A method, use and program product for extracting a profile of a tire footprint with a pattern groove

Abstract

The present application relates to the technical field of simulation design of tires, and particularly relates to a method for extracting a tire footprint contour with a pattern groove, an application and a program product. The method comprises the following steps: 1) obtaining node coordinate information of a tire model after deformation and corresponding ground pressure information; 2) performing refined interpolation on the ground pressure; 3) obtaining an isogram of a minimum pressure value; 4) triangulating coordinate points of a plurality of pattern blocks; 5) removing triangles connected with the pattern blocks and not contained in the pattern blocks; and 6) identifying convex edges of the remaining triangles. The present application realizes fast, accurate and standardized extraction of a tire footprint contour, obtains a contour of a footprint by using a geometric method, has the advantages of accurately identifying contour information of a simulation footprint, being able to define a minimum pressure value contained in a tire footprint, not needing a scale and being able to accurately obtain a footprint length at an arbitrary position outside a maximum length of the footprint.

Description

Technical Field

[0001] This invention relates to the field of tire simulation design technology, and in particular to a method, application, and program product for extracting the contour of tire contact patch marks with tread grooves. Background Technology

[0002] Tires are the only part of a vehicle that comes into contact with the road surface. Many of a vehicle's performance characteristics are achieved through the small contact patch between the tire and the road, such as braking, traction, and steering. Furthermore, tire rolling resistance, noise, and wear resistance are also related to the contact patch. Therefore, the contact patch has always been the first test item in tire performance evaluation, and its importance is self-evident. With the development of computers and computational mechanics, numerical simulation technology has been successfully applied to tire performance analysis and has become increasingly mature. Currently, numerical simulations of tire performance are primarily based on general-purpose commercial software systems, such as Abaqus, Ansys, and Marc. The post-processing capabilities of these commercial software programs can directly and easily obtain information such as the tire contact patch area and ground pressure distribution cloud map. However, other contact patch indicators cannot be accurately extracted, such as the contact patch parameters in patent US 2004 / 0112492 A1 and the literature "Research on Evaluation System and Method of Comprehensive Ground Performance of Radial Tires." Obtaining these indicators requires an accurate outline of the tire contact patch.

[0003] Patent CN202110003922.8 and the document "Application of Image Processing Technology in Tire Ground Contact Geometric Feature Measurement" propose a tire imprint extraction method based on image processing technology. However, this method is more suitable for contour recognition of actual tire test imprint images or simulated imprints on slick tires. The simulated imprints of tires with tread grooves are not perfectly straight at the longitudinal grooves, making it difficult to correctly identify the imprint contour using this method. Processing the longitudinal groove edges as straight lines would severely reduce accuracy. Besides the above method, no effective imprint contour recognition method has been found, especially for the recognition of simulated imprints from tires with longitudinal grooves. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the prior art, namely, that existing techniques are unsuitable for extracting the contours of simulated tire contact tracks. Processing the edges of the longitudinal grooves of the track as straight lines results in a significant loss of accuracy, and currently, there is no effective method for recognizing simulated tire contact track contours. Furthermore, general-purpose numerical simulation software can only provide a qualitative visual perception of tire contact track cloud images, failing to accurately provide quantitative parameter indicators and lacking a unified standard, which is detrimental to performance analysis and evaluation. Therefore, this invention provides a method for extracting the contours of tire contact track tracks with tread grooves, achieving rapid, accurate, and standardized extraction of tire contact track contours.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for extracting the contour of a tire contact patch with tread grooves, the method comprising the following steps:

[0007] 1) Obtain the node coordinates and corresponding ground pressure information of the tire model after deformation.

[0008] Read the tire numerical simulation result file and extract the node coordinate information of the surface nodes in the tire model that may come into contact with the road surface, including the node number. N i Nodes x i , y i Coordinate values ​​and node pressure values p i ;

[0009] 2) Refine the interpolation of grounding pressure.

[0010] Find all nodes in step 1). x i and y i The maximum and minimum values ​​are denoted as . x max , x min , y max , y min ,exist x min and x max The interval is divided into 500-2000 equal parts, and the new... x Value is denoted as nx k ,exist y min and y max The interval is divided into 500-2000 equal parts, and the new... y Value is denoted as ny k According to step 1) x i , y i and p i The coordinates are obtained using the bicubic interpolation method. nx k , ny k Point pressure value np k ;

[0011] 3) Obtain the contour line of minimum pressure value

[0012] The pressure value np obtained in step 2) k Take the minimum value np min The contour lines, the outline of which is the area where each groove contacts the ground;

[0013] 4) Triangulate the coordinates of multiple patterned blocks.

[0014] Extract the coordinates of all points that make up the contour lines of the common lines in step 3), and triangulate this set of points to obtain multiple non-overlapping triangles;

[0015] 5) Remove triangles that are connected to the pattern block but not contained within the pattern block.

[0016] Process the triangles obtained in step 4). Iterate through each triangle obtained in step 4. If all three vertices of the triangle are on the outline of a pattern block obtained in step 3), and the triangle is not contained within the outline of the pattern block, then delete the triangle; otherwise, keep the triangle.

[0017] 6) Identify the convex edges of the remaining triangles

[0018] The set of triangles obtained in step 5) is used to identify closed regions. The area of ​​each closed region is compared, and the polygon with the largest area is the outline of the tire contact mark.

[0019] Preferably, in step 2) x min and x max The interval is divided into 1000 equal parts. y min and y max The interval is divided into 1000 equal parts.

[0020] As a preferred option, np in step 3) min The value range is 20 kPa to 100 kPa.

[0021] As a preferred option, in step 4), the Bowyer-Watson algorithm is used to triangulate the point set.

[0022] Furthermore, this invention also discloses the application of the method in tire simulation calculations. Preferably, this application can accurately obtain the ground contact length and width values.

[0023] Furthermore, the present invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the method.

[0024] Furthermore, the present invention also discloses a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the method.

[0025] Furthermore, the present invention also discloses a computer program product, including a computer program or instructions that, when executed by a processor, implement the method.

[0026] This invention, by employing the above-mentioned technical solution, achieves rapid, accurate, and standardized extraction of tire contact mark contours. It obtains the contour of the contact mark using geometric methods, and has advantages such as accurately identifying the contour information of simulated marks, customizing the minimum pressure value contained in the tire marks, not requiring a ruler, and accurately obtaining the length of the mark at any position outside the maximum contact mark length. Attached Figure Description

[0027] Figure 1 This is a flowchart of the technology of this patent;

[0028] Figure 2 This is a schematic diagram of the surfaces and coordinate axes that may come into contact with the road surface in the tire model.

[0029] Figure 3 This includes the node numbers, coordinate information, and pressure values ​​for the surfaces in the tire model that may come into contact with the road surface.

[0030] Figure 4 Original pressure cloud map of simulated tire ground contact imprint;

[0031] Figure 5 The new node coordinates and pressure values ​​are obtained after interpolation;

[0032] Figure 6 Contour map of grounding imprint pattern blocks for identification (minimum value is 0.05 kPa);

[0033] Figure 7 The triangulated shape representing the coordinate points of the patterned block;

[0034] Figure 8 A schematic diagram showing that all three vertices of a triangle lie on the outline of a pattern block, but the triangle is not contained within the outline of the pattern block.

[0035] Figure 9 This is a schematic diagram for deleting triangles whose three vertices lie on the outline of a pattern block and are not contained within the outline of the pattern block.

[0036] Figure 10 Outline of tire contact patch for identification;

[0037] Figure 11 A schematic diagram showing the outline of the patterned block and the overall imprint outline;

[0038] Figure 12 This is used to query the length and width values ​​of the grounding imprint outline drawn in the CAD drawing, and to query the imprint at any location.

[0039] Figure 13 This is a grounding imprint profile diagram when the minimum pressure is set to 100 kPa. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the accompanying drawings: This embodiment is implemented based on the technical solution of the present invention and provides detailed implementation methods, but the protection scope of the present invention is not limited to the following embodiments.

[0041] like Figure 1 The method shown here is for extracting the contour of a tire contact patch with tread grooves. Taking an Abaqus calculation file of a 42550R18 tire as an example, the method includes the following steps:

[0042] (1) Obtain the node coordinate information and corresponding ground pressure information of the tire model after deformation. Read the tire numerical simulation results .dat file, and obtain the coordinate information of the surface nodes in the tire model that may come into contact with the road surface (e.g., Figure 2 Extract the node coordinate information of the surface nodes in the tire model that may come into contact with the road surface, including the node number. N i Nodes x i , y i Coordinate values ​​and node pressure values p i ,like Figure 3 The simulation results show that the imprint is as follows Figure 4 As shown.

[0043] (2) Refine the interpolation of the grounding pressure. Find the values ​​of all nodes in the first step. x i and y i The maximum and minimum values ​​are x max =128.25476 , x min =-128.30043 , y max =107.91931 ,y min =-107.91294 ,exist x min and x max The interval is divided into 1000 equal parts, and the new... x Value is denoted as nx k ,exist y min and y max The interval is divided into 1000 equal parts, and the new... y Value is denoted as ny k According to the first step x i , y i and p i The coordinates are obtained using the bicubic interpolation method. nx k , ny k Point pressure value np k ,like Figure 5 .

[0044] (3) Obtain the contour line of the minimum pressure value. Since the pressure blanket sensor in actual tire testing has a minimum detection accuracy, generally ranging from 20kPa to 100kPa, the pressure value np obtained in the second step is typically used to align with the actual test results. k Take the minimum value np min The contour lines are defined by a pressure of 0.05 MPa (i.e., 50 kPa) (with values ​​ranging from 20 kPa to 100 kPa). The outline of these contour lines represents the contact area between each groove and the ground. Figure 6 .

[0045] (4) Triangulate the coordinates of multiple patterned blocks. Extract the coordinates of all points that make up the contour lines in step three, and use the Bowyer-Watson algorithm to triangulate this point set to obtain multiple non-overlapping triangles, such as... Figure 7 .

[0046] (5) Remove triangles that are connected to the pattern block but not contained within it. Process the triangles obtained in step four. Iterate through each triangle obtained in step four. If all three vertices of a triangle lie on the outline of a pattern block obtained in step three, and the triangle is not contained within the outline of the pattern block, such as... Figure 8 If the triangle is not found, delete it; otherwise, keep it. The final set of triangles obtained is as follows: Figure 9 As shown.

[0047] (6) Identify the convex edges of the remaining triangles. Identify closed regions in the triangle set obtained in step five, compare the area of ​​each closed region, and the polygon with the largest area is the outline of the tire contact patch, such as... Figure 10 As shown, the outline of the patterned block and the entire imprint outline are drawn simultaneously, as follows: Figure 11 .

[0048] The above method allows for the extraction of the tire contact patch outline with tread grooves, facilitating comparison with experimental test results and tire design evaluation. Using this patented method, the contact patch length and width values ​​are accurately obtained as 182.27 mm and 226.96 mm, respectively. The error compared to experimental test results (with a detection accuracy of 50 kPa) is less than 1 mm. However, if the colored areas are assigned according to the Abaqus cloud map, the contact patch length and width are 186.2 mm and 229.6 mm, respectively, which differs from the maximum experimental result by nearly 4 mm. Furthermore, this patented method has obtained the coordinates of each point on the contact patch outline, which can be plotted in a CAD drawing for querying the length and width values ​​of the patch at any location. Figure 12 Using the aforementioned method, the grounding imprint profile is set to a minimum pressure of 100 kPa as shown below. Figure 13 As shown, the width is 226.4mm and the length is 174.7mm.

[0049] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A method for extracting the contour of a tire contact patch with tread grooves, characterized in that, The method includes the following steps: 1) Obtain the node coordinates and corresponding ground pressure information of the tire model after deformation. Read the tire numerical simulation result file and extract the node coordinate information of the surface nodes in the tire model that may come into contact with the road surface, including the node number. N i Nodes x i , y i Coordinate values ​​and node pressure values p i ; 2) Refine the interpolation of grounding pressure. Find all nodes in step 1). x i and y i The maximum and minimum values ​​are denoted as . x max , x min , y max , y min ,exist x min and x max The interval is divided into 500-2000 equal parts, and the new... x Value is denoted as nx k ,exist y min and y max The interval is divided into 500-2000 equal parts, and the new... y Value is denoted as ny k According to step 1) x i , y i and p i The coordinates are obtained using the bicubic interpolation method. nx k , ny k Point pressure value np k ; 3) Obtain the contour line of minimum pressure value The pressure value np obtained in step 2) k Take the minimum value np min The contour lines, the outline of which is the area where each groove contacts the ground; 4) Triangulate the coordinates of multiple patterned blocks. Extract the coordinates of all points that make up the contour lines of the common lines in step 3), and triangulate this set of points to obtain multiple non-overlapping triangles; 5) Remove triangles that are connected to the pattern block but not contained within the pattern block. Process the triangles obtained in step 4). Iterate through each triangle obtained in step 4. If all three vertices of the triangle are on the outline of a pattern block obtained in step 3), and the triangle is not contained within the outline of the pattern block, then delete the triangle; otherwise, keep the triangle. 6) Identify the convex edges of the remaining triangles The set of triangles obtained in step 5) is used to identify closed regions. The area of ​​each closed region is compared, and the polygon with the largest area is the outline of the tire contact mark.

2. The method for extracting the contour of a tire contact patch with tread grooves according to claim 1, characterized in that, In step 2) x min and x max The interval is divided into 1000 equal parts. y min and y max The interval is divided into 1000 equal parts.

3. The method for extracting the contour of a tire contact patch with tread grooves according to claim 1, characterized in that, Step 3) np min The value range is 20 kPa to 100 kPa.

4. The method for extracting the contour of a tire contact patch with tread grooves according to claim 1, characterized in that, In step 4), the Bowyer-Watson algorithm is used to triangulate the point set.

5. The application of the method described in any one of claims 1-4 in tire simulation calculations.

6. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the method according to any one of claims 1-4.

7. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the method described in any one of claims 1-4.

8. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by a processor, they implement the method described in any one of claims 1-5.

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