Workpiece picking method and workpiece picking system

Abstract

A workpiece pickup method picks up workpieces supplied to a supply worktable in a scattered state, the worktable being larger than a shooting range corresponding to a view angle of a shooting unit, the workpiece pickup method including: a step (a) of performing pickup processing in each of a plurality of regions obtained by dividing the supply worktable based on the shooting range, the pickup processing selecting a workpiece that can be picked up based on an image obtained by shooting the region by the shooting unit and causing a pickup unit to perform pickup; a step (b) of obtaining, for each region, a remaining number of workpieces remaining after the pickup processing; a step (c) of, based on the remaining number of workpieces of each region, re-supplying workpieces to the supply worktable and performing a scattering operation for scattering workpiece blocks or performing the scattering operation without re-supplying workpieces; and a step (d) of performing pickup processing after the scattering operation in a maximum region in which the remaining number of workpieces of each region obtained after the pickup processing is the largest.

Description

Technical Field

[0001] This specification discloses the workpiece picking method and the workpiece picking system. Background Technology

[0002] Conventional devices have been proposed that use an imaging unit to photograph workpieces supplied to a supply table in a dispersed state, select workpieces that can be picked up, and have a robot pick them up. For example, in Patent Document 1, a structure is provided that can cause the entire plate serving as the supply table to vibrate uniformly. By vibrating, the workpieces are dispersed across the entire surface of the plate, and then the robot picks them up, thereby effectively utilizing the entire surface of the plate to efficiently pick up the workpieces.

[0003] Existing technical documents

[0004] Patent Document 1: WO2019 / 097650A1 Summary of the Invention

[0005] The problem that the invention aims to solve

[0006] Here, sometimes the supply worktable (plate) is larger than the shooting range corresponding to the viewing angle of the imaging unit. In this case, if an imaging unit with a larger shooting range is used to match the supply worktable, it lacks versatility and is disadvantageous in terms of cost. Alternatively, images can be captured in multiple areas obtained by dividing the supply worktable based on the shooting range, and the captured images can be combined to create a complete image, but this increases the burden of image processing. Therefore, it is conceivable to perform processing by capturing images of each area and picking up the workpiece, but there are cases where the images may be taken in areas where there are no workpieces depending on the distribution of the workpieces, which may reduce processing efficiency.

[0007] The main objective of this disclosure is to efficiently pick up workpieces from a supply worktable that is larger than the shooting range of the shooting unit.

[0008] Technical solutions for solving the problem

[0009] In order to achieve the above-mentioned main objectives, the present disclosure adopts the following scheme.

[0010] The first workpiece picking method disclosed herein is a workpiece picking method for picking up workpieces supplied to a supply worktable in a scattered state, wherein the supply worktable is larger than the shooting range corresponding to the viewing angle of the imaging unit, and the workpiece picking method includes the following steps: step (a) performing picking processing on each of a plurality of regions obtained by dividing the supply worktable based on the shooting range, wherein in the picking processing, workpieces that can be picked up are selected based on images obtained by the imaging unit from the regions and the picking unit picks them up; step (b) obtaining the remaining number of workpieces remaining after the picking processing for each region; step (c) resupplying workpieces to the supply worktable based on the remaining number of workpieces in each region and performing a scattering action to scatter the workpiece blocks, or performing the scattering action without resupplying workpieces; and step (d) performing the picking processing after the scattering action on the region with the largest number of remaining workpieces in each region obtained after the picking processing.

[0011] In the first workpiece picking method disclosed herein, based on the remaining number of workpieces in each region after the picking process, workpieces are either resupplied to the supply table and a scattering action is performed, or a scattering action is performed without resuppliing workpieces. Furthermore, in the regions with the most workpieces after the picking process, picking process is performed after the scattering action. Regions that were the most numerous before the scattering action are likely to still have a relatively large number of workpieces after the scattering action; therefore, inefficient processes such as picking areas with fewer pickable workpieces and unnecessary processes such as taking images of areas without workpieces can be avoided. Therefore, workpieces can be picked up efficiently from the supply table, which is larger than the imaging range of the imaging unit. Attached Figure Description

[0012] Figure 1 This is a schematic diagram showing the structure of the operating system 10.

[0013] Figure 2 This is a block diagram showing the electrical connections of the operating system 10.

[0014] Figure 3 This is an explanatory diagram showing the relationship between the shooting range FC of camera 45 and the supply table 25.

[0015] Figure 4 This is a flowchart representing an example of a job processing procedure.

[0016] Figure 5 This is a flowchart illustrating an example of workpiece picking and processing.

[0017] Figure 6 This is an illustrative diagram illustrating an example of the change in the remaining quantity R of the workpiece.

[0018] Figure 7 This is a flowchart representing the job processing procedure for a variant example. Detailed Implementation

[0019] The embodiments of this disclosure will now be described using the accompanying drawings. Figure 1 This is a schematic diagram showing the structure of the operating system 10. Figure 2 This is a block diagram showing the electrical connections of the operating system 10. Additionally, Figure 1 In the diagram, the left and right directions are the X-axis, the front and back directions are the Y-axis, and the up and down directions are the Z-axis.

[0020] like Figure 1 , Figure 2 As shown, the work system 10 includes: a workpiece supply device 20 (20A, 20B), a pallet conveying device 30, a work robot 40, a camera 45, and a control device 50. The work system 10 uses the work robot 40 to perform predetermined tasks such as picking up and placing workpieces. For example, the work robot 40 of the work system 10 performs the following tasks: picking up a bolt B (first workpiece) supplied in a loose state and placing it in an upright position with its head facing down on the pallet T; picking up a washer W (second workpiece) supplied in a loose state and arranging the washer W into the threaded portion (bar-shaped portion) of the bolt B on the pallet T. Furthermore, the work system 10 is not limited to picking up and placing; for example, it can pick up workpieces and install them onto an object, or sequentially pick up the supplied workpieces using the work robot 40.

[0021] In the work system 10 of this embodiment, a first workpiece supply device 20A for supplying bolts B and a second workpiece supply device 20B for supplying washers W are provided as workpiece supply devices 20. The first workpiece supply device 20A and the second workpiece supply device 20B have the same structure; therefore, only the workpiece supply device 20 will be described below. Furthermore, the workpiece supply device 20 can be a device that supplies various workpieces such as electronic components in addition to various mechanical components such as bolts B and washers W. Furthermore, the work system 10 is not limited to having two workpiece supply devices 20A and 20B; it may also have only one workpiece supply device 20. Additionally, the work system 10 may also include a work robot 40 corresponding to the number of workpiece supply devices 20.

[0022] The workpiece supply device 20 includes: a feed section 22 for forward conveying workpieces fed by an operator or a supply robot (not shown); a supply table 25 configured to allow the workpiece to be picked up by the operation robot 40; and a vibration device 26 (see reference) for vibrating the supply table 25 up and down. Figure 2 ).

[0023] The feed section 22 has a first inclined section 22a, a second inclined section 22b, and a third inclined section 22c, and is equipped with a lifting device 23 (see reference) for raising and lowering the second inclined section 22b. Figure 2 The first inclined portion 22a, the second inclined portion 22b, and the third inclined portion 22c are arranged in this order from the rear, all inclined downwards towards the front. When the lifting device 23 is not in operation, the second inclined portion 22b is located at the lower end of the lifting range, and its upper surface is continuous with the upper surface of the first inclined portion 22a. When the lifting device 23 is in operation, it is located at the upper end of the lifting range, and its upper surface is continuous with the upper surface of the third inclined portion 22c. The third inclined portion 22c is configured to extend upwards towards the rear end of the supply table 25. Although not shown in the figure, a rear wall extending downwards from the rear end of the second inclined portion 22b is provided, so that even if the second inclined portion 22b rises, the workpiece on the first inclined portion 22a is blocked by the rear wall of the second inclined portion 22b. Similarly, a rear wall extending downwards from the rear end of the third inclined portion 22c is provided, so that the workpiece on the lower end of the second inclined portion 22b is blocked by the rear wall of the third inclined portion 22c.

[0024] Workpieces fed into the workpiece supply device 20 flow forward and downward on the first inclined section 22a and remain on the second inclined section 22b. When the upper surface of the second inclined section 22b, which has been raised by the operation of the lifting device 23, becomes continuous with the upper surface of the third inclined section 22c, the workpieces remaining on the second inclined section 22b flow towards the third inclined section 22c and fall onto the supply table 25. In this way, the workpiece supply device 20 supplies workpieces to the supply table 25 in a dispersed state, enabling the work robot 40 to pick up the workpieces on the supply table 25. In addition, the workpiece supply device 20 can vibrate the workpieces on the supply table 25 by driving the vibration device 26 to disperse (disassemble) the workpiece blocks. This action is called the dispersing action.

[0025] The pallet conveying device 30 has a pair of conveyor belts 32 spaced apart in the front-to-back direction (Y-axis direction) and mounted in the left-to-right direction (X-axis direction). The pallet conveying device 30 transports the pallet T to the working area of ​​the work robot 40 by driving the conveyor belts 32.

[0026] The work robot 40 has, for example, a vertical multi-joint robot arm 42 and an end effector 44 that is detachably mounted on the end link of the robot arm 42. The end effector 44 is a component for picking up workpieces and consists of an electromagnetic chuck, a mechanical chuck, a suction nozzle, etc., and is appropriately selected to match the shape and material of the workpiece.

[0027] Additionally, a camera 45 for capturing images is mounted on the robotic arm 42. The camera 45 has a single-focus lens and a constant field of view. The camera 45 captures images of the workpiece to identify its position, quantity, and orientation when it is supplied to the supply table 25, or it captures images of the pallet T to identify its position when it is transported by the pallet conveyor 30.

[0028] Figure 3 This is an explanatory diagram showing the relationship between the shooting range FC of camera 45 and the supply table 25. Figure 3 In the diagram, the area of ​​the supply table 25 as viewed from above is shown by a solid line, and the shooting range FC is shown by a dashed line. Additionally, the state where multiple washers W are supplied to the supply table 25 is illustrated. The shooting range FC is determined based on the viewpoint of the camera 45 and covers the area on the supply table 25. In this embodiment, it roughly corresponds to the area obtained by dividing the supply table 25 into left and right sections. Therefore, two shots are required to capture the entire area of ​​the supply table 25 using the camera 45. That is, the camera 45 needs to capture the first area when it is positioned above the first area (e.g., the left side area) due to the operation of the robot arm 42, and capture the second area when it is positioned above the second area (e.g., the right side area) due to the operation of the robot arm 42.

[0029] like Figure 2 As shown, the control device 50 is configured as a microprocessor centered on a CPU 51. In addition to the CPU 51, it also includes a ROM 52 for storing various control programs, a RAM 53 used as a work area, an HDD 54 for storing various data, and input / output ports (not shown). Detection signals from sensors (not shown) on the workpiece supply device 20, pallet conveyor 30, and work robot 40, as well as images captured by the camera 45, are input to the control device 50. Furthermore, control signals are output from the control device 50 to the workpiece supply device 20, pallet conveyor 30, work robot 40 (robot arm 42 and end effector 44), camera 45, etc.

[0030] Next, the operation of the work system 10 configured in this way will be described, in particular the process of photographing the workpieces supplied to the worktable 25, selecting the workpieces that can be picked up, and having the work robot 40 pick up the workpieces. Figure 4 This is a flowchart illustrating an example of a job processing procedure. Furthermore, as another example of job processing, the procedure for picking up a washer W is explained, using the left side of the supply table 25 as the first area and the right side as the second area.

[0031] exist Figure 4In the job processing procedure, the CPU 51 of the control device 50 first controls the work robot 40 to move the camera 45 to the shooting position of the first area (S100), and performs the workpiece picking process in the first area (S105). If the workpiece picking process in the first area is completed, the CPU 51 controls the work robot 40 to move the camera 45 to the shooting position of the second area (S110), and performs the workpiece picking process in the second area (S115). The workpiece picking processes in S105 and S115 will be described below. Figure 5 This is a flowchart illustrating an example of the workpiece picking process. Furthermore, although the object areas being processed differ, the workpiece picking process in S105 and S115 is the same; therefore, a shared flowchart will be used for explanation.

[0032] exist Figure 5 In the workpiece picking process, CPU 51 first controls camera 45 to capture an image of the target area (S200). In S105, an image of the first area is captured, and in S115, an image of the second area is captured. Next, CPU 51 processes the captured images and identifies the number and position of workpieces, etc. (S205). In addition, if the workpiece to be picked up is bolt B, the workpiece's posture, etc., is also identified. Next, CPU 51 determines whether there is a workpiece that can be picked up (S210). In S210, for example, since other workpieces do not overlap and are not close to other workpieces, the workpiece that can be held by an end effector 44 such as a mechanical chuck can be picked up. If CPU 51 determines that there is a workpiece that can be picked up, it picks up the workpiece and places it in a predetermined position (S215), increments the pick count by 1 (S220), and returns to S210. In the case of washer W, in S215, it is placed in the manner described above, inserted into the threaded portion of bolt B.

[0033] Furthermore, if CPU51 determines in S210 that there are no workpieces that can be picked up, it stores the remaining number of workpieces R (S225) and ends the workpiece picking process. The remaining number of workpieces R is calculated by subtracting the number of workpieces picked up in S220 from the number of workpieces identified in S205. Additionally, the remaining number R stored in the workpiece picking process of the first region in S105 is designated as the remaining number R1, and the remaining number R stored in the workpiece picking process of the second region in S115 is designated as the remaining number R2.

[0034] Figure 6 This is an illustrative diagram illustrating an example of the change in the remaining quantity R of the workpiece. Figure 6 (a) shows from Figure 3The state is the state after the workpiece picking process of the first region (left region) in S105 has been executed. For example, the remaining quantity R1 in the first region becomes 6. In addition, Figure 6 (b) shows from Figure 6 The state of (a) is the state after the workpiece picking process of the second region (right region) of S115 is executed, for example, the remaining quantity R2 of the second region becomes the value 8.

[0035] exist Figure 4 In the job processing procedure, when CPU 51 executes the workpiece picking process in S115, it calculates the total quantity Sa (S120) as the total quantity S of the remaining quantity R. The total quantity Sa is the total number of workpieces remaining on the supply table 25 after the workpiece picking processes have been performed in each area, and is the sum of the remaining quantity R1 in the first area and the remaining quantity R2 in the second area. Furthermore, Figure 6 In the example, it becomes the value 14 ( Figure 6 (b) Next, the CPU 51 determines whether the total quantity Sa is greater than or equal to the predetermined quantity Sref (S125). The predetermined quantity Sref can be a value that the operator can appropriately set according to the size of the supply worktable 25, the type of workpiece, etc., or it can be a fixed value. If the CPU 51 determines that the total quantity Sa is greater than or equal to the predetermined quantity Sref, there are too many workpieces remaining. Therefore, it controls the workpiece supply device 20 to perform the workpiece scattering operation on the supply worktable 25 without resupplying workpieces to the supply worktable 25 (S130), and proceeds to S140. On the other hand, if the CPU 51 determines that the total quantity Sa is not greater than or equal to the predetermined quantity Sref and is less than Sref, it controls the workpiece supply device 20 to perform the workpiece scattering operation after resupplying workpieces to the supply worktable 25 (S135), and proceeds to S140.

[0036] Next, when calculating the total quantity S (Sa or Sb described later), CPU51 distinguishes between the majority regions with a larger remaining quantity R and the minority regions with a smaller remaining quantity R (remaining quantity Rf) (S140). Figure 6 In the example, the remaining quantity R2 in the second region is greater than the remaining quantity R1 in the first region. Figure 6Therefore, the second region becomes the majority region, and the first region becomes the minority region. Furthermore, in S140, the CPU 51 stores the value 6 of the remaining quantity R1 in the first region as the remaining quantity Rf in the minority region. Then, the CPU 51 controls the work robot 40 to move the camera 45 towards the shooting position of the majority region (S145), performing workpiece picking processing for the majority region (S150). That is, before performing the workpiece scattering action in S130 and before performing the workpiece supply and scattering action in S135, the CPU 51 selects the majority region with the larger remaining quantity R as the next processing target and performs workpiece picking processing. Additionally, sometimes workpieces move between regions due to the scattering action, but even if workpieces move, it can be said that the movement from the first region to the second region and the movement from the second region to the first region occur in the same way. Therefore, in S140 and S150, the change in the remaining quantity R caused by the movement of workpieces between regions is not specifically considered, and the majority region after the previous workpiece picking processing is selected as the next processing target. Furthermore, the workpiece picking process in S150 is based on the same principle as in S105 and S115. Figure 5 The process is executed using a flowchart, therefore, explanations are omitted. Additionally, the remaining quantity R after the workpiece picking process in S150 is set as the remaining quantity Rm. Figure 6 In the example, the second region is the majority region; therefore, the workpiece picking process for the second region is performed. Figure 6 (c) and (d)). In addition, the workpiece picking process for the first region, which is a minority region, is not performed in S140, so the remaining quantity Rf remains at the value 6.

[0037] After the workpiece picking process S150 is executed, CPU 51 calculates the total quantity Sb (S155) based on the total quantity S of the remaining quantity R. The total quantity Sb is the sum of the remaining quantity Rm after workpiece picking processing in most areas and the remaining quantity Rf in a few areas. Figure 6 In the example, the remaining quantity Rm of the second region, which is the majority region, is, for example, 4, and the remaining quantity Rf of the first region, which is the minority region, remains at 6. Therefore, the total quantity Sb becomes 10. Figure 6 (d)). In this example, the remaining quantity Rf in the first region is greater than the remaining quantity Rm in the second region.

[0038] Next, CPU 51 determines whether the total quantity Sb is greater than or equal to the predetermined quantity Sref (S160). The predetermined quantity Sref in S160 is the same as the predetermined quantity Sref in S125, but it can also be a different number. If CPU 51 determines that the total quantity Sb is greater than or equal to the predetermined quantity Sref, it controls the workpiece supply device 20 to perform the workpiece scattering operation on the supply table 25 without resupplying workpieces to the supply table 25 (S165), and proceeds to S140. Alternatively, if CPU 51 determines in S160 that the total quantity Sb is not greater than or equal to the predetermined quantity Sref and is less than Sref, it controls the workpiece supply device 20 to resupply workpieces to the supply table 25 and then performs the workpiece scattering operation (S170), and proceeds to S100. That is, in this case, the picking process is performed again in the order of the first region and the second region.

[0039] In S140, executed after S165, CPU 51, when calculating the total quantity Sb, distinguishes between the majority of regions with a larger remaining quantity R and the minority of regions with a smaller remaining quantity R (remaining quantity Rf), and executes the processing below S145. That is, for the majority of regions where the total quantity Sb was calculated in S155, workpiece picking processing is performed. Figure 6 In the example, such as Figure 6 As shown in (d), the first region becomes the majority region and the second region becomes the minority region. Therefore, the remaining quantity Rf becomes the value 4 of the remaining quantity R of the second region, and the workpiece picking process of the first region is executed. Furthermore, although the illustration is omitted, if the picking process of the first region is executed in S145 and S155, the remaining quantity R of the first region becomes the remaining quantity Rm. In S155, the CPU 51 calculates the total quantity Sb of this remaining quantity Rm and the remaining quantity Rf (value 4) of the second region. Thus, while selecting the target region (majority region) and performing workpiece picking processing in the target region, the required number of workpieces are picked from the supply table 25, and then the job processing program ends.

[0040] Here, the correspondence between the structural elements of this embodiment and the structural elements of this disclosure is clarified. The S105 and S115 of the operation processing procedure of this embodiment (excluding...) Figure 2 S225 is equivalent to step (a), when performing S105 and S115. Figure 2 S225 is equivalent to step (b), S120 to S135 of the job processing procedure are equivalent to step (c), and S140, S145, and S150 of the job processing procedure (excluding) Figure 2 S225) is equivalent to step (d). When performing S150... Figure 2S225 corresponds to step (e), and S155 to S170 of the job processing procedure correspond to step (f). In addition, camera 45 corresponds to the shooting unit, the supply table 25 of the workpiece supply device 20 corresponds to the supply table, the work robot 40 corresponds to the picking unit, the feed unit 22 (lifting device 23) of the workpiece supply device 20 corresponds to the supply unit, the vibration device 26 of the workpiece supply device 20 corresponds to the dispersing unit, and the control device 50 corresponds to the control unit.

[0041] As explained above, in the workpiece picking method of this disclosure, workpieces are supplied and a scattering action is performed based on the remaining number R (R1, R2) of workpieces in each region after workpiece picking processing, or a scattering action is performed without supplying workpieces. Furthermore, the majority of regions with a relatively large remaining number R of workpieces before the scattering action (when calculating the total number S) are selected as targets for workpiece picking processing after the scattering action. Since there is a higher probability that there will be a relatively large number of workpieces in the majority of regions after the scattering action, performing workpiece picking processing in the majority of regions after the scattering action prevents inefficient workpiece picking processing in regions with fewer workpieces and unnecessary image processing in regions without workpieces. Additionally, it eliminates the need for separate image captures of each region after the scattering action to determine the target region, thus shortening the cycle time.

[0042] Furthermore, based on the remaining quantity Rm after workpiece picking in most areas and the remaining quantity Rf in a few areas, a dispersal operation is performed after workpieces are supplied, or a dispersal operation is performed without supplying workpieces. That is, after workpiece picking in most areas, images of the few areas are not captured and the process is moved to the next step, thus eliminating the need for image capture and shortening the cycle time.

[0043] Furthermore, if a workpiece is picked up and processed in most areas, followed by a workpiece distribution operation, the process proceeds to S100. Therefore, when there is a high probability that workpieces can be picked up in each area due to the supply of workpieces, workpiece picking processing in each area can be performed sequentially. On the other hand, if a workpiece is picked up and processed in most areas, followed by a distribution operation without the supply of workpieces, the process proceeds to S140, and then the majority of areas can be selected again for workpiece picking processing in those areas. Therefore, in cases where there may be areas with fewer pickable workpieces or areas without any workpieces due to the lack of workpiece supply, performing workpiece picking processing in most areas can prevent inefficient workpiece picking processing and unnecessary image processing.

[0044] Furthermore, this disclosure is not limited to the above-described embodiments in any way, and can be implemented in various ways as long as it falls within the technical scope of this disclosure, which is self-evident.

[0045] In the above-described embodiments, if the workpiece is picked up and then fed to the workpiece in most areas and then dispersed (if S170 is executed), the process proceeds to S100, but is not limited thereto. Figure 7 This is a flowchart illustrating the work processing procedure of a modified example. In this modified example, the work processing procedure differs from the implementation method in that it proceeds to S140 after S170, instead of S100. Therefore, if a scattering operation is performed in S165 and S170, a majority of areas can be selected again, and workpiece picking processing for those areas can be performed. That is, workpiece picking processing for a majority of areas can be repeatedly performed, thus preventing inefficient workpiece picking processing and unnecessary image capture for areas with few pickable works or areas without works.

[0046] In the implementation, for calculating the total quantity Sb in S155 after performing S165 and transitioning to S140, the remaining quantity R in most areas uses the actual remaining quantity Rm after the workpiece picking process, and the remaining quantity R in a few areas uses the remaining quantity Rf obtained before the dispersing action (when calculating the total quantity S), but is not limited to this. For example, CPU 51 can also capture images of a few areas using camera 45 and obtain the actual remaining quantity R. Furthermore, in the case where the transition to S140 occurs after S165 and S170 as described in the above-described variation, it can be done as follows: That is, after the dispersing action is performed in S165, the possibility of change in the remaining quantity R of each area is small; therefore, CPU 51 can use the remaining quantity Rf obtained before the dispersing action as the remaining quantity R of a few areas. On the other hand, when the workpiece supply and dispersing actions are performed in S170, the possibility of change in the remaining quantity R of each area is large; therefore, CPU 51 can capture images of a few areas using camera 45 and obtain the actual remaining quantity R.

[0047] In this implementation, the dispersing action is performed either without supplying workpieces or after supplying workpieces, based on the total number S (Sa, Sb) of the remaining quantity R in each region, but is not limited to these methods. The dispersing action can also be performed without supplying workpieces or after supplying workpieces, based on the remaining quantity R of one region (majority of regions) that will be processed next. Furthermore, the determination can be based on the total number S (Sa) of the remaining quantity R in each region in S125, or on the remaining quantity Rm of most regions in S160, or on the remaining quantity R (remaining quantity Rm) of one region.

[0048] In this embodiment, the supply workbench 25 is illustrated by dividing it into two regions: a first region and a second region. However, it is not limited to this and may also be divided into three or more regions. For example, the supply workbench 25 may be divided into three regions: a left region, a central region, and a right region.

[0049] In the case of dividing into n (n is a multiple) regions, it is done as follows: Figure 4 ( Figure 7 The operation procedure can be implemented as follows: First, in S100 to S115, workpiece picking is performed on each of the n regions. In S120, the total number Sa of the remaining quantity R after workpiece picking is calculated for each region. Then, in S125 to S135, similar to the implementation method, the total number Sa of the remaining quantity R is compared with a predetermined quantity Sref and S130 or S135 is performed. In S140, the majority region is identified as the region with the largest remaining quantity among the n regions, and the minority region is identified as the region that is not the largest region, i.e., the remaining (n-1) other regions. Then, in S145 and S150, workpiece picking is performed on the region with the largest quantity. In S155 to S170, the total number Sb of the remaining quantity Rm after workpiece picking is calculated for the region with the largest quantity and the remaining quantity Sb of the other regions. This total number Sb is compared with the predetermined quantity Sref and S165 or S170 is performed. When the supply worktable 25 is divided into three or more areas, taking images of each area takes longer than in the previous method. Therefore, by applying the processing disclosed herein, the inefficient workpiece picking process and unnecessary image taking are better prevented. In addition, it is not necessary to take images of each area separately after the dispersing action to determine the target area, thus eliminating unnecessary image taking and improving the cycle time.

[0050] In one embodiment, the workpiece supply device 20 includes a feed section 22 for conveying workpieces to the supply table 25 and a vibration device 26 for dispersing workpieces on the supply table 25, but is not limited thereto. Alternatively, the workpiece supply device 20 may include both the supply table 25 and the vibration device 26, with workpieces being directly supplied to the supply table 25 by a replenishment robot or the like. Alternatively, the workpiece supply device 20 may only include the supply table 25, with a robot such as a replenishment robot performing the dispersing action on the workpieces.

[0051] Here, the workpiece picking method of this disclosure can also be as follows. For example, the first workpiece picking method of this disclosure may include the following steps: step (e), obtaining the remaining number of workpieces remaining in the maximum region after the picking process in step (d); and step (f), based on the remaining number of workpieces obtained in other regions besides the maximum region before the scattering action and the remaining number of workpieces in the maximum region obtained in step (e), performing the scattering action after the picking process in step (d) either after resupplying workpieces to the supply table or without resupplying workpieces. In this way, after the picking process in the maximum region, images of other regions can be transferred to the next processing without capturing images of other regions, thus preventing unnecessary processing such as capturing images of regions where no workpieces exist.

[0052] Alternatively, in the first workpiece picking method of this disclosure, if the aforementioned scattering action is performed after workpiece resupply in step (f), the process proceeds to step (a); if the aforementioned scattering action is performed without workpiece resupply in step (f), the process proceeds to step (d). In this way, if there is a high probability that workpieces can be picked up in each area due to workpiece resupply, step (a) can be returned to sequentially perform picking processing for each area. Furthermore, if there are areas with few pickable workpieces or areas without workpieces due to the scattering action performed without workpiece resupply, picking processing is performed in the area with the most workpieces, thereby preventing unnecessary processing.

[0053] Alternatively, in the first workpiece picking method of this disclosure, when any of the aforementioned scattering actions in step (f) is performed, the process proceeds to step (d). This allows for repeated picking processing in the largest possible area, thus preventing unnecessary processing.

[0054] The second workpiece picking method disclosed herein is a workpiece picking method for picking up workpieces supplied to a supply worktable in a scattered state, wherein the supply worktable is larger than the shooting range corresponding to the viewing angle of the shooting unit, and the workpiece picking method includes the following steps: step (a) picking up each of two regions obtained by dividing the supply worktable based on the shooting range, wherein in the picking up process, workpieces that can be picked up are selected based on images obtained by the shooting unit of the regions and the picking unit picks them up; step (b) obtaining the remaining number of workpieces remaining after the picking up process for each region; step (c) if the total number of remaining workpieces in each region is less than a predetermined number, workpieces are resupplied to the supply worktable and a scattering action is performed to scatter the workpiece blocks; if the total number is greater than or equal to the predetermined number, the scattering action is performed without resuppliing workpieces; and step (d) in the majority of regions where the remaining number of workpieces in each region obtained after the picking up process is greater, the picking up process after the scattering action is performed.

[0055] In the second workpiece picking method disclosed herein, similar to the first workpiece picking method, the picking process after the scattering action is performed in a majority of areas where a large number of workpieces remain after the scattering action. Therefore, workpieces can be picked up efficiently from a supply worktable that is larger than the shooting range of the imaging unit. Furthermore, the steps of the first workpiece picking method can be added to the second workpiece picking method.

[0056] The workpiece picking system disclosed herein includes: an imaging unit; a supply table, larger than the imaging range corresponding to the viewing angle of the imaging unit; a supply unit for supplying workpieces to the supply table; a picking unit for picking up workpieces supplied to the supply table in a dispersed state; a dispersing unit for performing a dispersing action to disperse workpiece blocks on the supply table; and a control unit that controls the imaging unit and the picking unit to perform image acquisition based on images of multiple regions obtained by dividing the supply table based on the imaging range. The control unit controls the supply unit and the scattering unit to resupply workpieces to the supply worktable and perform a scattering action to scatter workpiece blocks based on the remaining number of workpieces in each of the aforementioned regions after the pick-up process, or to perform the scattering action without resupplying workpieces. The control unit controls the imaging unit and the picking unit to perform the pick-up process after the scattering action in the region with the largest number of remaining workpieces in each of the aforementioned regions obtained after the pick-up process.

[0057] In the workpiece picking system disclosed herein, similar to the first workpiece picking method described above, a picking process following a scattering action is performed in the area with the most pick-up processing. Therefore, workpieces can be efficiently picked up from a supply table larger than the imaging range of the imaging unit. Furthermore, functions similar to those in each step of the first workpiece picking method can also be added to the workpiece picking system.

[0058] Industrial availability

[0059] This disclosure can be used in the technical field of systems for picking up and configuring workpieces.

[0060] Explanation of reference numerals in the attached figures

[0061] 10...Working system; 20, 20A, 20B...Workpiece feeding device; 22...Feed section; 22a...First inclined section; 22b...Second inclined section; 22c...Third inclined section; 23...Lifting device; 25...Feeding worktable; 26...Vibration device; 30...Pattern conveying device; 32...Conveyor belt; 40...Working robot; 42...Robot arm; 44...End effector; 45...Camera; 50...Control device; 51...CPU; 52...ROM; 53...RAM; 54...HDD; B...Bolt; T...Pattern; W...Washer.

Claims

1. A workpiece picking method for picking up workpieces supplied to a supply table in a dispersed state, wherein the supply table is larger than the shooting range corresponding to the viewing angle of the imaging unit, and the workpiece picking method includes the following steps: Step (a) involves picking up workpieces in each of the multiple regions obtained by dividing the supply worktable based on the shooting range. In the picking up process, workpieces that can be picked up are selected and picked up by the picking unit based on images obtained by moving the shooting unit to the shooting position of each region. Step (b) is to obtain the remaining number of workpieces after the picking process for each of the regions. Step (c): If the total number of remaining workpieces in each region is less than a predetermined number, workpieces are resupplied to the supply table and a scattering action is performed to disperse the workpiece blocks; if the total number is greater than the predetermined number, the scattering action is performed without resuppliing workpieces. and Step (d) involves performing the scattering action on the region with the largest number of remaining workpieces in each region obtained after the picking process.

2. The workpiece picking method according to claim 1, wherein, The workpiece picking method includes the following steps: Step (e) obtains the remaining number of workpieces in the maximum region after the picking process in step (d); and Step (f) is performed after the picking process in step (d) based on the remaining number of workpieces obtained in areas other than the maximum area before the scattering action and the remaining number of workpieces in the maximum area obtained in step (e), either after the workpieces are resupplied to the supply table or without resuppliing the workpieces.

3. The workpiece picking method according to claim 2, wherein, If the dispersing action is performed after the workpiece is resupplied in step (f), proceed to step (a); if the dispersing action is performed without resuppliing the workpiece in step (f), proceed to step (d).

4. The workpiece picking method according to claim 2, wherein, When any of the spreading actions in step (f) is performed, proceed to step (d).

5. A workpiece picking method for picking up workpieces supplied to a supply table in a dispersed state, wherein the supply table is larger than the shooting range corresponding to the viewing angle of the imaging unit, and the workpiece picking method includes the following steps: Step (a) involves picking up workpieces in two regions obtained by dividing the supply worktable based on the shooting range. In this picking up process, workpieces that can be picked up are selected and picked up by the picking unit based on images obtained by shooting each region by moving the shooting unit to the shooting position of each region. Step (b) is to obtain the remaining number of workpieces after the picking process for each of the regions. Step (c): If the total number of remaining workpieces in each region is less than a predetermined number, workpieces are resupplied to the supply table and a scattering action is performed to disperse the workpiece blocks; if the total number is greater than the predetermined number, the scattering action is performed without resuppliing workpieces. and Step (d) involves performing the scattering action on the majority of regions where the number of remaining workpieces in each region is relatively large after the picking process.

6. A workpiece picking system, comprising: an imaging unit; a supply table, the size of which is larger than the imaging range corresponding to the viewing angle of the imaging unit; a supply unit for supplying workpieces to the supply table; a picking unit for picking up workpieces supplied to the supply table in a dispersed state; a dispersing unit for performing a dispersing action to disperse workpiece blocks on the supply table; and a control unit. The control unit controls the imaging unit and the pickup unit to perform pickup processing in each of the multiple regions obtained by dividing the supply worktable based on the imaging range. This is done by selecting and picking up workpieces based on images obtained by moving the imaging unit to the imaging position in each region. The control unit controls the supply unit and the dispersing unit to resupply workpieces to the supply table and perform a dispersing action to disperse the workpiece blocks when the total number of remaining workpieces in each region is less than a predetermined number; and to perform the dispersing action without resupplying workpieces when the total number is greater than the predetermined number. The control unit controls the shooting unit and the picking unit to perform the picking process after the scattering action in the area with the largest number of remaining workpieces in each area obtained after the picking process.

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