Robot arm control system

Abstract

To arrange a workpiece with precision at a desired input position in a container without prolonging operation time.SOLUTION: A controller controls a robot arm 40 for performing work of inputting, in an aligned state, work-pieces 20 that are pillow packaging articles having seal cut parts 21, 22 into a rectangular container 50 with four sides 51-54 in plan view. The controller comprises a position setting part and an operation control part. If an input position is adjacent in a first direction B1 to an already arranged workpiece that is a workpiece 20 already arranged in the container 50, the operation control part brings an unarranged workpiece that is a workpiece 20 to be arranged hereafter, into contact with the already arranged workpiece, in order to arrange the unarranged workpiece at the input position after setting the seal cut parts 21, 22 of the unarranged workpiece and the seal cut parts 21, 22 of the already arranged workpiece into a folded state toward a bottom part side of the container 50.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a control system for a robotic arm.

Background Art

[0002] Conventionally, as disclosed in Patent Document 1, there is a production system in which a plurality of workpieces are circulated on a production line in a factory by being conveyed by a conveying device such as a conveyor, and a robotic arm performs predetermined operations on these circulated workpieces. As one of the operations by such a robotic arm, there is a pick-and-place operation of picking up a workpiece that is a pillow-packaged product having a seal-cut portion and placing it at a predetermined insertion position in a container having a rectangular shape in plan view. Note that the pillow-packaged product having a seal-cut portion is, for example, a snack such as individually packaged butter cookies, and the container having a rectangular shape in plan view is, for example, a cardboard box. In such a case, it is required to pack the workpieces in the container in a state where there are no gaps and they are aligned as much as possible.

[0003] In this case, it is common for the robotic arm to perform the following operations when placing the workpiece in the container. That is, the robotic arm moves the arm while gripping the workpiece with a hand attached to the tip of the arm, positions the tip of the arm above the insertion position in the container, then lowers the tip of the arm straight down, releases the workpiece from the hand, and places the workpiece at the insertion position in the container. Also, in this case, the following is a common order for inserting the workpieces into the container. That is, the robotic arm first inserts the workpieces into a row at one end, which is one end of the container, then inserts the workpieces into a middle row, which is a row between both ends of the container, and then inserts the workpieces into a row at the other end, which is the other end of the container, in this order.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] In conventional pick-and-place operations that employ the general placing actions and workpiece loading sequences described above, when a workpiece is released from the robot arm to be loaded into a middle or other end row, there is a high possibility of interference between that workpiece and an adjacent workpiece already placed there, specifically, a high possibility of contact between the seal cut portions of those workpieces. In the following, such conventional pick-and-place operations may be referred to as prior art.

[0006] When such interference occurs between workpieces, specifically when the seal cut portions of the workpieces come into contact with each other, the following problems may arise. That is, if the contacted seal cut portions are bent, the resulting repulsive force, specifically the repulsive force caused by the seal cut portions trying to return to their original shape, may cause the workpieces placed in the container to deviate from their desired placement. Generally, confectionery is lighter than bread, frozen foods, etc. Therefore, when packing such relatively light workpieces into a container in an aligned manner without gaps, the aforementioned problem of misalignment becomes even more pronounced.

[0007] If such misalignment occurs, there is a risk of damaging the workpiece when another workpiece is placed into the container, such as by being crushed from above. Also, containers such as food boxes are sometimes stacked in multiple layers, and if another container is stacked on top of a container containing a misaligned workpiece, the misalignment may cause the workpiece to protrude from the top surface of the container. Therefore, if the container is relatively heavy, there is a risk of damaging the workpiece, and if the container is relatively light, there is a risk of not being able to stack the containers properly.

[0008] In conventional technology, to prevent such misalignment, one possible measure is to position the workpieces close to the inner wall on one end of the container when placing them in the first row, thereby minimizing interference with the workpieces in the next row to be placed. However, this measure requires movement to bring the workpieces close to the inner wall of the container during placement, which may lead to the following additional problems. Specifically, the above measure involves unnecessary movement in the pick-and-place operation, such as bringing the workpieces close to the inner wall, which may lead to a longer working time. Furthermore, the above measure may cause the workpieces to come into contact with the inner wall and be damaged due to being positioned too close.

[0009] This invention has been made in view of the above circumstances, and its purpose is to provide a robot arm control system that can accurately position a workpiece at a desired input position within a container without increasing the working time. [Means for solving the problem]

[0010] The robot arm control system described in claim 1 controls a robot arm that performs the task of loading workpieces, which are pillow-packaged products having seal-cut portions at least at both ends, into a rectangular container having four sides in a plan view, in an aligned state, and comprises a position setting unit and an motion control unit. In this case, if the direction along the first and second sides, which are two sides of the four sides that are opposite to each other, is defined as the first direction, and the direction along the third and fourth sides, which are two sides of the four sides excluding the first and second sides, is defined as the second direction, then the aligned state includes a state in which a plurality of workpieces are lined up along the first direction such that the sides on which the seal-cut portions are provided are adjacent to each other.

[0011] The position setting unit sets the loading position of the workpiece in the container. The motion control unit picks up the workpiece at a predetermined acquisition position and controls the movement of the robot arm to place the picked-up workpiece at the loading position set by the position setting unit. If the loading position is adjacent in the first direction to a previously placed workpiece that is already placed in the container, the motion control unit brings the unplaced workpiece to be placed into contact with the previously placed workpiece, causing the seal cut portion of the unplaced workpiece and the seal cut portion of the previously placed workpiece to fold toward the bottom of the container, and then places the unplaced workpiece at the loading position.

[0012] In this way, when an unplaced workpiece is placed at an adjacent input position in the first direction of an already placed workpiece, the seal cut portions of those workpieces are folded toward the bottom, thus suppressing interference between the unplaced and already placed workpieces and positional displacement when the unplaced workpiece leaves the robot arm. Thus, with the above configuration, positional displacement is suppressed, preventing problems such as damage to the workpieces or inability to properly stack containers.

[0013] With the above configuration, when placing a workpiece at an input position adjacent to one of the third or fourth sides, i.e., at the input position in the end row of the container, extra movements such as bringing the workpiece close enough to the inner wall on the end side of the container are eliminated, thus preventing misalignment as described above. Therefore, with the above configuration, the excellent effect of being able to accurately place the workpiece at the desired input position in the container without increasing the working time is obtained.

[0014] In the robot arm control system according to claim 2, if the input position is adjacent to the already placed workpiece in the first direction, the motion control unit brings the seal cut portion of the unplaced workpiece into contact with the seal cut portion of the already placed workpiece, thereby folding the seal cut portion of the unplaced workpiece and the seal cut portion of the already placed workpiece toward the bottom of the container, and then places the unplaced workpiece at the input position.

[0015] In the above configuration, in order to fold the seal cut portions of the unplaced workpieces and the already placed workpieces toward the bottom of the container, methods such as bringing the main body portions of each workpiece (excluding the seal cut portions) into contact with each other, or bringing the seal cut portion of one workpiece into contact with the main body portion of the other workpiece, can be considered. However, such methods may lead to the following problems.

[0016] In other words, if the workpiece is, for example, a pillow-packaged confectionery such as Baumkuchen, the contents are softer than the seal-cut portion. Therefore, when working with such a workpiece, methods that involve bringing the main bodies of each workpiece into contact with each other, or bringing the seal-cut portion of one workpiece into contact with the main body of another workpiece, may damage the relatively soft contents of the workpiece. In contrast, as described above, by bringing the seal-cut portions of the workpieces into contact with each other, the seal-cut portions can be folded without damaging the relatively soft contents of the workpiece. [Brief explanation of the drawing]

[0017] [Figure 1] A schematic diagram showing the configuration of the production system according to the first embodiment. [Figure 2] A schematic diagram showing the configuration of the controller according to the first embodiment. [Figure 3] Figure 1 illustrates an example of a specific operation related to the pick-and-place operation according to the first embodiment. [Figure 4]Figure 2 for explaining an example of a specific operation related to the pick-and-place operation according to the first embodiment [Figure 5] Figure 3 for explaining an example of a specific operation related to the pick-and-place operation according to the first embodiment [Figure 6] Figure 4 for explaining an example of a specific operation related to the pick-and-place operation according to the first embodiment [Figure 7] Figure 5 for explaining an example of a specific operation related to the pick-and-place operation according to the first embodiment [Figure 8] Diagram schematically showing a state in which a plurality of workpieces are gripped by respective gripping portions of the hand according to the first embodiment [Figure 9] Figure 6 for explaining an example of a specific operation related to the pick-and-place operation according to the first embodiment [Figure 10] Diagram showing an example of a place operation when the input positions of three workpieces arranged along the first direction according to the first embodiment are set by the first setting method [Figure 11] Diagram showing an example of a place operation when the input positions of three workpieces arranged along the first direction according to the first embodiment are set by the second setting method [Figure 12] Figure 1 for explaining the first specific example of the diagonal approach operation according to the first embodiment [Figure 13] Figure 2 for explaining the first specific example of the diagonal approach operation according to the first embodiment [Figure 14] Figure 3 for explaining the first specific example of the diagonal approach operation according to the first embodiment [Figure 15] Figure 1 for explaining the second specific example of the diagonal approach operation according to the first embodiment [Figure 16] Figure 2 for explaining the second specific example of the diagonal approach operation according to the first embodiment [Figure 17] Figure 3 for explaining the second specific example of the diagonal approach operation according to the first embodiment [Figure 18]This figure shows an example of a placing operation using a normal approach when the input positions of three workpieces arranged along the first direction in the first comparative example are set by the second setting method. [Figure 19] This diagram schematically shows the state in which multiple workpieces are gripped by each of the gripping parts of the hand according to the second comparative example. [Figure 20] A diagram illustrating an example of specific operations related to the pick-and-place operation when loading a workpiece into the second container according to the second embodiment. [Figure 21] Figure 1 illustrates an example of specific operations related to the pick-and-place operation when placing a workpiece into the first container according to the second embodiment. [Figure 22] Figure 2 illustrates an example of specific operations related to the pick-and-place operation when placing a workpiece into the first container according to the second embodiment. [Figure 23] Figure 3 illustrates an example of specific operations related to the pick-and-place operation when placing a workpiece into the first container according to the second embodiment. [Figure 24] Figure 4 illustrates an example of specific operations related to the pick-and-place operation when placing a workpiece into the first container according to the second embodiment. [Figure 25] Figure 5 illustrates an example of specific operations related to the pick-and-place operation when placing a workpiece into the first container according to the second embodiment. [Figure 26] Figure 6 illustrates an example of specific operations related to the pick-and-place operation when placing a workpiece into the first container according to the second embodiment. [Modes for carrying out the invention]

[0018] Several embodiments will be described below with reference to the drawings. In each embodiment, substantially identical components are denoted by the same reference numerals and their descriptions are omitted. (First Embodiment) The first embodiment will be described below with reference to Figures 1 to 19.

[0019] As shown in Figures 1 and 3, in the production system 10 of this embodiment, workpieces 20 are transported by a conveyor 30, which is a belt conveyor device, to be distributed to the production line within the factory. The production system 10 includes a process as shown in Figures 1 and 3, in which, when workpieces 20 are transported by the conveyor 30, the robot arm 40 takes the workpieces 20 and places them into the container 50 in an aligned state, that is, a transfer process from the conveyor 30 to the container 50.

[0020] In other words, the robot arm 40 picks up the workpieces 20 being transported by the conveyor 30 in a predetermined flow direction A1, and performs a pick-and-place operation by placing the picked-up workpieces 20 into the container 50 in an aligned state. The conveyor 30 is equivalent to a transport device and is basically designed to operate continuously without stopping. The workpieces 20 are pillow-packaged products with seal-cut sections 21 and 22, and their contents are, for example, sweets such as Baumkuchen. The seal-cut sections 21 and 22 are provided on two of the four sides of the workpiece 20 that are opposite each other. Note that in Figures 1, 3, etc., only some of the seal-cut sections are labeled with reference numerals, and the reference numerals for the other seal-cut sections are omitted.

[0021] In this case, the workpiece 20 is pillow-packaged in a preceding process and transported to the main process in an individually packaged state. In this case, the workpiece 20 is transported continuously by the conveyor 30 at a constant speed and at constant intervals, and is transported in a direction such that the sides provided with the seal-cut sections 21 and 22 are perpendicular to the flow direction A1.

[0022] The robot arm 40 is configured as a vertical articulated robot having, for example, a 6-axis arm. The container 50 is a rectangular container, such as a food container, having four sides 51, 52, 53, and 54 in a plan view. In this specification, two sides 51 and 52 that are opposite each other are also referred to as the first side 51 and the second side 52, respectively, and two sides 53 and 54 that are not the first side 51 and the second side 52 are also referred to as the third side 53 and the fourth side 54, respectively.

[0023] Furthermore, in this specification, the direction along the first side 51 and the second side 52 is referred to as the first direction B1, and the direction along the third side 53 and the fourth side 54 is referred to as the second direction B2. In addition, in this specification, the first direction B1 may be referred to as a row, and the second direction B2 may be referred to as a column. In this case, the aforementioned alignment state is the state shown in Figures 10 and 11, that is, multiple workpieces 20, specifically three workpieces 20, are arranged along the first direction B1 with their sides having seal-cut portions 21 and 22 adjacent to each other, and multiple workpieces 20, specifically five workpieces 20, are arranged along the second direction B2 with their sides not having seal-cut portions 21 and 22 adjacent to each other.

[0024] In other words, in this embodiment, 15 workpieces 20 are arranged in the container 50 in an aligned state in a 5x3 configuration. In this specification, the five rows will be referred to as the 1st row, 2nd row, 3rd row, 4th row, and 5th row, respectively, from top to bottom in Figures 10, 11, etc., and the three columns will be referred to as the 1st column, 2nd column, and 3rd column, respectively, from left to right in Figures 10, 11, etc.

[0025] The robot arm 40 and the container 50 are positioned on workbenches 60 and 70, respectively. In this case, workbenches 60 and 70, and consequently the robot arm 40 and the container 50, are positioned on the right side with respect to the flow direction A1. In this specification, the right side with respect to the flow direction A1 may be simply referred to as the right side, and the left side with respect to the flow direction A1 may be simply referred to as the left side.

[0026] A hand 80 is attached to the tip of the robot arm 40. As shown in Figures 1 and 3, the hand 80 has multiple gripping parts, specifically five gripping parts 81, 82, 83, 84, and 85, which are arranged in a predetermined alignment direction C1 and capable of gripping a workpiece 20. The gripping parts 81 to 85 are equipped with a suction mechanism for adsorbing and holding the workpiece 20. Thus, in this embodiment, the number of gripping parts 81 to 85 on the hand 80 is "5", which is the same number as the number of workpieces 20 that are aligned along the second direction B2 in the aligned state.

[0027] The robot arm 40 moves its tip to position itself near the conveyor 30, then moves its tip further and performs a picking operation, sequentially picking up the workpiece 20 with each of the multiple gripping parts 81-85 of the hand 80. Then, the robot arm 40 moves its tip to position itself near the container 50, then moves its tip further and performs a placing operation, releasing the workpiece 20 from the gripping parts 81-85 and placing it in a predetermined position in the container 50. The robot arm 40 repeatedly performs this series of operations on the workpiece 20, that is, picking up the workpiece 20 being transported by the conveyor 30 and placing it into the container 50.

[0028] The robot arm 40 is controlled by the controller 90 shown in Figure 2. The controller 90 constitutes the control system for the robot arm and controls the robot arm 40 by executing a computer program in a control means consisting of a computer (not shown) composed of a CPU, ROM, RAM, etc. Specifically, the controller 90 is equipped with a drive unit consisting of an inverter circuit, etc., and drives each motor based on the rotational position of the motor detected by an encoder provided corresponding to the motor that drives each axis of the robot arm 40, for example by feedback control. The controller 90 controls the robot arm 40 so that each axis of the robot arm 40 automatically performs a predetermined operation by executing a preset operation program.

[0029] The controller 90 includes functional blocks such as a position setting unit 91 and an operation control unit 92. Each of these functional blocks is implemented by the CPU of the controller 90 executing a computer program stored in ROM or the like to perform processing corresponding to the computer program; in other words, it is implemented by software. However, it is also possible to configure the controller 90 so that at least a portion of each functional block is implemented by hardware.

[0030] The position setting unit 91 sets the loading position of the workpiece 20 in the container 50. The position setting unit 91 sets the loading position to the position specified by the user during teaching, i.e., by the coordinate setting. When setting the loading positions of three workpieces 20 arranged along the first direction B1, the position setting unit 91 can use one of the following two setting methods. In the first setting method, the position setting unit 91 first sets a position adjacent to one of the third side 53 and the fourth side 54 as the loading position, then sets a position adjacent to the other of the third side 53 and the fourth side 54 as the loading position, and then sets a position that is not adjacent to either the third side 53 or the fourth side 54 as the loading position.

[0031] In other words, in the first setting method, the position setting unit 91 first sets the position of the first column, which is the column on one end of the container 50, as the input position, then sets the position of the third column, which is the column on the other end of the container 50, as the input position, and then sets the position of the second column, which is the column between both ends of the container 50, as the input position.

[0032] In the second setting method, the position setting unit 91 first sets a position adjacent to one of the third side 53 and the fourth side 54 as the input position, then sets a position not adjacent to either the third side 53 or the fourth side 54 as the input position, and then sets a position adjacent to the other of the third side 53 or the fourth side 54 as the input position. In other words, in the second setting method, the position setting unit 91 first sets the position of the first column as the input position, then sets the position of the second column as the input position, and then sets the position of the third column as the input position.

[0033] The motion control unit 92 controls the movement of the robot arm 40 to pick up the workpiece 20 at a predetermined acquisition position on the conveyor 30 and to position the picked-up workpiece 20 at the input position set by the position setting unit 91. In this case, the conveyor 30 extends in the left-right direction in Figure 2, and the workpiece 20 is transported from right to left in Figure 2. In other words, in this case, the transport direction of the workpiece 20 is the flow direction A1 shown by the white arrow in Figure 2.

[0034] If the input position is adjacent in the first direction B1 to a workpiece 20 already placed in the container 50, the operation control unit 92 can place the unplaced workpiece 20 to be placed in the input position after bringing the unplaced workpiece 20 to be placed in contact with the already placed workpiece, causing the seal cut portions 21 and 22 of the unplaced workpiece and the seal cut portions 21 and 22 of the already placed workpiece to be folded toward the bottom of the container 50.

[0035] The motion control unit 92 can move the hand 80 from right to left along the alignment direction C1, with the hand 80 oriented so that the flow direction A1 and the alignment direction C1 are perpendicular to each other, and sequentially pick up the workpieces 20 with each of the multiple gripping parts 81 to 85, and then collectively place all the picked-up workpieces 20 at the input position. Furthermore, after the workpieces 20 are placed at the input position, the motion control unit 92 can control the movement of the robot arm 40 so that it returns to an initial position where one of the multiple gripping parts 81 to 85 is positioned above the acquisition position.

[0036] Next, we will describe a specific example of the operation of the pick-and-place operation performed by the robot arm 40 with the above configuration. Note that in Figures 3 to 7, Figure 9, etc., the robot arm 40 is not shown, and only the hand 80 attached to the end of the arm is shown.

[0037] [1] Picking action As shown in Figures 3 to 7, the picking operation involves moving the hand 80 from right to left along the alignment direction C1, with the hand 80 oriented so that the flow direction A1 and the alignment direction C1 are perpendicular to each other, and sequentially picking up the workpiece 20 with each of the gripping parts 81 to 85. First, as shown in Figure 3, the motion control unit 92 controls the movement of the robot arm 40 so that the initial position is such that the gripping part 81 is positioned above the acquisition position.

[0038] The motion control unit 92 then grips the workpiece 20 with the gripping unit 81 when the workpiece 20 reaches the acquisition position, that is, the position directly below the gripping unit 81. The motion control unit 92 is able to know the timing when the workpiece 20 reaches the acquisition position using various sensors attached to the conveyor 30, and grips the workpiece 20 based on that timing.

[0039] Next, as shown in Figure 4, the motion control unit 92 controls the movement of the robot arm 40 so that the gripping unit 82 is positioned above the acquisition position. Then, the motion control unit 92 grips the workpiece 20 with the gripping unit 82 when the workpiece 20 reaches a position directly below the gripping unit 82. Next, as shown in Figure 5, the motion control unit 92 controls the movement of the robot arm 40 so that the gripping unit 83 is positioned above the acquisition position. Then, the motion control unit 92 grips the workpiece 20 with the gripping unit 83 when the workpiece 20 reaches a position directly below the gripping unit 83.

[0040] Next, as shown in Figure 6, the motion control unit 92 controls the movement of the robot arm 40 so that the gripping unit 84 is positioned above the acquisition position. Then, when the workpiece 20 reaches a position directly below the gripping unit 84, the motion control unit 92 grips the workpiece 20 with the gripping unit 84. Next, as shown in Figure 7, the motion control unit 92 controls the movement of the robot arm 40 so that the gripping unit 85 is positioned above the acquisition position. Then, when the workpiece 20 reaches a position directly below the gripping unit 85, the motion control unit 92 grips the workpiece 20 with the gripping unit 85.

[0041] As a result of this picking operation, five workpieces 20 are gripped by the gripping portions 81-85 of the hand 80. In this case, the workpieces 20 are transported in a direction such that the sides with the seal-cut portions 21 and 22 are perpendicular to the flow direction A1, and the hand 80 is positioned so that the flow direction A1 and the alignment direction C1 are perpendicular to each other when it takes hold of the workpieces 20. As shown in Figure 8, the five workpieces 20 gripped by the hand 80 are naturally arranged so that the sides without the seal-cut portions 21 and 22 are adjacent to each other.

[0042] In this case, since the container 50 is positioned so that its second direction B2 aligns with the flow direction A1 of the conveyor 30, the orientation of the hand 80 needs to be rotated 90 degrees from the orientation during the picking operation when performing a placing operation. Therefore, after the gripping units 81 to 85 each grip the five workpieces 20, the motion control unit 92 rotates the orientation of the hand 80 90 degrees from the orientation during the picking operation either before moving the arm tip toward the container 50, after moving the arm tip toward the container 50, or while moving the arm tip toward the container 50. As a result, as shown in Figure 9, the alignment direction C1 of the hand 80 aligns with the second direction B2 of the container 50.

[0043] [2] Place action When the input positions of three workpieces 20 arranged along the first direction B1 are set by the first setting method, the placing operation is as shown in Figure 10, for example. In Figure 10 and other figures, only some workpieces are labeled with reference numerals, while the reference numerals for other workpieces are omitted. That is, as shown in Figure 10(a), the motion control unit 92 controls the operation of the robot arm 40 so that the five workpieces 20 gripped by the gripping units 81 to 85 are placed collectively at each input position in the first row. At this time, the motion control unit 92 positions each of the five workpieces 20 directly above their respective input positions, then lowers the tip of the arm straight down, and then controls the operation of the robot arm 40 so that the workpieces 20 are released from the gripping units 81 to 85 and placed at each input position in the first row. In this specification, the operation of placing the workpieces 20 as described above is referred to as the normal approach operation.

[0044] Next, as shown in Figure 10(b), the motion control unit 92 controls the movement of the robot arm 40 so that the five workpieces 20 gripped by the gripping units 81 to 85 are placed collectively at each input position in the third row. At this time, the motion control unit 92 controls the movement of the robot arm 40 so that the workpieces 20 are placed at each input position in the third row by a normal approach motion, similar to when placing the workpieces 20 at each input position in the first row.

[0045] Finally, as shown in Figure 10(c), the motion control unit 92 controls the movement of the robot arm 40 so that the five workpieces 20 gripped by the gripping units 81 to 85 are placed collectively at each input position in the second row. In this case, the motion control unit 92 controls the movement of the robot arm 40 so that the workpieces 20 are placed at each input position in the second row by a normal approach motion, similar to when placing the workpieces 20 at each input position in the first and third rows.

[0046] Furthermore, when the input positions of the three workpieces 20 arranged along the first direction B1 are set by the second setting method, the placing operation will be as shown in Figure 11, for example. That is, as shown in Figure 11(a), the motion control unit 92 controls the operation of the robot arm 40 so that the five workpieces 20 gripped by the gripping units 81 to 85 are placed collectively at each input position in the first row. In this case, the motion control unit 92 controls the operation of the robot arm 40 so that the workpieces 20 are placed at each input position in the first row by the normal approach operation described above.

[0047] Next, as shown in Figure 11(b), the motion control unit 92 controls the movement of the robot arm 40 to collectively position the five workpieces 20, each gripped by the gripping units 81-85, at each input position in the second row. At this time, the motion control unit 92 positions each of the five workpieces 20 above their respective input positions, then lowers the workpieces 20 at an angle, and then controls the movement of the robot arm 40 to release the workpieces 20 from the gripping units 81-85 and position them at each input position in the second row. In this specification, the operation of positioning the workpieces 20 as described above is referred to as the oblique approach operation.

[0048] Finally, as shown in Figure 11(c), the motion control unit 92 controls the movement of the robot arm 40 so that the five workpieces 20 gripped by the gripping units 81 to 85 are placed collectively at each input position in the third row. In this case, the motion control unit 92 controls the movement of the robot arm 40 so that the workpieces 20 are placed at each input position in the third row by an oblique approach, similar to when the workpieces 20 are placed at each input position in the second row.

[0049] The diagonal approach operation described above can be performed in the form of, for example, the first and second specific examples described below. Here, the unplaced workpiece to be placed at the input position is referred to as workpiece 20A, and the already placed workpiece adjacent to it in the first direction B1 of the input position is referred to as workpiece 20B. The first specific example of the diagonal approach operation is shown in Figures 12 to 14.

[0050] In this case, as shown in Figure 12, the motion control unit 92 tilts the workpiece 20A diagonally so that the seal cut portion 21 of the workpiece 20A, which is gripped by the gripping portion 81, hangs downward in the direction shown in Figure 12, that is, vertically downward, in other words, downward in a direction perpendicular to the installation surface of the workpiece 20, that is, the bottom surface of the container 50. Subsequently, the motion control unit 92 moves the tip of the arm so that the workpiece 20A descends diagonally toward the workpiece 20B. As a result, as shown in Figure 13, the seal cut portion 21 of the workpiece 20A and the seal cut portion 22 of the workpiece 20B come into contact.

[0051] Subsequently, the motion control unit 92 moves the tip of the arm to return the tilt of the workpiece 20A to its original position, that is, so that the bottom surface of the workpiece 20A, as shown in Figure 14, is aligned with the bottom of the container 50. As a result, the seal cut portion 21 of workpiece 20A and the seal cut portion 22 of workpiece 20B are folded toward the bottom of the container 50, and workpiece 20A is then placed in the loading position. Through this first operation, the motion control unit 92 brings the seal cut portion 21 of workpiece 20A, which is an unplaced workpiece, into contact with the seal cut portion 22 of workpiece 20B, which is an already placed workpiece, thereby folding the seal cut portion 21 of workpiece 20A and the seal cut portion 22 of workpiece 20B toward the bottom of the container 50.

[0052] A second specific example of the oblique approach operation is shown in Figures 15 to 17. In this case, as shown in Figure 15, the motion control unit 92 tilts the workpiece 20A, which is gripped by the gripping unit 81, by 90 degrees, that is, it tilts the workpiece 20 so that the side of the workpiece 20A with the seal-cutting unit 21 is on the lower side in Figure 15 and so on. Subsequently, the motion control unit 92 moves the tip of the arm so that the workpiece 20A descends toward the workpiece 20B. As a result, as shown in Figure 16, the main body portion of the workpiece 20A and the main body portion of the workpiece 20B come into contact.

[0053] Subsequently, the motion control unit 92 moves the tip of the arm to return the tilt of the workpiece 20A to its original position, that is, so that the bottom surface of the workpiece 20A, which is the lower surface as shown in Figure 14, etc., is aligned with the bottom of the container 50. As a result, the seal cut portion 21 of workpiece 20A and the seal cut portion 22 of workpiece 20B are folded toward the bottom of the container 50, and then workpiece 20A is placed in the input position. Through this second operation, the motion control unit 92 brings the main body portion of workpiece 20A, which is an unplaced workpiece, into contact with the main body portion of workpiece 20B, which is an already placed workpiece, thereby folding the seal cut portion 21 of workpiece 20A and the seal cut portion 22 of workpiece 20B toward the bottom of the container 50.

[0054] According to the embodiment described above, the following effects can be obtained. The position setting unit 91 can perform either the first setting method or the second setting method when setting the input positions of three workpieces 20 arranged along the first direction B1. In the first setting method, the position setting unit 91 first sets the position of the first column, which is the column on one end of the container 50, as the input position, then sets the position of the third column, which is the column on the other end of the container 50, as the input position, and then sets the position of the second column, which is the column between the two ends of the container 50, as the input position.

[0055] In a placing operation where the input positions of three workpieces 20 arranged along the first direction B1 are set by the first setting method, the robot arm 40 will input the workpieces 20 into the container 50 in the following order: first, the workpieces 20 into the first row of the container 50; then, the workpieces 20 into the third row of the container 50; and finally, the workpieces 20 into the second row, which is the row between the ends of the container 50.

[0056] With this loading order, when placing workpieces 20 in the loading positions in the first and third columns, which are the columns at both ends of the container 50, there are no already placed workpieces 20 adjacent to that loading position. Therefore, no positional misalignment due to interference between the unplaced workpieces 20 to be placed and the already placed workpieces will occur. However, with this loading order, when placing workpieces 20 in the second column, which is the column between the ends of the container 50, there will be already placed workpieces on both sides of that loading position.

[0057] Therefore, due to the repulsive force caused by interference between unplaced and already placed workpieces, the position of the unplaced workpiece may be shifted away from the desired input position. However, in this case, the movement of the workpiece 20 placed in the second column along the first direction B1 is restricted by the already placed workpieces in the adjacent first and third columns. Thus, in this case, even when placing the workpiece 20 in the input position of the second column, which is the column between the ends of the container 50, it is possible to prevent positional displacement due to interference between unplaced and already placed workpieces.

[0058] In a placing operation where the input positions of three workpieces 20 arranged along the first direction B1 are set by the second setting method, the robot arm 40 will input the workpieces 20 into the container 50 in the following order: first, the workpieces 20 into the first row of the container 50; then, the workpieces 20 into the second row of the container 50; and finally, the workpieces 20 into the third row of the container 50.

[0059] With this loading order, when placing the workpieces 20 at the loading positions in the second and third columns of the container 50, there will be already placed workpieces next to those loading positions. Therefore, when using a normal approach motion to place the workpieces 20 at the loading positions in the second and third columns, as shown in Figure 18 as the first comparative example, a positional shift may occur where the unplaced workpieces are moved away from the desired loading position due to the repulsive force caused by interference between the unplaced and already placed workpieces.

[0060] Therefore, in this embodiment, when the input positions of the three workpieces 20 arranged along the first direction B1 are set by the second setting method, in the placing operation, when placing the workpieces 20 at the input positions in the second and third rows of the container 50, the operation control unit 92 brings the unplaced workpieces into contact with the already placed workpieces, causing the seal cut portions 21 and 22 of the unplaced workpieces and the seal cut portions 21 and 22 of the already placed workpieces to fold toward the bottom of the container 50, and then places the unplaced workpieces at the input positions.

[0061] In this way, when an unplaced workpiece is placed at an adjacent input position in the first direction B1 of an already placed workpiece, the seal cut portions 21 and 22 of those workpieces 20 are folded toward the bottom, thus suppressing interference between the unplaced workpiece and the already placed workpiece and positional displacement when the unplaced workpiece moves away from the hand 80 attached to the tip of the robot arm 40.

[0062] The motion control unit 92 can adopt the operation of the first example as a specific operation for the oblique approach operation. According to the operation of the first example, by bringing the seal cut portions 21 and 22 of the unplaced workpiece into contact with the seal cut portions 21 and 22 of the already placed workpiece, the seal cut portions 21 and 22 of the unplaced workpiece and the seal cut portions 21 and 22 of the already placed workpiece can be folded toward the bottom side of the container 50.

[0063] In the above configuration, in order to fold the seal cut portions 21 and 22 of the unplaced workpieces and the seal cut portions 21 and 22 of the already placed workpieces toward the bottom of the container 50, it is conceivable to adopt a method of bringing the main body portions of each workpiece 20, excluding the seal cut portions 21 and 22, into contact with each other, that is, the operation of the second specific example, or to adopt a method of bringing the seal cut portions 21 and 22 of one workpiece 20 into contact with the main body portion of the other workpiece 20. However, these methods may lead to the following problems.

[0064] In other words, as in this embodiment, when the workpiece 20 is a pillow-packaged confectionery such as Baumkuchen, the contents are softer than the seal-cut portions 21 and 22. Therefore, when such workpieces 20 are used for pick-and-place operations, methods that involve bringing the main body portions of each workpiece 20 into contact with each other, or bringing the seal-cut portions 21 and 22 of one workpiece 20 into contact with the main body portion of the other workpiece 20, may damage the relatively soft contents of the workpieces 20.

[0065] In contrast, as in this embodiment, by bringing the seal-cut portions 21 and 22 of the workpiece 20 into contact with each other, the seal-cut portions 21 and 22 can be folded without damaging the relatively soft contents of the workpiece 20. If the contents of the workpiece 20 are not particularly softer than the seal-cut portions 21 and 22, the operation of the second specific example can be adopted as the specific operation of the oblique approach.

[0066] Thus, according to this embodiment, the occurrence of misalignment is suppressed, thereby preventing problems such as damage to the workpiece 20 or inability to properly stack the containers 50. Furthermore, according to this embodiment, when placing the workpiece 20 at an input position adjacent to one of the third side 53 and the fourth side 54, that is, at the input position in the first or third row, which are the end rows of the container 50, it is possible to prevent misalignment without requiring extra actions such as bringing the workpiece 20 close to the inner wall on the end side of the container 50. Therefore, according to this embodiment, the excellent effect of being able to accurately place the workpiece 20 at the desired input position in the container 50 without increasing the working time is obtained.

[0067] In this embodiment, the workpiece 20 is transported in such a orientation that the side portions provided with seal-cut portions 21 and 22 are perpendicular to the flow direction A1 of the conveyor 30. In this case, the robot arm 40 is equipped with a hand 80 in which a plurality of gripping portions 81 to 85 capable of gripping the workpiece 20 are arranged in a predetermined alignment direction C1. In the above configuration, the motion control unit 92 may also perform the control contents of the second comparative example described below, instead of the control contents described in this embodiment.

[0068] In other words, in the second comparative example, the motion control unit 92 moves the hand 80 with the orientation of the hand 80 such that the alignment direction C1 is aligned with the flow direction A1, and sequentially picks up the workpieces 20 with each of the multiple gripping parts 81 to 85, and controls the operation of the robot arm 40 so that all the picked-up workpieces 20 are placed together at the input position. According to this second comparative example, as shown in Figure 19, the multiple workpieces 20 gripped by the gripping parts 81 to 85 are arranged so that the sides with seal-cutting parts 21 and 22 are adjacent to each other.

[0069] Therefore, according to the second comparative example, there is a risk that the seal-cutting portions 21 and 22 of the multiple workpieces 20 gripped by the gripping portions 81 to 85 of the hand 80 may come into contact with each other and shift in position, which may result in being unable to pick accurately. In the above configuration, if the picking accuracy decreases, the placing accuracy may also decrease, potentially causing positional shifts.

[0070] In contrast, in this embodiment, the motion control unit 92 controls the movement of the robot arm 40 so that the hand 80 is oriented such that the flow direction A1 and the alignment direction C1 are perpendicular to each other, and moves the hand 80 along the alignment direction C1, and sequentially picks up the workpieces 20 with each of the multiple gripping parts 81 to 85, and then places all the picked-up workpieces 20 at once at the input position. In this way, when multiple workpieces 20 are gripped by the gripping parts 81 to 85 of the hand 80, the gripped workpieces 20 are naturally arranged so that the sides without seal-cutting parts 21 and 22 are adjacent to each other.

[0071] Therefore, with the above configuration, the seal-cutting portions 21 and 22 of the multiple workpieces 20 gripped by the gripping portions 81 to 85 of the hand 80 will not come into contact with each other and shift in position. As a result, accurate picking can be performed, and consequently, the occurrence of positional shifts during placing can be suppressed. In this way, with the above configuration, the occurrence of positional shifts is suppressed, which prevents problems such as damaging the workpieces 20 or being unable to properly stack the containers 50.

[0072] With the above configuration, since the occurrence of misalignment is prevented as described above, there is no need to use a hand with an adjustment mechanism that has a mechanism for adjusting the pitch as the hand 80. Therefore, with the above configuration, problems that may occur when using a hand with an adjustment mechanism, namely, the complexity of the hand structure or the need to adjust the pitch during operation, which makes it unsuitable for high-speed transport of the workpiece 20, do not occur. Accordingly, with this embodiment, the excellent effect of being able to accurately position the workpiece 20 at the desired input position in the container 50 without increasing the working time is obtained.

[0073] In this case, the number of gripping parts 81 to 85 on the hand 80 is "5," which is the same number as the number of workpieces 20 lined up along the second direction B2 in the aligned state. With this configuration, the maximum number of workpieces 20 lined up along the second direction B2 of the container 50 can be picked up in a single operation, and these workpieces 20 can be arranged all at once so that they are lined up along the second direction B2 of the container 50. Therefore, with the above configuration, by performing this operation only three times, the same number as the number of workpieces 20 lined up along the first direction B1, it is possible to place workpieces 20 in all input positions in the container 50, that is, to fill the container 50 with all workpieces 20. Accordingly, this embodiment maximizes the effect of reducing working time.

[0074] In this case, the motion control unit 92 controls the movement of the robot arm 40 so that, after placing the workpiece 20 at the input position, one of the multiple gripping units 81 to 85, specifically gripping unit 81, is positioned above the acquisition position. In this way, the robot arm 40 can immediately move on to the operation of picking up the first workpiece 20, that is, the first pick operation, after placing all the workpieces 20 at the input position, i.e., after completing the placing operation. Therefore, according to this embodiment, the robot arm 40 can transition from the placing operation to the first pick operation with almost no delay, and as a result, the work time can be further reduced.

[0075] (Second Embodiment) The second embodiment will be described below with reference to Figures 20 to 26. The production system 100 of this embodiment differs from the production system 10 of the first embodiment in that it has two containers 50. Specifically, in the production system 100, containers 50 are arranged on both the right and left sides in the flow direction A1 of the conveyor 30. In this configuration, the container 50 arranged on the right side is designated as the first container 50A, and the container 50 arranged on the left side is designated as the second container 50B.

[0076] In this case, the motion control unit 92 can perform a first acquisition operation and a second acquisition operation. The first acquisition operation involves moving the hand 80 from right to left along the alignment direction C1, with the hand 80 oriented so that the flow direction A1 and the alignment direction C1 are perpendicular to each other, and sequentially picking up the workpiece 20 with each of the gripping units 81 to 85. The second acquisition operation involves moving the hand 80 from left to right along the alignment direction C1, with the hand 80 oriented so that the flow direction A1 and the alignment direction C1 are perpendicular to each other, and sequentially picking up the workpiece 20 with each of the gripping units 81 to 85.

[0077] If the input position set by the position setting unit 91 is a position in the first container 50A, the operation control unit 92 can execute a second acquisition operation to take the workpieces 20 and then collectively place all the taken workpieces 20 at the input position in the first container 50A. If the input position set by the position setting unit 91 is a position in the second container 50B, the operation control unit 92 can execute a first acquisition operation to take the workpieces 20 and then collectively place all the taken workpieces 20 at the input position in the second container 50B.

[0078] Next, a specific example of the pick-and-place operation, particularly the picking operation, according to the configuration of this embodiment will be described. Note that the same operations as those described in the first embodiment can be used for the placing operation, so its description will be omitted here.

[0079] [1] Picking operation when placing workpiece 20 into the second container 50B In this case, the motion control unit 92 performs a first acquisition operation to sequentially pick up the workpiece 20 with each of the gripping units 81 to 85. The first acquisition operation is the same as the pick operation in the first embodiment, that is, the operation shown in Figures 3 to 7. In this case, since the second container 50B is positioned so that the second direction B2 is aligned with the flow direction A1 of the conveyor 30, when performing a placing operation, it is necessary to rotate the orientation of the hand 80 by 90 degrees from the orientation during the pick operation.

[0080] Therefore, after the gripping units 81 to 85 have gripped the five workpieces 20, the motion control unit 92 rotates the orientation of the hand 80 by 90 degrees from the orientation during the picking operation, either before moving the arm tip toward the second container 50B, after moving the arm tip toward the second container 50B, or while moving the arm tip toward the second container 50B. As a result, as shown in Figure 20, the alignment direction C1 of the hand 80 becomes aligned with the second direction B2 of the second container 50B.

[0081] [2] Picking operation when placing workpiece 20 into the first container 50A In this case, the motion control unit 92 executes a second acquisition operation to sequentially acquire the workpiece 20 with each of the gripping units 81 to 85. First, as shown in Figure 21, the motion control unit 92 controls the movement of the robot arm 40 so that it is in an initial position where the gripping unit 85 is located above the acquisition position. Then, when the workpiece 20 reaches the acquisition position, that is, the position directly below the gripping unit 85, the motion control unit 92 grips the workpiece 20 with the gripping unit 85.

[0082] Next, as shown in Figure 22, the motion control unit 92 controls the movement of the robot arm 40 so that the gripping unit 84 is positioned above the acquisition position. Then, the motion control unit 92 grips the workpiece 20 with the gripping unit 84 when the workpiece 20 reaches a position directly below the gripping unit 84. Next, as shown in Figure 23, the motion control unit 92 controls the movement of the robot arm 40 so that the gripping unit 83 is positioned above the acquisition position. Then, the motion control unit 92 grips the workpiece 20 with the gripping unit 83 when the workpiece 20 reaches a position directly below the gripping unit 83.

[0083] Next, as shown in Figure 24, the motion control unit 92 controls the movement of the robot arm 40 so that the gripping unit 82 is positioned above the acquisition position. Then, the motion control unit 92 grips the workpiece 20 with the gripping unit 82 when the workpiece 20 reaches a position directly below the gripping unit 82. Next, as shown in Figure 25, the motion control unit 92 controls the movement of the robot arm 40 so that the gripping unit 81 is positioned above the acquisition position. Then, the motion control unit 92 grips the workpiece 20 with the gripping unit 81 when the workpiece 20 reaches a position directly below the gripping unit 81.

[0084] As a result of this picking operation, five workpieces 20 are gripped by the gripping sections 81 to 85 of the hand 80. In this case as well, the workpieces 20 are transported in a direction such that the sides with the seal-cut sections 21 and 22 are perpendicular to the flow direction A1, and the hand 80 is positioned so that the flow direction A1 and the alignment direction C1 are perpendicular to each other when picking up the workpieces 20. As shown in Figure 8, the five workpieces 20 gripped by the hand 80 are naturally arranged so that the sides without the seal-cut sections 21 and 22 are adjacent to each other.

[0085] In this case, since the first container 50A is positioned so that its second direction B2 aligns with the flow direction A1 of the conveyor 30, the orientation of the hand 80 needs to be rotated 90 degrees from the orientation during the picking operation when performing a placing operation. Therefore, after the gripping units 81 to 85 each grip the five workpieces 20, the motion control unit 92 rotates the orientation of the hand 80 90 degrees from the orientation during the picking operation either before moving the arm tip toward the first container 50A, after moving the arm tip toward the first container 50A, or while moving the arm tip toward the first container 50A. As a result, as shown in Figure 26, the alignment direction C1 of the hand 80 aligns with the second direction B2 of the first container 50A.

[0086] As described above, in this embodiment, the first container 50A is positioned on the right side in the flow direction A1, and the second container 50B is positioned on the left side. Furthermore, the operation control unit 92 in this embodiment is capable of performing a first acquisition operation in which the hand 80 is moved from the right side to the left side and the workpiece 20 is sequentially picked up by each of the gripping parts 81 to 85, and a second acquisition operation in which the hand 80 is moved from the left side to the right side and the workpiece 20 is sequentially picked up by each of the gripping parts 81 to 85.

[0087] In the above configuration, if the input position is in the first container 50A, the operation control unit 92 executes a second acquisition operation to pick up the workpieces and places all the picked workpieces 20 together at the input position in the first container 50A. In this way, when the workpieces 20 have been picked up, the position of the hand 80 will be closer to the first container 50A, allowing for a smooth transition from the pick operation to the place operation.

[0088] Furthermore, in the above configuration, if the input position is in the second container 50B, the operation control unit 92 executes the first acquisition operation to pick up the workpieces 20 and places all the picked workpieces 20 together at the input position in the second container 50B. In this way, when the workpieces 20 have been picked up, the position of the hand 80 will be closer to the second container 50B, allowing for a smooth transition from the picking operation to the placing operation. Therefore, according to this embodiment, the effect is obtained in which the work time can be further reduced when containers 50 are arranged on both the right and left sides in the flow direction A1 of the conveyor 30.

[0089] (Other embodiments) It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, and can be arbitrarily modified, combined, or expanded without departing from its essence. The numerical values ​​and other figures shown in each of the above embodiments are illustrative examples and are not limiting.

[0090] The gripping parts 81-85 of the hand 80 are not limited to those equipped with a suction mechanism for adsorbing and holding the workpiece 20; various types can be used, such as those equipped with a chuck for gripping and holding the workpiece 20. The number of gripping parts of the hand 80 may be different from the number of workpieces 20 that are aligned along the second direction B2 of the container 50 in the aligned state.

[0091] The alignment state may include a state in which four or more workpieces 20 are arranged along the first direction B1 of the container 50 such that the sides with seal-cut portions 21 and 22 are adjacent to each other, and can be appropriately changed depending on the size of the container 50 and the size of the workpieces 20. For example, 20 workpieces 20 may be arranged in the container 50 in a 5x4 alignment.

[0092] However, if this is done, the following modifications should be made. Here, the two columns at both ends will be referred to as the 1st column and the 4th column, respectively, and the two columns in between the ends will be referred to as the 2nd column and the 3rd column, respectively. In this case, the placing operation when the input positions of the four workpieces 20 arranged along the 1st direction B1 are set by the 1st setting method will be as follows. That is, the robot arm 40 first places the workpiece 20 at the input position of the 1st column, then places the workpiece 20 at the input position of the 4th column, then places the workpiece 20 at the input position of one of the 2nd and 3rd columns, and finally places the workpiece 20 at the input position of the other of the 2nd and 3rd columns.

[0093] With this loading order, when placing workpieces 20 at loading positions in the second and third rows of container 50, there will be already placed workpieces next to those loading positions. Therefore, if a normal approach motion is used when placing workpieces 20 at loading positions in the second and third rows, a repulsive force caused by interference between unplaced and already placed workpieces may result in a positional shift where the unplaced workpieces are moved away from the desired loading position.

[0094] Therefore, in the placing operation when the input positions of the four workpieces 20 arranged along the first direction B1 are set by the first setting method, when placing the workpieces 20 at the input positions in the second and third rows of the container 50, the operation control unit 92 may place the workpieces 20 by bringing the unplaced workpieces into contact with the already placed workpieces, causing the seal cut portions 21 and 22 of the unplaced workpieces and the seal cut portions 21 and 22 of the already placed workpieces to fold toward the bottom of the container 50, and then placing the unplaced workpieces at the input positions. More specifically, it may place the workpieces 20 by an oblique approach operation. In this way, misalignment is suppressed when placing the workpieces 20 at the input positions in the second and third rows of the container 50.

[0095] The hand 80 is not limited to having multiple gripping parts 81 to 85, and may have only one gripping part. The workpiece 20 may be any pillow packaging having seal-cut portions at least at both ends, for example, a pillow packaging with seal-cut portions on all four sides. Furthermore, the contents of the workpiece 20 are not limited to confectionery, but may include, for example, bread or frozen food. Even if the contents of the workpiece 20 are heavier than confectionery, such as bread or frozen food, the aforementioned misalignment problem will still occur to some extent, making the present invention beneficial.

[0096] The present invention is not limited to a robot arm control system comprising a controller 90 for a robot arm 40 applied to production systems 10, 100, but can be applied to robot arm control systems in general that control a robot arm that performs the task of loading workpieces, which are pillow-packaged products having seal-cut portions at least at both ends, into a rectangular container having four sides in a plan view, in an aligned state. [Explanation of Symbols]

[0097] 20...Workpiece, 21, 22...Seal cutting section, 30...Conveyor, 40...Robot arm, 50...Container, 50A...First container, 50B...Second container, 51~54...Edge, 80...Hand, 81~85...Gripping section, 90...Controller, 91...Position setting section, 92...Motion control section, A1...Flow direction, B1...First direction, B2...Second direction, C1...Alignment direction.

Claims

1. A robot arm control system for controlling a robot arm that performs the task of loading workpieces, which are pillow-packaged products having seal-cut portions at least at both ends, into a rectangular container having four sides in a plan view, in an aligned manner. If we define the first direction as the direction along the first and second sides, which are two of the four sides that are opposite to each other, and the second direction as the direction along the third and fourth sides, which are the two sides other than the first and second sides, The aforementioned alignment state includes a state in which a plurality of workpieces are arranged along the first direction such that the sides on which the seal-cut portions are provided are adjacent to each other. A position setting unit for setting the placement position of the workpiece in the container, An motion control unit controls the movement of the robot arm to pick up the workpiece at a predetermined acquisition position and to place the picked-up workpiece at the input position set by the position setting unit, Equipped with, The operation control unit is a control system for a robot arm that, when the input position is adjacent in a first direction to a previously placed workpiece which is a workpiece already placed in the container, brings the unplaced workpiece which is to be placed in contact with the previously placed workpiece so that the seal cut portion of the unplaced workpiece and the seal cut portion of the previously placed workpiece are folded toward the bottom of the container, and then places the unplaced workpiece in the input position.

2. The control system for a robot arm according to claim 1, wherein, when the input position is adjacent to the already placed workpiece in the first direction, the operation control unit brings the seal cut portion of the unplaced workpiece into contact with the seal cut portion of the already placed workpiece, thereby causing the seal cut portion of the unplaced workpiece and the seal cut portion of the already placed workpiece to fold toward the bottom of the container, and then places the unplaced workpiece at the input position.

Images