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DE-102025142075-A1 - Method for dismantling a stack composed of partial stacks of flat products

DE102025142075A1DE 102025142075 A1DE102025142075 A1DE 102025142075A1DE-102025142075-A1

Abstract

A method according to the invention for dismantling a stack (1) composed of partial stacks (2, 3, 4) of flat products (10), wherein geometric data (21) of the stack (1) and/or the partial stacks (2, 3, 4) are optically detected, and wherein the partial stacks are successively lifted from the stack individually or in groups using a controlled robot arm (31) and using the geometric data (21) for the motion control of the robot arm, is characterized in that at least one partial stack is provided with at least one code (20) printed on a top, flat product (11) of the partial stack, that the code (20) is optically detected by a detection device (37), and that the geometric data (21) are stored in the code (20) and are read out for the motion control of the robot arm (31) and/or identification data (22) for the geometric data (21) are stored in the code (20). (20) are stored, read out, and the geometry data (21) stored in a digital memory (34) for the identification data (22) are retrieved for the motion control of the robot arm (31). The invention advantageously enables a stack of sub-stacks of flat products to be dismantled quickly, safely, precisely, and without errors, and the sub-stacks to be fed to further processing just as quickly, safely, precisely, and without errors. The invention is used, for example, in the feeding of folding carton gluing machines.

Inventors

  • Steffen Neeb
  • Michael Östreicher
  • Stefan Mutschall
  • Lennart Leon Heilemann

Assignees

  • HEIDELBERGER DRUCKMASCHINEN AKTIENGESELLSCHAFT

Dates

Publication Date
20260513
Application Date
20251015
Priority Date
20241112

Claims (16)

  1. Method for dismantling a stack (1) composed of partial stacks (2, 3, 4) of flat products (10), wherein geometric data (21) of the stack (1) and/or the partial stacks (2, 3, 4) are optically detected, and wherein the partial stacks (2, 3, 4) are successively lifted from the stack (1) individually or in groups using a controlled robot arm (31) and using the geometric data (21) for the motion control of the robot arm (31), characterized in that at least one partial stack (2, 3, 4) is provided with at least one code (20) printed on a top, flat product (11) of the partial stack (2, 3, 4), that the code (20) is optically detected by a detection device (37), and that the geometric data (21) are stored in the code (20) and are used for the motion control of the robot arm. (31) are read out and/or identification data (22) for the geometry data (21) are stored in the encoding (20), are read out and the geometry data (21) stored in a digital memory (34) for the identification data (22) are retrieved for the motion control of the robot arm (31).
  2. Procedure according to Claim 1 , characterized in that the upper, flat product (11) is horizontal and that when the coding (20) is detected, an actual X position (44) and an actual Y position (45) of the coding (20) are also detected.
  3. Procedure according to Claim 2 , characterized in that when the coding (20) is recorded, an actual angle (46) of the coding (20) is also recorded.
  4. Procedure according to Claim 2 or 3 , characterized in that the upper flat product (11) is horizontal and the read or retrieved geometry data (21) of the upper flat product (11) include a target X position (47) and a target Y position (48) for the upper flat product (11) and thus the associated sub-stack (2, 3, 4).
  5. Procedure according to Claim 4 , characterized in that the read or retrieved geometry data (21) of the upper flat product (11) include a target angle (49) for the upper flat product (11) and thus the associated substack (2, 3, 4).
  6. Procedure according to Claim 4 or 5 , characterized in that the actual X position (44), the actual Y position (45), the target X position (47) and the target Y position (48) are used to computationally check whether the top flat product (11) and thus the associated sub-stack (2, 3, 4) is correctly positioned.
  7. Procedure according to Claim 6 , characterized in that the actual angle (46) and the target angle (49) are used to computationally check whether the top flat product (11) and thus the associated sub-stack (2, 3, 4) is correctly aligned in the horizontal plane (43).
  8. Method according to one of the preceding claims, characterized in that a first encoding (20) of a first substack (2) is detected at a first location (2a) and, using geometry data (21) stored in the first encoding (20) or retrieved geometry data (21), it is computationally checked whether an assignment of first encoding (21) and first location (2a) is correct or incorrect taking into account a predetermined location tolerance.
  9. Method according to one of the preceding claims, characterized in that further information is stored in the encoding (21) and/or further information stored in the digital storage device (34) is retrieved for the identification data (22).
  10. Procedure according to Claim 9 , characterized in that the additional information is used to determine preset values (36) for a gripping tool (32) for gripping individual sub-stacks (2, 3, 4).
  11. Method according to one of the preceding claims, characterized in that several codings (20, 23, 25) are present per substack (2, 3, 4).
  12. Procedure according to Claim 11 , characterized in that several codes (20, 23, 25) are recorded simultaneously.
  13. Method according to one of the preceding claims, characterized in that the coding (20) is printed on the flat product (2, 3, 4) at a predetermined location.
  14. Procedure according to Claim 13 , characterized in that the coding (20) is printed on an adhesive flap (12) of an unfolded and flat folding box blank (11).
  15. A method according to one of the preceding claims, characterized in that the The encoding (20) is provided and printed as a digital QR code.
  16. Method according to one of the preceding claims, characterized in that the detection device (37) is arranged on the robot arm (31).

Description

invention The invention relates to a method having the features of the preamble of claim 1. field of technology The invention lies in the technical field of the graphic arts industry and there in particular in the area of handling (e.g. gripping, holding, lifting, moving and setting down) stacks of stacked, flexible and preferably printed and folded flat products such as printed sheets or folded sheets, preferably made of paper, cardboard, corrugated board, plastic or composite material, with a manipulator, in particular a robot with a robot arm and gripper device for the stacks; for example, during palletizing and depalletizing. State of the art In the production of printed materials, particularly cardboard packaging, it is common practice to assemble stacks of numerous sub-stacks of flat products onto (transport) pallets at one station and then disassemble or depalletize them after transport to another station. When assembling the (total) stacks, a specific assembly pattern is usually used, which defines the position and orientation of the sub-stacks at all levels of the stack. Assembly and disassembly can be done manually, but this is very strenuous and puts a strain on the back; since both tasks must also be performed very quickly, robots are increasingly being used. Technical solutions for depalletizing and dismantling stacks are already known. US201300170053A1 and the DE69305122T2 Each discloses a device for depalletizing a stack composed of partial stacks of flat products, wherein the partial stacks are lifted one after the other from the stack using a controlled robot arm and sensor-generated data for the motion control of the robot arm. DE69305122T2 This allows a sub-stack to be picked up from the stack even if the sub-stack is slightly shifted from the correct, theoretical position. The JP2019151421A This reveals a depalletizing robot that works in conjunction with sensors located next to the stack to depalletize it. US20150203304A1 It reveals something similar, but with sensors positioned above the stack. DE102022129021A1 In addition to sensors above the stack, it also uses a digital segmentation method. Sensory detection of stacks and/or sub-stacks in their geometry can be difficult, as complex geometries, e.g., due to the assembly scheme used, and large dimensions are sometimes present. During depalletizing, problems can arise when a pallet stack, assembled according to a specific assembly plan and consisting of partial stacks of flat products, is subject to disturbances during transport to a processing machine. For example, the partial stacks may shift. It can also happen that all partial stacks are misplaced on the pallet, for instance, if the pallet was not positioned correctly during stacking. Conversely, the pallet may not be positioned correctly during depalletizing, resulting in misplaced partial stacks. Furthermore, an incorrect assembly plan might have been used. Such errors can lead to problems during depalletizing. Technical solutions for marking printed products are already known. DE102005037497A1 Disclosure reveals a method for individually marking printable sheets with a machine-readable, unique code, e.g., a 2D barcode. Printable sheets coded in this way can be rejected, e.g., in a converting machine, such as a folding carton gluing machine, if an error, e.g., a defect pattern, is present. The information value of the individual code can be linked to the error information, and the corresponding data can be transmitted via data line, data storage, etc., to a data processing unit of the converting machine. Manufacturers of graphic products – such as printing companies with prepress, printing, and finishing departments – constantly strive to improve, or rather increase, production speed while maintaining or even improving product quality. This is also true in the production of folding cartons, where carton blanks are produced (printed and die-cut), stacked, and then the stack is broken down into smaller stacks, which are then processed further in a folding carton gluing machine. Technical task It is therefore an object of the present invention to provide an improvement over the prior art, which in particular dere enables the rapid, safe, precise and error-free dismantling of a stack of sub-stacks of flat products and the equally rapid, safe, precise and error-free feeding of the sub-stacks to further processing. Inventive solution to the problem This problem is solved according to the invention by a method according to claim 1. A method according to the invention for dismantling a stack composed of partial stacks of flat products, wherein geometric data of the stack and/or the partial stacks are optically detected and wherein the partial stacks are lifted from the stack one after the other, individually or in groups, using a controlled robot arm and the geometric data for the motion control of the robot arm, is characterized in that at least one partial stack is provided with at lea