JP2016142611A - Inspection method and device of vehicle window glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection method and inspection device of a vehicle window glass that can easily evaluate transmission distortion of a window glass having a three-dimensional curve surface.SOLUTION: An inspection method of a vehicle window glass includes: a first image creation step S2 of creating a first lattice image where a lattice pattern is photographed; an image conversion step S3 of converting the fist lattice image into a second lattice image on a drawing format; a second image creation step S4 of creating a first gray scale image according to the second lattice image; a third image creation step S5 of creating a second gray scale image where an area outside a corresponding row evaluation range or a column evaluation range is removed from the first gray scale image; a fourth image creation step S6 of creating an evaluation image where a density of a pixel of the second gray scale image lower than a determination criterion is changed to a minimum density; and an evaluation step S7 of evaluating transmission distortion.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a vehicle wind glass inspection method and apparatus, and more particularly to a vehicle wind glass inspection method and apparatus for inspecting transmission distortion of wind glass using an external lattice pattern.

  In recent years, three-dimensional curved surfaces of window glass, particularly front window glass, have been advanced due to demands of vehicle design and the like. Since the driver views an external scenery or object through the front window glass while traveling, the scenery or object viewed through the curved portion of the front window glass is distorted according to the degree of bending. If the transmission strain associated with this three-dimensional curved surface is greater than or equal to an allowable value, the driver may feel annoyed. Also, the rear window glass is similarly troublesome when the transmission strain is large.

Although the inspection method of Patent Document 1 is not intended for curved glass, grid lines in the horizontal and vertical (row and column) directions are extracted from a grid image obtained by projecting a grid pattern on a plate glass, and The horizontal and vertical grid lines are labeled, the connection relation is determined based on the grid intersections of the labeled horizontal and vertical grid lines, and the plane distortion of the object is measured.
Thereby, the connection relation of the adjacent grid intersections can be easily grasped, and the plane strain can be measured.

Japanese Patent Laid-Open No. 1-319872

In the inspection method of Patent Document 1, the plane distortion can be measured by image processing using a lattice pattern, but the transmission distortion of the front window glass that can be perceived by the driver cannot be evaluated.
Therefore, the present inventor newly sets the following equation for calculating the strain consisting of the degree of strain and the strain area, and uses the lattice image obtained by imaging the external lattice pattern from the driver's eye point position of the front window glass. The transmission strain was evaluated.
Strain degree = (Absolute value of elongation and shrinkage (mm)) / (Standard lattice size (mm)) × location coefficient Strain area = NG lattice number / total lattice number × location coefficient

Here, the absolute values of expansion and contraction are determined by selecting the rows and columns in the lattice pattern to be measured, setting a reference line connecting the lattices that do not have any distortion, and then moving the reference line in the most positive direction. The number of NG lattices is the number of lattices displaced from the reference line, and the total number of lattices is the number of lattices adjacent to the reference line.
The location coefficient is set based on the intersection angle between the driver's line of sight and the front window glass. Specifically, the portion corresponding to the front of the driver was set to a large value, the portion corresponding to the front of the passenger on the passenger seat was set to an intermediate value, and the left and right end portions and the upper end portion of the front window glass were set to small values.

Although the above-described distortion calculation formula can be used to create an index in which the transmission distortion is quantified, the distortion portion of the lattice image is output as an unclear blurred image due to the mechanism of the imaging means.
Therefore, since the absolute values of expansion and contraction need to be determined by visual recognition by the worker, variations due to individual differences among workers cannot be avoided. Further, when the entire front window glass is inspected, there is a problem that it takes a long time for the strain calculation and cannot cope with the inspection of the mass production vehicle.

  An object of the present invention is to provide a vehicle wind glass inspection method, an inspection apparatus, and the like that can easily evaluate the transmission strain of a window glass having a three-dimensional curved surface.

  The vehicle window glass inspection method according to claim 1 is an inspection method for vehicle window glass in which transmission distortion of the window glass is inspected using an external lattice pattern, and the lattice pattern is imaged through the window glass. A first image creating step for creating a first grid image; an image converting step for converting the first grid image into a second grid image on a drawing format set in a pixel matrix corresponding to the grid pattern; A second image creation step for creating a first grayscale image based on the second grid image; and a second image obtained by removing portions of the pixel matrix that are out of the corresponding row or column region from the first grayscale image. A third image creating step for creating a gray scale image, and a pixel having a density equal to or higher than a determination threshold of the second gray scale image is minimized; Is characterized by having a fourth image generating step of generating an image for evaluation was changed every and an evaluation step of evaluating the transmission distortion of the window glass based on the evaluation image.

Since this vehicle window glass inspection method includes a second image creation step of creating a first grayscale image based on the second grid image, the first grid image is converted into grayscale information via the second grid image. can do.
Since there is a third image creation step for creating a second grayscale image in which the portions outside the corresponding row or column regions of the pixel matrix are removed from the first grayscale image, the amount of information is reduced. The calculation time can be shortened.
Since the image forming apparatus includes a fourth image creating step for creating an evaluation image in which pixels having a density equal to or higher than the determination threshold of the second gray scale image are changed to the minimum density, the distortion of the first grid image is displayed according to the gray level of the grid lines. It is possible to increase the operator's perception of transmission distortion. Here, the ease of recognition means that anyone can recognize quantitatively without any variation regardless of the operator. That is, the degree of transmission distortion of the window glass is perceptually expressed by an image expressed by replacing the amount of distortion of the lattice line due to transmission distortion with the density of a straight line having a predetermined width instead of the distortion.

The invention of claim 2 is characterized in that, in the invention of claim 1, in the first image creating step, the grid pattern is imaged from the eye point position of the driver.
According to this configuration, the transmission distortion perceived by the driver can be reliably inspected.

According to a third aspect of the present invention, in the first or second aspect of the invention, in the fourth image creation step, an intermediate evaluation image obtained by changing pixels having a density less than a determination threshold value of the second grayscale image to a minimum density. It is characterized in that an evaluation image is created by inverting the density.
According to this configuration, it is possible to further increase the operator's ability to recognize transmission distortion.

The vehicle window glass inspection apparatus according to claim 4 is an inspection apparatus for vehicle window glass that inspects transmission distortion of the window glass using an external lattice pattern, and images the lattice pattern through the window glass. First image creating means for creating a first grid image; image converting means for converting the first grid image into a second grid image on a drawing format set in a pixel matrix corresponding to the grid pattern; Second image creation means for creating a first grayscale image based on the second grid image; and a second image in which a portion out of the corresponding row or column region of the pixel matrix is removed from the first grayscale image. Third image creating means for creating a gray scale image, and an evaluation in which pixels having a density equal to or higher than the determination threshold of the second gray scale image are changed to the minimum density. It is characterized in that a fourth image generating means for generating a use images.
According to this configuration, since the distortion of the first grid image can be displayed by the shaded state of the grid lines, the operator can easily recognize the transmission distortion.

  According to the inspection method and apparatus for vehicle window glass of the present invention, the transmission strain of a window glass having a three-dimensional curved surface can be easily evaluated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a vehicle front window glass inspection station according to a first embodiment. It is a top view of FIG. It is a block diagram of an inspection device. It is a drawing format. It is an example of a 2nd grid | lattice image. FIG. 6 is an enlarged view of a region A in FIG. 5. FIG. 7 is a first grayscale image of FIG. 6. It is the 2nd gray scale image of FIG. FIG. 9 is an intermediate evaluation image of FIG. 8. FIG. It is a step chart which shows the test | inspection procedure of the vehicle windshield. It is an example of the image for evaluation. It is an example of a reference image.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The following description exemplifies the application of the present invention to the inspection of the front window glass W of the vehicle V, and does not limit the present invention, its application, or its use.

Hereinafter, Example 1 of the present invention will be described with reference to FIGS.
In this embodiment, as shown in FIGS. 1 to 3, an inspection method and an inspection apparatus for inspecting transmission distortion of a front window glass W having a three-dimensional curved surface will be described.
Here, the transmission distortion refers to the shape of the object when the driver sees an external object through the front window glass W while not sitting through the front window glass W while seated on the seat of the vehicle V. Is the distortion.

First, preconditions for transmission distortion inspection will be described.
After inspecting the left and right half of the front windshield W, the other half is inspected.
In the present embodiment, an inspection of the left half of the front window glass W mounted on the right-hand drive vehicle V will be described as an example.
As shown in FIGS. 1 and 2, a CCD as an imaging device 2 is arranged at a position corresponding to the driver's eye point, and a grid panel 5 having a grid pattern 6 in an orthogonal grid pattern is used as the driver's line of sight. It arrange | positions so that it may orthogonally cross. The driver's line of sight is an extension line L that connects the driver's eye point equivalent position and the center position of the left half of the windshield W.
In the case of the inspection of the right half of the front windshield W, the eye point equivalent position is set assuming the left-hand drive vehicle V.

The lattice panel 5 is fixed on a base installed on the floor, the lower end of the lattice panel 5 is lower than the lower end of the front window glass W, and the upper end is higher than the upper end of the front window glass W. It is set to be.
The lattice pattern 6 is formed such that a plurality of row lattice lines extending in the left-right direction and a plurality of column lattice lines extending in the up-down direction intersect each other in an orthogonal manner. Each grid size is formed in a square shape of 10 mm × 10 mm, and the thickness of the row and column grid lines is set to 1 mm.

The grid size is within the range of 5 mm × 5 mm to 20 mm × 20 mm when the distance from the imaging device 2 disposed at the eye point equivalent position to the grid panel 5 (hereinafter referred to as the grid distance) is set to 2.5 mm. If there is, the grid pattern 6 can be easily imaged by the general-purpose imaging device 2. Preferably, the grid size of 10 mm × 10 mm is most excellent in terms of image quality accuracy when grid distortion is included.
If the lattice distance is within a range of 2.5 m to 4.0 m when the lattice size is set to 10 mm × 10 mm, the general-purpose imaging device 2 can easily capture the lattice distortion.

Next, the inspection apparatus 1 for the front window glass W will be described.
As shown in FIG. 3, the inspection device 1 includes an imaging device 2 (first image creation means) that can image the lattice pattern 6, an output device 3, a control device 4 that can transmit / receive data to / from these devices, and the like. ing.
The imaging device 2 is made of, for example, a CCD, a digital camera, or the like, and is configured to be able to create a first grid image (not shown) having RGB by capturing the grid pattern 6 through the left half of the front window glass W. .
The output device 3 includes a display device such as a display and a CRT, a printing device such as a printer, and the like, and is configured to output an evaluation image 26 (see FIG. 11).

  The control device 4 is configured to input information on the first grid image captured by the imaging device 2 and to display the distortion of the front window glass W included in the first grid image according to the shade state of the row and column grid lines. Has been. The control device 4 is an integrated numerical arithmetic device having a CPU that executes various programs, a ROM that stores various control programs, a RAM that stores determination threshold values and various parameters, an input interface, an output interface, and the like. .

The control device 4 has a drawing format 31 composed of a set of a plurality of pixels 33.
As shown in FIG. 4, the drawing format 31 includes a pixel matrix 32 in which a plurality of pixels 33 are arranged in the row and column directions, respectively. In the pixel matrix 32, a plurality of row evaluation ranges 34 (row regions) and column evaluation ranges 35 (column regions) respectively corresponding to the plurality of row grid lines and column grid lines of the grid pattern 6 are set.

The control device 4 includes an image conversion unit 11 (image conversion unit), a second image generation unit 12 (second image generation unit), a third image generation unit 13 (third image generation unit), and a fourth image generation unit. A unit 14 (fourth image creating means) is provided.
As shown in FIGS. 5 and 6, the image conversion unit 11 is configured to be able to convert the information of the first lattice image onto the pixel matrix 32 of the drawing format 31 as the second lattice image 22.
In the pixel matrix 32, when the first grid image is converted into the second grid image 22, the row corresponding to the second grid image 22 and the thickness of the column grid line correspond to two rows (two columns) of the pixels 33. Is set in advance. Note that a parallel relationship is set corresponding to the row and column directions of the lattice pattern 6, the row and column directions of the first lattice image, and the row and column directions of the second lattice image 22.

The second image creation unit 12 creates a first grayscale image 23 by performing grayscale conversion on the second grid image 22 converted on the pixel matrix 32.
As shown in FIG. 7, the second image creation unit 12 deletes the hue information and the saturation information while maintaining the luminance of the second grid image 22 having RGB, thereby obtaining the first grayscale image 23. Is forming. The first grayscale image 23 is defined only by light and shade information from density 0 (dark) to density 255 (bright). For gray scale conversion, a method suitable for appropriate conditions such as an intermediate value method using an average value of RGB and a weighted average method of weighting RGB can be adopted.

The third image creation unit 13 creates a second grayscale image 24 in which a portion outside the row evaluation range 34 or the column evaluation range 35 in the first grayscale image 23 is removed.
Since the same processing is performed for the column grid lines, the row grid lines will be mainly described below.
As shown in FIG. 8, the row evaluation range 34 is set to an area where row grid lines exist if there is no distortion, and a portion that deviates from the row evaluation range 34 is a portion that includes distortion. Therefore, in the second grayscale image 24, the maximum density portion of the row evaluation range 34 indicates a portion that is greatly distorted from the position where the row grid line should be present, and the minimum density portion of the row evaluation range 34 indicates the minimum density portion. The portion where the row grid lines are present without distortion is shown, and the intermediate density portion is the portion where the row grid line occupancy with respect to the pixel 33 where the row grid lines should originally exist is reduced due to the row grid lines being distorted Is shown. This makes it possible to reduce the amount of information while clearly distinguishing the part of the row grid line that contains distortion from the part that does not contain distortion, and shortens the computation time in the subsequent process. Yes.

The fourth image creating unit 14 creates the evaluation image 26 in which the density is inverted after changing the density portion of the second grayscale image 24 that is less than the determination threshold to the minimum density 0.
In the row evaluation range 34, a portion having a density less than the determination threshold, for example, density 128, is a portion where the row grid lines are present without being distorted or a portion where the row grid lines are slightly distorted. In the row evaluation range 34, a portion having a density equal to or higher than the determination threshold is a portion that is greatly distorted from the position where the row grid line should exist.
As shown in FIG. 9, the fourth image creation unit 14 includes a portion where the row grid lines are present in the row evaluation range 34 without being distorted, and a portion where the row grid lines are slightly distorted from the position where the row grid lines should be present. An intermediate evaluation image 25 in which is changed to a single minimum density is created.

As shown in FIG. 11, the fourth image creation unit 14 creates the evaluation image 26 by inverting the density of the intermediate evaluation image 25. Thereby, it is possible to clarify the density of the row grid lines to be inspected with respect to the background color. Further, since the evaluation image 26 maintains the intermediate density of the row grid lines including slight distortion, when inspecting the transmission distortion, the magnitude including the transmission distortion is easily recognized by the blurred state of the grid lines. And the ease of recognizing distortion can be increased.
The control device 4 outputs information on the evaluation image 26 to the output device 3, and the output device 3 displays or prints the evaluation image 26. The operator can inspect the transmission distortion of the front window glass W based on the evaluation image 26 displayed or printed.

Next, an inspection procedure for inspecting the transmission strain of the front window glass W will be described with reference to FIG. Si (i = 1, 2,...) Indicates each step.
First, in S1, a preparation step is performed.
In the preparation step, the grid pattern 6 of the above standard size is arranged on the grid panel 5 at the inspection station, the imaging device 2 is arranged at a position corresponding to the eye point of the driver of the vehicle V, and the vehicle V is placed on the grid panel 5. Positioning at a predetermined facing angle.

Next, the grid pattern 6 is imaged by the imaging device 2 to create a first grid image (S2).
At this time, in the case of the right-hand drive vehicle V, imaging is performed so that the left half of the front window glass W is included in the entire area.
Next, as shown in FIG. 5, the first grid image is converted into the second grid image 22 on the drawing format 31 (S3).

In the second image creation step, a first grayscale image 23 is created based on the second grid image 22 (S4). As shown in FIG. 7, each pixel 33 on the drawing format 31 is displayed with a density of 0 to 255.
Next, the second gray scale image 24 is created (S5).
In S5, a second grayscale image 24 is created by removing portions of the pixel matrix 32 that are out of the corresponding row and column evaluation ranges 34 and 35 from the first grayscale image 23 (see FIG. 8).

Next, a fourth image creation step is performed (S6).
In the fourth image creation step, the intermediate evaluation image 25 (see FIG. 9) is created by changing the pixel 33 having a density lower than the determination threshold of the second grayscale image 24 to the minimum density, and then the intermediate evaluation image 25 The evaluation image 26 is created by inverting the density.
Finally, the transmission distortion of the front window glass W is inspected using the evaluation image 26 (S7).

As shown in FIG. 11, in the present embodiment, there are a plurality of portions where the lattice lines are interrupted from the upper left region to the lower right region. A portion where the lattice line is interrupted is a portion where a large transmission strain is generated, and a gray lattice line portion is a portion where a relatively small transmission strain is generated.
The evaluation image 26 and the reference image 27 (see FIG. 12) are compared, and the ratio of the portion where the transmission distortion occurs to the entire front window glass W, the ratio where the large transmission distortion (discontinuous portion) occurs, and the large transmission distortion. The transmission distortion of the front window glass W is inspected by comprehensively evaluating the generated parts and the like.
Note that after the inspection of the left half of the front window glass W is completed, the right half is inspected.

Next, the operation and effect of the inspection method for the vehicle front window glass W will be described.
According to the method for inspecting the front windshield W, since the second image creation step S <b> 4 for creating the first grayscale image 23 based on the second grid image 22 is provided, the first grid image is transmitted via the second grid image 22. Can be converted into shading information.
To provide a third image creation step S5 for creating a second grayscale image 24 from which the portions outside the corresponding row evaluation range 34 or column evaluation range 35 of the pixel matrix 32 are removed from the first grayscale image 23. The amount of information can be reduced, and the calculation time can be shortened. Since there is a fourth image creation step S6 for creating an evaluation image 26 in which the pixels 33 having a density equal to or higher than the determination threshold value of the second grayscale image 24 are changed to the minimum density, the distortion of the first grid image is represented by the shaded state of the grid lines. The operator can easily recognize the transmission distortion. Here, the ease of recognition means that anyone can recognize quantitatively without any variation regardless of the operator. In other words, the amount of distortion of the front window glass W is perceptually expressed by an image expressed by replacing the amount of distortion of the lattice line due to the transmission distortion with a straight blurring (density) state having a predetermined width. doing.

In the first image creation step S2, since the lattice pattern 6 is imaged from the eye point position of the driver, the transmission distortion perceived by the driver can be reliably inspected.
In the fourth image creation step S6, the evaluation image 26 is created by reversing the density of the intermediate evaluation image 25 in which the pixels having a density lower than the determination threshold of the second grayscale image 24 are changed to the minimum density. The operator's ease of recognition of distortion can be further increased.
According to the inspection apparatus 1 for the front windshield W, basically, as in the inspection method for the vehicle front windshield W, the distortion of the first grid image can be displayed by the gray level of the grid lines. It is possible to increase the operator's recognition.

Next, a modified example in which the embodiment is partially changed will be described.
1) In the above-described embodiment, an example of the front window glass has been described. However, any window glass may be used as long as it is a window glass mounted on a vehicle. You may apply to an inspection apparatus.

2] In the above embodiment, an example in which a CCD is used as the imaging device has been described. However, a lattice pattern may be captured by a digital camera. Further, when a lattice pattern is imaged by a digital camera, it is also possible to process with the digital camera until the second image creation step.

3] In the above embodiment, the example of the inspection method and the inspection apparatus for inspecting the transmission distortion that can be seen through the front window glass already mounted on the vehicle has been described. It may be applied to the inspection. In this case, the same arrangement state (height position and inclination angle) as when the front window glass is mounted on the vehicle is used.

4) In the above-described embodiment, the example in which the determination threshold is set to the density 128 has been described. However, the determination threshold is optimally appropriate depending on the inspection environment (for example, illuminance, weather, season, etc.) and the use of the front window glass (for example, curvature, area, etc.). A determination threshold can be set.
Further, the example in which the image for evaluation is created by inverting the density of the intermediate evaluation image has been described, but the minimum density and the maximum density in the image for intermediate evaluation are reversed and displayed, and the intermediate density portion is reversed. May be omitted. Thereby, processing can be simplified.

5] In addition, those skilled in the art can implement the present invention with various modifications added without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

DESCRIPTION OF SYMBOLS 1 Inspection apparatus 2 Imaging apparatus 4 Control apparatus 6 Grid pattern 11 Image conversion part 12 2nd image creation part 13 3rd image creation part 14 4th image creation part 22 2nd grid image 23 1st gray scale image 24 2nd gray scale Image 25 Intermediate evaluation image 26 Evaluation image 31 Drawing format 32 Pixel matrix 33 Pixel 34 Row evaluation range 35 Column evaluation range W Front window glass V Vehicle

Claims (4)

In the inspection method for vehicle wind glass, which inspects the transmission distortion of wind glass using an external lattice pattern,
A first image creating step of creating a first lattice image that images the lattice pattern through the window glass;
An image conversion step of converting the first lattice image into a second lattice image on a drawing format set in a pixel matrix corresponding to the lattice pattern;
A second image creation step of creating a first grayscale image based on the second grid image;
A third image creation step of creating a second grayscale image by removing a portion out of the corresponding row or column region of the pixel matrix from the first grayscale image;
A fourth image creation step of creating an evaluation image in which pixels having a density lower than the determination threshold of the second grayscale image are changed to a minimum density;
An evaluation step for evaluating the transmission distortion of the window glass based on the evaluation image;
A method for inspecting a window glass for a vehicle, comprising:   The vehicle window glass inspection method according to claim 1, wherein in the first image creation step, the grid pattern is imaged from a driver's eye point position.   In the fourth image creation step, an evaluation image is created by inverting the density of an intermediate evaluation image in which pixels having a density lower than the determination threshold of the second grayscale image are changed to a minimum density. The inspection method of the window glass for vehicles of Claim 1 or 2. In vehicle wind glass inspection equipment that inspects transmission distortion of wind glass using an external lattice pattern,
First image creating means for creating a first lattice image that images the lattice pattern through the window glass;
Image conversion means for converting the first grid image into a second grid image on a drawing format set in a pixel matrix corresponding to the grid pattern;
Second image creation means for creating a first grayscale image based on the second grid image;
Third image creating means for creating a second gray scale image obtained by removing a portion out of the corresponding row or column region of the pixel matrix from the first gray scale image;
A vehicle window glass inspection apparatus comprising: fourth image creation means for creating an evaluation image in which pixels having a density equal to or higher than a determination threshold of the second gray scale image are changed to a minimum density.