Robot System

Abstract

To provide a hand for transportation which can hold and transport workpieces having various shapes stably and eliminates a need of exchange of an end effector according to a type of the workpiece.SOLUTION: A hand 200 for transportation according to the invention is attached to a tip of a robot arm 110 and suctions a workpiece 104 to transport the workpiece 104. A structure of the hand 200 for transportation includes at least three or more suction parts (a first suction part 210, a second suction part 220, and a third suction part 230) which rotate around concentric circles having different radii. The suction parts may rotate individually.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention is a transfer hand that is attached to the tip of a robot arm and picks up and transfers a workpiece. A robot system comprising: Regarding. [Background technology]

[0002] In recent years, industrial machines such as robot arms and manipulators have been used in production sites such as factories. Robot arms can perform a variety of processes, such as transporting and machining workpieces, depending on the type of end effector attached to the tip.

[0003] For example, Patent Document 1 discloses a workpiece pitch variable device for a robot in which four suction pads are arranged in the same straight line. With this configuration, it is possible to suitably pick up and transport long and thin workpieces. Furthermore, Patent Document 2 discloses a suction hand device in which three fingers are arranged at equal intervals on the same circumference. With this configuration, it is possible to suitably pick up and transport ring-shaped or circular workpieces. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-25392 [Patent Document 2] Japanese Utility Model Application Publication No. 60-74986 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the robot workpiece pitch variable device of Patent Document 1 is not suitable for transporting planar workpieces, and there is a risk that heavy block-shaped workpieces, in particular, will shake when transported at high speed, causing the workpiece to lose its grip due to the moment. Furthermore, the suction hand device of Patent Document 2 is suitable for transporting planar workpieces, but has difficulty in holding long, thin workpieces in a balanced manner. Therefore, there is room for further improvement in the technologies of Patent Documents 1 and 2.

[0006] In view of the above, the present invention provides a transfer hand that can stably hold and transfer workpieces of various shapes and does not require replacement of an end effector depending on the type of workpiece. A robot system comprising: The purpose is to provide. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention Robot System The typical configuration is: A robotic arm, A transfer hand attached to the tip of a robot arm that picks up and transfers workpieces a control device that controls the operation of the robot arm, and a camera that photographs the workpiece. And, The transport hand is a first suction portion, and a second suction portion and a third suction portion that rotate along concentric circles with different radii centered on the first suction portion; ,of The second suction portion and the third suction portion are independently rotatable, and the control device Calculate the center of gravity of the workpiece, The apparatus has an imaging unit that images a workpiece via a camera, and a workpiece recognition unit that extracts contours from the image captured by the imaging unit and performs object recognition processing to recognize the workpiece, and the workpiece recognized by the workpiece recognition unit Work calculated from The robot control unit 100 determines a predetermined position where the first suction unit should be placed in accordance with the center of gravity of the robot, and controls the robot arm so that the first suction unit is placed at the predetermined position, while rotating the second and third suction units. Note that "rotating along concentric circles" means that the trajectories of the movement of the second and third suction units describe concentric circles.

[0008] The suction units may be nozzles that suck air and the suction force may be individually controllable. Alternatively, the suction units may be electromagnets and the suction force may be individually turned on / off. Alternatively, the suction units may be individually turned on / off. [Effects of the Invention]

[0009] According to the present invention, a transfer hand can stably hold and transfer workpieces of various shapes, and does not require replacement of an end effector depending on the type of workpiece. A robot system comprising: can be provided. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating a robot system. [Figure 2] FIG. 2 is a schematic diagram illustrating a transport hand according to the present embodiment. [Figure 3] 3 is a schematic diagram illustrating an air flow path in the transport hand of FIG. 2. FIG. [Figure 4] 10A and 10B are diagrams illustrating positions of suction parts on a transport hand and a workpiece. [Figure 5] 10A and 10B are schematic diagrams illustrating another example of the transport hand of the present embodiment. [Figure 6] FIG. 2 is a diagram illustrating the control device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0012] (Robot System 100) Fig. 1 is a schematic diagram illustrating a robot system 100. As shown in Fig. 1, the robot system 100 includes a robot arm 110 and a control device 300 that controls the robot arm 110. As will be described later, the robot system 100 picks up (holds) a workpiece 104 using a transfer hand 200 and transfers it to a predetermined position. The control device 300 will be described later.

[0013] (Robot Arm 110) 1, the robot arm 110 has an arm 114, which is supported by a main body 112. At the tip of the arm 114, a transfer hand 200 of this embodiment, which is an end effector, and a camera 118 that captures an image of the workpiece 104 placed on the work table 106 are attached.

[0014] In this embodiment, the configuration in which the camera 118 is attached to the robot arm 110 via the arm 114 has been exemplified, but the present invention is not limited to this. The camera 118 may be attached to a device or member other than the robot arm 114, and for example, a configuration in which a member such as a support rod (not shown) is installed on the work table 106 and the camera 118 is fixed to the support rod is also possible.

[0015] (Transport hand 200) FIG. 2 is a schematic diagram illustrating a transfer hand 200 according to this embodiment. The transfer hand 200 shown in FIG. 2 is an end effector that is attached to the tip of the robot arm 110 and picks up and transfers the workpiece 104. The transfer hand 200 has the following features: The first suction part and the first suction part as the center Rotates along concentric circles with different radii No. 2 Adsorption part and the third suction portion The term "rotating along concentric circles" means No. 2 Adsorption part and the third suction portion This means that the trajectory of movement of the suction unit 100 draws concentric circles with different radii. In addition, although the configuration having three suction units is exemplified in this embodiment, the number of suction units is not limited to this, and can be changed as appropriate as long as it is three or more.

[0016] In this embodiment, the three suction units are nozzles that suck air and are composed of a first suction unit 210, a second suction unit 220, and a third suction unit 230. The first suction unit 210 is disposed at the center of a concentric circle. The second suction unit 220 is disposed outside the concentric circle drawn by the first suction unit 210. The third suction unit 230 is disposed outside the concentric circle drawn by the second suction unit 220.

[0017] The first suction unit 210 is fixed to a first cylinder 214 arranged coaxially with the first suction unit 210, and negative pressure is supplied (sucked) through the first cylinder 214. A second cylinder 224 is rotatably fitted around the first cylinder 214, and negative pressure is supplied to the second suction unit 220 through a second arm 226 and the second cylinder 224. Furthermore, a third cylinder 234 is rotatably fitted around the second cylinder 224, and negative pressure is supplied to the third suction unit 230 through a third arm 236 and the third cylinder 234.

[0018] The second motor 222 is a motor that rotates the second suction portion 220, and the third motor 232 is a motor that rotates the third suction portion 230. The second motor 222 is connected to the second suction portion 220 via a second cylinder 224 and a second arm 226. The third motor 232 is connected to the third suction portion 230 via a third cylinder 234 and a third arm 236. This allows the second suction portion 220 and the third suction portion 230 to rotate independently relative to the first suction portion.

[0019] 3 is a schematic diagram illustrating air flow paths in the transfer hand 200 of FIG. 2. Note that the second motor 222 and the third motor 232 are not shown in FIG. 3. As shown in FIG. 3, the first cylinder 214 of the first suction unit 210 is hollow, and the first cylinder 214 forms a part of the first air flow path 240. Air sucked from the second suction unit 220 passes through a second air flow path 250 that communicates with the second cylinder 224 and the second arm 226. Air sucked from the third suction unit 230 passes through a third air flow path 260 that communicates with the third cylinder 234 and the third arm 236.

[0020] A first ejector 242 and a first on-off valve 244 are provided between the first air flow path 240 and the pump 270 (compression pump). A second ejector 252 and a second on-off valve 254 are provided between the second air flow path 250 and the pump 270 (compression pump). A third ejector 262 and a third on-off valve 264 are provided between the third air flow path 260 and the pump 270 (compression pump). The first air flow path 240, the second air flow path 250, and the third air flow path 260 are connected to the downstream sides of the restrictors 242a, 252a, and 262a of the first ejector 242, the second ejector 252, and the third ejector 262, respectively.

[0021] To give an example of the flow of air from the first suction unit 210, when the pump 270 is operated and the first on-off valve 244 is opened, air is pressurized and sent from the pump 270 to the first ejector 242. As a result, the upstream side of the orifice 242a in the first ejector 242 is put into a high-pressure state, and when the air passes through the orifice, the downstream side of the orifice 242a is put into a reduced-pressure state. As a result, air passes through the first suction unit 210 and the first air flow path 240 and is sucked into the first ejector 242, and the workpiece 104 is sucked onto the first suction unit 210. The flow of air from the second suction unit 220 and the third suction unit 230 is similar to that from the first suction unit 210, and therefore a description thereof will be omitted.

[0022] According to the above configuration, by switching the opening and closing (ON / OFF) of the first on-off valve 244, the second on-off valve 254, and the third on-off valve 264, it is possible to change the number of suction units that suction the workpiece 104 in accordance with the size and weight of the workpiece 104. Furthermore, by adjusting the opening degrees of the first on-off valve 244, the second on-off valve 254, and the third on-off valve 264, it is possible to individually control the suction force when the suction units suction the workpiece 104.

[0023] In this embodiment, a pressure pump is used as the pump 270, and the first ejector 242, the second ejector 252, and the third ejector 262 are arranged between the pump 270 and the first air flow path 240, the second air flow path 250, and the third air flow path 260. However, the present invention is not limited to this, and it is possible to obtain the same effect as above by using a vacuum pump as the pump 270 without providing any ejectors.

[0024] FIG. 4 is a diagram illustrating the positions of the suction parts on the transport hand 200 and the workpiece. Fig. 4(a) illustrates a square-shaped workpiece 104a. Figs. 4(b) and 4(c) illustrate a thin, rod-shaped workpiece 104b. Fig. 4(d) illustrates a square-shaped workpiece 104c that is smaller in diameter than the transport hand 200.

[0025] 4(a), when a large planar or block-shaped workpiece 104a is to be sucked, the second suction unit 220 and the third suction unit 230 are rotated individually relative to the first suction unit 210 so that they are positioned within the range of the workpiece 104a. At this time, the workpiece 104a is sucked so that the center of gravity G of the workpiece 104a is within the triangle formed by the three suction units. This allows the large planar or block-shaped workpiece 104a to be suitably sucked by the first suction unit 210, the second suction unit 220, and the third suction unit 230.

[0026] 4(b), when adsorbing a long, thin rod-shaped workpiece, the second adsorption portion 220 and the third adsorption portion 230 are rotated individually so that the first adsorption portion 210, the second adsorption portion 220, and the third adsorption portion 230 are arranged in a straight line. This allows the long, thin rod-shaped workpiece 104b to be appropriately adsorbed by the first adsorption portion 210, the second adsorption portion 220, and the third adsorption portion 230.

[0027] 4(c), when adsorbing a long, thin rod-shaped workpiece 104b, if there is room to shift the first adsorption portion 210, the second adsorption portion 220, and the third adsorption portion 230, the three adsorption portions are individually rotated so that they are positioned at the vertices of a long, thin triangle (in the left-right direction in the drawing) arranged within the workpiece 10b. Even with such an arrangement, it is possible to appropriately adsorb the long, thin rod-shaped workpiece 104b.

[0028] As shown in FIG. 4(d), when a workpiece 104c having a square surface and smaller than the outer diameter of the transport hand 200 (the circle of the trajectory of the second suction unit 220) is to be sucked, the second on-off valve 254 and the third on-off valve 264 are closed. As a result, the workpiece 104c is sucked only by the first suction unit 210, whose first on-off valve 244 is open. This reduces air consumption. As described above, the transport hand 200 of this embodiment can stably hold and transport workpieces 104 of various shapes, making it possible to eliminate the need to change end effectors depending on the type of workpiece 104.

[0029] In this embodiment, the transport hand 200 is configured to rotate multiple suction units (the second suction unit 220 and the third suction unit 230) using multiple motors (the second motor 222 and the third motor 232), i.e., to change the relative positions of the multiple suction units. However, this configuration is merely an example, and the transport hand 200 does not necessarily have to include multiple motors. For example, a single motor can be attached to multiple suction units (the first suction unit 210, the second suction unit 220, and the third suction unit 230) via gears or the like, and rotate them at different gear ratios like the hour and minute hands of a clock, thereby achieving the same effect as described above.

[0030] (Another example of a transport hand) Fig. 5 is a schematic diagram illustrating another example of the transport hand of this embodiment. Note that components common to the transport hand 200 described above are denoted by the same reference numerals and description thereof will be omitted. Also, in Fig. 5, the second motor 222 and the third motor 232 are not shown, as in Fig. 3.

[0031] 5 uses electromagnets as the first suction portion 410, the second suction portion 420, and the third suction portion 430. A first wiring 412, a second wiring 422, and a third wiring 432 are connected to the first suction portion 410, the second wiring 420, and the third wiring 430. In addition, a first switch 414, a second switch 424, and a third switch 434 are provided between the power source 440 and the first wiring 412, the second wiring 422, and the third wiring 432.

[0032] When an electromagnet is used as the attraction part as described above, the attraction part to be used can be selected according to the shape and weight of the workpiece 104 by individually switching the first switch 414, the second switch 424, and the third switch 434 on and off. Therefore, it is possible to obtain the same effect as the transport hand 200 described above.

[0033] (Control device) Fig. 6 is a diagram illustrating the control device 300 of Fig. 1. In this embodiment, the control device 300 can calculate the center of gravity of the workpiece 104. As shown in Fig. 6, the control device 300 includes an imaging unit 310, a workpiece recognition unit 312, a center of gravity calculation unit 314, a placement determination unit 316, and a center of gravity storage unit 318.

[0034] When calculating the center of gravity of the workpiece 104, for example, the imaging unit 310 uses the camera 118 to capture an image of the workpiece 104 placed on the worktable 106. Then, the workpiece recognition unit 312 extracts contours from the captured image and performs object recognition processing to recognize the workpiece 104, and the center of gravity calculation unit 314 calculates the center of gravity of the recognized workpiece 104.

[0035] Once the center of gravity of the workpiece 104 has been calculated, the placement determination unit 316 determines the placement of the second suction unit 220 and the third suction unit 230 in accordance with this center of gravity, as shown in Fig. 4(a). This makes it possible to optimize the operation of the suction units and, ultimately, the transport hand 200. Furthermore, by placing the suction units in accordance with the center of gravity of the workpiece 104, it is possible to stably pick up a heavy workpiece 104.

[0036] In this embodiment, the workpiece 104 in the image is recognized by the workpiece recognition unit 312, and then the center of gravity of the workpiece 104 in the image is calculated, but this is not limited to this. For example, the type of workpiece 104 and its center of gravity may be linked and stored in the center of gravity storage unit 318, and the center of gravity of the workpiece 104 recognized by the workpiece recognition unit 312 may be determined by referring to the center of gravity storage unit 318. Furthermore, if the type of workpiece 104 is known in advance, it is also possible to determine the center of gravity by simply referring to the center of gravity storage unit 318.

[0037] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these examples. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that these modifications and alterations also fall within the technical scope of the present invention. [Industrial Applicability]

[0038] The present invention is a transfer hand that is attached to the tip of a robot arm and picks up and transfers a workpiece. A robot system comprising: It can be used as. [Explanation of symbols]

[0039] 100...Robot system, 110...Robot arm, 112...Main body, 114...Arm, 118...Camera, 200...Transport hand, 210...First suction part, 214...First cylinder, 220...Second suction part, 222...Second motor, 224...Second cylinder, 226...Second arm, 230...Third suction part, 232...Third motor, 234...Third cylinder, 236...Third arm, 240...First air flow path, 242...First ejector, 242a...Throttle, 244...First opening / closing valve, 250...Second air flow path, 252...Second ejector, 25 2a...throttle, 254...second on-off valve, 260...third air flow path, 262...third ejector, 262a...throttle, 264...third on-off valve, 270...pump, 300...control device, 310...imaging unit, 312...workpiece recognition unit, 314...center of gravity calculation unit, 316...placement determination unit, 318...center of gravity storage unit, 400...transport hand, 410...first suction unit, 412...first wiring, 414...first switch, 420...second suction unit, 422...second wiring, 424...second switch, 430...third suction unit, 432...third wiring, 434...third switch, 440...power supply

Claims

1. A robotic arm; a transport hand attached to the tip of the robot arm and configured to adsorb and transport a workpiece; a control device for controlling the operation of the robot arm; A camera that photographs the workpiece; A robot system comprising: The transport hand is A first suction portion; a second suction portion and a third suction portion that rotate along concentric circles having different radii centered on the first suction portion; Equipped with the second suction portion and the third suction portion are independently rotatable, The control device calculates the center of gravity of the workpiece, and An imaging unit that images the workpiece via the camera, and a workpiece recognition unit that extracts a contour from the image captured by the imaging unit and performs object recognition processing to recognize the workpiece, A robot system characterized by determining a predetermined position where the first suction part should be placed in accordance with the center of gravity of the workpiece recognized by the workpiece recognition unit, controlling the robot arm so that the first suction part is placed at the predetermined position, and rotating the second suction part and the third suction part.

2. The control device further includes a center of gravity calculation unit that calculates the center of gravity position of the work recognized by the work recognition unit, and a placement determination unit that determines placement positions of the first suction unit, the second suction unit, and the third suction unit in accordance with the center of gravity of the work calculated by the center of gravity calculation unit, The robot system according to claim 1, wherein the control device positions the first suction unit at the placement position determined by the placement determination unit and rotates the second suction unit and the third suction unit.

3. The robot system according to claim 1, characterized in that the control device positions the first suction portion and rotates the second suction portion and the third suction portion so that the center of gravity is within a triangle formed by the first suction portion, the second suction portion, and the third suction portion.

4. The control device further has a center of gravity storage unit in which data linking the type of the workpiece with the center of gravity is stored, The robot system according to claim 1, characterized in that the control device positions the first suction portion and rotates the second suction portion and the third suction portion in accordance with the center of gravity of the workpiece determined by the data stored in the center of gravity memory unit and the workpiece recognized by the workpiece recognition unit.

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