JP2023070654A - Method for producing sewing data set as basis of sewing program for sewing seam profile onto sewn material having sewn material structure - Google Patents

Abstract

To provide a method for producing a sewing data set of a sewing program for sewing a seam profile onto a sewn material having a sewn material structure.SOLUTION: Distortion of an image field is detected, a camera is calibrated, and a calibrated grid is recorded. A sewn material 26 having a sewn material structure 27 is fixed onto a sewn material holder 25. The sewn material holder has four position markers 21 to 24, which can be detected after fixed. Actual images of the sewn material and the sewn material holder having the position markers are recorded. The actual image is overlapped by a target image indicating a target position of the sewn material structure in an xy coordinate system of a sewing system and a target seam profile overlap. A sewing data set is produced on the basis of a deviation between the actual images and the target image. Deviation detection is performed on the basis of camera calibration information obtained at the calibration time and absolute coordinates of the position markers in the xy coordinate system. Regarding positioning of the seam profile with respect to the sewn material structure, a sewing program production process satisfying requirements can be obtained.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for creating a sewing data set that forms the basis of a sewing program for sewing seam contours on a sewing material having a sewing material structure. Furthermore, the invention relates to a material holder for carrying out a method of this kind and a sewing system comprising at least one material holder of this kind for carrying out a method of this kind.

A sewing system for sewing a seam profile in a sewing material is known from US Pat. A method for controlling the position of the seam contour relative to the structure of the sewing material is known from US Pat. US Pat. No. 5,300,003 discloses a method of stitching along the contours of a pattern applied to flat elastic fabrics and an apparatus for carrying out the method. US Pat. No. 5,300,009 discloses a method for generating an image showing the embroidery surface of an embroidery frame to enable computerized machine embroidery. U.S. Pat. No. 6,200,000 discloses a sewing machine system and an embroidery frame. U.S. Pat. Nos. 5,300,000, 5,000,000, 5,000,000 and 5,000,003 disclose computer readable media storing sewing machines and sewing machine control programs. US Pat. No. 5,300,001 discloses a sewing machine. Japanese Patent Application Publication No. 2004-101002 discloses a device for recognizing shapes, and Japanese Patent Application Publication No. 2004-0000002 discloses a sewing machine. US Pat. No. 5,300,009 discloses a method and system for automatic calibration of needle position.

EP 3 088 587 B1 WO 2019/219 296 A1 DE 35 35 664 C2 DE 10 2018 209 000 A1 US 2014/0230706 A1 US 2011/0048300 A1 EP 2 357 272 A1 US 8,738,171 B2 US 8,061,286 B2 US 11,268,222 B2 DE 10 2015 116 112 A1 DE 20 20219 101 858 U1 US 2019/0340784 A1

For example, in the automotive sector, very high demands are placed on the positional accuracy of the seam contour on the sewn material structure. SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for creating a sewing data set that forms the basis of a sewing program for sewing seam contours on a sewing material having a sewing material structure, which comprises stitch contours for sewing material structures. Regarding positioning, it satisfies the best position requirements.

This object is achieved according to the invention by a method having the features indicated in claim 1 .

According to the invention, by using at least four position markers on the sewing material holder, on which the sewing material is held in sequence, imaging errors of the camera used in the method can be detected very accurately. is recognized. In particular, distortion can be detected very accurately, in particular trapezoidal distortion can be detected accurately. In particular, distortion errors can be taken into account that cannot be detected by the camera's native calibration or can only be detected with great effort. Sewing programs created based on images captured using four position markers and deviations of the processed target/actual images provide an extremely accurate positional accuracy of the seam shape relative to the structure of the sewn material. Accurate sewing is guaranteed.

A method of creating a sewing data set includes initial calibration of the camera using a calibration grid, and target positions and target seam contours of the sewing material structure in the sewing system coordinate system for the actual image of the sewing material and the sewing material holder with position markers. A comparison of target images shown in FIG. Such a combination ensures that the resulting sewing data set is accurate.

Both method steps "initial calibration" and "comparison of actual and target images" contribute to the accuracy of such a sewing data set.

The method according to the invention can in particular be used for positionally accurate stitching on a CNC sewing machine to a sewing material structure, even with sewing material cuts that deviate from one piece of sewing material to the next. . When applying the method, the exact dimensional accuracy of the corresponding sewing material cut is not critical.

Examples of sewn materials having sewn material structures include car seats, dashboards, trouser pockets, flaps, belts, handbags, and the like.

The sewn material structure may be perforations.

A precise four position marker according to claim 2 has proven to be sufficient to meet even stringent positioning requirements.

The collection of additional sewing material holder-specific information according to claim 3 can take into account the sewing material holder-specific correction values to which the sewing material holder-specific information corresponds, so that individual avoids the need to calibrate the sewing material holder of the

The preparation step according to claim 4 provides one possibility of how the coordinates of the position markers are acquired absolutely before the sewing program is created.

The advantages of the sewing material holder according to claims 5 and 6 correspond to those already explained above with respect to the method. This also applies accordingly to the sewing material holder according to claim 7 .

The QR code (registered trademark) according to claim 8 has proven to be a robust information carrier.

The advantages of the sewing system according to claim 9 correspond to those already explained above with respect to the method and the sewing material holder.

A set of sewing material holders according to claim 10 makes it possible to achieve a high throughput of sewing material during the sewing operation by the sewing system.

Below, examples of embodiments of the invention will be described in more detail with reference to the drawings.

Fig. 1 schematically shows a sewing system in top view, showing mainly working areas of different sewing materials during processing by the sewing system; Fig. 10 is a top view of a variant of the sewing material holder, on which the sewing material is fixed, before sewing a seam contour that fits the sewing material structure of the sewing material; FIG. 3 is a representation similar to FIG. 2 showing a sewing material holder holding sewing material with sewn seam contours; FIG. 4 is an enlarged cut-out view of the sewing material of FIG. 3;

The sewing system 1 comprises a sewing machine 2 for sewing seam profiles on a sewing material 3 having a sewing material construction not shown in FIG. The sewing machine 2 sews the sewing material 3 in a stitch forming area 4 by forming at least one seam 5 . The sewing material conveying installation 8 serves to convey the sewing material 3 from the supply area 6 to the stitch forming area 4 and to convey the sewing material 3 from the stitch forming area 4 to the storage area 7 . The sewing material conveying installation 8 conveys a holding frame 9 to which the sewing material 3 is fixed. The holding frame 9 is hereinafter also referred to as a sewing material holder. The holding frame 9 is guided and held by linear guides 10 of the sewing material transport installation 8 . A linear guide 10 extends from the supply area 6 via the stitch forming area 4 to the storage area 7 . These three areas 4 , 6 and 7 form a sewing transport area 11 .

A sewing transport drive 12 is used to move the holding frame 9 between the supply area 6 (see momentary position in the figure) and the storage area 7 . The latter includes an xy coordinate table which is designed in a manner known per se and which can be driven in a controlled manner in order to generate the contour of the seam 5 during sewing. The corresponding xy coordinate system is shown in FIG.

The sewing system 1 also has a sewing material supply and transport installation 13 . The latter transports the sewing material 3 from the sewing material supply stack area 14 to the supply area 6 of the sewing material transport installation 8, and transports the sewing material 3 from the storage area 7 of the sewing material transport installation 8 to the sewing material storage stack area 15. play a role. In this way, the sewing material supply and transport installation 13 transports the sewing material 3 to the feed supply transport area 16 on the one hand and to the storage supply transport area 17 on the other hand. The feed supply conveying area 16 includes the sewing material supply stack area 14 and the supply area 6 . Storage supply transport area 17 includes storage area 7 and sewing material storage stack area 15 .

The sewing material supply and transport installation 13 is designed as a gripping robot and includes a robot base unit 18 which is connected via a hinge connection 19 to a sewing material gripper 20 for actuating it. In the exemplary embodiment shown, one and the same gripping robot 13 is designed to transport the sewing material 3 in the feed-supply conveying area 16 on the one hand and in the storage-supply conveying area 17 on the other hand. The path of the sewing material between the sewing material supply stack area 14 and the sewing material storage stack area 15 is indicated by arrows in FIG.

The sewing material holder 9 has a total of four position markers 21, 22, 23, 24, which are attached to the sewing material holder 9 at a distance from each other. That is, each occupying a position on the sewing material holder 9 with a different set of xy coordinates (ie individual sets of x and y coordinates).

FIG. 2 shows another version of the sewing material holder 25 to which the sewing material is applied and secured with the sewing material holder 25, using the example of a seat surface of a passenger car. The sewing material has sewing material structures 27 in the form of perforations (perforations) introduced into the sewing material 26 in a diamond pattern. Between the diamonds 28 of this perforated diamond pattern are unperforated sewing material areas 29 along which seams 29 are applied in very precise locations in the form of seam contours. This is shown in more detail in FIGS.

The sewing material holder 25 also comprises four position markers 21-24, which correspond in terms of their function to the position markers of the embodiment according to FIG.

The sewing material holder 25 has a rectangular (rectangular) basic shape.

The four position markers 21-24 are firmly attached to the four corners of the sewing material holder 25, and their position relative to the sewing material holder 25 is fixed after the position markers 21-24 are attached. Each of the position markers 21 - 24 is designed in a crosshair manner with a precisely defined position marker reference center point 30 . This crosshair may be formed by circumferentially alternating light and dark quadrants centered on a central point 30 .

The position markers 21 to 24 are attached to the sewing material holder 9 or 25 so that the position markers are visible in a top view after the respective sewing material 3 or 26 has been secured to the sewing material holder 9 or 25 .

The sewing material holder 25 also carries an information carrier 31 with sewing material holder-specific information regarding the x and y coordinates of the four position markers 21-24. The information on the information carrier 31 ensures that the individual contributions of the coordinates of the four position markers 21-24 are precisely defined in the xy coordinate system of the sewing system 1 for the sewing material holder 9 or 25 guided along the linear guide 10. can be determined absolutely. Such individual contributions may result from the individual manufacture of each sewing material holder 25 and/or each position marker 21-24. The position of the position markers 21-24 on the sewing material holder 9 or 25 can be determined absolutely at a predetermined position of the sewing material holder guided by the linear guide 10, and these position markers 21-24 can be stored on the information carrier 31 .

The information carrier 31 can be designed as a QR code®. The information carrier 31 can also be an RFID chip.

In preparation for sewing the sewing pattern according to FIGS. 3 and 4, first a sewing data set is created for executing a sewing program for sewing this sewing contour onto the sewing material 3 or 26 . In this process, the camera 32 (see FIG. 1) of sewing system 1 is first calibrated. This is done by detecting the distortion of the camera 32 on the image field lying in the image plane using recording a calibration grid with the camera 32 in the image field. For example, a checkerboard structure in which the size of the individual panels is precisely known can be used as a calibration grid, this checkerboard structure detecting the sewing material 3 or 26 on the respective sewing material holder. It is also used to detect the edge regions of the image field of the camera 32 that are required for scanning.

A piece of sewing material 3 or 26 is secured to a sewing material holder 9 or 25 during the sewing program creation process. The position markers 21-24 can still be detected by the camera 32 after this fixation. The x- and y-coordinates of each of the position markers 21 - 24 are known as a result of preparatory measurements and/or by reading out the information carrier 31 . In order to obtain the x- and y-coordinates of the position markers 21-24, these are thus mounted on the sewing material holder 9 or 25 as part of the preparatory steps in the guiding position of the linear guide 10, after which It can be determined by measurements in the xy coordinate system of the sewing system 1 .

As part of the process, the camera 32 then records a real image of the sewing material holder 9 or 26 with the sewing material 3 or 25 and the position markers 21-24. This real image is then superimposed on a target image showing the target position of the sewing material structure 27 and the target seam contour of the seam 29 in the xy coordinate system of the sewing system 1 . A deviation between the real image and the target image is then detected. Here, the camera calibration information obtained in the calibration step described above and, on the other hand, the x, y coordinates of the position markers 21-24, whose absolute values are known in the xy coordinate system of the sewing system 1, are combined with this Included in deviation detection.

By using the four position markers 21-24, camera distortion errors can be detected very accurately and taken into account when comparing the actual and target images. In particular, trapezoidal distortion can be reliably removed. Keystone correction (trapezoidal distortion correction) can be used here.

The sewing system 1 can have a set of sewing material holders 9 or 25 in which the sewing material 3 or 26 is successively loaded and processed during sewing.

The sewing system 1 can then use the created sewing program to apply the stitch contours to the correct positions of the sewing material 3 or 26 according to the corrected target pattern. This is shown as an example of sewing material 26 in FIGS.

A seam 29 runs exactly centrally along the spacing between the diamonds 28 of the perforated diamond structure.

The positional accuracy of this seam profile relative to the centerline along the spacing between the rhombuses 28 can be better than 0.1 mm, in particular better than 0.05 mm. Deviations from the ideal central course are in any event undetectable even by a stern observer and are much smaller than the thickness of the thread used to make the seam 29 .

REFERENCE SIGNS LIST 1 sewing system 2 sewing machine 3, 26 sewing material 4 stitch forming area 5 seams 6 supply area 7 storage area 8 sewing material transport installation 9, 25 sewing material holder (9 holding frame)
10 linear guide 11 sewing conveying area 12 sewing conveying drive device 13 sewing material supply conveying installation 14 sewing material supply stack area 15 sewing material storage stack area 16 feed supply conveying area 17 storage supply conveying area 18 robot base unit 19 hinge connection 20 sewing material Grippers 21, 22, 23, 24 Position markers 27 Sewing material structure 28 Diamonds 29 Seams (or unperforated areas of sewing material)
30 position marker reference center point 31 information carrier 32 camera

Claims (10)

A method for creating a sewing data set that forms the basis of a sewing program for sewing seam contours on a sewing material (3; 26) having a sewing material structure (27), comprising:
calibrating the camera (32) by detecting distortions on the image field present in the image plane (xy) using a recording of a calibration grid in the image field of the camera (32);
Securing a piece of sewing material (3; 26) having a sewing material structure (27) in a sewing material holder (9; 25) having at least four position markers (21-24); , said at least four position markers (21-24) are detectable by said camera (32), and the x and y coordinates of each position marker (21-24) are in the xy coordinate system of the sewing system (1) a step that is absolutely known;
recording a real image of the sewing material (3; 26) and the sewing material holder (9; 25) with the position markers (21-24);
superimposing a target image showing target positions and target seam contours of the sewing material structure in the xy coordinate system of the sewing system (1) on the actual image;
creating a sewing data set as a basis for a sewing program based on the detected deviations between the actual image and the target image, comprising:
The detection of said deviation is based on, on the one hand, camera calibration information obtained during camera calibration and, on the other hand, the x and y absolute values of said position markers (21-24) in said xy coordinate system of said sewing system (1). a method comprising the steps of: Method according to claim 1, characterized in that the exact x and y coordinates of the four position markers (21-24) on the sewing material holder (9; 25) are known. A method according to claim 1 or 2, characterized in that additional sewing material holder-specific information about the coordinates of the position markers (21-24) is collected. Before the step of recording the actual image, as a preparatory step,
attaching the position markers (21-24) to the sewing material holder;
determining the x and y coordinates of each position marker (21-24) in the xy coordinate system of the sewing system (1);
4. A method according to any one of claims 1 to 3, characterized in that performing A sewing material holder (9; 25) for carrying out the method according to any one of claims 1 to 4, comprising:
Sewing material holder, characterized in that it has at least four position markers (21-24) which are displayed when recording said real image. 6. Sewing material holder according to claim 5, characterized in that it has exactly four position markers (21-24). The sewing material holder according to claim 5 or 6, characterized in that it comprises at least one information carrier (31) containing sewing material holder-specific information regarding the coordinates of the position markers (21-24). 8. Sewing material holder according to claim 7, characterized in that the information carrier (31) is designed as a QR code. A sewing system (1) for carrying out the method according to any one of claims 1 to 4, comprising:
at least one sewing machine (2) for sewing seam contours by executing a created sewing program; and
Sewing system (1), characterized in that it comprises at least one sewing material holder (9; 25) according to any one of claims 5-8. 10. Sewing system according to claim 9, characterized in that it comprises a set of sewing material holders (9; 25) according to any one of claims 5-8.

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