Holding device and method

Abstract

To improve transport capacity in a holding device and a holding method.SOLUTION: A holding device includes: an upper surface holding unit having a first suction surface capable of suctioning upper surfaces of articles; a determination unit which determines whether or not the upper surface holding unit can suction the articles and move up according to areas of the upper surfaces of the articles and arrangement of the articles; and a control unit which controls movement of the upper surface holding unit according to a determination result of the determination unit.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a gripping device and method for gripping an object. [Background technology]

[0002] There is known a conveying device such as a palletizing device that stacks articles on trays such as pallets. For example, Patent Document 1 describes a gripping device in the conveying device that sucks and grips the top surface of an article. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6793428 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, multiple items are stacked on a pallet. The gripping device picks up and transports the multiple items stacked on the pallet one by one. This increases the time it takes to transport the items using the gripping device, which results in poor workability.

[0005] The present disclosure is devised to solve the above-mentioned problems, and aims to provide a gripping device and method capable of improving conveying capacity. [Means for solving the problem]

[0006] In order to achieve the above-mentioned objective, the gripping device of the present disclosure comprises an upper surface gripping unit having a first adsorption surface capable of adsorbing to the upper surface of an object, a determination unit that determines whether the upper surface gripping unit can be adsorbed to multiple objects and lifted depending on the area of ​​the upper surfaces of the objects and the arrangement of the objects, and a control unit that controls the movement of the upper surface gripping unit depending on the determination result of the determination unit.

[0007] In addition, the gripping method disclosed herein includes a step of providing an upper surface gripping portion having a first suction surface capable of adsorbing to the upper surface of an object, and determining whether or not the upper surface gripping portion can be adsorbed to multiple objects and lifted depending on the area of ​​the upper surface of the objects and the arrangement of the objects, and a step of controlling the movement of the upper surface gripping portion when it is determined that the upper surface gripping portion can be adsorbed to multiple objects and lifted. Effect of the Invention

[0008] The gripping device and method disclosed herein can improve transport capabilities. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a gripping device according to the present embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a state in which the gripping device shown in FIG. 1 is flipped up by 90 degrees. [Diagram 3] FIG. 3 is a schematic diagram showing a 180° flip-up state of the gripping device shown in FIG. [Figure 4] FIG. 4 is a schematic block diagram of the gripping device shown in FIG. [Diagram 5] FIG. 5 is a flowchart illustrating a process flow of the control device. [Figure 6] FIG. 6 is a plan view for explaining a typical unloading operation by the gripping device. [Figure 7] FIG. 7 is a cross-sectional view taken along the line II-II shown in FIG. [Figure 8] FIG. 8 is a cross-sectional view showing the state after FIG. [Figure 9] FIG. 9 is a plan view for explaining a schematic result of a determination as to whether or not multiple objects can be picked up by the gripping device. [Figure 10] FIG. 10 is a plan view for explaining a schematic result of a determination as to whether or not multiple objects can be picked up by the gripping device. [Figure 11] FIG. 11 is a plan view for explaining a schematic result of a determination as to whether or not multiple objects can be picked up by the gripping device. [Figure 12]FIG. 12 is a plan view for explaining a schematic result of a determination as to whether or not multiple objects can be picked up by the gripping device. [Figure 13] FIG. 13 is a plan view for explaining a schematic result of a determination as to whether or not multiple objects can be picked up by the gripping device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments according to the present disclosure will be described in detail with reference to the drawings. Note that the present invention is not limited to these embodiments. In addition, the components in the following embodiments include those that are replaceable and easy for a person skilled in the art, those that are substantially the same, or those that are equivalent. Furthermore, the components in the following embodiments can be omitted, replaced, or modified in various ways without departing from the gist of the present disclosure. In the following embodiments, the components necessary for illustrating the embodiments will be described, and other components will be omitted, and the same components will be given the same reference numerals, and different components will be given different reference numerals.

[0011] [Embodiment] <Configuration of the gripping device> Fig. 1 is a schematic diagram of a gripping device according to this embodiment. Fig. 2 is a schematic diagram showing a 90° flip-up mode of the gripping device shown in Fig. 1. Fig. 3 is a schematic diagram showing a 180° flip-up mode of the gripping device shown in Fig. 1. Fig. 4 is a schematic block diagram of the gripping device shown in Fig. 1. The gripping device 1 shown in Figs. 1 to 4 is attached to a palletizing device as a conveying device, and is a device for stacking articles on a pallet, unloading articles from a pallet, or transferring articles from one pallet to another pallet in a facility where logistics is managed, such as a warehouse.

[0012] Here, the definition of a pallet by the Japan Pallet Association is "a surface on which cargo is placed in a single unit, and has a structure that allows loading, transporting, and storage all by hand or by a dedicated vehicle such as a forklift. It includes those with a superstructure." In this embodiment, a pallet refers to a container or platform on which the goods R are loaded. That is, the pallet here is not limited to a so-called flat platform, but also includes a cage cart and may be of any shape. The goods R are loaded on the pallet, for example, goods to be shipped. The goods R are also referred to as cardboard boxes in which goods are packed. The goods R have at least a flat top surface Ra, and in this embodiment, a rectangular or cubic cardboard box is assumed.

[0013] 1 to 3, the gripping device 1 includes a base 10, an upper gripping unit 20, a side gripping unit 30, a first arm 40, a second arm 50, and a flip-up mechanism 60. As shown in Fig. 4, the gripping device 1 further includes an imaging device 70, an input / output device 80, and a control device 90 that controls the operation of each part of the gripping device 1. In this embodiment, the gripping device 1 including the imaging device 70, the input / output device 80, and the control device 90 includes a mode in which the functions of each device are configured as part of the functions of a palletizing device to which the gripping device 1 is attached, or a conveying system to which the palletizing device is deployed.

[0014] In this embodiment, the article R is stacked on a pallet, and the upper side in the vertical direction is the top surface Ra, and the side in the horizontal direction perpendicular to the vertical direction is the side surface Rb. The direction perpendicular to the second opposing surface 30a opposing the side surface Rb of the article R when the side surface gripping unit 30 supports the side surface Rb is defined as the X-axis direction, the direction parallel to the rotation axis A of the flip-up mechanism 60 is defined as the Y-axis direction, and the direction perpendicular to the X-axis and Y-axis directions and perpendicular to the first opposing surface 20a opposing the top surface Ra when the top surface gripping unit 20 supports the top surface Ra of the article R is defined as the Z-axis direction. At least during the operation of the gripping device 1, the X-axis and Y-axis directions correspond to the horizontal direction, and the Z-axis direction corresponds to the vertical direction.

[0015] 1 to 3 is connected to the tip of the arm of the palletizing device to which the gripping device 1 is attached via a rotating shaft 12, a rotating mechanism 14, and a lifting mechanism 16. The rotating shaft 12 is fixed to the upper surface side of the base 10 so that its axis is parallel to the Z-axis direction. The base 10 and the rotating shaft 12 are supported rotatably in a rotational direction φ around the axis of the rotating shaft 12 with respect to the arm of the palletizing device.

[0016] The turning mechanism 14 shown in Fig. 4 turns the base 10 and the turning shaft 12 in a rotation direction φ. For example, if the palletizing device is a multi-joint robot, the turning of the turning shaft 12 by the turning mechanism 14 corresponds to the operation of the sixth axis of the multi-joint robot. The turning mechanism 14 is realized by a well-known mechanism such as a rotary actuator including a motor, a rack-and-pinion mechanism including an air cylinder, or a wire or link mechanism. The operation of the turning mechanism 14 is controlled by a control unit 96 of the control device 90.

[0017] The lifting mechanism 16 linearly moves the base 10 and the rotating shaft 12 in a vertical direction V parallel to the Z-axis direction. For example, if the palletizing device is a multi-joint robot, the linear movement of the rotating shaft 12 by the lifting mechanism 16 is achieved by the cooperative operation of multiple axes of the multi-joint robot. If the palletizing device is a Cartesian coordinate robot, the linear movement of the rotating shaft 12 by the lifting mechanism 16 corresponds to the operation of a vertical linear joint of the Cartesian coordinate robot. In this case, the lifting mechanism 16 is achieved by a well-known mechanism such as a linear actuator including a motor, an air cylinder, etc., or a rack and pinion mechanism. The operation of the lifting mechanism 16 is controlled by a control unit 96 of the control device 90.

[0018] The upper surface gripping part 20 is provided on the lower part of the base 10. The upper surface gripping part 20 has a first opposing surface 20a on its lower surface that faces the upper surface Ra of the article R. The upper surface gripping part 20 is fixed to the base 10 so that the first opposing surface 20a is perpendicular to the Z-axis direction. The upper surface gripping part 20 rises and falls and rotates in accordance with the rising and lowering movements and rotation movements of the base 10 and the rotating shaft part 12. The upper surface gripping part 20 has a first suction part 22 on the first opposing surface 20a that can suction the article R.

[0019] In the examples shown in Figs. 1 to 3, the first suction unit 22 is depicted as a single block shape, but may be, for example, a plurality of suction pads protruding downward from the first opposing surface 20a of the upper gripping unit 20. The first suction unit 22 has a first suction surface 22a at its lower end. When the first suction surface 22a is in contact with the upper surface Ra of the article R, the first suction unit 22 is attracted to the upper surface Ra of the article R by the operation of the first suction mechanism 24 shown in Fig. 4. The first suction mechanism 24 includes, for example, a vacuum generator connected to the first suction surface 22a via an air pipe (not shown) and sucking air from the first suction surface 22a. For example, when the first suction unit 22 is composed of a plurality of suction pads, each suction pad is connected to the first suction mechanism 24, which is a vacuum generator, via an air pipe. The operation of the first suction mechanism 24 is controlled by the control unit 96 of the control device 90.

[0020] The side gripping part 30 is provided on the side of the base 10 in the X-axis direction via the first arm 40, the second arm 50, and the flip-up mechanism 60. The side gripping part 30 has a second opposing surface 30a that faces the side surface Rb of the article R. The side gripping part 30 can move in the longitudinal direction of the first arm 40 relative to the base 10 by a first telescopic mechanism 44 described later. The side gripping part 30 can also move in the longitudinal direction of the second arm 50 relative to the base 10 by a second telescopic mechanism 54 described later. The side gripping part 30 can also rotate in a rotation direction θ around a rotation axis A of the flip-up mechanism 60 relative to the base 10 by the flip-up mechanism 60. The rotation axis A is a horizontal axis parallel to both the first suction surface 22a of the upper gripping part 20 and the second suction surface 32a of the side gripping part 30.

[0021] The side gripping unit 30 can move relative to the top gripping unit 20 in the XZ plane by the first telescopic mechanism 44, the second telescopic mechanism 54, and the flip-up mechanism 60. In other words, the first telescopic mechanism 44 and the second telescopic mechanism 54 are moving mechanisms that move the side gripping unit 30 relative to the top gripping unit 20. The side gripping unit 30 of this embodiment does not move relative to the top gripping unit 20 in the Y-axis direction, but may be configured to be relatively movable in the Y-axis direction. The side gripping unit 30 has a second suction unit 32 that can suction the article R on the second opposing surface 30a.

[0022] In the examples shown in Figs. 1 to 3, the second suction unit 32 is depicted as a single block shape, but may be, for example, a plurality of suction pads protruding from the second opposing surface 30a of the side gripping unit 30. The second suction unit 32 has a second suction surface 32a at an end opposite to the second opposing surface 30a. When the second suction surface 32a is in contact with the side surface Rb of the article R, the second suction unit 32 is caused to adhere to the side surface Rb of the article R by the operation of the second suction mechanism 34 shown in Fig. 4. The second suction mechanism 34 includes, for example, a vacuum generator connected to the second suction surface 32a via an air pipe (not shown) and sucking air from the second suction surface 32a. For example, when the second suction unit 32 is composed of a plurality of suction pads, each suction pad is connected to the second suction mechanism 34, which is a vacuum generator, via an air pipe. The operation of the second suction mechanism 34 is controlled by the control unit 96 of the control device 90.

[0023] In the state shown in FIG. 1 where the longitudinal direction of the first arm 40 is parallel to the X-axis direction and the longitudinal direction of the second arm 50 is parallel to the Z-axis direction, the second opposing surface 30a of the side gripping portion 30 faces the side surface Rb of the article R. In this case, the second suction surface 32a of the second suction portion 32 faces the side surface Rb of the article R. Also, in this case, the entire surface of the second suction surface 32a is located below the first suction surface 22a. In the state shown in FIG. 2 where the longitudinal direction of the first arm 40 is parallel to the Z-axis direction and the longitudinal direction of the second arm 50 is parallel to the X-axis direction, the second opposing surface 30a faces vertically downward. In this case, the second suction surface 32a of the second suction portion 32 faces vertically downward. Also, in this case, the second suction surface 32a is located above the first suction surface 22a by a distance B.

[0024] The first arm 40 is provided on the side of the base 10 in the X-axis direction via the second arm 50 and the flip-up mechanism 60. The first arm 40 has a first support 42 and a first telescopic mechanism 44. The first support 42 is located at one end side of the longitudinal direction of the first arm 40. The first support 42 is connected to the second arm 50. The first support 42 supports the first telescopic mechanism 44 and is connected to the side grip 30 via the first telescopic mechanism 44. In this embodiment, the first support 42 has a frame shape that houses and supports the first fixed part 44a of the first telescopic mechanism 44. The first telescopic mechanism 44 extends along the longitudinal direction of the first arm 40 and is telescopic in a first telescopic direction F1, which is the longitudinal direction of the first arm 40. In the state shown in FIG. 1 where the longitudinal direction of the first arm 40 is parallel to the X-axis direction and the longitudinal direction of the second arm 50 is parallel to the Z-axis direction, the first telescopic mechanism 44 is pre-extended and retracted to match the width dimension w of the article R so that the second suction surface 32a abuts against the side surface Rb of the article R.

[0025] In this embodiment, the first telescopic mechanism 44 includes a first fixed part 44a and a first movable part 44b. The first fixed part 44a is fixed to the first support part 42. The first fixed part 44a supports the first movable part 44b so that the first movable part 44b can move linearly in the first telescopic direction F1 within a predetermined range. The first movable part 44b can move in the first telescopic direction F1 relative to the first fixed part 44a. One end side of the first movable part 44b in the longitudinal direction is supported by the first fixed part 44a. The other end side of the first movable part 44b in the longitudinal direction is fixed to the side grip part 30. The first telescopic mechanism 44 is realized by a well-known mechanism such as a cylinder having a cylindrical first fixed part 44a and a rod-shaped first movable part 44b, an electric actuator, a wire, or a link mechanism.

[0026] The second arm 50 is provided on the side of the base 10 in the X-axis direction via the flip-up mechanism 60. The second arm 50 has a second support 52 and a second telescopic mechanism 54. The second support 52 is located at one end of the second arm 50 in the longitudinal direction. The second support 52 is connected to the flip-up mechanism 60. The second support 52 supports the second telescopic mechanism 54 and is connected to the first support 42 of the first arm 40 via the second telescopic mechanism 54. In this embodiment, the second support 52 has a frame shape that accommodates and supports the second fixed portion 54a of the second telescopic mechanism 54. The second telescopic mechanism 54 extends along the longitudinal direction of the second arm 50 and is telescopic in a second telescopic direction F2, which is the longitudinal direction of the second arm 50. In the embodiment shown in FIG. 1, where the longitudinal direction of the first arm 40 is parallel to the X-axis direction and the longitudinal direction of the second arm 50 is parallel to the Z-axis direction, the second extension mechanism 54 is pre-extended and retracted to match the height dimension h of the article R so that the second suction surface 32a abuts at a suitable height position on the side surface Rb of the article R.

[0027] In this embodiment, the second telescopic mechanism 54 includes a second fixed part 54a and a second movable part 54b. The second fixed part 54a is fixed to the second support part 52. The second fixed part 54a supports the second movable part 54b so that the second movable part 54b can move linearly in the second telescopic direction F2 within a predetermined range. The second movable part 54b can move in the second telescopic direction F2 relative to the second fixed part 54a. One end side of the second movable part 54b in the longitudinal direction is supported by the second fixed part 54a. The other end side of the second movable part 54b in the longitudinal direction is fixed to the first support part 42 of the first arm part 40. The second telescopic mechanism 54 is realized by a well-known mechanism such as a cylinder having a cylindrical second fixed part 54a and a rod-shaped second movable part 54b, an electric actuator, a wire, or a link mechanism.

[0028] The flip-up mechanism 60 can be switched between a first state (the state shown in FIG. 1) in which the side gripping portion 30 is positioned below the lower end of the upper gripping portion 20 (the first suction surface 22a of the first suction portion 22 in this embodiment) and a second state (the state shown in FIGS. 2 and 3) in which the side gripping portion 30 is positioned above the lower end of the upper gripping portion 20. The flip-up mechanism 60 is connected to the upper gripping portion 20 via the base 10. The flip-up mechanism 60 is also connected to the side gripping portion 30 via the first arm portion 40 and the second arm portion 50. The flip-up mechanism 60 of this embodiment is provided on the side of the base 10 in the X-axis direction. The flip-up mechanism 60 rotates the second arm portion 50, the first arm portion 40, and the side gripping portion 30 relative to the base 10 in a rotation direction θ around a rotation axis A parallel to the Y-axis direction.

[0029] In this embodiment, the flip-up mechanism 60 has a fixed part 62 and a rotating part 64. The fixed part 62 is fixed to the connecting part 10a of the base 10. That is, the fixed part 62 moves integrally with the base 10 and the upper grip part 20. The rotating part 64 is rotatable in a rotation direction θ around a rotation axis A relative to the fixed part 62. The rotating part 64 is fixed to the second support part 52 of the second arm part 50. The flip-up mechanism 60 is realized by a well-known mechanism such as a rotary actuator including a motor, a rack and pinion mechanism including an air cylinder, a wire or link mechanism, etc. The flip-up mechanism 60 has a lock mechanism (not shown) that can position the position of the rotation direction θ of the rotating part 64 relative to the fixed part 62. The lock mechanism is realized by a well-known mechanism such as an air lock using high-pressure air, a mechanical lock using a motor drive, or a solenoid lock using an electromagnetic solenoid.

[0030] The flip-up mechanism 60 allows the side gripping portion 30, the first arm portion 40, and the second arm portion 50 to rotate in a rotation direction θ around the rotation axis A between the 0° position shown in FIG. 1, the 90° position shown in FIG. 2, and the 180° position shown in FIG. 3. In addition, the side gripping portion 30, the first arm portion 40, and the second arm portion 50 can be positioned at any position between the 0° position shown in FIG. 1 and the 180° position shown in FIG. 3 by a locking mechanism (not shown). In the 0° position shown in FIG. 1, the first arm portion 40 is located lower than the second arm portion 50, and the second suction surface 32a of the side gripping portion 30 is located lower than the first suction surface 22a of the upper gripping portion 20 and faces the side surface Rb of the article R. In the 90° position shown in FIG. 2, the second suction surface 32a of the side gripping portion 30 faces vertically downward and is located above the first suction surface 22a of the upper gripping portion 20 by a distance B. At the 180° position shown in FIG. 3, the second suction surface 32a of the side gripping portion 30 faces the X-axis direction opposite to the base portion 10, and the first arm portion 40 is positioned above the second arm portion 50.

[0031] The imaging device 70 captures an image of a pallet on which the article R is to be loaded or unloaded, the article R loaded on the pallet, and the stacked arrangement of the articles R, and outputs image data capable of identifying the position and individual objects of the imaged object to the control device 90. The imaging device 70 is disposed in a position where the pallet and the articles R loaded on the pallet can be observed. At this time, the imaging device 70 captures an image of all (multiple) articles R loaded on the pallet, thereby capturing an image of the stacked arrangement of the multiple articles R, that is, the layout of the multiple articles R. The imaging device 70 may be attached to the gripping device 1, or may be disposed separately from the gripping device 1. The imaging device 70 includes one or more cameras.

[0032] The input / output device 80 includes an input device through which an operator inputs various pieces of information for operating the gripping device 1, and an output device for presenting various pieces of information to the operator. The input device is realized by, for example, a keyboard, a mouse, a physical switch, a button, a touch panel, or the like. The output device is realized by, for example, a display device including a liquid crystal display device, an organic EL (Electro Luminescence) display device, or the like, a light-emitting device including an LED (Light Emitting Diode), or a speaker, or the like. The input / output device 80 may be an information terminal capable of inputting and outputting various pieces of information.

[0033] The control device 90 is a computer that controls the gripping device 1. The control device 90 has a communication unit 92, a storage unit 94, a control unit 96, and a determination unit 97. The communication unit 92 is a module used by the control unit 96 to communicate with an external device such as the management device 100, and may include, for example, an antenna. In this embodiment, the communication method by the communication unit 92 is assumed to be wireless communication, but the communication method may be arbitrary. The storage unit 94 is a memory that stores the calculation contents and programs of the control unit 96, and various information acquired from the management device 100 via the communication unit 92, and includes, for example, at least one of a RAM (Random Access Memory), a main storage device such as a ROM (Read Only Memory), and an external storage device such as an HDD (Hard Disk Drive).

[0034] The control unit 96 is an arithmetic processing device, and includes an arithmetic circuit such as a CPU (Central Processing Unit). The control unit 96 executes various processes by reading and executing programs (software) from the storage unit 94. The control unit 96 may execute processes using one CPU, or may be provided with multiple CPUs and execute processes using the multiple CPUs.

[0035] The control unit 96 acquires upstream data from the management device 100 via the communication unit 92. The upstream data includes, for example, transport target data such as the type, weight, and dimensions of the articles R to be loaded on the pallet, the perforations or zippers of the box, the number of glued pieces, the number of articles R, the arrangement of each article R on the pallet or the position where the articles R are loaded on the pallet, the order in which the articles R are unloaded from the pallet or the order in which they are loaded on the pallet, etc. The control unit 96 causes the imaging device 70 to capture an image at any timing and acquires image data. The control unit 96 processes the acquired image data to recognize the number, position, shape, size, etc. of the articles R present in the image data.

[0036] The control unit 96 determines the transport parameters of the upper gripping unit 20 and the side gripping unit 30 based on the image data and the transport target data. In this case, the image data may not be used. Here, the transport parameters include the rotation speed and rotation acceleration of the upper gripping unit 20 and the side gripping unit 30 by the rotation mechanism 14, the rising speed and rising acceleration of the upper gripping unit 20 and the side gripping unit 30 by the lifting mechanism 16, the suction pressure and suction time of the article R by the first suction mechanism 24, and the suction pressure and suction time of the article R by the second suction mechanism 34. In addition, the control unit 96 determines the transport parameters of the side gripping unit 30 based on the image data and the transport target data. Here, the transport parameters include whether or not the side gripping by the side gripping unit 30 is required, and the flip-up direction and angle of the side gripping unit 30. In this case, the image data is used. That is, the transport parameters are whether or not the first telescopic mechanism 44, the second telescopic mechanism 54, and the flip-up mechanism 60 are required to be operated, and the telescopic speed and telescopic acceleration. The control unit 96 controls the turning mechanism 14, the lifting mechanism 16, the first suction mechanism 24, the second suction mechanism 34, the first telescopic mechanism 44, the second telescopic mechanism 54, and the flip-up mechanism 60 based on the transport parameters. The control unit 96 also executes control for moving the gripping device 1 itself in the horizontal direction in the palletizing device to which the gripping device 1 is attached. When the palletizing device is a multi-joint robot, the horizontal movement of the gripping device 1 itself is achieved by the cooperative operation of multiple axes of the multi-joint robot.

[0037] The determination unit 97 is an arithmetic processing device similar to the control unit 96, and includes an arithmetic circuit such as a CPU (Central Processing Unit). The determination unit 97 executes various processes by reading and executing a program (software) from the storage unit 94. The determination unit 97 may be integrated with the control unit 96 and provided as one of the functions of the control unit 96.

[0038] The determination unit 97, like the control unit 96, acquires upstream data from the management device 100 via the communication unit 92. The upstream data includes at least transport target data such as the weight of the items R to be stacked on the pallet, the perforations or zipper parts of the box, and the number of glue points. The determination unit 97 causes the imaging device 70 to capture an image at any timing and acquires image data. The determination unit 97 processes the acquired image data to recognize the arrangement (layout), size, etc. of the multiple items R present in the image data. The determination unit 97 may acquire the transport target data, image data, etc. from the control unit 96.

[0039] The determination unit 97 determines whether the upper surface gripping unit 20 can be lifted by adsorbing multiple articles R, depending on the area of ​​the upper surface Ra of the articles R and the arrangement (layout) of the articles R. The determination unit 97 outputs the determination result to the control unit 96. The control unit 96 controls the movement of the upper surface gripping unit 20 depending on the determination result of the determination unit 97. That is, the determination unit 97 determines whether the upper surface gripping unit 20 can be lifted by adsorbing multiple articles R, or whether the upper surface gripping unit 20 cannot be lifted by adsorbing multiple articles R and can only be lifted by adsorbing one article R. When the determination unit 97 determines that the upper surface gripping unit 20 can be lifted by adsorbing multiple articles R, the control unit 96 moves the upper surface gripping unit 20 to a position facing the upper surfaces Ra of the multiple articles R. On the other hand, when the determination unit 97 determines that the upper surface gripping portion 20 can be adsorbed to and lifted by one article R, the control unit 96 moves the upper surface gripping portion 20 to a position facing the upper surface Ra of the single article R.

[0040] At this time, the determination unit 97 compares the suction area of ​​the upper gripping portion 20 with the total area of ​​the upper surfaces Ra of the multiple articles R, and when the suction area is equal to or greater than a determination ratio (e.g., 70%) of the total area, it determines that the upper gripping portion 20 can suction the multiple articles R and rise. Here, the suction area of ​​the upper gripping portion 20 is the area of ​​the first suction surface 22a of the first suction portion 22 of the upper gripping portion 20. Also, when multiple articles R are arranged adjacent to each other, it is the total area of ​​the upper surfaces Ra of the respective articles R. In this case, when multiple articles R are arranged adjacent to each other and there is a gap between the adjacent articles R, the total area includes the area of ​​the upper surfaces of the gap. In this embodiment, the determination ratio is set to 70%, but is not limited to this value. For example, the determination ratio may be adjusted according to the weight of one article R. For example, if the weight of one item R is greater than the reference value, the judgment ratio is set to greater than 70%, and if the weight of one item R is smaller than the reference value, the judgment ratio is set to less than 70%.

[0041] Further, the determination unit 97 determines whether or not the side gripping unit 30 needs to grip the side based on the image data and the transport object data. The control unit 96 controls the movement of the side gripping unit 30 according to the determination result of the determination unit 97. Specifically, the determination unit 97 determines that the side gripping unit 30 needs to suction the side Rb of the article R when the length of the perforation or zipper part of the upper surface Ra of the article R is longer than the length of one side of the upper surface Ra of the article R. The length of the perforation or zipper part or one side of the article R may be image data or transport object data. Here, the perforation or zipper part of the upper surface Ra of the article R and one side of the upper surface Ra of the article R are assumed to be approximately parallel. Furthermore, the length of the perforation or zipper part of the upper surface Ra of the article R is not the length along one side of the upper surface Ra of the article R but the actual length. When the number of perforations or zipper portions on the top surface Ra of the article R is greater than a preset reference number, the determination unit 97 determines that the side gripping unit 30 needs to suction the side surface Rb of the article R. The reference number is preferably set in advance through an experiment, a simulation, or the like.

[0042] Furthermore, when the number of glue points on the top surface Ra of the article R is less than a preset reference number, the determination unit 97 determines that the side gripping unit 30 needs to suction the side surface Rb of the article R. Here, the number of glue points on the top surface Ra of the article R is transport target data, and the reference number is preset through experiments, simulations, or the like.

[0043] The management device 100 is a system that manages the operation of each device in a logistics management facility in which the gripping device 1 of this embodiment is deployed. The management device 100 is, for example, a warehouse control system (WCS) or a warehouse management system (WMS), but is not limited to a WCS or a WMS and may be any system, for example, a back-end system such as other production management systems. The location at which the management device 100 is installed is arbitrary, and it may be installed in the facility in which the gripping device 1 is deployed, or may be installed at a location remote from the facility to manage the facility from the remote location.

[0044] <Control device processing> Next, a process flow for determining whether or not side gripping by the side gripping unit 30 is required during transportation by the gripping device 1 will be described. Here, a case in which a plurality of items R stacked on a pallet is unloaded will be described. FIG. 5 is a flowchart illustrating the process flow of the control device. The process shown in FIG. 5 is executed by the control unit 96 of the control device 90 based on a program and data previously stored in the memory unit 94. For example, the control device 90 receives a predetermined control signal from the management device 100 instructing the driving of the gripping device 1, and then proceeds to step S10 shown in FIG. 5 to start the process.

[0045] The control device 90 acquires the transport target data (step S10). In this embodiment, the control device 90 acquires the transport target data from the management device 100 via the communication unit 92. In this process, the transport target data includes at least data serving as a basis for determining whether the upper gripping unit 20 can adsorb and lift multiple objects R when lifting each object R to be unloaded by the gripping device 1, and data serving as a basis for determining whether side gripping by the side gripping unit 30 is necessary. For example, if the object R is small and light, side gripping is not necessary. The transport target data also includes data indicating the number and position (coordinates on the pallet) of each object R to be unloaded, and the order of unloading.

[0046] The control device 90 sets the number of executions i to i=1 and starts the loop process (step S12). In the loop process, while i≦n is satisfied, the processes from step S14 to step S20 are repeatedly executed n times. Here, n is the number of items R loaded on the pallet, and i indicates the order in which the items R are unloaded from the pallet.

[0047] The control device 90 acquires the captured image data (step S14). In this embodiment, the control device 90 causes the imaging device 70 to capture an image of a predetermined area including the i-th item R to be unloaded. In this case, the imaging device 70 outputs captured image data indicating data of the captured image to the control device 90. The captured image data may be linked to coordinate data of a coordinate system based on a predetermined position of the gripping device 1 or the facility in which the gripping device 1 is installed, for example. The control device 90 performs image processing on the captured image data to recognize the position, shape, size, arrangement (layout), etc. of the i-th item R to be unloaded.

[0048] The control device 90 determines whether the upper surface gripping part 20 can be lifted by adsorbing multiple articles R (step S16). In this embodiment, the control device 90 determines whether it is possible to pick up multiple articles R based on the image data acquired in step S14. For example, when the suction area of ​​the upper surface gripping part 20 is equal to or greater than a determined proportion (e.g., 70%) of the total area of ​​the upper surfaces Ra of the multiple articles R, it is determined that the upper surface gripping part 20 can be lifted by adsorbing multiple articles R. On the other hand, when the suction area of ​​the upper surface gripping part 20 is less than a determined proportion (e.g., 70%) of the total area of ​​the upper surfaces Ra of the multiple articles R, it is determined that the upper surface gripping part 20 cannot be lifted by adsorbing multiple articles R, and can only adsorb one article R. When the control device 90 determines that the upper surface gripping portion 20 is capable of adsorbing to multiple articles R and lifting, it moves the upper surface gripping portion 20 to a position facing the upper surfaces Ra of the multiple articles R, and when it determines that the upper surface gripping portion 20 is capable of adsorbing to one article R and lifting, it moves the upper surface gripping portion 20 to a position facing the upper surface Ra of the single article R.

[0049] The control device 90 determines whether side gripping is necessary (step S18). In this embodiment, the control device 90 determines whether side gripping is necessary based on the transport target data acquired in step S10. For example, if the i-th item R to be unloaded can be sufficiently lifted by the upper gripping unit 20 alone, it is determined that side gripping is unnecessary. If the control device 90 determines that side gripping is necessary (step S18; Yes), it proceeds to step S22. If the control device 90 determines that side gripping is not necessary (step S18; No), it proceeds to step S20.

[0050] When the control device 90 determines that side gripping is not necessary (step S18; No), it determines the flip-up direction and angle of the side gripping part 30 based on the captured image data acquired in step S14 (step S20). The flip-up direction indicates the position of the side gripping part 30 in the φ rotation direction. The flip-up angle indicates the position of the side gripping part 30 in the θ rotation direction. If there is an obstacle around the i-th item R to be unloaded, the side gripping part 30 may interfere with the obstacle. Specifically, if another item R is loaded adjacent to the side gripping part 30 side of the item R (the right side shown in FIG. 1), the side gripping part 30 may interfere with the adjacent item R when the upper gripping part 20 abuts against the upper surface Ra of the item R.

[0051] The positions of the side gripping unit 30 in the θ rotation direction and the φ rotation direction at the start of step S20 are, for example, the positions of the side gripping unit 30 when the (i-1)th item R is unloaded. In step S20, the control device 90 first acquires the position of the side gripping unit 30 in the φ rotation direction. The control device 90 then determines whether or not there is another item R that would be an obstacle in the direction of the side gripping unit 30 relative to the i-th item R, based on the captured image data acquired in step S14. If the control device 90 determines that there is no other item R that would be an obstacle, it decides to maintain the flip-up direction and angle of the side gripping unit 30, and proceeds to step S22.

[0052] When the control device 90 determines that there is another object R that is an obstacle, it determines the flip-up angle of the side gripping unit 30 so that the side gripping unit 30 can avoid the obstacle. When the control device 90 determines, for example, based on at least one of the transport object data and the captured image data, that the height dimension h of the other object R that is an obstacle is equal to or smaller than the height dimension h of the i-th object R, it determines the flip-up angle to be 90° (the position shown in FIG. 2). When the control device 90 determines, for example, based on at least one of the transport object data and the captured image data, that the height dimension h of the other object R that is an obstacle is greater than the height dimension h of the i-th object R and is smaller than a predetermined threshold, it determines the flip-up angle to be 180° (the position shown in FIG. 3). The predetermined threshold is set in advance by the configuration of the gripping device 1 other than the side gripping unit 30. For example, in the configuration of this embodiment, the predetermined threshold is set within a range where the second support unit 52 does not interfere at the 180° position shown in FIG. 3.

[0053] When the control device 90 determines, for example, based on at least one of the transport object data and the captured image data, that the height dimension h of the other obstructing object R is equal to or greater than a predetermined threshold, it decides to move the side gripping unit 30 in the φ rotation direction. The control device 90 determines, in the above-mentioned procedure, a flip-up angle at which the side gripping unit 30 can avoid the other obstructing object R when the side gripping unit 30 has moved 90°, 180°, or 270° in the φ rotation direction. After determining the flip-up direction and angle of the side gripping unit 30, the control device 90 proceeds to step S22.

[0054] The control device 90 transports (unloads) the i-th article R (step S22). First, the control device 90 controls the swivel mechanism 14 and the flip-up mechanism 60 according to the flip-up direction and angle determined in step S18, and positions the side gripping unit 30 in a predetermined posture. When side gripping is performed by the side gripping unit 30, the control device 90 controls the first extension mechanism 44 and the second extension mechanism 54 to extend and retract the first arm 40 and the second arm 50 based on the width dimension w of the i-th article R (see FIG. 1) so that the side gripping unit 30 is positioned at a suitable position on the side surface Rb of the article R.

[0055] Next, the control device 90 controls the gripping device 1 to move horizontally to a position where the first suction portion 22 of the upper gripping portion 20 faces the upper surface Ra of the article R. Next, the control device 90 controls the lifting mechanism 16 to lower the base 10 and the upper gripping portion 20 to a position where the first suction surface 22a of the first suction portion 22 abuts against the upper surface Ra of the article R. Next, the control device 90 operates the first suction mechanism 24 to suction the upper surface Ra of the article R to the first suction surface 22a. If it is determined in step S16 that side gripping is necessary, the control device 90 operates the second suction mechanism 34 to suction the side surface Rb of the article R to the second suction surface 32a. As a result, the gripping device 1 supports the article R. The control device 90 uses the lifting mechanism 16 to raise the gripping device 1 gripping the article R, transports it to a predetermined position, and unloads the i-th article R from the pallet.

[0056] The control device 90 resets the execution number i in the loop process as i=i+1, and returns to step S14 (step S24). When the process from step S14 to step S22 is executed n times and the unloading of n items R on the pallet is completed, the loop process ends.

[0057] 5, step S14 was performed for each item R, but for example, when the items R are arranged in a plane on the pallet, i.e., when multiple items R are not stacked vertically, step S14 of imaging all the items R on the pallet may be performed only once at the beginning. Also, in the process of this embodiment, the number and position (coordinate) data of each item R are included in the transport target data, but the number and positions of the items R may be obtained based on captured image data of all the items R on the pallet.

[0058] In addition, although the above description has been given of the process of unloading the article R from a pallet on which multiple articles R are loaded, the process of this embodiment shown in FIG. 5 can also be applied to the case of loading multiple articles R onto a pallet. In this case, in step S14, an image of a predetermined area including an area on the pallet where the article R is to be loaded is captured. In addition, in step S20, when loading the i-th article R at a predetermined position on the pallet, the direction and angle of the bounce are determined based on the presence or absence and dimensions of an obstacle in an area adjacent to the area where the article R is to be loaded. In this case, the obstacle is the 1st to i-1th articles R loaded.

[0059] Note that the determination by the control device 90 of whether the upper gripping part 20 can be lifted by adsorbing to multiple articles R (step S16) and the determination of whether side gripping by the side gripping part 30 is required (step S18) are not limited to those described above. For example, when the control device 90 determines that the upper gripping part 20 is adsorbed to multiple articles R and cannot be lifted, it executes a determination of whether side gripping by the side gripping part 30 is required. In other words, if there is side gripping by the side gripping part 30, the control device 90 determines whether the upper gripping part 20 can be lifted by adsorbing to multiple articles R.

[0060] <Unloading operation> FIG. 6 is a plan view for explaining the unloading operation by the gripping device. FIG. 7 is a cross-sectional view taken along the line II-II shown in FIG. 6. FIG. 8 is a cross-sectional view showing the state after FIG. 7. FIGS. 6 to 8 show the operation of unloading the item R4 among the items R1, R2, R3, and R4 arranged on the pallet P. The items R1, R2, R3, and R4 all have the same dimensions. The item R4 is arranged adjacent to the item R3 on the left side in the plan view shown in FIG. 6. Also, in FIGS. 6 to 8, only the upper gripping portion 20 and the side gripping portion 30 of the gripping device 1 are depicted. Also, the side gripping portion 30 is assumed to be in the 90° position shown in FIG. 2.

[0061] 6 and 7, in a state in which the first suction portion 22 of the upper surface gripping portion 20 is in contact with the upper surface Ra of the article R4, the side surface gripping portion 30 is positioned above the article R3. At this time, the lower end of the second suction portion 32 of the side surface gripping portion 30 is positioned a distance B above the lower end of the first suction portion 22 (see FIG. 2). Therefore, the second suction portion 32 of the side surface gripping portion 30 does not come into contact with the article R3. As shown in FIG. 8, the gripping device 1 of this embodiment can unload the article R4 only by suction by the first suction portion 22 of the upper surface gripping portion 20.

[0062] <Multiple piece determination process> 9 to 13 are plan views for explaining the results of the determination of whether or not the gripping device can pick up multiple articles. Note that Fig. 9 to Fig. 13 show multiple articles R stacked on a pallet as viewed from above in the vertical direction. In Fig. 9 to Fig. 13, the articles R are indicated by solid lines, and the first suction surface 22a of the first suction portion 22 in the upper gripping portion 20 is indicated by a two-dot chain line. That is, in Fig. 9 to Fig. 13, the area indicated by the two-dot chain line is the suction area C of the upper gripping portion 20.

[0063] 9 shows a "block stack" of multiple (12 in this embodiment) articles R. In the case of "block stacking," the suction area C of the first suction surface 22a of the first suction portion 22 in the upper surface gripping portion 20 is 90% of the total area of ​​the upper surface Ra of the four articles R. Therefore, when the judgment ratio is set to 70%, the upper surface gripping portion 20 can suction and lift four articles R at a time.

[0064] Fig. 10 shows a case where a plurality of (12 in this embodiment) articles R are "stacked in an alternating row". That is, "stacked in an alternating row" is a case where the arrangement of articles R shown in Fig. 9 and the arrangement of articles R shown in Fig. 10 are wrapped up alternately in the vertical direction. In the case of "stacked in an alternating row", the suction area C of the first suction surface 22a of the first suction portion 22 in the upper surface gripping portion 20 is 70% of the total area of ​​the upper surface Ra of the six articles R. Therefore, when the judgment ratio is set to 70%, the upper surface gripping portion 20 can suction and lift six articles R at a time.

[0065] FIG. 11 shows a "brick stack" of a plurality of (five in this embodiment) articles R. That is, the "brick stack" is a stack of articles R arranged as shown in FIG. 11(a) and as shown in FIG. 11(b) alternately wrapped in a vertical direction. In the case of the "brick stack", the suction area C1 of the first suction surface 22a of the first suction portion 22 in the upper surface gripping portion 20 in each step is 80% of the total area of ​​the upper surfaces Ra of the two articles R. Therefore, when the judgment ratio is set to 70%, the upper surface gripping portion 20 can suction and lift two articles R at one time. However, in the case of the "brick stack", the suction area C2 of the first suction surface 22a of the first suction portion 22 in the upper surface gripping portion 20 in each step is 40% of the total area of ​​the upper surfaces Ra of the two articles R. Therefore, when the judgment ratio is set to 70%, the upper surface gripping portion 20 cannot suction and lift two articles R at one time.

[0066] FIG. 12 shows a case where a plurality of articles R (four articles in this embodiment) are stacked in a "window stack". In the case of "window stack", the suction area C1 of the first suction surface 22a of the first suction portion 22 in the upper surface gripping portion 20 is 80% of the total area of ​​the upper surfaces Ra of the two articles R. Therefore, when the judgment ratio is set to 70%, the upper surface gripping portion 20 can suction and lift two articles R at a time. However, in the case of "window stack", the suction area C2 of the first suction surface 22a of the first suction portion 22 in the upper surface gripping portion 20 is 50% of the total area of ​​the upper surfaces Ra of the two articles R. Therefore, when the judgment ratio is set to 70%, the upper surface gripping portion 20 cannot suction and lift two articles R at a time.

[0067] 13 shows "double pinhole stacking" of multiple (four in this embodiment) articles R. In the case of "double pinhole stacking", the suction area C of the first suction surface 22a of the first suction portion 22 in the upper surface gripping portion 20 is 80% of the total area of ​​the upper surface Ra of the two articles R. Therefore, when the judgment ratio is set to 70%, the upper surface gripping portion 20 can suction and lift two articles R at a time.

[0068] [Effects of this embodiment] The gripping device of the first embodiment comprises an upper surface gripping unit 20 having a first adsorption surface 22a capable of adsorbing to an upper surface Ra of an article R, a determination unit 97 that determines whether the upper surface gripping unit 20 can adsorb to multiple articles R and rise depending on the area of ​​the upper surface Ra of the article R and the arrangement of the articles R, and a control unit 96 that controls the movement of the upper surface gripping unit 20 depending on the determination result of the determination unit 97.

[0069] According to the gripping device of the first aspect, the determination unit 97 determines whether the upper surface gripping unit 20 can be lifted by adsorbing to multiple articles R, depending on the area of ​​the upper surface Ra of the articles R and the arrangement of the articles R. When the upper surface gripping unit 20 can be lifted by adsorbing to multiple articles R, the control unit 96 moves the upper surface gripping unit 20 to a position facing the upper surfaces Ra of the multiple articles R, and when the upper surface gripping unit 20 cannot be lifted by adsorbing to multiple articles R, the control unit 96 moves the upper surface gripping unit 20 to a position facing the upper surface Ra of a single article R. Therefore, the upper surface gripping unit 20 can simultaneously grip and transport multiple articles R at one time as necessary, improving the transport capacity.

[0070] The gripping device according to the second aspect is the gripping device according to the first aspect, and further, the determination unit 97 compares the suction area of ​​the upper surface gripping portion 20 with the total area of ​​the upper surfaces Ra of the multiple articles R, and when the suction area is equal to or greater than a preset determination ratio of the total area, determines that the upper surface gripping portion 20 can be lifted by adsorbing to the multiple articles R. This makes it easy to determine whether the upper surface gripping portion 20 can be lifted by adsorbing to the multiple articles R.

[0071] The gripping device according to the third aspect is the gripping device according to the first or second aspect, and further includes a side gripping part 30 having a second suction surface 32a capable of suctioning to the side surface Rb of the article R, and a flip-up mechanism 60 capable of switching between a first state in which the side gripping part 30 is positioned below the lower end of the upper gripping part 20 and a second state in which the side gripping part 30 is positioned above the lower end of the upper gripping part 20, and a control part 96 controls the movement of the side gripping part 30 according to the determination result of the determination part 97. This allows the upper gripping part 20 and the side gripping part 30 to simultaneously grip and transport multiple articles R at once as necessary, thereby improving the transport capacity.

[0072] The gripping device according to the fourth aspect is the gripping device according to the third aspect, and further, the determination unit 97 determines that the side gripping unit 30 needs to adhere to the side surface Rb of the article R when the length of the perforation or zipper portion on the top surface Ra of the article R is longer than the length of one side of the top surface Ra of the article R. This makes it easy to determine whether the side gripping unit 30 can adhere to multiple articles R and lift them up.

[0073] The gripping device according to the fifth aspect is the gripping device according to the third or fourth aspect, and further, when the number of glue points on the upper surface Ra of the article R is less than a preset reference number, the determination unit 97 determines that the side gripping unit 30 needs to adhere to the side surface Rb of the article R. This makes it easy to determine whether the side gripping unit 30 can adhere to multiple articles R and lift them up.

[0074] The gripping method according to the sixth aspect includes a step of providing an upper surface gripping unit 20 having a first suction surface 22a capable of being suctioned to an upper surface Ra of an article R, and determining whether or not the upper surface gripping unit 20 can be lifted by adsorbing to a plurality of articles R according to the area of ​​the upper surface Ra of the article R and the arrangement of the articles R, and a step of controlling the movement of the upper surface gripping unit 20 when it is determined that the upper surface gripping unit 20 can be lifted by adsorbing to a plurality of articles R. This allows the upper surface gripping unit 20 to simultaneously grip and transport a plurality of articles R at one time as necessary, thereby improving the transport capacity.

[0075] Although the embodiments of the present disclosure have been described above, the embodiments are not limited to the contents of the description of these embodiments.

[0076] For example, in this embodiment, the side gripping portion 30, the first arm 40 and the second arm 50 rotate around the rotation axis A of the flip-up mechanism 60, thereby moving the side gripping portion 30 between a position below and a position above the lower end of the upper gripping portion 20, but this may also be achieved by translational movement in the Z-axis direction. [Explanation of symbols]

[0077] 1 Gripping device 10 base 10a Connecting part 12 Swivel shaft 14 Swivel mechanism 16 Lifting mechanism 20 Top grip part 20a First opposing surface 22 1st suction part 22a 1st suction surface 24 1st suction mechanism 30 Side grip part 30a 2nd facing surface 32 2nd suction part 32a 2nd suction surface 34 Second suction mechanism 40 1st arm 42 1st support part 44 1st telescopic mechanism 44a 1st fixed part 44b 1st moving part 50 2nd arm 52 Second support part 54 Second telescoping mechanism 54a 2nd fixed part 54b 2nd moving part 60 Flip-up mechanism 62 Fixed part 64 Rotating part 70 Imaging Device 80 I / O Devices 90 Control device 92 Communications Department 94 Memory section 96 Control Unit 97 Judgment section 100 Management device R Goods Ra top surface Rb side

Claims

1. An upper gripping portion having a first suction surface capable of being suctioned to an upper surface of an article; a determination unit that determines whether the upper gripping unit can be attracted to and lifted by the plurality of articles based on the area of ​​the upper surfaces of the articles and the arrangement of the articles; a control unit that controls movement of the upper gripping unit in response to a determination result of the determination unit; A gripping device comprising:

2. the determination unit compares an adsorption area of ​​the upper gripping portion with a total area of ​​the upper surfaces of the plurality of articles, and determines that the upper gripping portion can be adsorbed to the plurality of articles and lifted when the adsorption area is equal to or greater than a predetermined determination ratio of the total area. The gripping device according to claim 1 .

3. A side gripping portion having a second adsorption surface capable of adsorbing to a side surface of the article; The device further includes a flip-up mechanism that can switch between a first state in which the side gripping portion is positioned below a lower end of the upper gripping portion and a second state in which the side gripping portion is positioned above the lower end of the upper gripping portion, The control unit controls the movement of the side grip unit in accordance with the determination result of the determination unit. The gripping device according to claim 1 or 2.

4. The determination unit determines that suction to the side surface of the article by the side gripping unit is necessary when a length of a perforation or a zipper portion on the top surface of the article is longer than a length of one side of the top surface of the article. The gripping device according to claim 3.

5. the determination unit determines that suction to the side surface of the article by the side gripping unit is necessary when the number of glue points on the top surface of the article is less than a preset reference number. The gripping device according to claim 3.

6. An upper gripping portion having a first suction surface capable of being suctioned to an upper surface of an article, determining whether the upper gripping portion can adsorb and lift the multiple articles according to the area of ​​the upper surfaces of the articles and the arrangement of the articles; controlling movement of the upper gripping portion when it is determined that the upper gripping portion is capable of adsorbing to the plurality of articles and being lifted; The gripping method has the following features.

Images