Robot hand

Abstract

Provided is a robot hand capable of rotating an object in a vertical direction with a simple configuration.　This robot hand is for gripping an object and comprises: an opening / closing part that can be opened / closed by a pair of opposing wall parts approaching / separating from each other; and a pin protruding from one of the wall parts toward the other. The opening / closing part grips the object in a state where a position of the pin and a position of the centroid of the object are deviated from each other in a first direction along a horizontal plane due to the pair of wall parts approaching and closing.

Description

Robot Hand

[0001] The present disclosure relates to a robotic hand that grasps an object.

[0002] Conventionally, a robot hand has been used to pick (grasp), move, and place (place) an object, a so-called pick and place operation. A known conventional robot hand is a robot hand that reverses the orientation of an object when picking and placing (see Patent Document 1).

[0003] Japanese Patent Application Publication No. 2022-124023

[0004] The present disclosure provides a robot hand that has a simple configuration and is capable of rotating an object in the vertical direction.

[0005] One aspect of the present disclosure is a robotic hand that grasps an object, comprising: an opening / closing unit that can be opened and closed by a pair of opposing wall portions approaching and moving away from each other; and a pin that protrudes from one wall portion toward the other wall portion, and the opening / closing unit grasps the object in a state in which the position of the pin and the position of the center of gravity of the object are misaligned in a first direction along a horizontal plane by the pair of walls approaching and closing.

[0006] According to the present disclosure, an object can be rotated in the vertical direction with a simple configuration.

[0007] 1 is an external perspective view showing an example of the configuration and installation environment of a robot device according to a first embodiment of the present disclosure; 2 is an external perspective view showing an example of the configuration of a work pick section; 3 is an external perspective view showing an example of the configuration of a workplace section; 4 is an enlarged perspective view showing an example of the configuration of a robot hand; 5 is a view of the robot hand from the left side; 6 is a perspective view of the robot hand from the right side; 7 is a diagram for explaining, in time series, the pick operation in which the robot hand picks an object; 8 is a diagram for explaining, in time series, the place operation in which the robot hand places an object; 9 is a diagram for explaining, in time series, the rotation operation of the object by the robot hand;

[0008] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed description of well-known matters or redundant description of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0009] (Background to the Invention of the Embodiments of the Present Disclosure) When turning an object upside down, the robot hand of Patent Document 1 turns the object upside down by rotating the robot hand 180 degrees around an axis in a predetermined direction via a rotation mechanism of the robot body, etc. This requires an operation to drive the rotation mechanism of the robot body, which makes the configuration of the robot hand complex.

[0010] In the following embodiment, a robot hand that has a simple configuration and is capable of rotating an object in the vertical direction will be described.

[0011] (First embodiment)

[0012] <Configuration of Robot Device> Fig. 1A is an external perspective view showing an example of the configuration and installation environment of a robot device. Fig. 1B is an external perspective view showing an example of the configuration of a work pick unit. Fig. 1C is an external perspective view showing an example of the configuration of a workplace unit. As an example of the robot device, a robot device 50 shown in Fig. 1A etc. below is shown, but the configuration of the robot device 50 is not limited to this.

[0013] In this embodiment, for ease of explanation, in the drawings with arrows indicating directions, the X axis indicates the front-to-back direction, the Y axis indicates the left-to-right direction, and the Z axis indicates the up-to-down direction. The X axis and the Y axis are orthogonal to each other and are contained in a horizontal plane. The Z axis is contained in a vertical plane.

[0014] The robot device 50 performs picking (grasping) operations and placing (placing, storing) operations, i.e., pick-and-place operations. In response to control instructions from the robot control device 100 (see FIG. 7), the robot device 50 picks various objects WK (workpieces) to be grasped that are stored in the work pick unit 200, and moves them to the workplace unit 300 to place them. The work pick unit 200 is, for example, a storage case in which objects can be stored. The workplace unit 300 is, for example, an out-of-stock case from which objects can be out-stocked. The work pick unit 200 and the workplace unit 300 are placed, for example, on a belt conveyor, and can be interchanged as appropriate.

[0015] 1B , the work pick unit 200 is divided into one or more storage units 210. For example, one storage unit 210 stores one object WK and is the target of picking. The work pick unit 200 may store one type of object WK or multiple types of objects WK.

[0016] 1C , the workplace section 300 is divided into one or more storage sections 310. For example, one object WK is stored in one storage section 310 by a place. The workplace section 300 may store one type of object WK, or may store multiple types of objects WK.

[0017] 1A , the robot device 50 has a robot arm 10 and a robot hand 20. The robot arm 10 moves the robot hand 20 to any position in three-dimensional space. The robot hand 20 grasps an object WK. The robot device 50 has a motor and the like that supplies driving force to operate the robot arm 10 and the robot hand 20.

[0018] The robot device 50 is a manipulator having a multi-axis robot arm 10. The robot device 50 has a base 21 installed in a sorting area for objects WK, a production line, or the like. The base 21 adjusts, for example, the height at which the robot arm 10 can operate. The robot arm 10 includes, for example, a horizontally rotating swivel 23 attached to the top of the base 21, a rear arm 25 attached to the swivel 23 and swinging up and down, an upper arm 27 attached to the rear arm 25 and swinging up and down, and a wrist 29 attached to the upper arm 27. The wrist 29 includes a first drive unit 28 and a rotating unit 28A. The robot hand 20 is attached below the wrist 29, i.e., below the robot arm 10. The rotating unit 28A rotates around a rotation axis 31 (see FIG. 2A ) by the driving force of the first drive unit 28, thereby rotating the robot hand 20. The first drive unit 28 is, for example, a motor. The robot arm 10 holds the robot hand 20 so that it can move freely in three directions that are perpendicular to each other.

[0019] Fig. 2A is an enlarged perspective view showing an example of the configuration of a robot hand, Fig. 2B is a view of the robot hand as seen from the left side, and Fig. 2C is a plan view of the robot hand as seen from the right side.

[0020] The robot hand 20 has a second drive unit 33, an open / close support unit 37, a base unit 39, an open / close unit 40, and a pin 43. The second drive unit 33 supplies a drive force for opening and closing the open / close unit 40. The second drive unit 33 is, for example, a motor or an air cylinder. The second drive unit 33 extends and retracts the drive shaft 35 to change the width (length in the X direction) of the open / close support unit 37 and open or close the open / close unit 40. The open / close support unit 37 supports the open / close unit 40.

[0021] The base portion 39 has a pair of side walls 45 and a central wall portion 49 located between the pair of side walls 45. The side walls 45 and the central wall portion 49 contribute to gripping the object WK. Each of the pair of side walls 45 has an opening 47. The distance between the pair of side walls 45 of the base portion 39 does not change, i.e., the length along the X direction does not change.

[0022] The opening / closing unit 40 has a pair of walls 41. The pair of walls 41 are arranged opposite each other. The opening / closing unit 40 can be opened and closed by the pair of walls 41 approaching and moving away from each other in response to a driving force from the second drive unit 33. Specifically, the opening occurs when the walls 41 approach each other, and the moving away occurs when the walls 41 move away from each other. The distance between the pair of walls 41, i.e., the length along the X direction, of the opening / closing unit 40, changes. The pair of walls 41 can move in and out of the opening 47 depending on whether the opening / closing unit 40 is open or closed. For example, in the closed state, the pair of walls 41 are accommodated in the opening 47 of the pair of side walls 45, i.e., are located in the opening 47. In this case, the distance between the pair of walls 41 is a distance L3 (see FIG. 2C ). For example, in the open state, the pair of walls 41 are located outside the pair of side walls 45 of the base unit 39. In this case, the distance between the pair of walls 41 is a distance L4 (see FIG. 2C ). The wall 41 is, for example, arranged along the YZ plane and formed in a flat plate shape. The side wall portion 45 and the central wall portion 49 of the base portion 39 are also disposed along the YZ plane.

[0023] The pins 43 are provided so as to protrude from each of the wall portions 41 on one side of the opening / closing unit 40 toward the other wall portion 41. The pins 43 extend, for example, in a direction perpendicular (X-axis direction) to a plane (YZ plane) defined by the wall portions 41. The pins 43 are rotation support pins that contribute to the rotation of the object WK in the vertical direction (Z direction) when the object WK grasped by the robot hand 20 is placed. The pins 43 are, for example, cylindrical (for example, a perfect circular cylindrical shape), but may be other shapes.

[0024] The pair of pins 43 are connected to the pair of wall portions 41 at positions offset from the center of the wall portions 41 in the X direction (see state D3 in FIG. 4 ). The length of the pair of pins 43 is such that they do not come into contact with the center wall portion 49 when the pair of wall portions 41 are closest to each other.

[0025] The pin 43 may be made of any material, such as rubber. If the friction between the pin 43 and the object WK increases depending on the material of the pin 43, the rotation moment increases, and the amount of rotation increases.

[0026] The robot hand 20 grasps, for example, two objects WK simultaneously. The robot hand 20 may grasp one object WK by sandwiching it between one wall portion 41 and one surface of the central wall portion 49. The robot hand 20 may grasp another object WK by sandwiching it between the other wall portion 41 and the other surface of the central wall portion 49. When grasping the object WK, the lower surface of the object WK may or may not come into contact with the pin 43.

[0027] The pair of side walls 45 of the base portion 39 reinforce the gripping force of the pair of walls 41 of the opening / closing portion 40. This is because the area of ​​contact with the object WK from the side can be the sum of the area of ​​contact of the wall portions 41 and the area of ​​contact of the side walls 45, thereby increasing the gripping force. Furthermore, the side walls 45 can prevent the object WK from wobbling when the grip of the object WK is released and the object WK rotates and falls, and the pin 43 allows the object WK to rotate stably on one axis. Note that the side walls 45 do not necessarily have to be provided.

[0028] <Opened and Closed States of the Robot Hand> Next, the opened and closed states of the robot hand 20 will be described.

[0029] The open / closed states of the robot hand 20 include at least a grasping preparation state, a grasping state, and a grasping release state.

[0030] The grasp preparation state is a state in which the opening / closing unit 40 is wide open before the robot hand 20 begins grasping the object WK. In the grasp preparation state, the pair of pins 43 are not positioned inside (absent from) the pair of side wall portions 45 of the base portion 39. In this case, even if the object WK is positioned between the side wall portions 45 and the central wall portion 49 of the base portion 39 to grasp the object WK, the pins 43 do not come into contact with the object WK. This makes it easier for the robot hand 20 to insert the pins 43 below the object WK and grasp it. Note that in the grasp preparation state, it is sufficient that the pins 43 do not come into contact with the object WK before grasping. Therefore, for example, in the grasp preparation state, if the distance between the pair of side wall portions 45 in the X direction can be ensured to be longer than the length of the object WK, the pair of pins 43 may be positioned inside the pair of side wall portions 45 of the base portion 39.

[0031] The grasping state is a state in which the robot hand 20 grasps the object WK and the opening / closing unit 40 is closed. In the grasping state, the wall 41 of the opening / closing unit 40 and the central wall 49 of the base unit 39 of the robot hand 20 come into contact with the object WK, and the robot hand 20 clamps the object WK.

[0032] The released grip state is a state in which the grip is slightly more open than the grip state, but less open than the grip preparation state. In the released grip state, the distance between the wall 41 of the opening / closing unit 40 and the central wall 49 of the base 39 is longer than the width (length in the X direction) of the object WK, so the object is released from being clamped by the robot hand 20. On the other hand, in the released grip state, movement of the object WK in the X direction is restricted, and at least a portion of the pin 43 extending from the wall 41 toward the central wall 49 is positioned below the object WK. Therefore, when the object WK falls, it comes into contact with and engages with the pin 43, and the object WK receives a rotational force.

[0033] <Operation of Robot Hand 20> Next, the operation of the robot hand 20 will be described.

[0034] 3 to 6, states AX (where X is a number), BX, CX, DX, EX, and FX have the same X number and represent the same timing, but are shown at different angles. Also, the smaller the X number, the earlier the timing.

[0035] FIG. 3 is a diagram for explaining, in time series, the picking operation in which the robot hand 20 picks up the target object WK.

[0036] First, under the control of the robot control device 100, the robot hand 20 approaches the target object WK stored in the work pick unit 200 with the opening / closing unit 40 open (state A1), and gradually approaches the target object WK (states A2 and B2). With the opening / closing unit 40 wide open (prepared for grasping), the robot hand 20 inserts the pin 43 between the underside of the target object WK and the mounting surface of the work pick unit 200. Then, when the opening / closing unit 40 is closed, the robot hand 20 enters a grasping state, and grasps the target object WK with the pin 43 below the underside of the target object WK (states A3 and B3). In this case, the robot hand 20 grasps the target object WK by sandwiching it between the pair of walls 41 of the opening / closing unit 40 and the central wall 49 of the base unit 39.

[0037] FIG. 4 is a diagram for explaining, in time series, the placing operation in which the robot hand 20 places the object WK.

[0038] The robot hand 20 grasps the object WK with the pin 43 positioned below the bottom surface of the object WK (state A3 in FIG. 3 , state B3 in FIG. 3 , state C3 in FIG. 4 , state D3 in FIG. 4 ). The robot hand 20 maintains this posture of the object WK and moves to a predetermined position (for example, above the workplace section 300) under the control of the robot control device 100.

[0039] The pin 43 is disposed offset in the Y direction from the center position of the wall 41. When grasping the object WK, if the center position of the wall 41 in the Y direction and the center of gravity of the object WK coincide with each other, the object WK is grasped with the position of the pin 43 offset in the Y direction from the center of gravity of the object WK (state D3).

[0040] When the robot hand 20 arrives at a predetermined position under the control of the robot control device 100, the open-close unit 40 opens slightly from the gripping state, increasing the distance between the wall 41 of the open-close unit 40 and the central wall 49 of the base 39. The clamping of the object WK is loosened enough that the pin 43 does not slip out of the underside of the object WK, and the clamping is released. At this time, the underside of the object WK (the surface in the negative Z direction), which is a part of the object WK, rests on and engages with the pin 43 (state D4). Therefore, the object WK begins to rotate vertically (specifically, along the YZ plane) around the pin 43 due to gravity (states C4 and D4). As the object WK starts to rotate, its angle with respect to the XY plane (e.g., the horizontal plane) begins to change (state D5).

[0041] 5A to 5C are diagrams for explaining, in time series, the rotational operation of the target object WK by the robot hand 20. In each state, Fig. 5A to 5C show perspective views of the negative X-direction from the central wall portion 49 of the base portion 39.

[0042] When the robot hand 20 releases the grip on the object WK and the object WK starts to rotate, the orientation of the object WK is the same as the up-down orientation when it was stored in the work pick unit 200 (state C4 in FIG. 4 , state D4 in FIG. 4 , state E4 in FIG. 5 ). Because the position of the pin 43 and the center of gravity of the object WK are misaligned in the Y direction, the object WK rotates downward (clockwise in FIG. 5 ) from the center of gravity of the object WK, with the pin 43 as the fulcrum (state E5 → state E6 → state E7 → state E8 → state E9).

[0043] The amount of rotation of the object WK depends on at least one of the following: the shape of the object WK, the weight of the object WK, the frictional force acting between the object WK and the pin 43, and the downward movement distance (fall distance) of the object WK. For example, the rotation causes the object WK to rotate 180 degrees from the up-down orientation in which it was stored in the work pick unit 200, and to assume an up-down inverted orientation (state E9).

[0044] The shape of the object WK may be any shape as long as it can be grasped by the robot hand 20. For example, the surface of the object WK that comes into contact with the pin 43 when the robot hand 20 releases its grip may be flat. For example, the object WK may have a shape with a recess in the center when stored in the work pick unit 200, as shown in FIG. 5 , or may have a simple rectangular parallelepiped shape. If the object WK has such a recess, the pin 43 engages with the recess, making it easier to transmit rotational force, increasing the amount of rotation and allowing the object to be turned upside down, for example. Furthermore, if the object WK has a rectangular parallelepiped shape, the rotational force of the pin 43 is not very large, but it can still be rotated, for example, 90 degrees.

[0045] FIG. 6 is a diagram for explaining the time series of the rotational insertion of the target object WK into the place destination by the robot hand 20.

[0046] When placing the object WK, the robot hand 20 moves to a position above a predetermined storage section 310 in the workplace 300 at a predetermined distance from the storage section 310 under the control of the robot control device 100. At this position, the robot hand 20 releases its grip on the object WK, and the object WK begins to rotate (state E4 in FIG. 5 , state F4 in FIG. 6 ). The object WK rotates vertically around the pin 43 as a fulcrum due to gravity (state F5 → state F6 → state F7 → state F9). The object WK falls into the storage section 310 in an upside-down orientation from the upside-down orientation in which it was stored in the work pick section 200, and is stored there (state F8). Note that the distance between the position of the storage section 310 in the workplace 300 and the position of the robot hand 20 at the time of release of grip may be set so that the amount of rotation of the object WK is appropriate.

[0047] <Configuration of Picking System> Next, the configuration of the picking system will be described. Fig. 7 is a diagram showing an example of the configuration of the picking system 5 in the first embodiment. The picking system 5 includes a robot device 50 and a robot control device 100.

[0048] The robot control device 100 controls the robot device 50 in real time to perform the desired picking operation and placing operation. The robot control device 100 can monitor the operation of the robot device 50 in real time and transmit predetermined instruction information to the robot control device 100.

[0049] The robot control device 100 includes a processor 110 , a memory 120 , an external interface 130 , an input device 140 , a display device 150 , and a communication device 160 .

[0050] The processor 110 may be configured using, for example, a Central Processing Unit (CPU), a Digital Signal Processor (DSP), or a Graphics Processing Unit (GPU). The processor 110 may be configured using various integrated circuits (for example, a Large Scale Integration (LSI) or a Field Programmable Gate Array (FPGA)). The processor 110 realizes various functions by executing programs stored in the memory 120. The processor 110 comprehensively controls each section of the robot control device 100 and performs various processes.

[0051] The processor 110 controls the operation of the robot device 50 via the external interface 130 (also referred to as an external IF). For example, the processor 110 may control the operation of the robot arm 10 and the robot hand 20 of the robot device 50, thereby controlling the picking operation and the placing operation by the robot device 50. In this case, the processor 110 may instruct the control of the movement of the robot hand 20 and the control of the opening and closing of the opening / closing unit 40.

[0052] The memory 120 includes a random access memory (RAM) or a read only memory (ROM). The memory 120 may be an external storage medium or may be detachable from the robot control device 100. The memory 120 stores various types of data, information, programs, etc.

[0053] The external interface 130 is connected to an external device via a wired or wireless connection to transmit and receive various data or information. The external device may include the robot arm 10 or the robot hand 20 of the robot device 50. The external interface 130 may, for example, control the drive units of the robot arm 10 or the robot hand 20 to control the movement and operation of the robot arm 10 or the robot hand 20 of the robot device 50 (for example, opening and closing of the opening / closing unit 40).

[0054] The input device 140 may include various buttons, keys, a keyboard, a touch panel, a microphone, a sensor, or other input devices. The input device 140 accepts input of various data or information. The input device 140 is operated by a user. The user is, for example, a manager or an operator who manages pick-and-place by the robotic device 50.

[0055] The display device 150 is, for example, a liquid crystal display or an organic EL display. The display device 150 displays various data or information. The display on the display device 150 may be confirmed by, for example, a user.

[0056] The communication device 160 communicates various data or information according to a wired or wireless communication method. The communication method used by the communication device 160 may include a local area network (LAN), a wide area network (WAN), a mobile phone network, or a power line communication method.

[0057] It should be noted that instead of the external interface 130 , a communication device 160 may communicate with the robot arm 10 and the robot hand 20 of the robot device 50 .

[0058] Although the robot control device 100 has been described as having each component and function in a single device, this is not limiting. For example, the components and functions of the robot control device 100 may be distributed and configured as a system (robot control system). The system may be configured as a cloud-based system on a network, or as an on-premise server device.

[0059] In this manner, the robot hand 20 of this embodiment can flip the object WK vertically (up and down) when picking and placing the object WK, and then insert and store it in the workspace unit 300. By employing mechanical ingenuity, the robot hand 20 can rotate the object WK without rotating the axis of the robot hand 20. Specifically, the robot hand 20 includes a pin 43 connected to the opening / closing unit 40. By shifting the position of the pin 43 and the center of gravity of the object WK while gripping the object WK, the robot hand 20 can rotate the object WK (e.g., flip it upside down) around the pin 43 as a fulcrum when releasing the grip. This drop is, for example, a free fall. Furthermore, by shifting the position of the pin 43 and the center of gravity of the object WK, the robot hand 20 can maintain a constant rotation direction of the object WK.

[0060] In the present embodiment, the robot hand 20 is illustrated as simultaneously grasping two objects WK, but this is not limiting. The robot hand 20 may simultaneously grasp only one object WK, or may simultaneously grasp three or more objects WK. The robot hand 20 grasps, for example, two objects WK simultaneously. The robot hand 20 grasps the object using at least the wall portions 41 of the opening / closing unit 40. When the robot hand 20 grasps only one object WK, the central wall portion 49 of the base portion 39 may be absent, and the object may be sandwiched and grasped between the pair of wall portions 41 of the opening / closing unit 40. Furthermore, the pins 43 may not be provided in pairs, but may be connected to only one of the pair of wall portions 41.

[0061] In the present embodiment, the pin 43 is disposed offset from the center position of the wall 41 in the Y direction relative to the wall 41, but this is not limited to this. The position of the pin 43 does not have to be offset from the center position of the wall 41 in the Y direction. In other words, the position of the pin 43 and the center position of the wall 41 in the Y direction may coincide. Even in this case, if the object WK is grasped in a state in which the center position of the wall 41 in the Y direction is offset from the center position of the object WK, the robot hand 20 can rotate the object WK in the vertical direction with the pin 43 as a fulcrum by releasing the grasp.

[0062] In the present embodiment, the object WK is illustrated as rotating clockwise in Figures 4 to 6, but this is not limiting. The robot hand 20 may grasp the object WK so that the object WK rotates counterclockwise in Figures 4 to 6.

[0063] Specifically, when the object WK rotates clockwise, the robot hand 20 grasps the object WK so that the center of gravity of the object WK is located to the right (positive side in the Y direction) of the pin 43. In this case, when the object WK is released from the grasp, it rotates from right to bottom to left in the direction of the arrow in state D4 in FIG. 4 if the object WK is turned upside down. Therefore, the opening / closing unit 40 may grasp the object WK so that the position of the pin 43 and the center of gravity of the object WK are in this order in the positive direction of the Y direction (rightward). The rightward direction here corresponds to the direction (rightward) at the start of rotation when the object WK is rotated after being grasped.

[0064] Furthermore, when the object WK rotates counterclockwise, the robot hand 20 grasps the object WK so that the center of gravity of the object WK is located to the left (negative side in the Y direction) of the pin 43. In this case, when the object WK is released from the grasp, it rotates in the direction opposite to the arrow in state D4 in FIG. 4 , from left to bottom to right if the object WK is upside down. Therefore, the opening / closing unit 40 may grasp the object WK in the negative direction of the Y direction (leftward) so that the position of the pin 43 and the center of gravity of the object WK are in this order. The leftward direction here corresponds to the direction (leftward) at the start of rotation when the object WK is rotated after being grasped.

[0065] In the present embodiment, the wall 41 of the opening / closing unit 40 is disposed along a vertical plane (including the Z direction) perpendicular to a horizontal plane, but this is not limiting. The wall 41 of the opening / closing unit 40 may be inclined with respect to the vertical plane.

[0066] In the present embodiment, the protruding length of the pin 43 relative to the wall portion 41 is fixed, but this is not limiting. The protruding length of the pin 43 relative to the wall portion 41 may be variable and adjustable. In this case, the degree of contact between the target object WK and the pin 43 when the grip is released can be adjusted.

[0067] (Summary of the embodiment) As described above, the present disclosure describes at least the following matters. Note that, in parentheses, examples of components corresponding to the above-described embodiment are shown, but the present disclosure is not limited to these.

[0068] (Item 1) A robot hand (robot hand 20) that grasps an object (object WK), comprising: an opening / closing unit (opening / closing unit 40) that can be opened and closed by a pair of opposing wall units (wall units 41) approaching and moving away from each other; and a pin (pin 43) that protrudes from one wall unit toward the other wall unit, wherein the opening / closing unit grasps the object in a state where the position of the pin and the position of the center of gravity of the object are misaligned in a first direction (Y direction) along a horizontal plane by the pair of walls approaching and closing.

[0069] As a result, when the opening / closing section is opened, the object is released from being pinched by the pair of first walls of the opening / closing section, and the object is grasped above the pin, so that the robot hand can use the positional deviation to rotate and drop the object using gravity with the pin as a fulcrum. This allows the robot hand to rotate the object vertically with a simple configuration and reduce the load on the robot hand.

[0070] (Item 2) The robot hand according to Item 1, wherein the opening / closing unit grasps the object so that the position of the pin and the position of the center of gravity of the object are in that order in the first direction, and the orientation of the first direction is a direction at the start of rotation when rotating the object after grasping it.

[0071] This allows the robot hand to rotate the object using the direction from the pin toward the center of gravity of the object as the direction at the start of rotation.

[0072] (Item 3) The robot hand according to Item 1 or 2, wherein the pin is disposed at a position offset from a center position of the wall portion along the first direction.

[0073] As a result, the position of the pin is offset from the center of the first wall, so that even if the opening / closing unit grips the object by aligning the center of the object with the center of the wall in the first direction, the position of the pin and the center of gravity of the object will be offset. This allows the robot hand to stably grip the object and to suitably rotate the object when placing it.

[0074] (Item 4) A robot hand according to any one of items 1 to 3, further comprising a base portion (base portion 39) having a pair of side wall portions (side wall portions 45), each of the pair of side wall portions being arranged along the wall portion and having an opening portion (opening portion 47), and the pair of wall portions being able to freely move in and out of the opening portion depending on whether the opening / closing portion is opened or closed.

[0075] As a result, the robot hand can grasp an object using the base portion, and the robot hand can smoothly open and close the opening / closing portion, i.e., grasp an object, by having an opening in the base portion.

[0076] (Item 5) The robot hand according to Item 4, wherein the pin is absent inside the pair of side wall portions before grasping the object.

[0077] This allows the robot hand to prevent the pin from interfering with the gripping action of the object before gripping the object.

[0078] (Item 6) The robot hand according to Item 4 or 5, wherein when gripping the object, each of the pair of wall portions is positioned in the opening of the pair of side wall portions.

[0079] As a result, when the robot hand grasps an object, the side wall portion assists the wall portion to sandwich the object, allowing the robot hand to grasp the object more stably.

[0080] (Item 7) The robot hand according to any one of Items 4 to 6, wherein, when the grip of the object is released, at least a portion of the pair of wall portions is positioned outside the pair of side wall portions, and at least a portion of the pin is positioned inside the pair of side wall portions.

[0081] This allows the robot hand to loosen its grip on the object when it releases it, and the pins can contact the object above the pins, allowing it to rotate and drop. At this time, the wall can reduce the wobble of the object when it rotates, allowing it to rotate and drop stably.

[0082] (Item 8) The robot hand according to any one of Items 4 to 7, wherein the base portion includes a central wall portion (central wall portion 49) disposed along the wall portions between the pair of wall portions, and the opening / closing portion grasps a plurality of objects between the pair of wall portions and the central wall portion by closing the opening / closing portion.

[0083] This allows the robot hand to pick and place multiple objects simultaneously with a simple configuration.The robot hand can also rotate multiple objects simultaneously in the vertical direction using the pins.

[0084] (Item 9) The robot hand according to any one of claims 1 to 8, wherein the pin is made of rubber.

[0085] As a result, the pin has a certain degree of friction, so the robot hand can increase the rotation moment of the object relative to the pin when placing it, thereby increasing the amount of rotation, making it easier to rotate by 180 degrees, for example. Therefore, when placing, the robot hand can more easily store the object in the storage section by turning it upside down compared to when picking.

[0086] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0087] This disclosure is based on a Japanese patent application (Patent Application No. 2024-149022) filed on August 30, 2024, the contents of which are incorporated herein by reference.

[0088] The present disclosure is useful for a robot hand or the like that is capable of rotating an object in the vertical direction with a simple configuration.

[0089] 5 Picking system 10 Robot arm 20 Robot hand 39 Base section 40 Opening / closing section 41 Wall section 43 Pin 45 Side wall section 47 Opening section 49 Central wall section 50 Robot device 100 Robot control device 110 Processor 120 Memory 130 External interface 140 Input device 150 Display device 160 Communication device 200 Work pick section 210 Storage section 300 Workplace section 310 Storage section WK Object

Claims

1. A robot hand for grasping an object, comprising: an opening / closing unit that can be opened and closed by a pair of opposing wall sections approaching and moving away from each other; and a pin that protrudes from one wall section toward the other wall section, wherein the opening / closing unit grasps the object in a state in which the position of the pin and the position of the center of gravity of the object are misaligned in a first direction along a horizontal plane by the pair of walls approaching and closing.

2. The robot hand according to claim 1, wherein the opening / closing unit grasps the object so that the position of the pin is followed by the position of the center of gravity of the object in the first direction, and the orientation of the first direction is the direction in which the object starts to rotate after being grasped.

3. The robot hand according to claim 1 or 2, wherein the pin is arranged at a position offset from the center position of the wall portion along the first direction.

4. A robot hand as described in claim 1 or 2, further comprising a base portion having a pair of side wall portions, each of the pair of side wall portions being arranged along the wall portion and having an opening, and the pair of wall portions being able to freely move in and out of the opening depending on the opening and closing of the opening / closing portion.

5. The robot hand according to claim 4, wherein the pin of the opening / closing section is not located inside the pair of side wall sections before grasping the object.

6. The robot hand according to claim 4, wherein when the object is grasped, the opening / closing section has the pair of wall portions each positioned in the opening of the pair of side wall portions.

7. A robot hand as described in claim 4, wherein when the opening / closing part releases the grip of the object, at least a portion of the pair of wall portions is positioned outside the pair of side wall portions, and at least a portion of the pin is positioned inside the pair of side wall portions.

8. The robot hand according to claim 4, wherein the base portion includes a central wall portion disposed between and along the pair of wall portions, and the opening / closing portion grasps a plurality of objects between the pair of wall portions and the central wall portion when closed.

9. The robot hand according to claim 1 or 2, wherein the pins are made of rubber.

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