Sorting method for an automatic sorting process, and sorting device
Patent Information
- Application Number
- EP2023701373
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-02-18
- Filing Date
- 2023-01-19
- Publication Date
- 2024-12-25
- Estimated Expiration
- 2043-01-19
AI Technical Summary
Conventional sorting methods for workpieces in flatbed machine tools, such as laser cutting or punching machines, face process disruptions due to displaced, overlapping, or contaminated workpieces, leading to reduced process reliability, speed, and automation, as these disruptions are not recognized and require manual intervention.
A sorting method and device that create and analyze actual images of the removal area to identify process disruptions, allowing for automatic adaptation of the sorting process by initiating measures such as changing the removal order, cleaning, or adjusting gripper access, thereby bypassing or resolving disruptions.
This approach increases process reliability, speed, and automation by enabling the sorting method to react automatically to disruptions, reducing the need for manual intervention and preventing further disruptions.
Smart Images
Figure 1.1
Abstract
Description
[0001] Sorting method for automatic sorting and sorting device.
[0002] Background of the invention
[0003] The invention relates to a sorting method for automatically sorting workpieces arranged in a removal area of a flatbed machine tool, in particular a laser cutting machine or a punching machine, into a storage area after a sorting process. Furthermore, the invention relates to a sorting device.
[0004] Such a sorting method and device are typically used after the workpieces have been manufactured on a flatbed machine tool, with the workpieces being positioned in the removal area of the flatbed machine tool. For example, a production table of the flatbed machine tool, which serves to support the workpieces during production, is moved into the removal area. However, during the subsequent sorting of the workpieces, process disruptions can occur that impair or even prevent the intended sorting process.
[0005] Such process disruptions can occur, for example, due to shifted and / or overlapping workpieces, which can prevent a gripper from picking up the workpiece. Furthermore, particularly when using production tables with so-called support bars, a process disruption can occur in the form of a component tipping between the support bars or contamination of the support bars, for example, a production residue jammed between the support bars.
[0006] Such process disruptions are not detected in conventional sorting processes, which can prolong the sorting process due to unsuccessful attempts by the gripper to remove the workpieces. Furthermore, the gripper and / or the workpieces can be damaged as a result of the process disruption, for example, due to a collision between the gripper and the workpiece. This has a negative impact on process reliability and the speed of the sorting process. Furthermore, conventional sorting processes require the intervention of a specialist to respond appropriately to the process disruptions. This also adversely reduces the level of automation.
[0007] EP 3 514 639 A1 discloses a method for palletizing parts machined in a processing machine. In this method, the parts machined in the processing machine are moved to an unloading area by a gripping device and positioned at a storage location on a storage area in the unloading area. The storage area available in the unloading area and the storage location of the parts are determined by means of a detection device directed toward the unloading area and a data evaluation device.
[0008] DE 10 2016 120 131 A1 discloses a method for assisting an operator in a manual sorting process of workpieces arranged on a sorting table. A sorting signal is generated from a sorting image data set, which contains information about the type, position, and / or shape of at least one removed workpiece. In particular, it is known to determine the absolute position and / or contour of the parts and / or the sheet position by evaluating the sorting image data set. Object of the invention
[0009] It is an object of the invention to increase the process reliability, the process speed and the degree of automation for automatic sorting.
[0010] Description of the invention
[0011] This object is achieved according to the invention by a sorting method and a sorting device of the type mentioned at the outset, with the further characterizing features according to claim 1 and claim 10.
[0012] In other words, the object is achieved by a sorting method for automatically sorting workpieces arranged in a removal area of a flatbed machine tool, in particular a laser cutting machine or a punching machine, into a storage area after a sorting process; characterized by the steps:
[0013] - Creating at least one actual image that depicts the actual condition of the sampling area;
[0014] - Analyzing the actual map to identify process disruptions, whereby when a process disruption is identified, a measure to adapt the sorting process is automatically initiated.
[0015] The actual image depicts the actual state of the removal area of the flatbed machine tool. In other words, the actual image captures features of the removal area. The actual image is preferably a two-dimensional image of the removal area. For example, the actual image can depict a surface of the removal area that can be captured from a specific viewing angle, whereby the captured features, such as a change in the surface contour, can be depicted in the actual image.
[0016] Analyzing the actual image can include recognizing the features captured in the actual image. The features are preferably recognized by image processing of the actual image. Using the features recognized in the actual image, predetermined components (in particular, workpieces, workpiece supports) can be identified. For this purpose, characteristic features of the components to be identified are preferably provided. For example, by recognizing a cutting contour, a workpiece having this contour can be identified in the actual image.
[0017] According to the invention, a process disturbance can be identified by analyzing the actual map. In this case, it can be provided that properties are determined for the identified components and compared with predetermined reference properties. If a deviation is detected between the determined properties of the identified components and the reference properties, the process disturbance is considered to be identified. Preferably, the process disturbance is only identified once a predetermined degree of deviation has been determined.
[0018] A process disruption is defined here and below as an impairment of the sorting process that significantly disrupts or even makes sorting impossible. For example, but by no means exclusively, a process disruption can occur in the form of the following events.
[0019] "Missing part": In the case of a "missing part" process error, the workpiece to be removed by the gripper cannot be identified in the removal area. In this case, the gripper attempts to remove the workpiece in vain, which prolongs the sorting of the workpieces.
[0020] "Displaced workpiece": This can change the removal position of one or more workpieces, causing the gripper to move to an incorrect position when removing the workpiece. A skeleton can be considered here and below as one workpiece. Furthermore, the workpiece to be removed can overlap another workpiece. In all cases, access by the gripper can be unsafe or inadequate, which can damage the workpieces and / or the gripper. "Tilted workpiece": A tilted workpiece can be in the correct position when removed, but have an orientation that prevents access by the gripper. This can prevent the removal of the workpiece, thus lengthening the sorting of the workpieces.
[0021] "Contaminated workpiece support": The retention of production residues on and / or in the workpiece support prevents the proper positioning of further workpieces to be removed, which also complicates sorting after the sorting process. This is particularly problematic when using workpiece supports with so-called web supports. Furthermore, a contaminated workpiece support can occur due to wear and / or contamination, which can complicate the proper positioning of the workpieces and thus complicate sorting.
[0022] "Jammed and / or jammed workpiece": A workpiece that is jammed and / or jammed between other workpieces and / or the workpiece support makes it difficult for the gripper to remove it. This can prolong the sorting of the workpieces.
[0023] "Welded and / or incorrectly cut workpiece": In this case, the workpiece may still be attached to another workpiece after production, in particular the scrap skeleton, in such a way that removal by the gripper is impossible. This may result in damage and / or displacement of the workpieces as well as damage to the gripper. In any case, the sorting of the workpieces is prolonged.
[0024] "Incorrect occupancy of the workpiece support": Incorrect occupancy of the workpiece support by the workpieces prevents the removal of the workpieces according to the predetermined sorting sequence. This can significantly extend or even prevent sorting. According to the invention, when a process disturbance is identified, the measure for adapting the sorting process is automatically initiated. In other words, the process disturbance is responded to automatically. The measure for adapting the sorting process can consist of bypassing the process disturbance, for example, by skipping the removal of a missing part, or in rectifying the process disturbance, for example, by cleaning the contaminated workpiece support. Example measures can also consist of changing the removal sequence of the workpieces, attempting removal with changed access settings, and / or issuing an instruction.
[0025] Preferably, an instruction relates to changing the layout of the workpiece support, remaking missing or incorrectly cut workpieces, and / or intervention by a specialist. This can counteract a process disruption whose cause lies outside the scope of intervention by the sorting process, thus preventing further process disruptions.
[0026] In summary, the method according to the invention is designed to monitor the removal area and identify existing and / or emerging process disturbances. Upon identification of the process disturbance, the sorting process automatically reacts. This allows for increased process reliability, process speed, and the degree of automation of the sorting process.
[0027] In a preferred embodiment of the sorting method, it is provided that the creation of the actual image and the identification of the process disturbance takes place, in particular immediately, before and / or after the sorting of one of the workpieces.
[0028] By creating the actual map and identifying the process disturbance, especially immediately before a workpiece is removed, a suddenly occurring process disturbance can be identified. This can further increase process reliability. By creating the actual map and identifying the process disturbance, especially immediately after a workpiece has been removed, a process disturbance that occurs after removal can be identified. Particularly advantageously, the measure can then be initiated while the workpiece is being set down. This can further increase process speed.
[0029] By creating a map of the actual situation and identifying the process disturbance, especially immediately before and after removal, proper removal of the workpiece can be monitored. Process reliability can be further increased by adapting the gripper's removal strategy.
[0030] In a preferred embodiment of the sorting process, the actual image is created photographically. A camera is preferably used to create the actual image. The actual photographic image is preferably converted into an image format that can be analyzed using image analysis. This allows reliable methods for graphic image analysis to be applied cost-effectively for the sorting process.
[0031] Furthermore, it can be provided that the actual image is created using sensors. Preferably, a laser scanner is used in this case. Creating the actual image using sensors has particular advantages for sampling areas where a continuous recording of the entire sampling area is prevented by optical blockages, for example in the form of dust and / or objects. A sensory actual image can be created, for example, using a surface scan. The surface image is then preferably converted into an image format, allowing an analysis of the actual image using graphic image evaluation.
[0032] Furthermore, an embodiment of the sorting method is preferred in which at least two actual images are created, and the process disturbance is identified by analyzing the two actual images. Preferably, the actual images are created using two different imaging devices, for example, two cameras, and / or from different directions. This allows the process disturbance to be identified redundantly by analyzing both actual images.
[0033] In a preferred embodiment of the sorting method, a spatial position and / or spatial orientation of the workpieces is determined and evaluated from the actual image. In other words, the individual workpieces are identified in the actual image, and each workpiece is subsequently assigned a position and / or spatial orientation. This allows the sorting process to be adapted so that the workpieces can be removed particularly quickly, since the gripper can approach the workpieces particularly quickly and reliably.
[0034] The position of the workpiece can be understood, for example, as the geometric center of the workpiece. Preferably, an ideal access position for the gripper can be determined from the position of the workpiece. This makes it particularly easy for the gripper to move to the position of the workpiece.
[0035] The orientation of the workpiece can be understood as an alignment with respect to a coordinate system of the removal area. For example, the workpiece can have an inclined and / or rotated orientation relative to the removal area. In the case of an inclined and / or rotated orientation, the sorting process can be adapted, for example, by having the gripper adapt to the orientation of the workpiece to enable removal.
[0036] In a preferred development of the sorting method, the process disturbance is identified by a distance determined by comparing the spatial positions of two workpieces in the actual image. In other words, the positions of the two workpieces are first determined, followed by the distance between the two workpieces. This allows, for example, a process disturbance caused by overlapping of the two workpieces to be identified. Preferably, the distance is determined from the actual image by taking the contours of the workpieces into account. This allows the process disturbance to be identified more reliably.
[0037] Furthermore, a further development of the sorting method is preferred in which a target image is provided which represents the expected state of the removal area and the process disturbance is identified from a predetermined deviation of the spatial position of the workpieces between the actual image and the target image and / or from a predetermined deviation of the spatial orientation of the workpieces between the actual image and the target image.
[0038] An "expected state" can, for example, include an expected position and / or orientation of the workpieces and / or an expected state of the removal area. In other words, the target image has expected characteristics of the removal area. The target image can, for example, be provided in the form of a production plan of the workpieces of the flatbed machine tool and / or a reference image in which the expected characteristics were determined. In the latter case, the actual image of a first comparison can be used as a reference image for a subsequent comparison. This is preferably stored automatically.
[0039] In a preferred embodiment of the sorting method, the process disturbance is identified by comparing a state of an absorbed removal area determined from the actual image with a proper state of the absorbed removal area determined from the target image.
[0040] In a preferred embodiment of the sorting method, the sorting sequence is adjusted by the gripper by suspending the sorting process, changing the removal sequence of the workpieces, issuing a warning, informing an operator, cleaning the removal area, and / or changing a removal strategy. In other words, the process disruption is either eliminated or bypassed, allowing automatic sorting to continue. This increases process reliability and speed, and reduces interventions by a specialist.
[0041] The underlying problem is further solved by a sorting device for automatically removing workpieces from a removal area of a flatbed machine tool and depositing the workpieces in a storage area after a sorting process. The sorting device is preferably configured to carry out the previously described sorting method.
[0042] The sorting device has a controller for controlling a gripper of the sorting device, wherein the gripper is designed to grip the workpieces.
[0043] Furthermore, the sorting device has at least one imaging means which is designed to create an actual image of the removal area.
[0044] Furthermore, the sorting device has an evaluation unit which is configured to identify a process disturbance by analyzing the actual image of the removal area.
[0045] According to the invention, the control of the sorting device is designed to automatically initiate a measure to adapt the sorting process when a process disturbance is identified.
[0046] In a preferred embodiment of the sorting device, the at least one imaging means is designed as a camera, a laser scanner, and / or a light-section sensor. This allows a rapid and comprehensive image of the removal area to be created, with evaluation being carried out in a process-efficient manner using an image evaluation unit.
[0047] Further preferred is an embodiment of the sorting device in which the at least one imaging means is positioned stationary above the removal area. Such an arrangement enables the complete imaging of the removal area from a fixed position at a fixed angle. This facilitates the analysis of the actual image by the evaluation unit.
[0048] Furthermore, an embodiment of the sorting device is preferred in which the sorting device has at least two imaging means, wherein at least one of the imaging means is attached to the gripper. A further imaging means enables redundant imaging of the removal area, in particular from a further imaging direction. This allows, for example, if one imaging means is partially blocked, an analysis to be performed using the actual image of the other imaging means.
[0049] In a further aspect of the invention, it can be provided that the at least one imaging means attached to the gripper is configured to create an actual image of the storage area. Furthermore, it can be provided that a process disturbance in the storage area, for example, an overturned storage stack, is identified by analyzing the actual image of the storage area. For identification purposes, it can be provided that the actual image of the storage area is compared with a provided target image of the storage area. This can further increase process reliability.
[0050] Further features and advantages of the invention will become apparent from the description, the claims, and the drawings. According to the invention, the above-mentioned and further-described features can be used individually or in combination in any convenient way. The embodiments shown and described are not to be understood as an exhaustive list, but rather as examples for describing the invention. Detailed Description of the Invention and Drawings
[0051] Fig. 1 shows an arrangement with a flatbed machine tool and a sorting device according to the invention in a perspective view.
[0052] Fig. 2 shows the method according to the invention in a schematic flow diagram.
[0053] Fig. 3 shows an actual image of a removal area with workpieces positioned on a workpiece support with a shifted workpiece in a schematic representation.
[0054] Fig. 4 shows a target image of the removal area from Fig. 2 with an expected position of the workpieces.
[0055] Fig. 5 shows a first removal area after initiating a first measure for adapting a sorting process in a sectional schematic representation.
[0056] Fig. 6 shows a second removal area after initiating a second measure for adapting the sorting process in a sectional schematic view.
[0057] Fig. 7 shows a third removal area after initiating a third measure for adapting the sorting process in a sectional schematic representation.
[0058] Fig. 1 shows an arrangement 10 with a flatbed machine tool 12 in the form of a laser cutting machine, a sorting device 14, a removal area 16, and a storage area 18. The exemplary sorting device 14 has a gripper 20, which, by being arranged on a boom 22, can be moved via a rail guide 24 along an axis 26 between the removal area 16 and the storage area 18. Furthermore, the gripper 20 can be moved translationally and rotationally with respect to the boom 22.
[0059] A workpiece support 28 is positioned in the removal area 16. The workpiece support 24 has a web support 30. Several workpieces 32, which were previously manufactured in the flatbed machine tool 12, are positioned on the workpiece support 28 (for reasons of clarity, only one workpiece 32 is provided with a reference symbol). An imaging means 34 of the sorting device 14, designed as a camera, is mounted above the removal area 16. The imaging means 34 is directed vertically downward toward the removal area 16 and is configured to image the entire area.
[0060] A storage pallet 36 is positioned in the storage area 18, which serves to store and transport the workpieces 32.
[0061] To sort the workpieces 32, the gripper 20 is moved according to a sorting sequence stored in a controller 37 of the sorting device 14 until the workpieces 32 have been removed from the removal area 16 and deposited in the deposit area 18. The gripper 20 moves, for example, along the axis 26 across the removal area 16 and is deflected in the vertical direction up to the workpieces 32. The gripper 20 then continues to grip one of the workpieces 32, for example, and is subsequently moved upwards in the vertical direction. The gripper 20 is then moved along the axis 26 into the deposit area 18 and deflected there in a similar manner to deposit the picked-up workpiece 32.
[0062] Fig. 2 shows a schematic representation of a sorting method 38 according to the invention, which will be explained by way of example with reference to Figs. 3 and 4.
[0063] In a first method step "Creating the actual image" 40, an actual image 42 (see Fig. 3) of the removal area 16 is created. The actual image 42 is created, for example, by the imaging means 34 designed as a camera (see Fig. 1) and can be in the form of a two-dimensional photograph. The actual image 42 can capture the removal area 16 as a whole, as shown in Fig. 3, and depicts the workpiece support 28 with the web support 30 as well as the workpieces 32. In a subsequent method step "Analyzing the actual image" 44, the actual image 42 is analyzed or evaluated. The image areas shown in the actual image 42 are assigned to predetermined components based on their characteristics. Characteristics of the image areas can be, for example, brightness, structure, and / or shape.
[0064] For example, the removal area 16 in the actual image 42 according to Fig. 3 can be distinguished from the workpieces 32 by its surface structure. Furthermore, for example, the workpieces 32 can be distinguished from one another by a cutting edge that is set apart from the image areas of the workpieces 32.
[0065] The analysis also includes the determination of predetermined properties of the identified components, on the basis of which a process disturbance can be identified.
[0066] For example, a predetermined property of the determined components can be a minimum distance from another component. According to the actual image 42, all workpieces 32, with the exception of a defective part 46 and a residual skeleton 48, have a minimum distance from the other workpieces 32. Preferably, based on the properties of the remaining workpieces 32, it is determined that the residual skeleton 48 is correctly positioned and only the defective part 46 is misplaced relative to the workpieces 32.
[0067] In a process step "Identifying the process disturbance" 50, a deviation of the properties of the components determined in the actual image 42 from predetermined properties can be identified as a process disturbance. For example, a process disturbance can be identified if the defective part 46 does not have the required minimum distance from the residual skeleton 48.
[0068] If a process disturbance is identified, a measure for adapting the sorting process is automatically initiated in a process step "Automatic initiation of a measure" 52. For this purpose, at least one measure to be initiated is stored in the controller 37 of the sorting device 14 for each process disturbance that occurs.
[0069] For example, the sorting process for the defective part 46 can be adapted by changing the removal access by the gripper 20. In this case, for example, it can be provided that the defective part 46 is first rotated by the gripper 20 and then removed. Alternatively or additionally, it can be provided that the removal of the defective part 46 takes place only after the removal of the remaining workpieces 32.
[0070] In a preferred embodiment of the sorting method 38, in the method step "Analyzing the actual image" 44, a comparison of the actual image 42 with a target image 54 (as shown in Fig. 4) can be carried out. The target image 54 preferably represents the same section of the removal area 16 as the actual image 42. The target image 54 represents the expected state of the removal area 16. By comparing the actual image 42 with the target image 54, any deviation in the actual image can be determined in a particularly simple manner by means of image analysis. The identification of a process disturbance can thus be carried out particularly quickly and reliably.
[0071] Fig. 5 shows the removal area 16 after initiating a measure to adapt the sorting process.
[0072] According to the exemplary illustration in Fig. 5, the removal area 16 has the defective part 46, which rests on one of the workpieces 32 on the one hand and on the web support 30 of the workpiece support 28 on the other. The defective part 46 has a position changed by a translational deflection 56 and an orientation changed by an angle 58, so that the gripper 20 may not be able to grip the defective part 46 when proceeding according to the originally intended sorting sequence. In the process step "Analyzing an actual image" 44 (see Fig. 2), the defective part 46 was determined. In the process step "Identifying a process disturbance" 50 (see Fig. 2), the process disturbance "Tilted workpiece" was identified because the defective part 46 has a position and orientation that deviates from its expected position and orientation.
[0073] In order to enable removal by the gripper 20, the sorting process was automatically changed by adjusting the position and orientation of the gripper to the position and orientation of the defective part 46.
[0074] Fig. 6 shows the removal area 16 after initiating a further measure to adapt the sorting process.
[0075] According to the exemplary illustration in Fig. 6, the removal area 16 has the defective part 46, which is arranged on the one hand between the workpiece 32 and the web support 30 and on the other hand rests on the web support 30. In other words, the defective part 46 has slipped under the workpiece 32 by the deflection 56. Removing the defective part 46 by the gripper 20 can lead to a significant displacement of the workpiece 32, as a result of which the workpiece 32 could be damaged or tilt.
[0076] In the process step "Analyzing an actual image" 44 (see Fig. 2), the defective part 46 was identified. In the process step "Identifying a process disturbance" 50 (see Fig. 2), the process disturbance "Jammed and / or jammed workpiece" was identified.
[0077] To prevent displacement or damage to the workpiece 32 or other workpieces 32 during removal of the defective part 46 by the gripper 20, the sorting process was automatically modified, firstly, by the use of a retaining means 60 and, secondly, by adapting a removal strategy of the gripper 20. While the retaining means 60 applies a retaining force to the workpiece 32 in the vertical direction to prevent it from being lifted and shifted, the gripper 20, after gripping the defective part 46, first performs a return movement counter to the deflection 56. This allows the defective part 46 to be unthreaded without shifting the workpieces 32.
[0078] Fig. 7 shows the removal area 16 in an absorbed state without workpieces 32 (see Figs. 1 to 6) after initiating a third measure for adapting the sorting process.
[0079] According to the exemplary illustration in Fig. 7, the removal area 16 has a production residue 62, in particular a slug, and a contamination 64, in particular slag, which are arranged in the web support 30 and prevent a positioning of workpieces 32 or already negatively influence the production of the workpieces 32 in the flatbed machine tool 12 (see Fig. 1).
[0080] In the process step "Analyzing an actual image" 44 (see Fig. 2), the production residue 62 and the contamination 64 were determined. In the process step "Identifying a process disturbance" 50 (see Fig. 2), for example, the process disturbance "Contaminated workpiece support" was identified.
[0081] To enable proper production and positioning of the workpieces 32 on the workpiece support 28 and thus rapid sorting of the workpieces 32, the sorting process is automatically modified by the use of a cleaning agent 66 in the form of a brush. While the gripper 20 remains in a rest position, the cleaning agent 66 is inserted into the web support 30 and pulled through it in a horizontal direction. This allows both the production residue 62 and the contamination 64 to be effectively removed.
[0082] 10 arrangement;
[0083] 12 flatbed machine tool;
[0084] 14 sorting device;
[0085] 16 withdrawal area;
[0086] 18 storage area;
[0087] 20 grippers of the sorting device 14;
[0088] 22 boom of the sorting device 14;
[0089] 24 Rail guide of the sorting device 14;
[0090] 26 axis of the rail guide 24;
[0091] 28 Workpiece support;
[0092] 30 web support of the workpiece support 28;
[0093] 32 workpiece;
[0094] 34 imaging means of the sorting device 14;
[0095] 36 storage pallet;
[0096] 37 Control of the sorting device 14;
[0097] 38 sorting methods;
[0098] 40 Process step “Creating an actual image”;
[0099] 42 Actual figure;
[0100] 44 Process step “Analyzing the actual mapping”;
[0101] 46 faulty part;
[0102] 48 residual skeletons;
[0103] 50 Process step “Identifying a process disturbance”;
[0104] 52 Procedural step “Automatic initiation of a measure”;
[0105] 54 Target image;
[0106] 56 deflection;
[0107] 58 angles;
[0108] 60 restraint devices;
[0109] 62 production residues;
[0110] 64 contamination;
[0111] 66 cleaning agents.
Claims
Claims Sorting method (38) for automatically sorting workpieces (32) arranged in a removal area (16) of a flatbed machine tool (12), in particular a laser cutting machine or a punching machine, into a storage area (18) after a sorting process; characterized by the steps: Creating (40) at least one as-is image (42) that depicts the actual state of the extraction area (16); Analyzing (44) the actual state image (42) to identify (50) process disturbances, wherein, upon identification of a process disturbance, a measure to adjust the sorting sequence is automatically initiated. Sorting method (38) according to claim 1, wherein the creation (40) of the actual state image (42) and the identification (50) of the process disturbance are performed before and / or after the sorting of one of the workpieces (32). Sorting method (38) according to claim 1 or 2, wherein the actual state image (42) is created photographically, in particular by means of a camera, and / or sensorially, in particular by means of a laser scanner. Sorting method (38) according to any one of the preceding claims, wherein at least two actual state images (42) are created, and the process disturbance is identified by analyzing (44) the two actual state images (42).Sorting method (38) according to any one of the preceding claims, wherein a spatial position and / or a spatial orientation of the workpieces is determined and evaluated from the actual image (42). Sorting method (38) according to claim 5, wherein the process disturbance is identified by a distance determined by comparing the spatial positions of two workpieces (32) in the actual image (42). Sorting method (38) according to claim 5 or 6, wherein a target image (54) is provided which represents the expected state of the... The sorting method (38) according to one of the preceding claims, wherein a target image (50) is provided that represents the expected state of the sorting area (16); and wherein the process disturbance is identified by comparing a state of a sorted sorting area (16) determined from the actual image (42) and the target image (50) with a proper state of the sorted sorting area (16) determined from the target image (50).Sorting method (38) according to one of the preceding claims, wherein the sorting process is adapted by suspending the sorting process, changing a removal sequence of the workpieces (32), issuing a warning, informing an operator, cleaning the removal area (16) and / or changing an access by a gripper (20).Sorting device (14) for automatically removing workpieces (32) from a removal area (16) of a flatbed machine tool (12) and depositing the workpieces (32) in a storage area (18) after a sorting process, in particular configured for carrying out the sorting method (38) according to one of the preceding claims, comprising a control (37) for controlling a gripper (20) of the sorting device (14), wherein the gripper (20) is configured for gripping the workpieces (32); at least one imaging means (34) configured for creating an actual image (42) of the removal area (16); an evaluation unit for identifying (50) a process disturbance by analyzing (44) the actual image (42) of the removal area (16);. wherein the control (37) is configured to automatically initiate (52) a measure to adjust the sorting process upon identification of a process disturbance. Sorting device (14) according to claim 10, wherein the at least one imaging means (34) is configured as a camera, a laser scanner and / or a light section sensor. Sorting device (14) according to claim 10 or 11, wherein the at least one imaging means (34) is positioned stationary above the removal area (16). Sorting device (14) according to any one of claims 10 to 12, wherein the sorting device (14) has at least two imaging means (34), wherein at least one of the imaging means (34) is attached to the gripper (20).