Robot hand and control device

Abstract

A pad body (111) included in a suction pad (110) of a robot hand (100) is composed of a flexible member, and an internal space (114) surrounded by an outer flexible part (112) and an inner flexible part (113) is formed therein. A suction space (117) has a larger cross-sectional area on a horizontal plane at a second position on a free end side than at a first position. When an inner support part (122) that supports a base end part of the inner flexible part (113) is moved to the free end side, the pad body (111) is capable of reducing the area of a new opening (116) formed by a free end part protruding outward.

Description

Robot Hand and Control Device

[0001] The present invention relates to a robot hand and a control device.

[0002] The suction-type robot hand can easily operate and control compared to other robot hands while ensuring the gripping force required to grip the object to be suctioned, and the time until the object is gripped is short. Therefore, it is actively adopted in various industries such as agriculture and manufacturing. On the other hand, the suction-type robot hand has a problem that it cannot grip an object smaller than the opening because the object can be suctioned by blocking the opening of the suction pad. There is a need for a new mechanism to adjust the size of the opening according to the object to be suctioned and gripped.

[0003] As an example of a robot hand with an adjustable opening of the suction pad, Non-Patent Document 1 discloses a suction-type robot hand in which a shape memory alloy is stretched around the suction pad. The robot hand of Non-Patent Document 1 can change the shape of the opening of the suction pad by adjusting the heat applied to the shape memory alloy to make the shape memory alloy into an arbitrary shape.

[0004] Although it is not a robot hand, Non-Patent Document 2 discloses a 3D (Three-Dimensional) printer with an adjustable opening at the nozzle tip. The 3D printer of Non-Patent Document 2 can change the diameter of the opening at the nozzle tip by controlling four motors and strings.

[0005] Zhenishbek Zhakypov, et al., "An Origami-Inspired Reconfigurable Suction Gripper for Picking Objects With Variable Shape and Size", [online], [searched on November 18, 2024], Internet <URL: https: / / ieeexplore.ieee.org / stamp / stamp.jsp?tp=&arnumber=<8385192>Seok Won Kang, et al., "Multiscale 3D printing via active nozzle size and shape control", [online], [searched on November 18, 2024], Internet <URL: https: / / www.science.org / doi / pdf / 10.1126 / sciadv.adn7772>

[0006] The robot hand described in Non-Patent Document 1 performs control to adjust the heat applied to the shape memory alloy stretched around the suction pad. Therefore, the mechanism, operation, and control for changing the shape of the opening of the suction pad become complicated, and there is a problem that the manufacturing cost increases. Further, the technique described in Non-Patent Document 2 controls four motors and strings. Even if it could be applied to the suction pad of a known suction-type robot hand, it has the same problem as the robot hand described in Non-Patent Document 1.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to reduce the manufacturing cost of a robot hand capable of adjusting the size of the opening of a suction pad.

[0008] To achieve the above objective, the robot hand according to the present invention includes a suction pad that includes a cylindrical pad body formed extending from a base end to a free end, wherein when an opening formed on the inside of the free end of the pad body is blocked by an object to be adsorbed, a gas suction space is formed surrounded by the blocked portion of the object and the inner wall of the pad body, and the object can be adsorbed by the gas being sucked in from a suction port formed on the inside of the base end of the pad body; a pad support portion that supports the base end of the pad body; and a gas suction portion that sucks the gas from the suction space from the suction port, wherein the pad body is made of a flexible member having flexibility, and has an internal space surrounded by an outer flexible portion as an outer wall and an inner flexible portion as an inner wall A pad support portion is formed, and the pad support portion includes an outer support portion that supports the base end of the outer flexible portion and an inner support portion that supports the base end of the inner flexible portion, and further comprises an inner moving portion that moves the inner support portion relative to the outer support portion, wherein the suction space has a larger cross-sectional area at the second position on the free end side than at the first position on the base end side, and when the inner moving portion moves the inner support portion relative to the outer support portion on the free end side, the flexible member of the pad body elastically deforms and the shape of the internal space changes, causing the free end to protrude outward, and the area of ​​the new opening formed by the protruding free end can be reduced.

[0009] According to the present invention, the robot hand can adjust the size of the opening of the suction pad by moving the inner support part relative to the outer support part using the inner moving part. As a result, the robot hand according to the present invention can adjust the size of the opening of the suction pad, but the mechanism, operation, and control for changing the shape of the opening of the suction pad is simpler than that of a robot hand that cannot reduce the cross-sectional area of ​​the opening by moving the inner support part from the base end to the free end side relative to the outer support part, thus reducing manufacturing costs.

[0010] Overall explanatory diagram of the robot hand according to Embodiment 1 Bottom view of the robot hand viewed from the direction of arrow II in Figure 1 Cross-sectional view along line III-III in Figure 2 Explanatory diagram of the main parts of the pad body in its initial state Explanatory diagram of the main parts of the pad body with the free end protruding one step Explanatory diagram of the main parts of the pad body with the free end protruding two steps Cross-sectional diagram for explaining the method of generating the pad body according to Embodiment 1 Diagram showing an overview of the experimental results of Experimental Examples 1 to 12 Diagram showing details of the experimental results of Experimental Examples 1 to 12 Explanatory diagram of Experimental Examples 21 to 24 Diagram showing the experimental results of Experimental Examples 21 to 24 Cross-sectional view of the robot hand according to Embodiment 2 Block diagram showing the functional configuration of the control device according to Embodiment 2 Block diagram showing the hardware configuration of the control device according to Embodiment 2 Flowchart of the object adsorption and movement process according to Embodiment 2 Cross-sectional view of the robot hand according to Embodiment 3 Explanatory diagram of the main parts of the pad body in its initial state Explanatory diagram of the main parts of the pad body with the free end protruding one step Block diagram showing the functional configuration of the control device according to Embodiment 3 Cross-sectional view of the robot hand according to Embodiment 4 Explanatory diagram of the main parts of the pad body in its initial state Explanatory diagram of the main parts of the pad body with the free end protruding one step

[0011] Hereinafter, a robot hand and a housing container according to embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals. Furthermore, in order to facilitate understanding of the configuration of the present invention, the X direction of the arrows shown in the drawings may be described as "forward," the -X direction as "backward," the Y direction as "left," the -Y direction as "right," the Z direction as "up," and the -Z direction as "down."

[0012] [Embodiment 1] (Regarding the robot hand 100 according to Embodiment 1) As shown in Figure 1, the robot hand 100 according to Embodiment 1 of the present invention is connected to the lower end, which is the free end of the robot arm 200. The robot hand 100 is a so-called suction-type robot hand, and for example, when it is moved downward by the robot arm 200 to a position where it can contact the object 300 to be suctioned, it is possible to suction and grasp the object 300 by sucking up gas under control from the control device 210 of the robot arm 200. As shown in Figure 3, the robot hand 100 includes a suction pad 110 as the robot hand body, a pad support part 120 that supports the suction pad 110, an inner moving part 130 that moves inside the pad support part 120, and a gas suction part 140 that sucks up gas.

[0013] The suction pad 110 includes a pad body 111 that is formed in a cylindrical shape and extends downward from the upper end, which is the base end, to the lower end, which is the free end. As shown in Figure 3, the pad body 111 is made of a flexible member made of silicone and has a cross-section that is approximately W-shaped. Specifically, the pad body 111 is made of a flexible member in which the lower end of the outer flexible portion 112, which is the outer wall, and the lower end of the inner flexible portion 113, which is the inner wall, are connected, so the cross-section is approximately W-shaped. In addition, an internal space 114 is formed inside the pad body 111, surrounded by the flexible portions 112 and 113.

[0014] Furthermore, as shown in Figures 2 and 3, in the inner portion of the pad body 111 surrounded by the inner flexible portion 113, a gas suction port 115 is formed at the upper end, which is the base end, and an opening 116 is formed at the lower end, which is the free end. Therefore, when the opening 116 is closed by the upper part of the object 300 shown in Figure 1, a gas suction space 117 is formed surrounded by the closed portion of the upper part of the object 300 and the inner wall, and when the gas in the suction space 117 is sucked in from the suction port 115 by the gas suction portion 140, the object 300 can be adsorbed.

[0015] In this embodiment, since the inner wall of the suction pad 110 is formed in a substantially conical shape, the suction space 117 is also formed in a substantially conical shape similar to the inner wall. For this reason, the cross-sectional area of ​​the suction space 117 on the horizontal plane increases as you move from the upper end, which is the base end, to the lower end, which is the free end. For example, the cross-sectional area of ​​the suction space 117 is larger at a predetermined second position lower on the free end side than at a predetermined first position upper on the base end side, and is largest at the opening 116 at the lower end, which is the free end.

[0016] Furthermore, a first annular projection 118 is formed at the lower end of the pad body 111, projecting downward and surrounding the outside of the opening 116. In addition, multiple second annular projections 119 are formed at intervals from the upper end to the lower end of the inner flexible portion 113 of the pad body 111, projecting into the suction space 117 on the horizontal plane. The first projection 118 and the second projections 119 are made of the same flexible silicone material as the pad body 111 and are elastically deformable. Therefore, when the opening 116 is closed by the upper part of the object 300, the first projection 118 can elastically deform and adhere tightly to the outer part of the closed portion of the upper part of the object 300 without any gaps.

[0017] The pad support portion 120 is a rigid member made of, for example, polylactic acid (PLA) resin. The pad support portion 120 includes an outer support portion 121 that supports the upper end of the outer flexible portion 112 and an inner support portion 122 that supports the upper end of the inner flexible portion 113. Therefore, the upper ends of the pad body 111, which are the base ends of each flexible portion 112, 113, are supported by the respective support portions 121, 122 of the pad support portion 120, while the lower ends, which are the free ends of each flexible portion 112, 113, are not supported. Furthermore, the pad body 111 does not have a member in the internal space 114 that restricts the shape of the pad body 111, unlike the shape memory alloy described in Patent Document 1. Therefore, the lower side of the pad body 111, which is the free end, can be freely reshaped without being restricted by other members of the robot hand 100. Furthermore, the inner support portion 122 has a first through-hole 123 that penetrates vertically, and the lower end of the first through-hole 123 is continuous with the suction port 115 of the pad body 111.

[0018] As shown in Figure 3, the inner moving part 130 includes a frame 131 with an outer support part 121 at its lower end, a servo motor 132 as an example of a drive motor supported by the frame 131, and a drive worm wheel gear 134 fixed to the drive shaft 133 of the servo motor 132 and rotationally driven by the rotation of the drive shaft 133 by the servo motor 132. The inner moving part 130 also includes a driven worm wheel gear 136 fixed to a driven shaft 135 rotatably supported by the frame 131, and a worm gear 137 that is held in a meshed state between the worm wheel gears 134 and 136 and extends in the vertical direction. The inner support part 122 is fixed to the lower end of the worm gear 137. The worm gear 137 also has a second through hole 138 that penetrates in the vertical direction, and the lower end of the second through hole 138 is continuous with the upper end of the first through hole 123 of the inner support part 122.

[0019] The inner moving part 130 can move the worm gear 137 downward via the worm wheel gears 134 and 136 by having the servo motor 132 rotate the drive shaft 133 in the forward direction under control from the control device 210. The inner moving part 130 can also move the worm gear 137 upward via the worm wheel gears 134 and 136 by having the servo motor 132 rotate the drive shaft 133 in the reverse direction. Therefore, by moving the worm gear 137 in the vertical direction, the inner moving part 130 can move the inner support part 122 fixed to the lower end of the worm gear 137 in the vertical direction as a whole.

[0020] The gas suction unit 140 includes, for example, a vacuum pump (not shown), and a suction tube 141 that extends through the through holes 123 and 138 to the suction port 115. The gas suction unit 140 drives the pump motor of the vacuum pump by control from the control device 210 to discharge the air, which is the gas in the container of the vacuum pump, and maintains the inside of the container at a low pressure below atmospheric pressure, i.e., a vacuum, thereby drawing the air, which is the gas in the suction space 117, into the container via the suction tube 141 that extends to the suction port 115.

[0021] (Regarding the change in shape of the pad body 111 according to Embodiment 1) In this embodiment, when the robot hand 100 drives the servo motor 132 by control from the control device 210 to rotate the drive shaft 133 in the forward direction by a predetermined amount of rotation, the inner support portion 122 moves downward, and the free end of the pad body 111 is pushed out one step from the initial state shown in Figure 4A to the state shown in Figure 4B, where it protrudes. In this case, the area of ​​the new opening 116 shown in Figure 4B is one step smaller than the area of ​​the opening 116 shown in Figure 4A. Also, in this case, at the new free end of the pad body 111 that has been pushed out one step and protruded as shown in Figure 4B, the second protruding portion 119, which is located at the lowest point, surrounds the outside of the new opening 116 and protrudes downward.

[0022] Furthermore, when the robot hand 100 rotates the drive shaft 133 by a predetermined amount of rotation under control from the control device 210, the inner support portion 122 moves further downward, and the free end of the pad body 111 is pushed out one more step from the state shown in Figure 4B to the state shown in Figure 4C. In this case, the area of ​​the new opening 116 shown in Figure 4C is one step smaller than the area of ​​the opening 116 shown in Figure 4B. Also, in this case, at the new free end of the pad body 111 that has been pushed out two steps and protruded as shown in Figure 4C, the second protruding portion 119, which is positioned second from the bottom, surrounds the outside of the new opening 116 and protrudes downward.

[0023] Although not shown in the diagram, each time the robot hand 100 rotates the drive shaft 133 in the forward direction by a predetermined amount of rotation, the inner support portion 122 moves further downward, and the free end of the pad body 111 is pushed out in three, four, ... stages from the state shown in Figure 4C, and protrudes further. As a result, the area of ​​the new opening 116 decreases by one stage each time the free end of the pad body 111 is pushed out in three, four, ... stages, and at the new free end, the second protruding portions 119, which are positioned third, fourth, ... from the bottom, surround the outside of the new opening 116 and protrude downward.

[0024] On the other hand, each time the robot hand 100 rotates the drive shaft 133 in the reverse direction by a predetermined amount of rotation, the inner support portion 122 moves upward, pulling back the free end of the pad body 111, returning to the state shown in Figure 4C, the state shown in Figure 4B, and the initial state shown in Figure 4A. As a result, the area of ​​the new opening 116 increases by one step each time the free end of the pad body 111 is pulled back, and at the new free end, the second protrusion 119 and the first protrusion 118, which are positioned second and first from the bottom, protrude downward, surrounding the outside of the new opening 116 in that order.

[0025] (Regarding the method for producing the pad body 111 according to Embodiment 1) In this embodiment, as shown in Figure 5, the pad body 111 is produced using a mold 400 and an inner support part 122, which have a shape in which a substantially cone at the top and a lower cylinder extending downward with a circle having substantially the same diameter as the bottom surface of the cone as the upper surface are connected. Multiple annular grooves 410 are formed in the upper conical portion of the mold 400 at predetermined intervals.

[0026] First, as shown by the dotted line in Figure 5, the manufacturer pours liquid silicone, an example of a liquid flexible material, from above the mold 400 and allows the silicone to solidify on top of the mold 400. Next, after the silicone has solidified, the manufacturer places the inner support portion 122 on the upper surface of the mold 400 and pours liquid silicone again from above the inner support portion 122 and the mold 400 to solidify. It is preferable that the thickness of the solidified silicone be 3 mm or more in order for the pad body 111 to maintain the required strength. Then, after peeling the solidified silicone from the mold 400, the manufacturer generates the pad body 111 by rolling up the lower cylindrical portion of the silicone. At this time, the inner support portion 122 is integral with the pad body 111, and the protrusions 118 and 119 are integrally formed with the pad body 111.

[0027] As described above, according to the robot hand 100 of this embodiment, the suction pad 110 includes a cylindrical pad body 111 that extends from the upper end, which is the base end, to the lower end, which is the free end, with the upper end being supported by the pad support portion 120. Furthermore, when the opening 116 formed on the inside of the lower end, which is the free end, of the pad body 111 is blocked by the object 300 to be adsorbed, a gas suction space 117 is formed surrounded by the blocked portion of the object 300 and the inner wall of the pad body 111. Therefore, the suction pad 110 is able to adsorb the object 300 by drawing air, which is a gas, from the suction port 115 formed on the inside of the base end of the pad body 111 by the gas suction portion 140.

[0028] Furthermore, the pad body 111 is made of a flexible material and has an internal space 114 formed inside, surrounded by an outer flexible portion 112 as an outer wall and an inner flexible portion 113 as an inner wall. The pad support portion 120 includes an outer support portion 121 that supports the base end of the outer flexible portion 112 and an inner support portion 122 that supports the base end of the inner flexible portion 113, and the inner moving portion 130 moves the inner support portion 122 in the vertical direction, which is the extension direction of the pad body 111, relative to the outer support portion 121. In addition, the suction space 117 has a larger cross-sectional area on the horizontal plane at the second position on the free end side than at the first position on the base end side. Furthermore, when the inner movable part 130 of the pad body 111 moves the inner support part 122 downward toward the free end side relative to the outer support part 121, the flexible member elastically deforms and the shape of the internal space 114 changes, causing the lower end, which is the free end, to be pushed outward and downward and protrude, thereby reducing the area of ​​the new opening 116 formed by the free end that protrudes downward.

[0029] In this way, the robot hand 100 can adjust the size of the opening 116 of the suction pad 110 by having the inner moving part 130 move the inner support part 122 relative to the outer support part 121. As a result, the robot hand 100 according to this embodiment can adjust the size of the opening of the suction pad, but the mechanism, operation, and control for changing the shape of the opening 116 of the suction pad 110 is simpler than that of a robot hand that can adjust the size of the opening of the suction pad but cannot reduce the area of ​​the new opening formed by moving the inner support part toward the free end relative to the outer support part, thus reducing manufacturing costs.

[0030] Here, for example, the robot hand described in Non-Patent Document 1 and the robot hand to which the technology described in Non-Patent Document 2 is applied have more complex mechanisms, operations, and controls than conventionally known suction-type robot hands, so the advantage of suction-type robot hands, which is that they have a shorter time to grasp an object than other robot hands, that is, a faster speed to grip an object, is lost. In contrast, the robot hand 100 according to this embodiment can adjust the size of the opening 116 of the suction pad 110 simply by the inner moving part 130 moving the inner support part 122, so the mechanism, operation, and control are simpler than the robot hand described in Non-Patent Document 1 and the robot hand to which the technology described in Non-Patent Document 2 is applied, so the time to grasp the object 300 is less likely to be long and the speed to grip the object 300 is less likely to be slow.

[0031] Furthermore, for example, the robot hand described in Non-Patent Document 1 uses a shape memory alloy that changes shape in response to temperature changes, so there is a risk that it may not be able to change to the desired shape due to the influence of the temperature of the external environment. In contrast, the robot hand 100 according to this embodiment has a pad body 111 made of a flexible material such as silicon, so the deformation of the pad body 111 is less susceptible to adverse effects from the temperature of the external environment than that of a shape memory alloy. As a result, the robot hand 100 according to this embodiment can reduce the adjustment of the size of the opening 116 of the suction pad 110 due to changes in the temperature of the external environment compared to the robot hand described in Non-Patent Document 1.

[0032] Furthermore, in the robot hand 100 according to this embodiment, the suction space 117 has a cross-sectional area that increases as it moves from the upper end, which is the base end, to the lower end, which is the free end. And in the pad body 111, the area of ​​the new opening decreases as the inner support portion 122 moves from the upper end, which is the base end, to the lower end, which is the free end. In this way, the robot hand 100 according to this embodiment can reduce the area of ​​the opening 116 of the suction pad 110 as the inner moving portion 130 moves the inner support portion 122 downward from the upper end.

[0033] Furthermore, according to the robot hand 100 of this embodiment, the pad body 111 includes a first projection 118 formed to protrude outward from the free end and surround the outside of the opening 116. The pad body 111 also includes a second projection 119 formed to protrude from the inner flexible portion 113 toward the suction space 117, and protrudes outward from the new free end that is pushed out and protrudes when the inner moving portion 130 moves the inner support portion 122 downward toward the free end, and surrounds the outside of the new opening 116. The first projection 118 and the second projection 119 are flexible and can adhere closely to the object 300 without any gaps.

[0034] In this way, the robot hand 100 can more easily pick up and grasp the object 300 with the suction pad 110 when the area of ​​the opening 116 does not need to be smaller than that of a robot hand whose pad body does not include the first protrusion. Also, in this way, the robot hand 100 can more easily pick up and grasp the object 300 with the suction pad 110 when the area of ​​the opening 116 needs to be smaller than that of a robot hand whose pad body does not include the second protrusion. As a result, the robot hand 100 according to this embodiment can more easily pick up and grasp the object 300 with the suction pad 110, regardless of whether or not it is necessary to reduce the area of ​​the opening 116. Also, in this way, the robot hand 100 according to this embodiment can adjust the area of ​​the opening 116 in stages according to the number of each protrusion 118, 119.

[0035] [Experimental Examples Regarding Graspable Objects 300] Here, the inventor conducted an experiment to determine whether the robot hand 100 according to this embodiment could actually adsorb and grasp various objects 300.

[0036] [Experimental Example 1] In Experimental Example 1, the suction pad 110 and gas suction unit 140 of the robot hand 100 according to this embodiment were used to confirm whether a PET bottle containing water and weighing approximately 500 g could be suctioned and grasped on the top surface of its cap with an outer diameter of φ28 (=28 [mm]) as the object to be suctioned 300. In Experimental Example 1, the outer diameter of the circular opening 116 of the suction pad 110 of the robot hand 100 was set to φ55 (=55 [mm]), φ45 (=45 [mm]), φ35 (=35 [mm]), and φ25 (=25 [mm]) to confirm whether the top surface of the PET bottle cap could be grasped in each case.

[0037] [Experimental Example 2] In Experimental Example 2, the same verification was performed as in Experimental Example 1, except that the position where the suction pad 110 adheres was set to the side of the bottle in the center of the PET bottle body, which has an outer diameter of φ55 (= 55 [mm]) and a length of approximately 150 mm.

[0038] [Experimental Example 3] In Experimental Example 3, the object to be adsorbed, 300, was a beverage can with a total weight of approximately 355 g, and the position where the adsorption pad 110 adsorbed was the top surface of the can with a diameter of approximately φ52 (= 52 [mm]), except that the verification was the same as in Experimental Examples 1 and 2.

[0039] [Experimental Example 4] In Experimental Example 4, the same verification was performed as in Experimental Examples 1 to 3, except that the position where the suction pad 110 adheres was set to the side of a can with an outer diameter of φ52 (= 52 [mm]) and a length of approximately 155 mm.

[0040] [Experimental Example 5] In Experimental Example 5, the object to be adsorbed, 300, was a tomato with a total weight of approximately 335 g, and the adsorption pad 110 was positioned on the side of the tomato with an outer diameter of approximately φ70 (= 70 [mm]). The same verification was performed as in Experimental Examples 1 to 4.

[0041] [Experimental Example 6] In Experimental Example 6, the object to be adsorbed, 300, was a package containing two tomatoes with a total weight of approximately 680 g, a maximum width and thickness of approximately 70 mm, and a length of approximately 150 mm. The same verification was performed as in Experimental Examples 1 to 5, except that the position where the adsorption pad 110 adsorbed was the side of one of the tomatoes covered by the film.

[0042] [Experimental Example 7] In Experimental Example 7, the object 300 to be adsorbed was a 540 g beverage pack containing a milk beverage, and the position where the adsorption pad 110 adsorbed was an inclined surface with a vertical length of 40 mm and a horizontal length of 70 mm at the upper part of the beverage pack. The same confirmation as in Experimental Examples 1 to 6 was performed except for this.

[0043] [Experimental Example 8] In Experimental Example 8, the position where the adsorption pad 110 adsorbed was a side surface part with a vertical length of 105 mm and a horizontal length of 70 mm of the beverage pack. The same confirmation as in Experimental Examples 1 to 7 was performed except for this.

[0044] [Experimental Example 9] In Experimental Example 9, the object 300 to be adsorbed was a plastic packaging pack with a width of about 115 mm, a length of about 160 mm, a thickness of about 90 mm, and a total weight of about 478 g, containing a bunch of grapes, and the position where the adsorption pad 110 adsorbed was the upper surface of the pack. The same confirmation as in Experimental Examples 1 to 8 was performed except for this.

[0045] [Experimental Example 10] In Experimental Example 10, the object 300 to be adsorbed was a vacuum pack with a width of about 130 mm, a length of about 160 mm, a maximum thickness of about 30 mm, and a total weight of about 129 g, containing salad chicken, and the position where the adsorption pad 110 adsorbed was the upper surface of the pack. The same confirmation as in Experimental Examples 1 to 9 was performed except for this.

[0046] [Experimental Example 11] In Experimental Example 11, the object 300 to be adsorbed was a 1-yen coin with a total weight of 1 g, an outer diameter of φ20 (= 20 [mm]), and a thickness of 1.5 mm, and the position where the adsorption pad 110 adsorbed was the upper surface of the 1-yen coin. The same confirmation as in Experimental Examples 1 to 10 was performed except for this.

[0047] [Experimental Example 12] In Experimental Example 12, the object 300 to be adsorbed was a banana with a total weight of 130 g, an outer diameter of φ40 (= 40 [mm]), and a length of 200 mm, and the position where the adsorption pad 110 adsorbed was the side surface of the banana. The same confirmation as in Experimental Examples 1 to 11 was performed except for this.

[0048] [Experimental Results of Experimental Examples Regarding the Grippable Object 300] As a result of the experiment, as shown in FIG. 6, in all of Experimental Examples 1 to 12, the adsorption and gripping of the object 300 were successful.

[0049] Specifically, as shown in Figure 7, in Experimental Example 1, successful suction and gripping of PET bottles was achieved when the outer diameter of the opening 116 was φ25, and in Experimental Example 2, when the outer diameter of the opening 116 was φ55, φ45, and φ35. In Experimental Example 3, successful suction and gripping of cans was achieved when the outer diameter of the opening 116 was φ55 and φ45, and in Experimental Example 4, when the outer diameter of the opening 116 was φ35 and φ25. In Experimental Example 5, successful suction and gripping of tomatoes and tomato packaging was achieved for all outer diameters of the opening 116: φ55, φ45, φ35, and φ25, and in Experimental Example 6, successful suction and gripping of tomatoes and tomato packaging was achieved for φ55, φ45, and φ35.

[0050] Furthermore, in Experimental Example 7, when the outer diameter of the opening 116 was φ55 and φ45, and in Experimental Example 8, when the outer diameter was φ55, φ45, φ35, and φ25, successful suction and gripping of beverage packs were achieved. In Experimental Example 9, when the outer diameter of the opening 116 was φ55 and φ45, successful suction and gripping of plastic packaging packs were achieved, and in Experimental Example 10, when the outer diameter was φ35 and φ25, successful suction and gripping of vacuum packs were achieved. In Experimental Example 11, when the outer diameter of the opening 116 was φ25, successful suction and gripping of a 1-yen coin was achieved, and in Experimental Example 12, when the outer diameter was φ35 and φ25, successful suction and gripping of a banana were achieved.

[0051] These results show that, regardless of the shape of the object 300's suction surface (flat, curved, spherical, etc.) or whether the suction surface is uneven, the robot hand 100 according to this embodiment can suction and grasp the object 300 if the outer diameter of the opening 116 is adjusted so that the protrusions 118 and 119 are in close contact with the suction surface and the gap between the pad body 111 and the object 300 is filled. Furthermore, as shown in Experimental Example 11, the robot hand 100 according to this embodiment can suction and grasp an object 300 even if its suction surface is smaller than the outer diameter of the opening 116, as long as the gap between the pad body 111 and the object 300 is filled.

[0052] [Experimental example regarding the gripping force of the robot hand 100] The inventor also conducted an experiment to measure how much force the robot hand 100 according to this embodiment can actually use to attract and grip an object 300.

[0053] [Experimental Examples 21-24] As shown in Figure 8, in Experimental Examples 21-24, first, the suction pad 110 and suction tube 141 of the robot hand 100 according to this embodiment were fixed to a vertically movable stage provided at the top of the tensile testing machine, and a force gauge was fixed to the bottom of the tensile testing machine, with a horizontal acrylic plate measuring 70 mm in length and width placed on the upper end of the force gauge. Then, in Experimental Examples 21-24, with the upper surface of the acrylic plate attached to the suction pad 110, the movable stage was moved upward at a speed of 3 mm / s to pull up the robot hand 100, and the maximum tensile load [N] until the suction and gripping of the robot hand 100 on the acrylic plate was released was measured with the force gauge.

[0054] In Experimental Examples 21 to 24, the outer diameter of the opening 116 was set to φ55 (Experimental Example 21), φ45 (Experimental Example 22), φ35 (Experimental Example 23), and φ25 (Experimental Example 24). The vacuum pump of the gas suction section 140 (not shown) was controlled so that the pressure in the suction space 117, i.e., the negative pressure, when the robot hand 100 adsorbed the acrylic plate was approximately 70 kPa. In Experimental Examples 21 to 24, a force gauge manufactured by Imada Corporation was used.

[0055] [Experimental Results of Experimental Examples Regarding the Gripping Force of the Robot Hand 100] The results of the experiment are shown in the graph in Figure 9. In the graph in Figure 9, the vertical axis represents the tensile load value [N] displayed on the force gauge, and the horizontal axis represents the time [s] from the start of upward movement of the moving stage. As shown in Figure 9, in experimental examples 21, 22, 23, and 24, the tensile load reached its maximum value approximately 9 seconds, 9 seconds, 10 seconds, and 3.5 seconds after the start of movement of the moving stage, with measured values ​​of approximately 49 [N] (experimental example 21, see solid line), approximately 46 [N] (experimental example 22, see dashed line), approximately 43 [N] (experimental example 23, see double dashed line), and approximately 18 [N] (experimental example 24, see dashed line).

[0056] These results show that the robot hand 100 according to this embodiment exhibits a tensile load magnitude, i.e., suction force, suction force, and gripping force, that increases with the size of the outer diameter and area of ​​the opening 116. Furthermore, it can be seen that the robot hand 100 according to this embodiment can obtain a gripping force of 18N or more, sufficient to grip an object 300, if the outer diameter of the opening 116 is φ25 or more.

[0057] Furthermore, the rate of increase in the maximum tensile load when the outer diameter of the opening 116 increases by φ10 is 58% (43 - 18 / 43 ≈ 0.581) from experimental example 24 (φ25) to experimental example 23 (φ35), which is greater than the 6.5% (46 - 43 / 46 ≈ 0.0652) from experimental example 23 (φ35) to experimental example 22 (φ45) and the 6.1% (49 - 46 / 49 ≈ 0.0612) from experimental example 22 (φ45) to experimental example 21 (φ55). This is thought to be due to the fact that as the suction space 117 and the opening 116 increase in size, the rate of reduction of these spaces due to air suction in the suction space 117 increases. Therefore, in order to prevent the rate of increase in gripping force from decreasing even if the suction space 117 and opening 116 are enlarged, it is preferable to minimize the length of the pad body 111 in the vertical direction, which is the extension direction, in order to reduce the adverse effects of negative pressure.

[0058] [Embodiment 2] In Embodiment 1, the control device 210 controls the drive of the servo motor 132 of the inner moving part 130 and controls the output of the vacuum pump of the gas suction part 140, but the control of the robot hand 100 by the control device 210 is not limited to this. For example, the control device 210 may control the robot hand 100 based on inputs from various parts attached to the robot hand 100 or robot arm 200. Hereinafter, the robot hand 100 and control device 210 according to Embodiment 2 will be described in detail with reference to Figures 10 to 13. Note that in Embodiment 2, a configuration different from Embodiment 1 will be described, and the same configuration as in Embodiment 1 will be omitted from the description as it is redundant.

[0059] (Regarding the robot hand 100 according to Embodiment 2) As shown in Figure 10, the robot hand 100 according to Embodiment 2 of the present invention further includes a negative pressure sensor 150 as an example of a first pressure detection unit for detecting the pressure in the suction space 117, and a camera 160 as an example of an imaging unit.

[0060] The negative pressure sensor 150 is attached, for example, to the suction tube 141 of the gas suction unit 140, and detects the pressure in the suction space 117 by detecting the pressure in the suction tube 141. For example, the negative pressure sensor 150 detects that the suction space 117 is under negative pressure when the pressure in the suction space 117 becomes a negative value when gas is drawn into the suction space 117 by the gas suction unit 140.

[0061] The camera 160 is attached, for example, to the outer flexible portion 112 of the suction pad 110 and captures images of the object 300 to be sucked, which is located below the suction pad 110.

[0062] (Regarding the control device 210 according to Embodiment 2) The control device 210 is a computer device such as a microcontroller board, a PC (Personal Computer), or a server computer. As shown in Figure 11, the control device 210 includes an arm control unit 211 that controls the robot arm 200 and a hand control unit 212 that controls the robot hand 100. The hand control unit 212 includes a movement control unit 213 that controls the movement of the inner support unit 122, a suction control unit 214 that controls the suction of gas, an area calculation unit 215 that calculates the area of ​​the opening 116 capable of adsorbing an object 300, and an adsorption determination unit 216 that determines whether or not the adsorption pad 110 is adsorbing an object 300.

[0063] (Hardware configuration of the control device 210 according to Embodiment 2) As shown in Figure 12, the control device 210 includes a control unit 51 that executes processing according to a control program 59. The control unit 51 includes a CPU (Central Processing Unit). The control unit 51 functions according to the control program 59 as the arm control unit 211, hand control unit 212, movement control unit 213, suction control unit 214, area calculation unit 215, and suction determination unit 216 shown in Figure 11.

[0064] Returning to Figure 12, the control device 210 includes a main memory unit 52 that loads the control program 59 and is used as a work area for the control unit 51. The main memory unit 52 includes RAM (Random Access Memory).

[0065] Furthermore, the control device 210 includes an external storage unit 53 that pre-stores a control program 59. The external storage unit 53 supplies the data to be stored in this program to the control unit 51 according to the instructions of the control unit 51, and stores the data supplied from the control unit 51. The external storage unit 53 includes non-volatile memory such as flash memory, HDD (Hard Disk Drive), or SSD (Solid State Drive).

[0066] Furthermore, the control device 210 includes an operation unit 54 that is operated by the user. Information input via the operation unit 54 is supplied to the control unit 51. The operation unit 54 includes information input components such as a keyboard, mouse, or touch panel.

[0067] Furthermore, the control device 210 includes a display unit 55 that displays information input via the operation unit 54 and information output by the control unit 51. The display unit 55 includes a display device such as an LCD (Liquid Crystal Display) or an organic EL (Electro-Luminescence) display.

[0068] Furthermore, the control device 210 includes a transmitting and receiving unit 56 for sending and receiving information. The transmitting and receiving unit 56 includes information and communication components such as a network termination device and a wireless communication device that connect to a network.

[0069] Furthermore, in the control device 210, the main memory unit 52, external memory unit 53, operation unit 54, display unit 55, and transmission / reception unit 56 are all connected to the control unit 51 via the internal bus 60.

[0070] The control device 210 realizes the functions of each of the above-mentioned parts 211 to 216 shown in Figure 11 by having the control unit 51 use the main memory unit 52, external memory unit 53, operation unit 54, display unit 55, and transmission / reception unit 56 as resources. For example, the control device 210 executes the arm control step performed by the arm control unit 211, the hand control step performed by the hand control unit 212, the movement control step performed by the movement control unit 213, the suction control step performed by the suction control unit 214, the area calculation step performed by the area calculation unit 215, and the suction determination step performed by the suction determination unit 216.

[0071] (Details of the functional configuration of the control device 210 according to Embodiment 2) Returning to Figure 11, the arm control unit 211 controls the movement of the robot arm 200. For example, the arm control unit 211 controls the movement of the robot arm 200 and moves the robot hand 100 to a position where it contacts the object 300 and picks it up and grasps it.

[0072] When the arm control unit 211 moves the robot hand 100 to the above position, the hand control unit 212 controls the movement of the inner support unit 122 by the inner movement unit 130 and the suction of gas by the gas suction unit 140, thereby adjusting the size of the opening 116 of the suction pad 110 and controlling the suction and gripping of the object 300 by the suction pad 110.

[0073] When the arm control unit 211 moves the robot hand 100 to the above position, the area calculation unit 215 calculates the size of the object 300 from the image data of the object 300 captured by the camera 160, and calculates the area of ​​the opening 116 capable of holding the object 300 based on the calculated size of the object 300. For example, the area calculation unit 215 calculates the length of the shortest point on the top surface of the object 300, and calculates the area of ​​a circle with the calculated length as its outer diameter, thereby calculating the area of ​​the opening 116 capable of holding the object 300.

[0074] The movement control unit 213 controls the movement of the inner support unit 122 by the inner movement unit 130, for example, by controlling the servo motor 132 to rotate the drive shaft 133. The movement control unit 213 also controls the movement of the inner support unit 122 based on the area of ​​the opening 116 calculated by the area calculation unit 215. For example, the movement control unit 213 moves the inner support unit 122 downward to the free end side until the area of ​​the new opening 116 is less than or equal to the area calculated by the area calculation unit 215.

[0075] The suction control unit 214 controls, for example, the drive of the pump motor of a vacuum pump (not shown) of the gas suction unit 140 to discharge the air inside the container and maintain a vacuum, thereby drawing the air in the suction space 117 into the container via the suction tube 141 that extends to the suction port 115.

[0076] The adsorption determination unit 216 determines, for example, that the adsorption pad 110 is adsorbing the object 300 when the negative pressure sensor 150 detects that the suction space 117 is under negative pressure.

[0077] Here, if the suction determination unit 216 determines that the suction pad 110 is adsorbing the object 300, the arm control unit 211 controls the movement of the robot arm 200, lifting the object 300 that the robot hand 100 has adsorbed and grasped, and moving the object 300 to the target position.

[0078] At this time, the suction control unit 214 stops the suction of air in the suction space 117 by, for example, stopping the drive of the vacuum pump motor of the vacuum pump to release the vacuum inside the container. Also at this time, the movement control unit 213 moves the inner support part 122 upward with the inner movement part 130 and pulls back the lower end, which is the free end of the pad body 111 that protrudes downward, to enlarge the area of ​​the new opening 116. As a result, the suction of the object 300 by the suction pad 110 is released.

[0079] (Regarding the object suction and movement process according to Embodiment 2) Next, the operation in which the control device 210 causes the robot hand 100 to suction and grasp the object 300 and moves it to the desired position on the robot arm 200 will be described in detail. For example, when power is turned on to the robot arm 200, the control device 210 starts executing the object suction and movement process shown in Figure 13. First, the arm control unit 211 controls the movement of the robot arm 200 to move the robot hand 100 to a position where it contacts, suctions, and grasps the object 300 (step S1).

[0080] After the robot hand 100 moves, the area calculation unit 215 calculates the size of the object 300 from the image data of the object 300 captured by the camera 160, and calculates the area of ​​the opening 116 capable of adsorbing the object 300 based on the calculated size of the object 300 (step S2). After the area calculation, the movement control unit 213 moves the inner support unit 122 downward until the area of ​​the new opening 116 is less than or equal to the area calculated by the area calculation unit 215 (step S3). After the inner support unit 122 moves, the suction control unit 214 controls a vacuum pump (not shown) to suck air from the suction space 117 (step S4), and the adsorption determination unit 216 determines whether the suction pad 110 has adsorbed the object 300 by determining whether the negative pressure sensor 150 has detected that the suction space 117 is under negative pressure (step S5).

[0081] If the suction pad 110 does not pick up the object 300 (step S5; N), the control device 210 returns to step S2 and repeats the process from steps S2 to S5. On the other hand, if the suction pad 110 picks up the object 300 (step S5; Y), the arm control unit 211 controls the movement of the robot arm 200 so that the robot hand 100 picks up the object 300 that it has picked up and grasped, and moves the object 300 to the target position (step S6). After the object 300 has moved, the suction control unit 214 stops controlling the vacuum pump and stops the suction of air from the suction space 117 (step S7).

[0082] Furthermore, the movement control unit 213 moves the inner support portion 122 upward and pulls back the lower end, which is the free end of the pad body 111 that protrudes downward, to enlarge the area of ​​the new opening 116 (step S8), and returns to step S1. The control device 210 then repeats the processes of steps S1 to S8 until the power to the robot arm 200 is turned off, thereby repeatedly picking up, gripping, and moving a new object 300.

[0083] As described above, according to the control device 210 of this embodiment, the hand control unit 212 controls the movement of the inner support unit 122 by controlling the inner movement unit 130, and the suction control unit 214 controls the suction of gas by controlling the gas suction unit 140. In this way, the control device 210 of this embodiment can control the size of the opening 116 of the suction pad 110, and the suction and gripping of the object 300 by the suction pad 110, thereby controlling the robot hand 100.

[0084] Furthermore, according to the control device 210 of this embodiment, the area calculation unit 215 calculates the area of ​​the opening 116 of the suction pad 110 capable of adsorbing the object 300 based on the size of the object 300 identified from the image data of the object 300 captured by the camera 160. Then, the movement control unit 213 controls the movement of the inner support unit 122 based on the area of ​​the opening 116 calculated by the area calculation unit 215. In this way, the control device 210 of this embodiment can start adsorbing and gripping the object 300 only after the area of ​​the opening 116 of the suction pad 110 has become large enough to reliably adsorb the object 300.

[0085] Furthermore, according to the control device 210 of this embodiment, the suction determination unit 216 determines whether or not the suction pad 110 is adsorbing the object 300 based on the pressure in the suction space 117 detected by the negative pressure sensor 150 included in the robot hand 100. Then, if the suction determination unit 216 determines that the suction pad 110 is adsorbing the object 300, the arm control unit 211 controls the movement of the robot arm 200 that supports the robot hand 100 to move the object 300. In this way, the control device 210 of this embodiment can ensure that the suction pad 110 reliably adsorbs and grips the object 300 before moving the object 300 to the target position.

[0086] Furthermore, according to the control device 210 of this embodiment, the movement control unit 213 moves the inner support portion 122 after the suction control unit 214 stops controlling the suction of gas, thereby changing the area of ​​the new opening 116. In this way, the control device 210 of this embodiment makes it easier for the object 300 to detach from the suction pad 110 than a control device that does not move the inner support portion after stopping the control of gas suction to change the area of ​​the new opening. In addition, the robot hand 100 of this embodiment has the same effects and advantages as the robot hand 100 of Embodiment 1.

[0087] [Embodiment 3] In Embodiments 1 and 2, the inner moving part 130 moves the inner support part 122 vertically by moving the worm gear 137, which is meshed with the worm wheel gears 134 and 136, in the vertical direction by the rotation of the drive shaft 133 by the servo motor 132. However, the configuration of the inner moving part 130 is not limited to this. For example, the inner moving part 130 may be configured to move the inner support part 122 vertically by utilizing a so-called jamming transition. Hereinafter, the robot hand 100 and control device 210 according to Embodiment 3 will be described in detail with reference to Figures 14, 15A, 15B, and 16. Note that in Embodiment 3, a configuration different from Embodiment 2 will be described, and the same configuration as in Embodiment 2 will be omitted from the description as it would be redundant.

[0088] (Regarding the robot hand 100 according to Embodiment 3) As shown in Figure 14, in the robot hand 100 according to Embodiment 3 of the present invention, the internal moving part 130 omits the servo motor 132, each axis 133, 135, each worm wheel gear 134, 136, and worm gear 137 of Embodiment 2. In addition, the internal moving part 130 is provided with a telescopic part 310 that extends vertically and has a soft jamming structure, with its upper end supported by a frame 131 and its lower end fixed to an internal support part 122. The telescopic part 310 is formed in a cylindrical shape that extends vertically, and a third through-hole 311 that penetrates vertically is formed inside the cylinder. The lower end of the third through-hole 311 is continuous with the upper end of the first through-hole 123 of the internal support part 122, and the suction tube 141 of the gas suction part 140 extends through the through-holes 123 and 311 to the suction port 115.

[0089] Furthermore, the internal moving section 130 includes a pressure adjustment section 320 for adjusting the pressure in the internal space 114, and a pressure sensor 330 as an example of a second pressure detection section for detecting the pressure in the internal space 114.

[0090] The pressure adjustment unit 320 includes an air compressor (not shown) shared with the gas suction unit 140, and a ventilation tube 321 that penetrates the frame 131 and extends to the internal space 114. The pressure adjustment unit 320 increases the pressure in the internal space 114 by driving the air compressor under control from the control device 210 to discharge compressed air from the air compressor's storage tank and injecting the discharged air into the internal space 114 via the ventilation tube 321. On the other hand, the pressure adjustment unit 320 also decreases the pressure in the internal space 114 by driving the air compressor under control from the control device 210 to draw air into the storage tank, thereby drawing air from the internal space 114 into the tank via the ventilation tube 321.

[0091] In this embodiment, the gas suction unit 140, like the pressure adjustment unit 320, drives an air compressor under control from the control device 210 to draw air into the storage tank, thereby drawing air from the suction space 117 into the tank via the suction tube 141. Furthermore, in order to control it in this way, in this embodiment, the air compressor can be switched by control from the control device 210 between the operation of the gas suction unit 140, which draws air from the suction space 117 via the suction tube 141, and the operation of the pressure adjustment unit 320, which injects or draws air into the internal space 114 via the ventilation tube 321.

[0092] (Regarding the change in shape of the pad body 111 according to Embodiment 3) In this embodiment, when the robot hand 100 operates the pressure adjustment unit 320 under control from the control device 210 to increase the pressure in the internal space 114 until a predetermined pressure value is reached, the expandable portion 310 hardens while reducing its outer diameter, and the expandable portion 310 extends downward, causing the free end of the pad body 111 to be pushed out one step from the initial state shown in Figure 15A to the state shown in Figure 15B. In this case, the area of ​​the new opening 116 shown in Figure 15B is one step smaller than the area of ​​the opening 116 shown in Figure 15A. Also, in this case, at the new free end of the pad body 111 that has been pushed out one step to protrude as shown in Figure 15B, the second protruding portion 119, which is located at the lowest point, surrounds the outside of the new opening 116 and protrudes downward.

[0093] Although not shown in the diagram, each time the pressure adjustment unit 320 of the robot hand 100 increases the pressure in the internal space 114, the telescopic unit 310 extends further downward, causing the inner support unit 122 to move further downward, and the free end of the pad body 111 is pushed out in two, three, ... stages from the state shown in Figure 15B, resulting in a protruding state. As a result, the area of ​​the new opening 116 decreases by one stage each time the free end of the pad body 111 is pushed out in two, three, ... stages, and at the new free end, the second protruding parts 119, which are positioned second, third, ... from the bottom, surround the outside of the new opening 116 and protrude downward.

[0094] Meanwhile, each time the pressure adjustment unit 320 of the robot hand 100 lowers the pressure in the internal space 114, the expandable portion 310 softens while increasing its outer diameter, the expandable portion 310 shrinks upward, the inner support portion 122 moves upward, and the free end of the pad body 111 is pulled back, returning to the state shown in Figure 15B and the initial state shown in Figure 15A. As a result, the area of ​​the new opening 116 increases by one step each time the free end of the pad body 111 is pulled back, and at the new free end, the second protrusion 119 and the first protrusion 118, which are positioned second and first from the bottom, protrude downward, surrounding the outside of the new opening 116.

[0095] (Details of the functional configuration of the control device 210 according to Embodiment 3) As shown in Figure 16, in this embodiment, the movement control unit 213 adjusts the pressure in the internal space 114 by controlling the operation of the air compressor, which acts as a pressure adjustment unit 320, based on the pressure value of the internal space 114 obtained from the pressure sensor 330. As a result, the movement control unit 213 adjusts the vertical length of the expandable / contractible portion 310 of the internal movement unit 130 by adjusting the pressure in the internal space 114, thereby controlling the movement of the internal support unit 122. For example, after the area calculation unit 215 calculates the area of ​​the opening 116 capable of adsorbing an object 300, the movement control unit 213 injects air into the internal space 114 to extend the expandable / contractible portion 310 until the area of ​​the new opening 116 is less than or equal to the calculated area, thereby moving the internal support unit 122 downward to the free end side.

[0096] The suction control unit 214 controls the operation of the air compressor, which acts as the gas suction unit 140, to draw air into the storage tank, thereby drawing air from the suction space 117 into the tank via the suction tube 141 extending to the suction port 115. After the robot hand 100 has moved the object 300 that it has adsorbed and grasped to the target position, the suction control unit 214 stops the operation of the air compressor and stops the intake of air, thereby stopping the suction of air from the suction space 117. At this time, the movement control unit 213 uses the inner movement unit 130 to draw air from the internal space 114, causing the expandable / contractible unit 310 to shrink, which moves the inner support unit 122 upward, and pulls back the lower end, which is the free end of the pad body 111 that protrudes downward, to enlarge the area of ​​the new opening 116. As a result, the suction of the object 300 by the suction pad 110 is released.

[0097] (Regarding the object suction and movement process according to Embodiment 3) The operation in which the control device 210 causes the robot hand 100 to suction and grasp the object 300 and moves it to the target position on the robot arm 200 is the same as in Embodiment 2, except that in steps S3 and S8, the movement control unit 213 controls the operation of the air compressor to adjust the area of ​​the new opening 116, and in steps S4 and S7, the suction control unit 214 controls the suction of the object 300 by operating the air compressor. For this reason, in order to reduce redundant explanations, the illustrations and detailed explanations of the object suction and movement process according to this embodiment are omitted.

[0098] As described above, according to the robot hand 100 of this embodiment, the movement control unit 213 controls the movement of the inner support unit 122 by operating the pressure adjustment unit 320 to adjust the pressure in the internal space 114 based on the pressure value of the internal space 114 obtained from the pressure sensor 330, and by adjusting the vertical length of the extendable portion 310 of the inner movement unit 130. In this way, according to the robot hand 100 of this embodiment, the inner support unit 122 can be moved vertically without moving the worm gear 137, which extends vertically by the rotational drive of the servo motor 132, in the vertical direction, as in embodiments 1 and 2. Furthermore, the robot hand 100 of this embodiment has the same effects and advantages as the robot hand 100 of embodiments 1 and 2.

[0099] [Embodiment 4] In Embodiment 3, the retractable portion 310 of the inner moving portion 130 uses jamming transition to move the inner support portion 122 in the vertical direction, but the configuration of the retractable portion 310 is not limited to this. Hereinafter, the robot hand 100 and control device 210 according to Embodiment 4 will be described in detail with reference to Figures 17, 18A, and 18B. Note that in Embodiment 4, a configuration different from that of Embodiment 3 will be described, and the same configuration as in Embodiment 3 will be omitted from the description as it would be redundant.

[0100] (Regarding the robot hand 100 according to Embodiment 4) As shown in Figure 17, in the robot hand 100 according to Embodiment 4 of the present invention, the inner moving part 130 is provided with an extendable part 350 that extends in the vertical direction, with its upper end supported by a frame 131 and its lower end fixed to an inner support part 122, instead of the extendable part 310 of Embodiment 3. The extendable part 350 includes an upper fixed part 351 and a lower moving part 352.

[0101] The fixing portion 351 includes a cylindrical upper cylindrical portion 353 extending vertically as the fixing portion body, and a flange-shaped supported portion 354 extending radially from the upper end of the upper cylindrical portion 353. A fifth through hole 355 is formed in the cylindrical interior of the upper cylindrical portion 353, penetrating vertically. In addition, a plurality of protrusions 356 formed by surface texture processing are formed on the outer circumferential surface of the upper cylindrical portion 353 at intervals in the vertical direction, and a plurality of ventilation holes (not shown) penetrating radially from the cylinder are formed on the outer circumferential wall of the upper cylindrical portion 353 at intervals in the vertical direction. The supported portion 354 has its lower surface fixed to the frame 131, and a sixth through hole 357 is formed in the supported portion 354, penetrating vertically. The sixth through hole 357 is continuous in the vertical direction with the gap 358 between the upper cylindrical portion 353 and the frame 131, which penetrates the frame 131 vertically.

[0102] Furthermore, the movable part 352 includes a cylindrical lower section 359 that extends vertically as the main body of the movable part, and an inner support section 122 is integrally supported at the lower end of the lower section 359. A seventh through-hole 360 ​​that penetrates vertically is formed inside the cylinder of the lower section 359, and a plurality of ventilation holes (not shown) that penetrate in the radial direction of the cylinder are formed at vertical intervals on the outer circumferential wall of the lower section 359. The movable part 352 is supported so that it can move vertically with its upper part inserted upward from the lower end of the fifth through-hole 355 into the cylinder of the upper section 353. The lower end of the seventh through-hole 360 ​​is continuous with the upper end of the first through-hole 123 of the inner support section 122, and the suction tube 141 of the gas suction part 140 is connected to the fifth through-hole 355.

[0103] Furthermore, the outer surfaces of each cylindrical portion 353, 359 of the expandable portion 350 are covered by a cylindrical thin-film cylindrical member 361 that extends vertically, with its upper end fixed to the frame 131 and its lower end fixed to the inner support portion 122. Thus, a covered space 362, covered by the thin-film cylindrical member 361, is formed between the internal space 114 and the expandable portion 350. The thin-film cylindrical member 361 is made of a flexible silicone material similar to that of the pad body 111.

[0104] (Regarding the change in shape of the pad body 111 according to Embodiment 4) In this embodiment, when the robot hand 100 operates the pressure adjustment unit 320 under control from the control device 210 to increase the pressure in the internal space 114 to a predetermined pressure value, the thin film cylindrical member 361 is pressed toward the expandable portion 350, and the air in the covering space 362 is pushed out through the gap 358, each ventilation hole, and each through hole 123, 355, 360, causing the movable portion 352 of the expandable portion 350 to move downward, and the free end of the pad body 111 is pushed out one step from the initial state shown in Figure 18A to the state shown in Figure 18B, where it protrudes. In this case, the area of ​​the new opening 116 shown in Figure 18B is one step smaller than the area of ​​the opening 116 shown in Figure 18A. In this case, at the new free end of the pad body 111 shown in Figure 18B, which has been pushed out one step, the second protruding portion 119, which is located at the very bottom, surrounds the outside of the new opening 116 and protrudes downward.

[0105] At this time, the thin-film cylindrical member 361 is attached to the outer surface of the upper cylindrical portion 353, including the projection 356. Therefore, even if air from the suction space 117 is drawn into the tank from the suction port 115 in the state shown in Figure 18B, and negative pressure is generated, it is possible to prevent the expandable portion 350 from moving upward.

[0106] Although not shown in the diagram, each time the pressure adjustment unit 320 of the robot hand 100 increases the pressure in the internal space 114, the movable part 352 of the telescopic part 350 moves further downward, and the inner support part 122 moves further downward, so that the free end of the pad body 111 is pushed out in two, three, ... stages from the state shown in Figure 18B, and protrudes in two, three, ... stages. As a result, the area of ​​the new opening 116 decreases by one stage each time the free end of the pad body 111 is pushed out in two, three, ... stages, and at the new free end, the second protruding parts 119, which are positioned second, third, ... from the bottom, surround the outside of the new opening 116 and protrude downward.

[0107] Meanwhile, each time the pressure adjustment unit 320 of the robot hand 100 lowers the pressure in the internal space 114, air enters the covering space 362, pressing the thin-film cylindrical member 361 toward the internal space 114, causing the movable part 352 of the expandable / contractible part 350 to move upward, the inner support part 122 to move upward, and the free end of the pad body 111 to be pulled back, returning to the state shown in Figure 18B and the initial state shown in Figure 18A. As a result, the area of ​​the new opening 116 increases by one step each time the free end of the pad body 111 is pulled back, and at the new free end, the second protrusion 119 and the first protrusion 118, which are positioned second and first from the bottom, protrude downward, surrounding the outside of the new opening 116.

[0108] The functional configuration of the control device 210 according to this embodiment is the same as that of the control device 210 according to Embodiment 3, provided that "extendable part 310" is replaced with "extendable part 350". Therefore, in order to reduce redundant explanations, the functional configuration of the control device 210 according to this embodiment will not be illustrated or described in detail.

[0109] As described above, according to the robot hand 100 of this embodiment, the movement control unit 213 adjusts the pressure in the internal space 114 by operating the pressure adjustment unit 320 based on the pressure value of the internal space 114 obtained from the pressure sensor 330, and controls the movement of the inner support unit 122 by adjusting the vertical movement of the movement unit 352 of the expandable / contractible part 350 of the inner movement unit 130. In this way, according to the robot hand 100 of this embodiment, the inner support unit 122 can be moved vertically without using jamming transition as in Embodiment 3. Furthermore, the robot hand 100 of this embodiment has the same effects as the robot hand 100 of Embodiments 1 to 3.

[0110] (Example of modification) In embodiments 1 to 4 described above, the outer wall of the pad body 111 was formed in a substantially cylindrical shape, but it is not limited to this, and can be modified as long as it is possible to reduce the area of ​​the new opening 116 formed by the lower end, which is the free end of the pad body 111, being pushed outward and protruding downward. For example, the outer wall of the pad body 111 may be formed in a cylindrical shape with three or more polygons, or in an elliptical cylindrical shape.

[0111] In the above embodiments 1 to 4, the inner wall of the pad body 111 and the suction space 117 are formed in a substantially conical shape, but the invention is not limited to this, and can be arbitrarily modified as long as it is possible to reduce the area of ​​the new opening 116 formed by the lower end, which is the free end of the pad body 111, being pushed outward and protruding downward. For example, the inner wall of the pad body 111 and the suction space 117 may be formed in the shape of a polygonal cone with three or more sides, or in the shape of an elliptical cone. Furthermore, the generatrix of these cones is not limited to a straight line segment that extends inclined vertically from the vertex of the upper end on a plane perpendicular to the horizontal plane. For example, the generatrix of these cones may be a stepped line segment on a plane perpendicular to the horizontal plane, like the generatrix of a pyramid in a square pyramid. If the generatrix of the cone on the above plane is a stepped line segment, it is possible to change the area of ​​the new opening 116 in two or more steps by setting the number of steps to two or more.

[0112] As described in embodiments 1 to 4 above, it is preferable to provide the pad body 111 with a flexible first protrusion 118 and a plurality of second protrusions 119 in order to facilitate the suction pad 110's suction of the object 300. However, it is also possible to omit some or all of the protrusions 118 and 119. If all of the protrusions 118 and 119 are omitted, it becomes unnecessary to adjust the area of ​​the opening 116 in stages corresponding to the number of protrusions 118 and 119, as in embodiments 1 to 4 above, and the area of ​​the opening 116 can be adjusted steplessly.

[0113] In the embodiments 1 and 2 described above, the inner moving part 130 includes a servo motor 132, a driven worm wheel gear 134, a driven worm wheel gear 136, and a worm gear 137 as an example of a drive system. However, the drive system is not limited to this as long as it allows the inner support part 122 to move. For example, the inner moving part 130 may include a stepping motor, a pinion gear, and a rack gear as an example of a drive system instead of the servo motor 132, the driven worm wheel gear 134, the driven worm wheel gear 136, and the worm gear 137. Also, for example, the inner moving part 130 may include other drive systems that allow the movement of the inner support part 122 fixed to the end of the piston rod, such as an electromagnetic solenoid, a hydraulic cylinder, or a pneumatic cylinder.

[0114] In the embodiments 1 and 2 described above, a vacuum is generated by the vacuum pump of the gas suction unit 140 to suck out the air in the suction space 117. However, the gas suction unit 140 does not need to include a vacuum pump as long as it can suck out the air in the suction space 117. For example, the gas suction unit 140 may include a vacuum generator instead of a vacuum pump. In this case, the gas suction unit 140 may generate a vacuum by rapidly supplying and exhausting compressed air into the vacuum generator under control from the suction control unit 214 of the control device 210, thereby sucking out the air, which is the gas in the suction space 117, through the suction tube 141 extending to the suction port 115.

[0115] In the embodiments 1 and 2 described above, the suction tube 141 of the gas suction unit 140 is connected to the suction port 115 by passing through the first through hole 123 of the inner support unit 122 and the second through hole 138 of the worm gear 137 of the inner moving unit 130. However, the invention is not limited to this, and the suction tube 141 may also be connected to the suction port 115 by passing outside the inner support unit 122 and the worm gear 137. In this way, the robot hand 100 can omit the through holes 123 and 138.

[0116] In embodiments 2 to 4 described above, the movement control unit 213 moves the inner support portion 122 upward after the object 300 is released from suction, pulling the lower end of the protruding pad body 111 upward to increase the area of ​​the new opening 116, but the invention is not limited to this. For example, the movement control unit 213 may move the inner support portion 122 further downward after the object 300 is released from suction, pushing the lower end of the protruding pad body 111 further downward to further reduce the area of ​​the new opening 116. Alternatively, for example, a newly provided gas discharge portion (not shown) may discharge gas into the suction space 117 via the suction tube 141 after the object 300 is released from suction. Even in these cases, the object 300 will be easier to separate from the suction pad 110.

[0117] In embodiments 2 to 4 described above, the camera 160 is attached to the outer flexible portion 112 of the suction pad 110, but the attachment position is not limited to this, as long as the camera 160 can image the object 300. For example, the camera 160 may be attached to the robot arm 200, or to the wall or ceiling of the room where the robot arm 200 is installed. Alternatively, the camera 160 may be provided inside the robot hand 100, as long as the pad body 111 can suction the object 300. For example, the camera 160 may be provided in the suction space 117, or attached to the upper end of the outer flexible portion 112 near the suction port 115. Alternatively, for example, the camera 160 may be provided in the internal space 114 if the suction pad 110 is transparent and the object 300 can be imaged, or it may be fixed to the outer support portion 121 in the internal space 114.

[0118] In embodiments 1 to 4 described above, the internal space 114 of the pad body 111 contains no objects other than air. However, this is not limited to the case where the pad body 111 is elastically deformable. For example, small objects such as beads or fibers may be packed into the internal space 114. In this case, the strength and durability may be improved compared to the pad body 111 in which no objects other than air are contained in the internal space 114.

[0119] In the embodiments 1 to 4 described above, the color of the pad body 111 is not specified, but any color such as black, white, red, or blue can be used for the pad body 111. Alternatively, the pad body 111 may be made transparent. In this case, when the pad body 111 attracts the object 300, it is possible to check how the pad body 111 and the object 300 are in contact, and to check the shape of the internal space 114 and the suction space 117.

[0120] In embodiments 1 to 4 described above, an opening 116 is provided at the lower end of the suction pad 110 as a suction port. However, the arrangement and orientation of the opening 116 are not limited to this. For example, the opening 116 may be provided at the upper end of the suction pad 110 by inverting the robot arm 200, or the opening 116 may be provided at the right end and left end of the suction pad 110 by rotating the robot arm 200 by 90°. In this case, the orientation of the opening 116 will change from downward to upward, to the right, and to the left.

[0121] In the above embodiments 3 and 4, the pressure adjustment unit 320 shares an air compressor (not shown) with the gas suction unit 140, but the system is not limited to this, and the air compressor for the pressure adjustment unit 320 and the air compressor for the gas suction unit 140 may be provided separately.

[0122] In the above embodiment 3, the ventilation tube 321 of the pressure adjustment unit 320 penetrates the frame 131, but the embodiment is not limited to this, and a part of the ventilation tube 321 may pass outside the robot arm 200 and robot hand 100, with its lower end penetrating the outer flexible portion 112 and extending to the internal space 114.

[0123] Furthermore, the core processing portion of the control device 210, which includes a control unit 51, main memory unit 52, external memory unit 53, operation unit 54, transmission / reception unit 56, internal bus 60, etc., can be implemented using a normal computer system, not a dedicated system. For example, the control device 210 that performs the above processing may be configured by distributing a computer-readable recording medium, such as a flexible disk or DVD-ROM (Read-Only Memory), and installing the computer program on a computer. Alternatively, the computer program may be stored in a storage device on a server device on a communication network, and the control device 210 may be configured by downloading it from a normal computer system.

[0124] Furthermore, if the functions of the control device 210 are realized through a division of labor between the OS (Operating System) and the application program, or through cooperation between the OS and the application program, only the application program portion may be stored on the recording medium or storage device.

[0125] Furthermore, it is possible to superimpose a computer program onto the carrier wave and provide it via a communication network. For example, the computer program may be posted on a bulletin board system (BBS) on the communication network and provided via the network. The aforementioned processing may then be executed by starting this computer program and running it under the control of the OS, just like any other application program.

[0126] This invention allows for various embodiments and modifications without departing from the broad spirit and scope of the invention. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of the invention. In other words, the scope of the invention is indicated not by the embodiments, but by the claims. Various modifications made within the scope of the claims and the equivalent scope of the meaning of the invention are considered to be within the scope of the invention.

[0127] This application is based on Japanese Patent Application No. 2024-206741, filed on 27 November 2024. The entire specification, claims, and drawings of Japanese Patent Application No. 2024-206741 are incorporated herein by reference.

[0128] 51...Control unit, 52...Main memory unit, 53...External memory unit, 54...Operation unit, 55...Display unit, 56...Transmit / receive unit, 59...Control program, 60...Internal bus, 100...Robot hand, 110...Suction pad, 111...Pad body, 112...Outer flexible part, 113...Inner flexible part, 114...Internal space, 115...Suction port, 116...Opening, 117...Suction space, 118...First protrusion, 119...Second protrusion, 120...Pad support part, 121...Outer support part, 122...Inner support part, 123...First through hole, 130...Inner moving part, 131...Frame, 132...Servo motor, 133...Drive shaft, 134...Drive worm wheel gear, 135...Driven shaft, 136...Driven worm wheel gear, 137...Worm gear, 138...Second Through hole, 140...Gas suction section, 141...Suction tube, 150...Negative pressure sensor, 160...Camera, 200...Robot arm, 210...Control device, 211...Arm control unit, 212...Hand control unit, 213...Movement control unit, 214...Suction control unit, 215...Area calculation unit, 216...Adsorption determination unit, 300...Object, 310, 350...Extendable / Extendable section, 311...Third through hole Hole, 320... pressure adjustment part, 321... ventilation tube, 330... pressure sensor, 351... fixed part, 352... movable part, 353... upper cylindrical part, 354... supported part, 355... fifth through hole, 356... projection, 357... sixth through hole, 358... gap, 359... lower cylindrical part, 360... seventh through hole, 361... thin film cylindrical member, 362... covering space, 400... mold, 410... groove.

Claims

1. An adsorption pad comprising: a cylindrical pad body formed extending from a base end to a free end, wherein when an opening formed on the inside of the free end of the pad body is blocked by an object to be adsorbed, a gas suction space is formed surrounded by the blocked portion of the object and the inner wall of the pad body, and the object can be adsorbed by the gas being sucked in from a suction port formed on the inside of the base end of the pad body; a pad support portion that supports the base end of the pad body; and a gas suction portion that sucks the gas from the suction space from the suction port, wherein the pad body is made of a flexible member having flexibility, and an internal space is formed inside surrounded by an outer flexible portion as an outer wall and an inner flexible portion as an inner wall, wherein the pad support portion includes an outer support portion that supports the base end of the outer flexible portion and an inner support portion that supports the base end of the inner flexible portion, and further comprises an inner moving portion that moves the inner support portion relative to the outer support portion, The suction space has a larger cross-sectional area at the second position on the free end side than at the first position on the base end side, and the pad body has a cross-sectional area on a plane perpendicular to the straight line extending in the direction of extension of the pad body when the inner moving part moves the inner support part toward the free end side relative to the outer support part, the flexible member elastically deforms and the shape of the internal space changes, causing the free end to protrude outward, and the area of ​​the new opening formed by the protruding free end can be reduced, in a robot hand.

2. The suction space has an increasing cross-sectional area as it progresses from the base end to the free end, and the pad body has an increasing area of ​​the new opening as the inner support portion progresses from the base end to the free end, the robot hand according to claim 1.

3. The robot hand according to claim 2, wherein the pad body includes: a first projection formed to protrude outward from a free end and surround the outside of the opening; and a second projection formed to protrude into the suction space from an inner flexible portion and protrude outward from a new free end that protrudes when the inner moving portion moves the inner support portion toward the free end, and surrounds the outside of the new opening, wherein the first projection and the second projection are flexible and can adhere closely to the object.

4. A control device for controlling a robot hand according to claim 1, comprising: a movement control unit that controls the movement of the inner support unit by controlling the inner moving unit; and a suction control unit that controls the suction of gas by controlling the gas suction unit.

5. The control device according to claim 4, wherein the movement control unit moves the inner support portion to change the area of ​​the new opening after the suction control unit stops controlling the suction of the gas.

6. The control device according to claim 4, further comprising: an area calculation unit that calculates the area of ​​the opening capable of adsorbing the object based on the size of the object identified from the image data of the object captured by an imaging unit that images the object, wherein the movement control unit controls the movement of the inner support based on the area of ​​the opening calculated by the area calculation unit.

7. The control device according to claim 4, wherein the robot hand further comprises a pressure detection unit for detecting the pressure in the suction space, and the control device further comprises a suction determination unit for determining whether the suction pad is adsorbing an object based on the pressure detected by the pressure detection unit, and an arm control unit for controlling the movement of a robot arm supporting the robot hand to move the object when the suction determination unit determines that the suction pad is adsorbing an object.

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