JP3500053B2 - Container loading state detection method for cargo handling equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, when unloading a container loaded with fruits and vegetables loaded on a truck bed in a vegetable market, the plane position of a group of containers and the like. The present invention relates to a container loading state detection method for a cargo handling device that can accurately control the cargo handling device by detecting a height. 2. Description of the Related Art Conventionally, loading and unloading operations for unloading containers from trucks are performed manually. In addition, in order to improve the efficiency of unloading work by hand, the use of a cargo handling device has been studied. [0003] In a truck bed having a plurality of stacked containers, the truck bed and the uppermost layer of the container rise or change in inclination every time the container is unloaded. Moreover, 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 group of containers on the truck bed, there is a possibility that a malfunction may occur such as failure to grasp the container or dropping the container at an unrelated part. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and a container loading state detecting method of a cargo handling device capable of accurately controlling by detecting a 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 four container corners located at least at two diagonal corners of the entire upper surface of the container group, and detects the space portion. , The center coordinates are compared with the X-Y plane coordinates to detect the plane position of the entire container group on the truck bed, and then the image is surrounded by four container corners at the center of the imaging area. After matching the spatial portions, the number of pixels at the corners of the four containers in the predetermined range is detected, and the distance to the corners of the four containers is determined from the detection result to determine the height of the container group. From the detection result That is, the container placement state is detected. By doing so, it is possible to detect an accurate container placement state by detecting the plane position and the height position of the container group. According to the present invention, a place where a truck enters and leaves a vehicle is previously stored as XY plane coordinate data, and when a truck arrives within the XY plane coordinates, the XY plane is stored. On the basis of the plane coordinates, a camera provided in the traveling and traversing cargo handling device is roughly moved to at least two diagonal corners of the entire upper surface of the container group on the truck bed, and a camera is provided at each of these two diagonal corners. After detecting a space portion surrounded by the corners of the four containers from the captured image, the center coordinates of the space portion are determined based on the detection result, and these center coordinates are compared with the XY plane coordinates. To detect the plane position of the entire group of containers on the truck bed, and further align the space surrounded by the corners of the four containers imaged by the camera with the center of the imaging area, and adjust the corners of the four containers in a predetermined range. Pixel at After detecting the number, the distance to the corner of the four containers is determined based on the detection result, the height of the container on the truck bed is detected, and the container mounting state is determined from the detected height and the plane position. Is detected. 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 the 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 the clamp mechanism in the automatic cargo handling equipment. FIG. 4 is a plan view of a main part of the clamp mechanism in the automatic cargo handling equipment. 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 device 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 principle of detecting a pixel at a corner of a container. FIG. 8 shows the relationship between the height of the container group and the number of pixels. [0008] The container loading state detecting method of the cargo handling apparatus of the present invention is carried out by the automatic cargo handling equipment 1 shown in the figure. The automatic cargo handling equipment 1 loads or unloads the container 3 from the loading platform of the truck 2 of a light four-wheeled vehicle equipped with pneumatic tires, for example, and loads a pallet 1A on which the container 3 unloaded from the truck 2 is 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 pillars 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 which moves up and down from the transverse carriage 8. When driving the traveling cart 7, the traversing cart 8, and the clamp mechanism 9, each drive unit is controlled in accordance with an output from a control device (not shown), and each of them is configured to perform 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.
The following configuration is used to unload the pallet 1A or to load four containers 3 from the pallet 1A on the loading platform of the truck 2 in a lump. Reference numeral 11 denotes an elevating mechanism, for example, a winch, which is disposed on the traversing carriage 8, and the elevating base 12 is held in a suspended manner 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, a pantograph mechanism 13 is employed. In the configuration of this 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 elevating base 12 via a horizontal rotary mechanism. As the horizontal rotation mechanism of the rotary base 14, in this embodiment, a pivot 15 is pivotally supported by the elevating base 12 so as to be rotatable, 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 can be horizontally rotated 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 via the corresponding 8. The clamp unit 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 opposite corners of the container 3 from the inside with an extrusion fitting 19d attached to the rod end thereof in a projecting manner. Can be The clamping air cylinder 19c is disposed 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, a clamp switch 19 includes a limit switch S1 for stopping the rod end of the air cylinder 17 from projecting when the edge of the hand base 19a comes into contact with the container 3, and an arm base end of the clamp claw 19e. A limit switch S2 is provided for driving the winch 11 and raising the elevating base 12 when the parts come into contact with each other. 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 which protrudes in the running direction from a center position in the traversing direction of a traversing base 8a which holds the members of the traversing car 8, and is provided with a holding member 10a. 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, the position and height of the container 3 must be accurately detected. By providing the data to a 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 performing a container unloading operation.
Will be described. First, automatic cargo handling equipment 1
As shown in FIG. 1, a storage port 1a is provided at a position where the truck 2 is stored, and plane data of the storage port 1a is fixedly stored in a storage device (not shown) in advance in XY.
It is stored as plane coordinate data. Here, for example, the truck 2 is the storage port 1
a when the truck 2 enters the storage port a slightly obliquely, a shift occurs with respect to the XY plane coordinates. However, when the truck 2 enters the storage port 1a, the container group 4 placed on the loading platform must Assuming that the XY plane coordinates of each of the corners are respectively within the 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 this 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 entered into the 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 pattern shapes, that is, for example, the shapes shown in FIG. 5A are sequentially rotated by 90 °, 180 °, and 270 ° to form four patterns on the captured image. By detecting, the corners of the container 3 are detected one after another. Here, the pixels in the imaging regions shown in each of (a) to (d) in FIG. 5 are shown coarser than they actually are in order to show the principle. 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.
Detect where it is located on 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 of the predetermined range as described above, the center of the space part 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 X and Y, the position in the XY plane coordinates can be detected. If the above procedure is performed on at least two diagonal corners of the upper surface of the entire container group on the truck bed, the storage state of the truck 2 with respect to the storage port 1a can be recognized. On the other hand, in the method of the present invention, the height detection is performed after the camera 10 detects the planar position. This height detection is performed by the four containers 3 located at one corner of the container group obtained by the above-described container group plane detection.
The spatial portion surrounded by is aligned with the center of the imaging region, and how many pixels the adjacent corners of the four containers 3 are formed in a predetermined range of the imaging region is detected. Here, when the distance from the camera 10 to the container 3 in the uppermost layer is close, that is, the container group is located at a high position as shown in FIG. The adjacent corners of the containers 3 are imaged. On the contrary, when the container 3 of the uppermost layer is far from the camera 10, that is, in a position where the height of the container group is low, as shown in FIG. Three adjacent corners are imaged. Here, the number of pixels on one side excluding the bent portion of the corner of the container 3, for example, the number of pixels imaged in each
Detect all edges. Note that although FIG. 7 shows the pixels more finely than FIG. 5, since FIGS. 5 and 7 basically show only the pixels schematically, FIGS.
The consistency of the number of pixels is not limited. Then, the distance to the camera 10 corresponding to the number of pixels on each side is determined from the number of pixels imaged in each range, and thereafter, the distance from the standby position at a predetermined height of the camera 10 is determined as described above. By subtracting the distance to the camera 10, the height of the container group can be detected. In addition, 1
The relationship between the number of pixels on the side and the height of the container group is shown in FIG. The height of the space surrounded by the four containers 3 can be detected by calculating the average of the heights of the four adjacent containers 3 to each side of the corner. After the XY plane coordinates and the height position of the container group are detected in this way, the clamp mechanism 9 is finely adjusted in the XY directions based on the state information of the container group, and the detected height is detected. The winch 11 is driven to lower the elevating base 12 at a high speed to a position slightly before the position, and thereafter the winch 11 is stopped. Then, the rod of the air cylinder 17 is protruded until all the limit switches S1 corresponding to the four containers 3 operate, and after the limit switches S1 corresponding to the four containers 3 operate, the positioning air cylinder 19b and The air cylinder 19c for clamping is driven to grip the container 3. Then, the clamp air cylinder 19c is driven to drive the clamp pawl 19.
When the e is opened, the arm base end 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 12 is raised, and thereafter, the loading device 4 is mounted on the pallet 1A. Is moved, and the container 3 is placed here. The reason for driving the air cylinder 17 during the above operation is as follows. In other words, although the exact height is grasped by the height detection, if the elevating base 12 is lowered to that height at a high speed, there is a possibility that interference or collision may occur depending on the inclination of the container group. When the lowering of the elevating base 12 is stopped slightly before, and when the entire container group is inclined, for example, at the edge of the container 3 located at the inclined uppermost position among the four containers 3 grasped at a time. When the limit switch S1 is activated, the container 3 located at the lowermost position is inclined.
The reason for this is that the extrusion fitting 19d and the clamp claw 19e are not correctly positioned with respect to the container 3 and may fail to grasp the container 3 located at the lowermost position. Therefore, in order to securely grasp the four containers 3, the rod of the air cylinder 17 is protruded until the four limit switches S1 are operated. In this way, the hand base 19 is already placed on the upper edge of the container 3.
When a is in contact, the wire rope 18 bends,
Otherwise, the hand base 19a contacts the upper edge of the container 3 for the first time by projecting the rod of the air cylinder 17, and the container group is inclined with respect to the four containers 3 grasped at a time. Also extrusion fitting 19
d and the clamp claws 19e can be correctly positioned. 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. As described above, according to the container loading state detecting method of the cargo handling apparatus of the present invention, the information on the accurate plane position and height 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 top layer of the container group are raised or the inclination is changed, 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 container 3
Can be quickly and efficiently performed. 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, the layers are stacked one by one based on this information, and the X at the center position surrounded by the four containers 3 at the previous stage is
-Detect the Y-plane coordinates and height and load four containers 3 at a time with this as the target. By employing the method of the present invention also in the loading operation as described above, the operation can be performed as quickly and reliably as above. As described above, according to the container loading state detecting method of the cargo handling apparatus of the present invention, the camera group captures an image of the container group on the truck bed, and the captured image data and the X- The actual plane position of the container group is detected with reference to the Y-plane coordinates, and the actual height of the container group is obtained by detecting the number of pixels in the image data captured by the camera. Since the loading state is detected, each part of the cargo handling device can be accurately controlled based on this information, and the cargo handling work can be performed quickly, and the loading platform and the container group that change with the cargo handling work can be controlled. It can respond to height, inclination, etc., and can reduce 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 placement 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 container loading state detecting method of the 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 container loading state detection method 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 apparatus according to the present invention. . FIGS. 7 (a) and 7 (b) are diagrams for explaining the principle of height detection in the container loading state detection method of the cargo handling device according to the present invention. It is a figure which shows the corner part which does. FIG. 8 is a diagram showing the relationship between the number of pixels and the height in the method of detecting a container placement state of a cargo handling device according to the present invention. [Description of Signs] 1 Automatic cargo handling equipment 3 Container 4 Cargo handling equipment 10 Camera

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-40567 (JP, A) JP-A-4-244391 (JP, A) JP-A-3-234491 (JP, A) JP-A-2- 215621 (JP, A) JP 50-52777 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65G 67/02 B65G 63/00 B65G 57/00

Claims (1)

(57) [Claims] [Claim 1] The location where the truck enters and leaves the vehicle is determined in advance by XY.
It has as plane coordinate data, and when a truck arrives in 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 surrounded by the corners of four containers from the image taken by the camera at each of the two diagonal corners, the center coordinates of the space are determined based on the detection result. Are calculated, and the center coordinates and the X-
The plane position of the entire container group on the truck bed is detected by comparing the coordinates with the Y plane coordinates, and the space defined by the corners of the four containers imaged by the camera is aligned with the center of the imaging area, and After detecting the number of pixels at the corners of the four containers in the range, the distance to the corners of the four containers is determined based on the detection result, and the height of the container on the truck bed is detected. A container mounting state detection method for a cargo handling device, wherein the container mounting state is detected from the height and the plane position.