Workpiece removal device, workpiece removal method, program and control device

Abstract

To inhibit failure in holding of a workpiece to take out the workpiece without fail.SOLUTION: A workpiece takeout device takes out a workpiece from multiple linear workpieces placed in a three-dimensional space one by one. The workpiece takeout device includes: holding means which holds the workpiece; and control means which controls the holding means so that the workpiece held by the holding means draws a circular or rectangular trajectory after the holding means holds the workpiece.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a workpiece removal device, a workpiece removal method, a program, and a control device for removing a workpiece. [Background technology]

[0002] 2. Description of the Related Art A workpiece removal device is known that grips and removes workpieces one by one from among a plurality of workpieces placed in a three-dimensional space (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-128191 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the above-mentioned workpiece unloading device grips a linear workpiece, for example, the workpieces may become entangled with each other, which may result in a risk of failing to grip the workpieces, such as gripping multiple workpieces at the same time.

[0005] The present invention has been made to solve such problems, and its main object is to provide a workpiece removal device, a workpiece removal method, a program, and a control device that can prevent failure to grasp the workpiece and reliably remove the workpiece. [Means for solving the problem]

[0006] In order to achieve the above object, one aspect of the present invention is to A workpiece removal device that removes workpieces one by one from a plurality of linear workpieces placed in a three-dimensional space, A gripping means for gripping the workpiece; a control means for controlling the gripping means so that the workpiece gripped by the gripping means moves along a circular or rectangular trajectory after the gripping means grips the workpiece; Equipped with Workpiece removal device It is. In one aspect of this invention, the gripping means may further include a judgment means for judging whether the gripping means has succeeded in gripping the workpiece, and the control means may control the gripping means so that the workpiece gripped by the gripping means traces a circular or rectangular trajectory only when the judgment means judges that gripping of the workpiece has failed. In this one aspect, after the gripping means is controlled so that the workpiece gripped by the gripping means traces a circular trajectory, the judgment means again judges whether the gripping means has successfully gripped the workpiece, and the control means may control the gripping means so that the workpiece gripped by the gripping means traces a circular or rectangular trajectory depending on the judgment result by the judgment means. In this one aspect, the control means may control the gripping means so that the workpiece gripped by the gripping means revolves around a circular or rectangular orbit and at least one of rotating the workpiece gripped by the gripping means and vibrating the workpiece gripped by the gripping means. In one aspect of this invention, the workpiece may further include a torque detection means for detecting the torque when the workpiece moves in a circular or rectangular trajectory, and when the control means determines that the torque detected by the torque detection means is equal to or greater than a predetermined value, the control means may control the gripping means so that the workpiece gripped by the gripping means moves in a circular or rectangular trajectory and vibrates the workpiece gripped by the gripping means. In one embodiment of this invention, the system further includes an acquisition means for acquiring three-dimensional information of the multiple linear workpieces, and the control means calculates the distance from the gripping point at which the gripping means grips the workpiece to the maximum height position of the multiple linear workpieces based on the three-dimensional information of the multiple linear workpieces acquired by the acquisition means, and may determine the operation of the workpiece after the gripping means grips the workpiece based on the calculated distance. In this aspect, the control means may increase the amount of movement of the workpiece as the distance increases. In one embodiment of this invention, the multiple linear workpieces in the three-dimensional space are arranged in a wound state, and the system further includes a radius information acquisition means for acquiring information on the radius of the workpiece in the wound state, and the control means determines a radius of a circular orbit of the workpiece gripped by the gripping means based on the information on the radius of the workpiece acquired by the radius information acquisition means, and controls the gripping means so that the workpiece describes a circular orbit based on the determined radius. In order to achieve the above object, one aspect of the present invention is to A method for removing workpieces one by one from a plurality of linear workpieces placed in a three-dimensional space, comprising the steps of: A step of gripping the workpiece; After gripping the workpiece, moving the gripped workpiece so that the gripped workpiece describes a circular or rectangular trajectory; Including, How to remove the workpiece may be also possible. In order to achieve the above object, one aspect of the present invention is to A process of grasping each of a plurality of linear workpieces placed in a three-dimensional space one by one; A process of gripping the workpiece and then moving the gripped workpiece so that the gripped workpiece describes a circular or rectangular trajectory; to cause a computer to execute program may be also possible. In order to achieve the above object, one aspect of the present invention is to A control device that controls the picking out of a plurality of linear workpieces placed in a three-dimensional space one by one, After the gripping means grips the workpiece, the gripping means is controlled so that the workpiece gripped by the gripping means moves along a circular or rectangular trajectory. Control device may be also possible. Effect of the Invention

[0007] According to the present invention, it is possible to provide a workpiece removal device, a workpiece removal method, a program, and a control device that can suppress failure to grip a workpiece and reliably remove the workpiece. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing a schematic system configuration of a workpiece removal device according to an embodiment of the present invention; [Diagram 2] 1 is a block diagram showing a schematic system configuration of a control device according to an embodiment of the present invention; [Diagram 3] 4 is a flowchart showing a flow of a workpiece unloading method according to the present embodiment. [Figure 4] 1 is a block diagram showing a schematic system configuration of a control device according to an embodiment of the present invention; [Diagram 5] FIG. 13 is a diagram showing the distance from the gripping point of the workpiece to the maximum height position of the workpiece. [Figure 6] FIG. [Figure 7] 4 is a flowchart showing a flow of a workpiece unloading method according to the present embodiment. [Figure 8] 10A to 10C are diagrams for explaining a workpiece removal method according to the present embodiment. [Figure 9] 1 is a block diagram showing a schematic system configuration of a control device according to an embodiment of the present invention; [Figure 10] FIG. 1 shows a circular trajectory corresponding to the radius of the cable. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] EMBODIMENT 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic system configuration of a workpiece extraction device according to this embodiment. The workpiece extraction device 1 according to this embodiment can grip and move each of a plurality of linear workpieces arranged in a three-dimensional space. The linear workpiece is, for example, a cable-like workpiece having a connector, a branching portion, etc. The plurality of workpieces are linear parts randomly piled up in a box or on a plane, etc.

[0010] The workpiece removal device 1 according to this embodiment includes a robot arm 2, a control device 3, and a three-dimensional vision sensor 4.

[0011] The robot arm 2 is a specific example of a gripping means. The robot arm 2 is configured as a multi-joint arm having, for example, a plurality of links 21, joints (wrist joints, elbow joints, shoulder joints, etc.) 22 that rotatably connect the links 21, and an end effector 23 provided at the tip of the links 21 and gripping a workpiece.

[0012] Each joint 22 is provided with a rotation sensor such as an encoder that detects rotation information of the joint 22, an actuator such as a servo motor that drives the joint 22, and a force sensor that detects the operating force of the joint 22. The force sensor is, for example, a torque sensor that detects the torque of the joint 22. Each joint 22 is provided with a reduction mechanism, etc.

[0013] The end effector 23 has, for example, a plurality of fingers. The fingers are provided with joints, actuators, etc., and each finger is configured to be able to grip a workpiece.

[0014] The control device 3 performs various arithmetic processing and control processing for the robot arm 2. The control device 3 has a hardware configuration of a normal computer including, for example, a processor 3a such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), an internal memory 3b such as a RAM (Random Access Memory) or a ROM (Read Only Memory), a storage device 3c such as an HDD (Hard Disk Drive) or an SDD (Solid State Drive), an input / output I / F 3d for connecting peripheral devices such as a display, and a communication I / F 3e for communicating with devices outside the device.

[0015] The three-dimensional vision sensor 4 is a specific example of an acquisition means. The three-dimensional vision sensor 4 acquires three-dimensional information of a plurality of workpieces. The three-dimensional information of the workpieces includes information on the shape, position (three-dimensional coordinates, etc.), and posture of each workpiece.

[0016] The three-dimensional vision sensor 4 is provided, for example, on the end effector 23 or link 21 of the robot arm 2. The three-dimensional vision sensor 4 is composed of a camera, a laser sensor, etc. The three-dimensional vision sensor 4 outputs the acquired three-dimensional information of the workpiece to the control device 3.

[0017] 2 is a block diagram showing a schematic system configuration of the control device according to this embodiment. The control device 3 according to this embodiment includes a candidate calculation unit 31 and a robot control unit 32.

[0018] The candidate calculation unit 31 calculates at least one candidate gripping point that is a candidate for the gripping point of the workpiece when the end effector 23 of the robot arm 2 grips the workpiece, based on the three-dimensional information of the workpiece acquired by the three-dimensional vision sensor 4.

[0019] For example, the candidate calculation unit 31 calculates depth information indicating the height position of each workpiece based on the three-dimensional information of the workpiece acquired by the three-dimensional vision sensor 4. The candidate calculation unit 31 detects a convex portion protruding in the height direction based on the calculated depth information of each workpiece.

[0020] The candidate calculation unit 31 performs binarization based on the calculated depth information, for example, by setting points at or above a predetermined height as 1 and points below the predetermined height as 0, and detects points that are 1 as convex parts. The candidate calculation unit 31 may set the convex parts detected as described above as gripping candidate points. This allows convex parts that are easy to grip by the end effector 23 to be gripping candidate points.

[0021] The candidate calculation unit 31 outputs the plurality of gripping candidate points calculated as described above to the robot control unit 32.

[0022] The robot control unit 32 is a specific example of a control means. The robot control unit 32 controls the operation of the robot arm 2. For example, the robot control unit 32 performs feedback control of the robot arm 2 by controlling the actuators of each joint based on rotation information (rotation angle, etc.) from a rotation sensor of each joint and an operating force from a force sensor. This allows the end effector 23 of the robot arm 2 to be moved to a desired position.

[0023] The robot control unit 32 controls the actuators of the fingers of the end effector 23 to control gripping and release of the workpiece by the end effector 23. In this way, the robot control unit 32 can control the robot arm 2 to grip and move the workpiece.

[0024] The robot control unit 32 may select one gripping candidate point from the multiple gripping candidate points calculated by the candidate calculation unit 31. Based on the three-dimensional information of the workpiece acquired by the three-dimensional vision sensor 4, the robot control unit 32 controls the robot arm 2 so that the end effector 23 of the robot arm 2 grips the workpiece at the gripping candidate point.

[0025] However, when a conventional workpiece unloading device grips a linear workpiece, there is a risk of failure to grip the workpiece, such as gripping multiple workpieces at the same time, for example, because the workpieces may become entangled with each other.

[0026] In contrast, the workpiece extraction device 1 according to this embodiment controls the robot arm 2 so that, after the end effector 23 of the robot arm 2 grips a workpiece, the workpiece gripped by the end effector 23 traces a circular trajectory. Note that, by controlling the robot arm 2 so that the end effector 23 of the robot arm 2 traces a circular trajectory, the workpiece gripped by the end effector 23 also traces a circular trajectory as described above.

[0027] The workpiece removal device 1, for example, controls the robot arm 2 so that the end effector 23 of the robot arm 2 grasps the workpiece and lifts it up to a predetermined height, and then the robot arm 2 is controlled so that the workpiece grasped by the end effector 23 moves in a circular trajectory.

[0028] For example, linear workpieces such as cables are often wound in a circle. Therefore, by rotating the workpiece from the outside in a circular orbit as if to untie the circle, the entanglement of the workpieces can be easily untangled. This reduces the chance of the workpiece failing to be grasped and allows the workpiece to be removed reliably.

[0029] The circular trajectory may include not only a perfect circle but also an ellipse. Furthermore, the robot control unit 32 may control the robot arm 2 so that the workpiece gripped by the end effector 23 of the robot arm 2 draws a rectangular trajectory.

[0030] The robot control unit 32 may control the robot arm 2 so that after the robot arm 2 grips the workpiece, the workpiece gripped by the robot arm 2 rotates while revolving around a circular orbit. This makes it easier to untangle the entangled workpieces by the revolution and rotation of the workpieces.

[0031] The robot control unit 32 may control the robot arm 2 so that after the robot arm 2 grips the workpiece, the workpiece gripped by the robot arm 2 revolves in a circular orbit and vibrates the workpiece gripped by the robot arm 2. This makes it easier to disentangle the entangled workpieces by the revolution and vibration of the workpieces.

[0032] For example, a vibrator that generates the vibration may be provided in the end effector 23 of the robot arm 2. The magnitude of the vibration is preferably set according to the size of a portion where entanglement of workpieces is likely to occur, such as a connector or a branching portion.

[0033] When the robot control unit 32 determines that the torque detected by the torque sensor is equal to or greater than a predetermined value, it may control the robot arm 2 so that the workpiece grasped by the robot arm 2 revolves in a circular orbit and the workpiece grasped by the robot arm 2 is vibrated by a vibrator.

[0034] The torque sensor is a specific example of the torque detection means. The torque sensor is provided, for example, in the end effector 23 of the robot arm 2. The torque sensor detects the rotational torque when the workpiece moves in a circular orbit. When the workpieces held by the robot arm 2 are revolved in a circular orbit, if the workpieces are tightly entangled, the torque value of the torque sensor becomes high and exceeds a predetermined value. At this timing, the workpieces held by the robot arm 2 are vibrated by a vibrator, so that the tight entanglement between the workpieces can be more easily undone.

[0035] The robot control unit 32 may control the robot arm 2 so that the workpiece held by the robot arm 2 rotates while revolving around a circular orbit and vibrates the workpiece held by the robot arm 2. This makes it easier to untangle the entangled workpieces by the revolution, rotation and vibration of the workpieces.

[0036] The robot control unit 32 may control the robot arm 2 so that the workpiece gripped by the end effector 23 of the robot arm 2 reciprocates in a circular trajectory.

[0037] Next, a workpiece picking method according to this embodiment will be described with reference to Fig. 3, which is a flowchart showing the flow of the workpiece picking method according to this embodiment.

[0038] The three-dimensional vision sensor 4 acquires three-dimensional information of a plurality of workpieces, and outputs the acquired three-dimensional information of the workpieces to the control device 3 (step S101).

[0039] The candidate calculation unit 31 of the control device 3 calculates gripping candidate points of the workpiece when the end effector 23 of the robot arm 2 grips the workpiece, based on the three-dimensional information of the workpiece acquired by the three-dimensional vision sensor 4 (step S102). The candidate calculation unit 31 outputs the calculated gripping candidate points to the robot control unit 32.

[0040] The robot control unit 32 controls the robot arm 2 so that the end effector 23 of the robot arm 2 grasps and lifts the workpiece at the grasping candidate point, based on the three-dimensional information of the workpiece acquired by the three-dimensional vision sensor 4 (step S103).

[0041] The robot control unit 32 controls the robot arm 2 so that the workpiece gripped by the end effector 23 of the robot arm 2 moves in a circular trajectory (step S104).

[0042] As described above, the workpiece removal device 1 according to this embodiment controls the robot arm 2 so that after the robot arm 2 grips a workpiece, the workpiece gripped by the robot arm 2 moves in a circular trajectory. This makes it possible to easily untangle the workpieces, suppress failure to grip the workpieces, and reliably remove the workpieces.

[0043] EMBODIMENT 2 4 is a block diagram showing a schematic system configuration of the control device according to this embodiment. The control device 30 according to this embodiment further includes a success / failure determination unit 33 that determines whether the robot arm 2 has successfully grasped the workpiece.

[0044] The robot control unit 32 controls the robot arm 2 so that the workpiece gripped by the robot arm 2 traces a circular trajectory only when it is determined by the success / failure determination unit 33 that gripping of the workpiece has failed. As a result, the operation of tracing the circular trajectory of the workpiece is performed only when it is determined that gripping of the workpiece has failed, and therefore, only the minimum necessary operation is required.

[0045] The success / failure determination unit 33 is a specific example of a determination means. When a workpiece is gripped by the robot arm 2, the success / failure determination unit 33 determines whether or not the gripping of the workpiece was successful. For example, after the workpiece is gripped by the robot arm 2 and lifted up to a predetermined height, the success / failure determination unit 33 determines whether or not the gripping of the workpiece was successful.

[0046] The success / failure determination unit 33 determines that gripping of the workpiece has failed when the end effector 23 of the robot arm 2 grips multiple (two or more) workpieces simultaneously. Note that the success / failure determination unit 33 may determine that gripping of the workpiece has failed when the end effector 23 of the robot arm 2 grips zero workpieces, that is, when the end effector 23 is unable to grip the workpieces. In particular, as described above, when gripping linear workpieces, the workpieces are likely to become entangled with each other, resulting in failure to grip multiple workpieces simultaneously, and it is necessary to reliably determine this failure.

[0047] For example, a force sensor 5 is provided between the link tip side of the robot arm 2 and the end effector 23. When the end effector 23 grips a workpiece, the weight of the workpiece is applied to the end effector 23. The force sensor 5 detects the weight of the workpiece.

[0048] The success / failure determination unit 33 may determine whether or not the workpiece has been successfully gripped, based on the weight of the workpiece detected by the force sensor 5. The weight of the workpiece may be set in advance in the success / failure determination unit 33. Based on the weight of the workpiece detected by the force sensor 5, the success / failure determination unit 33 determines that gripping of the workpiece has failed when the end effector 23 of the robot arm 2 grips multiple workpieces simultaneously, when zero workpieces have been gripped, or when the workpiece cannot be lifted.

[0049] The success / failure determination unit 33 may determine whether or not the workpiece has been successfully gripped based on the weight of the workpiece detected by the torque sensor. The success / failure determination unit 33 may determine whether or not the workpiece has been successfully gripped based on an image of the workpiece captured by a camera. The success / failure determination unit 33 outputs the result of the determination of whether or not the workpiece has been successfully gripped, determined as described above, to the robot control unit 32.

[0050] As described above, when the success / failure determination unit 33 determines that gripping of the workpiece has failed, the robot control unit 32 controls the robot arm 2 so that the workpiece gripped by the robot arm 2 follows a circular trajectory.

[0051] Furthermore, after the workpiece grasped by the robot arm 2 has been controlled to trace a circular trajectory, the success / failure determination unit 33 may again determine whether the robot arm 2 has successfully grasped the workpiece. Then, the robot control unit 32 may control the robot arm 2 so that the workpiece grasped by the robot arm 2 traces a circular trajectory, according to the determination result by the success / failure determination unit 33. This makes it possible to more reliably untangle the workpieces and more reliably prevent failure to grasp the workpiece.

[0052] EMBODIMENT 3 In this embodiment, the robot control unit 32 may calculate a distance d from a gripping point where the robot arm 2 grips the workpiece to a maximum height position of the multiple linear workpieces based on three-dimensional information of the multiple linear workpieces acquired by the three-dimensional vision sensor, as shown in Fig. 5. The robot control unit 32 may determine the operation of the workpiece after the robot control unit 32 grips the workpiece based on the calculated distance d.

[0053] The greater the distance d from the gripping point of the workpiece to the maximum height position of the workpiece, the greater the possibility that the workpiece at that gripping point is strongly entangled with other workpieces. Therefore, by determining the operation of the workpieces taking into account the distance d that reflects the entanglement, the entanglement between the workpieces can be more effectively resolved.

[0054] It is preferable that the robot control unit 32 increases the amount of movement of the workpiece as the distance d from the gripping point of the workpiece to the maximum height position of the workpiece increases. In this way, when the distance d from the gripping point of the workpiece to the maximum height position of the workpiece is large and the entanglement is high, the amount of movement of the workpiece is increased, so that the entanglement of the workpieces can be more reliably undone.

[0055] For example, the distance d from the gripping point of the workpiece to the maximum height position of the workpiece is divided into six levels, from (1) to (6), which increase in level from (1) to (6). (1) has the shortest distance d, the lowest level of entanglement, and (6) has the longest distance d, the highest level of entanglement.

[0056] The movements of the workpiece are associated in advance with the levels (1) to (6), for example, as shown in Fig. 6. The amount of movement of the workpiece gradually increases in the order from (1) to (6). Although the workpiece is rotated clockwise in Fig. 6, it may be rotated counterclockwise. The range of levels (1) to (6) is set to an optimum value previously obtained through experiments.

[0057] When the robot control unit 32 determines that the distance d from the gripping point of the workpiece to the maximum height position of the workpiece is within the range of level (1), the robot arm 2 is controlled so that after gripping and lifting the workpiece, the robot arm 2 lifts the workpiece gripped by the robot arm 2 straight up.

[0058] When the robot control unit 32 determines that the distance d from the gripping point of the workpiece to the maximum height position of the workpiece is within the range of level (2), the robot arm 2 grips and lifts the workpiece, and then controls the robot arm 2 so that the workpiece gripped by the robot arm 2 revolves half a revolution in a circular orbit.

[0059] When the robot control unit 32 determines that the distance d from the gripping point of the workpiece to the maximum height position of the workpiece is within the range of level (3), the robot arm 2 grips and lifts the workpiece, and then controls the robot arm 2 so that the workpiece gripped by the robot arm 2 rotates once while revolving half a revolution in a circular orbit.

[0060] When the robot control unit 32 determines that the distance d from the gripping point of the workpiece to the maximum height position of the workpiece is within the range of level (4), the robot arm 2 grips and lifts the workpiece, and then controls the robot arm 2 so that the workpiece gripped by the robot arm 2 revolves around a circular orbit once.

[0061] When the robot control unit 32 determines that the distance d from the gripping point of the workpiece to the maximum height position of the workpiece is within the range of level (5), the robot arm 2 grips and lifts the workpiece, and then controls the robot arm 2 so that the workpiece gripped by the robot arm 2 revolves once around a circular orbit while rotating once on its own axis.

[0062] When the robot control unit 32 determines that the distance d from the gripping point of the workpiece to the maximum height position of the workpiece is within the range of level (6), the robot arm 2 controls the robot arm 2 so that after the robot arm 2 grips and lifts the workpiece, the workpiece gripped by the robot arm 2 revolves around a circular orbit only two times.

[0063] The association information that associates the distance d from the gripping point of the workpiece to the maximum height position of the workpiece with the motion of the workpiece as described above may be set in advance in the robot control unit 32 or the like.

[0064] The robot control unit 32 may use a learning device to determine the behavior of the workpiece after the robot control unit 32 grasps the workpiece. The learning device learns the correspondence between a plurality of linear workpiece images acquired by a camera or the like and the behavior of the workpiece after the robot control unit 32 grasps the workpiece. Then, the robot control unit 32 may input an image of the workpiece including a grasping point to the learned learning device, and determine the behavior of the workpiece after the robot control unit 32 grasps the workpiece based on the result output from the learning device.

[0065] The learning device is composed of a neural network such as a recurrent neural network (RNN). The RNN may have a long short-term memory (LSTM) in an intermediate layer. Instead of a neural network, the learning device may be composed of another learning device such as a support vector machine (SVM).

[0066] If the success / failure determination unit 33 determines that gripping of the workpiece has failed, the robot control unit 32 may calculate the distance d from the gripping point of the workpiece to the maximum height position of the workpiece, and determine the operation of the workpiece after the robot control unit 32 grips the workpiece based on the calculated distance d.

[0067] Fig. 7 is a flow chart showing the flow of the workpiece picking method according to the embodiment. As shown in Fig. 8(a), the 3D vision sensor 4 acquires 3D information of a plurality of workpieces, and outputs the acquired 3D information of the workpieces to the control device 3 (step S201).

[0068] The candidate calculation unit 31 of the control device 3 calculates gripping candidate points of the workpiece when the end effector 23 of the robot arm 2 grips the workpiece, based on the three-dimensional information of the workpiece acquired by the three-dimensional vision sensor 4 (step S202). The candidate calculation unit 31 outputs the calculated gripping candidate points to the robot control unit 32.

[0069] The robot control unit 32 controls the robot arm 2 so that the end effector 23 of the robot arm 2 grasps and lifts the workpiece at the grasping candidate point, based on the three-dimensional information of the workpiece acquired by the three-dimensional vision sensor 4 (step S203).

[0070] As shown in FIG. 8(b), the success / failure determination unit 33 determines whether or not the workpiece has been successfully gripped based on the weight of the workpiece detected by the force sensor 5 (step S204).

[0071] If the success / failure determination unit 33 determines that gripping of the workpiece has failed due to the above-mentioned multiple workpiece gripping (NO in step S204), the robot control unit 32 calculates the distance from the gripping point of the workpiece to the maximum height position of the workpiece based on the three-dimensional information of the multiple workpieces acquired by the three-dimensional vision sensor 4 (step S205).

[0072] As shown in FIG. 8(c), the robot control unit 32 determines the movement of the workpiece based on the calculated distance and the correspondence information, controls the robot arm 2 so that the workpiece performs that movement (step S206), and returns to the processing described above (step S204).

[0073] If the success / failure determination unit 33 determines that the workpiece has been successfully grasped by grasping the multiple workpieces as shown in FIG. 8(d) (YES in step S204), the robot control unit 32 controls the robot arm 2 to move the workpiece to the desired position (step S207).

[0074] If the success / failure determination unit 33 determines that the gripping of the workpieces has failed due to gripping of zero workpieces (NO in step S204), the process may return to the above process (step S201).

[0075] EMBODIMENT 4 Fig. 9 is a block diagram showing a schematic system configuration of the control device according to this embodiment. A linear workpiece such as a cable may be arranged in a wound state, for example. In response to this, the control device 40 according to this embodiment further includes a radius information acquisition unit 34 that acquires information on the radius of the workpiece in the wound state.

[0076] The radius information acquiring unit 34 is a specific example of a radius information acquiring means. The radius information acquiring unit 34 calculates the radius of the workpiece based on, for example, an image of the workpiece acquired by the 3D vision sensor 4. Information on the radius of the workpiece may be input to the radius information acquiring unit 34, or may be set in the radius information acquiring unit 34 in advance.

[0077] The robot control unit 32 determines the radius of the circular trajectory of the workpiece gripped by the robot arm 2 based on the information on the radius of the workpiece acquired by the radius information acquisition unit 34. The robot control unit 32 controls the robot arm 2 so that the workpiece describes a circular trajectory with the determined radius. This makes it possible to set an optimal size of the circular trajectory of the workpiece according to the size of the radius of the linear workpiece arranged in a wound state, thereby making it possible to more effectively untangle the workpieces from each other.

[0078] It is preferable that the robot control unit 32 enlarges the circular trajectory of the workpiece gripped by the robot arm 2 as the radius of the workpiece acquired by the radius information acquisition unit 34 increases.

[0079] 10, the radius Ra of the cable A is larger than the radius Rb of the cable B. Therefore, the robot control unit 32 determines the circular trajectory Sa of the cable A to be larger than the circular trajectory Sb of the cable B.

[0080] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims.

[0081] The present invention can also be implemented by causing a processor to execute a computer program to perform the processes shown in FIGS.

[0082] The program can be stored and provided to a computer using various types of non-transitory computer readable media. The non-transitory computer readable media includes various types of tangible storage media. Examples of the non-transitory computer readable media include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / Ws, and semiconductor memories (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, and RAMs (random access memories)).

[0083] The program may be provided to the computer by various types of transitory computer readable media. Examples of the transitory computer readable medium include an electric signal, an optical signal, and an electromagnetic wave. The transitory computer readable medium can provide the program to the computer via a wired communication path such as an electric wire and an optical fiber, or via a wireless communication path.

[0084] Each unit constituting the control device 3 according to each of the above-mentioned embodiments can be realized not only by a program, but also in whole or in part by dedicated hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). [Explanation of symbols]

[0085] 1 Workpiece removal device, 2 Robot arm, 3 Control device, 4 Three-dimensional vision sensor, 5 Force sensor, 21 Link, 22 Joint, 23 End effector, 30 Control device, 31 Candidate calculation unit, 32 Robot control unit, 33 Success / failure determination unit, 34 Radius information acquisition unit, 40 Control device

Claims

1. A workpiece removal device that removes workpieces one by one from a plurality of linear workpieces placed in a three-dimensional space, A gripping means for gripping the workpiece; a control means for controlling the gripping means so that the workpiece gripped by the gripping means moves along a circular or rectangular trajectory after the gripping means grips the workpiece; Equipped with The control means controls the gripping means so that the workpiece gripped by the gripping means revolves around a circular or rectangular orbit and at least one of the following is performed: the workpiece gripped by the gripping means is rotated on its axis; and the workpiece gripped by the gripping means is vibrated. Work removal device.

2. The workpiece removal device according to claim 1, The gripping means further includes a determination means for determining whether the gripping means has successfully gripped the workpiece, The control means controls the gripping means so that the workpiece gripped by the gripping means moves in a circular or rectangular trajectory only when the determination means determines that gripping of the workpiece has failed. Work removal device.

3. The workpiece removal device according to claim 2, The determination means determines again whether the gripping means has successfully gripped the workpiece after the gripping means has controlled the workpiece to move along a circular trajectory, The control means controls the gripping means so that the workpiece gripped by the gripping means moves in a circular or rectangular trajectory according to the determination result by the determination means. Work removal device.

4. The workpiece removal device according to any one of claims 1 to 3, Further, a torque detection means is provided for detecting a torque when the workpiece moves in a circular or rectangular trajectory, When the control means determines that the torque detected by the torque detection means is equal to or greater than a predetermined value, the control means controls the gripping means so that the workpiece gripped by the gripping means moves in a circular or rectangular trajectory and vibrates the workpiece gripped by the gripping means. Work removal device.

5. The workpiece removal device according to any one of claims 1 to 3, The method further includes acquiring three-dimensional information of the plurality of linear workpieces, The control means Calculating a distance from a gripping point at which the gripping means grips the workpiece to a maximum height position of the plurality of linear workpieces based on the three-dimensional information of the plurality of linear workpieces acquired by the acquisition means; determining an operation of the workpiece after the gripping means grips the workpiece based on the calculated distance; Work removal device.

6. The workpiece removal device according to claim 5, The control means increases the amount of movement of the workpiece as the distance increases. Work removal device.

7. The workpiece removal device according to any one of claims 1 to 3, The plurality of linear workpieces in the three-dimensional space are arranged in a wound state, Further comprising a radius information acquisition means for acquiring information on the radius of the workpiece in the wound state, The control means determines a radius of a circular trajectory of the workpiece gripped by the gripping means based on the information on the radius of the workpiece acquired by the radius information acquisition means, and controls the gripping means based on the determined radius so that the workpiece describes a circular trajectory. Work removal device.

8. A method for removing workpieces one by one from a plurality of linear workpieces placed in a three-dimensional space, comprising the steps of: A step of gripping the workpiece by a gripping means; After gripping the workpiece, moving the gripped workpiece so that the gripped workpiece describes a circular or rectangular trajectory; Including, The gripping means is controlled so that the workpiece gripped by the gripping means revolves around a circular or rectangular orbit and at least one of the following is performed: the workpiece gripped by the gripping means is rotated on its axis; and the workpiece gripped by the gripping means is vibrated. How to remove the workpiece.

9. A process of gripping each of a plurality of linear workpieces placed in a three-dimensional space by a gripping means; A process of moving the gripped workpiece so that the gripped workpiece describes a circular or rectangular trajectory after the gripping means grips the workpiece; A process of controlling the gripping means so that the workpiece gripped by the gripping means revolves around a circular or rectangular orbit and at least one of rotating the workpiece gripped by the gripping means and vibrating the workpiece gripped by the gripping means is performed; to cause a computer to execute program.

10. A control device that controls the picking out of a plurality of linear workpieces placed in a three-dimensional space one by one, After the gripping means grips the workpiece, the gripping means is controlled so that the workpiece gripped by the gripping means moves along a circular or rectangular trajectory; The gripping means is controlled so that the workpiece gripped by the gripping means revolves around a circular or rectangular orbit and at least one of the following is performed: the workpiece gripped by the gripping means is rotated on its axis; and the workpiece gripped by the gripping means is vibrated. Control device.

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