Verification method for ensuring that suture is located in suture area in air bag glue path

Abstract

The invention discloses a verification method for ensuring that a suture is located in a suture area in an air bag glue path, and belongs to the technical field of visual inspection. Comprising the steps of setting a position threshold of a suture in a glue path; the air bag gluing standard part is placed in a visual measurement unit station; the visual measurement unit enters a designated position to identify the glue path, and the sewing unit sews the glue path at the designated position; the visual measurement unit obtains a first image of a glue path sewing line at a specified position; setting a comparison air bag gluing standard part, covering a verification part with a verification glue path on a glue path at a specified position, and carrying out glue path identification; the sewing unit sews the verification glue path at the specified position to obtain a second image of the specified position; comparing and verifying the position coordinate difference of the stitches of the first image and the second image, and starting a sewing unit compensation mechanism when the coordinate difference value exceeds the position threshold value of the stitches in the glue path; and repeating visual verification. The problem that verification is tedious in the actual sewing process of a current air bag visual detection algorithm is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of visual inspection, and more particularly to a verification method for ensuring that a suture is located in a suture area within an airbag adhesive path. Background Art

[0002] As a core component of a vehicle's passive safety, airbags rapidly inflate and deploy in a collision, cushioning the impact between the occupants and the vehicle body and reducing the risk of casualties. Airbags require stitching during production. Typically, the stitching area is drawn on the airbag by applying glue before stitching. The airbag stitching connects the airbag cover to the airbag body, ensuring the airbag remains sealed when not triggered. When the airbag is triggered, the stitching quickly breaks along a pre-set path, which is the airbag glue path. The stitching must be strictly sewn along the middle of the airbag glue path.

[0003] The pass rate of current airbag visual sewing systems is affected by a variety of factors, including the front-to-back position of the airbag, inconsistent glue path widths during glue application, and the difficulty in extracting the stitching trajectory due to the numerous inflection points in complex areas such as the ear flaps. These factors ultimately lead to unsatisfactory stitching, with the stitches exceeding the set glue path position threshold. Because individual airbag glue paths are long, verifying the visual inspection algorithm typically requires continuous manual debugging to ensure the final airbag meets quality standards. This verification method is cumbersome and time-consuming.

[0004] Based on the above problems, we intercepted part of the glue path and verified the actual sewing of the visual algorithm. The actual output sewing trajectory was identified and converted in real time according to the actual glue path, realizing the function of visually guided sewing. By covering the glue path verification pieces with different paths, the sewing trajectory can fully verify the sewing process of different areas of the glue path at the same position. There is no need to let the sewing unit sew the entire glue path. By continuously compensating the glue path sewing trajectory, we finally optimize the visual glue path sewing trajectory extraction algorithm to ensure the product qualification rate. Summary of the Invention

[0005] In order to overcome the problem of cumbersome verification during actual sewing of the current airbag visual detection algorithm raised in the above-mentioned background technology, the present invention provides a verification method to ensure that the stitches are located in the stitching area within the airbag glue path. Through this method, the actual sewing of the visual algorithm is verified, and the actual output sewing trajectory is identified and converted in real time according to the actual glue path, thereby realizing the function of visually guided sewing.

[0006] In order to solve the above technical problems, the technical solutions of the present invention are as follows: A verification method for ensuring that a suture is located in a suture area within an airbag adhesive path comprises: Set the position threshold of the suture in the glue path; Place the airbag glue coating standard parts in the visual measurement unit station; The visual measurement unit enters the designated position to identify the glue path, and the sewing unit sews the glue path at the designated position; The visual measurement unit obtains a first image of the glue path suture at a designated position and obtains the coordinates of the suture position in the first image; Set up a comparison airbag glue coating standard part, and cover the verification part with the verification glue path on the glue path at the specified position to identify the glue path; The sewing unit sews the glue path for verifying the designated position, obtains a second image of the designated position, and obtains the coordinates of the stitching position in the second image; Compare and verify the difference in the stitch position coordinates between the first image and the second image. When the coordinate difference exceeds the threshold of the stitch position in the glue path, activate the sewing unit compensation mechanism. Set the comparison airbag glue coating standard again and repeat the visual verification.

[0007] The coordinates on the image are extracted through calibration methods, such as chessboard calibration.

[0008] The verification glue path on the verification piece is obtained by printing.

[0009] In some areas, such as the outer contour of the glue path, the edges are usually fixed with a jig to the airbag material. Therefore, the verification part can be installed along the inner edge of the jig to ensure that the glue path in the designated area is completely covered, preventing the vision measurement unit from entering the area and correctly identifying the verification glue path and sewing from the verification glue path.

[0010] Preferably, the verification piece divides the glue path at the designated position, and the designated dividing position is the first position and the second position according to the moving direction of the sewing unit; the two ends of the verification glue path of the verification piece are set as the third position and the fourth position; wherein, The first and third positions of the glue path are connected; the fourth and second positions of the glue path are connected, and it is verified that the remaining positions of the glue path deviate from the designated positions and are covered by the glue path.

[0011] This embodiment ensures that the verification glue path can be correctly identified, and avoids the suture directly exceeding the set threshold when the suture enters the verification glue path, resulting in suture verification failure.

[0012] Preferably, there are multiple verification pieces, and a single verification piece is provided with a curved verification rubber path; multiple verification pieces containing curved verification rubber paths with different degrees of curvature are sequentially covered with the designated position rubber paths, and comparison images are sequentially obtained.

[0013] Preferably, the curve of the glue path verified by a single verification member includes at least one inflection point.

[0014] Preferably, the position threshold includes a minimum distance from the suture to the inner line of the verification glue path and a minimum distance from the suture to the outer line of the verification glue path.

[0015] Preferably, the glue path adopts a width of 8.5 mm, the minimum distance from the suture to the inner edge of the glue path does not exceed 3 mm, and the minimum distance to the outer edge of the glue path does not exceed 2 mm. Within the range within the above thresholds, the suture trajectory is judged to be qualified.

[0016] Preferably, the inner line and outer line of the third position verification glue path do not exceed the inner line and outer line of the first position glue path; the inner line and outer line of the fourth position verification glue path do not exceed the inner line and outer line of the second position glue path.

[0017] Preferably, the verification glue path of the verification piece is obtained by color extraction.

[0018] Compared with the existing technology, the beneficial effect of the technical solution of the present invention is: by printing multiple verification pieces containing different glue paths, the verification glue path is intercepted in part of the glue path area for comparison with the standard glue path, thereby simulating the entire airbag glue path suture trajectory, without the need to sew the entire glue path completely. After comparison, the algorithm for extracting the suture trajectory of the visual glue path is continuously optimized, and ultimately the qualified rate of the airbag finished product suture is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 Schematic diagram of the specific steps of the present invention; Figure 2 Schematic diagram of the verification glue path of different bending degrees of the present invention; Figure 3 A schematic diagram of a verification glue path for multiple inflection points of the present invention; Figure 4 This is a schematic diagram of the verification pieces of different bending degrees of the present invention after being installed at the designated glue path position; Figure 5 For the present invention Figure 4 Extract the suture trajectory diagram from the suture; Figure 6 For the present invention Figure 4 Schematic diagram of the verification piece after verifying the glue path and stitching; Figure 7 This is a schematic diagram of the multi-folding point verification piece of the present invention after being installed at the designated glue path position; Figure 8 For the present invention Figure 7 Schematic diagram of suture trajectory for partial verification of glue path extraction. DETAILED DESCRIPTION

[0021] In order to better understand the purpose, structure and function of the present invention, the technical solution of the present invention is further described in detail below with reference to the accompanying drawings and specific preferred embodiments.

[0022] In the description of the present invention, it should be understood that the terms "left side", "right side", "upper part", "lower part", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second", etc. do not indicate the importance of the components and therefore cannot be understood as limiting the present invention. The specific dimensions used in the embodiments are only for illustrating the technical solutions and do not limit the scope of protection of the present invention. It is understandable to those skilled in the art that some well-known structures and their descriptions in the drawings may be omitted.

[0023] Unless otherwise expressly specified or limited, terms such as "installed," "installed," "connected," and "fixed" should be interpreted broadly. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0024] The present invention is based on a visual detection suture device, wherein the visual detection suture device includes but is not limited to a visual measurement unit, a light source, a sewing unit, a moving unit (for moving the visual measurement unit and the sewing unit), a work station (for placing the finished airbag), a fixture (for fixing the airbag), and a system (for receiving input signals from the visual measurement unit and controlling the movement of the moving unit and the sewing unit). The system also includes visual measurement and sewing algorithms.

[0025] See also Figure 1 The present invention provides a verification method for ensuring that the suture is located in the suture area within the airbag glue path, comprising: Step 11: Set the position threshold of the suture in the glue path, such as Figure 4A specific schematic diagram is shown after the verification part is installed in the designated glue path position. In the figure, the width of the standard glue path is set to 8.5mm, the minimum distance from the suture to the inner edge of the glue path is set to no more than 3mm, and the minimum distance to the outer edge of the glue path is set to no more than 2mm. Within the range of the above thresholds, the suture trajectory is judged to be qualified.

[0026] The purpose of setting the threshold is to verify the possibility of making the glue path narrower in the future. When sewing automobile airbags, the stitching trajectory needs to fall into the glue path. However, considering that the glue path is relatively wide in the existing process and the position of the stitching in different workpieces fluctuates greatly, a threshold is set for the range of the stitching trajectory in the glue path through visual guidance. By narrowing the sewing range of the stitching, further pave the way for making a narrow glue path.

[0027] Step 12: Place the airbag glue coating standard part in the visual measurement unit station and fix the airbag with a fixture.

[0028] Step 13: The system sets a program to drive the moving mechanism to drive the visual measurement unit to enter the designated position to identify the glue path, and the sewing unit sews the glue path at the designated position.

[0029] More specifically, the verification glue path of the verification part is obtained by color extraction, and the glue path recognition algorithm steps include acquiring an initial image; image preprocessing, including denoising, lighting correction, and color extraction, by converting the RGB image into an HSV image; color segmentation; morphological operation optimization, performing corrosion and expansion operations on the image after color segmentation to optimize the image; extracting the area, and finally obtaining the ROI area.

[0030] Step 14: The visual measurement unit obtains the first image of the glue line at the designated location and obtains the coordinates of the suture position in the first image. The system accepts the image returned by the visual measurement unit and the algorithm generates the following Figure 5 The system then drives the sewing unit to sew along the sewing trajectory within the glue path threshold according to the stitching trajectory coordinates shown.

[0031] Step 15: Set up the comparison airbag glue standard part, cover the verification part with the verification glue path on the designated glue path, and identify the glue path. Verify that the width of the glue path does not exceed 8.5mm. Figure 4-5 Show a verification glue path with a curve, such as Figure 6-8 A multi-inflection point verification rubber path is shown. All the above verification rubber paths use a 7mm verification rubber path to ensure that both ends of the verification rubber path are connected to the calibration rubber path.

[0032] Step 16: The sewing unit sews the glue path at the designated position, obtains the second image of the designated position, obtains the coordinates of the second image stitch position, and the final image is as follows: Figure 6 Suture diagram shown.

[0033] Step 17: Compare and verify the difference in the suture position coordinates between the first image and the second image. When the coordinate difference value exceeds the threshold value of the suture position in the glue path, start the sewing unit compensation mechanism. The sewing unit compensation mechanism uses a compensation algorithm to optimize the suture trajectory to ensure that the suture falls within the threshold range inside the glue path.

[0034] The purpose of the sewing unit compensation mechanism here is to control the suture within the threshold range set in the glue path, for example, first select the ROI area through the visual measurement unit; calibrate the coordinates in the area, for example, set the threshold in the area. If there are two parallel lines, when the coordinates of the tail end of a needle in the suture do not fall into the calibration area, the suture is controlled within the threshold through computer program optimization; if it is a curved glue path, the glue path can be divided into multiple approximately rectangular areas by segmentation, and a sewing line stroke can span one or more adjacent rectangular areas. The threshold range is determined by segmentation to verify whether the suture is within the threshold range.

[0035] For the two parallel lines of the suture threshold, the specific formula is: L1: ax+by+c1=0; L2: ax+by+c2=0; L3: ax+by+c3=0; Among them, L1 and L2 represent two parallel lines, L3 represents the suture line; (c2-c1) / √(a 2 +b 2 ) represents the line spacing; if all points in the stitch line L3 are located in the rectangular area formed by L1 and L2, it is judged to be qualified, otherwise it is judged to be unqualified.

[0036] Step 18: Set the comparison airbag glue coating standard parts again and repeat the visual verification. By replacing different verification parts, the complex glue path area of the entire glue path area is simulated and compared with the standard glue path stitching to verify and optimize the visual stitching algorithm.

[0037] On the basis of the above embodiment, further, the verification piece divides the glue path at the designated position, and the designated dividing position is the first position and the second position according to the moving direction of the sewing unit; the two ends of the verification glue path of the verification piece are set as the third position and the fourth position; wherein, The first and third positions of the glue path are connected; the fourth and second positions of the glue path are connected, and it is verified that the remaining positions of the glue path deviate from the designated positions and are covered by the glue path.

[0038] More specifically, the inner line and outer line of the third position verification glue path do not exceed the inner line and outer line of the first position glue path; the inner line and outer line of the fourth position verification glue path do not exceed the inner line and outer line of the second position glue path.

[0039] like Figure 2As shown in the figure, A, B, C, and D represent the first position, second position, third position, and fourth position respectively. When installing the verification part, first, it is necessary to ensure that the glue road at the specified position is completely covered to avoid deviations in visual identification; second, it is necessary to ensure that the C and D ends of the verification glue road are respectively connected to the A and B ends of the glue road at the specified position, and try to ensure that the center line of the verification glue road is consistent with the center line of the glue road at both ends of the specified position. When distinguishing the visual identification glue road, it is possible to smoothly transition from the specified glue road to the verification glue road.

[0040] On the basis of the above embodiment, further, the verification piece is provided with multiple, and a single verification piece is provided with a curved verification glue path; multiple verification pieces with curved verification glue paths of different curvature degrees are sequentially covered with the glue paths at the designated positions, and comparative images are sequentially obtained, such as Figure 2 The verification glue path shown shows a verification piece containing verification glue paths with different degrees of curvature. This embodiment is to simulate the suture trajectories of verification glue paths with different degrees of curvature in sequence to verify the suture trajectories of glue paths with different degrees of curvature in the complete glue path of the airbag.

[0041] Based on the above embodiment, further, the curve of the single verification member verification glue path includes at least one inflection point, such as Figure 3 The verification glue path shown shows that in some cases, the glue path contains multiple inflection points. The glue path is verified by simulating multiple inflection points to simulate the glue path suture trajectory of multiple inflection points in other positions in the complete glue path.

[0042] More specifically, the position threshold includes the minimum distance from the suture to the inner line of the verification glue path and the minimum distance from the suture to the outer line of the verification glue path, such as Figure 4-8 As shown in the figure, the verification glue path shown is 7mm wide, the minimum distance from the suture track to the inner line of the verification glue path is 3mm, and the minimum distance from the suture track to the outer line of the verification glue path is 2mm. The middle area is set as the threshold area, and the sutures within the threshold area are judged to be qualified.

[0043] The present invention performs verification by covering part of the glue path in the complete glue path with the verification piece. After the original glue path is covered, the visual algorithm can still sew through the verified glue path, and the actual output sewing trajectory is obtained, which is recognized and converted in real time according to the actual glue path, verifying the function of visually guided sewing. At the same time, the advantage of using the verification piece is that it can simulate the trajectory of complex glue paths in other areas of the complete glue path, such as glue paths with different degrees of curvature, or some glue paths with multiple inflection points. The complete glue path can be verified at the specified position through the verification piece, which reduces manual debugging time and greatly saves verification costs.

[0044] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A verification method for ensuring that the suture is located in the suture area within the airbag glue path, characterized in that: The steps include: Set the position threshold of the suture in the glue path; Place the airbag glue coating standard parts in the visual measurement unit station; The visual measurement unit enters the designated position to identify the glue path, and the sewing unit sews the glue path at the designated position; The visual measurement unit obtains a first image of the glue path suture at a designated position and obtains the coordinates of the suture position in the first image; Set up a comparison airbag glue coating standard part, and cover the verification part with the verification glue path on the glue path at the specified position to identify the glue path; The sewing unit sews the glue path for verifying the designated position, obtains a second image of the designated position, and obtains the coordinates of the stitching position in the second image; Compare and verify the difference in the stitch position coordinates between the first image and the second image. When the coordinate difference exceeds the threshold of the stitch position in the glue path, activate the sewing unit compensation mechanism. Set the comparison airbag glue coating standard again and repeat the visual verification.

2. The verification method for ensuring that the suture is located in the suture area within the airbag glue path according to claim 1, characterized in that: The verification piece divides the glue path at the designated position, and the designated dividing position is the first position and the second position according to the moving direction of the sewing unit; the two ends of the verification glue path of the verification piece are set as the third position and the fourth position; wherein, The first and third positions of the glue path are connected; the fourth and second positions of the glue path are connected, and it is verified that the remaining positions of the glue path deviate from the designated positions and are covered by the glue path.

3. The verification method for ensuring that the suture is located in the suture area within the airbag glue path according to claim 1, characterized in that: There are multiple verification pieces, and each verification piece is provided with a curved verification glue path; multiple verification pieces containing curved verification glue paths with different curvature degrees are sequentially covered with the glue paths at designated positions, and comparison images are sequentially obtained.

4. The verification method for ensuring that the suture is located in the suture area within the airbag glue path according to claim 3, characterized in that: The curve of the glue path verified by a single verification piece includes at least one inflection point.

5. The verification method for ensuring that the suture is located in the suture area within the airbag glue path according to claim 1, characterized in that: The position threshold includes a minimum distance from the suture to the inner line of the verification glue path and a minimum distance from the suture to the outer line of the verification glue path.

6. The verification method for ensuring that the suture is located in the suture area within the airbag glue path according to claim 2, characterized in that: The inner line and outer line of the third position verification glue road do not exceed the inner line and outer line of the first position glue road; the inner line and outer line of the fourth position verification glue road do not exceed the inner line and outer line of the second position glue road.

7. The verification method for ensuring that the suture is located in the suture area within the airbag glue path according to claim 1, characterized in that: The verification glue path of the verification piece is obtained by color extraction.

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