without moving the spreader 22 in the traverse direction.

When the detection unit 53 fails to detect the detection target object, the spreader 22 may be moved toward the suspended container C1 held by the spreader 22 with the camera 40 as a reference. At this time, the camera 40 can acquire an image of a specific portion of the uppermost stacked container C3 that is originally blocked by the suspended container C1.

The present invention provides a method for stacking containers C by using a crane 100, the crane comprising: a spreader 22 holding a container C1; a trolley 28 for suspending the spreader 22 via a suspension member 30; a girder 27 supporting the carriage 28 to be capable of traversing; and a traveling unit 25 having tires and supporting the girder 27 to be capable of traveling, the method for stacking the crane 100 includes the steps of: a photographing step of acquiring an image below the hanger 22; a distance acquisition step of acquiring a distance of a specific portion in the image acquired in the photographing step; and a detection step of detecting the object to be detected which is the target position for stacking the loads held by the hoist, based on the image acquired in the photographing step and the distance acquired in the distance acquisition step.

The stacking method of the crane 100 can also obtain the same operational effects as the crane described above.

The present invention is not limited to the above-described embodiments.

For example, the distance meter 41 is not necessarily located adjacent to the camera 40, and the distance meter 41 is not necessarily directed directly downward, and may be disposed obliquely. At this time, it is preferable to correct the posture and position of the distance meter 41 by calculation and then apply the distance to the calculation.

For example, in the above-described embodiment, a distance meter using a laser is used as the distance acquisition unit. However, the distance acquiring unit is not particularly limited as long as it can acquire a distance. For example, a TOF Camera (Time of Flight Camera) in which a Camera and a range finder are integrated may be used. Further, a system in which a plurality of cameras are used to acquire a three-dimensional image may be employed to acquire an image and a distance at the same time. However, if the camera and the range finder are provided separately, the information acquired by the camera and the information acquired by the range finder can be compared, and therefore, a double confirmation effect can be obtained.

Description of the symbols

22-spreader, 25-running part, 27-girder, 28-trolley, 30-suspension part, 40-camera (camera part), 41-rangefinder (distance acquisition part), 53-detection part, 100-crane.

Claims

1. A crane for stacking cargoes, comprising:

a spreader holding the cargo;

a trolley for suspending the spreader via a suspension member;

a girder supporting the trolley to be capable of traversing;

a traveling unit that supports the girder so as to be capable of traveling and that has a tire;

a photographing unit which is provided on the hanger and acquires an image below the hanger;

a distance acquisition unit that is provided on the hanger and acquires a distance of a specific portion in the image acquired by the image acquisition unit; and

and a detection unit configured to detect an object to be detected which is a target position for stacking the loads held by the spreader, based on the image acquired by the imaging unit and the distance acquired by the distance acquisition unit.

2. A crane according to claim 1,

the distance acquisition unit is a two-dimensional laser scanner.

3. A crane according to claim 2,

the distance acquisition unit scans along a traversing direction in which the carriage traverses.

4. A crane according to any one of claims 1 to 3,

when the detection unit fails to detect the object to be detected, the hanger is moved toward the object held by the hanger with the imaging unit as a reference.

5. A method for stacking a load by using a crane, the crane comprising:

a spreader to hold the cargo;

a trolley for suspending the spreader via a suspension member;

a girder supporting the trolley to be capable of traversing;

a traveling unit that supports the girder so as to be capable of traveling and has a tire,

the method for stacking a crane is characterized by comprising the following steps:

a photographing process for acquiring an image below the hanger;

a distance acquisition step of acquiring a distance of a specific portion in the image acquired in the image capturing step; and

a detection step of detecting an object to be detected which is a target position for stacking the loads held by the hangers, based on the image acquired in the imaging step and the distance acquired in the distance acquisition step.