Patent Application
20240027991
The present invention relates to a computer implemented method for planning a manufacturing process of a final element from an element, using laser means, such as planning a sequence of bending and forming processes to a metal element so as to manufacture a final metal element, using said laser means.
Processing of elements, such as sheet metal, into a final element is currently done by a performing a plurality of processes, such as laser cutting, grinding, bending, drilling, milling, polishing, punching, hydroforming, engraving, marking, surface treating, incremental forming and forming the metal element, so as to create a final element which has undergone one or more of the above mentioned processes. When an element is subdued to one or more processes, the element is to be moved between a plurality of machines, such as a laser cutter, a milling machine and a bending machine. Having more machines in a shop requires more costs to maintain said machines and more operators, in order to have the required skills to set up and operate said machines, which further adds to costs and time consumption, to create a final element. Implementing or translating some or all of the above processes into a single laser device is a challenge, as this would require to calculate/foresee and hence create a complex plan, as to how an element is to be processed, in order to achieve a final element, wherein the sequence of processes does not inflict a process impediment, throughout said sequence of processes.
When attempting to replace all of the above processes with laser processes, one challenge is to figure out which processes should be done first or last in order to achieve the desired end result. A sequence of processes is to be made and the more complex the final element is, the more complex the sequencing method will become.
Hence, an improved method for planning said sequences would be advantageous, and in particular a more efficient and/or reliable computer implemented method would be advantageous.
It is a further object of the present invention to provide an alternative to the prior art.
In particular, it may be seen as an object of the present invention to provide a computer implemented planning method that solves the above mentioned problems of the prior art with planning how to sequence the manufacturing of a final element from an element, such as planning a sequence of bending and forming processes to a metal element so as to manufacture a final metal element, using laser means.
In a first aspect, the invention relates to a computer-implemented method for planning a laser processing of one or more elements into one or more final elements, the method comprising:
In the context of the present invention, laser processing is to be understood as an operation or treatment performed to the element, such as a metal element, so as to manufacture or create a final element different from a non-processed element, e.g. surface treating, colour treatment, drilling, case-hardening, shaping, bending, forming, cutting or welding said metal element. The laser processing is to be performed by a laser device or other laser means.
In the context of the present invention, a laser device or laser means is to be understood as an apparatus configured for generating a beam of coherent electromagnetic radiation usually in the ultraviolet, visible, or infrared regions of the spectrum, such as, but not limited to a fiber laser, a CO2 laser, pulsed-rod laser, a solid-state laser, a disc laser, a diode laser or a UV laser. A laser comprises an energy source which is directed from the laser to a point of interest and in the context of the present invention, a vector is to be understood as the direction from which the laser origins, to a point at which the laser interacts with the metal element, which defines a directed line segment between the laser and the metal element.
In the context of the present invention, shaping is to be understood as applying energy to a surface of a metal element so as to create or form e.g. a double curved, a convex or concave shape in said metal element, through heat expansion/contraction of said metal element. As an example, by applying energy to said element in a continuously calculated pattern, the invention can create a desired indentation or depression into a surface of said metal element. In another example, the invention can create a cone shape into or out from said metal element, by applying energy to a surface of said metal element, so as to manipulate certain sections of the surface of said metal element, through energy applied to certain points of said surface of said metal element.
In the context of the present invention, cutting is to be understood as cutting into a surface so as to create a surface groove or cutting through a surface and creating a through-going groove or cutting a metal element into a plurality of metal elements. As an example, laser ablation can be used to create a hole in a surface, which resembles the hole of a manual drilling process.
In the context of the present invention, bending is to be understood as bending a section of the metal element at an angle, relative to an adjacent section of said metal element, such as by bending a sheet metal into a 90 degrees angle.
In the context of the present invention, the element is to be understood as a metal element, a polymer element, a fiber element, a ceramic element or an alloy element. The final element may further be manufactured from two or more elements, such as a metal element and a polymer element. Furthermore, more final elements may be manufactured from one or more elements, according to the invention. Further, a metal element is to be understood as any element comprising metal, such as, but not limited to, iron, lead, gold, aluminum, platinum, uranium, zinc, lithium, sodium, tin, silver, copper, brass, titanium, magnesium, steel, a galvanized metal or any metal alloy. As an example, a metal element could be a block or plate of copper or a sheet metal, such as a steel sheet metal element.
In an embodiment of the present invention, the element to be processed is heavy enough, that said element does not move during processing, in which, fixation structures may not be needed in order to keep the base structure still from movement.
In the context of the present invention, an element model is to be understood as a data file comprising e.g. geometric data, specifications, such as material information, surface colour, heat treatment and other relevant data regarding the element which is to be processed.
In the context of the present invention, the final model is to be understood as a list of instructions or file containing technical drawings, such as a CAD file of the final element, to be interpreted by a computer. In another embodiment of the invention, the final model may be provided by scanning and/or measuring an existing prototype/final element, which is to be manufactured from a provided element, using the method according to the first aspect of the invention.
In an embodiment of the invention, the following steps may be applied, to provide an element model and/or a final element model:
Import and analyse CAD data for an element or final element:
Detect and convert manufacturing information:
If a final element is designed for laser processing, the conversion step can be skipped.
Project final model onto element model:
In the context of the present invention, a graph or undirected graph is to be understood as a structure consisting of vertices which are connected by edges. The graph is able to represent the geometrical structure of a part or structure.
In the context of the present invention, a vertex or more vertices are to be understood as a structure or base structure.
In the context of the present invention, projecting or projection is to be understood as applying a final model onto a model of an element, which is to be processed into a final element from an element. As an example, an unfolded 2-dimensional model of a 3-dimensional square box is projected onto a flat, or substantially flat metal plate, so as to identify which process steps to apply, in order to cut and bend the metal plate into said square box.
In the context of the present invention, a flat element is to be understood as an element having the major surfaces essentially parallel and distinctly greater than the minor surfaces.
In the context of the present invention, a base structure is to be understood as a central or substantially central part of the element model, which is connected to one or more other structures of the element, which are part of the final model, e.g. when creating a square box from a flat, or substantially flat metal plate the base structure may be the bottom portion and the processing structures may be the sides and top portion or lid of said square box. In most or all cases, the base structure is connected to the element during the processing of the final element from sections of the element, and wherein e.g. a processing structure can be cut free from the element, still connected to the base element, so that any stabilizing connection to said processing structures goes through the base structure. In some cases, the base structure is intermittently cut free from the element, generating a plurality of fixation structures along the cut edges of the base structures, while one or more processing structures are being processed. In an embodiment of the invention, the fixation structures may be edges or protrusions along the bottom portion of the base structure, which has not been cut or separated from the element, so as to fixate the base structure while bending or otherwise processing the base structure or processing structures to manufacture the final element.
In the context of the present invention, connections are be understood as non-cut parts of the element, such as an edge between the base structure and a processing structure and wherein said edge may either be cut or bend at a later stage of the process. Connections are further to be understood as any sections which may supply mechanical links between the element and/or the base plate and/or the processing structures and/or the fixation structures. Furthermore, edges may represent connections between faces or joints to itself if it represents internal structures. Edges can be cuts, welds and bends, such as single curved bends.
In the context of the present invention, non-processed is to be understood as any surface or section of the element which are not laser processed during the manufacturing of the final element from the element. As an example, when supplying a metal plate with a surface area larger than the surface area of the final model, the non-processed sections of the metal element are the residual metal plate, after the final element has been manufactured.
In the context of the present invention, laser process specifications are to be understood as quality requirements for performing any laser processes to complete the process steps.
Laser process specifications (quality requirements) are either read from an input geometry, such as a data file or requested from a database containing the necessary information. Laser process specifications are generated based on quality requirements for each of the laser processes. A lookup table may store the laser process specifications but one or more specifications may be subject to continuous or intermittent measurements during a laser process. Quality requirements for the laser processes may be one or more, but not limited to the following examples:
In the context of the present invention, a set of instructions is to be understood as a sequence or order of connected series of processes and laser process specifications for each of said processes. As an example, a set of instructions may comprise a laser cutting process, a laser bending process and a laser welding process in that order, and laser process specifications for each of said process.
The invention is particularly, but not exclusively, advantageous for obtaining a computer-implemented method for calculating how to process at least one element, such as a metal element into one or more final elements using a single laser device and thus, by implementing the invention in an existing laser device, replacing a plurality of processing machines, such as, but not limited to, a bending or forming machine, a milling machine, a drilling machine, a grinding machine and a cutting machine. Using a single machine for performing all of the abovementioned processes saves time, is more efficient and increases the accuracy of the performed processes. It is to be understood that two or more final elements may be manufactured from one or more metal elements or one or more metal elements and elements from a material different from metal. Further, it is to be understood that by calculating the method for processing an element, such as a metal plate, into a complex 3-dimensional final element, without shadowing the laser device from completing the process. As an example, when bending several sections of a base element, the order of process steps should be organized, so that no previous process step is completed if a subsequent process step is prevented from said previous process step. In this context, the present invention is particularly advantageous for proposing an order of process steps which can be completed.
In another advantageous embodiment of the invention, the method may comprise calculating/proposing to an operator, to cut one or more processing windows in a section of the non-completed element, so as to enable the laser device to reach into a section of said non-completed element, which would otherwise be shadowed/screened from further processing. In the context of the present invention, the term for creating a structure which blocks the laser device from having access to process other structures, is referenced as shadowing and is to be understood as screening, blocking, obscuring or otherwise preventing the processing means from reaching the point of processing.
The surface treatment of a final element is to be understood as a thermal heating process of either an outer surface layer or deeper into a layer of the material, from which the final element is processed. This embodiment is advantageous for creating a wear-resistant or weather-resistant surface of a final element, after a shaping, bending, forming or welding process by surface processing the element, such as by surface processing a metal element.
Furthermore, the invention is advantageous for forming, cutting and bending at least one metal element, so as to bend a section of the metal element towards a second section of the metal element and create a final element, e.g. a substantially square box, a rounded, donut shaped element, a rotor blade. The invention is particularly advantageous for creating interlocked elements, such as by cutting a protruding element in a first section of the metal element, and cutting a corresponding hole in a second section of the metal element and bending the first or second section in order for the protruding element to abut to or be bent through the hole. For further interlocking the protruding element with the hole, the protruding element, when inserted through the hole, can be bent or welded on a backside of the second section of the metal element.
In an advantageous embodiment of the invention, the method further comprises providing measuring means for measuring one or more of the base structures, the processing structures or the fixation structures during the processing of the element into the final element, and generating at least a second set of instructions from the measurements provided by the measuring means.
In the context of the present invention, measuring means is to be understood as means for measuring one or more geometries, densities and features of the metal element, e.g. a line scanner, a 3D scanner or 3D measuring device, an ultrasound device, an X-ray device, time of flight, a scattered light/structured light sensor, a 2D scanner, 1D scanner/point sensor, a CCD sensor system or a tactile measuring system. In other embodiments of the invention, the measuring means may further comprise other sensors, such as a temperature sensor for supplying thermal data from a section or surface of the element being processed.
This embodiment of the invention is particularly advantageous for supplying continuous or intermittent measurement data regarding the current laser process performed to a section or structure of the element to be processed.
In another advantageous embodiment of the invention, wherein two or more base structures are identified, the method further comprises:
In yet another advantageous embodiment of the invention, the set of rules for selecting a primary base structure further comprises one or more of:
Examples of how to select a primary base structure from one or more viable base structures are listed below:
Locate all feasible primary base structures of the element. The localisation of the primary base structure can be done by the following steps:
Eliminate unfeasible base structures according to e.g. laser process specifications and geometrical constraints.
Examples of constraints are:
Among the feasible primary base structures, select one preferred primary base structure based on a set of optimisation rules.
Examples of optimisation rules are:
In the context of the present invention, spanning is to be understood as the area covered between the outer corners but where e.g. cut-outs clears away large areas.
In some cases, e.g. if all process structures on the rim of the primary base structure are bend according to each other, the criteria for selecting the primary base structure is different and the fixation structures proposed in planning steps can be different by using tensioning structures. Modify the planned processing steps according to the selected primary base structure.
When a primary base structure is selected, the following rules may be applied in order to plan the subsequent processing steps:
Modify cuts on the rim of the fixation plate:
Define the order of the processing steps to optimise:
In the context of the present invention, intertask is to be understood as the step between two or more subsequent process steps and wherein said two or more processing steps may be rearranged in order to reduce risk of shadowing of a subsequent laser process step or in order to achieve time optimisation.
Identification of proceeding constraints:
Analyse the process step dependencies that specify disjunctive proceeding constraints and allowed time windows.
Examples of constraints are:
Identification of process feasibility constraints:
Check the geometry for processing feasibility.
Constraint are as follows:
Identification of accessibility constraints:
Check the geometry for accessibility for the processing tool and the measurement tool.
Constraints are:
Solve the scheduling problem:
Apply existing optimisation or heuristics algorithm to solve the problem.
Place fixation structures and include it in the processing steps:
Place fixations structures to keep at least the base structure and or other structures stable during processing and determine when every fixation structure needs to be cut free from the element. Additionally, specify the degrees of freedom, stretch length, rigidity, torsional and tensional properties and other suitable requirements to the fixation structure.
Generate set of instructions and CAD data:
Generate set of instructions and CAD data for each processing step and export the information. The CAD data may be in a form of STL or other kind of a meshed surface or such as an .amf, .stp, .iges, .obj or .dwg file.
In the context of the present invention, scheduling is to be understood as the sequence of processes to be performed in order to process the element into the final element.
In an embodiment of the invention wherein the final model of the final element is a 3-dimensional structure, the method further comprises:
In a preferred embodiment of the invention, the laser processing further comprising a laser welding process and the method further comprises:
This embodiment is particularly advantageous for joining one or more structures of the final element to each other.
In another preferred embodiment of the invention, the method further comprises:
This embodiment of the invention is advantageous for fast and reliable conversion of existing processes, so as to ensure a finished product which correspond to or is superior to a product manufactured from present processing methods.
In another embodiment of the invention, the method further comprises:
In an advantageous embodiment of the invention, the method further comprises:
This embodiment of the invention is advantageous for continuous process control, ensuring that a material, such as a metal is kept within temperature tolerances advantageous for obtaining the desired characteristics of the material of the final element.
In another preferred embodiment of the invention further comprising at least a second element and in which the first element and the second element is to be processed into the final element, the method further comprises:
This embodiment of the invention is particularly advantageous for manufacturing a complex final element comprising two or more materials, such as a metal shape lined with a polymer.
In another advantageous embodiment of the invention, the method further comprises:
This embodiment is particularly advantageous for creating complex final elements, which otherwise would provide shadowing of one or more sections of the element relative to a vector of the laser means. By adjusting the element with the automatic positioning means, the laser means has better access to a plurality of section of said element. As an example, the automatic positioning means may be a robotic arm with a gripping device, for gripping the element.
In yet another embodiment of the invention wherein the method further comprises a final model of a final element, wherein one or more structures of the final model are interlocked, the method further comprises:
This embodiment of the invention is advantageous for planning and designing interlocking sections of the metal element, so as to improve the stability and rigidity of the final model.
In another embodiment of the invention, the at least first set of instructions is configured, to be provided to an associated laser processing device, so as to enable said associated laser processing device to process the one or more elements into the one or more final elements from the one or more models of the one or more elements and the final model of the final element, by executing said at least first set of instructions.
This embodiment is advantageous for providing the invention to an array of existing laser processing devices, such as for retrofitting a laser device with the method according to the first aspect of the invention.
In another preferred embodiment of the invention, the method further comprises providing a surface analysis, said surface analysis comprising a backscatter analysis of the one or more surfaces of the element. The surface analysis may be performed prior to the processing of the element or during, either on-line or intermittently.
In the context of the present invention, backscatter is to be understood as any deviation from expected light being reflected back in the direction from which it came, such as an expected reflection from a metal surface and wherein said backscatter may be converted into a map of the surface, said map comprising reflective information relating to all relevant areas of said surface. In other embodiments, the surface may comprise one or more of ceramics, paint or coatings, natural materials, such as wood or paper.
In an embodiment, a laser scanner may be used to measure the backscatter intensity from the laser line. As colours are a representation of the light, that is reflected from the surface in a given wavelength. The reflected wavelengths may be used to obtain an indication of the colour of the scanned surface. However, in this case, the purpose is not to obtain the colour of the surface, but to locally estimate the amount of absorbed and reflected light from the surface. The result can be represented as an image or map of the scanned surface, where the greyscale pixel intensities in an image corresponds to the amount of absorbed and reflected light. The shinier the surface, the more light is reflected and the brighter the surface will appear in the image.
When analyzing the surface, the wavelength of the laser light, used for scanning, should be close to the same wavelength as the laser used for processing, due to some surfaces reflecting different wavelengths of light. The same applies for the angle at which the laser is projected and subsequently captured on the surface, as this will also influence the result.
This embodiment of the invention, is particularly advantageous for analyzing the surfaces of the element, so as to correct or adjust for any surface defects or any contaminations, so as to ensure that the energy from the laser device, intended for processing said (metal element) is not scattered or reflected from the surface, and hence create instructions and/or process steps which correct for said surface defects or contaminations.
In the context of the present invention, defects or surface defects is to be understood as, but not limited to dents, scratches, protrusions, notches, cracks, cuts, wear, corrosion, etching, tarnish, fading, peel off or flake off and crevices or other not desired damages to the surface.
In the context of the present invention, contaminations is to be understood as, but not limited to oil, grease, hairs, dust, dirt, extraction, spillage, soot, moisture, process remains or other polluting particles present on a surface or impurities within said surface.
In a further embodiment, the surface analysis can be combined with a geometrical analysis of the element, such as a 2-D or 3-D geometrical analysis.
In yet another embodiment, the surface analysis may be used to preprocess any surfaces which may have defects or contamination.
The measuring means and the surface analysis means may be a single device, configured to provide geometrical data and surface data relating to the metal element and providing said data for processing of the element by using the laser supplied from the laser means intended for processing of the element, wherein the surface analysis is performed by using low power level settings on said laser means and a sensor for measuring the reflected backscatter
In a second aspect, the present invention relates to a computer program product comprising software code adapted to control a laser processing device, when executed on a data processing system, to process one or more elements into one or more final elements from one or more models of the one or more elements and one or more final models of the one or more final elements, by executing at least a first set of instructions, the computer program product being adapted to perform the method according to the first aspect of the invention.
This embodiment is advantageous for providing a computer program product, which may be adapted to an existing laser processing device, so as to increase the processing features of said existing laser device.
In a third aspect, the present invention relates to a device for laser processing a metal element into a final element, said device comprising:
The fixture and/or positioning means may comprise a robotic gripper, or other suitable mechanical/electric/pneumatic fixture mechanism.
In an embodiment of the invention, the position adjustment means may further comprise a conveyor belt, the method further comprising transporting one or more elements into a processing cell for processing said element into one or more final elements, and optionally transporting the final element out from the processing cell.
This embodiment is particularly advantageous for processing a plurality of elements, which are fed through a laser cell, so as to mass-produce a type of final element, saving time and reducing cost of the final elements. In other embodiments of the invention the transport mechanism for transporting an element into the processing cell may be a set of rollers, carts, wagons or coasters, suitable for transporting elements along a predetermined path.
In a fourth aspect, the invention relates to the use of a device according to the third aspect of the invention, for processing at least a first element into one or more final elements, according to the method set forth in the first aspect of the invention.
The first, second, third and fourth aspect of the present invention may each be combined with any of the other aspects. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
The planning method according to the invention will now be described in more detail with regard to the accompanying figures. The figures show one way of implementing the present invention and is not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.
Furthermore, when creating the two fixation structures, two residual sections RS1, RS 2 are created, which are not to be used for the further manufacturing of a final element. To manufacture a final element from an element, the unfolded planar model 2′ has four bending lines B1 to B4, wherein bending line 1 B1 represents a bending edge between processing structure 1 PS1 and processing structure 2 PS2, bending line 2 B2 represents a bending edge between processing structure 3 PS3 and processing structure 4 PS4, bending line 3 B3 represents a bending edge between processing structure 1 PS1 and the base structure BS, and bending line 4 B4 represents a bending edge between processing structure 3 PS3 and the base structure BS. When all processing has been performed, the two fixation structures FS1, FS2 are cut from the base structure BS, freeing the final element from the non-processed section NPS1 of the element.
Wherein tkw is the width of the cut kerf of the beam as applied to the element at the surface and cut face options are whether or not there is access, without moving the final element during processing. It should be noted that the sequence above has not yet been optimized, so as to ensure that the correct sequence order has been obtained.
This gives the following cut sequence constraints:
The circles S/E around the perimeter indicates possible starting or ending points during the laser cutting sequences.
In an embodiment of the invention, the method corrects for said detected surface defects DEF and contaminations CONT, by adjusting the energy level for the laser device/means on said affected areas DEF, CONT, so as to attain the desired process of the element 1 in spite of said defect and/or contaminated areas DEF, CONT.
Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms “comprising” or “comprises” do not exclude other possible elements or steps. Also, the mentioning of references such as “a” or “an” etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.
| Number | Date | Country | Kind |
|---|---|---|---|
| PA 2020 70454 | Jul 2020 | DK | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DK2021/050223 | 7/2/2021 | WO |
