12 Methods for modifying the path of a cutting head of a laser cutting machine
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- MITSUBISHI ELECTRIC CORP
- Filing Date
- 2013-05-21
- Publication Date
- 2026-07-09
AI Technical Summary
Laser cutting machines face inefficiencies and potential collisions due to large or irregularly shaped cutouts that fail to fall through support structures, necessitating slow up/down movements to avoid collisions, which increase manufacturing time and costs.
The cutting head is guided along bypasses to avoid previously cut out areas by determining interior and exterior locations using rasterization or ray tracing techniques, forming a hierarchical nesting tree to optimize cutting order and minimize collisions.
This method allows efficient cutting without slow head movements, utilizing graphics processing units (GPUs) for fast processing and minimizing collision risks, thus enhancing production efficiency and reducing costs.
Abstract
Description
[Technical field]
[0001] This invention relates generally to moving a laser cutting device according to a pattern to cut sections from a sheet of material, and in particular to moving the laser cutting device along bypasses to avoid collisions between the cutting head and previously cut sections from the material. [State of the art] Laser cutting of sheet material
[0002] Cutting sections from sheet material according to a pattern is a common manufacturing process. Generally, a laser cutting head is moved in a defined plane along orthogonal axes. Laser cutting devices of this type are frequently used to cut separate sections from plastic and metal sheets of varying thicknesses. The laser cutting device is typically controlled by a computer numerical control (CNC) machine, which follows a prescribed list of instructions known as "NC code" or "G code."
[0003] Two types of laser cutting head movements are typically used. A pure displacement or lateral movement can be performed by a very rapid sideways movement in the plane of the material while the laser is continuously switched on. This type of movement is preferred.
[0004] Up / down head movements are relatively slow. This type of movement usually requires stopping the cutting head and switching the laser on and off while the head is moving up / down. Therefore, this type of movement should be avoided as much as possible to minimize manufacturing time. Thus, two basic movements are defined: fast lateral movement and slow up / down movement. Closed and nested cutouts
[0005] A part is defined by a pattern of lines, straight or curved, which is followed by the laser cutting head as specified by the code instructions. A cutout is defined by one or more connected lines, and the part is defined by a set of one or more cutouts. Often, the cutouts are nested. The lines of some cutouts are closed, allowing the cutout to be removed from the material. Open cuts, such as slits, along the edges of the pattern can also be cut. CAD / CAM and G-code
[0006] The part and set of cutouts are typically defined as a single computer-aided design (CAD) file. For example, a common CAD file format is the Drawing Change File (DXF). Such a file often contains specifications for individual parts that can be repeated using associated scales, rotations, and translations. To maximize material utilization, computer-aided nesting (CAN) is often used to automatically position the set of parts within a minimal amount of material. Once the geometry of all parts is defined, which is referred to as a "job," a computer-aided manufacturing (CAM) program can be used to generate the actual G-code instructions to execute the job. The CAM output is almost always specific to the laser cutting machine that executes the G-code instructions. Collisions
[0007] The sheet material can be arranged horizontally on a support structure. This support structure typically has vertical bars or pins spaced at intervals to allow cut sections of the material to fall through and be removed from the work area. However, large or irregularly shaped cut sections may not fall through the support structure and could potentially collide with the cutting head. This presents a problem. Such collisions can be very costly due to the complex nature of the cutting head and the repair time required, making it crucial to avoid pre-cut sections to prevent interruptions in the workflow. Upward / downward movement of the head
[0008] One solution avoids potential collisions with previously cut sections by raising the cutting head after each cut, moving it laterally to the next section to be cut, and then returning the head to the downward position. However, the upward and downward movements of the head are clearly slow compared to the lateral movements, adding considerable time and complexity to the job, thus increasing costs and reducing efficiency. Therefore, this collision avoidance method is suboptimal.
[0009] US Patent 6,609,044 defines a bounding box around each section to be cut and ensures that the cutting head does not cross the bounding box. Although this method is effective in preventing collisions without the use of slow up / down head movements, the use of a bounding box is highly inefficient for many common patterns.
[0010] US Patent 7,702,416 uses a drawing specification for motion control, for example, of a cutting machine. Elements in the drawing are ordered according to, for example, a nesting pattern or a distance from the center of the drawing specification. Code is generated to implement motion control based on the identified elements and their order. The general code can include inserted operations such as raising, lowering, and movement operations. Processing
[0011] There are two fundamental image processing techniques: rasterization and ray tracing. Both techniques typically use a frame buffer. A frame buffer is an array stored in memory. The addresses of this array correspond to the coordinates of pixels in the image being generated. Values such as intensity, color, transmittance, opacity, and the like can be assigned to these pixels. In conventional image processing, these values relate to the visual appearance of what is being processed.
[0012] Rasterization converts a 2D image-space representation of sections of a scene into a raster format, and the resulting pixel values are determined. When a graphics pipeline is used, a stream of polygons, such as triangles with vertices, edges, and faces, is converted into the pixel values in a grid.
[0013] In ray tracing, the scene is analyzed pixel by pixel by emitting rays from a viewing point. When scene features intersect, the pixel values are evaluated; for example, the color value of the feature at the intersection point becomes the value of that pixel in the field. Appearance values such as intensity, color, transmittance, opacity, and the like can then be assigned to the pixels. [Summary of the invention]
[0014] During laser cutting, large or irregularly shaped cutouts may not pass through a support structure when parts are being cut. This is a problem because the cutting head may collide with the cutouts.
[0015] The embodiments of the invention provide a solution to the aforementioned problem by moving the cutting head along bypasses in such a way as to avoid already cut sections.
[0016] Locations within a part's pattern are evaluated to determine whether they are inside or outside a cutout to be created from the pattern. The pattern is used to cut the cutout from a material using a laser cutting machine. If all locations are inside, then they are part of the cutout; otherwise, they are not, and the locations can be used to bypass the cutout after the part has been cut.
[0017] In this section, a field stored in a memory is processed in such a way that a value stored at an address in the field, which corresponds to the coordinates of the location, and which is determined by a counting process of the processing, is either odd or even.
[0018] The location is then identified as inside if the value is odd, and as outside if the value is even. The processing can result in modified forms of either rasterization or ray tracing.
[0019] One advantage is that processing can be carried out in a graphics processing unit or a processing pipeline to accelerate processing compared to conventional methods.
[0020] The laser cutting device can be guided around cutouts previously made from a material by a laser cutting machine according to a pattern, using specific locations. A hierarchical nesting tree, corresponding to a nesting sequence of all cutouts, is formed according to the check, with each node in the tree representing a cutout and a root of the tree representing a combination of the cutouts. The cutouts are then cut according to the nesting sequence, while bypassing the cutouts previously made from the material. [Brief description of the drawings]
[0021] Fig. 1 is a schematic view of a pattern illustrating a part to be cut from a sheet of material, according to embodiments of the invention;
[0022] Fig. Figure 2 is a schematic representation of a laser cutting system for cutting material supported on a support structure according to exemplary embodiments of the invention;
[0023] Fig. Figure 3 is a schematic representation of preprocessing intersection lines in the pattern according to embodiments of the invention;
[0024] Fig. Figure 4A is a flowchart of a method for determining whether locations are inside or outside a section, using a rasterization preparation process according to embodiments of the invention;
[0025] Fig. Figure 4B is a schematic representation of results for a counting process for rasterization for sampling locations according to exemplary embodiments of the invention;
[0026] Fig. 4C is a schematic representation of results for a counting process for rasterization for sampling locations according to the embodiments of the invention;
[0027] Fig. Figure 5A is a flowchart for a method for determining whether locations are inside or outside a section, using a ray tracing processing process according to embodiments of the invention;
[0028] Fig. Figure 5B is a schematic representation of the results of a counting process for ray tracing for sampling locations according to the embodiments of the invention;
[0029] Fig. Figure 6 is a schematic representation of an exemplary part with nested cutouts and a corresponding hierarchical tree structure that defines a nesting sequence for the exemplary part, according to the embodiments of the invention;
[0030] Fig. 7(a) to Fig. Figure 7(c) shows schematic representations of the circumvention by a cutting head in order to avoid previously cut sections, according to the embodiments of the invention; and
[0031] Fig. Figure 8 is a schematic representation for creating and deleting connections between cutouts and a material in order to avoid previously cutouts, according to the embodiments of the invention. [Description of exemplary implementations] Part, pattern and excerpts
[0032] Fig. Figure 1 shows a pattern for a single sheet of paper 20 from material using a laser cutting device 90 part to be cut out 10Patterns are typically read from a CAD / CAN / CAM file that defines the individual components, such as arcs, lines, or circles, among other possibilities. The sheet is typically placed on a support structure. In some applications, the structure can support multiple sheets, all of which are cut simultaneously. The support structure typically includes vertically spaced sections to allow for the removal of offcut material and prevent collisions with the cutting head.
[0033] The part is defined by an outer outline. 30 and inner outlines 40 Defined by the sections to be cut and the areas to be removed from the material. The outlines are formed by straight or curved lines. Some cutouts 50They cannot fall through the support structure because the cutouts are larger than the free space in the support structure or have irregular shapes that can catch on the edges of the support structure. In any case, such cutouts can collide with the cutting head. Overview of laser cutting system
[0034] Fig. Figure 2 shows the preceding section 50 essentially perpendicular to a plane of the sheet 20 on the support structure 60 Since the free space 201 If the cutout is too small in the support structure, it cannot be removed and cut with the cutting head. 90 Collide. This can also occur with irregularly shaped cutouts that interact with the part or the supporting structure.
[0035] Fig. 2 also shows how a pattern 401 , Excerpts) 411 and place(s) 402 in a procedure 200can be entered into a processor 210 A process is performed to determine whether a location is inside or outside the defined area, as described in detail below. The processor includes memory and input / output interfaces, as known in the prior art. The memory can store an array of locations with associated values, as described here.
[0036] The inside / outside indicators can be used to monitor the movement of the cutting head. 90 to control the movement so that previously cut sections can be avoided. The movement can be controlled by a control device. 95 This can be carried out. The control device can move the head sideways / upwards / downwards and switch the laser on and off. An attached capacitive sensor can also be used. 92 It is designed to indicate the exact location of the sensor above the material to be cut.
[0037] The movement can also take into account nested cutouts as well as connections between partially cut cutouts and the material, so that cutouts can be held in place by the connection while other cutouts are cut until it is safe to remove the connection from the partially cut cutout.
[0038] Multiple locations can be checked for one or more cutouts. Additionally, the locations relative to the cutouts can also be used to determine whether some cutouts are nested within other cutouts, as described below. This can aid in bypassing the cutting head.
[0039] Due to the potential costs associated with collisions, it is highly desirable to avoid head movements that could lead to collisions. We first describe two methods for accurately identifying inner and outer locations relative to a closed section to be cut. Subsequently, we also describe methods and solutions by which the laser cutting head moves around areas where collisions could potentially occur. Identifying the location as inside / outside
[0040] We describe two embodiments of a method that allows the evaluation of locations within the part under test to determine whether they are enclosed by an arbitrarily closed section. With these embodiments, it is now possible to perform the following: (a) Determining the exact shape and position of a section to be cut out of the sheet; (b) Determining a nesting pattern for the part, i.e., which cutouts are nested within other cutouts; (c) Determining a cutting sequence for the cutouts; and (d) Retaining connections between cutouts that are partially cut out of the material.
[0041] By using (a), it is possible to identify locations to avoid when moving the cutting head. By using (b), the nested cutouts can be placed in a cutting sequence to prevent cuts being made within previously cut cutouts, which can lead to collisions, and connections can be held back to keep partially cut cutouts in place until it is safe to cut out the cutouts. Processing
[0042] Both methods employ a processing technique applied to the viewports. One process uses rasterization, the other ray tracing. The processing is adapted from graphic processing techniques, as described above. However, instead of generating pixel appearance values for the field in the frame buffer, the "pixel" values indicate whether locations are inside or outside a viewport according to specific field coordinates. This differs from the appearance known from prior art processing techniques. Grid
[0043] The first implementation of the processing method uses rasterization. Rasterization maps polygons onto an image plane, or an array of pixel values. Typically, the polygons are represented as collections of triangles. The triangles are represented by three vertices. At a very basic level, rasterization devices, such as a processing pipeline, simply take the stream of vertices and fill the pixels in the triangles accordingly.
[0044] The second embodiment uses ray tracing for processing. Ray tracing follows a path from a point along the (viewing) direction of the ray in the material plane and determines intersections with the section, such as intersection boundaries (outlines).
[0045] The addresses in the field correspond to the coordinates of locations in the sheet material. Both processing methods assign values in the field to either odd or even numbers through a counting process, as described here. The odd and even values are associated with inner and outer locations, respectively. The inner and outer odd / even indications can be used to control the movement of the laser cutting device. It should be noted that the meaning of the odd / even values can be reversed depending on the initial value used. Preprocessing of intersecting lines
[0046] Before processing, as in Fig. As shown in Figure 3, the pattern for the part is pre-processed as follows. When two lines 301 When lines intersect, they will be separated at the point of intersection. 303the two lines were split to create four new, shorter lines. 302 to create. Overlapping lines or line segments are removed. Preprocessing allows for the precise creation of separate sections. Identifying sections
[0047] Segments in the pattern can be identified in any number of ways. A path begins at the rightmost point of a union of all things in the pattern, e.g., lines, and traverses the pattern by visiting subsequent line endpoints in a consistent manner.
[0048] If no new location can be visited that is different from the previous one, the segment is identified as an open segment, and associated lines are removed from the segment. If a previously visited location is encountered, the segment is marked as closed. In this way, a pair of segments is either nested or separate, although the features may share parts of their outlines.
[0049] Additionally, after this process, closed cutouts now have a minimally straight outline. Other preprocessing methods are possible depending on the application. Grid
[0050] Fig. 4A shows a first embodiment of a method for determining whether locations 402 inside or outside the cutout 411 one from the laser cutting machine 90 used pattern 401are. Of particular interest are cutouts within a closed outline (closed cutouts). Closed cutouts should be avoided after cutting. The cutout 411 and the place to be processed 402 will be selected 410 .
[0051] In the raster-based processing 400 The outline of the section is defined by a list of outline vertices. 221 shown 420 As commonly used here, a list is any ordered set of items. The vertices may be evenly spaced along the outline, although this is not required.
[0052] A list of polygons, e.g. triangles 431 is educated 430 using the outline vertices. The polygons are rasterized. 440 as a field stored in a memory 441During rasterization, the number of times a location is rasterized is counted, as described above. This can be done using a graphics processing unit (GPU), which makes the process extremely fast. The array has addresses that correspond to the coordinates of the locations. Each location corresponds to one pixel. 450 Then it can be determined 450 , whether the place 402 inside or outside the cutout 411 is by changing the value of the field 441 at the relevant location 402 is being checked.
[0053] In the processing example, lines in the pattern that are associated with the cutout are represented by vertices such that straight line segments between two adjacent vertices approximate the lines piecewise.
[0054] The vertices are used to form the list of polygons (triangles) that exactly cover all locations within the section. The path by which the triangles are formed is arbitrary.
[0055] The Fig. 4B– Fig. Figure 4C shows exemplary components used to create a list of (exaggerated) tessellated triangles. The components were prepared using the rasterization method to determine effective inner and outer locations. The level of tessellation can be controlled to achieve piecewise linear approximations to any desired accuracy—up to the limits of digital representation.
[0056] The list of triangles is processed into the field. Effectively, each address in the field can be represented by a pixel. 450 They can be obtained. The pixels are handled as follows.
[0057] Initially, the value at each field address is zero or another known value. One possible processing technique counts the number of times a specific pixel (location) is visited. 450 within a prepared triangle, see for example Fig. 4B– Fig. 4C. The count values are shown within the pixels, i.e., the addresses in the field according to the locations.
[0058] This can be done by incrementing the values stored at the pixel. Another processing technique uses a single bit at each address and inverts its value (0 or 1) each time the pixel is processed as part of a triangle. Both incrementing and inverting can be viewed as counting processes, with inverting a bit counting in base-2 arithmetic.
[0059] In any case, after the section has been prepared, the addresses will have either odd or even values due to our counting process. The odd and even values correspond to the inner and outer locations, respectively. These values can be used to plan and control the movement of the cutting head.
[0060] The Fig. 4B– Fig. Figure 4C shows the resulting odd / even count values for example locations and triangles that are used by the counting process for processing. Radiation tracking
[0061] As in Fig. As shown in Figure 5A, the second embodiment is similar to the first embodiment in that a counting process is used to determine field values during processing. However, instead of rasterizing polygons, the second embodiment uses ray tracing during processing. 400 .
[0062] As above, the excerpt 411 and the 2D location 402 selected. At least one beam. 521 is emitted from that location in any (viewing) direction. 520 . Every intersection between the ray and any outline of the section is detected. 530 and counted, see for example Fig. 5B. Then, based on the recorded number of intersections, a determination is made. 540 , whether the 2D location is within the cutout.
[0063] The acquisition process uses the field's stored value, as described above. The values are initialized to zero. The rays can be directed in any direction. Conveniently, the ray sizes limit the ray to within the pattern plus a small margin. If the ray has an odd number of intersections, the location is inside; otherwise, the location is outside.
[0064] To determine whether a specific location is contained within the cutout, only a single beam needs to be emitted. If the beam crosses the cutout outline only once (odd number of times), the location must be inside; if it crosses twice, the count is even, and the location is inside. Analytical techniques can be used in many cases to determine the intersections between the beam and lines of the cutout, such as arcs and lines. In the case that the closed cutout is composed of higher-order curves, iterative methods can be used to count the number of intersections.
[0065] Fig. Figure 5B shows the resulting odd / even pixel values for locations in a sample component and rays used by the counting process for ray tracing. Fig. 5B is for the same component as in Fig. 4C shown, but this time processed using rasterization. Cutting head with capacitive sensor
[0066] Sometimes it is not sufficient to consider a single location as either inside or outside a given cutout, as some laser cutting heads have a tolerance that allows the head to extend across gaps in the material being cut. This is the case with laser cutting heads that have an attached capacitive sensor. 92 To determine a geometric relationship between the sensor head and the material, e.g., distance and location, it is often the case that a predetermined area of the capacitive sensor covers the material; for example, the area might be approximately 50% or more.
[0067] The current method can be improved to handle such situations by considering a neighborhood of locations around the head position and directly below the capacitive sensor of the laser cutting device. If the percentage of locations in the neighborhood considered outside the cutout exceeds a minimum threshold, then the head position can be considered safe for centering the laser cutting head. Addressing problem areas through workarounds
[0068] Once areas of concern have been identified, it can be determined to avoid them by employing a "workaround strategy." Ideally, this strategy avoids the use of slow head-up and head-down movements. We describe the following procedures, which avoid both collisions and head-up / head-down movements.
[0069] Although we describe our invention with reference to material areas that should be avoided due to the presence of waste material that could lead to a collision with the laser cutting head, there may be additional material areas that should be avoided by the laser cutting head.
[0070] Such areas, which we generally refer to as “no-walking zones”, can also be avoided using the methods described in the following inventions. The no-walking zones can be specified by the locations determined as above. Locations of the path that cross and violate the no-walking zones are avoided and removed in such a way that the laser cutting device bypasses the no-walking zone when lateral movements are performed while cutting the cutouts. Cutting according to nesting order
[0071] If all locations within a closed section are determined, then it is possible to determine whether one section is nested with another section.
[0072] Using the preparation procedures described above, one, some, or all locations on the boundary of the cutout are checked for inclusion. If a given cutout is contained within any other cutout, it is completely within that other cutout. If every cutout is checked for inclusion in every other cutout, a hierarchical nesting tree can be constructed, corresponding to the nesting relationship between all cutouts in a pattern. In the tree, each node represents a cutout, and a root of the tree corresponds to a portion or other collection of the cutouts.
[0073] Fig. Figure 6 shows an example of a nesting relationship where sections n601 – 603 each within the section 600 are nested, and the section4 604 is within section 2 602 Nested. The nesting order of the multiple cutouts determines how the cutting head bypasses them.
[0074] Once the nesting relationship between the cutouts in a part is known, a cutting order can be determined to avoid collisions. The cutting order follows an inverse hierarchy of the tree; that is, the cutouts are cut in a bottom-up order of the tree, and cutouts at the same level of the tree can be cut in any order or in a predetermined order as described below.
[0075] This method is insufficient to avoid all collisions, but it is necessary to ensure a proper cutting order. One method for generating a cutting order that obeys the nesting order is to perform a first depth-first search of an ordered stack such that each cut is added to the cutting list when it is output from a last-input, first-output stack. border bypass
[0076] Cutouts that do not have a specific nesting relationship with other cutouts are also a potential source of collisions when lateral cutting head movements are performed between cutouts. In such cases, potential collisions can be determined by considering whether locations along the paths of lateral movement consistently lie within a cutout that was previously cut.
[0077] When such a situation arises, a workaround strategy is employed. As previously described, this strategy involves switching off the laser, followed by raising the laser head to a safe height, performing the rapid lateral movement, and then lowering the head and switching the laser back on to continue cutting. While effective, this measure is suboptimal because it requires additional time.
[0078] As in the Fig. 7(a)– Fig. Figure 7(c) shows a better bypass strategy along a path following an outline of the previously cut section, which is crossed at a predetermined distance from the outline during lateral movement, the predetermined distance ensuring that no collision occurs between the cutting head and the section.
[0079] As in Fig. As shown in 7(a), a previously cut section is shown. 700 potentially through a single, straight lateral movement 710 from the place 701 to the place 709 of another section to be cut 711 crossed.
[0080] As in Fig. As shown in 7(b), the lateral motion path is defined by a single straight segment. 710 into a series of segments 701 – 709 transformed, following the outline of the cutout. This lateral movement can be created by: (1) Marking the entry and exit points 702 and 708 for a specific section for the original fast lateral movement 710 ; (2) Determining a shortest direction of movement around the cutout between the entry and exit points; (3) Replacing the original rapid lateral movement 710through a series of short segments that mimic the cutting movements, exhibiting the followed outline of the cutout; and (4) Extend these segments away from the cutout boundary to ensure that a collision between the cutting head and the previously cut section cannot occur.
[0081] The lateral movement generated by the strategy described above does not necessarily have to be the optimal movement to avoid crossing the previously cut section, as it may include several stopping, reversing and starting movements.
[0082] As in Fig. As shown in 7(c), another strategy truncates the series of short segments so that only the locations 701 , 704 , 706 and 709 Only the areas absolutely necessary to avoid the cutout will be retained.
[0083] This can be achieved by starting with the first location along the lateral movement, checking the starting location of each segment exhibiting the lateral movement against the starting location of each subsequent segment to determine if a previously cut section is crossed. It is important to note that all cuts should be checked for crossings, not just the original cut.
[0084] If a segment is found that does not cross any existing segment, it becomes a candidate to replace the segments it spans. A new segment can then be created that connects the starting point and the last point reachable without crossing the existing segment. The checks then continue from the endpoint of this new segment.
[0085] For example, following the markings in the second illustration, the location 701 opposite 703 , 704 (okay), and 705 , 706, 707 , 708 , 709 (not OK) checked, resulting in a new segment between the locations 701 and 704 is created; then the place will be 704 opposite 706 (in order) and 707 , 708 , 709 (not OK) checked, causing a segment from the location 704 to the place 706 is produced; the place 706 will then be opposite the place 708 (not OK) and 709 (OK) checked, which leads to a segment that shows the location 706 with the place 709 connects. Thus, a new lateral movement is created. 712 generated with a minimal number of segments, successfully avoiding any potential collision between the laser cutting device and the previously cut section.
[0086] Alternatively, a spline can be adapted to the remaining locations to create a smooth curved path. 712to generate. The curved path is shown in dashed lines, and the minimum short straight segment path by solid lines. However, for this strategy to be effective, the control device on which the G-code is executed must be capable of performing such movements. Crossover procedure with residual connection
[0087] As in Fig. As shown in Figure 8, another method for avoiding collisions with previously cut sections involves delaying a cut that would otherwise separate the section from the material until no further intersections are possible. Such a strategy can be implemented in various ways.
[0088] We describe a preferred method that leaves small “connections” between cutouts and the material from which the cutouts are partially cut.
[0089] Fig. Figure 8 shows an example of this procedure for the part 600 The dashed line indicates the output of a previous CAM stage, following the nesting order of the cutouts, and starts in the lower left corner. The laser begins cutting the two middle cutouts. 602 and 604 to cut, and then the “plus” cutout 603 , but if he positions himself between the plus and the triangle cutout 601 As it moves, it crosses two previously partially cut sections. Such a lateral movement could lead to a collision between the cutting head and the material.
[0090] Instead of working around the gap in the material left over from cutting out the sections, we can temporarily turn off the laser during the initial cutting process at the intersection between the cutout and the final movement that crosses the cutout. This results in a few (at least two) small connections, thick line. 800 , hold the cutout against the material, thus avoiding the creation of the gap that could otherwise cause problems.
[0091] Then, during the final movement, the laser is temporarily switched ON while the connections that were maintained are crossed. Therefore, when using this method, crossing a previously cut-out section is prevented, since the section is not completely cut out of the material until the last lateral crossing movement, after all sections have been partially cut out.
[0092] The steps of all the procedures described above can be found in the Fig. 2 processors shown 210 The procedures can also be implemented using OpenGL, a template buffer, and a frame buffer. Effect of the invention
[0093] The invention advantageously enables the cutting of sections from sheet materials without the use of slow up / down movements of the cutting head of the laser cutting machine, while avoiding collisions.
[0094] Furthermore, the processing techniques can advantageously utilize extremely fast, conventional processors such as GPUs, processing pipelines, or parallel multi-core CPUs.
[0095] The invention can also minimize the time required to bypass previously cut sections.
Claims
[1] Method for modifying a path of a cutting head of a laser cutting machine for cutting sections according to a pattern from a material, comprising the steps: Determining a no-walk zone that the cutting head avoids while making lateral movements between cuts; Determining the path for the cutting head to cut the sections; Determining locations on the path that cross the no-entry zones; and Modifying the path such that all locations violating the no-walk zone are removed so that the cutting head avoids the no-walk zone when performing the lateral movements, with the steps being carried out in a processor. [2] Method according to claim 1, wherein the lateral movements crossing the non-walking zone are replaced by alternative lateral movements following an outline of the non-walking zone at a predetermined distance from the outline. [3] Method according to claim 2, further comprising: Marking entry and exit points for the no-entry zone and the lateral movements that cross the no-entry zone; Replacing the lateral movements of the cutting head with a series of alternative movements that mimic an outline of the non-traffic zone; and Extending the alternative movements away from the outline of the no-entry zone. [4] Method according to claim 3, further comprising: Determining a shortest direction of movement around the non-travel zone between the entry and exit points; and Replacing lateral movements that cross the no-entry zone with movements that follow the outline of the no-entry zone in the shortest direction of movement. [5] Method according to claim 3, further comprising: Restricting alternative movements to the use of only those locations that are absolutely necessary to avoid the no-entry zone. [6] Method according to claim 1, wherein the non-walking zone is a gap in the material where the cutouts were made by prior movements of the cutting head. [7] Method according to claim 6, further comprising: Modifying the path for each subsequent cutout, after the cutouts have been cut in such a way that the lateral movements of the cutting head avoid the cutout. [8] Method according to claim 7, further comprising: Maintaining connections between the cutouts and the material from which the cutouts are partially cut. [9] Method according to claim 8, further comprising: Cutting the connections after all known unsafe crossings have been carried out from each of the cutouts. [10] The method of claim 1, wherein the determination of the locations further comprises: Processing, at each location of the section into a field stored in a memory such that a value stored at an address in the field, corresponding to the coordinates of the location, determined by a counting process of the processing, is either odd or even; and Identify each location as inside if the value is odd, and as outside if the value is even.