Robot and article size acquisition method

Abstract

A robot is disclosed. The robot includes a holding portion, a pulling-out portion, a sensor, and a size acquisition portion. The holding portion is capable of holding an article placed on a support. The pulling-out portion is capable of pulling out the holding portion toward the front. The sensor detects a situation in which the article is no longer on the support due to the article being pulled out. The size acquisition portion acquires a size of a pulling-out direction of the article based on a distance by which the article is pulled out from a time at which the article is pulled out by the pulling-out portion until the sensor detects the situation in which the article is no longer on the support.

Description

Technical Field

[0001] This invention relates to a robot for obtaining the dimensions of an object. Background Technology

[0002] Robots have been used to retrieve and transport items located in designated areas. Patent Document 1 discloses such a robot.

[0003] Patent Document 1 describes a robotic picking system that removes boxes from an unstructured pallet. This robotic picking system determines the size and position of the boxes on the pallet, and the location of specific boxes, using computer vision and / or one or more "preliminary picks."

[0004] The initial pickup involves the robot and its attached gripper slightly lifting the outermost box from the corner to separate it from the top layer. The system calculates the difference between the images before and after separation to determine the size of the box to be removed and the position of the topmost box.

[0005] Patent Document 1: Japanese Patent Publication No. 2019-509559 Summary of the Invention

[0006] In the structure of Patent Document 1 mentioned above, sometimes when the box is surrounded by other objects, the size of the box cannot be obtained by computer vision. Therefore, a structure that can obtain the size in a different way than before is needed.

[0007] In view of the above, the object of the present invention is to obtain the dimensions of the pull-out direction of the item regardless of whether the item is covered or not.

[0008] The problem to be solved by the present invention is as described above. Hereinafter, the solution to solve the problem and its effects will be explained.

[0009] According to a first aspect of the present invention, a robot with the following structure is provided. That is, the robot includes a holding part, a pulling part, a sensor, and a size acquisition part. The holding part is capable of holding an item placed on a support. The pulling part is capable of pulling the holding part forward. The sensor detects that the item is no longer on the support due to being pulled out. The size acquisition part acquires the size of the item in the pulling direction based on the distance the item has been pulled out from the moment the pulling out begins (starting from the pulling out part) to the moment the sensor detects that the item is no longer on the support.

[0010] According to a second aspect of the present invention, a method for obtaining the size of an item is provided. That is, the method includes a pull-out step, a detection step, and an acquisition step. In the pull-out step, an item placed on a support is pulled forward by at least one of a robot body and an end effector. In the detection step, a sensor detects that the item is no longer on the support due to being pulled out. In the acquisition step, the size of the item in the pull-out direction is obtained based on the distance the item has been pulled out from the start of the pull-out step to the moment the sensor detects that the item is no longer on the support.

[0011] In this way, the pulling direction of the item can be determined based on the timing of the loss of support from the support structure during the pulling process.

[0012] (The effect of the invention)

[0013] According to the present invention, the dimensions of the pull-out direction of the article can be obtained regardless of whether the article is covered or not. Attached Figure Description

[0014] Figure 1 This is a perspective view showing the overall structure of a robot according to an embodiment of the present invention.

[0015] Figure 2 It is a 3D image of a robotic hand.

[0016] Figure 3 This is a 3D view of the robot's hand from the side of the robot itself.

[0017] Figure 4 This is a functional block diagram showing the electrical structure of a robot.

[0018] Figure 5 This diagram illustrates the robot's actions in acquiring the depth dimensions of an object.

[0019] Figure 6 This is a side view illustrating other actions by which the robot acquires the depth dimensions of an object.

[0020] Figure 7 This is a flowchart illustrating the processes performed in the robot. Detailed Implementation

[0021] Next, with reference to the accompanying drawings, the disclosed embodiments will be described. Figure 1 This is a perspective view showing the overall structure of robot 1 according to an embodiment of the present invention. Figure 2 This is a 3D model of the robot arm 20. Figure 3 This is a 3D view of the robot arm 20 from the side of the robot body 10.

[0022] Figure 1 The unpacking robot (robot) 1 shown is used to remove items 5 arranged in three dimensions within container 6 from container 6 and move them to a designated location. The designated location may be, for example, the conveyor belt shown in the illustration, but is not limited to this.

[0023] In this embodiment, item 5 is a box, specifically a rectangular cardboard box. The box can contain objects or be empty.

[0024] Hereinafter, the front and back sides of the arranged items 5 as viewed from the perspective of robot 1 will be referred to as "front" and "back".

[0025] Robot 1 includes robot body 10, robot hand (end effector) 20 and controller 60.

[0026] The robot body 10 is configured as a known vertical joint robot. The robot's degrees of freedom can be 4 or 6, but are not limited to these.

[0027] The robotic arm 20 is fixed to the front end of the robot body 10. The robotic arm 20 can be moved in various ways by the robot body 10, so that it can move in various directions or change its orientation.

[0028] The controller 60 is configured as a known computer, including a CPU, ROM, RAM, etc. The controller 60 is capable of controlling the movements of the robot body 10 and the robot hand 20.

[0029] Secondly, the structure of the robotic arm 20 will be described in detail. For example... Figure 2 as well as Figure 3 As shown, the robot hand 20 includes a mounting base 30, a guide (receiving) part 31, a sliding base 32, an adsorption part (holding) part 33, a pull-out device 34, a cylinder 35, and a camera 36.

[0030] The robotic hand 20 is mounted on the front end of the robot body 10. Therefore, by appropriately moving the arm of the robot body 10, the robotic hand 20 can be positioned in various postures. However, as... Figures 1 to 3 As shown, the robot hand 20 of this embodiment is typically used in a posture where the plate-shaped guide portion 31 is located on the lower side and the thickness direction of the guide portion 31 is vertical. This posture is sometimes referred to as the basic posture. Hereinafter, in the description of the structure of the robot hand 20, the orientations such as "up" and "down" refer to the orientations in the basic posture state.

[0031] The mounting base 30 is framed by mutually fixing plate-like components. The mounting base 30 is fixed to the front end of the robot body 10.

[0032] The guide portion 31 is an elongated plate-shaped component. One end of the guide portion 31 along its length is fixed to the lower part of the mounting base 30. The guide portion 31 is roughly rectangular in shape when viewed from above. Figure 2 As shown, a pair of guide rails 40 are arranged parallel to each other on the upper surface of the guide portion 31. The length direction of the guide rails 40 is consistent with the length direction of the guide portion 31.

[0033] The sliding base 32 is a small plate-shaped component. A pair of brackets 41 are fixed to the lower part of the sliding base 32. The brackets 41 are mounted on the guide rail 40, and the guide rail 40 and the brackets 41 constitute a linear guide device. This linear guide device allows the sliding base 32 to move linearly along the length of the guide portion 31.

[0034] The adsorption unit 33 is mounted on the upper surface of the sliding base 32. The adsorption unit 33 includes a back plate 42 and a plurality of adsorption pads 43.

[0035] The back plate 42 is a plate-shaped component. The back plate 42 is mounted on the sliding base 32 with its thickness direction oriented towards the length direction of the guide portion 31. The back plate 42 is supported relative to the sliding base 32 via a lifting mechanism of the cylinder 35 (described later). Therefore, the back plate 42 can be raised and lowered relative to the sliding base 32.

[0036] The adsorption pad 43 is a hollow pad formed in the shape of a corrugated tube. Multiple adsorption pads 43 are arranged in a matrix on the side of the back plate 42 away from the mounting base 30. Openings are formed in the adsorption pad 43 facing the side opposite to the mounting base 30.

[0037] A negative pressure passage (not shown) is formed inside the back plate 42, and this negative pressure passage is connected to a suitable negative pressure source. Therefore, by providing negative pressure to the adsorption pad 43 while bringing the opening of the adsorption pad 43 close to or in contact with the surface of the article 5, the surface of the article 5 can be adsorbed and held in place. The adsorption pad 43 is configured to be deformable, allowing it to easily adhere tightly to the surface of the article 5. Therefore, the adsorption effect is improved.

[0038] The pull-out device 34 pulls out the item 5 adsorbed by the adsorption part 33 in a generally horizontal direction by sliding the adsorption part 33 via the sliding base 32. Figure 2 As shown, the pull-out device 34 includes a motor 44, a speed reduction device 45, a drive roller 46, a driven roller 47, and a belt 48.

[0039] The motor 44 is configured as an electric motor capable of both forward and reverse rotation. The housing of the motor 44 is fixed to the lower part of the mounting base 30.

[0040] The reduction gear 45 reduces the rotation speed of the motor 44 and transmits the speed to the drive roller 46. The reduction gear 45 is, for example, composed of a reduction gear system (not shown). The housing of the reduction gear 45 is fixed to the lower part of the mounting base 30.

[0041] The drive roller 46 is positioned near the end of the guide portion 31 along its length, close to the mounting base 30. The drive roller 46 is rotatably supported by the mounting base 30. The axis of rotation of the drive roller 46 is horizontal and parallel to the width direction of the guide portion 31.

[0042] The driven roller 47 is disposed at the end of the guide portion 31 on the side away from the mounting base 30 in the longitudinal direction. A recess is formed at the front end of the guide portion 31, and the driven roller 47 is disposed in the recess. The driven roller 47 is rotatably supported by the guide portion 31. The axis of rotation of the driven roller 47 is horizontal and parallel to the width direction of the guide portion 31.

[0043] A belt 48 forms a ring and is wound around the drive roller 46 and the driven wheel 47. Viewed from above, the belt 48 is positioned at the center of the guide portion 31 in the width direction. The belt 48 is arranged around the guide portion 31. A fixing member 49 is mounted on the belt 48 on the upper surface of the guide portion 31. A sliding base 32 is fixed to the belt 48 by the fixing member 49.

[0044] The pull-out device 34 described above can drive the belt 48 by rotating the motor 44. As the belt 48 moves, the suction part 33 and the sliding base 32 can move together along the length direction of the guide part 31.

[0045] like Figure 3 As shown, the first position sensor 57 is disposed at the end of the sliding base 32 away from the mounting base 30 within its range of motion, and the second position sensor 58 is disposed at the end closer to the mounting base 30. The first position sensor 57 and the second position sensor 58 can detect the sliding base 32 (in other words, the adsorption part 33) at the limits of its range of motion. The structures of the first position sensor 57 and the second position sensor 58 are arbitrary; for example, they can be reflective light sensors that detect the sliding base 32.

[0046] The surface of belt 48 functions as a transport surface for transporting item 5. When item 5 is placed on top of guide 31 on belt 48, belt 48 can be driven by drive motor 44 to transport item 5 along the length of guide 31.

[0047] Cylinder 35 is configured as a pneumatic cylinder. For example... Figure 3 As shown, cylinder 35 is mounted on the back plate 42 of adsorption unit 33 with its axis pointing vertically. The cylindrical part of cylinder 35 is fixed to the side of back plate 42, and the front end of the rod is fixed to sliding base 32. Cylinder 35 is connected to a compressed air source (not shown). The adsorption unit 33 can be raised and lowered by switching the supply of compressed air to cylinder 35.

[0048] A pair of sliding guide devices 50 are provided on the sliding base 32. The sliding guide devices 50 can guide the direction of the suction unit 33 to rise and fall.

[0049] The camera 36 is mounted on the upper part of the mounting base 30. The camera 36 is configured as a stereo camera, for example. The orientation of the camera 36 is approximately the same as the direction in which the guide portion 31 protrudes from the mounting base 30.

[0050] Camera 36 can photograph the front side of item 5 through the opening of container 6. The width W and height H of the retrieved object 5 can be obtained by performing image analysis on the obtained image by a computer (e.g., controller 60).

[0051] The surface of item 5, excluding its front side, is covered by other items 5 or containers 6. Therefore, it is extremely difficult to obtain depth D from the image of camera 36.

[0052] Secondly, refer to Figure 2 The structure of the front-side support item 5 used for the detection guide 31 will be described.

[0053] The support shaft 55 of the driven roller 47 constituting the pull-out device 34 is supported by the guide 31 in a manner that allows it to move in the vertical direction with a small stroke. The support shaft is subjected to an upward force by a spring (elastic member) (not shown). A limit switch (sensor) 56 is disposed below one end of the support shaft 55.

[0054] In this structure, when the article 5 is placed on the belt 48 near the front end of the guide 31, the driven roller 47 is pushed downward by the article 5. As a result, the support shaft 55 of the driven roller 47 moves downward and pushes the limit switch 56. Therefore, it is possible to detect that the article 5 has been received by the guide 31.

[0055] It can also replace the limit switch 56 and use a sensor of any structure. For example, it can be a structure that uses a light sensor to detect the displacement of the support shaft 55.

[0056] Secondly, refer to Figure 4 The structure of depth D used to automatically acquire item 5 is explained. Figure 4 This is a functional block diagram showing the electrical structure of robot 1.

[0057] The robot body 10 and the robot hand 20 are electrically connected to the controller 60. The controller 60 enables the robot body 10 and the robot hand 20 to perform prescribed actions.

[0058] The motor 44 of the pull-out device 34 included in the robot hand 20 is electrically connected to the controller 60. The camera 36, ​​the first position sensor 57, the second position sensor 58, and the limit switch 56 included in the robot hand 20 are electrically connected to the controller 60.

[0059] A solenoid valve (not shown) is installed along the path connecting the adsorption unit 33 and the negative pressure source. A solenoid valve (not shown) is also installed along the path connecting the cylinder 35 and the compressed air source. These solenoid valves are electrically connected to the controller 60.

[0060] The controller 60 includes a control unit 61 and a dimension acquisition unit 62.

[0061] Specifically, the controller 60 stores a program for implementing the article size acquisition method of the present invention in its storage device. This program enables the controller 60 to function as both a control unit 61 and a size acquisition unit 62.

[0062] The control unit 61 outputs control signals to the robot body 10 and the robot arm 20. As will be explained later, the pull-out device 34 of the robot arm 20 and the robot body 10 can pull the item 5 forward. Therefore, the pull-out device 34 and the robot body 10 constitute the pull-out mechanism (pull-out section) 70.

[0063] The size acquisition unit 62 acquires the depth D of the item 5 based on the timing when the limit switch 56 is pushed.

[0064] Secondly, the action of robot 1 in acquiring the depth D of item 5 is described in detail.

[0065] exist Figure 5 In the diagram, the item located below the pulled-out object 5 is marked with the symbol 5b. The lower item (support) 5b supports the pulled-out object 5 from below. Since multiple items 5 are neatly stacked, the front side of item 5 is aligned with the front side of the lower item 5b.

[0066] First, such as Figure 2 As shown, the robot hand 20 is positioned such that the suction part 33 moves towards the front end of the guide part 31. As a result, the suction pad 43 is positioned inwards compared to the front end of the guide part 31. The robot hand 20 maintains the aforementioned basic posture. Furthermore, the posture of the robot hand 20 is adjusted so that the length direction of the guide part 31 is parallel to the depth D of the item 5.

[0067] Next, negative pressure is applied to the suction pad 43. In this state, while moving the robot body 10 and maintaining the posture of the robot hand 20, the suction part 33 is brought close to the front side of the object 5 that is being acquired at depth D.

[0068] The position of the robot hand 20 when adsorbing the item 5 using the adsorption part 33 is controlled at an appropriate height. As a result, the upper surface of the guide part 31 (in other words, the upper surface of the band 48) is lower than the lower end of the face of the item 5 at depth D.

[0069] Then, as Figure 5 As shown in state SA1, the adsorption pad 43 contacts the front side of the item 5 and adsorbs onto that surface. The controller 60 can determine the completion of adsorption by the output of an appropriate sensor (not shown). For example, a pressure sensor for negative pressure can be used as such a sensor.

[0070] Upon detection of completed adsorption, the controller 60 immediately stops the movement of the robot body 10. Next, without changing the position or posture of the robot hand 20, the controller 60 drives the pull-out device 34, causing the adsorption unit 33 to move closer to the mounting base 30. As a result, as... Figure 5 As shown in state SA2, item 5 is pulled forward while it is placed on the lower side as item 5b. The upper surface of the guide 31 of the robot hand 20 is lower than the lower surface of item 5. Therefore, when part of item 5 is pulled out, the lower surface of item 5 does not contact the guide 31.

[0071] When item 5 is fully pulled out, as Figure 5 As shown in state SA3, the state where item 5 is placed on the lower item 5b is released. In other words, item 5 leaves the upper surface of the lower item 5b. At the instant item 5 is fully pulled out, item 5 changes from a double-arm supported state to a cantilever supported state.

[0072] Since the support of the lower item 5b for item 5 is lost, the entire weight of item 5 acts on the suction part 33. Because the suction pad 43 is deformable, gravity causes item 5 to drop slightly, tilting it with its inner side facing down. As a result, the lower surface of item 5 contacts the guide part 31 (specifically, the portion of the driven roller 47 in the belt 48) and pushes downwards, thus actuating the limit switch 56. In this way, the limit switch 56 can detect that item 5 is no longer positioned above the lower item 5b.

[0073] While monitoring the state of the limit switch 56, the control unit 61 of the controller 60 pulls out the item 5 via the pull-out device 34. When the limit switch 56 detects the item 5, the size acquisition unit 62 of the controller 60 starts pulling out the item 5. Figure 5 Between the moment of state SA1 and the moment of state SA3 when the limit switch 56 detects that the item 5 has detached from the upper surface of the item 5b below, the depth D of the item 5 will be determined by the stroke of the suction part 33 sliding by the pull-out device 34.

[0074] Figure 6 An example with a relatively large depth D of the item is shown. In this example, even when the item 5 is pulled out by the pull-out device 34... Figure 6 When SB1 is pulled out to the limit of sliding movement of the adsorption part 33, such as... Figure 6 As shown in state SB2, item 5 is still supported by item 5b below. At this time, controller 60 pulls item 5 and robot arm 20 out together via robot body 10. Finally, as... Figure 6 As shown in state SB3, limit switch 56 detects item 5. At this time, the depth D of item 5 becomes the sum of the pulling distance of item 5 by pull-out device 34 and the pulling distance of item 5 by robot body 10.

[0075] The above structure allows for the appropriate acquisition of depth D, which is difficult to determine using camera 36. Therefore, further automation of the unpacking operation is possible. Since depth D can be acquired during the pulling-out of item 5, the efficiency reduction of item 5 removal can be prevented.

[0076] The depth D obtained using this method is applicable to items 5 stacked on the ground of container 6, starting from the second item from the bottom. Depth D cannot be obtained for the bottom item 5. However, for items 5 stacked vertically, the depth D is equal. If this is known beforehand, only the depth D of the top item 5 needs to be obtained. If the depth D information can be obtained in advance, the unpacking cycle time can be shortened by minimizing the distance required to pull the item 5 to the front.

[0077] When the controller 60 acquires depth D in parallel with the removal of item 5, it controls the speed at which item 5 is pulled forward to a lower speed compared to when item 5 is removed alone. Therefore, depth D can be acquired with good accuracy. Although the cycle time for removing item 5 increases when acquiring depth D, the overall operation time can be shortened by acquiring depth D only for a portion of the multiple items 5 in the unpacking process.

[0078] Secondly, refer to Figure 7 The flowchart illustrates the processing performed by controller 60 for obtaining depth D.

[0079] Initially, the control unit 61 of the controller 60 drives the pull-out device 34 of the robot hand 20 to pre-slide the suction part 33 to the innermost side (step S101). The first position sensor 57 can determine whether the suction part 33 has moved to the innermost side.

[0080] Next, the control unit 61 moves the robot hand 20 inward through the robot body 10, so that the adsorption unit 33 adsorbs the front side of the item 5 (step S102).

[0081] When the adsorption part 33 is adsorbed by the item 5, the control part 61 slides the adsorption part 33 a small distance towards the front via the pull-out device 34 (step S103). Subsequently, the item 5 also moves towards the front.

[0082] Next, the control unit 61 investigates the state of the limit switch 56 (step S104). When the limit switch 56 is pushed, the dimension acquisition unit 62 of the controller 60 calculates the depth D of the item 5 by accumulating the distance moved by the item 5 in step S103 (step S105).

[0083] When the limit switch 56 is not pushed, the control unit 61 determines whether the suction unit 33 is at the end of its sliding travel (step S106). This determination can be made using the second position sensor 58. When the suction unit 33 has not reached the limit of its sliding travel, the process returns to step S103. By repeating the processes of steps S103, S104, and S106, the item 5 can be pulled out while monitoring the state of the limit switch 56.

[0084] When the adsorption unit 33 reaches the limit of its sliding movement, the control unit 61 moves the robot hand 20 a small distance towards the front via the robot body 10 (step S107). Subsequently, the item 5 also moves towards the front.

[0085] Next, the control unit 61 investigates the state of the limit switch 56 (step S108). When the limit switch 56 is pushed, the dimension acquisition unit 62 of the controller 60 calculates the depth D of the item 5 by accumulating the distance moved by the item 5 using steps S103 and S107 (step S105). When the limit switch 56 is not pushed, the process returns to step S107. By repeating the processes of steps S107 and S108, the item 5 can be pulled out while monitoring the state of the limit switch 56.

[0086] As described above, the robot 1 of this embodiment includes an adsorption unit 33, a pull-out mechanism 70, a limit switch 56, and a size acquisition unit 62. The adsorption unit 33 is capable of holding the item 5 placed on the item 5b. The pull-out mechanism 70 is capable of pulling the adsorption unit 33 forward. The limit switch 56 detects that the item 5 is no longer on the lower item 5b because it has been pulled out. The size acquisition unit 62 acquires the size, or depth D, of the item 5 in the pull-out direction based on the distance the item 5 has been pulled out from the moment the pull-out mechanism 70 begins to pull out the item 5 until the limit switch 56 detects that the item 5 is no longer on the lower item 5b.

[0087] Therefore, during the process of pulling out item 5, the depth D of item 5 can be obtained based on the timing when the support of item 5b on the lower side of item 5 is lost.

[0088] Furthermore, in this embodiment, the robot 1 begins to pull out the item 5 when the front side of the item 5 and the front side of the item 5b below it are aligned.

[0089] Therefore, the size acquisition unit 62 can obtain the depth D of the item 5 using simple calculations.

[0090] Furthermore, the robot in this embodiment includes a robot body 10 and a robot hand 20. The robot hand 20 is mounted on the front end of the robot body 10. A limit switch 56 is disposed on the robot hand 20.

[0091] Therefore, the robot hand 20 can be used to obtain the depth D of item 5.

[0092] Furthermore, the robot 1 in this embodiment includes a robot body 10 and a controller 60 for controlling the robot hand 20. The robot hand 20 includes a guide section 31, which is capable of placing an item 5 that is no longer located above the item 5b on its lower side. The controller 60 controls the pulling mechanism 70 to pull out the item 5 when the upper surface of the guide section 31 is lower than the lower end of the front side of the item 5.

[0093] Therefore, when the item 5 is placed on top of the lower item 5b, the item 5 can be prevented from contacting the guide part 31.

[0094] Furthermore, in the robot 1 of this embodiment, the limit switch 56 is disposed on the guide section 31.

[0095] Therefore, the limit switch 56 can detect when the item 5 is no longer above the item 5b below but is placed on the guide 31.

[0096] Furthermore, in the robot 1 of this embodiment, the limit switch 56 detects that the item 5 is no longer located above the item 5b below.

[0097] Therefore, a simple structure for obtaining depth D can be implemented.

[0098] Furthermore, in the robot of this embodiment, the adsorption part 33 is disposed on the robot hand 20 mounted at the front end of the robot body 10. The pull-out mechanism 70 includes a pull-out device 34 disposed on the robot hand 20, which causes the adsorption part 33 to slide.

[0099] Therefore, the robot arm 20 can pull out the item 5 while simultaneously obtaining the depth D.

[0100] Furthermore, in the robot 1 of this embodiment, even if the pull-out device 34 moves the suction part 33 to the limit of the sliding movement, and the limit switch 56 does not detect that the item 5 is no longer located on the lower item 5b, the robot body 10 further pulls out the item 5 together with the robot hand 20 until the limit switch 56 detects it.

[0101] Therefore, even when the depth D of item 5 is large, the depth D can be measured appropriately.

[0102] Furthermore, in this embodiment, the size of the item 5 is obtained as follows: The item size acquisition method includes a pull-out step, a detection step, and an acquisition step. In the pull-out step, the item 5, which is placed on the lower item 5b and has its front surface aligned with the item 5b, is pulled forward by at least one of the robot body 10 and the robot hand 20. In the detection step, a limit switch 56 detects that the item 5 is no longer on the lower item 5b due to being pulled out. In the acquisition step, the size of the pull-out direction, i.e., the depth D, of the item 5 is obtained based on the distance the item 5 has been pulled out from the start of the pull-out step until the time when the condition that the item 5 is no longer on the lower item 5b is detected.

[0103] Therefore, during the process of pulling out item 5, the depth D of item 5 can be obtained based on the timing when the support of item 5b on the lower side of item 5 is lost.

[0104] The preferred embodiments of the present invention have been described above, and the above structure can be modified, for example, as follows.

[0105] In the described embodiment, such as Figure 5 State SA1 and Figure 6 As shown in state SB1, when the front face of item 5 and the front face of the lower item 5b are aligned, the pulling out of item 5 begins. However, even if the front faces are not aligned, if a deviation occurs in the pulling direction, the dimension acquisition unit 62 can acquire the depth D of item 5 if the amount of deviation is known. For the depth D of item 5, a degree of tolerance for error can also be considered. In this case, the front face of item 5 can be somewhat aligned with the front face of the lower item 5b, rather than being perfectly aligned.

[0106] A strain gauge (strain sensor) can be installed in the guide section 31, for example, instead of the limit switch 56. The strain gauge detects the deformation of the guide section 31 caused by the weight of the accompanying article 5. The strain gauge can also detect when the article 5 is no longer above the lower article 5b.

[0107] A force sensor can be installed at the front end of the robot body 10, replacing the limit switch 56. The force sensor detects changes in the force applied to the front end of the robot body 10, which accompanies the weight of the item 5 being supported by the cantilever of the suction unit 33. This force sensor can also detect when the item 5 is no longer positioned above the lower item 5b. In this configuration, the guide unit 31 can also be omitted from the robot hand 20.

[0108] The robotic hand 20 can also hold the item 5 by methods other than negative pressure suction. For example, it is possible to include a gripping part in the robotic hand 20 to hold the item 5.

[0109] In the robotic hand 20, the pull-out device 34 can also be used to slide the suction unit 33 by means other than driving it via the belt 48. For example, it is possible to move the sliding base 32 by means of a screw feed mechanism.

[0110] The pull-out mechanism 70 can consist of either the pull-out device 34 of the robot hand 20 or the robot body 10 alone.

[0111] Depth D can be obtained either by the same computer as controller 60 or by other computers.

[0112] The robot hand 20 can be controlled by the controller 60 of the robot body 10 or by other computers.

[0113] The support for item 5, which supports the object at depth D on its lower side, is not limited to item 5b; for example, it could be a support platform, etc. The shapes of item 5 and item 5b on its lower side can also be different.

[0114] The depth D can be measured not only with boxes, but also with other objects. Item 5b is not limited to a cuboid shape; for example, items that appear L-shaped when viewed from the side can also be used to measure the depth D.

[0115] The functions of the various elements, represented by the controller 60 disclosed in this invention, can be executed using circuitry or processing circuitry, which includes general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof configured or programmed to perform the disclosed functions. A processor, because it contains transistors and other circuitry, is considered a processing circuit or circuit. In this invention, a circuit, unit, or component is hardware that performs the listed functions or hardware programmed to perform the listed functions. The hardware can be either the hardware disclosed in this specification or other known hardware programmed or configured to perform the listed functions. When the hardware is considered a processor, a circuit, component, or unit is a combination of hardware and software, with the software used in the structure of the hardware and / or processor.

Claims

1. A robot, characterized in that: The robot includes a holding part, a pulling part, a sensor, and a size acquisition part. The holding part holds an item placed on a support. The pulling part pulls the holding part forward. The sensor detects that the item is no longer on the support because it has been pulled out. The size acquisition part obtains the size of the item in the pulling direction based on the distance the item has been pulled out from the moment it is pulled out by the pulling part until the moment the sensor detects that the item is no longer on the support. The retaining part is configured on the end effector mounted at the front end of the robot body. The pull-out portion includes a pull-out device disposed on the end effector, which causes the retaining portion to slide. Even if the pull-out device moves the holding part to the limit of sliding movement, if the sensor does not detect that the item is no longer on the support, the robot body further pulls out the item together with the end effector until the sensor detects that the item is no longer on the support.

2. The robot according to claim 1, characterized in that: With the front side of the item and the front side of the support aligned, the item is pulled out.

3. The robot according to claim 1 or 2, characterized in that: The robot includes a robot body and an end effector, the end effector being mounted on the front end of the robot body. The sensor is configured on the end effector.

4. The robot according to claim 3, characterized in that: The robot includes a controller that controls the robot body and the end effector. The end effector includes a receiving portion capable of holding the article that is no longer located on the support. The controller controls the pulling part to pull out the item while the upper surface of the receiving part is below the lower end of the front side of the item.

5. The robot according to claim 4, characterized in that: The sensor is configured in the receiving section.

6. The robot according to any one of claims 3 to 5, characterized in that: The sensor is a limit switch.

7. The robot according to any one of claims 3 to 5, characterized in that: The sensor is a strain sensor.

8. The robot according to claim 1 or 2, characterized in that: The robot includes a robot body and an end effector, the end effector being mounted on the front end of the robot body. The sensor is a force sensor located at the front end of the robot body.

9. A method for obtaining the size of an item, characterized in that: The method for obtaining the size of an item includes a pull-out step, a detection step, and an acquisition step. In the pull-out step, at least one of the robot body and the end effector pulls the item placed on the support forward. In the detection step, a sensor detects that the item is no longer on the support because it has been pulled out. In the acquisition step, the size of the item in the pull-out direction is obtained based on the distance the item has been pulled out from the start of the pull-out step to the moment the sensor detects that the item is no longer on the support. It also includes a sliding movement step in which an object placed on a support is pulled forward by the end effector. Even if the end effector is moved to the limit of the sliding movement during the sliding movement step, if the sensor does not detect that the item is no longer on the support, the robot body further pulls out the item together with the end effector until the sensor detects that the item is no longer on the support.

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