Handling system and method thereof

Abstract

To provide a handling system capable of coping with various containers.SOLUTION: A camera images an uppermost pallet PT which has been washed and conveyed; an edge PTX in an X-axis direction and an edge PTY in a Y-axis direction of the imaged uppermost pallet PT are detected; an intersection position KT between the detected edge PTX in the X-axis direction of the uppermost pallet PT and the detected edge PTY in the Y-axis direction of the pallet are confirmed; upon confirming the intersection position KT, a difference between the intersection position KT and a predetermined reference position O is calculated; and a position of the uppermost pallet PT is corrected on the basis of the difference.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a handling system and a method thereof. [Background technology]

[0002] In recent years, durable plastic pallets have become commonplace for cargo handling, replacing the traditional wooden ones. Since such plastic pallets are used repeatedly, they are usually collected and washed to remove any dirt that may have accumulated during use, and then reused.

[0003] Conventionally, systems that automatically perform this pallet washing involve placing untreated pallets, which are brought in stacked on top of each other by a forklift or the like, on a transport line such as a chain conveyor, first separating them one by one with an unstacker and sending them forward in a horizontal position, then washing them with a washing liquid sprayed from a nozzle in a washing machine and rinsing them with rinsing water if necessary, followed by hot air drying, and then stacking the treated pallets on top of each other with a stacker for collection. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] "Pallet cleaning", [online], Aikawa Co., Ltd., [Retrieved August 23, 2023], Internet (http: / / aikawa-gr.jp / pallet / ) Summary of the Invention [Problem to be solved by the invention]

[0005] Recently, in the above-mentioned system, a method has been proposed in which when processed pallets are stacked vertically in multiple stages using a stacker, the processed pallets are stacked vertically in multiple stages using a robot.

[0006] However, the above-mentioned method requires that the shape of the pallet is recognized and then the processed pallets are stacked vertically in multiple layers using a robot hand, so if the shape of the pallet cannot be recognized, the processed pallets cannot be stacked vertically in multiple layers. In other words, the above-mentioned method has a problem in that it cannot handle various pallets.

[0007] In view of the above problems, an object of the present invention is to provide a handling system and method capable of handling various containers. [Means for solving the problem]

[0008] The above object of the present invention can be achieved by the following means. Note that the parentheses indicate reference symbols of the embodiments described below, but the present invention is not limited thereto.

[0009] The handling system according to claim 1 includes an imaging means (e.g., the camera 4 shown in FIG. 2) for imaging a container that has been cleaned and transported (e.g., the top pallet PT shown in FIG. 2); A detection means (e.g., CPU 50 shown in FIG. 1) for detecting an edge in the X-axis direction (e.g., edge PTX in the X-axis direction shown in FIG. 3) and an edge in the Y-axis direction (e.g., edge PTY in the Y-axis direction shown in FIG. 3) of the container imaged by the imaging means; A confirmation means (e.g., CPU 50 shown in FIG. 1) for confirming an intersection position (e.g., intersection position KT shown in FIG. 3) between an edge of the container in the X-axis direction detected by the detection means and an edge of the container in the Y-axis direction; a calculation means (e.g., the CPU 50 shown in FIG. 1) for calculating a difference between the intersection position confirmed by the confirmation means and a predetermined reference position (e.g., reference position O shown in FIG. 3); The present invention is characterized by comprising a control means (e.g., robot controller 7 shown in FIG. 1) that controls a robot hand (e.g., robot hand 22 shown in FIG. 2) so as to correct the position of the container based on the difference calculated by the calculation means.

[0010] The handling system of claim 2 is the handling system of claim 1, wherein the detection means (e.g., CPU 50 shown in FIG. 1) detects the edge in the X-axis direction (e.g., edge PTX in the X-axis direction shown in FIG. 3) and the edge in the Y-axis direction (e.g., edge PTY in the Y-axis direction shown in FIG. 3) of the container (e.g., the top pallet PT shown in FIG. 3) by connecting multiple edge detection points (e.g., edge detection point T shown in FIG. 4) of the container imaged by the imaging means (e.g., camera 4 shown in FIG. 2) to generate a single line (e.g., single line XL shown in FIG. 4), thereby detecting the edges in the X-axis direction and the Y-axis direction of the container, and in this case, the edge detection points that fall outside a predetermined threshold value (e.g., threshold line KLa shown in FIG. 4) are ignored to generate the single line.

[0011] The handling system of claim 3 is the handling system of claim 1 or 2, wherein when the detection means (e.g., CPU 50 shown in FIG. 1) detects the edge in the X-axis direction (e.g., edge PTX in the X-axis direction shown in FIG. 5(a)) and the edge in the Y-axis direction (e.g., edge PTY in the Y-axis direction shown in FIG. 5(a)) of the container (e.g., the top pallet PT shown in FIG. 5(a)), if the edge detection points (e.g., edge detection point T shown in FIG. 5(b)) of the container imaged by the imaging means (e.g., camera 4 shown in FIG. 2) are connected to generate a single line (e.g., single line XL shown in FIG. 5(b)) and the single line is further away from a predetermined reference line (e.g., edge reference line XO in the X-axis direction and edge reference line YO in the Y-axis direction shown in FIG. 5(a)) than a predetermined position, the imaging means changes the position at which the container is imaged and re-images the container, and the detection means detects the edge in the X-axis direction and the edge in the Y-axis direction of the container again.

[0012] The handling method according to claim 4 is a handling method executed by a predetermined device (for example, the information processing device 5 shown in FIG. 1), a step of detecting an edge in the X-axis direction of a container (e.g., the top pallet PT shown in FIG. 2) in the X-axis direction (e.g., the edge PTX in the X-axis direction shown in FIG. 3) and an edge in the Y-axis direction of the container (e.g., the edge PTY in the Y-axis direction shown in FIG. 3) in the Y-axis direction (e.g., the edge PTY in the Y-axis direction shown in FIG. 3) that has been washed and transported (e.g., step S2 shown in FIG. 7); A step of confirming an intersection position between the edge of the container in the X-axis direction and the edge of the container in the Y-axis direction (for example, the intersection position KT shown in FIG. 3) (for example, step S3 shown in FIG. 7); A step of calculating a difference between the confirmed intersection position and a predetermined reference position (for example, reference position O shown in FIG. 3) (for example, step S4 shown in FIG. 7); The method is characterized by including a step of controlling a robot hand (e.g., robot hand 22 shown in FIG. 2) so as to correct the position of the container based on the calculated difference (e.g., steps S5 and S6 shown in FIG. 7). Effect of the Invention

[0013] Next, the effects of the present invention will be described with reference to the drawings. Note that the reference symbols in the parentheses are those of the embodiments described below, but the present invention is not limited thereto.

[0014] According to the inventions of claims 1 and 3, since the determination is made not by the shape of the container (for example, the top pallet PT shown in Fig. 2) but by the edge in the X-axis direction (for example, the edge PTX in the X-axis direction shown in Fig. 3) and the edge in the Y-axis direction (for example, the edge PTY in the Y-axis direction shown in Fig. 3), there is no need to specify the shape. Therefore, any type of container can be handled, for example, a mesh pallet, a pallet with a large corner radius, a container container, etc.

[0015] Therefore, the present invention can be adapted to various containers.

[0016] According to the invention of claim 2, even if an edge in the X-axis direction (e.g., edge PTX in the X-axis direction shown in FIG. 3) and / or an edge in the Y-axis direction (e.g., edge PTY in the Y-axis direction shown in FIG. 3) has a chip or a dent PTb as shown in FIG. 4, the edge in the X-axis direction (e.g., edge PTX in the X-axis direction shown in FIG. 3) and the edge in the Y-axis direction (e.g., edge PTY in the Y-axis direction shown in FIG. 3) can be detected without erroneous detection.

[0017] According to the invention of claim 3, it is possible to accommodate even if the position of a container (e.g., the top pallet PT shown in Figure 5(a)) is away from a predetermined reference line (e.g., the edge reference line XO in the X-axis direction and the edge reference line YO in the Y-axis direction shown in Figure 5(a)) by a predetermined value or more. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a simplified block diagram showing an embodiment of a handling system according to the present invention. [Diagram 2] 13 is a plan view showing a state in which the robot hand according to the embodiment is about to stack the top pallet on the bottom pallet. FIG. [Diagram 3] FIG. 13 is an explanatory diagram illustrating a method for correcting misalignment of the top pallet relative to the bottom pallet. [Figure 4] FIG. 13 is an explanatory diagram illustrating a method for detecting an edge in the X-axis direction of the top pallet. [Diagram 5] FIG. 1A illustrates a case where the position of the top pallet is significantly misaligned relative to the bottom pallet, FIG. 1B illustrates a method for detecting the edge of the dashed line A1 portion shown in FIG. 1A, FIG. 1C illustrates a case where the imaging range shown in FIG. 1A is shifted, and FIG. 1D illustrates a method for detecting the edge of the dashed line A2 portion shown in FIG. 1C. [Figure 6] FIG. 13 is an explanatory diagram illustrating a case where the top pallet is inclined relative to the bottom pallet. [Figure 7]FIG. 4 is a flowchart illustrating an example of use of the handling system according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of a handling system according to the present invention will be described in detail with reference to the drawings. In the following description, when directions such as up, down, left, and right are indicated, they refer to up, down, left, and right when viewed from the front of the figure.

[0020] <Outline of the handling system> The handling system 1 shown in Fig. 1 is capable of correcting the position of a treated pallet P that has been cleaned and dried and is transported by a conveyor C from the direction of arrow Y1 shown in Fig. 2, when the treated pallet P is stacked vertically in multiple stages in a stacker 3 (see Fig. 2) using a robot 2. Specifically, as shown in Fig. 1, the handling system 1 is made up of the robot 2, a camera 4, an information processing device 5, a PLC 6, and a robot controller 7. Each component will be described in detail below.

[0021] <Robot description> As shown in FIG. 1, the robot 2 is, for example, composed of a six-axis robot arm and includes a base 20 fixed to an installation surface such as a floor, a robot arm section 21 whose base end is rotatably connected to the base 20, and a robot hand 22 attached to the tip of the robot arm section 21 and capable of grasping a pallet P by clamping it.

[0022] As shown in Fig. 2, the robot hand 22 is composed of a horizontally long rectangular main body 22a, a left clamping piece 22b that is concave in plan view and provided so as to be freely stretched on the left side surface 22a1 side of the main body 22a, and a right clamping piece 22c that is concave in plan view and provided so as to be freely stretched on the right side surface 22a2 side of the main body 22a. Thus, the left clamping piece 22b and the right clamping piece 22c can clamp the pallet P shown in Figs. 1 and 2 by extending so as to be away from the main body 22a or contracting so as to be closer to the main body 22a. This allows the robot hand 22 to grip the pallet P.

[0023] As shown in FIG. 2, a camera 4 is attached and fixed to an upper surface 22a3 on the left side surface 22a1 side of the main body 22a of the robot hand 22 configured as described above.

[0024] <Camera description> The camera 4 is capable of capturing an image of the area around one of the four corners (see imaging range F shown in Figure 3) of a processed pallet P that has been cleaned and dried and is transported by the conveyor C shown in Figure 1, and outputting multiple edge detection points T shown in Figure 4.

[0025] <Description of information processing device> 1, the information processing device 5 includes a CPU 50, a RAM 51, a ROM 52, an auxiliary storage device 53, an input / output interface 54, a communication interface 55, a display device 56, a bus 57, an input controller 58, and an input device 59. The CPU 50 executes and controls each function of the information processing device 5, and the RAM 51 temporarily stores programs and data supplied from an external device or the like.

[0026] On the one hand, the ROM 52 stores programs and various parameters that do not require modification, and the auxiliary storage device 53 stores various information. And the input / output interface 54 performs data transmission and reception with external devices, and the communication interface 55 is a device for connecting to a network and performs data transmission and reception with external devices via the network.

[0027] On the other hand, the display device 56 displays the graphics drawn by the CPU 50, and the bus 57 is a system bus that connects the CPU 50, RAM 51, ROM 52, auxiliary storage device 53, input / output interface 54, communication interface 55, display device 56, and input controller 58. And the input controller 58 is a controller that controls the input signal from the input device 59, and the input device 59 is an external input device for receiving operation instructions from the user, such as a keyboard, mouse, etc. Note that the functions and processes of the information processing device 5 described later are realized by the CPU 50 reading out the programs stored in the ROM 52, etc. and executing these programs.

[0028] <PLC description> The PLC 6 passes commands between the information processing device 5 and the robot controller 7.

[0029] <Robot controller description> The robot controller 7 is a control device that houses a servo amplifier, a circuit board, etc., and is a device that comprehensively controls the movement of the robot 2. Also, the robot controller 7 can store and execute a program for controlling the robot 2 created in advance.

[0030] <Description of usage example of handling system> Next, with reference to the flowchart shown in FIG. 7, the usage example of the handling system 1 shown in this embodiment will be described.

[0031] First, when the bottommost pallet PB, which has been cleaned and dried as shown in Fig. 1, is transported by the conveyor C, the positioning of the bottommost pallet PB in the stacker 3 as shown in Fig. 2 is performed by an operator or a robot 2. Then, when the position is determined, an image of the periphery of the upper left corner PBa (see the imaging range F shown in Fig. 3) of the four corners of the bottommost pallet PB is captured by the camera 4 as shown in Fig. 2, and this captured image is stored in the auxiliary storage device 53 by the CPU 50 of the information processing device 5 as shown in Fig. 1 as the reference position O (see Fig. 3), the edge reference line XO in the X-axis direction (see Fig. 3), and the edge reference line YO in the Y-axis direction (see Fig. 3) (step S1).

[0032] Next, when the topmost pallet PT that has been cleaned and dried as shown in FIG. 2 is conveyed by the conveyor C (see FIG. 1), the robot controller 7 controls the robot 2. As a result, the topmost pallet PT is sandwiched between the left and right sandwiching pieces 22b and 22c of the robot hand 22, and stacked on the bottommost pallet PB arranged in the stacker 3. At this time, as shown in FIG. 2, the camera 4 captures an image of the upper left corner PTa of the topmost pallet PT among the four corners. To explain in more detail, the camera 4 captures an image of a corner portion of the topmost pallet PT located within the imaging range F shown in FIG. 3, and the captured image is output to the information processing device 5 shown in FIG. 1. The captured image includes a plurality of edge detection points T shown in FIG. 4.

[0033] Thus, in response to this, the CPU 50 of the information processing device 5 shown in Fig. 1 connects the multiple edge detection points T shown in Fig. 4 to generate a single straight line XL as shown in Fig. 4. This makes it possible to detect the edge PTX in the X-axis direction of the topmost pallet PT shown in Fig. 3. Similarly, it is also possible to detect the edge PTY in the Y-axis direction of the topmost pallet PT shown in Fig. 3.

[0034] Incidentally, when detecting the edge PTX in the X-axis direction and the edge PTY in the Y-axis direction of the top pallet PT shown in Fig. 3, if there is a chip or a recessed portion PTb in the edge PTX in the X-axis direction as shown in Fig. 4, the line XL is detected as being bent at the chip or recessed portion PTb, which may cause a false detection such as the line ending at this portion. Therefore, when generating one line XL, the CPU 50 shown in Fig. 1 generates a reference model line KL of the point group average value, and ignores edge detection points T that deviate from a threshold line KLa that is preset for the reference model line KL, to generate one line XL as shown in Fig. 4. That is, as shown in Fig. 4, the portion where the straight line is interrupted is corrected as shown by a two-dot chain line to generate one line XL. Thus, by doing this, even if there is a chip or a dent PTb in the edge PTX in the X-axis direction and the edge PTY in the Y-axis direction of the top pallet PT shown in Figure 3, it is possible to detect the edge PTX in the X-axis direction and the edge PTY in the Y-axis direction of the top pallet PT shown in Figure 3 without erroneous detection.

[0035] However, as shown in FIG. 5, if the topmost pallet PT is significantly misaligned with the bottommost pallet PB, the corner of the topmost pallet PT located within the imaging range F of the camera 4 shown in FIG. 5(a) will be small. In this case, as shown in FIG. 5(b), the number of edge detection points T located in the X-axis direction will be small. In this case, when generating one line XL, the CPU 50 of the information processing device 5 shown in FIG. 1 may mistakenly determine that the edge detection point T located in the Y-axis direction is the edge detection point T located in the X-axis direction, and generate one line XL. In this case, the edge PTX in the X-axis direction should not be inclined as shown in FIG. 5(a), but is detected as inclined as shown in FIG. 5(b). Therefore, in this embodiment, after generating one line XL, the CPU 50 of the information processing device 5 shown in FIG. 1 reads out the edge reference line XO in the X-axis direction shown in FIG. 5(a) stored in the auxiliary storage device 53, and calculates the distance DX between the edge reference line XO in the X-axis direction and the one line XL. If the distance DX is equal to or greater than a predetermined value, the CPU 50 shown in FIG. 1 instructs the camera 4 to change the position of the imaging range F. In response to this, the camera 4 moves the imaging range F in the upper right direction as shown in FIG. 5(c). As a result, as shown in FIG. 5(d), the number of edge detection points T located in the X-axis direction in the image captured again increases. In this way, when generating one line XL again, the CPU 50 of the information processing device 5 shown in FIG. 1 is less likely to erroneously determine that the edge detection point T located in the Y-axis direction is the edge detection point T located in the X-axis direction, and generate one line XL. When generating one line XL again, the CPU 50 of the information processing device 5 shown in FIG. 1 reads out the edge reference line XO in the X-axis direction shown in FIG. 5(a) stored in the auxiliary storage device 53, and calculates the distance DX between the edge reference line XO in the X-axis direction and one line XL, as described above. Then, it is determined whether or not this distance DX is equal to or greater than a predetermined value, and if there is no problem, this is detected as an edge PTX in the X-axis direction.

[0036] Therefore, by doing this, it is possible to deal with the situation even if the topmost pallet PT is significantly misaligned with the bottommost pallet PB. Although a detailed explanation is omitted, the same is true when detecting an edge PTY located in the Y-axis direction, and the edge reference line YO in the Y-axis direction shown in Figure 5(a) stored in the auxiliary storage device 53 is read out and the distance DY is calculated.

[0037] Thus, after generating a single line XL, the CPU 50 of the information processing device 5 shown in FIG. 1 calculates the distance DX from the edge reference line XO in the X-axis direction and the distance DY from the edge reference line YO in the Y-axis direction. Therefore, even if the top pallet PT is tilted relative to the bottom pallet PB, as shown in FIG. 6, it is possible to detect the tilt (step S2).

[0038] Next, the CPU 50 of the information processing device 5 shown in FIG. 1 confirms the intersection position KT (see FIG. 3) of the edge PTX in the X-axis direction and the edge PTY in the Y-axis direction of the detected uppermost pallet PT (step S3).

[0039] Next, the CPU 50 of the information processing device 5 shown in FIG. 1 reads out the reference position O shown in FIG. 3 stored in the auxiliary storage device 53, and calculates the amount of deviation from the intersection position KT confirmed above (step S4).

[0040] Next, the CPU 50 of the information processing device 5 shown in FIG. 1 outputs the calculated amount of deviation as a correction value to the PLC 6 shown in FIG. 1, and the PLC 6 outputs the correction value to the robot controller 7. In response to this, the robot controller 7 controls the robot 2 based on the correction value (step S5). As a result, the robot 2 moves the intersection position KT (see FIG. 3) of the top pallet PT sandwiched between the left clamping piece 22b and the right clamping piece 22c of the robot hand 22 so that it is located at the reference position O shown in FIG. 3, and stacks the top pallet PT on the stacker 3 shown in FIG. 2. Note that, as shown in FIG. 6, if the top pallet PT is inclined with respect to the bottom pallet PB, the robot 2 stacks the top pallet PT on the stacker 3 shown in FIG. 2, taking the inclination into consideration.

[0041] Thus, by doing this, when using the robot 2 shown in FIG. 1 to stack pallets P in multiple layers in the stacker 3 shown in FIG. 2, as shown in FIG. 1, it is possible to stack the pallets P with minimal positional deviation.

[0042] Therefore, according to this embodiment, when pallets P are stacked vertically in multiple levels as shown in Fig. 1 in the stacker 3 shown in Fig. 2, the shape is determined not by the shape of the topmost pallet PT but by the edge PTX in the X-axis direction and the edge PTY in the Y-axis direction, so there is no need to specify the shape. Therefore, any type of pallet can be handled, for example, a mesh pallet or a pallet with a large corner R.

[0043] Therefore, according to this embodiment, it is possible to accommodate a variety of pallets.

[0044] <Description of Modifications> The shapes and the like shown in this embodiment are merely examples, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. For example, in this embodiment, the robot 2 composed of a robot arm with six axes is illustrated, but the present invention is not limited to this, and a four-axis robot or any other robot may be used.

[0045] In addition, in this embodiment, an example is shown in which the topmost pallet PT is clamped between the left clamping piece 22b and the right clamping piece 22c and the topmost pallet PT is grasped by the robot hand 22, but this is not limited to this, and any method such as suction can be used as long as the pallet P can be grasped.

[0046] Further, in the present embodiment, the pallet P has been described as an example, but the present invention is not limited to this and can also be applied to a container vessel. [Explanation of symbols]

[0047] 1 Handling System 2. Robot 22 Robot Hand 4. Camera (imaging means) 5. Information processing device (specified device) 50 CPU (detection means, confirmation means, calculation means) 7 Robot controller (control means) P Palette PT Top pallet (container) PTX Edge in X-axis direction PTY Y-axis edge O Reference position XO Reference line in the X-axis direction (reference line) YO Reference line in the Y-axis direction (reference line) KT intersection position T Edge detection point XL 1 line KLa threshold line (predetermined threshold)

Claims

1. an imaging means for imaging the container that has been washed and transported; a detection means for detecting an edge in an X-axis direction and an edge in a Y-axis direction of the container imaged by the imaging means; a confirmation means for confirming an intersection position between an edge of the container in the X-axis direction detected by the detection means and an edge of the container in the Y-axis direction; a calculation means for calculating a difference between the intersection position and a predetermined reference position when the intersection position is confirmed by the confirmation means; and a control means for controlling the robot hand so as to correct the position of the container based on the difference calculated by the calculation means.

2. The handling system described in claim 1, wherein the detection means detects the edges of the container in the X-axis direction and the Y-axis direction by connecting multiple edge detection points of the container imaged by the imaging means to generate a single line, and in this case, the edge detection points that fall outside a predetermined threshold value are ignored to generate the single line.

3. The handling system described in claim 1 or 2, wherein when the detection means detects the edges of the container in the X-axis direction and the Y-axis direction by connecting multiple edge detection points of the container imaged by the imaging means to generate a line, if the line is more than a predetermined position away from a predetermined reference line, the imaging means changes the position at which the container is imaged and re-images it, and the detection means redetects the edges of the container in the X-axis direction and the Y-axis direction.

4. A handling method performed by a predetermined device, comprising: detecting an edge in an X-axis direction of the container that has been washed and transported and an edge in a Y-axis direction of the container that has been washed and transported; confirming an intersection position between the detected edge of the container in the X-axis direction and the edge of the container in the Y-axis direction; Calculating a difference between the confirmed intersection position and a predetermined reference position; and controlling the robot hand so as to correct the position of the container based on the calculated difference.

Images