Control device, robot, robot system, program, control method, and end effector

Abstract

A control device according to the present invention controls a robot that comprises a grasping part that can open and close to grasp objects. The control device comprises a control unit. The control unit causes the robot to repeat movement / stoppage processing that is a sequence of movement processing that moves the grasping part and stoppage processing that stops the grasping part to position an object among a plurality of adjacent objects in an opening / closing area for the grasping part and controls the robot such that the grasping part grasps the object.

Description

Control Device, Robot, Robot System, Program, Control Method, and End Effector

[0001] The present disclosure relates to a technique for gripping an object.

[0002] Patent Document 1 describes a technique for gripping an object.

[0003] Japanese Patent Application Laid-Open No. 2010-120141

[0004] A control device, a robot, a robot system, a program, a control method, and an end effector are disclosed. In one embodiment, the control device controls a robot including a gripping part capable of gripping an object by opening and closing. The control device includes a control unit. The control unit causes the robot to execute a plurality of movement / stop processes in which a movement process for moving the gripping part and a stop process for stopping the gripping part are sequentially performed, positions an object included in a plurality of adjacent objects in the opening / closing region of the gripping part, and controls the robot so that the gripping part grips the object.

[0005] Also, in one embodiment, the robot is controlled by the above control device.

[0006] Also, in one embodiment, the robot system includes the above control device and the above robot.

[0007] Also, in one embodiment, the program is a program for causing a computer device to function as the above control device.

[0008] Also, in one embodiment, the control method controls a robot including a gripping part capable of gripping an object by opening and closing. The control method causes the robot to execute a plurality of movement / stop processes in which a movement process for moving the gripping part and a stop process for stopping the gripping part are sequentially performed, positions an object included in a plurality of adjacent objects in the opening / closing region of the gripping part, and controls the robot so that the gripping part grips the object.

[0009] Also, in one embodiment, the end effector includes a gripping part capable of gripping an object by opening and closing, and the gripping part has play in the opening / closing direction.

[0010] In one embodiment, the end effector includes a gripping portion that can grip an object by opening and closing, and the gripping portion is elastically deformable in the opening direction.

[0011] Figure 1 is a schematic diagram showing an example of a robot system. Figure 2 is a schematic diagram showing an example of a part of a robot system. Figure 3 is a schematic diagram showing an example of a drive mechanism. Figure 4 is a schematic diagram showing an example of a part of a finger. Figure 5 is a schematic diagram showing an example of a part of a finger. Figure 6 is a schematic diagram showing an example of a part of a finger. Figure 7 is a schematic diagram showing an example of a part of a finger. Figure 8 is a schematic diagram showing an example of a part of a finger. Figure 9 is a schematic diagram showing an example of how multiple fingers grasp an object. Figure 10 is a schematic diagram showing an example of a part of a finger. Figure 11 is a schematic diagram showing an example of the configuration of a control device. Figure 12 is a flowchart showing an example of the operation of a robot system. Figure 13 is a schematic diagram showing an example of the operation of a robot. Figure 14 is a schematic diagram showing an example of the operation of a robot. Figure 15 is a schematic diagram showing an example of the operation of a robot. Figure 16 is a schematic diagram showing an example of a rack and pinion. Figure 17 is a schematic diagram showing an example of a rack and pinion. Figure 18 is a schematic diagram showing an example of the opening width of the gripping part. Figure 19 is a schematic diagram showing an example of the movement of the gripping part when the robot performs movement and stopping operations. Figure 20 is a schematic diagram showing an example of the movement of the gripping part when the robot performs movement and stopping operations. Figure 21 is a schematic diagram showing an example of the movement of the gripping part when the robot performs movement and stopping operations. Figure 22 is a schematic diagram showing an example of the robot gripping and lifting an object. Figure 23 is a schematic diagram showing an example of the movement of the gripping part when the robot performs movement and stopping operations. Figure 24 is a schematic diagram showing an example of the gripping part elastically deforming in the opening direction. Figure 25 is a schematic diagram showing an example of the gripping part gripping an object while elastically deformed in the opening direction.

[0012] <Outline of an Example of a Robot System> Figure 1 is a schematic diagram showing an example of a robot system 100. As shown in Figure 1, the robot system 100 includes, for example, a robot 10 and a control device 1 that controls the robot 10. Figure 1 and the diagrams described later show the orthogonal xyz coordinate system used in the description of the robot system 100.

[0013] The robot 10, under the control of the control device 1, can, for example, hold an object 50 located at one place, move the held object 50 to another place, and place it there. The object 50 can also be called, for example, an object to be held, an object to be moved, or an object to be worked on. However, the tasks performed by the robot 10 are not limited to these.

[0014] The robot 10 is, for example, an arm-type robot. The robot 10 comprises, for example, an arm 11, an end effector 12 connected to the arm 11, and a sensor 30. The sensor 30 may be installed, for example, on the arm 11 side of the end effector 12.

[0015] The end effector 12 can hold an object 50 by, for example, gripping the object 50. The object 50 can also be called, for example, the object to be gripped. The end effector 12 includes a gripping section 13 that can grip an object by opening and closing. The gripping section 13 includes, for example, a plurality of openable and closable fingers 14. The plurality of fingers 14 can grip the object 50 by opening and closing. In this example, there are two fingers 14, but there may be three or more. An end effector 12 with a plurality of fingers 14 is also called, for example, a hand or a robot hand.

[0016] The arm 11 has, for example, a plurality of joints and a plurality of motors capable of rotating each of the plurality of joints. The posture of the arm 11 changes as the amount of rotation of at least one of the plurality of joints changes. In other words, the posture of the arm 11 changes as the amount of rotation of at least one of the plurality of motors capable of rotating each of the plurality of joints changes. And as the posture of the arm 11 changes, the position and posture of the end effector 12 changes. Also, as the posture of the arm 11 changes, the position and posture of the object 50 held by the gripping portion 13 of the end effector 12 changes.

[0017] The sensor 30 can, for example, detect the force acting on the gripping portion 13. The sensor 30 is, for example, a force sensor. The force sensor may be, for example, an electrical resistance type, a capacitive type, a piezoelectric type, or an optical type. The sensor 30 is located, for example, between the end effector 12 and the arm 11.

[0018] The robot 10 can, for example, grasp one object 50 from among multiple objects 50 placed on a mounting table 60 using its gripping unit 13. The mounting table 60 is, for example, positioned on a workbench 80. Figure 2 is a schematic diagram showing an enlarged view of the area around the mounting table 60. Note that in Figure 1, the number of objects 50 shown is smaller than in Figure 2 in order to avoid complexity in the drawing.

[0019] Object 50 is, for example, a rod-shaped member. Object 50 can also be described as a member that is long in one direction, or as a long, rectangular member. Object 50 is, for example, a long, slender pipe. Object 50 can also be described as a hollow cylindrical member. Object 50 is made of, for example, a metal such as stainless steel. However, the shape and material of object 50 are not limited to these. The shape of object 50 may be, for example, a rectangular parallelepiped, or a polygonal prism other than a rectangular parallelepiped. The material of object 50 may be, for example, resin.

[0020] The mounting surface 61 on the mounting table 60 on which the object 50 is placed is, for example, an inclined surface 61. In this embodiment, the inclined surface 61 is an inclined plane. Multiple objects 50 are placed adjacent to each other on the inclined surface 61. Multiple objects 50 are placed on the inclined surface 61 in a stacked manner, for example. Multiple objects 50 are placed on the inclined surface 61 such that, for example, the longitudinal direction of the object 50 intersects the inclination direction of the inclined surface 61. The mounting table 60 is provided with two stoppers 62 adjacent to the lower inclined end of the inclined surface 61 to prevent the object 50 from falling off the inclined surface 61.

[0021] Furthermore, the mounting surface 61 does not need to be inclined; it may be perpendicular to the direction of gravity (in other words, the vertical or z-direction) and parallel to the horizontal plane (in other words, the x-direction). In this case, the mounting base 60 does not need to be equipped with a stopper 62.

[0022] The robot 10, for example, grasps objects 50 one by one on the mounting surface 61 and moves the grasped objects 50 one by one into the tray 70 on the workbench 80. The gripping part 13 of the robot 10 grasps the side of the object 50, for example. The robot 10 moves the object 50 grasped by the gripping part 13 to the tray 70 by changing the posture of the arm 11. Then, the robot 10 places the object 50 into the tray 70 by having the gripping part 13 release its grip on the object 50. The robot 10 may also, for example, use a sensor 30 to detect when the gripping part 13 has come into contact with the tray 70 or a plurality of objects 50 placed in the tray 70, and then release the grip on the object 50. The robot 10 may also move the object 50 to a location other than the tray 70.

[0023] The configuration of robot 10 is not limited to the example above. For example, robot 10 may be equipped with a camera fixed to the end effector 12. The camera may be, for example, a 3D camera. Also, robot 10 may be equipped with sensors other than sensor 30.

[0024] <Example of End Effector Configuration> The end effector 12 is equipped with a drive mechanism 20 that opens and closes the gripping portion 13. The drive mechanism 20 can open and close the multiple finger portions 14 that the gripping portion 13 has.

[0025] Figure 3 is a schematic diagram showing an example of a drive mechanism 20. As shown in Figure 3, the drive mechanism 20 includes, for example, a rack and pinion mechanism 21 and a motor 25 that drives the rack and pinion mechanism 21. The rack and pinion mechanism 21 includes, for example, a pinion 22 and two racks 23 that engage with the pinion 22. The motor 25 can rotate the pinion 22. The two racks 23 move linearly along the x-direction in opposite directions to each other in response to the rotation of the pinion 22.

[0026] One finger portion 14 is fixed to one rack 23, and the other finger portion 14 is fixed to the other rack 23. When the pinion 22 rotates in one direction (counterclockwise in Figure 3), the two finger portions 14 fixed to the two racks 23 move toward each other along the x-direction to perform a closing operation. On the other hand, when the pinion 22 rotates in the opposite direction (clockwise in Figure 3), the two finger portions 14 fixed to the two racks 23 move toward each other along the x-direction to perform an opening operation. The control device 1 can control the opening and closing of the gripping portion 13, specifically the opening and closing of the multiple finger portions 14, by controlling the rotation of the motor 25. Hereafter, the direction of rotation of the pinion 22 in which the two finger portions 14 perform an opening operation will be referred to as the opening direction, and the direction of rotation of the pinion 22 in which the two finger portions 14 perform a closing operation will be referred to as the closing direction.

[0027] The end effector 12 is equipped with a rotation detection sensor 28 that detects the rotation of the motor 25. The rotation detection sensor 28 may be, for example, a rotary encoder. The detection result of the rotation detection sensor 28 is notified to the control device 1. The rotation detection sensor 28 and the drive mechanism 20 are housed within the housing of the end effector 12.

[0028] Each finger portion 14 of the gripping portion 13, as shown in Figure 1, comprises, for example, a driven portion 15 driven by a drive mechanism 20, and a first member 16 fixed to the driven portion 15. The first member 16 may be detachable from the driven portion 15.

[0029] Hereafter, in the description of the finger portion 14, the inner side of the finger portion 14 refers to the side of the other finger portion 14 that is opposite to the finger portion 14 in question. Also, the side opposite the inner side of the finger portion 14 will be called the outer side of the finger portion 14. For example, the inner side of the left finger portion 14 shown in Figure 1 is the right side (+x side) of Figure 1, and the outer side of the left finger portion 14 shown in Figure 1 is the left side (-x side) of Figure 1. The inner side of the finger portion 14 can also be called the gripping side that grasps the object 50. The two finger portions 14 each grasp the object 50 on their inner sides.

[0030] Furthermore, in the description of the finger portion 14, the upper side of the finger portion 14 refers to the arm 11 side (upper side or -z side in Figure 1), and the lower side of the finger portion 14 refers to the tip side of the finger portion 14 (lower side or +z side in Figure 1). Also, in the description of the gripping portion 13, simply referring to the opening and closing direction refers to the opening and closing direction of the gripping portion 13 (left-right direction or x direction in Figure 1). The opening and closing direction can also be said to be the opening and closing direction of the two finger portions 14. Also, in the description of the gripping portion 13, simply referring to the tip refers to the tip of the finger portion 14, that is, the tip of the gripping portion 13. The tip can also be said to be the lower end.

[0031] Each driven part 15 is, for example, a rectangular parallelepiped extending along the vertical direction (the vertical direction or z direction in Figure 1). The two driven parts 15 move linearly in opposite directions along the x direction by being driven by the drive mechanism 20. As shown in Figure 3, the two driven parts 15 are fixed to two racks 23 of the drive mechanism 20. As the racks 23 move, the driven parts 15 fixed to the racks 23 move.

[0032] The first member 16 is, for example, a plate-shaped member extending in the vertical direction (in other words, the z-direction). The first member 16 comprises, for example, a plate-shaped second member 17 fixed to the driven unit 15, and a plate-shaped third member 18 fixed to the second member 17. Each of the second member 17 and the third member 18 is, for example, a plate-shaped member extending in the vertical direction.

[0033] The third member 18 is fixed to the second member 17 by, for example, a plurality of screws 160 (see Figure 5, described later). The second member 17 may be detachable from the driven part 15. The second member 17 may be made of, for example, a metal such as stainless steel, or a resin. The third member 18 may be made of, for example, a metal such as stainless steel, or a resin.

[0034] In this example, there are two types of third members 18. Hereafter, one type of third member 18 will be referred to as third member 18a, and the other type of third member 18 will be referred to as third member 18b. One finger portion 14 has a third member 18a, and the other finger portion 14 has a third member 18b. The structure of the third member 18a and the structure of the third member 18b differ from each other in at least some respects. Below, the explanation common to both the third member 18a and the third member 18b will be explained using the third member 18. Note that the structure of the second member 17 on one finger portion 14 and the structure of the second member 17 on the other finger portion 14 are the same.

[0035] Figures 4 to 6 are schematic diagrams showing an example of a first member 16 having a third member 18a. Figure 4 shows an example of the first member 16 viewed from the outside, and Figure 5 shows an example of the first member 16 viewed from the inside. Figure 6 shows an example of the structure shown in Figure 5 viewed from the left side of Figure 5. The left side of Figure 6 shows the outside of the first member 16 (in other words, the outside of the finger portion 14), and the right side of Figure 6 shows the inside of the first member 16 (in other words, the inside of the finger portion 14).

[0036] Figures 7 and 8 are schematic diagrams showing an example of a first member 16 having a third member 18b. Figure 7 shows an example of the first member 16 viewed from the inside. Figure 8 shows an example of the structure shown in Figure 7 viewed from the right side of Figure 7. The left side of Figure 8 shows the inside of the first member 16 (in other words, the inside of the finger portion 14), and the right side of Figure 8 shows the outside of the first member 16 (in other words, the outside of the finger portion 14).

[0037] Each of the second member 17 and the third member 18 is, for example, a long plate-like shape. The upper portion of the second member 17 is fixed to the driven part 15, and the lower portion of the second member 17 is fixed to the upper portion of the third member 18. The second member 17 extends downward from the driven part 15, and the third member 18 extends downward from the second member 17. The thickness direction of the second member 17 and the third member 18 is aligned with the opening and closing direction.

[0038] Furthermore, the first member 16 and the third member 18 are formed in a rectangular shape, for example. Also, as shown in Figures 4, 5, and 7, for example, the tip of the first member 16 or the tip of the third member 18 has a width at the tip that is smaller than the width of the rest of the part. Specifically, the first member 16 or the third member 18 has a shape in which the lower corners of the rectangle are cut off, and can be said to be polygonal in shape.

[0039] As shown in Figures 5 and 7, the upper portion of the third member 18 (in other words, the -z side portion) is provided with multiple through holes 180 through which multiple screws 160 for fixing the second member 17 and the third member 18 are passed. Also, as shown in Figure 4, the lower portion of the second member 17 (in other words, the +z side portion) is provided with multiple screw holes 170. The screws 160 are passed through the through holes 180 from the inside of the third member 18 and screwed into the screw holes 170 of the second member 17. When the screws 160 are passed through the through holes 180 and screwed into the screw holes 170, the heads of the screws 160 do not protrude from the opening of the through holes 180 to the inside of the third member 18. That is, the heads of the screws 160 may be located inside the opening of the through holes 180.

[0040] In this embodiment, the second member 17 may have a plurality of through holes 180, and the third member 18 may have a plurality of screw holes 170. The screw 160 may be passed through the through holes 180 from the outside of the second member 17 and screwed into the screw holes 170 of the third member 18. When the screw 160 is passed through the through holes 180 and screwed into the screw holes 170, the head of the screw 160 does not protrude from the opening of the through holes 180 to the outside of the second member 17. In addition, screw holes 170 may be provided instead of through holes 180 in the second member 17 or the third member 18.

[0041] On the outer surface 181 of the third member 18, as shown in Figures 6 and 7, for example, a first region 182 between a position a predetermined distance above (in other words, on the -z side) from the lower end and the lower end is recessed inward compared to other regions, and a step is provided on the outer surface 181. In the example of Figures 4 to 7, the first region 182 is the lower quarter of the outer surface 181. On the outer surface 181, it can also be said that the first region 182 between a position a predetermined distance above the tip and the tip is one step lower. The outer surface 181 has a stepped surface 183 at a position a predetermined distance above the lower end. It can also be said that the outer surface 181 has a stepped surface 183 at a position recessed from the tip. In the third member 18, the thickness of the first portion 184 (for example, the lower quarter portion) between a position a predetermined distance from the lower end (in other words, the tip) and the lower end is smaller than the thickness of other portions. The outer surface of the first portion 184 becomes the first region 182.

[0042] The gripping portion 13 grips the object 50 with the inner surface 185 of the third member 18b and the inner surface 185 of the third member 18a. The inner surface 185 can also be called the gripping surface. The inner surface 185 of the third member 18b is, for example, flat, as shown in Figures 7 and 8. The thickness of the first portion 184 of the third member 18b is, for example, uniform.

[0043] On the other hand, as shown in Figure 6, the inner surface 185 of the third member 18a has a convex surface 186 in the region between a predetermined distance below the upper end and the upper end, and a step is provided on the inner surface 185 of the third member 18a. In the examples of Figures 4 to 6, the upper 12 / 13 of the inner surface 185 is convex surface 186. On the inner surface 185 of the third member 18a, it can be said that the region between a predetermined distance below the upper end and the upper end is raised by one step. The inner surface 185 of the third member 18a has a stepped surface 187 at a predetermined distance below the upper end.

[0044] The inner surface 185 of the third member 18a can also be seen as having a recessed area between the lower end and a position a predetermined distance above the lower end. In the examples of FIGS. 4 to 6, it can also be said that an area approximately 1 / 13 of the lower side of the inner surface 185 is recessed. In the inner surface 185 of the third member 18a, the area between the lower end and a position a predetermined distance above the lower end can also be seen as having a step-down. The inner surface 185 of the third member 18a can also be seen as having a stepped surface 187 at a position a predetermined distance above the lower end. The inner surface 185 of the third member 18a can also be said to have a stepped surface 187 at a position recessed from the tip.

[0045] The first portion 184 (for example, the lower approximately 1 / 4 portion) of the third member 18a is composed of a second portion 184a with a relatively large thickness and a third portion 184b with a relatively small thickness. The third portion 184b is a portion including the area of the inner surface 185 of the third member 18a other than the convex surface 186 and the stepped surface 187. The second portion 184a is the portion of the first portion 184 other than the third portion 18a. In the third member 18a, the stepped surface 187 is located at the boundary between the second portion 184a and the third portion 184b. For example, the thickness t1 (see FIG. 6) of the third portion 184b of the third member 18a and the thickness t2 (see FIG. 7) of the first portion 184 of the third member 18b are set to be the same.

[0046] The gripping portion 13 grips the object 50 with the first portion 184 of the third member 18a possessed by one finger portion 14 and the first portion 184 of the third member 18b possessed by the other finger portion 14. FIG. 9 is a schematic view showing an example of the state where the third member 18a and the third member 18b grip the object 50.

[0047] As shown in FIG. 9, in this example, the third portion 184b included in the first portion 184 of the third member 18a and the first portion 184 of the third member 18b grip the object 50.

[0048] Here, when the gripping portion 13 grips the object 50, the size of the object 50 in the opening and closing direction (in other words, the x direction) is defined as the width LP. Also, when the gripping portion 13 grips the object 50, the size of the object 50 in the longitudinal direction of the third member 18 (in other words, the vertical direction or the z direction) is defined as the height HP. In this example, the width LP and the height HP are the diameter of the hollow cylindrical object 50 and are the same as each other.

[0049] The opening width LA of the gripping portion 13 when the gripping portion 13 grips the object 50, that is, the opening width LA between the two finger portions 14 when the two finger portions 14 grip the object 50, matches the width LP of the object 50. It can also be said that the opening width LA is the distance between the two finger portions 14 (specifically, the distance in the x direction between the two finger portions 14).

[0050] The height LB of the stepped surface 187 that the third member 18a has inside is set to be smaller than the width LP of the object 50. When the gripping portion 13 grips the object 50, the opening width LA of the gripping portion 13 becomes larger than the height LB of the stepped surface 187. It can also be said that the height LB of the stepped surface 187 is the protruding amount (or also referred to as the protruding length) of the convex surface 186.

[0051] When the gripping portion 13 grips the object 50, as will be described later, the object 50 enters between the two finger portions 14 from between the tips of the two finger portions 14. At this time, the object 50 cannot enter deeper (in other words, upper side or -z side) than the stepped surface 187 that the third member 18a has. In this example, the stepped surface 187 that the third member 18a has functions as a blocking surface 187 that blocks the object 50 from entering deeper when the gripping portion 13 grips the object 50.

[0052] In the third member 18a, the distance HA from the tip to the stepped surface 187 (specifically, the distance HA from the tip to the stepped surface 187 in the vertical direction) is set to be, for example, not less than 1 / 2 of the height HP of the object 50 and less than 2 times the height HP. Or, for example, it may be set to be not less than the height HP of the object 50 and less than 1.5 times the height HP. Thereby, the possibility that the two finger portions 14 grip the two objects 50 such that the two objects 50 are arranged in the vertical direction is reduced. Therefore, the gripping portion 13 can more easily grip the objects 50 one by one.

[0053] Furthermore, if it is desired to grasp multiple objects 50 at once, the distance between the two finger portions 14 may be set to the width of one object 50, while the distance HA to the stepped surface 187 may be set to 1.5 times or more the HP of the object 50.

[0054] The thickness t1 of the third portion 184b of the third member 18a and the thickness t2 of the first portion 184 of the third member 18b are set to be smaller than the width LP of the object 50. The thicknesses t1 and t2 may be set to 1 / 2, 1 / 3, or 1 / 4 of the width LP.

[0055] The thickness t1 can also be seen as the size of the front surface of the third member 18a in the opening and closing direction. Therefore, in this example, it can be said that the size of the front surface of the third member 18a in the opening and closing direction is set to be smaller than the width LP of the object 50. The front surface of the third member 18a in the opening and closing direction can also be said to be the front surface of the third portion 184b.

[0056] Furthermore, the thickness t2 can also be seen as the size of the front surface of the third member 18b in the opening and closing direction. Therefore, in this example, it can be said that the size of the front surface of the third member 18b in the opening and closing direction is set to be smaller than the width LP of the object 50. The front surface of the third member 18b in the opening and closing direction can also be said to be the front surface of the first portion 184 of the third member 18a.

[0057] As shown in Figure 10, the first region 182 of the outer surface 181 of the third member 18a may not be a step down, but rather a tapered surface that slopes inward toward the tip. Similarly, the first region 182 of the outer surface 181 of the third member 18b may be a tapered surface that slopes inward toward the tip.

[0058] In this way, by setting the size of the tip surface of the gripping portion 13 in the opening and closing direction to be smaller than the width LP of the object 50, it becomes easier to grip objects 50 included in multiple adjacent objects 50.

[0059] Furthermore, the stepped surface 183 may be located above the stepped surface 187. As a result, it becomes easier to insert the multiple finger portions 14 towards the multiple objects 50 when gripping the object 50. Also, the lower end of the third member 18 may be thinned so that the distance between the multiple finger portions 14 increases towards the lower end of the third member 18.

[0060] <Example of Control Device Configuration> Figure 11 is a schematic diagram showing an example of the configuration of the control device 1. The control device 1 is, for example, a computer device. As shown in Figure 11, the control device 1 includes, for example, a control unit 2, a storage unit 3, and an interface 4. The control device 1 can also be called, for example, a control circuit.

[0061] Interface 4 can communicate with the robot 10. The detection results of the sensor 30 on the robot 10 are input to the control unit 2 through interface 4. Also, the detection results of the rotation detection sensor 28 on the robot 10 are input to the control unit 2 through interface 4. Interface 4 may communicate with the robot 10 via wired or wireless communication. Interface 4 can also be called, for example, a communication unit, a communication circuit, or an interface circuit.

[0062] The control unit 2 can comprehensively manage the operation of the control device 1 by controlling other components of the control device 1. The control unit 2 can also be called, for example, a control circuit. The control unit 2 includes at least one processor to provide control and processing capabilities for performing various functions, as will be described in more detail below.

[0063] According to various embodiments, at least one processor may be implemented as a single integrated circuit (IC) or as a plurality of communicably connected integrated circuits IC and / or discrete circuits. At least one processor can be implemented according to various known techniques.

[0064] In one embodiment, the processor includes one or more circuits or units configured to perform one or more data computation procedures or processes by, for example, executing instructions stored in associated memory. In other embodiments, the processor may be firmware (e.g., discrete logic components) configured to perform one or more data computation procedures or processes.

[0065] According to various embodiments, the processor may include one or more processors, controllers, microprocessors, microcontrollers, application-specific integrated circuits (ASICs), digital signal processing devices, programmable logic devices, field-programmable gate arrays, or any combination of these devices or configurations, or other known combinations of devices and configurations, and may perform the functions described below.

[0066] The control unit 2 may include, for example, a CPU (Central Processing Unit) as a processor. The control unit 2 can control the arm 11 and the end effector 12 through the interface 4. The control unit 2 can control the posture of the arm 11 through the interface 4. The control unit 2 can control the opening and closing of the gripping portion 13 of the end effector 12 through the interface 4. In other words, the control unit 2 can control the opening and closing of the multiple finger portions 14 of the gripping portion 13 through the interface 4. The control unit 2 can control the opening width LA of the gripping portion 13 through the interface 4. The control unit 2 can control the rotation of the motor 25 (see Figure 3) of the end effector 12 through the interface 4. By controlling the rotation of the motor 25, the control unit 2 can control the opening and closing of the gripping portion 13.

[0067] The storage unit 3 may include non-temporary recording media that can be read by the CPU of the control unit 2, such as ROM (Read Only Memory) and RAM (Random Access Memory). The storage unit 3 stores, for example, a program 3a for controlling the control device 1. Various functions of the control unit 2 are realized, for example, by the CPU of the control unit 2 executing the program 3a in the storage unit 3.

[0068] The configuration of the control device 1 is not limited to the above example. For example, the control unit 2 may include multiple CPUs. The control unit 2 may also include at least one DSP (Digital Signal Processor). Furthermore, all or some of the functions of the control unit 2 may be implemented by hardware circuits that do not require software to realize those functions. In addition, the storage unit 3 may include a computer-readable, non-temporary recording medium other than ROM and RAM. The storage unit 3 may include, for example, a small hard disk drive and an SSD (Solid State Drive).

[0069] Furthermore, the control device 1 may include a display unit controlled by the control unit 2. The display unit may be, for example, a liquid crystal display, an organic electroluminescent (EL) display, or a plasma display. The display unit of the control device 1 may, for example, display at least one of a color image and a depth image generated by a camera provided by the robot 10.

[0070] Furthermore, the control device 1 may include an input unit for receiving input from the user. The input unit may include, for example, a mouse and a keyboard. The input unit may also include a touch sensor for receiving user touch operations. The input unit may also include a microphone for receiving user voice input.

[0071] Furthermore, the control device 1 may be composed of multiple computer devices. For example, the control device 1 may include a first control device (in other words, a first computer device) that manages the overall control of the robot system 100, a second control device (in other words, a second computer device) that controls the arm 11, and a third control device (in other words, a third computer device) that controls the end effector 12. In this case, the first control device may control the arm 11 through the second control device and control the end effector 12 through the third control device. The control device 1 may also be a cloud server. In this case, the interface 4 of the control device 1 may communicate with the robot 10 through a network including the internet.

[0072] <Example of Robot System Operation> Figure 12 is a flowchart showing an example of the operation of the robot system 100. Figures 13 to 15 are schematic diagrams showing an example of the operation of the robot 10. In Figures 13 to 15, the area around the mounting platform 60 is shown in an enlarged view, similar to Figure 2.

[0073] When the robot 10 starts working, in step s1, the position of the gripping part 13 is set to its initial position at the start of work by the control unit 2 of the control device 1 controlling the posture of the arm 11. Figure 2 above shows an example of the gripping part 13 set to its initial position. The initial position is set, for example, vertically above the lower end of the inclined surface 61 (in other words, the mounting surface 61) on which the multiple objects 50 are placed.

[0074] The gripping portion 13 in its initial position is set to a posture in which its tip faces the mounting surface 61. The gripping portion 13 in its initial position is set to a posture in which, for example, the driven portion 15 and the first member 16 of the finger portion 14 are aligned in the vertical direction (in other words, the z direction). It can also be said that the gripping portion 13 in its initial position is set to a posture in which the second member 17 and the third member 18 included in the first member 16 of the finger portion 14 are aligned in the vertical direction.

[0075] After the gripping unit 13 is set to its initial position, step s2 is executed M times (where M is an integer of 2 or more). In step s2, the robot 10 performs a movement-stop process, which involves sequentially moving the gripping unit 13 and stopping the gripping unit 13. The robot 10 performs the movement-stop process by controlling the posture of the arm 11 by the control unit 2. After step s1, the movement-stop process is executed M times. For example, if M is set to 3, then after step s1, for example, the movement-stop process is executed 3 times. Hereafter, the M movements-stop processes may be collectively referred to as the M-process.

[0076] During the M-cycle process, the gripping portion 13 moves vertically downward (more specifically in the +z direction) from its initial position and strikes at least one object 50 on the mounting surface 61. During the M-cycle process, the gripping portion 13 moves along the longitudinal direction of the driven portion 15 of the finger portion 14 and the first member 16 and strikes at least one object 50 on the mounting surface 61. After the M-cycle process is completed, that is, after the movement and stopping process is completed M times, one object 50 on the mounting surface 61 is positioned within the opening and closing range of the gripping portion 13, as shown in Figure 13. In other words, one object 50 is positioned between the two finger portions 14. After the M-cycle process is completed, one object 50 is positioned between the third portion 184b of the third member 18a of one finger portion 14 and the first portion 184 of the third member 18b of the other finger portion 14. In this example, the control unit 2 controls the arm 11 to cause the robot 10 to perform movement and stopping processes M times, thereby positioning the object 50 included in the multiple adjacent objects 50 placed on the mounting surface 61 within the opening and closing area of ​​the gripping unit 13. The movement and stopping processes will be explained in detail later.

[0077] When step s2 is executed M times (i.e., when the movement and stopping process is executed M times), in step s3, the control unit 2 controls the motor 25 of the end effector 12 so that the gripping part 13 closes, causing the robot 10 to perform a closing process to close the gripping part 13. In other words, the control unit 2 causes the robot 10 to perform a closing process to close the two finger parts 14. By performing the closing process, the robot 10 can grip an object 50 located in the opening and closing region (in other words, an object 50 located between the multiple finger parts 14).

[0078] Next, in step s4, the control unit 2 of the control device 1 determines whether the gripping unit 13 has successfully gripped the object 50. The control unit 2 determines whether the gripping unit 13 has successfully gripped the object 50 based on, for example, the detection result of the rotation detection sensor 28 (see Figure 3) of the end effector 12. The control unit 2 identifies the current opening width LA of the gripping unit 13 based on, for example, the detection result of the rotation detection sensor 28. The control unit 2 then determines that the gripping unit 13 has successfully gripped the object 50 when the identified opening width LA matches the width LP of the object 50. On the other hand, the control unit 2 determines that the gripping unit 13 has failed to grip the object 50 when the identified opening width LA is smaller than the width LP of the object 50.

[0079] If the result in step s4 is YES, that is, if the gripping unit 13 successfully grips the object 50, the control unit 2 controls the arm 11 to move the object 50 gripped by the gripping unit 13 to the tray 70. Figure 14 shows the robot 10 moving the object 50 gripped by the gripping unit 13 toward the tray 70.

[0080] When the object 50 gripped by the gripping unit 13 moves to the top of the tray 70, the control unit 2 controls the motor 25 to open the gripping unit 13, causing the gripping unit 13 to release the object 50. As a result, the object 50 is placed inside the tray 70, as shown in Figure 15. Then, step s1 is executed again to set the position of the gripping unit 13 to its initial position. From there, the robot system 100 operates in the same manner.

[0081] If step s4 is determined to be NO, that is, if the gripping unit 13 fails to grip the object 50, step s1 is executed again and the position of the gripping unit 13 is set to the initial position. Thereafter, the robot system 100 operates in the same manner. Note that if the NO determination continues multiple times in step s4, the operation may be determined to be complete.

[0082] As described above, by repeatedly performing the processes s1 to s6 shown in Figure 12, the robot 10 grasps the objects 50 on the mounting table 60 one by one and moves them into the tray 70.

[0083] Thus, in this example, the control unit 2 causes the robot 10 to perform movement and stop processing M times, positioning the object 50 included in the multiple adjacent objects 50 within the opening and closing region of the gripping unit 13, and controls the robot 10 so that the gripping unit 13 grips the object 50. Since the control unit 2 can position the object 50 included in the multiple adjacent objects 50 within the opening and closing region of the gripping unit 13 by causing the robot 10 to perform movement and stop processing M times, the control unit 2 can cause the robot 10 to grip the object 50 with simple control of the robot 10.

[0084] <Example of movement and stopping process> In this example, there is backlash in the meshing between the pinion 22 and the rack 23 in the drive mechanism 20. As a result, the gripping part 13 has play in the opening and closing direction.

[0085] Figure 16 is a schematic diagram showing an example of how the pinion 22 and rack 23 mesh after the pinion 22 has rotated in the opening direction. Figure 17 is a schematic diagram showing an example of how the pinion 22 and rack 23 mesh after the pinion 22 has rotated in the closing direction.

[0086] As shown in Figure 16, when the pinion 22 stops rotating after it has rotated in the opening direction, a gap is created between the teeth of the pinion 22 and the teeth of the rack 23 at the meshing point between the pinion 22 and the rack 23, allowing the rack 23 to move so that the gripping portion 13 opens. Therefore, the gripping portion 13 has play in the opening direction after performing the opening operation.

[0087] On the other hand, when the pinion 22 stops rotating after it has rotated in the closing direction, as shown in Figure 17, a gap is created between the teeth of the pinion 22 and the teeth of the rack 23 at the meshing point between the pinion 22 and the rack 23, allowing the rack 23 to move so that the gripping portion 13 closes. Therefore, the gripping portion 13 has play in the closing direction after performing the closing operation.

[0088] In this example, for example, the gripping portion 13, which is initially positioned, is set to have some play in the opening direction. For example, after the gripping portion 13 is set to its initial position, the motor 25 controlled by the control unit 2 opens the gripping portion 13, thereby setting the gripping portion 13 to have some play in the opening direction. That is, before contacting multiple objects 50, the gripping portion 13 first closes to make its width smaller than the width LP of the objects 50, and then opens.

[0089] In this embodiment, the gripping portion 13 may be set to have no play. In this case, the gripping portion 13 should be opened to an opening width greater than or equal to the opening width that allows it to contact the multiple objects 50, and then closed.

[0090] Furthermore, the opening width LA of the gripping portion 13 in its initial position is set to be smaller than the width LP of the object 50. The gripping portion 13 in its initial position is set so that its opening width LA is smaller than the width LP of the object 50 and there is some play in the opening direction. Hereafter, the opening width LA of the gripping portion 13 in its initial position may be referred to as the initial opening width LA1.

[0091] Figure 18 is a schematic diagram showing an example of an initial opening width LA1. An example of the initial opening width LA1 is shown on the left side of Figure 18. On the right side of Figure 18, an example of the opening width LA (also called the maximum opening width LA2 due to play) when the gripping part 13 is opened to its maximum extent by the amount of play in the opening direction from the initial opening width LA1 is shown. For reference, the width LP of the object 50 is also shown in Figure 18.

[0092] Here, the maximum amount that the gripping part 13 opens due to the play in the opening direction is defined as the play opening amount LH. The maximum opening width LA2 due to the play is the sum of the initial opening width LA1 and the play opening amount LH.

[0093] As shown on the left side of Figure 18, the initial opening width LA1 is smaller than the width LP of the object 50. On the other hand, the maximum opening width LA2 due to play is greater than or equal to the width LP of the object 50, as shown on the right side of Figure 18. The maximum opening width LA2 due to play is, for example, greater than or equal to the width LP, and less than twice the width LP. Therefore, even when the gripping portion 13 is opened to its maximum extent by the amount of play in the opening direction, two or more objects 50 will not be aligned in the opening and closing direction between the two finger portions 14. The maximum opening width LA2 due to play may be, for example, 1.5 times or less the width LP, or 1.2 times or less the width LP.

[0094] After the gripping unit 13 is set to its initial position, the control unit 2 causes the robot 10 to perform the move / stop process M times, as described above. The control unit 2 causes the robot 10 to perform the move process of the move / stop process by controlling the arm 11 so that the gripping unit 13 moves vertically downward. During the execution of the move process, the gripping unit 13 moves vertically downward. After the start of the move process, the control unit 2 causes the robot 10 to perform the stop process based on the detection result of the sensor 30 which detects the force acting on the gripping unit 13. During the execution of the move process, the control unit 2 monitors the value indicated by the detection result of the sensor 30 (also called the force detection value). The force detection value indicates the force acting on the gripping unit 13. During the execution of the move process, if the force detection value becomes larger than a threshold value, the control unit 2 controls the arm 11 so that the movement of the gripping unit 13 stops, causing the robot 10 to perform the stop process of the move / stop process. For example, when the gripping portion 13 moves from its initial position toward the mounting surface 61 and the tip of the finger portion 14 of the gripping portion 13 comes into contact with the object 50, the detected force value becomes greater than the threshold. Note that the force acting on the end effector 12 is also detected by the sensor 30 when it comes into contact with something other than the object 50, for example, when it comes into contact with the mounting surface 61.

[0095] As a result of the above-described movement and stopping process being executed M times, one of the multiple objects 50 on the mounting surface 61 will be positioned within the opening and closing range of the gripping part 13. During the M processes, the gripping part 13 moves vertically downward from its initial position, and the tip of the gripping part 13 comes into contact with at least one object 50 on the mounting surface 61. When the tip of the gripping part 13 comes into contact with at least one object 50 during the M processes, the arrangement (in other words, the configuration) of the multiple objects 50 on the mounting surface 61 changes. Then, during the M processes, when the gripping part 13 attempts to move further vertically downward, one object 50 will try to enter between the two finger parts 14 of the gripping part 13. At this time, due to the play in the opening direction of the gripping part 13, the opening width LA of the two finger parts 14 increases, and one object 50 will be positioned between the two finger parts 14. After M processing cycles, the closing process in step s3 is executed, causing the two finger portions 14 to grasp a single object 50.

[0096] In the M-processing cycle, the use of camera images obtained from a camera, such as a 3D camera, may be restricted. Specifically, it is not necessary to estimate the holding position of object 50 using camera images. Furthermore, it is not necessary to perform object recognition of object 50 using camera images. The control unit 2 causes the robot 10 to perform the M-processing cycle without estimating the holding position or performing object recognition using camera images. This reduces the processing time for camera images and thus reduces the overall work time.

[0097] The control unit 2 may use the camera image to estimate the insertion position of the gripping unit 13. Alternatively, the control unit 2 may use the camera image to estimate the insertion position at regular intervals after multiple gripping operations. Furthermore, the control unit 2 may set the insertion position once using the camera image and then continue to use that set position. The control unit 2 does not need to perform any processing using the camera image at all. In this case, the insertion position of the gripping unit 13 can be set in advance by teaching or user operation. The control unit 2 may also not use the camera image when performing a gripping operation, but may use the camera image to confirm the completion of the operation when the gripping operation fails.

[0098] Figure 19 is a schematic diagram showing an example of the movement of the gripping part 13 during the first movement and stopping process. Figure 20 is a schematic diagram showing an example of the movement of the gripping part 13 during the second movement and stopping process. Figure 21 is a schematic diagram showing an example of the movement of the gripping part 13 during the third movement and stopping process. Note that the movement of the gripping part 13 shown in Figures 19 to 21 is an example of the movement of the gripping part 13 during M processes, and the gripping part 13 may move in a way different from the movement shown in Figures 19 to 21 during M processes.

[0099] In the first movement process (also called the first movement process), the gripping portion 13, whose opening width LA is smaller than the width LP of the object 50 and which has play in the opening direction, moves vertically downward (in other words, in the +z direction) from its initial position, as shown on the left side of Figure 19. Then, as shown in the center of Figure 19, in the first movement process, the tip of the moving gripping portion 13, specifically the tips of the third members 18a and 18b of the moving gripping portion 13, comes into contact with at least one object 50. As a result, at least one of the multiple objects 50 on the mounting surface 61 moves, and the arrangement of the multiple objects 50 on the mounting surface 61 changes, as shown on the right side of Figure 19, so that, for example, one object 50 is positioned near the gap between the third members 18a and 18b. If multiple objects 50 are piled up on the mounting surface 61, in the first movement process, the gripping part 13, which moves vertically downward (in other words, in the +z direction), will hit at least one object 50 on the mounting surface 61, causing the pile of objects 50 to collapse. When the tip of the gripping part 13 hits at least one object 50 in the first movement process, the force detection value becomes greater than the threshold, and the stop process of the first movement and stop process (also called the first stop process) is executed. When the first stop process is executed, the gripping part 13 stops in a state such as the one shown on the right side of Figure 19, that is, one object 50 is located near the gap between the third members 18a and 18b.

[0100] When the first stop process is executed and the first movement / stop process is completed, the movement process of the second movement / stop process (also called the second movement process) is executed. In the second movement process, the gripping part 13 moves vertically downward from the position where it stopped in the first stop process, so that, for example, an object 50 that was located near the gap between the third members 18a and 18b attempts to enter between the third members 18a and 18b. At this time, due to the play in the opening direction of the gripping part 13, the opening width LA of the third members 18a and 18b becomes larger than the width LP of the object 50, and as shown in Figure 20, for example, a part of one object 50 enters between the third members 18a and 18b. Specifically, a part of one object 50 enters between the third part 184b of the third member 18a and the first part 184 of the third member 18b. In the second movement process, for example, when the object 50 enters between the third members 18a and 18b, the friction between the object 50 and the third members 18a and 18b causes the force detection value to exceed the threshold, and the stop process of the second movement / stop process (also called the second stop process) is executed.

[0101] Once the second stop process is executed and the second movement / stop process is completed, the movement process of the third movement / stop process (also called the third movement process) is executed. In the third movement process, the gripping part 13 moves vertically downward from the position where it stopped in the second stop process, causing the object 50 to move further in between the third members 18a and 18b. As shown in Figure 21, for example, the tips of the third members 18a and 18b strike at least one object 50 located lower than the object 50 located between the third members 18a and 18b. Between the third members 18a and 18b, the object 50 does not move beyond the blocking surface 187 of the third member 18a.

[0102] When the tips of the third members 18a and 18b strike at least one object 50 located below the object 50 located between the third members 18a and 18b, for example, the force detection value becomes greater than the threshold value, and the stop process of the third movement / stop process (also called the third stop process) is executed, and the gripping part 13 stops.

[0103] When the third stop process is executed and the third movement / stop process is completed, one object 50 will be positioned between the third portion 184b of the third member 18a and the first portion 184 of the third member 18b (see Figure 21). In other words, when the movement / stop process is executed three times, one object 50 will be positioned between the third portion 184b of the third member 18a and the first portion 184 of the third member 18b. Subsequently, when the closing process of step s4 is executed, the object 50 will be grasped by the third portion 184b of the third member 18a and the first portion 184 of the third member 18b. Then, as the arm 11 is controlled, the object 50 grasped by the third portion 184b of the third member 18a and the first portion 184 of the third member 18b will be lifted and moved to the tray 70, as shown in Figure 22.

[0104] Depending on the arrangement of the object 50 on the mounting surface 61, the situation shown in Figure 21 may occur immediately after the second movement / stop process is executed. In this case, when the third movement process starts and the gripping part 13 attempts to move vertically downward, the force detection value becomes greater than the threshold value. Therefore, the third movement process will end immediately after it starts. When the control unit 2 causes the robot 10 to execute the third movement process, it attempts to move the gripping part 13 by controlling the arm 11 (specifically, by controlling the motor that rotates the joint of the arm 11), but the gripping part 13 does not actually move during the third movement process. If the situation shown in Figure 21 occurs immediately after the second movement / stop process is executed, the situation will not change from the situation shown in Figure 21 during the third movement / stop process, and the third movement / stop process will end.

[0105] Furthermore, the situation shown in Figure 21 may occur immediately after the first movement / stop process is executed. In this case, the gripping part 13 does not move during the second and third movement processes, and the situation does not change from that shown in Figure 21 during the second and third movement / stop processes.

[0106] Thus, in the movement process that moves the gripping portion 13, there are cases in which the gripping portion 13 does not actually move. The movement process of this disclosure also includes cases in which the control unit 2 attempts to move the gripping portion 13 by controlling the arm 11, but the gripping portion 13 does not actually move.

[0107] In the example shown in Figure 21, the movement process ends when the tips of the third members 18a and 18b strike at least one object 50 located below the object 50 located between the third members 18a and 18b. However, as shown in Figure 23, the movement process may also end when the tips of the third members 18a and 18b strike the mounting surface 61, causing the force detection value to exceed a threshold value.

[0108] Furthermore, during the movement process, the object 50 that enters between the third members 18a and 18b of the moving gripping portion 13 may come into contact with the blocking surface 187 of the third member 18a, causing the force detection value to exceed a threshold value and the movement process to terminate.

[0109] Furthermore, the movement speed of the gripping part 13 during the movement process and the threshold value compared with the force detection value during the movement process are set so that the object 50 is not damaged when the gripping part 13 contacts the object 50 during the M process. The threshold value of the force detection value is set so that the object 50 is not deformed by the contact of the gripping part 13. The threshold value of the force detection value may also be set within a range in which the object 50 can be elastically deformed.

[0110] In the example above, the initial opening width LA1 is set to be smaller than the width LP of the object 50, but it may also be set to be larger than or equal to the width LP. Even in this case, by setting the maximum opening width LA2 due to play to less than twice the width LP, it becomes difficult for two or more objects 50 to be aligned in the opening and closing direction between the two finger parts 14. As shown in the example in Figure 19, by setting the initial opening width LA1 to be smaller than the width LP of the object 50 and setting the distance between the two finger parts 14 to be narrow, it becomes easier to change the arrangement of multiple objects 50 on the mounting surface 61 during the first movement process. Therefore, it becomes easier for the objects 50 to fit between the two finger parts 14.

[0111] In the above example, the gripping portion 13 has play in the opening and closing direction, but it does not have to have play in the opening and closing direction. In other words, there does not have to be backlash in the meshing between the pinion 22 and the rack 23. In this case, the initial opening width LA1 may be set to be greater than or equal to the width LP of the object 50, and less than twice the width LP.

[0112] Furthermore, instead of having play in the opening and closing direction, the gripping portion 13 may be able to elastically deform in the opening direction. Figure 24 is a schematic diagram showing an example of the gripping portion 13 being elastically deformed in the opening direction. In the example of Figure 24, the upper end of each driven portion 15 is elastically deformed, causing each finger portion 14 to be elastically deformed such that the distance between the tips of the two finger portions 14 increases. In this case, the opening width LA of the gripping portion 13 is the distance between the tips of the two finger portions 14.

[0113] Furthermore, the gripping portion 13 may elastically deform in the opening direction due to the elastic deformation of the plate-shaped first member 16. In this case, the gripping portion 13 may elastically deform in the opening direction due to the elastic deformation of at least one of the second member 17 and the third member 18 of the first member 16. Alternatively, the gripping portion 13 may elastically deform in the opening direction due to the elastic deformation of both the driven portion 15 and the first member 16.

[0114] If the gripping portion 13 is elastically deformable in the opening direction, the initial opening width LA1 may be set to less than the width LP of the object 50, similar to the example in Figure 19. For example, consider the case where, as shown at the far right of Figure 19, one object 50 is located near the gap between the third members 18a and 18b when the first movement and stopping process is completed. In this case, during the second movement process, the gripping portion 13 moves vertically downward from the position where it stopped during the first stopping process, causing the object 50 that was located near the gap between the third members 18a and 18b to attempt to enter the gap between the third members 18a and 18b from the tip side of the gripping portion 13. At this time, the gripping portion 13 elastically deforms in the opening direction, and as shown in Figure 25, a part of one object 50 enters the gap between the third members 18a and 18b. Thereafter, the robot system 100 operates similarly, allowing the third members 18a and 18b to grip one object 50.

[0115] The gripping portion 13 may have play in the opening and closing direction and may also be elastically deformable in the opening direction. In this case, if an object 50 attempts to enter between the third members 18a and 18b from the tip side of the gripping portion 13, the opening width LA of the third members 18a and 18b will increase due to the play in the opening direction of the gripping portion 13, and the object 50 may enter between the third members 18a and 18b as the gripping portion 13 elastically deforms in the opening direction.

[0116] Furthermore, in the above example, an example of vertical downward movement was described in the M-process movement, but the gripping part 13 may move horizontally during the movement process. Also, in the above example, the case where M=3 was described in the M-process, but M=4 or more is also acceptable, and M=2 or less is also acceptable. Also, in the above example, the case where M=3 was described in the M-process, but M=1 is also acceptable.

[0117] Furthermore, although the above example describes inserting the gripping portion 13 into the multiple objects 50 from the lower ends of the multiple finger portions 14, the gripping portion 13 may also be inserted into the multiple objects 50 from the corners of the lower ends of the multiple finger portions 14.

[0118] As described above, the robotic system has been explained in detail, but the above explanation is illustrative in all respects, and this disclosure is not limited thereto. Furthermore, the various examples described above can be combined and applied insofar as they do not contradict each other. And it is understood that countless examples not illustrated can be conceivable without falling outside the scope of this disclosure.

[0119] This disclosure includes the following:

[0120] In one embodiment, (1) the control device is a control device for controlling a robot equipped with a gripping part capable of gripping an object by opening and closing, and includes a control unit that controls the robot to perform a movement-stop process multiple times, in which a movement process to move the gripping part and a stop process to stop the gripping part are performed in sequence, so that an object included in a plurality of adjacent objects is positioned in the opening and closing region of the gripping part, and the gripping part grips the object.

[0121] (2) The control device of (1) above, wherein the control unit causes the robot to perform the stop process based on the detection result of a sensor that detects the force acting on the gripping part after the start of the movement process.

[0122] (3) The control device according to (1) or (2) above, wherein the gripping portion has play in the opening direction at the start of the first movement / stop process among multiple movement / stop processes.

[0123] (4) The control device according to (3) above, wherein the maximum opening width of the gripping portion due to the play at the start of the initial movement / stopping process is less than twice the size of the object in the opening and closing direction of the gripping portion when the gripping portion grips the object.

[0124] (5) Any one of the control devices described in (1) to (4) above, wherein the gripping portion is capable of elastically deforming in the opening direction.

[0125] (6) Any one of the control devices described in (3) to (5) above, wherein the control unit controls the robot such that the first of multiple movement and stop processes begins when the opening width of the gripping portion is smaller than the size of the object in the opening and closing direction of the gripping portion when the gripping portion grips the object.

[0126] In one embodiment, (7) the robot is a robot controlled by any one of the control devices described in (1) to (6) above.

[0127] (8) The robot according to (7) above, wherein the inner surface of the gripping portion has a blocking surface located in a recessed position from the tip, which prevents the object from penetrating further when the gripping portion grips the object.

[0128] (9) The robot according to (7) or (8) above, wherein the size of the tip surface of the gripping part in the opening and closing direction of the gripping part is smaller than the size of the object in the opening and closing direction when the gripping part grips the object.

[0129] In one embodiment, the (10) robot system comprises one control device from (1) to (6) above and one robot from (7) to (9) above.

[0130] In one embodiment, program (11) is a program that causes the computer device to function as one of the control devices described in (1) to (6) above.

[0131] In one embodiment, (12) the control method is a control method for controlling a robot equipped with a gripping part capable of gripping an object by opening and closing, wherein the robot is made to perform a movement / stopping process multiple times, in which a movement process to move the gripping part and a stopping process to stop the gripping part are performed in sequence, thereby positioning an object included in a plurality of adjacent objects within the opening and closing region of the gripping part, and controlling the robot so that the gripping part grips the object.

[0132] In one embodiment, (13) the end effector is provided with a gripping portion that can grip an object by opening and closing, and the gripping portion has play in the opening and closing direction.

[0133] In one embodiment, (14) the end effector is provided with a gripping portion that can grip an object by opening and closing, and the gripping portion is elastically deformable in the opening direction.

[0134] (15) The end effector according to (13) or (14) above, wherein the inner surface of the gripping portion has a blocking surface located recessed from the tip, which prevents the object from penetrating further when the gripping portion grips the object.

[0135] (16) Any one of the end effectors described in (13) to (15) above, wherein the size of the tip surface of the gripping portion in the opening and closing direction of the gripping portion is smaller than the size of the object in the opening and closing direction when the gripping portion grips the object.

[0136] 1 Control device 2 Control unit 3a Program 10 Robot 13 Gripping unit 50 Object 100 Robot system 187 Blocking surface LA Opening width LP Width of object

Claims

1. A control device for controlling a robot equipped with a gripping part capable of gripping an object by opening and closing, comprising a control unit that controls the robot to perform a movement / stop process multiple times, in which a movement process to move the gripping part and a stop process to stop the gripping part are performed in sequence, thereby positioning an object included in a plurality of adjacent objects within the opening / closing region of the gripping part, and causing the gripping part to grip the object.

2. A control device according to claim 1, wherein the control unit causes the robot to perform the stop process based on the detection result of a sensor that detects the force acting on the gripping part after the start of the movement process.

3. A control device according to claim 1 or claim 2, wherein the gripping portion has play in the opening direction at the start of the first movement / stop process among a plurality of movement / stop processes.

4. A control device according to claim 3, wherein the maximum opening width of the gripping portion due to the play at the start of the initial movement / stopping process is less than twice the size of the object in the opening / closing direction of the gripping portion when the gripping portion grips the object.

5. A control device according to any one of claims 1 to 4, wherein the gripping portion is capable of elastically deforming in the opening direction.

6. A control device according to any one of claims 3 to 5, wherein the control unit controls the robot such that the first of multiple movement and stop processes begins when the opening width of the gripping portion is smaller than the size of the object in the opening and closing direction of the gripping portion when the gripping portion grips the object.

7. A robot controlled by a control device according to any one of claims 1 to 6.

8. A robot according to claim 7, wherein the inner surface of the gripping portion has a blocking surface located recessed from the tip, which prevents the object from penetrating further when the gripping portion grips the object.

9. A robot according to claim 7 or claim 8, wherein the size of the tip surface of the gripping portion in the opening and closing direction of the gripping portion is smaller than the size of the object in the opening and closing direction when the gripping portion grips the object.

10. A robot system comprising a control device according to any one of claims 1 to 6, and a robot controlled by the control device.

11. A program for causing a computer device to function as a control device according to any one of claims 1 to 6.

12. A control method for controlling a robot equipped with a gripping part capable of gripping an object by opening and closing, wherein the robot is made to perform a movement-stop process multiple times, in which a movement process for moving the gripping part and a stop process for stopping the gripping part are performed in sequence, thereby positioning an object included in a plurality of adjacent objects within the opening and closing region of the gripping part, and controlling the robot so that the gripping part grips the object.

13. An end effector having a gripping portion capable of gripping an object by opening and closing, wherein the gripping portion has play in the opening and closing direction.

14. An end effector comprising a gripping portion capable of gripping an object by opening and closing, wherein the gripping portion is elastically deformable in the opening direction.

15. An end effector according to claim 13 or claim 14, wherein the inner surface of the gripping portion has a blocking surface located recessed from the tip, which prevents the object from penetrating further when the gripping portion grips the object.

16. An end effector according to any one of claims 13 to 15, wherein the size of the tip surface of the gripping portion in the opening and closing direction of the gripping portion is smaller than the size of the object in the opening and closing direction when the gripping portion grips the object.

Images