JPH11116060A - Container placed condition detection method for cargo handling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly control a cargo handling device by detecting a condition of a group of containers on a cargo bed of a truck. SOLUTION: A stocking port 1a for a truck 2 is preliminarily provided as X-Y plane coordinates data, a camera 10 provided on a cargo handling device 4 movable for run and traverse is moved to at least two diagonal corners on an upper surface of a whole body of a group of containers based on X-Y plane coordinates, and a space part surrounded by angles of four containers 3 is detected based on images picked up by the camera 10 at the two diagonal corners, center coordinates of the space part are determined based on results of detection, and the center coordinates are compared with the X-Y plane coordinates to detect a position of a whole body of the group of containers on a cargo bed of the truck 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for accurately detecting the position, height, and inclination of a group of containers when unloading a container containing fruits and vegetables loaded on a truck bed, for example, in a vegetable market. The present invention relates to a container loading state detection method for a cargo handling device capable of controlling the cargo handling device.

[0002]

2. Description of the Related Art Conventionally, loading and unloading operations for unloading containers from trucks are performed manually. Further, in order to improve the efficiency of unloading work by hand, the use of a cargo handling device has been studied.

[0003]

When loading or unloading a container, a truck bed having a plurality of containers stacked thereon has a truck bed and the uppermost layer of the container which rise or change in inclination. In addition, the amount of change differs for each vehicle type or individual truck. In such a situation, when carrying out the cargo handling work of the container using the cargo handling device, traveling of the cargo handling device,
If the clamping mechanism that moves in the horizontal direction and moves up and down is not accurately positioned with respect to the container group on the truck bed, there is a possibility that a malfunction may occur, such as a failure to grasp the container or drop the container at an unrelated part.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and a method of detecting a container placement state of a cargo handling device capable of accurately controlling by detecting the state of a group of containers on a truck bed. The purpose is to provide.

[0005]

In order to achieve the above object, the present invention has a storage location of a truck in advance as XY plane coordinate data.
The camera is coarsely moved based on the Y-plane coordinates, and the camera captures and detects a space portion surrounded by the corners of four containers located at least at two diagonal corners of the entire upper surface of the container group. The center coordinates of the portion are obtained, and the center coordinates are compared with the XY plane coordinates to detect the position of the entire container group on the truck bed. By doing so, the exact position of the container group can be detected.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has a place where a truck enters and leaves a vehicle as XY plane coordinate data in advance, and when a truck arrives within the XY plane coordinate, the truck enters the XY plane coordinate. An image captured by a camera provided on a cargo handling device that travels and traverses at least at two diagonal corners of the entire upper surface of the container group on the truck bed, and the camera takes images at each of the two diagonal corners After detecting the space portion surrounded by the corners of the four containers, the center coordinates of the space portion are respectively obtained based on the detection result, and these center coordinates are compared with the XY plane coordinates to determine the truck bed. The position of the entire container group above is detected.

Further, according to the present invention, in the above method, the camera is coarsely moved to three corners of the entire upper surface of the container group on the truck bed based on the XY plane coordinate data, and images are taken by the camera at each of these three corners. After detecting each of the space portions surrounded by the corners of the four containers from the image, the coordinates of each of the space portions are obtained based on the detection results, and when the camera is moved to another imaging point other than the three corners, Is the X in the three corners
-This is performed based on the Y coordinate.

Further, according to the present invention, in any one of the above methods, the camera is coarsely moved to at least two diagonal corners of the entire upper surface of the container group on the truck bed based on the XY plane coordinate data, At each of the two corners, a space portion surrounded by the corners of the four containers is detected from the image captured by the camera, the coordinates of each space portion are obtained based on the detection result, and then traveling and traverse movement are performed. The detecting means provided in the cargo handling device to be moved is radially moved from the center of the space surrounded by the corners of the four containers, and detects the heights to the corners of the containers to detect the height and inclination of the container group. Is what you do.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of an automatic cargo handling facility to which a method for detecting a container placement state of a cargo handling device of the present invention is applied. FIG. 2 shows the vicinity of the cargo handling device in the automatic cargo handling equipment. FIG. 3 is an enlarged view of a main part of a clamp mechanism in the automatic cargo handling equipment. FIG. 4 shows a state where a main part of the clamp mechanism in the automatic cargo handling equipment is viewed in plan. FIG. 5 shows a detection pattern shape of a corner portion of the container in the container loading state detection method of the cargo handling apparatus of the present invention. FIG. 6 shows the principle of detecting the center position of the space surrounded by four containers in the method for detecting the container placement state of the cargo handling device of the present invention. FIG. 7 shows the imaging points of the camera.

The container loading state detecting method of the cargo handling device according to the present invention is carried out by the automatic cargo handling device 1 shown in the figure. The automatic loading and unloading device 1 loads or unloads containers 3 from, for example, a truck 2 truck of a mini-vehicle equipped with pneumatic tires, and loads a pallet 1A on which the containers 3 unloaded from the truck 2 are placed. A roller table 1B to be placed, a conveyor 1C for transporting the container 3 from the roller table 1B to a predetermined location, and the like are provided.

Reference numeral 4 denotes a cargo handling device movably provided on two traveling beams 5 supported by columns 4a above the entire cargo handling position, and the cargo handling device 4 is guided by the traveling beams 5,5. Truck 7 moving in the traveling direction of the truck 2
And a transverse carriage 8 provided on a traveling carriage 7 movable in the traveling direction of the truck 2, and a clamp mechanism 9 that moves up and down from the transverse carriage 8. When driving the traveling carriage 7, the traversing carriage 8, and the clamp mechanism 9, each drive unit is controlled in accordance with an output from a control device (not shown), and performs a moving, lifting, lowering, gripping or releasing operation. Have been.

The clamp mechanism 9 clamps, for example, two containers 3 on the carrier of the truck 2 in the vertical direction and two containers in the horizontal direction, and lifts and transports the containers.
In order to unload onto the pallet 1A or to load four containers 3 collectively from the pallet 1A on the loading platform of the truck 2, the following configuration is adopted.

Reference numeral 11 denotes an elevating mechanism, for example, a winch arranged on the traversing carriage 8, and the elevating base 12 is held in a suspended state via a wire rope 11a wound or sent out by the winch 11. . And as a mechanism for guiding the elevation of the elevation base 12,
In the present invention, the pantograph mechanism 13 is employed. In the configuration of the present embodiment, the linear guide 13a is used for the slide portion of the pantograph mechanism 13.

Reference numeral 14 denotes a rotary base installed below the lifting base 12 via a horizontal rotary mechanism. As the horizontal rotation mechanism of the rotation base 14, in the configuration of the present embodiment, a pivot 15 is pivotally supported so as to be rotatable on the elevating base 12, and the pivot 15 is rotated by a power cylinder 16, for example. ing. Then, by attaching the rotation base 14 to the lower end of the pivot 15, the rotation base 14 rotates horizontally integrally with the pivot 15.

Reference numeral 17 denotes, for example, two pairs of air cylinders which are installed in the rotating base 14 in a hanging manner. In this embodiment, four pairs of the air cylinders 17 are installed. . Then, for example, a wire rope 1
Each of the clamp portions 19 is installed in a suspended manner through the respective portions 8.

The clamp section 19 has a configuration in which a pair of positioning air cylinders 19b and clamping air cylinders 19c are respectively arranged on a hand base 19a in a predetermined manner.
As shown in FIG. 4, 9b is disposed on a diagonal line of the container 3 in a plan view, and is used to push the opposing corners of the container 3 from the inside with an extrusion fitting 19d attached to the rod end in a projecting manner. Can be The clamping air cylinder 19c is arranged on the center line in the longitudinal direction of the container 3 in a plan view, and is used to engage the clamp claws 19e with both grips 3a provided on the container 3 from the inside.

Further, when the edge of the hand base 19a comes into contact with the container 3, the winch 11
And a limit switch S2 for stopping the lowering of the elevating base 12 and stopping the lowering of the elevating base 12, and a limit switch S2 for driving the winch 11 to elevate the elevating base 12 when the arm base end of the clamp claw 19e comes into contact.

Reference numeral 20 denotes a cylinder which is suspended from the elevating base 12, and the rod is fitted into a guide cylinder 21 which stands on the upper surface of the rotary base 14 at a position facing the rod of the cylinder 20. Thus, the rotation of the rotation base 14 is prevented.

The camera 10 used in carrying out the method of the present invention is provided with a holding member 10a projecting in the running direction from a center position in the traversing direction of a traversing base 8a holding each member of the traversing carriage 8. The optical axis is held so as to be directed vertically downward.

In the above configuration, the cargo handling operation of the container 3 is performed by controlling the driving of each part. In performing this control, it is necessary to accurately detect the position, height, and inclination of the container 3. By supplying the detected data to the control device (not shown), the target container 3 can be unloaded or loaded properly and efficiently.

Therefore, a container 3 according to the method of the present invention will be described below, for example, when carrying out a container unloading operation.
The procedure for detecting the position, height, and inclination of is described. First, as shown in FIG. 1, the automatic cargo handling equipment 1 is provided with a storage port 1a at a position where the truck 2 is stored, and the plane data of the storage port 1a is fixedly stored in a storage device (not shown) in advance. It is stored as XY plane coordinate data.

Here, for example, the truck 2 is the storage port 1
a when the truck 2 enters the storage port 1a slightly obliquely, a deviation occurs with respect to the XY plane coordinates. Assuming that the XY plane coordinates of each of the corners are each within a predetermined range of the XY plane coordinates, the camera 10 is coarsely moved toward one of the four corners of the container group.

Here, the predetermined range of the XY plane coordinates is the range of the imaging field of view of the camera 10, and it is considered that the corners of the container group are respectively located when the storage port 1a is viewed in plan. If a predetermined range is defined for each of the plane coordinates and the camera 10 is moved toward the center of the XY plane coordinates of the predetermined range, even if the truck 2 enters the storage port 1a obliquely, the storage port 1a , The corners of the container group can always be included in the field of view of the camera 10.

The image that enters the visual field of view by the camera 10 is binarized, and then the captured image is scanned to detect the corners of the container 3 based on the brightness of each pixel based on the binarized data. That is, at the time of scanning the captured image, the corners of the container 3 stored in the storage device in advance are shown in FIGS.
5D, pattern matching processing is performed on the four patterns shown in each of FIGS. 5A to 5C. That is, for example, the shapes shown in FIG. By detecting, the corners of the container 3 are detected one after another.

When all four corner patterns are detected in the captured image, a space surrounded by the corners of the four containers is detected. The center of this space is shown in FIG. Based on the principle, the average coordinates of the intersections Q1 to Q4 when the edges of the container 3 are extended in the X and Y directions are calculated and detected as the center coordinates, and this center is determined by the above XY.
Detect where it is located on the plane coordinates. That is, since the center coordinates of the imaging field of view of the camera 10 are the center coordinates of the XY plane coordinates within the predetermined range as described above, the center of the space surrounded by the corners of the four containers from the center of the imaging field of view. Is calculated by calculating how much each has moved in the X and Y directions, the position in the XY plane coordinates can be detected.

If the above procedure is performed on at least two diagonal corners of the entire upper surface of the container group on the truck bed, the storage state of the truck 2 with respect to the storage port 1a can be recognized.

Then, the clamp mechanism 9 is finely adjusted in the X and Y directions based on the position information of the container group, and the winch 11 is driven until the limit switch S1 is actuated to lower the elevating base 12 so as to lower the limit switch S1. Is operated and the winch 11 is stopped, and then the rod of the air cylinder 17 is protruded to position the air cylinder 19 for positioning.
b and the clamping air cylinder 19c are driven to hold the container 3. When the clamping air cylinder 19c is driven to open the clamp claw 19e, the base end of the arm of the clamp claw 19e comes into contact with the limit switch S2 to operate, whereby the winch 11 is driven to be wound and the lifting base is moved. Then, the cargo handling device 4 is moved to the pallet 1A, where the container 3 is placed.

The reason for driving the air cylinder 17 during the above operation is as follows. That is, although the position of the container group on the XY plane is detected by the above procedure, the entire container group may actually be inclined. The limit switch S1 is operated at the edge of the container 3 located at the uppermost position, and the pusher 19d and the clamp claw 1 are attached to the container 3 at the lowermost position.
9e may not be positioned correctly with respect to the container 3 and may fail to grasp the container 3 located at the lowermost position.

Therefore, in order to prevent the above-mentioned phenomenon, the limit switch S1 is actuated once by contact between the edge of the container 3 located at the inclined uppermost portion and the hand base 19a at a position corresponding to the container 3. Elevating base 1
2 is stopped, and the rod of the air cylinder 17 is protruded, so that the hand base 1
If 9a is in contact, the wire rope 18 bends; otherwise, the rod of the air cylinder 17 is protruded to allow the hand base 19a to contact the upper edge of the container 3 for the first time. By doing so, the pushing-out fitting 19d and the clamp claws 19e can be correctly positioned with respect to the four containers 3 grasped at a time even if the container group is inclined.

After unloading the four containers 3 located at the corners of the container group, the cargo unloading operation proceeds to the next unloading point calculated from the dimensions of the container 3 based on the position information of the container group. By moving the clamp mechanism 9 by the device 4 and repeating the above procedure, the unloading operation can be performed quickly and reliably.

In the procedure for detecting the position of the container group, two diagonal corners of the container group are detected prior to the gripping operation of the container 3, but they are positioned at the diagonal of the container group. If the XY plane coordinates are detected at the four corners and also at the intermediate positions of these corners, it is needless to say that more accurate information can be given to the control device and the malfunction of the clamp mechanism 9 can be reduced. .

In the above procedure, the next container gripping point is calculated based on the container dimensions based on the coordinates of the two diagonal corners of the container group. The error due to the gap at the time is not taken into account, and therefore, there is a possibility that the container 3 may not be grasped.

Therefore, when the camera 10 is to be moved to another imaging point other than the above, the track 2 must be set in advance.
The camera 10 is roughly moved to the three corners of the container group on the loading platform based on the XY plane coordinate data as described above, and then the space surrounded by the corners of the four containers 3 located at these three corners, respectively. Each part is detected, and the position of the container group is detected as described above. Then, based on the XY plane coordinates of these three corners, another imaging point is calculated based on the following principle.

That is, according to the above-described procedure, as shown in FIG. 7, the four corners A, B, and E of the container group are roughly moved after the camera 10 is roughly moved. XY plane coordinates P of the space part enclosed by the corners of
a, Pb, and Pe are obtained, and, for example, C, D, and
The XY plane coordinates Pc, Pd, and Pf of F are obtained as follows.

[0035]

Pc = (Pa + Pe) / 2 Pd = Pc + (Pb-Pa) Pf = Pe + (Pb-Pa)

As described above, the XY plane coordinates of the three corners of the container group are detected, and based on the coordinates, other plural imaging points are calculated.
If accurate position information is obtained by imaging at, the actual loading information of the container 3 can be obtained, so that the error is extremely small, and the unloading operation of the container 3 can be performed more reliably. .

Further, in any of the above-mentioned procedures, a non-contact type, for example, an ultrasonic distance sensor is provided near the camera 10, and the ultrasonic distance sensor is obtained by the four distances obtained as described above. By moving radially around the space surrounded by the corners of the containers 3, the heights of the four containers 3 up to the respective corners can be detected, and the height difference between the adjacent containers 3 allows the container group to be detected. The inclination can also be detected, and the loading information of the container group can be more accurately obtained. Also, by doing this,
The limit switch S1 in the above configuration can be omitted.

That is, of the four containers 3 located at one corner of the container group, three containers 3 are located at positions stacked in four levels in the height direction, and the remaining one is positioned in the height direction. When the three containers are in the stacked positions, the four containers 3 are imaged in the same state in plan view with the camera 10 whether they are at the same height position or not. Therefore, by adding height information to such information, the entire container group recognized by the control device can be three-dimensionally recognized, and the height change characteristics when the truck 2 is unloaded can be recognized by the height information. Can be converted into a database, and various information can be referred to from this database when a truck 2 having the same characteristics is stored in the future.

As described above, according to the method for detecting the container mounting state of the cargo handling device of the present invention, the information on the accurate position, height, and inclination of the container 3 loaded on the loading platform of the truck 2 is detected. Each time the container 3 is unloaded, even if the loading platform of the truck 2 and the uppermost layer of the container group rise or change in inclination, and the amount of the change is different for each vehicle type or individual truck 2, the automatic cargo handling is accurately performed. Each part of the equipment 1 can be controlled, so that the unloading operation of the container 3 can be performed quickly and efficiently.

In the above embodiment, the procedure for unloading the container 3 has been described. However, in order to load the container 3 onto the truck 2, the automatic cargo handling equipment 1 performs the reverse operation. In the method of the present invention, the plane position state of the loading platform is recognized based on the XY plane coordinates stored in advance from the planar coordinates of the empty truck 2 on the loading platform, and the operator determines the placement position of the container 3. Then, based on this information, the layers are stacked one by one based on this information. At the time of stacking, the camera 10 detects the center position surrounded by the four containers 3 in the preceding stage and targets the four containers 3 at a time. To load. As described above, by employing the method of the present invention also in the loading operation, the operation can be performed as quickly and reliably as above.

[0041]

As described above, according to the container loading state detecting method of the cargo handling apparatus of the present invention, the camera group images the container group on the truck bed, and the image data and the XY plane coordinates stored in advance. The actual position of the container group is detected with reference to the above, the inclination and the height of the actual container group are detected by the height detecting means, and each part of the cargo handling device is controlled based on the information. Therefore, the cargo handling operation can be performed accurately and quickly, and the height and inclination of the loading platform and the container group that change with the cargo handling operation can be coped with, thereby reducing malfunction.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of an automatic cargo handling equipment to which a method for detecting a container placement state of a cargo handling device according to the present invention is applied.

FIG. 2 is a side view showing the vicinity of the cargo handling device and the clamp mechanism in the automatic cargo handling equipment to which the container loading state detecting method of the cargo handling device according to the present invention is applied.

FIG. 3 is an enlarged view of a main part showing a side surface of a clamp mechanism in the automatic cargo handling equipment to which the container loading state detecting method of the cargo handling device of the present invention is applied.

FIG. 4 is an enlarged view of a main part of a clamp mechanism in the automatic cargo handling equipment to which the method for detecting a container placement state of a cargo handling device according to the present invention is applied.

5 (a) to 5 (d) are diagrams showing the detection pattern shapes of the corners of the container in the method for detecting the container placement state of the cargo handling device of the present invention.

FIGS. 6A to 6D are diagrams for explaining the principle of detecting the center position of a space surrounded by four containers in the container loading state detection method of the cargo handling device according to the present invention. .

FIG. 7 is a diagram showing another imaging point in the method for detecting a container placement state of a cargo handling device of the present invention.

[Explanation of symbols]

 Reference Signs List 1 automatic cargo handling equipment 3 container 4 cargo handling equipment 10 camera

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Maki Maekawa 5-28 Nishikujo, Konohana-ku, Osaka-shi, Osaka Inside Hitachi Zosen Corporation (72) Inventor Kiyoshi Okita 5-chome, Nishikujo, Konohana-ku, Osaka-shi, Osaka No. 28 of Hitachi Zosen Corporation (72) Inventor Tsunehito Mori 5-28 Nishikujo, Konohana-ku, Osaka City, Osaka Prefecture Inside of Hitachi Zosen Corporation

Claims (3)

[Claims] 1. An XY location where a truck enters and leaves
It has as plane coordinate data, and when a truck enters the XY plane coordinates, based on the XY plane coordinates,
The camera provided on the cargo handling device that travels and traverses is mounted on at least two diagonals of the upper surface of the entire container group on the truck bed.
After coarsely moving to a corner and detecting a space portion surrounded by four container corners from the image taken by the camera at each of these two diagonal corners, the center coordinates of the space portion are determined based on the detection result. Are calculated, and the center coordinates and the X-
A container loading state detection method for a cargo handling device, wherein the position of the entire container group on a truck bed is detected by comparing with a Y-plane coordinate. 2. A camera is coarsely moved to three corners on the entire upper surface of a group of containers on a truck bed based on XY plane coordinate data. At each of these three corners, four containers are selected from an image taken by the camera. After detecting each of the space portions surrounded by the corners, the coordinates of each of the space portions are obtained based on the detection result, and when the camera is moved to an imaging point other than the three corners, the three corners are used. 2. The container mounting state detecting method according to claim 1, wherein the method is performed based on the X-Y coordinates. 3. A camera is coarsely moved to at least two diagonal corners of the entire upper surface of the container group on the truck bed based on XY plane coordinate data, and images are taken by the camera at each of the two diagonal corners. After detecting a space portion surrounded by the corners of the four containers from the image, calculating coordinates of each space portion based on the detection result, four detection means provided in the cargo handling device that travels and traverses are provided. 3. The container is moved radially from the center of a space surrounded by the corners of the container, and the heights up to the corners of the container are respectively detected to detect the height and inclination of the container group. The container mounting state detection method of the cargo handling device described in the above.