Method and system for automatically cutting defective portions in a fabric with a pattern

Abstract

The invention relates to a method and a system for automatically cutting defective pieces in a patterned fabric, the pattern being repeated at a certain pitch, comprising the steps of generating a theoretical layout of the pieces to be cut on a theoretical representation of the fabric while respecting layout constraints, laying at least one layer of the fabric on a cutting table, inspecting at least a portion of the laid fabric to determine actual features, modifying the theoretical layout to generate an actual layout taking into account the actual features of the fabric, identifying defective pieces in the actual layout, the identification of a defective piece being such that the piece, if cut in the fabric, would contain a defect and would need to be recut, automatically assigning each defective piece to a new theoretical layout by adapting the layout constraints related to the defective piece according to the actual layout.

Description

Technical Field

[0001] This invention relates to the general field of automatically cutting sheets of patterned fabric, wherein the pattern is repeated at a certain interval, referred to as the pattern spacing. In particular, this invention relates to the management of defective sheets that, once cut in the fabric, would contain defects and require recutting.

[0002] In particular, this invention is applied to the clothing and furniture industries. Background Technology

[0003] When the production of clothing or furniture involves the assembly of sheets cut from fabric, there are special constraints if the fabric is patterned. Here, "patterned fabric" refers to any flexible sheet-like textile material printed with regular patterns that repeat at predetermined intervals.

[0004] Therefore, in this case, it is necessary, even essential, to consider the continuity of the patterns between the two assembled sheets.

[0005] As is well known, in order to comply with these constraints, absolute or relative positional markers must be associated with the sheet material, and a hierarchy must be established between primary and secondary sheet materials.

[0006] Absolute position markings are typically associated with the main sheet and are characterized by the absolute position of the main sheet relative to the fabric pattern. The position of a sheet relative to the pattern is characterized by a given point on the sheet surface occupying a specific relative position relative to the pattern, around which the pattern revolves. Therefore, the positions of the individual sheets on the fabric surface are derived from each other by translating an integer number of pattern spacings, with these sheets occupying the same position relative to the pattern.

[0007] Considering the requirements associated with the presence of the pattern, relative position marks are associated with the two sheets that need to be assembled. These relative position marks determine the positions of the two corresponding connection points that must be maintained during the sheet assembly process.

[0008] For example, in the case of a jacket, the back panel can serve as the main panel. Optionally, absolute positional markings are associated with the back panel, for example, when it is desired that the full pattern can be seen at a specific location on that panel. The sleeves, collar, and front can then form secondary panels, and the position of the connection point for each of these secondary panels is determined to correspond to the position of the associated connection point on the main panel.

[0009] Furthermore, the sheet associated with the relative position mark can also be the main sheet of one or more other sheets, in which case it is referred to as a connecting chain. Similarly, the sheet can have absolute or relative position marks, or no position marks, on the axis of the weft threads of the fabric, and another type of position mark (i.e., relative, absolute, or no position marks) on the axis of the warp threads of the fabric.

[0010] In addition, it is known that fabrics can be cut automatically, and the applicant has been selling automatic cutting equipment for many years.

[0011] Typically, automated cutting methods include a layout operation that optimally determines the positions of the pieces to be cut within a fabric. The layout is chosen to minimize fabric loss while adhering to certain constraints, such as conforming to the grain and having sufficient minimum allowance between pieces. In the case of patterned fabrics, additional constraints related to adherence to absolute and relative position markers are required. Systems that enable operators to define layouts using computer workstations and specialized software are known, including for patterned fabrics.

[0012] For cutting, the fabric is laid on the cutting table in one or more overlapping layers and held in place by the suction of the cutting table. Cutting is performed using a tool carried by a head, the movement of which is controlled by a predetermined layout relative to the cutting table. Cutting can be performed using vibrating blades, rotary blades, lasers, water jets, etc.

[0013] Difficulties arise when using patterned fabrics. In particular, discrepancies often occur in practice between the fabric model used for layout and the actual fabric laid out on the cutting table. These discrepancies are especially evident when one stands at the coordinates of a reference point on the layout of a piece of fabric on the cutting table. It becomes apparent that the corresponding point on the laid-out fabric does not always occupy the expected position relative to the actual fabric pattern. These differences are often significant and difficult to avoid in practice. They are caused by printing defects, positioning defects of the fabric on the cutting table, and variations in loom linear density and / or fabric deformation that lead to irregular pattern repeating spacing. Therefore, the pre-established or theoretical layout must be modified to correspond to the actual fabric laying.

[0014] Document EP 0759708, submitted in the applicant's name, describes a method for automatically performing such layout modifications. After laying the patterned fabric on a cutting table, this method envisions detecting any offset between the actual spacing of the patterns on the fabric and their theoretical spacing by acquiring an image of a portion of the laid fabric and checking whether the positions corresponding to stored information on the acquired image occupy the desired positions relative to the actual patterns on the laid fabric. If necessary, the theoretical layout of the sheet is modified based on the verification results to adjust the actual spacing of the patterns on the laid fabric, taking into account the actual characteristics of the fabric.

[0015] Once the actual layout of a set of sheets on a portion of the fabric is generated, the cutting stage for that set of sheets begins. However, this stage presents numerous challenges, particularly with the fabric to be cut. In fact, this fabric frequently exhibits defects, tears, and material fading in certain locations. When sheets in the layout are cut at these locations, they become unusable and require recutting. Similarly, modifications to the layout of the sheets to be cut sometimes result in the repositioning of the sheets, where some adjacent sheets overlap. In this case, the sheets become unusable and require recutting. In practice, these issues necessitate that the operator recut all relevant sheets in the layout (hereinafter referred to as "defective sheets") at the end of the cutting stage.

[0016] Typically, after other pieces of fabric in the layout have been cut, the operator manually cuts the defective pieces that need to be cut again. In practice, the operator cuts a sample piece from a roll of fabric and manually cuts the defective piece. However, this manual cutting proves particularly complex when the defective piece is a sub-piece, because the sub-piece is associated with relative layout constraints relative to the parent piece. In fact, in this case, the operator must manually establish the connection by finding the parent piece and the connection between the parent piece and the sub-piece to be cut again, and then manually transfer this type of constraint to the sample piece of fabric to be cut again. Furthermore, these operations may need to be repeated.

[0017] This manual re-cutting method has many drawbacks. First, the automated cutting process is interrupted. Furthermore, material usage is not optimized (leading to fabric waste), and the connection quality of the fabric pattern often lacks precision. Summary of the Invention

[0018] Therefore, the present invention aims to provide a method for automatically cutting defective pieces in patterned fabrics, wherein the defective pieces are automatically cut again.

[0019] According to the present invention, this objective is achieved by a method for automatically cutting defective sheets of patterned fabric, wherein the pattern is repeated at a certain interval, referred to as the pattern spacing. The method includes the following steps:

[0020] While adhering to the layout constraints associated with the sheet to be cut, a theoretical layout of the sheet to be cut is generated on the theoretical representation of the fabric.

[0021] At least one layer of the fabric is laid on the cutting table;

[0022] Determine the actual characteristics of at least a portion of the laid fabric;

[0023] Taking into account the actual characteristics of the fabric, the theoretical layout is modified to generate the actual layout of the laid-out fabric sheet;

[0024] In the actual layout, defective sheets are identified, which, once cut into the fabric, would contain defects and require further cutting; and

[0025] By adjusting the layout constraints associated with the defective sheet according to the actual layout, each defective sheet is automatically assigned to a new theoretical layout.

[0026] According to the method of the present invention, it is characterized by automatically re-cutting the defective sheet material by allocating it to a new layout. This allocation is performed to preserve the layout constraints of the defective sheet material so that it can be adjusted according to the actual layout. In other words, the method provided by the present invention transforms the layout constraints of the defective sheet material on the laid fabric into positioning constraints for the new layout, in which the defective sheet material will be re-cut.

[0027] In particular, the method provided by this invention has the advantage that the recutting of defective sheets is fully automated, thus eliminating the need to interrupt the automatic cutting process. Furthermore, this automation optimizes material usage to reduce waste and ensures high precision in the connection quality between fabric patterns.

[0028] Preferably, each of the pieces to be cut is associated with a reference point and a layout constraint on the fabric, the layout constraint being selected from the following constraints:

[0029] a) Absolute constraint, wherein the position of the reference point of the sheet relative to the fabric pattern is determined such that the fabric pattern appears at the desired position on the sheet;

[0030] b) Relative constraint, wherein the position of a reference point of a sheet called a sub-sheet relative to the connection point of another sheet called a mother sheet is determined, such that the position of the reference point of the sub-sheet relative to the fabric pattern is the same as the position of the connection point of the mother sheet;

[0031] c) Relative symmetry constraint, wherein the position of a reference point, referred to as a sub-sheet, relative to the connection point of another sheet, referred to as a mother sheet, is determined, such that the position of the reference point of the sub-sheet relative to the fabric pattern and the position of the connection point of the mother sheet are pattern-symmetrical; and

[0032] d) Free constraint, wherein the position of the reference point of the sheet relative to the fabric pattern is free.

[0033] When the defective sheet is a sheet related to the absolute constraint (as described in case a above), the automatic allocation of the defective sheet to a new theoretical layout includes: retaining the absolute constraint relative to the fabric pattern in the new theoretical layout.

[0034] When the defective sheet is a sub-sheet associated with the relative constraint or the relative symmetry constraint relative to the mother sheet that does not need to be cut again (as described in case b) or c) above, the automatic allocation of the defective sheet to a new theoretical layout includes: converting the relative constraint into the absolute constraint in the new theoretical layout so that the position of the reference point of the sub-sheet relative to the fabric pattern and the position of the reference point of the sub-sheet in the actual layout are consistent.

[0035] When the defective sheet is a parent sheet associated with at least one relative constraint or at least one relative symmetry constraint relative to one or more subsheets (as described in case b) or c) above, the automatic allocation of the defective sheet to the new theoretical layout further includes: automatically allocating the one or more subsheets to the new theoretical layout.

[0036] When the defective sheet is a sheet associated with the free constraint, the automatic allocation of the defective sheet to a new theoretical layout includes: in the new theoretical layout, there is no positional constraint of the reference point of the sheet relative to the fabric pattern.

[0037] In the end region of the actual layout, the new theoretical layout of the defective sheet is calculated and cut according to the direction of the fabric's movement on the cutting table.

[0038] The new theoretical layout of the defective sheet is incorporated into the subsequent layout according to the direction of the fabric's movement on the cutting table.

[0039] The defective sheet material can be:

[0040] After the actual layout is generated, the sheet material located on the defect of the already laid fabric; or

[0041] After the actual layout is generated, the sheet material overlapping with another sheet material in the layout; or

[0042] After the actual layout is generated, the sheet material located in the area where the laid fabric has a large deformation; or

[0043] After the actual layout is generated, there are pieces of fabric that cannot be completely cut within the laid fabric; or

[0044] After the actual layout is generated and cut, the sheet material has cutting defects; or

[0045] After generating the actual layout, sheet material with geometric defects; or

[0046] The sub-sheet material associated with the relative constraint or the relative symmetry constraint, relative to the defective master sheet material that needs to be cut again.

[0047] The defective sheet material is not cut within the laid fabric.

[0048] The present invention also relates to a system for automatically cutting defective pieces in a patterned fabric, the pattern being repeated at a certain interval, the interval being referred to as the pattern spacing, the system comprising:

[0049] A tool for generating a theoretical layout of the sheet to be cut on a theoretical representation of the fabric while adhering to layout constraints associated with the sheet to be cut;

[0050] A cutting table on which at least one layer of the fabric can be laid;

[0051] A tool for determining the actual characteristics of at least a portion of the laid fabric;

[0052] A tool for modifying the theoretical layout to generate an actual layout of the laid-up fabric sheet while taking into account the actual characteristics of the fabric;

[0053] Tools for identifying defective pieces in the actual layout, the defective pieces containing defects once cut in the fabric and requiring recutting; and

[0054] A tool for adjusting the layout constraints associated with the defective sheet according to the actual layout, thereby automatically assigning each defective sheet to a new theoretical layout. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of an example of a fabric with a repeating pattern to which the present invention is applicable;

[0056] Figure 2 An example of the theoretical layout of the sheet material to be cut is shown;

[0057] Figure 3 It shows how to modify Figure 2 The theoretical layout is shown in a way that generates the actual layout;

[0058] Figure 4 This illustrates the process of removing defective sheet material (with free constraints) from... Figure 3 The example shown is an instance of an actual layout being automatically assigned to a new theoretical layout;

[0059] Figure 5 This illustrates the process of removing another defective sheet (with relative constraints) from... Figure 3 The example shown is an instance of an actual layout being automatically assigned to a new theoretical layout;

[0060] Figure 6 This illustrates the process of separating two connected defective sheets from... Figure 3 The example shown is an instance of an actual layout being automatically assigned to a new theoretical layout. Detailed Implementation

[0061] The present invention relates to cutting a layout of a set of sheets in a fabric having a repeating pattern, the set of sheets being intended to be cut by an automated cutting device such as that described in published EP 0759708.

[0062] More specifically, the present invention relates to the automatic cutting of so-called “defective flakes” in a fabric having a pattern that repeats at regular intervals.

[0063] The initial steps of this method include characterizing the fabric containing the sheets to be cut. This step can be achieved by manually measuring the fabric, relying on information provided by the manufacturer, or automatically identifying and characterizing the pattern by scanning material strips; such as grid number, warp spacing, weft spacing, and offset.

[0064] Examples of fabrics with repeating patterns to which this invention is applicable include: Figure 1 As shown.

[0065] refer to Figure 1 It shows a fabric T with a repeating pattern M having a main grid G1 and two secondary grids G2 and G3. These grids G1 to G3 are offset relative to each other in both the warp and weft directions (X-axis represents the warp, Y-axis represents the weft). In particular, the pattern M is characterized by its warp spacing PC and its weft spacing PT.

[0066] Record information extracted from the characteristics of fabric T to define a theoretical grid for generating the theoretical layout of the sheet.

[0067] The theoretical layout involves determining the position of the sheet material to be cut on a theoretical grid to minimize material loss while adhering to certain constraints (following the texture, minimum spacing between the sheet materials to be cut, etc.).

[0068] In the case of fabrics with repeating patterns, aesthetic requirements may, on the one hand, require the complete pattern to be presented in specific locations on certain pieces of fabric, and on the other hand, for two pieces of fabric to be assembled, the cutting of these pieces needs to ensure, for example, the continuity of the pattern after assembly.

[0069] Therefore, it is known that the characteristics of each sheet in the layout are determined by assigning an initial profile, a reference point, and at least one layout constraint to each sheet.

[0070] Once the theoretical characteristics of the fabric and the information related to the different sheets in the layout are determined and recorded, the theoretical layout of the sheets can be generated based on the layout constraints related to the sheets.

[0071] Figure 2 An example of the theoretical layout generated for four pieces P-1 to P-4 to be cut in fabric T is shown. In particular, the fabric T has weft threads M1, M2, M3, etc., that repeat as a pattern at predetermined intervals p.

[0072] Each of the sheets P-1 to P-4 is assigned an initial profile, namely Ci-1, Ci-2, Ci-3, and Ci-4, respectively. These initial profiles are typically defined by computer-aided design software (CAD) in a form without any allowances. These profiles are represented by polygons (rectangles in this application).

[0073] The reference points O-1, O-2, O-3, and O-4 are also associated with each piece P-1 to P-4 in the layout and at least one layout constraint of that piece on the fabric.

[0074] Regardless of the layout constraints used, the reference point for each sheet is defined by the operator. The reference point is a point on the sheet that is important for positioning.

[0075] The layout constraints are selected by the operator from one of the following layout constraints:

[0076] 1) Absolute constraint:

[0077] This constraint is associated with a piece of fabric that must be precisely positioned on the fabric so that the fabric pattern appears in the desired location on that piece of fabric.

[0078] For this constraint, the position of the reference point of the sheet relative to the fabric pattern is predetermined. Therefore, in Figure 2 In the implementation shown, sheet material P-1 and sheet material P-2 have absolute layout constraints. The reference point O-1 of sheet material P-1 is located on the latitude line M3, while the reference point O-2 of sheet material P-2 is located on the latitude line M5.

[0079] 2) Relative constraints:

[0080] This constraint is associated with a first piece of fabric called the “sub-piece”, the position of which on the fabric is determined by the position of a second piece of fabric called the “mother piece”.

[0081] For this constraint, the position of the reference point of the sub-sheet is determined relative to the connection point L of the mother sheet, such that the position of the reference point of the sub-sheet relative to the fabric pattern is the same as the position of the connection point of the mother sheet.

[0082] exist Figure 2 In the example, sheet material P-3 is a daughter sheet material of sheet material P-2 (the mother sheet material). Therefore, the mother sheet material P-2 has a connection point L-2 that can locate the daughter sheet material P-3 at reference point O-3.

[0083] The distance d between point L-2 and parallel M11 is located at 75% of the distance between parallels M11 and M12. Therefore, the distance d between point O-3 and the parallel must also be a parallel. In this example, point O-3 is located between parallels M3 and M4, and its distance from parallel M3 is d.

[0084] Similarly, still Figure 2 As shown, sheet material P-4 is a daughter sheet material of sheet material P-3 (mother sheet material). Therefore, mother sheet material P-3 has a connection point L-3 that can position the daughter sheet material P-4 at reference point O-4.

[0085] It should be noted that since the same sheet material may be the parent sheet material of multiple sub-sheet materials, it may contain multiple connection points.

[0086] 3) Relative symmetry constraints:

[0087] This constraint is also associated with the first piece of fabric, known as the "sub-piece," whose position on the fabric is determined by the position of the second piece of fabric, known as the "mother piece."

[0088] Compared to relative layout constraints, the position of the reference point of the sub-sheet is determined to be symmetrical to the pattern of the connection point relative to the parent sheet.

[0089] 4) Freedom Constraints:

[0090] This constraint is associated with the sheet material, whose position relative to the fabric pattern is free (i.e., there is no relative or absolute constraint).

[0091] With this constraint, the position of the reference point of the sheet relative to the fabric pattern is free.

[0092] Once the information related to the theoretical characteristics and layout of the fabric and the different sheets has been identified and recorded, the theoretical layout of the sheets can be generated based on the layout constraints associated with the sheets.

[0093] The characterization of each sheet and the generation of its theoretical layout are typically performed by an operator using a computer workstation equipped with appropriate software. The theoretical layout and characteristics of the sheet are also stored.

[0094] The following steps involve laying at least one layer of fabric T on a cutting table, wherein the layout will be cut, and then inspecting at least a portion of the laid fabric to determine whether the resulting theoretical layout is correct, and making corrections if necessary.

[0095] The inspection typically involves placing oneself at the coordinates of a feature point stored on the laid fabric, which is associated with a reference point and a connection point, and checking whether the feature points of the pattern of the laid fabric can indeed be found at these locations.

[0096] If not, then each time the nearest feature point is searched on the laid fabric, the difference between the stored theoretical position and the nearest actual position represents the offset to be corrected for the corresponding sheet in the layout.

[0097] In practical applications, the purpose of inspecting fabrics is to obtain actual characteristics, such as taking and analyzing images of a portion of the surface of the laid fabric around feature points of the pattern. See published EP0759708, which describes an example of inspecting and correcting a theoretical layout to take into account the actual characteristics of the fabric.

[0098] At the end of this inspection step, the theoretical layout of the sheet is modified to take into account the actual characteristics of the fabric laid on the cutting table. Therefore, the modification of the theoretical layout will generate the actual layout of the sheet on the laid fabric.

[0099] Figure 3 It shows the basis Figure 2 An example of an actual layout generated from the theoretical layout. In this example, by examining the laid fabric, it can be noticed that the material spacing p' is increased relative to the theoretical spacing p (i.e., p' is strictly greater than p).

[0100] The positions of sheet P-1 and sheet P-2 are both subject to absolute layout constraints. In order to ensure that their respective reference points O-1 and O-2 are located on the actual weft threads M3' (for sheet P-1) and M5' (for sheet P-2) of the laid fabric, their positions were modified.

[0101] The repositioning of reference point O-2 and the value of spacing P' make connection point L-2 located at a distance d' from parallel M11' in the actual layout, where d' represents 50% of the distance between actual parallels M11' and M12'.

[0102] For sheet material P-3, which is the daughter sheet material of the mother sheet material P-2, the actual layout is modified to retain the positioning constraints between points L-2 and O-3. This results in the reference point O-3 of the daughter sheet material P-3 being positioned between actual weft threads M3' and M4' at 50% of the actual weft spacing P' of the laid fabric (instead of 75% of the actual grid spacing p). This 50% of spacing P' corresponds to... Figure 3 The distance d' between the actual parallel M3' and the parallel M3'.

[0103] Similarly, for the sub-sheet material P-4, which serves as the mother sheet material P-3, the actual layout is modified to retain the same relative position with respect to the patterns of points L-3 and O-4. This results in the reference point O-4 of the sub-sheet material P-4 being positioned between actual weft threads M8' and M9' at 50% of the actual weft spacing P' between the laid fabric threads (instead of 90% of the actual grid spacing p). This 50% of spacing P' corresponds to... Figure 3 The distance e' between the actual parallel M8' and the parallel M8'.

[0104] Therefore, in Figure 2 The actual layout generated based on the theoretical layout shown has certain problems with the cutting of sheet materials, especially for overlapping sheet materials P-1 and P-3.

[0105] In fact, if a program for automatically cutting the sheets in the layout is started after the step of generating the actual layout (as is the convention in the background art), then sheets P-1 and P-3 will become defective sheets that need to be cut again.

[0106] The method provided by this invention is intended to automatically cut these defective sheets, regardless of the layout constraints associated with these sheets.

[0107] Generally, to achieve this, the method involves identifying defective pieces in the actual layout, which are those pieces that would contain defects once cut in the fabric and would require recutting (e.g., ...). Figure 3The actual layout shown includes sheet materials P-1 and P-3. Then, the layout constraints related to the defective sheet materials are adjusted according to the actual layout, so that each defective sheet material is automatically assigned to a new theoretical layout.

[0108] The term "defective sheet material" here refers to a piece of fabric that, once cut, will contain defects and needs to be cut again.

[0109] In a non-exhaustive manner, the following sheets can be considered defective sheets in the sense of this invention:

[0110] After the actual layout is generated, the sheet material is located on the defect of the already laid fabric;

[0111] After generating the actual layout, the sheet that overlaps with another sheet in the layout (e.g.) Figure 3 (The situations shown in P-1 and P-3 of the medium-sized sheet material);

[0112] After generating the actual layout, the sheet material is located in the area of ​​the already laid fabric where the deformation is large;

[0113] After the actual layout is generated, there are pieces of fabric that cannot be completely cut within the already laid-out fabric.

[0114] After generating the actual layout and cutting, sheet material with cutting defects;

[0115] After generating the actual layout, sheet material with geometric defects;

[0116] Sub-sheets associated with relative constraints or relative symmetrical constraints, relative to the defective master sheet that needs to be cut again.

[0117] The identification of defective sheets in the actual layout can be performed automatically before cutting begins (through analysis of overlapping sheets, detection of defects in the material, or inspection of excessively short material samples), or manually by the operator during sheet output and inspection of the sheets being cut. In this case, the operator should ideally have a graphical interface installed on the cutting machine to manually select defective sheets in the layout. More generally, this graphical interface should be able to display the layout during cutting and allow selection of sheets that need to be cut again.

[0118] The automatic allocation of defective sheet material to a new theoretical layout is achieved through an algorithm for repositioning the defective sheet material, which is implemented by a computer integrated into or separate from the cutting machine.

[0119] The following will be based on Figure 2 Taking the defective sheets P-1 and P-3 in the actual layout shown as examples, the implementation of this repositioning algorithm is explained.

[0120] The handling of defective sheet material P-1, which has absolute layout constraints and does not have sub-sheets, is relatively simple. In this case, the method provided by the present invention automatically assigns sheet material P-1 to the new theoretical layout by preserving the absolute constraints of the sheet material relative to the fabric pattern.

[0121] like Figure 4 As shown, this allocation method transfers the reference point O-1 from the sheet material P-1 to the new weft thread of the fabric (weft thread M18 in this implementation), so that the position of the fabric pattern on the sheet material is the same as its position in the actual layout.

[0122] In contrast, the processing of defective sheet material P-3 is more complex because it involves sheet material that is a daughter sheet material of mother sheet material P-2.

[0123] In order to find the same final position of sheet P-3 in the new theoretical layout, the position of its reference point O-3 relative to the fabric pattern must be the same as the position of the connection point L-2 of the mother sheet P-2 relative to the fabric pattern. In other words, the distance d' from the actual weft thread is equal to 50% of the spacing p' of the laid fabric.

[0124] Therefore, as Figure 5 As shown, allocating sheet P-3 to the new theoretical layout involves transferring the reference point O-3 of the sheet from the selected new weft (here, weft M15) by a distance d", which corresponds to the same percentage of the fabric spacing, i.e., 50% of the fabric spacing p.

[0125] In some cases, it may be necessary (or optional) to recut several sheets that are linked together by relative layout constraints.

[0126] Taking sheet materials P-3 and P-4, which are linked together by relative layout constraints, as an example (sheet material P-3 is the parent sheet material of sub-sheet material P-4), the two defective sheet materials can be automatically allocated to the new theoretical layout in the following way.

[0127] In actual layout (such as) Figure 3 As shown), place sheet P-3 so that its reference point O-3 is located between the actual weft lines M3' and M4', and the distance d' from the actual weft line M3' is equal to 50% of the spacing p' of the laid fabric.

[0128] As for sheet material P-4, it is placed in the actual layout (e.g., ...). Figure 3 As shown), its reference point O-4 is located between the actual weft lines M8' and M9', and the distance e from the actual weft line M8' is equal to 50% of the spacing p' of the laid fabric.

[0129] In the new theoretical framework (such as) Figure 6As shown, sheet material P-3 is placed to preserve its relative layout constraints.

[0130] Therefore, such as Figure 6 As shown, the position of the reference point O-3 of sheet material P-3 relative to the pattern of the laid fabric must be the same as the position of the connection point of the mother sheet material (sheet material P-2) relative to the pattern of the laid fabric. That is, the reference point O-3 is located between the new weft threads M15 and M16 and is d” away from the new weft thread M16. This distance corresponds to the same percentage of the fabric spacing, that is, 50% of the spacing p.

[0131] Even if the sheet does not have any defects that require recutting, the operator may still determine that it is necessary to recut sheet P-4 (the defective sub-sheet of the mother sheet P-3).

[0132] Therefore, such as Figure 6 As shown, the repositioning algorithm recalculates the position of the connection point L-3 of the mother sheet P-3 relative to the distance e” between the new weft lines M17 and M18. Then, the distance e” is reused to calculate the position of the reference point O-4 of the sheet P-4.

[0133] Therefore, regardless of the layout constraints of each defective sheet, it will be automatically assigned to generate a new theoretical layout that includes all defective sheets.

[0134] It is important to note that the repositioning algorithm operates in the same way for defective pieces associated with relative symmetry constraints: in the new theoretical layout, the relative symmetry constraints are transformed into absolute constraints, so that the position of the reference point of the sub-piece relative to the fabric pattern is consistent with its position in the actual layout.

[0135] It should also be noted that when the defective sheet is a parent sheet associated with at least one relative constraint or at least one relative symmetric constraint relative to one or more sub-sheets, the algorithm for repositioning the sheet on the new theoretical layout also includes automatically assigning one or more sub-sheets to the new theoretical layout.

[0136] Therefore, a new theoretical layout for the defective sheet can be cut on the cutting table in the region at the end of the actual layout, following the direction of fabric travel. It also involves a specific fabric sample derived from the same roll of fabric used to cut the actual layout, and located either after that roll or, depending on the cutting strategy, further downstream.

[0137] Alternatively, the new theoretical layout of the defective sheet can be incorporated into the subsequent layout according to the direction of fabric movement on the cutting table.

[0138] Of course, if one or more defective pieces are identified during the cutting of the new layout, the operation of automatically assigning these defective pieces to the new theoretical layout will be repeated.

Claims

1. A method for automatically cutting defective pieces in a patterned fabric, wherein the pattern is repeated at a certain interval, the interval being referred to as the pattern spacing, the method comprising: While adhering to the layout constraints associated with the sheet material to be cut (P-1, P-2, P-3, P-4), the theoretical layout of the sheet material to be cut (P-1, P-2, P-3, P-4) is generated on the theoretical representation of the fabric (T). At least one layer of the fabric is laid on the cutting table; Determine the actual characteristics of at least a portion of the laid fabric; Taking into account the actual characteristics of the fabric, the theoretical layout is modified to generate the actual layout of the sheet of the laid fabric; In the actual layout, defective pieces (P-1, P-2) are identified, which, once cut into the fabric, would contain defects and require recutting; and By adjusting the layout constraints related to the defective sheet according to the actual layout, each defective sheet is automatically assigned to a new theoretical layout.

2. The method of claim 1, wherein each of the pieces to be cut (P-1, P-2, P-3, P-4) is associated with a reference point (O-1, O-2, O-3, O-4) and a layout constraint on the fabric, the layout constraint being selected from the following constraints: a) Absolute constraint, where, The position of the reference point of the sheet relative to the fabric pattern is determined, so that the fabric pattern appears at the desired position on the sheet; b) Relative constraint, wherein the position of a reference point of a sheet called a sub-sheet relative to the connection point (L-2, L-3) of another sheet called a mother sheet is determined, such that the position of the reference point of the sub-sheet relative to the fabric pattern is the same as the position of the connection point of the mother sheet. c) A relative symmetry constraint, wherein the position of a reference point of a sheet called a sub-sheet relative to the connection point of another sheet called a mother sheet is determined, such that the position of the reference point of the sub-sheet relative to the fabric pattern and the position of the connection point of the mother sheet are pattern-symmetrical; and d) Free constraint, wherein the position of the reference point of the sheet relative to the fabric pattern is free.

3. The method according to claim 2, wherein, When the defective sheet is a sheet associated with an absolute constraint, the automatic allocation of each defective sheet to a new theoretical layout includes: retaining the absolute constraint relative to the fabric pattern in the new theoretical layout.

4. The method according to claim 2, wherein, When the defective sheet is a sub-sheet that has been assigned relative or relative symmetrical constraints to the mother sheet that does not need to be cut again, the step of automatically assigning each defective sheet to a new theoretical layout includes: converting the relative constraints into absolute constraints in the new theoretical layout so that the position of the reference point of the sub-sheet relative to the fabric pattern and the position of the reference point of the sub-sheet in the actual layout are consistent.

5. The method according to claim 2, wherein, When the defective sheet is a parent sheet associated with at least one of the relative constraints or at least one of the relative symmetry constraints relative to one or more sub-sheets, the automatic allocation of each of the defective sheets to a new theoretical layout further includes: automatically allocating the one or more sub-sheets to the new theoretical layout.

6. The method according to claim 2, wherein, When the defective sheet is a sheet associated with the free constraint, the automatic assignment of each defective sheet to a new theoretical layout includes: in the new theoretical layout, there is no positional constraint of the reference point of the sheet relative to the fabric pattern.

7. The method according to any one of claims 1 to 6, wherein, In the end region of the actual layout, the new theoretical layout of the defective sheet is calculated and cut according to the direction of the fabric's movement on the cutting table.

8. The method according to any one of claims 1 to 6, wherein, The new theoretical layout of the defective sheet is incorporated into the subsequent layout according to the direction of the fabric's movement on the cutting table.

9. The method according to any one of claims 2 to 6, wherein, The defective sheet material is: After the actual layout is generated, the sheet material located on the defect of the already laid fabric; or After the actual layout is generated, the sheet material overlapping with another sheet material in the layout; or After the actual layout is generated, the sheet material located on the area where the laid fabric has significant deformation; or After the actual layout is generated, there are pieces of fabric that cannot be completely cut within the laid fabric; or After the actual layout is generated and cut, the sheet material has cutting defects; or After generating the actual layout, sheet material with geometric defects; or The sub-sheet material associated with the relative constraint or the relative symmetry constraint, relative to the defective master sheet material that needs to be cut again.

10. The method according to any one of claims 1 to 6, wherein, The defective sheet material is not cut within the laid fabric.

11. A system for automatically cutting defective pieces in a patterned fabric, the pattern being repeated at a certain interval, the interval being referred to as the pattern spacing, the system comprising: A tool for generating a theoretical layout of the sheet to be cut (P-1, P-2, P-3, P-4) on the theoretical representation of the fabric (T) while adhering to the layout constraints associated with the sheet to be cut (P-1, P-2, P-3, P-4); A cutting table on which at least one layer of the fabric can be laid; A tool used to determine the actual characteristics of at least a portion of the laid fabric; A tool for modifying the theoretical layout to generate an actual layout of the laid-up fabric sheet while taking into account the actual characteristics of the fabric; Tools for identifying defective pieces (P-1, P-2) in the actual layout, which would contain defects and need to be cut again once cut in the fabric; as well as A tool for adjusting the layout constraints associated with the defective sheet according to the actual layout, thereby automatically assigning each defective sheet to a new theoretical layout.

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