A method, system and computer program product for obtaining actual material distribution map of a tire

Abstract

The present invention relates to the technical field of tire simulation design, and in particular to a method, system and computer program product for obtaining an actual material distribution map of a tire. The method scans the outer contour of the actual tire, combines it with the material distribution map of the tire cross section, and uses smoothing and affine transformation technology to accurately match the outer contour and the material distribution map. The specific steps include scanning the outer contour of the tire, drawing the material distribution map, smoothing the contour, selecting and equally dividing the mapping curve, calculating the affine transformation matrix, dividing the material distribution map into multiple small areas, and performing affine transformation on the small areas to generate the actual material distribution map. The present invention significantly improves the simulation accuracy, shortens the correction time, and is applicable to a variety of tire models and complex structures. The material distribution map generated by this method can provide accurate data support for performance optimization such as tire rolling resistance and force analysis, and has wide application value.

Description

Technical Field

[0001] The present invention relates to the technical field of tire simulation design, and in particular to a method, system and computer program product for obtaining an actual material distribution map of a tire. Background Art

[0002] Tires are complex composite structures whose performance is directly influenced by material distribution and structural properties. However, due to variations in process parameters, material properties, and component dimensions during the manufacturing process, the material distribution and geometry of produced tires often deviate significantly from the designed prototype. Existing tire performance simulation and analysis methods typically use mold design contours for modeling, but this approach struggles to accurately reflect the material distribution and structural properties of the actual tire, resulting in significant discrepancies between simulation results and actual performance.

[0003] While some existing technologies attempt to modify design models using actual tire cross-sections, these methods typically only adjust the thickness of internal components, leaving the outer contour based on the mold design. This type of correction not only struggles to improve the overall accuracy of the simulation model, but also suffers from the time-consuming adjustment process. Chinese invention patents filed by the applicant (such as Patent 2021116135564, Patent 2022100923567, and Patent 2022105620611) propose several simulation analysis methods for tire performance, but none of them address the discrepancy between actual material distribution and the design model. Summary of the Invention

[0004] To address the aforementioned technical issues, this paper proposes a method for obtaining actual material distribution maps for tire performance analysis. By incorporating affine transformation technology, the cross-sectional material distribution of the actual tire is precisely matched with the outer profile data, thereby quickly and accurately generating a material distribution map consistent with the actual tire. This method significantly improves the accuracy of performance simulation analysis and provides more reliable data support for tire design and optimization.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0006] A method for obtaining an actual material distribution map for tire performance analysis, characterized by comprising the following steps:

[0007] 1) External contour scanning: Inflate the tire to standard pressure, then deflate it to an internal pressure of 0.01-0.1 MPa. Use a laser scanner to obtain the tire's external contour and save it as a vector file.

[0008] 2) Material distribution map drawing: Based on the actual tire cross section, use CAD software to draw the tire material distribution map;

[0009] 3) Outer contour smoothing: Smoothing the outer contour data to eliminate the roughness and obtain a smoothed outer contour curve;

[0010] 4) Material distribution map smoothing: Smoothing the outer contour of the drawn material distribution map to obtain a smoothed material distribution map curve;

[0011] 5) Mapping curve selection and equal division: Select some continuous curves from the smoothed outer contour curve and material distribution curve respectively and divide them into equal parts. The number of equal divisions is n, and generate the target curve set and the original curve set.

[0012] 6) Affine transformation matrix calculation: Calculate the affine transformation matrix based on the target curve node coordinates and the original curve node coordinates;

[0013] 7) Region division: Generate multiple small regions according to the equally divided points based on the mapping curve;

[0014] 8) Affine transformation: Perform affine transformation on the point coordinates of each small area and update them to the point coordinates of the actual material distribution map.

[0015] Preferably, the outer contour smoothing process in step 4) includes:

[0016] a) Use arc to block the concave part of the groove;

[0017] b) Use arcs to smooth out the rough curves caused by grooves, decorative lines and font lines.

[0018] Preferably, the affine transformation matrix in step 6) is calculated by the following formula:

[0019]

[0020] in x * k , y* k represents the coordinates of the points on the original curve, x k and y k Represents the coordinates of the point on the target curve, a k , b k , c k , d k , p k , q k are the affine transformation coefficients.

[0021] Preferably, in step 7), the principle of equally dividing the mapping curve is that the length of each curve portion is no more than 0.5 mm, and the number of equally divided portions n is an even number and greater than 30.

[0022] Preferably, the affine transformation in step 8) is calculated by the following formula:

[0023]

[0024] in x * m , y* m represents the coordinates of the points on the original curve, x m and y m Represents the coordinates of the point on the target curve, a m , b m , c m , d m , p m , q m are the affine transformation coefficients.

[0025] Furthermore, the present invention also provides a system for obtaining an actual material distribution map of a tire, wherein the system implements the method, including:

[0026] Laser scanning module: used to scan the outer contour of the tire and generate a vector file containing the outer contour data;

[0027] Drawing module: used to import actual cross-section images and draw tire material distribution maps;

[0028] Smoothing module: smoothing the tire outer contour and material distribution map;

[0029] Affine transformation module: used to calculate the affine transformation matrix and perform affine transformation operations on small areas;

[0030] Segmentation module: used to segment the material distribution map into multiple small areas according to the mapping curve;

[0031] Output module: Outputs the updated actual material distribution map.

[0032] Preferably, the affine transformation module includes:

[0033] The node extraction submodule is used to extract the coordinates of equally divided nodes of the mapping curve;

[0034] Matrix calculation submodule, used to calculate the affine transformation matrix based on the node coordinates;

[0035] The coordinate transformation submodule is used to perform coordinate affine transformation of a small area.

[0036] As a preference, the output module can export the updated material distribution map into multiple formats, including dxf, svg or other compatible formats, to facilitate subsequent simulation analysis.

[0037] Furthermore, the present invention also provides a computer-readable storage medium having a computer program or instruction stored thereon, which implements the method when the computer program or instruction is executed by a processor.

[0038] Furthermore, the present invention also provides a computer program product, comprising a computer program or instructions, which implement the method when executed by a processor.

[0039] By adopting the above-mentioned technical solution, the present invention proposes a method and system for obtaining an actual material distribution map for tire performance analysis. By introducing affine transformation technology, the actual tire cross-sectional material distribution is precisely matched with the outer contour data, thereby quickly and accurately generating a material distribution map consistent with the actual tire. This effectively solves the problem of discrepancies between simulation models and actual tire structures in the prior art, achieving the following technical effects:

[0040] 1. Improved Simulation Accuracy: By introducing affine transformation technology, the cross-sectional material distribution of the actual tire is precisely matched to the outer contour data, resulting in a material distribution map that more closely matches the actual tire structure. Compared to existing simulation analysis based on mold contours, the simulation results generated by this method are more consistent with actual test data, significantly improving the accuracy of performance analysis.

[0041] 2. Optimize the structural restoration process: The present invention simultaneously smoothes the outer contour and material distribution map, eliminating structural interference factors such as grooves, decorative lines and fonts, thereby improving the smoothness and consistency of the curve and ensuring the overall accuracy of the simulation model.

[0042] 3. Shorten correction time: Through region segmentation and independent affine transformation, the present invention avoids the tedious process of traditional methods of point-by-point correction of tire sections, realizes the rapid generation of material distribution maps, and significantly reduces the time required for tire simulation modeling.

[0043] 4. Enhanced modeling flexibility: The method of the present invention supports regional processing of complex geometric structures of tires, and the affine transformation parameters between each region can be calculated independently, so that the method can adapt to the modeling requirements of tires of different models, sizes and complex structures.

[0044] 5. Improved Application Value: Utilizing the actual material distribution maps generated by this method makes subsequent simulation analysis more reliable, providing a more accurate data foundation for performance optimization, such as tire rolling resistance and pinning force analysis. This not only improves tire product design efficiency but also provides important technical support for quality control and performance optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Scan the outer contour of the tire;

[0046] Figure 2 It is the actual cross-sectional image of the tire;

[0047] Figure 3 It is a material distribution map drawn based on the actual cross section;

[0048] Figure 4 For smoothing of the scanned outer contour;

[0049] Figure 5 For smoothing of tread grooves;

[0050] Figure 6 Smoothing of contour fluctuations caused by decorative buttons or fonts;

[0051] Figure 7 The contour scanned graphics after smoothing;

[0052] Figure 8 This is the tire material distribution diagram after smoothing;

[0053] Figure 9 is the mapping target curve on the S_S_P contour;

[0054] Figure 10 is the original curve mapped on the S_M_P contour;

[0055] Figure 11 Calculate the result for the affine matrix;

[0056] Figure 12 Schematic diagram of segmentation processing of contour map;

[0057] Figure 13 The final contour map is consistent with the scanned outer contour;

[0058] Figure 14 To compare the simulation analysis profile using the mold profile with the actual measurement;

[0059] Figure 15 The simulation analysis performed on the transformed contour is compared with the actual measurement. DETAILED DESCRIPTION

[0060] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0061] This invention proposes a method for obtaining an actual material distribution map for tire performance analysis. By introducing affine transformation technology, the actual tire cross-sectional material distribution is precisely matched with the outer contour data, thereby quickly and accurately generating a material distribution map consistent with the actual tire. Specifically, the method includes the following steps:

[0062] Step 1: Inflate the tire to the standard pressure, then deflate it until the internal pressure is 0.05 MPa. Use a laser scanner to scan the outer contour of the tire, denoted as O_S_P, to obtain a dxf file containing the outer contour of the tire.

[0063] Step 2: Import the image into CAD software and draw the material distribution map of the tire according to the actual cross-section. This map is recorded as O_M_P. This material distribution map is the material distribution map of the cut tire cross-section. It is in a relaxed state and has a large difference from the actual tire profile.

[0064] Step 3: Smooth the tire's outer contour. Because the actual tire's outer contour includes elements such as tread grooves, decorative lines, and fonts, which can cause unevenness in the O_S_P line, it needs to be manually processed into a smooth curve. For tread grooves, use smooth arcs to block the concave portions. For unevenness caused by decorative lines and fonts, use arcs to smooth them. The final smoothed curve is recorded as S_S_P.

[0065] Step 4: Smooth the outer contour curve of the tire material distribution map. The actual tire material distribution map also has uneven curves caused by grooves, decorative lines, and font lines. Similarly, the material distribution map needs to be smoothed in the same way as in step 3. The final smoothed curve is recorded as S_M_P.

[0066] Step 5: Select the curve set to be mapped. Select a continuous curve on the S_S_P contour as the target curve for mapping and divide it into equal parts. The principle of equal division is that each part is no longer than 0.5mm. The number of equal divisions is n (n>30, and n is an even number). The target curve after equal division is recorded as M_S_P. Select a continuous curve on the S_M_P contour as the original curve for mapping. Divide it into equal parts again. The number of equal divisions is also n. The target curve after equal division is recorded as M_M_P.

[0067] Step 6: Extract the node coordinates on M_S_P in counterclockwise order, recorded as MSP j , where j = 0 ~ n. Similarly, extract the node coordinates on M_M_P in counterclockwise order, denoted as MMP i , where i=0~n, take out the nodes in turn (MSP 2k , MSP 2k+1 , MSP 2k+2 ) coordinates, and nodes (MMP 2k , MMP 2k+1 , MMP 2k+2 ) coordinates, where k = (0, n / 2-1), according to (MSP 2k , MSP 2k+1 , MSP 2k+2 ) and (MMP 2k , MMP 2k+1 , MMP 2k+2 ) The coordinates of the six nodes are calculated according to the following formula to calculate the affine transformation matrix:

[0068] (1)

[0069] in x * k , y* k represents the coordinates of the points on the M_S_P curve, x k and y k represents the coordinates of the points on the M_M_P curve, a k , b k , c k , d k , p k , q k These coefficients include translation, scaling, and rotation operations.

[0070] Step 7: Divide the material distribution map into multiple small areas. For the tire material distribution map, according to the selected MMP curve, 2k Points and MSP 2k+2 Find the perpendicular line of MMP line, denoted as N 2k and N 2k+2 , where k = 0 ~ n / 2-1, extract the material distribution map located at N 2k and N 2k+2 The line segment or figure between them is denoted as P k, outside N0, and N n The two regions outside the -1 and P n+1 , n is the number of equal parts in the fifth step.

[0071] Step 8: Each of the small areas P m (m=-1~n+1) performs affine transformation. m Perform affine transformation. For P m The coordinates of the graphics contained in , using their corresponding affine transformation parameters a m , b m , c m , d m , p m , q m , the coordinates of the transformed point are obtained according to the following formula:

[0072] (2)

[0073] Calculate P -1 Point-time utilization coefficient within the region a 0 , b 0 , c 0 , d 0 , p 0 , q 0 Perform calculations using a n , b n , c n , d n , p n , q n P n+1 The points in the area are transformed. The original material distribution diagram line composition remains unchanged, and the coordinates of the points are updated to the coordinates after affine transformation. At this point, the material distribution diagram of the actual tire is obtained.

[0074] Taking the 24570R17 tire as an example, in order to more intuitively illustrate the technical route of this patent, this embodiment only transforms the inner and outer contours:

[0075] Step 1: Inflate the tire to a standard pressure of 0.25 MPa, then deflate the tire until the internal pressure is 0.05 MPa. Use a laser scanner to scan the outer contour of the tire, recorded as O_S_P, as shown in the figure. Figure 1 As shown;

[0076] Step 2: According to the actual cross-section conditions (such as Figure 2 ), the tire profile is drawn (to represent the tire material distribution map), recorded as O_M_P, such as Figure 3 As shown, this material distribution diagram is a material distribution diagram of a cut tire cross section, which is in a relaxed state and is quite different from the actual tire profile;

[0077] Step 3: Smooth the outer contour of the tire. Since the actual outer contour of the tire contains elements such as grooves, decorative lines, fonts, etc., which leads to unevenness in the O_S_P line, it is necessary to manually process it into a smooth curve (such as Figure 4 As shown in the figure), the concave part of the groove is sealed with a smooth arc (as shown in the figure). Figure 5 As shown in the figure), the roughness caused by decorative lines and fonts is smoothed by arcs (as shown in the figure). Figure 6 ), the final smoothed curve is recorded as S_S_P, such as Figure 7 ;

[0078] Step 4: Smooth the outer contour curve of the tire material distribution map. The actual tire material distribution map also has uneven curves caused by grooves, decorative lines, and font lines. Similarly, the material distribution map needs to be smoothed in the same way as in step 4. The final smoothed curve is recorded as S_M_P, as shown in the following example: Figure 8 As shown;

[0079] Step 5: Select the curve set to be mapped. Select some continuous curves on the S_S_P contour as the target curve for mapping, such as Figure 9 , and divide it into equal parts. The principle of equal division is that the length of each part is no more than 0.5mm. The number of equal divisions is n=80. The target curve after equal division is recorded as M_S_P. Select some continuous curves on S_M_P as the original curve for mapping, such as Figure 10 As shown, it is also divided into equal parts, and the number of equal parts is also n=80. The target curve after equal division is recorded as M_M_P;

[0080] Step 6: Extract the node coordinates on M_S_P in counterclockwise order, recorded as MSP j , where j = 0 ~ 80. Similarly, extract the node coordinates on M_M_P in counterclockwise order, denoted as MMP i , where i = 0~80, take out the nodes in turn (MSP 2k , MSP 2k+1 , MSP2k+2 ) coordinates, and nodes (MMP 2k , MMP 2k+1 , MMP 2k+2 ) coordinates, where k = (0, 39), according to (MSP 2k , MSP 2k+1 , MSP 2k+2 ) and (MMP 2k , MMP 2k+1 , MMP 2k+2 ) The coordinates of the six nodes are calculated according to the following formula to calculate the affine transformation matrix:

[0081] (1)

[0082] in x * k , y* k represents the coordinates of the points on the M_S_P curve, x k and y k represents the coordinates of the points on the M_M_P curve, a k , b k , c k , d k , p k , q k are coefficients, which include translation, scaling and rotation operations. The calculation results are as follows Figure 11 .

[0083] Step 7: Divide the material distribution map into multiple small areas. For the tire material distribution map, according to the selected MMP curve, 2k Points and MSP 2k+2 Find the perpendicular line of MMP line, denoted as N 2k and N 2k+2 , where k = 0 ~ 39, extract the material distribution map located in N 2k and N 2k+2 The line segment or figure between them is denoted as P k , outside N0, and N n The two regions outside the -1 and P n+1 , n is the number of equal parts in step 6, 80, such as Figure 12 shown.

[0084] Step 8: Each of the small areas Pm (m=-1~40) performs affine transformation. m Perform affine transformation. For P m The coordinates of the graphics contained in , using their corresponding affine transformation parameters a m , b m , c m , d m , p m , q m , the coordinates of the transformed point are obtained according to the following formula:

[0085] (2)

[0086] Calculate P -1 Point-time utilization coefficient within the region a 0 , b 0 , c 0 , d 0 , p 0 , q 0 Perform calculations using a n , b n , c n , d n , p n , q n P n+1 The points in the area are transformed. The original material distribution diagram line composition remains unchanged, and the coordinates of its points are updated to the coordinates after affine transformation. At this point, the material distribution diagram of the actual tire is obtained, as shown in Figure 13 .

[0087] Through the above steps, the real material distribution map of the tire is obtained, and the simulation analysis and actual measurement are compared using the mold contour. Figure 14 As shown in the figure, the simulation analysis using the transformed material distribution map (real material distribution map) is compared with the actual measurement. Figure 15 As shown, Figure 14 The simulation results show a big difference from the measured results. Figure 15It shows that the simulation results are very close to the calculated results, so that the subsequent simulation analysis results can be accurate, which proves the effectiveness of this method.

[0088] The above is a description of the embodiments of the present invention. The above description of the disclosed embodiments will enable professionals in the field to implement or use the present invention. Various modifications to these embodiments will be apparent to professionals in the field. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for obtaining an actual material distribution map for tire performance analysis, characterized in that: The following steps are involved: Step 1: Inflate the tire to the standard pressure, then deflate it until the internal pressure is 0.05 MPa. Use a laser scanner to scan the outer contour of the tire, denoted as O_S_P, to obtain a dxf file containing the outer contour of the tire. Step 2: Import the image into CAD software and draw the material distribution map of the tire according to the actual cross-section, which is recorded as O_M_P; Step 3: Smooth the outer contour of the tire The concave part of the groove is sealed with a smooth arc, and the unevenness caused by the decorative lines and fonts is smoothed with an arc. The final smoothed curve is recorded as S_S_P. Step 4: Smooth the outer contour curve of the tire material distribution map The actual tire material distribution map also has uneven curves caused by tread grooves, decorative lines, and font lines. Similarly, the material distribution map needs to be smoothed in the same way as in step 3. The final smoothed curve is recorded as S_M_P. Step 5: Select the curve set that needs to be mapped; Select a continuous curve on the S_S_P contour as the target curve for mapping and divide it into equal parts. The principle of equal division is that the length of each part is no longer than 0.5 mm. The number of equal divisions is n, where n>30 and n is an even number. The target curve after equal division is recorded as M_S_P. Select a continuous curve on the S_M_P contour as the original curve for mapping and divide it into equal parts. The number of equal divisions is also n. The target curve after equal division is recorded as M_M_P. Step 6: Extract the node coordinates on M_S_P in counterclockwise order, recorded as MSP j , where j = 0~n; similarly, extract the node coordinates on M_M_P in counterclockwise order, denoted as MMP i , where i=0~n, take out the node MSP in turn 2k , MSP 2k+1 , MSP 2k+2 The coordinates of the node MMP 2k , MMP 2k+1 , MMP 2k+2 The coordinates of, where k = (0, n / 2-1), according to MSP 2k , MSP 2k+1 , MSP 2k+2 and MMP 2k , MMP 2k+1 , MMP 2k+2 The coordinates of the six nodes are used to calculate the affine transformation matrix according to the following formula: (1) in x * k , y* k represents the coordinates of the points on the M_S_P curve, x k and y k represents the coordinates of the points on the M_M_P curve, a k , b k , c k , d k , p k , q k is the coefficient; Step 7: Divide the material distribution map into multiple small areas For the tire material distribution diagram, according to the selected MMP curve, the MSP 2k Points and MSP 2k+2 Find the perpendicular line of MMP line, denoted as N 2k and N 2k+2 , where k = 0 ~ n / 2-1, extract the material distribution map located at N 2k and N 2k+2 The line segment or figure between them is denoted as P k , outside N0, and N n The two regions outside the -1 and P n+1 , n is the number of equal parts in step 5; Step 8: Each of the small areas P m Perform affine transformation, m=-1~n+1; respectively divide the small area P m Perform affine transformation; for P m The coordinates of the graphics contained in , using their corresponding affine transformation parameters a m , b m , c m , d m , p m , q m , the coordinates of the transformed point are obtained according to the following formula: (2) Calculate P -1 Point-time utilization coefficient within the region a 0 , b 0 , c 0 , d 0 , p 0 , q 0 Perform calculations using a n , b n , c n , d n , p n , q n P n+1 The points in the area are transformed, keeping the linear composition of the original material distribution map unchanged, and the coordinates of the points are updated to the coordinates after affine transformation. At this point, the material distribution map of the actual tire is obtained.

2. A system for obtaining a tire's actual material distribution map, characterized in that: The system implements the method according to claim 1, comprising: Laser scanning module: used to scan the outer contour of the tire and generate a vector file containing the outer contour data; Drawing module: used to import actual cross-section images and draw tire material distribution maps; Smoothing module: smoothing the tire outer contour and material distribution map; Segmentation module: used to segment the material distribution map into multiple small areas according to the mapping curve; Affine transformation module: used to calculate the affine transformation matrix and perform affine transformation operations on small areas; Output module: Outputs the updated actual material distribution map.

3. The system according to claim 2, wherein: The affine transformation module includes: The node extraction submodule is used to extract the coordinates of equally divided nodes of the mapping curve; Matrix calculation submodule, used to calculate the affine transformation matrix based on the node coordinates; The coordinate transformation submodule is used to perform coordinate affine transformation of a small area.

4. The system according to claim 2, wherein: The output module can export the updated material distribution map into multiple formats, including dxf, svg or other compatible formats, to facilitate subsequent simulation analysis.

5. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instruction is executed by a processor, the method according to claim 1 is implemented.

6. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the method according to claim 1 is implemented.

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