Gripping device and method

Abstract

Provided is a gripping device and method comprising: an upper surface gripping unit having a first adhesively holding surface that can adhesively hold an upper surface of an article; a determination unit that determines whether the upper surface gripping unit can be raised together with a plurality of articles adhesively held thereby according to the area of the upper surface of the article and arrangement of the article; and a control unit that controls movement of the upper surface gripping unit according to the determination result from the determination unit.

Description

Grip device and method

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

[0002] 2. Description of the Related Art There are known conveying devices such as palletizing devices that stack articles on trays such as pallets. For example, Patent Document 1 (JP-A-2005-102666) describes a gripping device in a conveying device that grips an article by suction onto the top surface of the article.

[0003] Patent No. 6793428

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

[0005] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a gripping device and method that can improve conveying capacity.

[0006] In order to achieve the above-mentioned object, the gripping device of the present disclosure comprises an upper surface gripping unit having a first suction surface that can be adsorbed 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 raised based on the area of ​​the upper surface of the objects and the arrangement of the objects, and a control unit that controls the movement of the upper surface gripping unit based on the determination result of the determination unit.

[0007] The gripping method disclosed herein also includes a step of providing an upper gripping unit having a first suction surface capable of adsorbing to the upper surface of an object, determining whether the upper gripping unit can adsorb to a plurality of objects and lift based on the area of ​​the upper surface of the object and the arrangement of the object, and controlling the movement of the upper gripping unit when it is determined that the upper gripping unit can adsorb to a plurality of objects and lift.

[0008] The gripping device and method of the present disclosure can improve transport capacity.

[0009] 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. FIG. 5 is a flowchart illustrating the processing flow of a control device. FIG. 6 is a plan view schematically illustrating the unloading operation by the gripping device. FIG. 7 is a cross-sectional view taken along line II-II shown in FIG. 6. FIG. 8 is a cross-sectional view showing the state after FIG. 7. FIG. 9 is a plan view schematically illustrating the result of a determination as to whether multiple items can be picked up by the gripping device. FIG. 10 is a plan view schematically illustrating the result of a determination as to whether multiple items can be picked up by the gripping device. FIG. 11 is a plan view schematically illustrating the result of a determination as to whether multiple items can be picked up by the gripping device. FIG. 12 is a plan view schematically illustrating the result of a determination as to whether multiple items can be picked up by the gripping device. FIG. 13 is a plan view for schematically explaining the result of determining whether or not the gripping device can pick up multiple articles.

[0010] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are easily replaceable by those skilled in the art, those that are substantially identical, or those that are equivalent. Furthermore, the components in the following embodiments can be variously omitted, replaced, or modified without departing from the gist of the present disclosure. In the following embodiments, components necessary for illustrating the embodiments will be described, and other components will be omitted. The same components will be assigned the same reference numerals, and different components will be assigned different reference numerals.

[0011] [Embodiment] <Configuration of Grip Device> Fig. 1 is a schematic diagram of a grip device according to this embodiment. Fig. 2 is a schematic diagram showing a 90° flip-up mode of the grip device shown in Fig. 1. Fig. 3 is a schematic diagram showing a 180° flip-up mode of the grip device shown in Fig. 1. Fig. 4 is a schematic block diagram of the grip device shown in Fig. 1. The grip device 1 shown in Figs. 1 to 4 is attached to a palletizing device as a conveying device, and is a device that stacks articles on a pallet, unloads articles from a pallet, or transfers articles from one pallet to another in a facility that is subject to logistics management, such as a warehouse.

[0012] Here, the Japan Pallet Association defines a pallet as "a surface on which a single unit of cargo can be placed, with a structure that allows for all loading, transport, and storage by hand or by dedicated vehicles such as forklifts. This includes those with superstructures." In this embodiment, a pallet refers to a container or platform on which goods R are stacked. In other words, the pallet referred to here is not limited to a so-called flat platform, but also includes a cart or the like, and may be of any shape. Goods R are stacked on a pallet, such as goods to be shipped. Note that the term "goods R" also refers to cardboard boxes and the like in which goods are packaged. At least the top surface Ra of the goods R is flat, 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 also includes an embodiment in which the functions of each device are configured as part of a palletizing device to which the gripping device 1 is attached or a conveyance system in which the palletizing device is deployed.

[0014] In this embodiment, the articles R are stacked on a pallet, with the upper side in the vertical direction being the top surface Ra and the side in the horizontal direction perpendicular to the vertical direction being the side surface Rb. The direction perpendicular to the second opposing surface 30a that faces the side surface Rb when the side surface gripping unit 30 supports the side surface Rb of the article R 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 that faces 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 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 pivoting shaft 12, a turning mechanism 14, and an elevating mechanism 16. The pivoting shaft 12 is fixed to the upper surface of the base 10 so that its axis is parallel to the Z-axis direction. The base 10 and the pivoting shaft 12 are supported rotatably in a rotational direction φ, which is about the axis of the pivoting shaft 12, relative to the arm of the palletizing device.

[0016] The turning mechanism 14 shown in Figure 4 turns the base 10 and the turning shaft 12 in a rotation direction φ. For example, if the palletizing device is an articulated robot, the turning of the turning shaft 12 by the turning mechanism 14 corresponds to the operation of the sixth axis of the articulated 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 swivel 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 swivel 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 swivel shaft 12 by the lifting mechanism 16 corresponds to the operation of a linear joint in the vertical direction 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 unit 20 is provided on the lower part of the base 10. The upper surface gripping unit 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 unit 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 unit 20 moves up and down and rotates in accordance with the lifting and rotating movements of the base 10 and the rotating shaft unit 12. The upper surface gripping unit 20 has a first suction portion 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. However, it may be, for example, a plurality of suction pads protruding downward from the first opposing surface 20 a of the upper gripping unit 20. The first suction unit 22 has a first suction surface 22 a at its lower end. When the first suction surface 22 a abuts against the upper surface Ra of the article R, the first suction unit 22 adheres to the upper surface Ra of the article R with the first suction surface 22 a by activating 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 22 a via an air pipe (not shown) and configured to suck air from the first suction surface 22 a. 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 unit 30 is provided on a side of the base 10 in the X-axis direction via a first arm 40, a second arm 50, and a flip-up mechanism 60. The side gripping unit 30 has a second opposing surface 30a that faces the side surface Rb of the article R. The side gripping unit 30 is movable in the longitudinal direction of the first arm 40 relative to the base 10 by a first extension / contraction mechanism 44 (described later). The side gripping unit 30 is also movable in the longitudinal direction of the second arm 50 relative to the base 10 by a second extension / contraction mechanism 54 (described later). The side gripping unit 30 is also rotatable 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 top gripping unit 20 and the second suction surface 32a of the side gripping unit 30.

[0021] The side gripping unit 30 is movable relative to the top gripping unit 20 within the X-Z 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 movement 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 movable relative to the top gripping unit 20 in the Y-axis direction. The side gripping unit 30 has a second suction unit 32 on the second opposing surface 30a that is capable of suctioning the article R.

[0022] In the examples shown in FIGS. 1 to 3 , the second suction portion 32 is depicted as a single block. However, it may be, for example, a plurality of suction pads protruding from the second opposing surface 30a of the side gripping portion 30. The second suction portion 32 has a second suction surface 32a at the end opposite 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 portion 32 adheres to the side surface Rb of the article R with the second suction surface 32a by activating 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 configured to suck air from the second suction surface 32a. For example, if the second suction portion 32 is configured with 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 configuration 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 unit 30 faces the side surface Rb of the article R. In this configuration, the second suction surface 32a of the second suction unit 32 faces the side surface Rb of the article R. Also, in this configuration, the entire second suction surface 32a is located below the first suction surface 22a. In the configuration 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 configuration, the second suction surface 32a of the second suction unit 32 faces vertically downward. Also, in this configuration, 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 a 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 portion 42 and a first extension / contraction mechanism 44. The first support portion 42 is located at one end of the first arm 40 in the longitudinal direction. The first support portion 42 is connected to the second arm 50. The first support portion 42 supports the first extension / contraction mechanism 44 and is connected to the side grip portion 30 via the first extension / contraction mechanism 44. In this embodiment, the first support portion 42 has a frame shape that houses and supports the first fixed portion 44a of the first extension / contraction mechanism 44. The first extension / contraction mechanism 44 extends along the longitudinal direction of the first arm 40 and is extendable and contractible in a first extension / contraction direction F1, which is the longitudinal direction of the first arm 40. In the state shown in Figure 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 extension / retraction mechanism 44 is pre-extended / 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 portion 44a and a first movable portion 44b. The first fixed portion 44a is fixed to the first support portion 42. The first fixed portion 44a supports the first movable portion 44b so that the first movable portion 44b can move linearly in the first telescopic direction F1 within a predetermined range. The first movable portion 44b is movable in the first telescopic direction F1 relative to the first fixed portion 44a. One longitudinal end of the first movable portion 44b is supported by the first fixed portion 44a. The other longitudinal end of the first movable portion 44b is fixed to the side gripping portion 30. The first telescopic mechanism 44 may be realized by a well-known mechanism such as a cylinder, an electric actuator, a wire, or a link mechanism having a cylindrical first fixed portion 44a and a rod-shaped first movable portion 44b.

[0026] The second arm 50 is provided on a side of the base 10 in the X-axis direction via a flip-up mechanism 60. The second arm 50 has a second support portion 52 and a second extension / contraction mechanism 54. The second support portion 52 is located at one end of the second arm 50 in the longitudinal direction. The second support portion 52 is connected to the flip-up mechanism 60. The second support portion 52 supports the second extension / contraction mechanism 54 and is connected to the first support portion 42 of the first arm 40 via the second extension / contraction mechanism 54. In this embodiment, the second support portion 52 has a frame shape that houses and supports the second fixed portion 54a of the second extension / contraction mechanism 54. The second extension / contraction mechanism 54 extends along the longitudinal direction of the second arm 50 and is extendable and contractible in a second extension / contraction direction F2, which is the longitudinal direction of the second arm 50. In the state shown in Figure 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 / retraction mechanism 54 is pre-extended / 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 portion 54a and a second movable portion 54b. The second fixed portion 54a is fixed to the second support portion 52. The second fixed portion 54a supports the second movable portion 54b so that the second movable portion 54b can move linearly in the second telescopic direction F2 within a predetermined range. The second movable portion 54b is movable in the second telescopic direction F2 relative to the second fixed portion 54a. One longitudinal end of the second movable portion 54b is supported by the second fixed portion 54a. The other longitudinal end of the second movable portion 54b is fixed to the first support portion 42 of the first arm 40. The second telescopic mechanism 54 may be realized by a well-known mechanism such as a cylinder having a cylindrical second fixed portion 54a and a rod-shaped second movable portion 54b, an electric actuator, a wire, or a link mechanism.

[0028] The flip-up mechanism 60 is switchable 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 top gripping portion 20 (in this embodiment, the first suction surface 22 a of the first suction portion 22) 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 top gripping portion 20. The flip-up mechanism 60 is connected to the top 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 40 and the second arm 50. The flip-up mechanism 60 of this embodiment is provided on a side of the base 10 in the X-axis direction. The flip-up mechanism 60 rotates the second arm 50, the first arm 40, and the side gripping portion 30 relative to the base 10 in a rotational direction θ about a rotation axis A parallel to the Y-axis direction.

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

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

[0031] The imaging device 70 captures images of the pallet on which the items R are to be loaded or unloaded, the items R loaded on the pallet, and the stacked arrangement of the items R, and outputs image data that can identify the position and individual items of the imaged objects to the control device 90. The imaging device 70 is placed in a position where the pallet and the items R loaded on the pallet can be observed. At this time, the imaging device 70 captures images of all (plural) items R loaded on the pallet, thereby capturing the stacked arrangement of the multiple items R, i.e., the layout of the multiple items R. The imaging device 70 may be attached to the gripping device 1 or may be placed 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 the worker inputs various pieces of information for operating the gripping device 1, and an output device for presenting various pieces of information to the worker. 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 such as a liquid crystal display device or an organic EL (Electro Luminescence) display device, a light-emitting device such as an LED (Light Emitting Diode), 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 memory 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 external devices such as the management device 100, and may include, for example, an antenna. In this embodiment, wireless communication is assumed as the communication method used by the communication unit 92, but any communication method may be used. The memory 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 main storage device such as a random access memory (RAM), a read-only memory (ROM), 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 a single 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 items R to be stacked on the pallet, the perforations or zippers on the box, the number of glued items, the arrangement of each item R on the pallet or the position where each item R is stacked on the pallet, and the order in which the items R are unloaded from the pallet or stacked on the pallet. 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 items R present in the image data.

[0036] The control unit 96 determines transport parameters for the upper gripping unit 20 and the side gripping unit 30 based on the image data and the transport object data. In this case, image data does not need to 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 item R by the first suction mechanism 24, and the suction pressure and suction time of the item R by the second suction mechanism 34. The control unit 96 also determines transport parameters for the side gripping unit 30 based on the image data and the transport object data. Here, the transport parameters include whether or not side gripping by the side gripping unit 30 is required, and the direction and angle of the side gripping unit 30 to flip up. In this case, image data is used. That is, the transport parameters include whether or not the first extension / contraction mechanism 44, the second extension / contraction mechanism 54, and the flip-up mechanism 60 are required to be operated, and the extension / contraction speed and extension / contraction 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 to move the gripping device 1 itself in the horizontal direction in the palletizing device to which the gripping device 1 is attached. If 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 programs (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 transport target data such as at least the weight of the items R to be stacked on the pallet, the perforations or zippers of the boxes, and the number of glued items. 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 also 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 adsorb and lift up multiple articles R based on the area of ​​the upper surfaces 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 based on the determination result of the determination unit 97. That is, the determination unit 97 determines whether the upper surface gripping unit 20 can adsorb and lift up multiple articles R, or whether the upper surface gripping unit 20 cannot adsorb and lift up multiple articles R and can only adsorb and lift up one article R. When the determination unit 97 determines that the upper surface gripping unit 20 can adsorb and lift up 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 unit 20 can be adsorbed to one item R and raised, the control unit 96 moves the upper surface gripping unit 20 to a position facing the upper surface Ra of the one item R.

[0040] At this time, the determination unit 97 compares the suction area of ​​the upper surface gripping unit 20 with the total area of ​​the upper surfaces Ra of the multiple articles R, and determines that the upper surface gripping unit 20 can suction and lift the multiple articles R if the suction area is equal to or greater than a determination percentage (e.g., 70%) of the total area. Here, the suction area of ​​the upper surface gripping unit 20 refers to the area of ​​the first suction surface 22a of the first suction portion 22 of the upper surface gripping unit 20. Furthermore, when multiple articles R are arranged adjacent to each other, the total area refers to the total area of ​​the upper surfaces Ra of the multiple articles R. In this case, when multiple articles R are arranged adjacent to each other and there is a gap between adjacent articles R, the total area includes the area of ​​the upper surfaces of the gap. Note that, although the determination percentage is set to 70% in this embodiment, it is not limited to this value. For example, the determination percentage may be adjusted according to the weight of each 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] The determination unit 97 also determines whether or not side gripping by the side gripping unit 30 is necessary 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 suction to the side Rb of the article R by the side gripping unit 30 is necessary 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. The length of the perforation or zipper portion or one side of the article R may be image data or transport object data. Here, the perforation or zipper portion on the top surface Ra of the article R and one side of the top surface Ra of the article R are assumed to be approximately parallel. Furthermore, the length of the perforation or zipper portion on the top surface Ra of the article R is the actual length, not the length along one side of the top surface Ra of the article R. When the number of perforations or zipper portions on the top surface Ra of the article R is greater than a predetermined reference number, the determination unit 97 determines that the side gripping unit 30 needs to suction the article R to the side surface Rb. The reference number is preferably set in advance through an experiment, simulation, or the like.

[0042] Furthermore, when the number of glued 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 glued points on the top surface Ra of the article R is transport target data, and the reference number is set in advance through experiments, simulations, etc.

[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 WCS (Warehouse Control System) or a WMS (Warehouse Management System), but is not limited to a WCS or a WMS and may be any system, such as a back-end system such as another production management system. The management device 100 may be installed at any location, and may be installed within 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 that location.

[0044] <Processing of the control device> Next, a process flow for determining whether side gripping by the side gripping unit 30 is required during transport by the gripping device 1 will be described. Here, a case where multiple items R stacked on a pallet are 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 programs and data pre-stored in the memory unit 94. For example, upon receiving a predetermined control signal from the management device 100 instructing the gripping device 1 to be driven, the control device 90 proceeds to step S10 shown in FIG. 5 and starts 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 that serves as a basis for determining whether the upper gripping unit 20 can adsorb and lift multiple items R when lifting each item R to be unloaded by the gripping device 1, and data that serves as a basis for determining whether side gripping by the side gripping unit 30 is necessary. For example, if the item 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 item R to be unloaded, and the order in which they will be unloaded.

[0046] The control device 90 sets the execution number i to i=1 and starts the loop process (step S12). In the loop process, while i≦n holds, the processes from step S14 to step S20 are repeated n times, where 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 item R, which is the i-th item 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 in a coordinate system based on, for example, a predetermined position of the gripping device 1 or the facility in which the gripping device 1 is deployed. 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, which is to be unloaded.

[0048] The control device 90 determines whether the upper surface gripping unit 20 can lift up 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 adsorption area of ​​the upper surface gripping unit 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 unit 20 can lift up by adsorbing multiple articles R. On the other hand, when the adsorption area of ​​the upper surface gripping unit 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 unit 20 cannot lift up by adsorbing multiple articles R, and can only lift up one article R. When the control device 90 determines that the upper surface gripping portion 20 can be adsorbed to multiple items R and raised, it moves the upper surface gripping portion 20 to a position facing the upper surfaces Ra of the multiple items R, and when it determines that the upper surface gripping portion 20 can be adsorbed to one item R and raised, it moves the upper surface gripping portion 20 to a position facing the upper surface Ra of the one item 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] If the control device 90 determines that side gripping is not necessary (step S18; No), it determines the direction and angle of the side gripping unit 30 to be flipped up based on the captured image data acquired in step S14 (step S20). The flip-up direction indicates the position of the side gripping unit 30 in the φ rotation direction. The flip-up angle indicates the position of the side gripping unit 30 in the θ rotation direction. If there is an obstacle around the i-th item R to be unloaded, the side gripping unit 30 may interfere with the obstacle. Specifically, if another item R is stacked adjacent to the side gripping unit 30 (to the right as shown in FIG. 1 ) of the item R, the side gripping unit 30 may interfere with the adjacent item R when the upper gripping unit 20 abuts 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, based on the captured image data acquired in step S14, whether there are any other items R that would obstruct the i-th item R in the direction of the side gripping unit 30. If the control device 90 determines that there are no other items R that would obstruct the i-th item R, it determines to maintain the lift-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 obstructing object R, it determines the bounce angle of the side gripping unit 30 so that the side gripping unit 30 can avoid the obstacle. For example, when the control device 90 determines, based on at least one of the transport object data and the captured image data, that the height dimension h of the obstructing object R is equal to or less than the height dimension h of the i-th object R, it determines the bounce angle to be 90° (the position shown in FIG. 2 ). For example, when the control device 90 determines, based on at least one of the transport object data and the captured image data, that the height dimension h of the obstructing object R is greater than the height dimension h of the i-th object R but less than a predetermined threshold, it determines the bounce 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. In the configuration of this embodiment, for example, the predetermined threshold is set within a range where the second support portion 52 does not interfere at the 180° position shown in FIG. 3 .

[0053] For example, when the control device 90 determines, based on at least one of the transport object data and the captured image data, that the height dimension h of the obstructing object R is equal to or greater than a predetermined threshold, it determines to move the side gripping unit 30 in the φ rotation direction. The control device 90 determines, using the above procedure, the bounce angle at which the side gripping unit 30 can avoid the obstructing object R when the side gripping unit 30 has moved 90°, 180°, or 270° in the φ rotation direction. After determining the bounce 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 item R (step S22). The control device 90 first controls the rotation 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 performing side gripping by the side gripping unit 30, the control device 90 also controls the first extension / retraction mechanism 44 and the second extension / retraction 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 item R (see FIG. 1 ) so that the side gripping unit 30 is positioned at a suitable position on the side surface Rb of the item R.

[0055] Next, the control device 90 controls the gripping device 1 to move horizontally until the first suction portion 22 of the upper surface gripping unit 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 surface gripping unit 20 until the first suction surface 22a of the first suction portion 22 abuts the upper surface Ra of the article R. Next, the control device 90 activates the first suction mechanism 24 to adsorb 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 activates the second suction mechanism 34 to adsorb the side surface Rb of the article R to the second suction surface 32a. This allows the gripping device 1 to support the article R. The control device 90 then 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 item R from the pallet.

[0056] The control device 90 resets the execution number i in the loop processing to i = i + 1 and returns to step S14 (step S24). After executing the processing from step S14 to step S22 n times and completing the unloading of n items R from the pallet, the loop processing ends.

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

[0058] Furthermore, although the above description concerns the process of unloading an item R from a pallet on which multiple items R are stacked, the process of this embodiment shown in FIG. 5 can also be applied to the case of stacking multiple items R on a pallet. In this case, in step S14, an image of a predetermined area on the pallet including the area where the item R is to be stacked is captured. In addition, in step S20, when stacking the i-th item R at a predetermined position on the pallet, the direction and angle of the bounce are determined based on the presence and size of an obstacle in an area adjacent to the area where the item R is to be stacked. In this case, the obstacle is the first to i-1th items R stacked.

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

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

[0061] 6 and 7, when the first suction portion 22 of the top gripping unit 20 is in contact with the top surface Ra of the article R4, the side gripping unit 30 is positioned above the article R3. At this time, the lower end of the second suction portion 32 of the side gripping unit 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 gripping unit 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 simply by suction with the first suction portion 22 of the top gripping unit 20.

[0062] <Multiple-item Pickup Determination Process> Figures 9 to 13 are plan views schematically illustrating the results of determining whether multiple items can be picked up by the gripping device. Figures 9 to 13 show multiple items R stacked on a pallet as viewed from above in the vertical direction. In Figures 9 to 13, the items R are represented by solid lines, and the first suction surface 22a of the first suction portion 22 of the upper surface gripping unit 20 is represented by a two-dot chain line. In other words, the area represented by the two-dot chain line in Figures 9 to 13 is the suction area C of the upper surface gripping unit 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 surfaces Ra of the four articles R. Therefore, if the determination ratio is set to 70%, the upper surface gripping portion 20 can suction and lift four articles R at a time.

[0064] Figure 10 shows an "alternate stack" of multiple (12 in this embodiment) articles R. In other words, "alternate stacking" is achieved by wrapping the arrangement of articles R shown in Figure 9 and the arrangement of articles R shown in Figure 10 alternately in the vertical direction. In the case of "alternate 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 70% of the total area of ​​the upper surface Ra of the six articles R. Therefore, when the determination 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 multiple (five in this embodiment) articles R. That is, the "brick stack" is formed by alternately wrapping the arrangement of articles R shown in FIG. 11( a) and the arrangement of articles R shown in FIG. 11( b) in the 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 of 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, if the determination 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 the "brick stack," the suction area C2 of the first suction surface 22a of the first suction portion 22 of 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, if the determination ratio is set to 70%, the upper surface gripping portion 20 cannot suction and lift two articles R at a time.

[0066] 12 shows a stack of multiple (four in this embodiment) articles R stacked in a "window stacking" fashion. In the case of "window stacking," 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, if the determination 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 stacking," 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, if the determination 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, if the determination 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 aspect comprises an upper surface gripping unit 20 having a first suction surface 22a that can be adsorbed to the upper surface Ra of the item R, a determination unit 97 that determines whether the upper surface gripping unit 20 can be adsorbed to multiple items R and raised depending on the area of ​​the upper surface Ra of the item R and the arrangement of the items 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 adsorb to and lift up multiple articles R, depending on the area of ​​the upper surfaces Ra of the articles R and the arrangement of the articles R. When the upper surface gripping unit 20 can adsorb to and lift up 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 lift up because it has adsorbed 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 once as needed, thereby improving transport capacity.

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

[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 unit 30 having a second suction surface 32a that can be attached to the side surface Rb of the article R, and a flip-up mechanism 60 that can switch between a first state in which the side gripping unit 30 is positioned below the lower end of the top gripping unit 20, and a second state in which the side gripping unit 30 is positioned above the lower end of the top gripping unit 20, and a control unit 96 controls the movement of the side gripping unit 30 in accordance with the determination result of the determination unit 97. This allows the top gripping unit 20 and the side gripping unit 30 to simultaneously grip and transport multiple articles R at once as necessary, thereby improving 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.

[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 glued 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.

[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 adsorbing to the upper surface Ra of the articles R, and determining whether the upper surface gripping unit 20 can adsorb and lift up multiple articles R based on the area of ​​the upper surface Ra of the articles 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 adsorb and lift up multiple articles R. This allows the upper surface gripping unit 20 to simultaneously grip and transport multiple articles R at once as needed, thereby improving 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 can also be achieved by translational movement in the Z-axis direction.

[0077] REFERENCE SIGNS LIST 1 Grip device 10 Base 10a Connecting portion 12 Swivel shaft portion 14 Swivel mechanism 16 Lifting mechanism 20 Upper gripping portion 20a First opposing surface 22 First suction portion 22a First suction surface 24 First suction mechanism 30 Side gripping portion 30a Second opposing surface 32 Second suction portion 32a Second suction surface 34 Second suction mechanism 40 First arm portion 42 First support portion 44 First extension / retraction mechanism 44a First fixed portion 44b First movable portion 50 Second arm portion 52 Second support portion 54 Second extension / retraction mechanism 54a Second fixed portion 54b Second movable portion 60 Flip-up mechanism 62 Fixed portion 64 Rotating portion 70 Imaging device 80 Input / output device 90 Control device 92 Communication unit 94 Memory unit 96 Control unit 97 Judgment unit 100 Management device R Article Ra Top surface Rb Side surface

Claims

1. A gripping device comprising: an upper surface gripping unit having a first suction surface capable of being adsorbed to the upper surface of an object; a determination unit that determines whether the upper surface gripping unit can be adsorbed to a plurality of 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.

2. The gripping device described in claim 1, wherein the determination unit compares the suction area of ​​the upper gripping portion with the total area of ​​the upper surfaces of the multiple articles, and determines that the upper gripping portion can be adsorbed to the multiple articles and lifted when the suction area is equal to or greater than a predetermined determination percentage of the total area.

3. A gripping device as described in claim 1 or claim 2, further comprising: a side gripping portion having a second suction surface capable of being attached to the side of the article; and a flip-up mechanism capable of switching between a first state in which the side gripping portion is positioned below the lower end of the top gripping portion, and a second state in which the side gripping portion is positioned above the lower end of the top gripping portion, wherein the control portion controls the movement of the side gripping portion depending on the determination result of the determination portion.

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

5. The gripping device according to claim 3, wherein the determination unit determines that adhesion to the side 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.

6. A gripping method comprising: an upper surface gripping portion having a first suction surface capable of being adsorbed to the upper surface of an object; a step of determining whether or not the upper surface gripping portion can be adsorbed to a plurality of objects and lifted depending on the area of ​​the upper surface of the object and the arrangement of the object; 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 a plurality of objects and lifted.

Images