Method for forming master data for inspecting protruding and recessed figure

TECHNICAL FIELD

The present invention relates to a method for creating master data used to study a concave-convex shape on a tire surface or more.

METHOD

The method of automatically testing a concave-convex shape on a tire's surface is to test whether the concave-convex part of the tire is properly marked as a predetermined string of characters in a fixed place (e.g. according to patent documents 1) by aiming a light source at the sidewall of the tire on which the concave-convex part is located; choosing a bright line on the side wall resulting from lighting by the image recording device; reading and processing data from this image corresponding to a character or string; processing the image data into a string according to the concave-convex part tested; comparison of the processed string with the string previously saved in the master data. Patent documents 1: Japanese Patent Publication No. 10-115508

According to the current method, when testing a section of a mark in the form of image information obtained by measuring a tire, this image is treated as basic data. Therefore, it is influenced by a number of factors, such as resolution, accuracy, field of view or blind point, which are related to the measuring device. In addition, it is impossible to eliminate changes because the master data contain a position error with each measurement.

In addition, it is impossible to create a reference master data, because variations may occur within the tire selected to create the master data, and this tire need not necessarily be the standard reference point, even if it is in the range of standard values.

Moreover, if the tires come in different sizes, it is necessary to carry out measurements for all these sizes, which requires a lot of time to create a basic database.

We would like to draw your attention to the disclosures of WO 03/023699 and JP 63 201876.

DISCLOSURE OF THE INVENTION

The object of the present invention is to eliminate errors and provide a method for creating master data for examining concave-convex shapes, allowing accurate master data to be created without deviations and easy creation of master databases.

In order to achieve the above-mentioned objective, a method based on the first aspect of the invention has been developed according to claim 1.

Since the master data used for comparison with the concave-convex shape on the tire surface is based on the tire CAD drawings, there will be no deviations and

- thanks to this - it will be possible to create accurate basic data. In addition, since it will be possible to create accurate master data without deviations, it will also be possible to improve the accuracy of concave-convex shape comparisons on the tire surface.

In addition, according to the method used so far, if the tested tires had different sizes, it was necessary to take basic data measurements for all these sizes. The new method of the invention presented here allows to minimize the energy for creating a master database, because master data can be created regardless of the size of the tires and one set of master data is sufficient for one shape.

BRIEF DESCRIPTION OF THE DRAWINGS [Fig. 1] Fig. 1 schematically shows the tire sidewall surface with many shapes.

[Fig. 2] Fig. 2 schematically shows the device for testing the concave-convex shape of the tire.

[Fig. 3] Figs. 3a to 3c schematically show the differences between a shape and a shape model.

[Fig. [Fig. 4] Fig. 4 is a block diagram showing the operation process of the shape modeling device.

[Fig. [Fig. 5] Fig. 5 schematically shows the shape arrangement in a CAD drawing.

[Fig. [Fig. 6] Fig. 6 schematically illustrates example detailed shape information.

[Fig. [Fig. 7] Fig. 7 schematically illustrates an example gray scale change process.

[Fig. [Fig. 8] Figs. 8a to 8c schematically show a shape change process.

[Fig. [Fig. 9] Fig. 9 schematically shows the change in size and polar coordinates to rectangular coordinates.

[Fig. [Fig. 10] Fig. 10 schematically shows the image size and arrangement of the reference position.

[Fig. 11] Fig. 11 shows an example table of additional data.

THE BEST WAY TO PERFORM THIS INVENTION

Before the new master data creation method of the invention is explained, the method of operation of the concave-convex tire-testing device using the master data created according to the method of the invention will be explained.

Fig. 1 schematically shows the sidewall surface of a T tire with many concave-convex shapes and explains the three-dimensional shape 20, designated "a" in Fig. 1. Please note that the shapes marked in Fig. 1 as "b" or "c "May be tested in the same way as shape" a ".

Fig. 2 schematically shows an apparatus for testing a three-dimensional concave convex tire pattern. The device for testing the concave-convex tire pattern 10 consists of:

a component for obtaining data on concave-convex parts 1 to obtain data on the arrangement of concave and convex elements on a specified section of the tire surface, i.e. shape 20; a component for saving shape 2 data to create a (basic) database of the shape model making up the individual shape model, also including shape 20, and additional data tables containing shape layout information; a data processing component 3 used to determine a portion of the tire surface corresponding to this shape model based on data obtained from the component for obtaining concave-convex parts 1 and data on the input shape model derived from the component for recording shape 2 data, as well as for determining, whether the three-dimensional form of this shape is correct based on the agreement between the data on the distribution of concave and convex parts of a given fragment of the tire surface and data on the shape model; component displaying results 4; the whole device control component 5.

The component for obtaining data about concave-convex parts 1 consists of: a semiconductor laser 6 emitting a uniform beam of light (light knife) 12 propagating in the form of a fan; a two-dimensional camera 7 for capturing the luminous line 13 which the light knife 12 forms on the lateral surface of the tire T; devices for rotating the tire 8 at a predetermined speed or for gradually moving the tire in a circumferential direction according to a fixed pitch; device for creating data of shape 9, which collects image data from the camera 7 obtained at set intervals during the rotation of the tire, i.e. data on a clear line 13 only from data about a specific image, and creating data on a three-dimensional distribution of data about concave and convex parts on the entire surface of the ring-shaped tire.

The method of creating a working profile (data of three-dimensional shape) by collecting images of bright lines that arise on an object when it is illuminated with a light knife when it is moved is generally called the light cross-section method. The component for obtaining concave-convex parts 1 can obtain accurate data with a three-dimensional shape directly thanks to the images collected using the light cross-section method.

In addition, the component for saving shape 2 data stores the (basic) data of the shape model. Figures 3a to 3c schematically show the differences between a shape and a shape model; Fig. 3a schematically illustrates the shape 20, and Fig. 3b schematically illustrates the shape model being the shape 20. In this example, the shape 20 is the letter "A". Generally, the test is the shape constituting the element obtained by joining the profile line 20b and the inner part 20a formed by the profile lines 20b, while the shape model is a tool that is verified using concave-convex part distribution data. The shape model 22 shown in the example in Fig. 3b is defined by a rectangular area comprising the shape 20 and its perimeter.

The data on the distribution of concave-convex parts obtained from the image from camera 7 show the actual profile of the tire surface. Therefore, the actual concave convex shape on the surface of the tire, obtained from the data on the distribution of concave-convex parts, is such that the outer part of the tire in the radial direction is extended compared with the inner part of the tire in the radial direction, if compared with shape 20 on shape model 22. In the event that we want to obtain a part of the tire surface corresponding to the model of figure 22 or when we decide whether to consider the shape to be correct, it is necessary to check the dimensions of the shape model in such a way that it is deformed to obtain a shape compatible with the size of the tire and the part of the surface that we want adjust. For this purpose, we use the shape model after its deformation by applying polar coordinate conversion and size deformation, where the beginning is the center of the tire shown in the shape model 22. The shape shown in the schematic way in Fig. 3c is the shape model after deformation 22A, constituting the shape model 22, which uses polar coordinate conversion and size deformation.

As mentioned above, in order to create a shape model for determining whether tires of different sizes are acceptable, the component for saving shape 2 data saves the (basic) data of shape model 22, which is a shape model before applying polar coordinate conversion and size deformation, referred to above and which is depicted on a rectangular coordinate system in which the intersection points are marked at equal intervals.

In addition, the component for recording shape data 2 also stores information in the form of a data table regarding the shape model layout 22 that is different from the shape model 22 data of the tire under test. The layout information creates data about the central position of the shape model over the area of ​​the ring-shaped tire surface shown in Fig. 1. For example, the layout information for the shape model 22 is recorded as data about the middle position of the shape model 22, expressed as the distance R from the center of the tire and the angle θ in the circumferential direction relative to a fixed point on the tire surface.

The data processing component 3 operates as follows: acquires data about the distribution of concave-convex parts located in the area of ​​the tire surface containing shape 20 from the component for obtaining data about the concave-convex parts 1 on the basis of a command from the control component of the entire device 5; obtains pre-processed shape model data and shape layout information from a component for saving shape 2 data; determines the test area on the tire surface based on pre-processed information about the shape system 20; changes the position of the fragment of the tire surface within the test area corresponding to the shape model; determines the tire surface fragment for which the convergence between the data on the distribution of concave-convex parts of the tire surface fragment and the shape model data calculated in specific places is the largest; measures the convergence between the data on the distribution of concave-convex parts of the tire surface fragment and the data of the shape model 20; based on the aforementioned convergence determines whether the three-dimensional shape 20 is suitable.

According to the method of creating basic data for testing concave convex shapes described herein, the subject of the invention, on the basis of the shape data presented in the form of the CAD drawing of the tire forming matrix, the (basic) data of the above-mentioned shape model is created. Due to the fact that the shape data presented in the form of CAD drawings are fixed, according to the inventive method of creating master data, it is possible to create accurate master data that will not change.

The method for creating master data for examining concave-convex shapes will be explained later in the document.

In Fig. 2, the shape modeling device used to create master data for examining concave-convex shapes in accordance with the method described herein is designated by 11; this device for creating shape models operates on the basis of software. Fig. 4 is a block diagram of the process carried out by the device for creating shape models 11.

The basic data creation stage involves the following steps: processing CAD data to cut an image including a shape from a tire, and creating detailed shape information by adding position and height information; changing the gray scale to change the cut image according to the gray scale data corresponding to the height by using the shape height information in the detailed shape data; deforming the shape by using shape position information in the shape details.

First, the CAD data processing step will be explained. The shape modeling device 11 supports all CAD data from tire forming matrix files containing the CAD design data of the shape (e.g. DXF file) and displays the tire shape according to the CAD design on the display (stage 1). Then, based on the tire shape in accordance with the CAD design, the tire center point is calculated (stage 2). In this case, the center of the tire can be manually determined by the operator.

The shape is then selected based on the tire shape according to the CAD design (stage 3). In this case, the shape can be manually selected by the operator. If the shape was chosen based on the tire shape in accordance with the CAD design, the tangent lines running in the radial and circumferential direction of the tire will form a quadrilateral; then the image containing the shape is cut and saved in the data (step 4).

Then the shape system is determined and saved using the distance R of the quadrangle in the radial direction from the center of the tire (system diameter) and the offset angle (system angle) θ in the radial direction from the designated point on the tire (stage 5). Fig. 5 schematically shows the shape distribution in a CAD drawing of a tire.

The next stage is determining and saving the height (depth) of individual areas, so that the area defined by lines on the cut shape is considered to be a fixed height area based on the shape height information derived from the shape in the CAD drawing (stage 6) of the tire. The height can be set and saved by opening the numerical value input window and entering the height of individual shape areas from the outside. Then, in the numeric value input window, a shape identifier is entered to specify that shape.

Detailed shape information is created based on the above information (step 7). Fig. 6 shows exemplary detailed shape information. Detailed information about the cut shape includes at least the image data, shape number, shape layout, shape height, and shape designation.

Next, the gray scale change stage will be explained. The shape model 11 device changes the cut image, transforming it using CAD tools to a grayscale image corresponding to the height value in the detailed shape information (step 8). Grayscale is defined based on the "height range" value previously set as the image parameter and includes 256 levels obtained by dividing the "height range" into shades from 0 to 255 (black - white). The value set for the "height range" can be variable.

Fig. 7 schematically illustrates an example gray scale change process. In Fig. 7, the height range is controlled from 0 to 2 mm, and the change in gray scale is carried out on the basis of detailed information, such as a height of 1.0 mm in the area of ​​the shape profile line, a height of 0.4 mm in the inner area profile lines and a height of 0 mm in the area of ​​the outer profile line. If the height range from 0 to 2 is divided by a gray scale of 256 levels, the 1.0 mm high fragment will correspond to shade 128, the 0.4 mm high fragment - shade 51 and the 0 mm high fragment - shade 0 (black) .

Next, the shape deformation stage will be explained. The shape modeling device 11 deforms the image data for the shape in the manner described below based on the shape arrangement information (R, θ) recorded in the detailed shape information.

First, at a location located at a distance R from the center of the tire, as shown in Fig. 8, a sample of image data for the shape 24 shown in Fig. 8 is taken according to the sampling interval ΔR from the center of the tire in the radial direction and the sampling interval Δθ in the circumferential direction tires (stage 9). The sampling interval value can be variable.

Then the size deformation and the change of polar coordinates to rectangular coordinates are made in such a way that the intersection points are set at equal intervals to obtain the image data for the shape 26 shown in Fig. 8c (step 10). Fig. 9 schematically shows the change in size and polar coordinates to rectangular coordinates.

The deformation that the intersection points are set at equal intervals is carried out because it is not influenced by the size of the tire, and the master data can be used for different tire sizes. Since there is no need to create master data separately for different tire sizes, the present invention allows to minimize the amount of work involved in creating a master database.

The size of the shape image is controlled so that it matches the size of the quadrangle surrounding the area after deformation. As shown in Fig. 10, the image size becomes the dimension determined by the lateral dimension of the outer border (px) x the longitudinal direction of the outer border. The reference system (X, Y) constituting the reference shape system is defined in such a way that the lower left corner of the outer border is the reference point.

Image data obtained as described above are saved in basic data, e.g. in bitmap format.

Then a table is created containing additional information, such as image number, setting angle, setting diameter, setting reference point, image size, shape designation, back and front designation, file name etc. (step 11). Fig. 11 is an example table with additional information. The shape designation on the nameplate specifies the form number and type type, e.g. "Made in Japan". The front and back markings indicate, e.g. whether the shape is on one side or both sides.

Then, a basic database of the deformed shape is created in the manner described above and a table containing additional information (step 12).

The shape deformation process in the example described above is carried out after the gray scale change process, but the gray scale change process can also be carried out after the shape deformation process.

"ATENTOWA" BELLEPAT "LAW OFFICE

Izabela Szych ulska-Hawranek ul Słowackiego 44, 37-700 Przsntuśl tel. (016) 7 J2-37-77 fax: (016) 675-02-87 mobile phone (0608) 503-081 e-mati <a href="mailto:fcellepat@op.pl">fcellepat@op.pl</a> NIP: 795-207-16-72 REGON: 1803505 (6

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