Method for controlling the position of a seam contour relative to the structure of a sewing material - Patent Application 20070122997

Abstract

The present invention relates to a method for controlling the position of a seam contour and an apparatus for carrying out the method, in which the position control of the seam contour relative to the structure of the sewing material is based on comparison data between the structure of the reference sewing material and the structure of the working sewing material.

Description

[Technical Field]

[0001] This patent application claims priority from German patent application DE 10 2018 207 931.5, the content of which is incorporated herein by reference.

[0002] The present invention relates to a method for controlling the position of a seam contour relative to a structure of sewing material, and to a sewing device for carrying out such a method. [Background technology]

[0003] From US Pat. No. 5,623,299, ... and US Pat. No. 5,623,299, sewing devices are known which are provided with a camera for recording the sewing material, and the seam contour to be sewn is determined on the basis of the recorded image data.

[0004] In particular, in the case of sewing materials where the location of a structure is important (e.g., leather with a perforation pattern), it has been shown that the application of the structure (e.g., the perforation pattern) cannot be easily positioned on the sewing material in a reproducible manner due to the non-uniform properties of the sewing material. Even with devices and methods known from the state of the art, reproducible sewing of seams to a structure is not possible, at least when there is a high requirement for high precision regarding the seam location relative to the structure.

[0005] U.S. Patent No. 5,629,663 discloses a method for quilting along the contour of a pattern applied to a flat elastic fabric and an apparatus for carrying out the method. U.S. Patent No. 6,429,663 discloses a method and apparatus for feeding sheet material. U.S. Patent No. 6,429,663 discloses a method for compensating for pattern distortion of flat work material spread on a conveying surface. U.S. Patent No. 6,429,663 discloses an apparatus for edge detection and sewing. U.S. Patent No. 6,429,663 discloses a sewing machine and a sewing machine control program. U.S. Patent No. 6,429,663 discloses an apparatus for correcting the position of sewing material. U.S. Patent No. 6,429,663 discloses a method for positioning and feeding sewing material. U.S. Patent No. 6,429,663 discloses a shape recognition apparatus and a sewing machine. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] EP 1 997 945 A1 [Patent Document 2] EP 0 971 061 A1 [Patent Document 3] US 2012 / 022602 A1 [Patent Document 4] GB 2 240 193 A1 [Patent Document 5] DE 35 35 644 C2 [Patent Document 6] DE 689 07 167 T2 [Patent Document 7] DE 102 36 581 A1 [Patent Document 8] US 5,205,232 [Patent Document 9] US 2009 / 0188414 A1 [Patent Document 10] DE 42 03 558 A1 [Patent Document 11] DE 42 05 070 A1 [Patent Document 12] DE 10 2015 116 112 A1 Summary of the Invention [Problem to be solved by the invention]

[0007] One object of the present invention is to provide a method that allows for sufficiently accurate position control of the seam contour relative to the structure of the sewing material, even with high precision requirements. This object is achieved by the features of claim 1. [Means for solving the problem]

[0008] The present invention is based on the recognition that the sewing program is adapted so that position control of the stitch contour relative to the structure of the sewing material is performed based on data obtained by comparing the structures of the reference sewing material and the working sewing material.

[0009] Using a method for controlling the position of a seam contour relative to a structure of sewing material, the reference position of the structure of sewing material has such a structure, Strictly optimized tolerances, not used for sewing The reference sewing material is first recorded based on the reference position. A reference structure data set is generated based on the recorded reference position using the recorded structure reference position. After the reference structure data set is generated, the working sewing material is sewn with a sewing program. Here, the sewing program is loaded or selected before sewing the working sewing material, and the following steps for preparing the sewing program are performed: - recording a work position in the sewing material structure of the working sewing material, which corresponds to the sewing material structure of the reference sewing material; - generating a work structure data set based on the recorded structure work positions; - comparing the working position with the reference position by comparing the reference structure dataset with the working structure dataset; - adapting parameter data of the sewing program based on the deviation between the reference structure data set and the working structure data set recorded during comparison; is performed before sewing the work sewing material.

[0010] The working sewing material is then sewn with the adapted sewing program.

[0011] The reference sewing material is not the same as the working sewing material, and therefore, one reference sewing material and each of the other working sewing materials are different sewing materials.

[0012] Examples of structures in the sewing material are perforations in the sewing material, or patterns or color patterns in the sewing material, especially irregular patterns. Advantageously, the positions of several consecutive perforations and / or the length or direction of a series of perforations or the angle between two parts of a series of perforations can be recorded and processed. The course of the pattern or color pattern in the sewing material can be recorded and the seam contour can be adapted thereto.

[0013] It is recognized that a control method that compares an initially generated reference structure data set with a working structure data set of the sewing material to be sewn, generated based on the recorded structure working positions, makes the data processing work of the corresponding position control method manageable, even with the high accuracy and high speed requirements necessary for serial production. The working structure data set can be generated in a manner that is adapted to the structure present in the sewing material, thereby taking into account the characteristics of the structure, for example, the perforation arrangement and pattern details of the existing sewing material.

[0014] Claim 1 The method described in allows further improvement of the adaptation of the sewing program, further improvement of the position control of the seam contour, and optimization of the seam pattern. Exactly one deviation in the deviation categories "Displacement along the first sewing coordinate", "Displacement along the second sewing coordinate", "Size difference of the structure-data set", "Angular deviation" or "Size difference of the spread of the structure-data set" can be used. Alternatively, two or more of these deviation categories can be used, for example a combination of two, three, four or all of these deviation categories.

[0015] Claim 1The structure-dataset deviations described in have proven successful in practice for structures typically present in sewing materials. Taking into account displacement deviations along at least one stitching coordinate ensures that there are no unwanted offsets of the stitch contour when comparing the reference sewing material with the current working sewing material. Taking into account size differences ensures that, for example, different replication scales do not have an undesired effect on position control when recording the reference sewing material on the one hand and the working sewing material on the other. The same applies when taking into account angle deviations or size differences between the start and end points of the data sets.

[0016] Claim 2 The insertion of the sewing material into the sewing material frame as described in ensures a reproducible positioning of the sewing material.

[0017] A further object of the invention is to provide a sewing device for carrying out this method.

[0018] The challenge is, Claim 3 This is solved by the characteristics of

[0019] The camera system can ensure that position-critical sewing material with the structure is recorded in the correct position, and the seam can be sewn along a predetermined path relative to the structure of the sewing material. The camera system can be a stereo camera system. The camera system can be designed to check deviation categories in real time during the sewing process.

[0020] Exemplary embodiments are explained in more detail by the figures, in which: [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a sewing device shown with individual parts omitted. [Figure 2] 2 is a view of the sewing device shown in FIG. 1 taken along line II-II. [Figure 3] 1 is a partial view of a working sewing material having a working structure. [Figure 4] 1 is a flowchart of a method for controlling the position of a stitch profile. DETAILED DESCRIPTION OF THE INVENTION

[0022] 1 and 2 show diagrammatically a sewing machine 1. Such a sewing machine 1 may for example be a CNC sewing machine, in particular the Applicant's CNC sewing machine KL110.

[0023] For ease of orientation, a Cartesian xyz coordinate system is shown in Figures 1-3. The x-axis is perpendicular to and passes through the drawing plane of Figure 1. The y-direction extends to the left in Figure 1, and the z-direction extends upward in Figure 1.

[0024] As shown in Figure 1, the sewing device 1 comprises a sewing machine sewing head 2. The sewing machine includes, among other things, a needle bar 3 with a sewing needle 4, and the sewing head 2 is mounted so as to be rotatable about the z-axis. A gripper 5, shown diagrammatically, is arranged coaxially and opposite the z-axis.

[0025] Between the needle 4 and the gripper 5 is a sewing material 6 having a structure 7. The sewing material 6 is clamped to a sewing material frame 8. The sewing material frame 8 is movable in the xy plane relative to the sewing head 2. The rotation of the sewing head 2 and the mobility of the sewing material frame 8 in the xy plane provide three degrees of freedom, allowing stitch contours to be achieved in all sewing directions on the xy plane.

[0026] The sewing material 6 can be a reference material or a working sewing material. The reference sewing material is a sewing material with a structure that is applied to a strictly tolerant, optimized material. The sewing program is created based on the reference sewing material. This is described in more detail below with reference to FIG. 4. The working sewing material is a sewing material to be sewn, with a structure that corresponds to the structure of the reference material. Irregularities may exist. Such irregularities are typically caused by the application of structures such as perforations. This occurs because the material is distorted during the application of the structure, for example, by stretching and / or compression. This results in a change in the position of the structure of the working sewing material compared to the structure of the reference material. Irregularities (unevenness) may also be the result of a change in the position of the working sewing material in the sewing material frame compared to the reference material in the sewing material frame. The presence of irregularities requires an adaptation of the sewing program. This is also described in more detail below with reference to FIG. 4.

[0027] Displaced along the y-axis from the sewing needle 4 is a camera system 9 which is in signal connection 10 with a control unit 12 of the sewing device 1 (in particular a CNC control unit, which is located in a computer unit 11). In particular, the camera system 9 can have two cameras, which are not shown in detail. The camera system 9 can be designed as a stereo camera system or as a smart camera.

[0028] The computer unit 11 is provided with a memory element 13, in particular a RAM memory, in which at least one sewing program is stored. Furthermore, the computer unit 11 or the camera system 9 itself is provided with evaluation software 14 for evaluating images, in particular the generated reference images and working images, and for determining reference structure data sets and working structure data sets. The evaluation software 14 exchanges parameters and data with the sewing program, which is processed when sewing a seam with the sewing device 1. Communication between the camera system 9 and the control unit 12 can take place, for example, via the USB (Universal Serial Bus) standard, by reading and writing files on a data carrier, or via a TCP (Transmission Control Protocol) connection.

[0029] The control unit 12 informs the evaluation software 14 of which sewing program to adapt. The camera system 9 can inform the control unit 12 of readiness, error, success, etc. of the operation. Based on this, the control unit 12 can start the evaluation of the camera system 9. After a successful evaluation, the camera system 9 transmits the adaptation parameters of the selected sewing program to the control unit 12 by manipulating the parameter values, for example, to compensate for displacement of individual points due to stretching, expansion, and / or compression of the sewing material 6. This procedure provides automatic adaptation of the parameter values ​​for adapting the sewing program. The adaptation is performed for each sewing process based on the evaluation of the camera system 9. Before each sewing process, the camera system 9 records an image area 15 of the unsewn material 6, from which the image to be evaluated is generated. Depending on the desired seam contour for the structure 7, the image area 15 can include the entire sewing material 6 or at least a portion of the sewing material 6. Thus, an image of the entire sewing material 6 or an image of a partial area of ​​the sewing material 6 can be generated.

[0030] FIG. 3 shows a partial view of unsewn working sewing material 16 stretched over sewing material frame 8 and having perforation holes 17 in the form of spaced squares 18 on their upper surfaces. Between the squares 18 on the upper surface are intermediate spaces 19 in which the seam outlines are located. The seam outlines are centered as much as possible between the squares 18 on the upper surface. As shown in FIG. 3, the squares 18 on the upper surface aligned along the y-axis are displaced along the x-axis. At the same time, the squares 18 on the upper surface aligned along the x-axis are also displaced along the y-axis.

[0031] Prior to sewing, the camera system 9 creates an image of the work sewing material 16. This image becomes the work image. From this, a work structure data set is generated and compared with a reference structure data set generated from a previously created reference image (not shown). In this case, the entire sewing material, i.e., both the entire reference sewing material and the entire work sewing material, are recorded to generate the reference image and the corresponding work image.

[0032] A method for controlling the position of the seam contour relative to the structure 7 of the sewing material 6 will now be described with reference to FIG.

[0033] First, in step S1, the reference position of the sewing material structure has such a structure: Strictly optimized tolerances, not used for sewing The recording is based on a reference sewing material. For this purpose, the camera system 9 first generates a reference image of the reference sewing material. In this case, the entire reference sewing material is recorded. The reference image is then loaded into the camera system 9, and recognition (identification) of sewing material structures 17, such as perforations, begins.

[0034] To record the structure reference positions, measurement lines are generated in the camera system 9. These measurement lines are generated in the reference image by marking the individual perforation holes. The measurement lines can be used to record the structure. This is done in particular by recording the start and end points in the x-direction, the start and end points in the y-direction, and / or the angle of the measurement line. Overall, a total of 99 measurement lines (as an example) can be generated, each of which can be specified with different individual measurements (i.e., parameters).

[0035] Then, in step S2, a reference structure data set is generated based on the recorded structure reference positions.

[0036] For this purpose, the individual measurement lines are stored with reference to the sewing program in the form of a list of pixel or scaled coordinates, which makes it possible to find the measurement lines in the image to be evaluated and to evaluate the positional changes of the individual perforation holes relative to this reference. For each parameter of each measurement line, an identifier is defined which is used for communication with the control unit 12.

[0037] Thereafter, the steps for preparing a sewing program begin in step S3.

[0038] In step S4, the control unit 12 notifies the camera system 9 of which sewing program to modify. The camera system 9 reports the next status, specifically, operation preparation, evaluation, success, and error, to the control unit 12. Next, the control unit 12 notifies the camera system 9 of the next status, specifically, the start of camera evaluation.

[0039] In the next step S5, the work position of the material structure 18 of the work sewing material 16, which corresponds to the sewing material structure of the reference material, is recorded. For this purpose, the camera system 9 generates an image of the unsewn work sewing material 16. This image becomes the work image.

[0040] To record the work position, a measurement line is generated in the camera system 9. For this purpose, the work image is first loaded into the camera system 9, and recognition of the perforation holes 17 in the work sewing material 16 begins. Subsequently, measurement lines can be automatically generated in the work image by marking the individual perforation holes 17. In this way, measurement line data from the recorded reference image can be used. The generation of the measurement line can be performed in a similar manner to step S1.

[0041] Subsequently, in step S6, a work structure data set is generated based on the recorded structure work positions, in a manner similar to step S2, based on a reference structure data set stored for the corresponding sewing program.

[0042] Subsequently, in step S7, the working position is compared with the reference position by comparing the reference structure data set with the working structure data set, and the comparison results in corresponding deviation parameters, on the basis of which the sewing program can be adapted.

[0043] Adaptation of the parameter data of the sewing program based on the deviations between the reference structure data set and the working structure data set recorded during the comparison is carried out in step S8.

[0044] The deviations between the reference structural data set and the working structural data set are considered from at least one deviation category of the following group: - displacement of the working sewing material relative to the reference material along the sewing coordinates, - the displacement of the working sewing material relative to the reference sewing material along the second sewing coordinate, perpendicular to the first sewing coordinate, - a size difference of the working structure data set relative to the reference structure data set along at least one of those stitching coordinates; - of the working structure dataset relative to the reference structure dataset along the stitching coordinates along the line connecting the start and end points of each dataset. spread Angular deviation of, and - of the working structure dataset relative to the reference structure dataset along the stitching coordinates along the line connecting the start and end points of each dataset. spread Size difference.

[0045] The adaptation of the sewing program is performed via the camera system 9. In doing so, the camera system 9 modifies the selected sewing program by manipulating parameter values ​​of the sewing program. This is done based on at least one of the deviation categories or a combination of at least two of the deviation categories. For example, the sewing program is stored in the computer unit 11, which is used jointly by the camera system 9 and the control unit 12. Alternatively, the camera system 9 can directly transmit parameter values ​​to the control unit 12, which then affect the currently selected sewing program. This procedure allows each sewing process to be modified based on the camera evaluation.

[0046] For this purpose, the parameters to be used must be entered into the sewing program using assignments. Depending on the evaluation of the results of initial measurements using material samples with different tolerances, the defined parameters can be calculated in the sewing program. Standard commands made available by the control unit 12 are used for this purpose. The commands can replace the entire sewing program and / or individual seam contours and / or individual start and end points of a seam. Furthermore, the commands can stretch or compress the sewing material. Furthermore, commands can be used to compensate for angular errors. The corresponding correction commands are entered into the sewing program in such a way that they make changes to the reference sewing program.

[0047] Subsequently, in step S9, the work sewing material 16 is sewn with the adapted sewing program, and the stitching is performed along a precisely predetermined path relative to the structure 18 of the work sewing material 16. [Explanation of symbols]

[0048] 1 Sewing device 2 sewing heads 3 needle bar 4 sewing needles 5 Gripper 6 Sewing materials 7. Structure 8 Sewing material frames 9 Camera System 10 Signal Connections 11 Computer Unit 12 Control Unit 13 Memory Elements 14 Evaluation Software 15 Image Area 16 Working Sewing Materials 17 Sewing material structure (perforation holes) 18 Material structure (square) 19 Intermediate Space

Claims

1. 1. A method for controlling the position of a seam contour relative to a structure of sewing material, comprising: - recording the reference position of said sewing material structure using a reference sewing material that has such a structure, optimized to a strict tolerance, and that is not used for sewing; - generating a reference structure data set based on the recorded structure reference positions; - after generating said reference structure data set, sewing a working sewing material with a sewing program, - before the step of sewing said working sewing material, the following steps for preparing said sewing program: - recording the working positions of the sewing material structures of the working sewing material that correspond to the sewing material structures of the reference sewing material; generating a working structure data set based on the recorded structure working positions; - comparing said working position with said reference position by comparing said reference structure data set with said working structure data set; - adapting parameter data of the sewing program based on the deviations between the reference structure data set and the working structure data set recorded during the comparison; - sewing the work sewing material with the adapted sewing program; A method comprising: At least one deviation between the reference structure dataset and the working structure dataset is selected from the following group: - the displacement of the working sewing material relative to the reference sewing material along a first sewing coordinate; - the displacement of the working sewing material relative to the reference sewing material along a second sewing coordinate perpendicular to the first sewing coordinate; - the size difference of said working structure data set relative to said reference structure data set along at least one of said stitching coordinates; the angular deviation of the extent of the working structure data set relative to the reference structure data set along the stitching coordinates along the line connecting the start and end points of each of the data sets; and the size difference of the extent of the working structure data set relative to the reference structure data set along the stitching coordinates along the line connecting the start and end points of each of the data sets; 2. A method comprising:

2. The sewing material is inserted into a sewing material frame; 2. The method of claim 1, wherein the reference position and the working position are recorded with the sewing material inserted.

3. A sewing device (1) for carrying out the method according to claim 1 or 2, comprising: - A sewing machine, - a sewing material frame (8), - a camera system (9), - a programmable control unit (12) in signal communication with said sewing machine and said camera system.

Images