Pickup system

Abstract

A workpiece posture calculation section (4) calculates the posture of a workpiece (90) from image data acquired from an imaging section (41), selects a workpiece (90) to be picked up, and determines a holding position and angle. A robot (2) picks up and takes out the selected workpiece (90) in accordance with the determination by the workpiece posture calculation section (4). A posture changing device (3) changes the posture of the workpiece (90) held by the robot (2). A control section causes the workpiece (90) held by the robot (2) to be switched to the posture changing device (3) when the determined holding position and angle deviate from a set holding position and angle, and causes the workpiece (90) to be rotated and then held again by the robot (2) in a manner in which the set holding position and angle are coincident.

Description

Technical Field

[0001] This application relates to a picking system. Background Technology

[0002] In recent years, in response to diversified market demands, there has been a need for component supply systems capable of handling variable production processes. One such system developed is a picking system that uses vision sensors to measure the position of workpieces scattered on pallets or conveyor belts, and then utilizes robots to pick up these workpieces with high precision.

[0003] For example, a picking device is disclosed that uses vision sensors mounted on the upper part of the scattered pile of workpieces and the end effector of a robot to detect the posture and orientation of the scattered pile of workpieces, identify workpieces that can be picked up, and pick up the workpieces (see, for example, Patent Document 1). Alternatively, a temporary placement device is disclosed that has a deformable mounting surface formed of sheet material to uniformly orient the workpieces (see, for example, Patent Document 2).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-124450 (paragraphs 0016-0043) Figure 1 (Figure 6)

[0007] Patent Document 2: Japanese Patent Application Publication No. 2017-80846 (paragraphs 0016-0057) Figure 1 (Figure 8) Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, even if workpieces that can be held can be selected by simply detecting their posture and orientation, it is difficult to remove workpieces that cannot be held. Furthermore, when the shape of the mounting surface is deformed, the orientation may not become the desired direction. When the workpiece's posture cannot be changed to an appropriate state, multiple deformations are required, resulting in unpredictable processing time and reliability issues.

[0010] This application discloses a technology for solving the above-mentioned problems, with the aim of obtaining a pick-up system that can reliably hold a workpiece in an appropriate posture.

[0011] Methods for solving problems

[0012] The pickup system disclosed in this application is characterized by comprising: a workpiece posture calculation unit having a camera unit for capturing images of randomly stacked workpieces, calculating the posture of each workpiece based on the image data obtained from the camera unit, selecting the workpiece to be picked up, and determining the gripping position and angle; a robot that grips and removes the selected workpiece according to the determination of the workpiece posture calculation unit; a posture changing device having a chuck and a rotating unit for rotating the chuck, changing the posture of the component gripped by the chuck; and a control unit that, when the determined gripping position and angle deviate from the set gripping position and angle, causes the workpiece gripped by the robot to be transferred to the posture changing device, and causes the workpiece to rotate so that the robot grips it again in a manner consistent with the set gripping position and angle.

[0013] Invention Effects

[0014] According to the picking system disclosed in this application, the system is configured to change the angle of a workpiece supplied in an uneven posture to a desired angle, thereby reliably holding the workpiece in an appropriate posture. Attached Figure Description

[0015] [ Figure 1 [Illustration 1] is a schematic diagram illustrating the structure of the pickup system in Embodiment 1.

[0016] [Figure 2] Figures 2A and 2B are side views illustrating the structure of gripping claws with different shapes at the end of the robot arm assembled in the picking system of Embodiment 1.

[0017] [Figure 3] Figures 3A to 3C are side views illustrating the structure of the picking objects, i.e., workpieces with different shapes, of the picking system in Embodiment 1.

[0018] [Figure 4] Figures 4A, 4B and 4C are side views used to illustrate the envisioned holding posture for a rod-shaped workpiece in the picking system of Embodiment 1, the state of the workpiece stacked in an unexpected posture, and the state of holding the workpiece in an unexpected posture, respectively.

[0019] [Figure 5] Figures 5A, 5B, 5C and 5D are side views illustrating the following: the gripping posture of a stepped workpiece in the picking system of Embodiment 1; the state of a workpiece stacked in a first unexpected posture; the state of gripping a workpiece in a first unexpected posture; and the state of a robot hand gripping a workpiece stacked in a second unexpected posture.

[0020] [Figure 6] Figures 6A, 6B and 6C are side views showing the envisioned holding posture for an L-shaped workpiece in the picking system of Embodiment 1, the state of the workpiece stacked in the envisioned posture, and the state of the workpiece stacked in an unexpected posture, respectively.

[0021] [Figure 7] Figures 7A and 7B are schematic side views illustrating the state in which two types of workpieces in the pick-up target workpiece of the pick-up system of Embodiment 1 are scattered and piled up in the workpiece loading device.

[0022] [Figure 8] Figures 8A to 8F are schematic diagrams illustrating a general approach to dealing with a situation where a workpiece is placed in an unintended position on a workpiece mounting device.

[0023] [ Figure 9 [ ] is a flowchart illustrating the operation of the picking system in Implementation 1.

[0024] [Fig. 10] Figs. 10A to 10D are perspective views showing the movement of the robot arm and posture changing device at each stage of the change of the workpiece held in an unexpected posture to an expected posture in the picking system of Embodiment 1.

[0025] [Fig. 11] Fig. 11A and Fig. 11B are schematic side views illustrating the motion of the robot arm and the posture changing device for changing the posture of the workpiece in the picking system of Embodiment 1 and the picking system of the third variation, respectively.

[0026] [Fig. 12] Fig. 12A to Fig. 12C are side views illustrating the areas set for determining the gripping positions of the pick-up objects, i.e., workpieces of different shapes, for the pick-up system of Embodiment 1.

[0027] [ Figure 13 [Illustration 1] is a schematic diagram illustrating the structure of the picking system in the first modified example of Embodiment 1.

[0028] [ Figure 14 [Illustration 1] is a schematic diagram illustrating the structure of the pickup system in the second variation of Embodiment 1.

[0029] [ Figure 15 [ ] is a schematic diagram illustrating the structure of the pickup system in the third variation of Embodiment 1.

[0030] [ Figure 16 [ ] is a block diagram illustrating a structural example of the part of the picking system that performs arithmetic processing according to Embodiment 1.

[0031] [ Figure 17 [Illustration 1] is a schematic diagram illustrating the structure of the pickup system in Embodiment 2.

[0032] [ Figure 18 [ ] is a flowchart illustrating the operation of the picking system in Embodiment 2.

[0033] [ Figure 19[Illustration 1] is a schematic diagram illustrating the structure of the pickup system in Embodiment 3.

[0034] [ Figure 20 [ ] is a flowchart illustrating the operation of the picking system in Embodiment 3. Detailed Implementation

[0035] Implementation Method 1

[0036] Figure 1-Figure 2 2C is used to explain the structure and operation of the pickup system in Implementation Method 1. Figure 1 Figure 2A and Figure 2B are side views illustrating the overall structure of the picking system. Figure 2A and Figure 2B are side views illustrating the structure of the gripping claws with different shapes that are assembled at the end of the robot arm to correspond to the shape of the workpiece. Figure 3A, Figure 3B and Figure 3C are side views illustrating the structure of different picking objects, i.e. workpieces, such as rod-shaped, stepped, and L-shaped objects.

[0037] Figures 4A, 4B, and 4C are side views illustrating the longitudinal gripping posture of the rod-shaped workpiece corresponding to Figure 3A, the state of the workpiece stacked in an unexpected horizontal position, and the state of the workpiece being gripped in a horizontal position, respectively. Furthermore, Figures 5A, 5B, 5C, and 5D are side views illustrating the gripping posture of the gripping head of the stepped-shaped workpiece corresponding to Figure 3B, the state of the workpiece stacked in a first unexpected posture with the head at the bottom, the state of the workpiece being gripped in a posture with the head at the bottom, and the state of the robot hand gripping the workpiece stacked in a second unexpected horizontal position, respectively.

[0038] In addition, Figures 6A, 6B and 6C are schematic side views showing, together with the robot hand, the holding posture of the workpiece with the short side of the L-shaped workpiece corresponding to Figure 3C, the state of the workpiece stacked with the short side facing upwards, and the state of the workpiece stacked with the short side facing downwards in an unconventional posture.

[0039] Furthermore, Figures 7A and 7B are schematic side views showing the state of the stepped workpiece corresponding to Figure 3B and the L-shaped workpiece corresponding to Figure 3C, which are randomly piled up in the workpiece loading device, together with the robot arm. Furthermore, Figures 8A to 8F are schematic diagrams illustrating the general response when a workpiece of the shape shown in Figure 3C is loaded in a non-intended posture. Figures 8A and 8B are side views and perspective views showing the state of a workpiece in a certain posture. Figures 8C and 8D are side views and perspective views showing the state when a workpiece in a certain posture is removed from that posture. Figures 8E and 8F are perspective views showing the state after changing the posture.

[0040] and, Figure 9 This is a flowchart illustrating the operation of the picking system. Figures 10A to 10D are perspective views showing the movement of the robot arm and attitude change device in each of the four stages of the attitude change operation, which changes the workpiece held in an unexpected posture to the expected posture. Furthermore, Figure 11A is a schematic side view illustrating the movement of the robot arm and attitude change device in position and orientation as described in Figures 10A to 10D, and Figure 11B is a schematic side view illustrating the movement of the robot arm and attitude change device in the picking system of the third variation, corresponding to that in Figure 11A.

[0041] Furthermore, Figures 12A to 12C are side views illustrating the areas set up to determine the gripping position for workpieces with shapes different from those corresponding to those in Figures 3A to 3C. Hereinafter, Embodiment 1 will be described in detail with reference to the accompanying drawings. In the following drawings, the same or equivalent parts will be labeled with the same reference numerals and their descriptions will be omitted.

[0042] The picking system of this application is a system for a robot to pick up randomly stacked workpieces and embed them into a product. Therefore, as Figure 1 As shown, the picking system 1 includes a robot 2 that selects and picks up a workpiece 90 from a workpiece loading device 6, such as a tray on which multiple workpieces 90 are arranged, and a posture changing device 3 that changes the posture of the held workpiece 90. Furthermore, it includes a workpiece posture calculation unit 4, which has a camera unit 41 capable of acquiring a three-dimensional image of the workpiece 90 in any region, and individually identifies the workpiece 90 based on the camera data of the workpiece 90, and calculates the posture of the identified workpiece 90.

[0043] Regarding robot 2, only one robot arm 21 is depicted. However, robot 2 is a 5-DOF horizontal articulated robot, a 6-DOF vertical articulated robot, or a collaborative robot, and is equipped with multiple robot arms 21, multiple joints, a base, etc. At the end of each robot arm 21 is a flange 21f for mounting a robot hand 22, which is used to grasp the workpiece 90. Furthermore, a robot control unit 23 is provided, which controls the movements of each part based on information representing the orientation of the workpiece 90 received from the workpiece orientation calculation unit 4.

[0044] The robot hand 22 is connected to the flange 21f of the robot arm 21 and is used as a tool for picking up workpiece 90. The position and movement of the robot hand 22 are controlled by the robot control unit 23. The robot hand 22 grasps the workpiece 90 according to the control commands of the robot control unit 23. As shown in Figures 2A and 2B, a gripping claw 22c corresponding to the shape of the workpiece 90 is detachably mounted at the end of the robot hand 22.

[0045] The shape of the gripping jaw 22c can be a dedicated shape corresponding to the shape of the workpiece 90 taken out from a scattered stacked state, or it can handle various shapes of workpiece 90, allowing for free design. Furthermore, in Figure 1 In the present invention, a rectangular workpiece 90 is conceived for depiction. However, Figure 2A shows a gripping claw 22c for gripping the workpiece 90 with a circular gripping surface, and Figure 2B shows a gripping claw 22c for gripping the planar portion of the workpiece 90.

[0046] The camera unit 41 measures multiple workpieces 90 arranged in the workpiece mounting device 6 in three dimensions, acquiring data (camera data) related to the position and orientation of the workpieces 90 within the workpiece mounting device 6. The camera unit 41 is, for example, a three-dimensional vision sensor, consisting of a device capable of acquiring three-dimensional images of workpieces 90 in any area. The workpiece orientation calculation unit 4 performs image processing on the three-dimensional image data acquired by the camera unit 41 and sends the information to the robot control unit 23 as workpiece position measurement data. The workpiece orientation calculation unit 4 can be arranged near or inside the camera unit 41, or it can be arranged inside or within the housing of the robot control unit 23.

[0047] The camera unit 41 and the workpiece posture calculation unit 4 need to have the function of determining the holding position using the three-dimensional model information of the workpiece 90. That is, it only needs to have the following function: inputting the shape of the workpiece 90 to be picked up as a three-dimensional model into the workpiece posture calculation unit 4 in advance, and determining the holding position based on the image captured by the camera unit 41, accurately identifying the workpiece that can be picked up from the scattered stacked state.

[0048] The workpiece loading device 6 holds a plurality of workpieces 90. The loading state of the workpieces 90 is broadly categorized into a state where they are neatly arranged inside the workpiece loading device 6 and a state of random stacking. Furthermore, in this specification, "random stacking" refers to a state where multiple workpieces 90 are not positioned, or where a workpiece 90 is in contact with at least one other workpiece 90 or the inner wall 6w of the workpiece loading device 6. The workpiece loading device 6 is, for example, a pallet or turnover box for loading workpieces.

[0049] The picking system 1 of this application is characterized by using the posture change device 3 to correctly correct the posture of the workpiece 90. However, before the characteristic description, the problem of picking system that takes scattered stacking as objects will be explained.

[0050] In the picking system 1, various shapes of workpieces are considered as the picking target workpiece 90. For example, if it is a flat bracket, sheet metal, etc., it is classified as a cuboid, rod, etc. workpiece 90 as shown in FIG. 3A. Furthermore, if it is a screw, hex bolt, etc., it is classified as a workpiece 90 with a stepped portion 90s as shown in FIG. 3B. Moreover, if it is a metal plate component with a bent portion, wire formed by bending, L-shaped bracket, etc., it is classified as an L-shaped workpiece 90 with a bent portion 90b as shown in FIG. 3C.

[0051] When workpieces 90 are scattered and piled up, the orientation of the workpiece 90 to be picked up or its overlap with other workpieces 90 can vary greatly. Moreover, depending on the orientation and position of the workpiece 90, sometimes the workpiece 90 to be picked up cannot be retrieved in the desired position and orientation due to interference between the robot arm 22 and the inner wall 6w, ground 6f, or other workpieces 90 of the workpiece loading device 6.

[0052] For example, consider a scenario where the desired orientation is desired for retrieving the cuboid-shaped, rod-like workpiece 90 illustrated in Figure 3A. As shown in Figure 4B, the robot arm 22 contacts the workpiece mounting device 6 in an unconventional orientation, where the workpiece 90 is in contact with the ground 6f of the workpiece mounting device 6 in a horizontal position along its length. As a result, the workpiece 90 cannot be retrieved in the desired orientation and can only be retrieved in an unconventional orientation, as shown in Figure 4C.

[0053] Furthermore, consider the scenario where the head 90t is held in an upward-facing posture (conceptual posture) as shown in Figure 5A, and the workpiece 90 with the stepped portion 90s described in Figure 3B is retrieved. As shown in Figure 5B, if the workpiece 90 is in a first unconceptual posture with the head 90t facing downwards, it can only be retrieved in an unconceptual posture as shown in Figure 5C. Alternatively, as shown in Figure 5D, if the workpiece 90 is placed in a lying posture relative to the ground 6f, it may come into contact with the ground 6f or the inner wall 6w when the robot arm 22 retrieves the workpiece 90, making it impossible to retrieve the workpiece 90 in the conceptual posture shown in Figure 5A.

[0054] Furthermore, consider the scenario where the end of the short side 90g is facing upwards (the hypothetical posture) as shown in Figure 6A, and the L-shaped workpiece 90 with the curved portion 90b described in Figure 3C is grasped and removed. As shown in Figure 6B, when the workpiece 90 is in the hypothetical posture with the end of the short side 90g facing upwards, the workpiece 90 can be grasped and removed at the desired position. However, as shown in Figure 6C, when the workpiece 90 is placed with the short side 90g facing the ground 6f, it may come into contact with the ground 6f or the inner wall 6w when the robot arm 22 removes the workpiece 90, making it impossible to remove the workpiece 90 in the hypothetical posture shown in Figure 6A.

[0055] Furthermore, even when the object workpiece 90 is in the aforementioned envisioned posture, in situations such as Figure 1 In cases of scattered stacking as shown in Figures 7A and 7B, removal becomes even more difficult. Even if the workpiece 90 is in the intended orientation that can be removed, depending on its positional relationship with surrounding workpieces 90, the ground 6f, and the inner wall 6w, the robot arm 22 may sometimes interfere with other surrounding workpieces 90, the ground 6f, and the inner wall 6w. In such cases, it is impossible to remove it in the desired holding position / or orientation.

[0056] In this way, when the workpieces 90 are neatly arranged in the desired posture (ideal posture), the robot can retrieve them in the desired posture without special adjustments. Therefore, the retrieved workpieces 90 can be put into the product without changing their posture. On the other hand, for workpieces 90 that are scattered or not in the desired posture, it is difficult to retrieve them in the desired posture. After retrieval, it is often difficult to put them into the product in their original posture. Therefore, before the workpieces 90 are put into the working area of ​​robot 2, the operator has to manually arrange them neatly on the pallet, increasing the product manufacturing cycle time.

[0057] One solution to this problem is, for example, the following method: a workpiece 90, taken out in a non-intended posture as shown in Figures 8A and 8B, is placed on a temporary placement stage 60. After the posture stabilizes, the robot's posture is changed again, and then the workpiece 90 is taken out. Figures 8A to 8F illustrate the situation of changing the posture of the L-shaped workpiece shown in Figure 3C using the above method.

[0058] When it is desired to remove the workpiece 90 of the shape shown in FIG. 3C in the posture shown in FIG. 6A, and the workpiece 90 is placed in the posture shown in FIG. 6C, the robot arm 22 or gripper 22c interferes with the temporary placement stage 60. Therefore, the workpiece 90 can only be removed in the postures shown in FIG. 8C and FIG. 8D.

[0059] Therefore, the workpiece 90, which is taken out in the postures shown in Figures 8C and 8D, is temporarily placed on the temporary placement table 60 in the states shown in Figures 8A and 8B. In this state, the posture changes as shown in Figure 8E due to tipping caused by the weight of the workpiece 90 itself, tipping caused by vibration if the temporary placement table 60 has a vibration function, or tipping caused by the robot's actions such as the robot hand 22 coming into contact with the workpiece 90.

[0060] The robot is used again to remove the workpiece 90 after its posture change, and it is temporarily placed on the temporary placement table 60 to change its posture. By repeating this action, the posture of the workpiece 90 can be changed to the state shown in Figure 8F. The workpiece 90 in the posture shown in Figure 8F can be removed in the posture shown in Figure 6A, which means that the posture change of the workpiece 90 can be implemented.

[0061] However, in the above method, the repeated picking and placing of workpiece 90 by the robot increases the cycle time required for workpiece orientation changes, which becomes a problem. Furthermore, when the operator manually arranges workpiece 90 neatly on the pallet, completing the orientation change in a single action without workpiece relocation, it can be considered inefficient compared to manual operation.

[0062] Furthermore, when tilting the workpiece 90 placed on the temporary placement platform 60 by its own weight or the vibration of the temporary placement platform 60, the tilting direction is not uniquely determined. Therefore, it is necessary to capture the state of the workpiece 90 using a camera before the robot performs the re-grabbing operation, calculate the removal position, and then use the robot to perform the removal operation. That is, the time spent calculating the posture of the workpiece 90 is required, and a different camera is needed for workpiece removal; therefore, it can be considered a costly posture change method. For the above reasons, from the point of view of time and money, the method of temporarily placing the workpiece 90 on the temporary placement platform 60 to change its posture can be considered not the optimal approach.

[0063] To address this issue, in the picking system 1 of this application, the workpiece 90, which has been picked up in an unexpected posture, is transferred from the robot 2 to the posture changing device 3. The workpiece 90 is then rotated in a manner that allows it to be held in the desired posture, and then the robot 2 holds it again. For example... Figure 1 As shown, the attitude change device 3 includes a switching chuck 31, a gripping jaw 31c mounted at the end of the switching chuck 31, and a rotating part 32 for rotating the switching chuck 31, configured to operate according to the instructions of the workpiece attitude calculation unit 4. Furthermore, it includes a calculation unit (not shown) that calculates the attitude and angle of the workpiece 90 before attitude change and the desired attitude based on the information from the workpiece attitude calculation unit 4.

[0064] The switching chuck 31 accepts a workpiece 90 held by the robot arm 22 in an unexpected posture, and changes the posture of the accepted workpiece 90 to the desired posture before handing it over to the robot arm 22. The rotating part 32 has the following function: when the switching chuck 31, which is mounted at the end of the rotating part 32, accepts a workpiece 90 from the robot 2, it rotates according to the information from the workpiece posture calculation unit 4, changing the orientation of the held workpiece 90 to the desired posture.

[0065] The rotating part 32 is, for example, a servo motor. Based on the calculation results of the arithmetic unit, the rotation amount of the motor is controlled, thereby changing the orientation (angle) of the workpiece 90. The robot arm 22 picks up the workpiece 90 in a scattered, piled-up state; therefore, in most cases, the workpiece 90 is retrieved in an orientation other than the desired one. In contrast, in the picking system 1 of this application, by changing the angle of the switching chuck 31 that receives the workpiece 90 from the robot arm 22, the orientation of the workpiece 90 is changed, and it is handed over to the robot 2, thereby enabling the workpiece 90 to be picked up in the desired orientation.

[0066] The rotating unit 32 can be any device that receives instructions from the robot control unit 23 or the workpiece posture calculation unit 4, controls the rotation of the workpiece 90, and guides the rotation with high precision; it can also be a direct drive motor or the like. Furthermore, any device that includes an encoder capable of measuring the rotation of the rotating unit 32 is acceptable.

[0067] refer to Figure 9 The flowchart and Figure 11A illustrate the operations in the aforementioned pickup system 1. Furthermore, in the following operations, the workpiece posture calculation unit 4 or the robot control unit 23 may also function as a control unit for the collaborative control of the robot 2 and the posture changing device 3; however, a control unit (not shown) may also be provided as an additional system. First, the camera unit 41 captures images of the workpieces 90 scattered on the workpiece placement device 6 (step S100). Then, the workpiece posture calculation unit 4 generates workpiece position and posture data based on the captured images, selects the workpiece 90 as the pickup target, and determines the gripping position (step S110).

[0068] Next, the robot control unit 23 moves the robot arm 22 close to the workpiece 90 determined by the workpiece posture calculation unit 4, and uses the robot arm 22 to grasp a designated portion of the workpiece 90, removing it from the workpiece loading device 6 (step S120). As shown in FIG10A, the robot 2 moves the removed workpiece 90 toward the posture changing device 3 (towards Df) (step S130). Then, when the switching chuck 31 closes the gripping claw 31c to grasp the workpiece 90, the robot 2 opens the gripping claw 22c of the robot arm 22, and as shown in FIG10B, the grasped workpiece 90 is switched to the switching chuck 31 of the posture changing device 3 (step S200).

[0069] Here, a determination is made as to whether the angle of the workpiece 90 after the flipping is required (step S300). In determining whether an angle change is required, information output from the workpiece posture calculation unit 4 or the robot control unit 23 is used. If an angle change is required (step S300: "Yes"), as shown in FIG10C, the rotating unit 32 is rotated in the rotation direction Dr3 to change the angle (step S310), and the determination as to whether an angle change is required is made again (step S300).

[0070] If no angle change is required or the angle becomes such that no angle change is needed (step S300: "No"), a determination is made as to whether a change in gripping position is required (step S400). In determining whether a change in gripping position is required, information output from the workpiece posture calculation unit 4 or the robot control unit 23 is also used. If a change in gripping position is required (step S400: "Yes"), the robot 2 rotates the rotating unit 32 in the tilt direction Da2 of the axis and the rotation direction Dr22 around the axis, moving the gripping claw 22c to the desired gripping position of the workpiece 90, thus changing the gripping position (step S410). Then, the determination as to whether a change in gripping position is required is performed again (step S400).

[0071] If no change in gripping position is required, or if the gripping position does not need to be changed (step S400: "No"), the robot arm 22 grips the workpiece 90. If no change in gripping position is required, the gripping claw 22c is moved to grip the workpiece 90 at the desired position and angle, taking into account the rotation amount of the rotating part 32.

[0072] In this state, when the switching chuck 31 opens the gripping claw 31c and hands the workpiece 90 to the robot 2, as shown in FIG10D, the robot arm 22 moves toward the orientation change device 3 away from the orientation change device 3 and takes the workpiece 90 held by the orientation change device 3. Then, the robot arm 22 puts the workpiece 90 held in the desired position into the product (step S510), thus the picking of the target workpiece 90 ends, and the action from step S100 is repeated toward the next target.

[0073] In addition, Figure 9 The flowchart shows an example of transferring the workpiece 90, which can be held in the desired position, to the attitude change device 3, but it is not limited to this. For example, the angle and holding position of the workpiece 90 can be determined before step S130. If the angle and holding position do not need to be changed, the transfer can be skipped and the process can proceed directly from step S120 to step S510.

[0074] Next, the method for changing the gripping position of the workpiece 90 implemented by the attitude change device 3 will be described using Figures 12A to 12C. Whenever a gripping position change is performed, the workpiece 90 is divided into three regions: region R1, region R2, and region R3. The region where the workpiece 90 is gripped is determined by the picking system 1. Within the workpiece 90, the desired gripping position is assumed to be region R1.

[0075] When the pick-up system 1 of this application holds and retrieves the workpiece 90 at position R1, as shown in Figures 3A and 3B, for the axisymmetric workpiece 90, it is not necessary to use the attitude change device 3 to change the holding position of the workpiece 90. Therefore, by having the switching chuck 31 hold either of the other two regions, and after changing the angle of the component, holding it at the original position again, the angle of the workpiece 90 can be changed.

[0076] On the other hand, when the workpiece 90 is retrieved using either the robot 2's gripping area R2 or area R3, the switching chuck 31 grips the remaining area besides area R1. Then, after changing the angle of the workpiece 90, the robot grips area R1, thereby changing the gripping position of the workpiece 90. For example, when the workpiece 90 is retrieved from the workpiece loading device 6 while gripping area R2, the switching chuck 31 grips area R3, and then the robot grips area R1, thereby picking up the workpiece 90 at the desired position and angle.

[0077] Furthermore, when holding and removing the workpiece 90 at position R1, if the workpiece 90, which has a directional orientation like the L-shape shown in Figure 3C, is held in the posture shown in Figure 6C, the posture changing device 3 is also needed to change the holding direction. In this case, no action can be performed when in contact with a surface such as the ground 6f. However, by switching the chuck 31, the workpiece 90 is held in a floating state, thus allowing it to approach the robot hand 22 from any angle. Therefore, for example, if the workpiece 90 is handed to the posture changing device 3 by adjusting the tilt Da2 so that the axis of the robot hand 22 is horizontal, and the workpiece 90 is received while the rotating part 32 is rotated 180°, the workpiece 90 can be picked up in the desired posture.

[0078] That is, only the workpieces 90 within the workpiece loading device 6 that are currently in the desired posture and do not interfere with surrounding objects are selected for pickup. In contrast, in the pickup system 1 of this application, the posture changing device 3 holds the workpieces 90 in a scattered posture and rotates them. This allows for reliable posture correction by controlling the direction and angle, thus expanding the target range. Specifically, by performing a precise correction in the direction and amount of rotation before switching, the selection of the pickup target workpieces 90 can be expanded and quickly achieved, and reliable correction can be performed, thereby increasing work efficiency.

[0079] <First Variation>

[0080] In the first modification and the second modification described later, regarding the installation of the camera unit, and its use... Figure 1 The examples used to illustrate this are different from those used to illustrate this point. Figure 13It is used to illustrate the structure of the picking system in the first variation. Figure 1 The corresponding diagram, Figure 14 This is used to illustrate the structure of the picking system in the second variation. Figure 1 The corresponding schematic diagram is shown. Furthermore, the structures other than the camera unit and the actions other than those related to the camera unit are the same as those described using Figures 2 to 12C; therefore, the descriptions of the same parts are omitted.

[0081] like Figure 13 As shown, in the first variation of Embodiment 1, the pickup system 1 assembles a camera unit 41 onto the robot arm 21 or robot hand 22 of the robot 2. In this case, the robot control unit 23 pre-teachs the camera position of the workpiece 90 within the workpiece mounting device 6 from above, causing the robot 2 to move and acquire a three-dimensional image of the workpiece 90 via the camera unit 41 mounted at the robot's end effector. The three-dimensional image obtained by the workpiece posture calculation unit 4 is processed to generate workpiece position measurement data, which is then sent to the robot control unit 23.

[0082] The camera unit 41 moves according to the movement of the robot 2, therefore, calculations are needed to convert coordinates and other parameters representing the position of the workpiece 90. However, as the robot arm 22 approaches the workpiece 90, it can capture an image of the workpiece 90 at the closest position, thus enabling a more accurate understanding of the positional relationship between the robot arm 22 and the workpiece 90.

[0083] <Second Variation>

[0084] like Figure 14 As shown, the picking system 1 of the second modification of Embodiment 1 is configured with multiple camera units 41, such as camera unit 41A and camera unit 41B, capable of capturing images of the workpiece mounting device 6 from multiple directions. Camera unit 41A is mounted on the robot arm 22 in the same manner as in the first modification, and camera unit 41B is mounted on the robot arm 22 in the same manner as in the first modification. Figure 1 As described in the text, it is fixedly installed in the space above the workpiece mounting device 6.

[0085] The workpiece posture calculation unit 4 performs image processing on the images captured by the camera units 41A and 41B respectively, and calculates three-dimensional workpiece position measurement data. The calculated workpiece position measurement data is sent to the robot control unit 23 to cause the robot 2 to perform actions. These camera units 41 can all be set above the workpiece mounting device 6, or, depending on the workpiece detection conditions, one can be set above the workpiece mounting device 6 and the other can be set at the end of the robot arm 21, etc.

[0086] Alternatively, two two-dimensional vision sensors can be configured to acquire two-dimensional images of the workpiece 90 from two directions in any region. However, the two-dimensional vision sensors must have the following functions: the shape model data of the workpiece 90 to be picked up must be input into the workpiece posture calculation unit 4 in advance, and the shape of the workpiece 90 must be calculated. In addition, they should have the following functions: using the calculated shape model of the workpiece 90, based on the image captured by the camera unit 41, the workpiece 90 that can be picked up from a scattered pile state can be identified with high precision, and the holding position can be determined.

[0087] <Third Variation>

[0088] In the third variation, regarding the attitude changing device, the direction of the rotation axis and its use... Figure 1 The examples used to illustrate this are different from those used to illustrate this point. Figure 15 It is used to illustrate the structure of the picking system in the third variation. Figure 1 The corresponding schematic diagram. Additionally, the structure and operation of the attitude change device, other than the direction of its rotation axis, are as shown in Figures 2 to 12C or... Figure 13 and Figure 14 The descriptions are the same, so the identical parts of the descriptions are omitted.

[0089] In the picking system 1 of the third variation of embodiment 1, such as Figure 15 As shown, the rotating part 32 of the attitude change device 3 is mounted on the bracket 33, and its rotation axis is set to be parallel to the ground. In this case, the movement of the attitude change device 3, the robot arm 21, and the robot hand 22 is as shown in Figure 11B.

[0090] Furthermore, the rotation axis of the rotating part 32 does not need to be fixed. Figure 1 The vertical or Figure 15 Either of the horizontal planes shown can be appropriately tilted depending on the type and orientation of the workpiece 90. In this case, control is also performed in cooperation with the control of the rotation direction Dr3 using information output from the workpiece orientation calculation unit 4 or the robot control unit 23. Furthermore, the orientation change device 3 can also be constructed using other arms of the robot 2.

[0091] Furthermore, in the pickup system 1 of this application, when the execution unit or control unit for computational processing is constructed using microcomputer software, such as Figure 16As shown, the hardware can also be configured using a microcomputer 800 having a processor 801 and a storage device 802. Although not shown, the storage device 802 includes volatile storage devices such as random access memory and non-volatile auxiliary storage devices such as flash memory. Alternatively, an auxiliary storage device such as a hard disk can be used instead of flash memory. The processor 801 executes a program input from the storage device 802. In this case, the program is input to the processor 801 from the auxiliary storage device via the volatile storage device. Furthermore, the processor 801 can output data such as calculation results to the volatile storage device of the storage device 802, or it can store data in the auxiliary storage device via the volatile storage device.

[0092] Implementation Method 2

[0093] In Embodiment 1 described above, an example of controlling the operation based on data representing the posture of the workpiece on the workpiece mounting device was explained. In this Embodiment 2, compared with Embodiment 1, an example of controlling the operation by also considering data representing the posture of the workpiece on the posture changing device will be described.

[0094] Figure 17 and Figure 18 This is used to illustrate the structure and operation of the picking system in Embodiment 2. Figure 17 This is a schematic diagram used to illustrate the overall structure of the picking system. Figure 18 This is a flowchart illustrating the operation of the picking system. Furthermore, the parts other than the structure and operation related to the data representing the orientation of the workpiece on the attitude changing device are the same as those described in Embodiment 1; therefore, the descriptions of the same parts are omitted, and the descriptions used in Embodiment 1 are referenced. Figure 1 , Figure 9 Other than the diagram.

[0095] like Figure 17 As shown, the pickup system 1 of Embodiment 2 is equipped with a second camera unit 42, which is disposed above or to the side of the switching chuck 31, and is capable of acquiring data indicating the posture and orientation of the workpiece 90 held by the switching chuck. Similar to the camera unit 41, the second camera unit 42 needs to be composed of a device such as a three-dimensional vision sensor capable of acquiring a three-dimensional image of the workpiece 90, or it can be a structure with multiple camera units.

[0096] The second camera unit 42 captures a three-dimensional image of the workpiece 90 after its posture change. The workpiece posture calculation unit 4 performs image processing to generate workpiece position measurement data. Based on this data, the position of the robot 2 is corrected, and the robot arm 22 removes the part from the switching chuck 31. Therefore, compared with the case of Embodiment 1, the part can be picked up with high precision.

[0097] refer to Figure 18The flowchart below explains the operation of the pickup system 1 in Embodiment 2. Furthermore, the steps from capturing images of the workpieces 90 scattered on the workpiece placement device 6 (step S100) to handing the held workpieces 90 over to the changeover chuck 31 (step S200) are the same as in Embodiment 1, and therefore the explanation is omitted.

[0098] When workpiece 90 is handed over from robot 2 to switching chuck 31, a three-dimensional image of workpiece 90 held by switching chuck 31 is captured by second camera unit 42, and image processing is performed on the image by workpiece posture calculation unit 4. Position measurement data representing the posture of workpiece 90 is calculated based on the image processing results of workpiece posture calculation unit 4 (step S210).

[0099] Based on the information output from the workpiece posture calculation unit 4 or the robot control unit 23, the posture data obtained in step S210 is used to determine the necessity of changing the angle and gripping position of the workpiece 90 being handed over, and to implement the change action (steps S300 to S410). The subsequent steps (steps S500 to) are the same as in Embodiment 1.

[0100] Therefore, compared to the case where the orientation of the workpiece 90 is changed based on information related to the rotation amount of the rotating unit 32, the position of the workpiece 90 is detected using data obtained from the second camera unit 42. Thus, compared to the case of Embodiment 1, the workpiece 90 can be picked up with higher precision. The method for changing the gripping position of the workpiece 90 is the same as in Embodiment 1.

[0101] Not only above the chuck 31, the second camera unit 42 can also be configured to capture images of the chuck 31 from the side to generate workpiece position measurement data. Furthermore, a bracket 33 can be provided on the attitude change device 3 as in the third variation of embodiment 1.

[0102] Implementation Method 3

[0103] In Embodiments 1 and 2 described above, a system and method were described in which the posture of a workpiece taken from a scattered stacked state is changed using a posture changing device having a switching chuck and a rotating part, resulting in a posture different from the intended posture. In Embodiment 3, an example is described in which the posture changing device shown in Embodiments 1 and 2 is constructed using a posture changing robot to control the posture changing action of the workpiece.

[0104] Figure 19 and Figure 20 This is used to illustrate the structure and operation of the pickup system in Implementation Method 3. Figure 19 This is a schematic diagram used to illustrate the overall structure of the picking system. Figure 20This is a flowchart illustrating the operation of the pickup system. Furthermore, the parts of the equipment related to workpiece orientation changes, other than their structure and operation, are the same as those described in Embodiments 1 and 2; therefore, descriptions of the same parts are omitted, and the descriptions used in Embodiment 1 are referenced. Figure 1 , Figure 9 Other than the diagrams and those used in Implementation 2 Figure 17 , Figure 18 Other than the diagram.

[0105] In the picking system 1 of embodiment 3, such as Figure 19 As shown, a posture-changing robot 7 is provided instead of the posture-changing device 3 described in embodiments 1 and 2. Regarding the posture-changing robot 7, only one robot arm 71 is depicted. However, the posture-changing robot 7 is the same as the robot 2, consisting of a 5-DOF horizontal multi-joint robot, a 6-DOF vertical multi-joint robot, or a collaborative robot, and is equipped with multiple robot arms 71, multiple joints, a base, etc.

[0106] A flange 71f is provided at the far end of the robot arm 71 for mounting the robot hand 72 that holds the workpiece 90. The posture-changing robot 7 is connected to the robot control unit 23 of the robot 2. Moreover, the robot hand 72 of the posture-changing robot 7 controls the position and posture according to the instructions of the robot control unit 23 based on the information representing the posture of the workpiece 90 from the workpiece posture calculation unit 4.

[0107] Alternatively, the robot control unit of the posture-changing robot 7 can be configured as an independent robot control unit, which performs control differently from the robot 2. However, the independent robot control unit needs to be configured to be connected to the workpiece posture calculation unit 4.

[0108] The robot hand 72 is connected to the flange 71f of the robot arm 71 and is used as a tool to receive the workpiece 90 picked up by the robot hand 22 of the robot 2, change the orientation of the received workpiece 90, and then hand it back to the robot hand 22. The robot hand 72 holds the workpiece 90 handed over from the robot 2 according to the instructions of the robot control unit 23. At the end of the robot hand 72, a gripping claw 22c, as shown in Figures 2A and 2B, is detachably mounted, corresponding to the shape of the workpiece 90.

[0109] Furthermore, a second camera unit 42 is provided on the upper part of the posture-changing robot 7. This second camera unit 42 acquires camera data for calculating the posture of the workpiece 90 after the switching action is performed, and is configured to acquire data representing the posture and angle of the workpiece 90 held by the posture-changing robot 7. Therefore, after the switching action is performed, the workpiece 90 is returned to the robot 2. In addition to determining whether a switching action is necessary, the accuracy of the posture change of the workpiece 90 based on the switching action can be improved. The second camera unit 42 needs to be a device capable of acquiring a three-dimensional image of the workpiece 90, such as a three-dimensional vision sensor, or it can be a configuration with multiple camera units.

[0110] Based on the above structure, refer to Figure 20 The flowchart below explains the operation of the picking system 1 in Embodiment 3. Furthermore, the steps from capturing images of the workpieces 90 scattered on the workpiece placing device 6 (step S100) to holding the target workpiece (step S120) are the same as in Embodiment 1, and therefore the explanation is omitted.

[0111] Robot 2 moves the workpiece 90, which it has grasped and removed (step S120), to a position (reversal position) handed over to the posture-changing robot 7 (step S140). The reversal position is not uniquely determined; it is a position where the workpiece 90 does not interfere with surrounding objects and the reversal action is performed appropriately, based on the shape and posture of the workpiece 90 removed in step S120.

[0112] Then, the gripper of the robot hand 72 is opened, and as illustrated in FIG10B, the gripped workpiece 90 is transferred to the robot hand 72 of the posture changing robot 7 (step S250).

[0113] When workpiece 90 is handed over from robot 2 to attitude-changing robot 7, a three-dimensional image of workpiece 90 held by robot arm 72 attached to attitude-changing robot 7 is captured by second camera unit 42, and image processing is performed on the image by workpiece attitude calculation unit 4. Based on the image processing results of workpiece attitude calculation unit 4, position measurement data representing the attitude of workpiece 90 transferred to attitude-changing robot 7 is calculated (step S260).

[0114] Based on the information output from the workpiece posture calculation unit 4 or the robot control unit 23, using the posture data obtained in step S260, it is determined whether a posture change of the workpiece 90 is required based on the handover from the posture change robot 7 (step S600). If a posture change based on the posture change robot 7 is required (step S600: "Yes"), the robot arm 71 is moved by the control command of the robot control unit 23 to perform a posture change of the workpiece 90 together with the robot hand 72 (step S610). Then, the determination of whether a posture change of the workpiece 90 is required is performed again (step S600).

[0115] If no posture change is required, or if the posture change becomes unnecessary due to the posture change of the posture-based robot 7 described above (step S600: "No"), proceed to the next determination step (step S700). In step S700, a determination is made regarding whether the workpiece posture can be changed to a posture suitable for product placement (ideal posture), based on the imaging results of the second camera unit 42 and the control commands of the robot control unit 23.

[0116] If it is determined that the workpiece 90 is not in a position suitable for product placement (ideal position) (step S700: "No"), the workpiece 90 is transferred to another robot (robot 2 in the current described process) (step S710). Then, after determining whether a position change is needed in step S600, if a position change is needed, the position change action of the workpiece 90 is performed again.

[0117] Steps S600 to S710 are repeated to transfer the workpiece 90 between the robot 2 and the posture-changing robot 7, changing the workpiece 90 to the desired posture. The action after the posture change of the workpiece 90 is completed (step S700: "Yes") (step S510) is the same as in Embodiment 1, so the description is omitted.

[0118] As described above, in the picking system 1 of Embodiment 3, the workpiece 90 is exchanged multiple times between the robot 2 and the posture-changing robot 7, thereby enabling the workpiece switching operation to be performed with higher precision. Furthermore, by using the posture-changing robot 7 to perform the switching operation, the switching position of the workpiece 90 can be arbitrarily set within the range of motion.

[0119] In the attitude change device 3 of Embodiments 1 and 2, the switching chuck 31 is fixed. Therefore, when the shape or size of the workpiece 90 changes significantly, surrounding objects and the workpiece 90 may interfere, making it sometimes difficult to guide the workpiece 90 into a production site where there are many different types of workpieces. On the other hand, the pickup system 1 of Embodiment 3 can solve the above-mentioned problems when the shape or size of the workpiece 90 changes.

[0120] Furthermore, in the picking system 1 of Embodiment 3, both the robot 2 and the posture-changing robot 7 are capable of feeding workpieces into the product (step S510). That is, in Figure 20 In the flowchart, there is a case where the result is never determined as "yes" in step S600 or "no" in step S700. In this case, the workpiece can be put into the product using the posture change robot 7 (step S510).

[0121] On the other hand, in the pickup system 1 of Embodiments 1 and 2, the attitude change device 3 is fixed at one point within the pickup system 1, making it impossible to perform the workpiece placement operation for the product in step S510. Regarding this, in Embodiment 3, there is a possibility of reducing the number of workpiece changes, which can be said to have the effect of reducing the cycle time required for pickup.

[0122] In addition, Figure 20 The flowchart shows an example of transferring a workpiece 90, which can be held in a desired position, to the posture-changing robot 7, but it is not limited to this. For example, the angle and posture of the workpiece 90 can be determined before step S140, and if the angle and posture do not need to be changed, the process can directly proceed from step S120 to step S510.

[0123] Furthermore, this application describes exemplary embodiments; however, the various features, methods, and functions described in the embodiments are not limited to the application of specific embodiments and can be applied to embodiments individually or in various combinations. Therefore, numerous variations not illustrated can be conceived within the scope of the technology disclosed in this application. For example, these include cases involving modifications to at least one structural element, cases involving the addition of at least one structural element, or cases involving the omission of at least one structural element.

[0124] For example, in the control described above, the order of steps can be appropriately changed without altering the function and effect. Furthermore, the control mechanisms described above can be appropriately combined.

[0125] As described above, the picking system 1 according to this application is configured to include: a workpiece posture calculation unit 4, which has a camera unit 41 for capturing images of randomly stacked workpieces 90, calculating the posture of each workpiece 90 based on the image data obtained from the camera unit 41, selecting the workpiece 90 to be picked up, and determining the gripping position and angle; a robot 2, which grips and removes the selected workpiece 90 according to the determination of the workpiece posture calculation unit 4; and a posture changing device 3 (or posture changing robot 7), which has a chuck (reversing chuck 31 or robot arm 72) and a chuck (reversing chuck 31 or robot arm) for changing the chuck (reversing chuck 31 or robot arm) 72) The rotating part 32 (or robot arm 71) changes the posture of the part gripped by the chuck (changing chuck 31 or robot hand 72); and the control unit (e.g., robot control unit 23, workpiece posture calculation unit 4, rotating part 32 or microcomputer 800) changes the workpiece 90 held by the robot 2 to the posture changing device 3 (or posture changing robot 7) when the determined gripping position and angle deviate from the set gripping position and angle (as a pickup), so that the workpiece 90 is rotated and the robot 2 grips it again in a manner consistent with the set gripping position and angle. Therefore, the workpiece 90 supplied in an uneven posture state is changed to the desired angle for changing, so that the workpiece 90 can be reliably gripped in an appropriate posture and put into the product.

[0126] Especially when the rotation axis of the rotating part 32 is horizontal, the vertical direction of the workpiece 90 can be easily corrected.

[0127] Alternatively, if the tilt of the rotation axis of the rotating part 32 is variable, it can be easily corrected for any posture. Furthermore, since the workpiece 90 to be removed is a long object and the rotation axis is horizontal, even if the switching action cannot be performed due to interference with the ground 6f, the posture can be changed / corrected if the tilt of the rotation axis is variable.

[0128] The device has a second camera unit 42 that takes a picture of the workpiece held by the posture changing device 3. The workpiece posture calculation unit 4 recalculates the posture of the rotated workpiece 90 based on the picture data obtained from the second camera unit 42. If configured in this way, the posture of the workpiece 90 can be corrected more accurately.

[0129] The aforementioned posture changing device is a posture changing robot 7. The posture changing robot 7 has a robot hand 72 connected to the robot arm 71 and whose position and angle can be freely controlled as a chuck to accept the workpiece 90 taken out by the robot 2, thereby changing the posture of the accepted workpiece. If configured in this way, the posture of the workpiece 90 can be corrected more accurately. In addition, it can sometimes reduce the number of times the workpiece 90 is changed, and reduce the operation time required for the changing action.

[0130] Label Explanation

[0131] 1: Pick-up system; 2: Robot; 21: Robot arm; 22: Robot hand; 22c: Gripper; 23: Robot control unit (control unit); 3: Attitude change device; 31: Changing chuck; 31c: Gripper; 32: Rotating unit (control unit); 33: Carrier; 4: Workpiece attitude calculation unit (control unit); 41: Camera unit; 42: Second camera unit; 6: Workpiece loading device; 7: Attitude change robot (attitude change device); 71: Robot arm (rotating unit); 72: Robot hand (chuck); 90: Workpiece.

Claims

1. A pickup system, characterized in that, This pickup system has the following features: The workpiece posture calculation unit includes a camera unit that captures images of randomly piled workpieces, calculates the posture of each workpiece in the randomly piled workpieces based on the image data obtained from the camera unit, selects a pick-up target workpiece from the randomly piled workpieces, sets a first region, a second region and a third region for the workpiece, and determines the holding position and angle at the first region. The first region, the second region and the third region are different regions. A robot, based on the settings of the workpiece posture calculation unit, grasps the second region of the selected workpiece and removes the selected workpiece; An attitude change device having a chuck and a rotating part for rotating the chuck, for changing the attitude of a component held by the chuck; as well as The control unit causes the chuck to grip the third region of the workpiece held by the robot, thereby transferring the workpiece held by the robot to the posture changing device, and causing the workpiece gripped by the chuck to rotate so that the robot grips the first region in a manner consistent with the determined gripping position and angle.

2. The pickup system according to claim 1, characterized in that, The workpiece posture calculation unit is pre-inputted with three-dimensional model information related to the shape of the workpiece.

3. The pickup system according to claim 1, characterized in that, The axis of rotation of the rotating part is horizontal.

4. The pickup system according to claim 2, characterized in that, The axis of rotation of the rotating part is horizontal.

5. The pickup system according to claim 1, characterized in that, The tilt of the rotation axis of the rotating part is variable.

6. The pickup system according to claim 2, characterized in that, The tilt of the rotation axis of the rotating part is variable.

7. The pickup system according to any one of claims 1 to 6, characterized in that, The pickup system has a second camera unit that captures images of the workpiece gripped by the chuck. The workpiece posture calculation unit calculates the posture of the rotated workpiece again based on the camera data obtained from the second camera unit.

8. The pickup system according to any one of claims 1 to 6, characterized in that, The attitude change device is an attitude change robot, which has a robot hand connected to the robot arm and whose position and angle can be freely controlled as the chuck to accept the workpiece taken out by the robot and change the attitude of the accepted workpiece.

9. The pickup system according to claim 7, characterized in that, The attitude change device is an attitude change robot, which has a robot hand connected to the robot arm and whose position and angle can be freely controlled as the chuck to accept the workpiece taken out by the robot and change the attitude of the accepted workpiece.

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