KR102684232B1 - A method of visualizing the footshape of a tire using the design of experiment method - Google Patents

Abstract

The present invention includes the steps of (a) structurally analyzing a plurality of virtual tires, (b) setting a reference virtual tire as a standard among the plurality of virtual tires, and (c) extracting the contact field characteristics for each rib from the reference virtual tire. Step, (d) reflecting a preset ratio to the contact length and contact width of the reference virtual tire based on the contact length characteristics, and (e) visualizing the contact shape of the reference virtual tire according to the rib change of the reference virtual tire. Provides a method for visualizing the grounding shape of a tire using an experimental design method comprising:

Description

A method of visualizing the footshape of a tire using the design of experiment method}

The present invention relates to a method for visualizing the contact shape of a tire using a design of experiment method, and more specifically, to a method for visualizing the contact shape of a tire using a design of experiment method for visualizing the contact shape of a tire.

In order to improve the performance of tires, there is a method of producing a prototype and then conducting testing, but this method has the disadvantage of requiring a new prototype to be produced each time a test is conducted.

Accordingly, research and development is being actively conducted on technology to virtually model tires in three dimensions and then simulate tire performance through structural or dynamic analysis.

Figure 1 is a diagram showing the results of quantifying the ground shape obtained using a design of experiment (DOE) method according to the prior art.

A technique for confirming the grounding shape of a tire through the above simulation is shown in FIG. 1.

The currently used design of experiment (DOE) system shown in Figure 1 is when looking at the tread from the tire, center, 25% of the center, 75% of the center Length, Width, and Square By deriving design of experiment (DOE) regression equations for ground shape characteristics (numerical results) such as Ratio, Roundness, Actual Contact Area, and Total Contact Area, It can be used for prediction.

Figure 2 is a diagram showing that the design of experiment (DOE) according to the prior art is unable to visualize the ground shape.

However, the ground shape characteristics derived using the above-mentioned experimental design method can only be confirmed as numerical values according to changes in design factors as shown in FIG. 1, and it is impossible to visualize them intuitively as shown in FIG. 2. There was a problem where intuitive evaluation of the ground shape was impossible.

(Patent Document 1) Japanese Patent Publication No. 2021-081246 (2021.05.27.)

The purpose of the present invention to solve the above problems is to perform 3D modeling and structural analysis on a number of virtual tires to obtain each design factor, and then determine the grounding shape of the tire to be visualized among each design factor. It provides a method of visualizing the grounding shape of a tire using a design of experiment method that visualizes the grounding shape of a tire for an arbitrary design factor by expanding or reducing the grounding shape for an arbitrary design factor and adjacent design factors.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

The configuration of the present invention to achieve the above object includes (a) structural analysis of a plurality of virtual tires; (b) setting a reference virtual tire as a standard among the plurality of virtual tires; (c) extracting the contact field for each rib from the plurality of virtual tires; (d) reflecting a preset ratio to the contact length and contact width of the reference virtual tire based on the contact length for each rib in the plurality of virtual tires; and (e) visualizing the contact shape of the tire according to the rib change of the reference virtual tire.

In an embodiment of the present invention, step (a) includes: (a1) three-dimensional modeling the plurality of virtual tires; and (a2) structurally analyzing the plurality of 3D modeled virtual tires.

In an embodiment of the present invention, step (b) includes: (b1) obtaining a plurality of design factors for each of the plurality of virtual tires from the results of structural analysis of the plurality of virtual tires; (b2) setting a design factor adjacent to any design factor for the ground shape to be visualized among the plurality of design factors; and (b3) setting a virtual tire for a design factor adjacent to the arbitrary design factor among the plurality of virtual tires as the reference virtual tire.

In an embodiment of the present invention, step (c) includes: (c1) setting ground contact extraction positions for the plurality of virtual tires; (c2) filtering noise generated at the ends of ribs for each ground field extraction location by fitting the ground field extraction location; (c3) extracting the contact field for each rib from the plurality of virtual tires; And (c4) extracting a regression equation for expanding and reducing the contact length and contact width of the plurality of virtual tires based on the contact length for each rib, wherein the contact length extraction location is the plurality of virtual tires. A first position located at the end of the rib bisecting the width direction, a second position spaced a predetermined distance in one direction from the first position, and a third position spaced a predetermined distance in the other direction from the first position. You can do this.

In an embodiment of the present invention, the step (d) includes: (d1) expanding or reducing the contact field in the y-axis direction by multiplying the xy coordinates of the contact field among the contact shape of the reference virtual tire by a preset contact equipment ratio. ; and (d2) expanding or reducing the contact width in the x-axis direction by multiplying the contact width xy coordinates of the contact shape of the reference virtual tire by a preset contact width ratio.

The effect of the present invention according to the above configuration is to perform 3D modeling and structural analysis on a plurality of virtual tires to obtain each design factor, and then select a random grounding shape of the tire to be visualized among each design factor. Intuitive evaluation is possible by visualizing the grounding shape of the tire for any design factor by expanding or reducing the grounding shape for the design factor and adjacent design factors.

The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

Figure 1 is a diagram showing the results of quantifying the ground shape obtained using a design of experiment (DOE) method according to the prior art.
Figure 2 is a diagram showing that the design of experiment (DOE) method according to the prior art is unable to visualize the ground shape.
Figure 3 is a flowchart showing a method for visualizing the contact shape of a tire using a design of experiment method according to an embodiment of the present invention.
Figure 4 is a diagram showing design factors derived by structural analysis of a number of virtual tires in a tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figure 5 is a diagram showing arbitrary design factors and a number of design factors for a number of virtual tires displayed as positions in three-dimensional space in the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention. .
Figure 6 is a diagram showing the extraction locations of the contact fields of multiple virtual tires in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figure 7 is a diagram showing noise removed by fitting the ground extraction location in the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figure 8 is a diagram showing the process of fitting the ground extraction location in the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figures 9 (a) and (b) are diagrams visually showing the results of printing a reference virtual tire excluding errors in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figure 10 is an image showing CNTLENofRIB, where the grounding length results for each rib are stored in the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figure 11 is an image showing the center of the grounding shape in text in the method of visualizing the grounding shape of a tire using the design of experiment method according to an embodiment of the present invention.
Figure 12 is an image showing R-squared to confirm the reliability of the regression equation extracted from the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figures 13 (a) and (b) are diagrams showing the process of expanding or reducing the contact field in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figures 14 (a) and (b) are diagrams showing the process of expanding or reducing the contact width in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figures 15 (a), (b), and (c) are diagrams showing the process of adjusting the end rib width in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figure 16 is a diagram showing correction of the total length of the contact width in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention.
Figure 17 is a diagram showing the analysis results of the ground shape visualized through the tire ground shape visualization method using the design of experiment method according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention may be implemented in various different forms and, therefore, is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this means not only "directly connected" but also "indirectly connected" with another member in between. "Includes cases where it is. Additionally, when a part is said to “include” a certain component, this does not mean that other components are excluded, but that other components can be added, unless specifically stated to the contrary.

The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.
The term “rib” used throughout the specification of the present invention refers to a plurality of grooves (FIGS. 2, 4, and 5) formed in the driving direction (up and down in FIGS. 2, 4, and 5) when the tire touches the ground. The tire is divided by the vertical white lines in FIG. 5, which means each divided ground shape among the ground shapes of the tire shown in FIGS. 2, 4, and 5.
Additionally, the term “ground length” used throughout the specification of the present invention refers to the length in the vertical direction (y-axis direction) of each rib shown in FIGS. 2, 4, and 5.
Additionally, the term “ground width” used throughout the specification of the present invention refers to the length in the left and right direction (x-axis direction) of each rib shown in FIGS. 2, 4, and 5.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

Figure 3 is a flowchart showing a method for visualizing the contact shape of a tire using a design of experiment method according to an embodiment of the present invention.

The method for visualizing the grounding shape of a tire using the design of experiment method according to an embodiment of the present invention visualizes the grounding shape by supplementing the design of experiment method that extracts the grounding shape only numerically, and is not defined other than a number of design factors for a number of virtual tires. It is also intended to visualize the ground shape for arbitrary design factors (3D positions) that are not specified.

Referring to Figure 3, the method for visualizing the grounding shape of a tire using the design of experiment method according to an embodiment of the present invention for this purpose includes (a) structural analysis of a plurality of virtual tires (S100), (b) a plurality of virtual tires (S200), (c) extracting the contact field for each rib from multiple virtual tires (S300), (d) based on the contact field for each rib from multiple virtual tires, It includes the step of reflecting a preset ratio to the contact length and contact width of the reference virtual tire (S400) and (e) visualizing the contact shape of the tire according to the rib change of the reference virtual tire (S500).

Figure 4 is a diagram showing design factors derived by structural analysis of a number of virtual tires in a tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention.

Referring to FIG. 4, step (a) includes the steps of (a1) 3D modeling a plurality of virtual tires and (a2) structurally analyzing the 3D modeled plurality of virtual tires.

Specifically, in step (a1), 17 virtual tires are modeled in three dimensions.

Next, in step (a2), structural analysis is performed on 17 virtual tires, and the results of the structural analysis are shown in FIG. 4.

Figure 5 is a diagram showing arbitrary design factors and a number of design factors for a number of virtual tires displayed as positions in three-dimensional space in the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention. .

Referring to FIG. 5, step (b) includes (b1) obtaining a plurality of design factors for a plurality of virtual tires from the results of structural analysis of the plurality of virtual tires, (b2) among the plurality of design factors. It includes the step of setting a design factor adjacent to a random design factor for the ground shape to be visualized, and (b3) setting a virtual tire for a design factor adjacent to a random design factor among a plurality of virtual tires as a reference virtual tire. do.

Specifically, in step (b1), as shown in FIG. 4, 17 design factors (var1=x, var2=y, var3=z) are derived from the results of structural analysis of 17 virtual tires.

Here, the design factors may be mechanical characteristics that specify the outer shape of the tire, dimensions of the structure (=size, dimensions, etc.), and boundary conditions for performing structural analysis (e.g., load, location of applied load, etc.) .

Next, in step (b2), undefined arbitrary design factors are set in addition to the 17 design factors obtained in step (b1).

Specifically, the blue dot shown in Figure 5 represents three design factors (var1=x, var2=y, var3=z) as coordinates in three-dimensional space, and each design factor for 17 virtual tires is shown. It is done.

That is, in the three-dimensional space, there are countless undefined coordinates in addition to the 17 coordinates, and among these, arbitrary design factors to be implemented are indicated by X in FIG. 5.

Therefore, in step (b2), the coordinate closest to the coordinate corresponding to an arbitrary design factor among the 17 coordinates is set.

Next, in step (b3), a virtual tire for a design factor adjacent to a random design factor among a plurality of virtual tires is set as a reference virtual tire.

For example, if the virtual tire for a design factor adjacent to any design factor among the 17 virtual tires shown in FIG. 3 is the virtual tire shown on the leftmost, that virtual tire is set as the reference virtual tire.

Figure 6 is a diagram showing the extraction position of the contact field of a reference virtual tire in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention. Figure 7 is a diagram showing noise removed by fitting the ground extraction location in the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention. Figure 8 is a diagram showing the process of fitting the ground extraction location in the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention.

Referring to Figures 6 to 8, step (c) includes (c1) setting the grounding field extraction positions for a plurality of virtual tires, (c2) fitting the grounding field extraction positions to extract the ribs for each grounding field extraction position. (c3) extracting the grounding field for each rib from multiple virtual tires, and (c4) extracting the grounding field for each rib from the multiple virtual tires. and a step of extracting a regression equation for expanding and reducing the ground width.

Referring to FIG. 6, in step (c1), the contact field extraction position is a first position (star located in the center) located at the end of a rib bisecting a plurality of virtual tires in the width direction, in one direction from the first position. It is defined as a second position spaced a predetermined distance away (a star located to the left of the first position) and a third position spaced a predetermined distance away from the first position in the other direction (a star located to the right of the first position).

In more detail, in the state shown in FIG. 6, a first reference line bisecting a plurality of virtual tires is set, and the point where the first reference line meets the upper end of the reference virtual tire is defined as the first position.

In addition, in the state shown in FIG. 6, the point where the upper end of the reference virtual line and the second reference line spaced 5 grids to the left from the first reference line meet is defined as the second position.

In addition, in the state shown in FIG. 6, the point where the upper end of the reference virtual line and the third reference line spaced 5 grids to the right from the first reference line meet is defined as the third position.

Next, referring to FIG. 7, in step (c2), noise is removed by fitting (using the fifth-order equation) based on the first to third positions so that the upper end of the reference virtual tire is gentle without any protruding parts. do.

Specifically, in (a) of Figure 8, the upper end of the center rib located in the center is expressed as a set of points, and in step (c2), the upper end of the center rib located on the left and right away from the set of points in (a) of Figure 8 Remove dots (remove noise).

In the same manner, in step (c2), points that are apart from the set of points in (b) and (c) of Figure 8 are removed (noise removed).

Figures 9 (a) and (b) are diagrams visually showing the results of printing a reference virtual tire excluding errors in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention.

Only when an error does not occur, the output is output as shown in (a) and (b) of FIG. 9.

Figure 10 is an image showing CNTLENofRIB in which the grounding length results for each rib are stored in the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention.

The ground field results for each rib (center rib, first rib, second rib, side tread) are stored in CNTLENofRIB shown in FIG. 10.

Figure 11 is an image showing the center of the grounding shape in text in the method of visualizing the grounding shape of a tire using the design of experiment method according to an embodiment of the present invention.

Additionally, data about the center of the ground shape is output as text, as shown in FIG. 11.

Figure 12 is an image showing R-squared to confirm the reliability of the regression equation extracted from the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention.

In the present invention, regression equations for expansion and contraction of the ground field and ground width are automatically extracted through design of experiment (DOE).

At this time, in order to examine the reliability of the extracted regression equation, the results of extracting values based on the rib position are shown in FIG. 12.

Referring to FIG. 12, it can be seen that the reliability of the R-squared value has been improved to a level that can be used to adjust the overall ground shape.

Figures 13 (a) and (b) are diagrams showing the process of expanding or reducing the contact field in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention. Figures 14 (a) and (b) are diagrams showing the process of expanding or reducing the contact width in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention. Figures 15 (a), (b), and (c) are diagrams showing the process of adjusting the end rib width in the tire grounding shape visualization method using the design of experiment method according to an embodiment of the present invention. Figure 16 is a diagram showing correction of the total length of the contact width in the tire contact shape visualization method using the design of experiment method according to an embodiment of the present invention.

Next, referring to FIGS. 13 to 16, step (d) includes (d1) multiplying the xy coordinates of the grounding field among the grounding shape of the reference virtual tire by a preset grounding equipment ratio to expand or contract the grounding field in the y-axis direction. Step (d2) includes expanding or reducing the contact width in the x-axis direction by multiplying the contact width xy coordinates of the contact shape of the reference virtual tire by a preset contact width ratio.

Specifically, referring to (a) of FIG. 13, in step (d1), a plurality of xy coordinates (x, y) forming the grounding field are multiplied by a preset grounding equipment ratio, and accordingly, a plurality of xy coordinates (x, y) ) The gap between them decreases or increases, but the gap is filled during the process of spraying the contour.

Here, the preset grounding equipment ratio is 1.5, and even if multiple xy coordinates are multiplied by the preset grounding equipment ratio, in the case of a grounding field, all ribs are based on the x-axis reference line (Y=0) as shown in (b) of Figure 13. As a result, the ribs (center rib, first rib, second rib, side tread) are expanded or contracted only in the y-axis direction as only the Y value is multiplied by the preset grounding equipment ratio.

Meanwhile, in the case of the grounding width, unlike the grounding length, in the case of the x value, the reference position of all ribs is not 0, so not only does the rib reference position change when expanded, but even if only the Since the coordinate position is multiplied by the preset ground width ratio, as shown in FIG. 14, in the process of expanding or contracting the rib, a phenomenon (red line) that invades another position occurs.

Accordingly, in the case of a grounding shape, even when the grounding width changes, the width of the inner ribs and grooves generally do not change, so it is necessary to adjust the end ribs by the amount of the grounding width change.

In order to fix the reference position of the end rib but expand it outward, set the local coordinates of the inside of the end rib to the X = 0 coordinate ((a) in Figure 15) and then proceed to expand or contract the rib. After ((b) in Figure 15), proceed by adding back to the x value of the corresponding ribs the amount subtracted to make the x position of the inner rib to 0 using [Equation 1] below ((c) in Figure 15) )do.

[Equation 1]

X_Rib1=ratio_rib1*X_Rib1

In addition, the amount by which the total width (length in the horizontal direction) of the grounding shape shown in Figure 16 increases (1.5 cm on both sides) is converted into the amount of end rib expansion. At this time, due to the nature of expanding or contracting the grid, It is necessary to multiply by the preset overall correction ratio.

Here, the width (a) of the expanded grounding shape shown in FIG. 16, the overall width (b) of the grounding shape, the width (c) of the side tread, and the preset overall correction ratio (ratio) are expressed in [Equation 2] below. It is defined as follows.

[Equation 2]

At this time, referring to Figure 16, Since d, the width of the side tread (c), the expanded width of the side tread (d), and the preset overall correction ratio (ratio) are finally defined as in [Equation 3] below.

[Equation 3]

d=ratio*c

Figure 17 is a diagram showing the analysis results of the ground shape visualized through the tire ground shape visualization method using the design of experiment method according to an embodiment of the present invention.

The analysis results in which the grounding shape for arbitrary design factors is visualized through the above-described process are shown in FIG. 17.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as single may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the patent claims described below, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

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Claims (5)

(a) Structural analysis of multiple virtual tires;
(b) setting a reference virtual tire as a standard among the plurality of virtual tires;
(c) extracting the contact field for each rib from the plurality of virtual tires;
(d) reflecting a preset ratio to the contact length and contact width of the reference virtual tire based on the contact length for each rib in the plurality of virtual tires; and
(e) visualizing the contact shape of the tire according to the rib change of the reference virtual tire; a method for visualizing the contact shape of a tire using a design of experiment method, comprising:
According to claim 1,
In step (a),
(a1) 3D modeling the plurality of virtual tires; and
(a2) A method of visualizing the grounding shape of a tire using a design of experiment method, comprising: structurally analyzing the plurality of 3D modeled virtual tires.
According to claim 1,
In step (b),
(b1) obtaining a plurality of design factors for each of the plurality of virtual tires from the results of structural analysis of the plurality of virtual tires;
(b2) setting a design factor adjacent to any design factor for the ground shape to be visualized among the plurality of design factors; and
(b3) setting a virtual tire for a design factor adjacent to the random design factor among the plurality of virtual tires as the reference virtual tire; a method for visualizing the grounding shape of a tire using a design of experiment method, comprising:
According to claim 1,
In step (c),
(c1) setting a grounding field extraction position for the plurality of virtual tires;
(c2) filtering noise generated at the ends of ribs for each ground field extraction location by fitting the ground field extraction location;
(c3) extracting the contact field for each rib from the plurality of virtual tires; and
(c4) extracting a regression equation for expanding and reducing the contact length and contact width of the plurality of virtual tires based on the contact length for each rib in the plurality of virtual tires,
The contact field extraction position is a first position located at the end of a rib that bisects the plurality of virtual tires in the width direction, a second position spaced a predetermined distance away from the first position in one direction, and a second position in the other direction from the first position. A method of visualizing the grounding shape of a tire using a design of experiment method, characterized in that the third position is spaced a predetermined distance apart.
According to claim 1,
In step (d),
(d1) expanding or reducing the grounding field in the y-axis direction by multiplying the xy coordinates of the grounding field among the grounding shape of the reference virtual tire by a preset grounding equipment ratio; and
(d2) expanding or reducing the contact width in the x-axis direction by multiplying the contact width xy coordinates of the contact shape of the reference virtual tire by a preset contact width ratio; Ground shape visualization method.

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