A tire pattern performance simulation precision improvement method and system, a storage medium and a software product

Abstract

This invention relates to the field of tire simulation design technology, and more particularly to a method, system, storage medium, and software product for improving the accuracy of tire tread performance simulation. The invention constructs a pressure mesh by reading measured data from a pressure sensor array, sets a pressure threshold to extract contour nodes, and connects and traces them to form a closed contour. The outer contour of the ground contact mark is obtained by combining area threshold filtering and convex hull calculation. Further, the ground contact width (TAW) of the tread pattern unfolded diagram is read, the maximum width of the outer contour (B) is calculated, and the scaling factor k = TAW / B is obtained. The outer contour is mapped to the unfolded diagram to obtain a mapped contour, which is used to limit the extraction of tread parameters within the ground contact area and input into noise, handling, and / or wear simulation modules. This solution achieves end-to-end automation, reduces manual drawing errors and time, and improves geometric input consistency and simulation prediction accuracy.

Description

Technical Field

[0001] This invention relates to the field of tire simulation design technology, and in particular to a method, system, storage medium, and software product for improving the accuracy of tire tread performance simulation. Background Technology

[0002] The development of tire tread performance typically relies on a combined process of experimental verification and numerical simulation / semi-empirical prediction. Among these, performance characteristics such as noise, handling, and wear are extremely sensitive to the geometry and load distribution of the tire within the contact patch area. The contact patch not only determines the effective contact area between the tread blocks and the road surface but also directly affects key physical quantities such as boundary excitation of the tread blocks, the effectiveness of groove drainage channels, contact stiffness distribution, local slippage, and shear energy dissipation. This, in turn, has a decisive impact on tread noise radiation, handling stability, and wear trends. In practical engineering, tread simulation often requires extracting tread parameters (such as the total side length of tread blocks within the contact area, the proportion of pitch / pitch boundary involved in contact, local tread block perimeter, and edge density) from the tread unfolded diagram (two-dimensional unfolded, ideally without deformation) or three-dimensional tread model, and then inputting these parameters into the noise / handling / wear simulation module or evaluation model. Because tires undergo significant structural deformation under factors such as load, air pressure, speed, and temperature, there are often differences in scale and shape between the measured ground contact imprint outline and the geometric outer boundary of the two-dimensional tread pattern unfolded diagram: the unfolded diagram's outline is idealized and larger in size, while the measured imprint better reflects the actual ground contact range. If a stable and reproducible geometric mapping relationship cannot be established between the measured imprint outline and the unfolded diagram, two typical problems will arise: First, the inconsistency between the simulation input boundary and the actual ground contact boundary leads to statistical deviations in tread pattern parameters, resulting in errors in noise / handling / wear prediction; second, the traditional method of manually drawing or selecting points to fit the imprint boundary is inefficient, has poor repeatability, and the subjective differences between different operators introduce additional uncertainties. Therefore, how to automatically and robustly extract the measured ground contact imprint outline from engineering-available data formats (such as pressure matrix / tabular files output by pressure sensor arrays) and geometrically align and map this outline to the tread pattern unfolded diagram is a crucial technical challenge for improving the accuracy of tread pattern performance simulation and R&D efficiency.

[0003] In existing technologies, multiple technical routes have been developed around the acquisition of grounding imprints, contour determination, and grounding parameter extraction. However, these routes still have shortcomings compared to the automatic contour extraction based on measured pressure data, the mapping and matching with tread pattern development diagrams, and the incomplete matching of inputs for tread performance simulation described in this invention. For example, Chinese patent CN116579085A provides a method, application, and program product for extracting the contour of grounding imprints from tires with tread grooves. Its approach starts from the node coordinates and grounding pressure information after the tire model is deformed, refines and interpolates the grounding pressure, extracts minimum pressure contour lines, and obtains the imprint contour through geometric processing such as point set triangulation and identification of convex edges. It emphasizes the advantages of speed, standardization, and customizable minimum pressure threshold in simulation imprint contour extraction. The value of this type of solution lies in its ability to reliably extract imprint boundaries from simulation results using contour lines and geometric operations, and its suitability for integration with finite element simulation processes. However, its data sources and engineering application goals are mostly biased towards the node / pressure field output by the simulation model, rather than the tabular pressure data derived directly from the actual pressure sensor array. At the same time, its focus is on obtaining the simulated imprint contour, and it does not provide a specific mapping strategy and reproducible matching process for the geometric differences between the two-dimensional pattern unfolding diagram and the measured imprint outer contour. Therefore, when using the measured outer contour as the statistical boundary of the pattern unfolding diagram's internal parameters, it may still face deviations and engineering implementation difficulties caused by inconsistent input coordinate systems and scales.

[0004] Chinese patent CN110567394A proposes a method for determining the tire-road contact envelope contour based on the imprint method. This method determines the envelope contour and calculates the contact area through imprint-based contact. It also proposes using the cubic difference method for interpolation to mitigate unnecessary oscillations that may be introduced by cubic spline interpolation, thus making the envelope contour more consistent with the actual contact envelope. Furthermore, it establishes a correlation analysis between the obtained envelope contour and road surface texture feature parameters (such as MPD). This type of scheme focuses on the construction of the tire-road contact envelope and the improvement of the stability of the interpolation algorithm, providing a valuable reference for the numerical reliability of envelope contour calculation. However, its focus is mainly on macroscopic analysis links such as contact envelope / texture parameters / rolling resistance correlation, and it usually does not directly address the statistical analysis of pattern geometric parameters and the correction of input boundaries for noise / manipulation / wear simulation within the pattern unfolding diagram. At the same time, in engineering implementation, it often emphasizes the solution and interpolation strategy of the envelope contour itself, and may not provide robust processing steps such as automatic extraction of the entire link from the measured pressure matrix of the pressure sensor array to the closed polygon outer contour point set, filtering of small closed regions, and convex hulling of the outer contour. Furthermore, it does not provide a mapping and scaling mechanism for key dimensions such as the ground width of the unfolding diagram. Therefore, there is still a gap in solving the problem of geometric deviation caused by directly using the measured outer contour as simulation input for the unfolding diagram.

[0005] Chinese patent CN109447959A provides a method for measuring tire static load imprints. It acquires ground imprint images under different loads using a laser and camera (dark-field imaging), performs Gamma transformation and binarization preprocessing, selects marker points at the imprint boundary, and chooses the curve fitting order or spline interpolation method based on the imprint morphology to finally obtain the tire ground imprint boundary curve. This method emphasizes detection accuracy and speed, as well as adaptability to tires with different tread patterns. The advantage of this approach is that the imprint morphology can be intuitively obtained through visual / optical methods, and the boundary curve can be formed through fitting or spline interpolation. However, from an engineering perspective, the boundary generation process may still rely on manual intervention, such as selecting marker points at the boundary, and automation and consistency are easily affected by the operator. Furthermore, the image measurement yields the boundary curve in image coordinates or measurement platform coordinates, which still presents differences in scale, alignment reference, and unfolding deformation compared to the tread pattern coordinate system. For scenarios where the boundary needs to be further used for statistical analysis of pattern parameters within the unfolded diagram and for noise / manipulation / wear simulation input, if there is a lack of mapping rules for engineering dimensions such as the ground width of the unfolded diagram and a reproducible scaling / registration process, errors may still accumulate even if the boundary is correct but the input geometry is mismatched.

[0006] In addition, some technologies focus on extracting grounding parameters from grounding pressure distribution and establishing a correlation with performance. For example, Chinese patent CN108801659B extracts grounding parameters from grounding pressure distribution images and establishes the relationship between grounding parameters and hydroplaning and noise performance based on correlation analysis and principal component analysis for parameter screening and characterization. These approaches embody the grounding parameter-performance modeling concept, but their core is not the automatic extraction of the measured imprint outline, geometric mapping and matching with the pattern unfolding diagram, or the end-to-end problem of correcting simulation boundary inputs. Therefore, they cannot directly solve the pain point of simulation deviation caused by the inconsistency between the two-dimensional unfolded geometry and the measured grounding boundary, which is the focus of this invention.

[0007] In summary, existing technologies for imprint contour extraction cover multiple aspects, including simulated imprint geometry extraction, imprint envelope and interpolation correction, optical measurement and boundary fitting, and correlation between grounding parameters and performance. However, they still generally suffer from the following shortcomings: 1) Many solutions do not use the tabulated pressure matrix measured by the pressure sensor array as the data input, or do not provide a robust automated process from this type of data to a closed outer contour point set; 2) Even if the measured imprint boundary is obtained, there is often a lack of an engineering mapping and matching mechanism between it and the pattern unfolding diagram, especially a lack of scaling factor calculation and coordinate update rules based on the size constraints such as the ground width of the unfolding diagram. This makes it difficult for the measured boundary to be directly used as an effective boundary for the statistical analysis and simulation of pattern parameters within the unfolding diagram; 3) For problems such as noise, small internal closed regions, and local fractures in the measured pressure data, existing solutions may not systematically provide a robust processing chain combining closed contour tracking, internal region removal, area threshold filtering, and outer contour convex hull transformation, thus affecting boundary stability and repeatability.

[0008] Therefore, there is still an urgent need for a technical solution that is oriented towards the form of engineering measured data and can realize full-link automation: it can automatically extract a stable set of outer contour points from the measured ground pressure matrix and establish a geometric mapping relationship between the outer contour and the pattern unfolding diagram, so that the mapped measured boundary can directly constrain the extraction of pattern parameters and the input of noise / manipulation / wear simulation in the unfolding diagram, thereby improving the prediction accuracy and significantly reducing manual labor time. Summary of the Invention

[0009] The technical objective of this invention is to address the problems in existing tire tread performance simulations, such as the reliance on manual drawing of the measured ground contact mark outer contour, which is inefficient and inconsistent, and the discrepancies in scale and geometry between the measured mark and the tread pattern development diagram leading to mismatch in simulation input boundaries and increased prediction deviations. This invention provides a method and program that can automatically extract the closed outer contour from measured ground pressure data and establish a reproducible geometric mapping relationship with the tread pattern development diagram. This allows the mapped real ground contact boundary to be directly used as simulation input and parameter extraction for tread performance parameters such as noise, handling, and / or wear, thereby improving simulation accuracy and shortening the development cycle.

[0010] Firstly, in order to achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0011] A method for improving the simulation accuracy of pattern performance based on automatic extraction and mapping of the outer contour of measured grounding imprints, the method includes the following steps:

[0012] S1, Collect measured tire ground pressure data and read it as a two-dimensional pressure array. ;

[0013] S2, with pressure sensor array spacing Will Construct a ground pressure grid and set a pressure threshold. When the coordinates of the two endpoints of any grid edge , Corresponding pressure satisfy or At that time, contour line nodes are determined between the two endpoints, and the coordinates of the threshold nodes are obtained using cubic spline interpolation. Then, perform connectivity tracing on all threshold nodes to form at least one closed contour; filter the closed contour to remove small closed regions and areas smaller than the area threshold. The closed region is defined, and the convex hull is calculated for the preserved contour point set to obtain the measured outer contour of the grounding imprint. ;

[0014] S3, Read the ground width of the pattern unfolding diagram And calculate the outer contour Maximum width Calculate the scaling factor: ; and the outer contour Horizontal coordinates of each point Updated to: ; Obtain the outer contour of the mapped grounding imprint ;

[0015] S4, outer contour Register with the coordinate system of the pattern development diagram to determine The set of pattern geometric parameters within the defined grounding area ;

[0016] S5, with Simulations or predictions of pattern noise, handling, and / or wear performance are performed using geometry as input to output performance metrics. .

[0017] Preferably, the measured grounding pressure data in step S1 is collected by a pressure sensor array and stored in a table file, where each cell in the table file corresponds to the pressure value of a pressure grid node; the table file is then parsed into a two-dimensional pressure array. Imputation is performed on the missing values; wherein the table file is an Excel file or an equivalent expression; the imputation is bilinear imputation or imputation based on the neighborhood mean; the neighborhood is centered on the missing point. window, It is an odd number that is not less than 3.

[0018] Preferably, the grid side length of the pressure grid in step S2 is equal to the array spacing. And the pressure value of each grid node is composed of a two-dimensional pressure array. The array elements are given; where, The center distance between adjacent pressure sensor measuring points;

[0019] And / or, in step S2, when the pressure at both ends of the mesh edge... Pressure threshold at different locations When both sides, by the pressure field Interpolation along the grid edge yields the result that satisfies... Threshold node coordinates ;in, For a two-dimensional pressure array Defined pressure field query function; The coordinates of the outline nodes;

[0020] And / or, the cubic spline interpolation in step S2 includes: using the node index as a parameter Parameterize the candidate node sequence and construct respectively and Find the cubic spline function and find the function that satisfies... parameters To obtain the threshold node coordinates ;in, For parameter index; , It is a spline interpolation function;

[0021] And / or, the connectivity tracing in step S2 adopts a 4-connectivity or 8-connectivity rule, starting from any threshold node and connecting the threshold nodes sequentially according to their adjacent relationships until returning to the starting point, forming a closed contour path; wherein, 4-connectivity connects only the adjacent nodes in the top, bottom, left and right; 8-connectivity connects the adjacent nodes in the top, bottom, left and right and diagonally.

[0022] And / or, the filtering in step S2 includes: calculating the area of ​​each closed contour. and delete area Closed contours and closed contours located inside the outer contour, only retain those that satisfy... The set of points representing the outer closed contour is used for subsequent convex hull calculation; where, The area of ​​the closed contour; This is the minimum retention area threshold.

[0023] Preferably, the convex hull calculation in step S2 uses the Graham scan algorithm, the Andrew monotonic chain algorithm, or the equivalent convex hull algorithm, with the output being the smallest convex polygon containing the set of points that preserve the contour as the outer contour. ;in, It is a closed polygon formed by connecting the vertices of the convex hull in sequence.

[0024] Preferably, the maximum width mentioned in step S3 Determine by the following formula:

[0025] ;

[0026] in, Outer contour The horizontal coordinates of each point in the middle; and Use the same unit of length.

[0027] And / or, the mapping described in step S3 applies only to the horizontal coordinate. Scaling is performed to compensate for the difference in lateral dimensions between the pattern unfolded diagram and the measured grounding imprint, and the resulting mapped outer contour is obtained after scaling. Keep the vertical coordinate of the point Unchanged. Among them, Here are the longitudinal coordinates of the outer contour points.

[0028] Preferably, the registration in step S4 includes: using the center line or boundary line of the pattern unfolding diagram as a reference, mapping the outer contour. Perform translation and rotation angle Correction is performed to ensure that the registration error is no greater than the threshold. ;in, This is the translation amount; The rotation angle; The registration error is the average point-to-boundary distance or the Hausdorff distance.

[0029] And / or, the set of pattern geometric parameters described in step S4 At least the number of patterned blocks Total side length , interval sequence and the set of patterned blocks perimeter .in, Count the patterned blocks; ; It is an ordered arrangement of pitches; For the first The perimeter of each patterned block.

[0030] Preferably, the performance indicators described in step S5 At least including: noise indicators Control indicators and wear index One or more of these, and output by the corresponding simulation model. This is the predicted noise value; To manipulate the predicted values; This is the predicted wear value.

[0031] Secondly, the present invention also provides a tire contact patch contour extraction and comparison / mapping system. This system is used to implement the method described above, including a data reading module, a contour extraction module, a contour mapping module, and a performance simulation module. The data reading module is used to execute step S1; the contour extraction module is used to execute step S2; the contour mapping module is used to execute steps S3 and S4; and the performance simulation module is used to execute step S5 and output performance indicators. .

[0032] Thirdly, the present invention also provides a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the steps of the method.

[0033] Fourthly, the present invention also provides a computer program product, including a computer program or instructions that, when executed by a processor, implement the steps of the method.

[0034] This invention, by employing the aforementioned technical solution, achieves a transformation of grounding boundary control from manual intervention to automation, standardization, and reproducibility: on the one hand, it utilizes a pressure threshold... Contour points are determined by isoline node identification and obtained through cubic spline interpolation. Closed paths are then formed through connected tracing. By filtering out small, enclosed areas and extracting the convex hull to obtain a unique outer contour, boundary extraction becomes more robust to measured noise points, local breaks, and multi-region imprints, significantly reducing contour differences caused by different operators and different batches. On the other hand, the unfolded diagram is used to determine the ground width. The maximum width of the measured outer contour Calculate scaling factor Furthermore, a consistent mapping was performed on the lateral coordinates of the outer contour, resolving the geometric inconsistency between the ideal, undistorted 2D pattern unfolded diagram, the oversized outer contour, and the actual grounding range of the measured imprint. This ensured that the mapped contour... It can serve as a true boundary constraint for geometric inputs such as the perimeter, total side length, and pitch of the patterned blocks in the unfolded diagram, thus reducing geometric input errors from the source and minimizing noise, handling, and wear prediction deviations caused by boundary mismatches. In terms of engineering benefits, this invention can replace the time-consuming process of traditional manual screenshot drawing with a programmed processing flow, significantly reducing manual time and increasing processing throughput. At the same time, it stabilizes the outer contour extraction accuracy at the millimeter level, and the geometric input error after mapping can be controlled within 1%. This improves the consistency and accuracy of performance simulations such as pattern noise, handling, and wear, shortens the R&D iteration cycle, and improves the selection efficiency and reliability of pattern design schemes. Attached Figure Description

[0035] Figure 1This is a schematic diagram of pattern block outline extraction and block positioning in the pattern unfolding diagram. The black lines represent the boundaries of the pattern blocks, and the red frames represent the positioning boxes or block recognition boxes generated based on the outer regions of the pattern blocks.

[0036] Figure 2 This is a schematic diagram of the outlined result of the pattern unfolding diagram, showing the boundary lines of the pattern blocks and the groove boundary lines obtained by image outline or vector boundary extraction.

[0037] Figure 3 The outer contour line of the grounding imprint is automatically extracted from measured grounding pressure data. A schematic diagram.

[0038] Figure 4 The ground width of the pattern unfolding diagram Schematic diagram of the measurement.

[0039] Figure 5 This is a schematic diagram showing the superimposed overlay of the measured grounding imprint outline onto the pattern unfolded diagram.

[0040] Figure 6 This is a block diagram of the tire ground contact mark contour extraction and mapping system of the present invention.

[0041] Figure 7 This is a flowchart of the method of the present invention. Detailed Implementation

[0042] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be understood that the following embodiments are used to illustrate the technical solutions of the present invention, and not to limit the scope of protection of the present invention. Equivalent substitutions made by those skilled in the art for data formats, interpolation algorithms, connected pursuit methods, outer envelope generation methods, pattern parameter statistical methods, or performance simulation interfaces without departing from the technical concept of the present invention should all be included within the scope of protection of the present invention.

[0043] I. Terminology Explanation

[0044] The measured ground pressure data described in this invention refers to the pressure distribution data of the tire ground contact area collected by a pressure sensor array, typically saved in the form of an Excel spreadsheet, CSV file, or other equivalent two-dimensional matrix file. Each data unit corresponds to the pressure value of a measuring point in the pressure sensor array.

[0045] The two-dimensional pressure array described in this invention It refers to a two-dimensional matrix obtained by analyzing measured ground pressure data, where the elements in the matrix... Indicates the first Line 1 The pressure values ​​at the measuring points should preferably be uniformly expressed in Pa.

[0046] The array spacing described in this invention This refers to the center-to-center distance between adjacent measuring points in a pressure sensor array, measured in mm. Array spacing. Used to convert two-dimensional pressure array Mapped to a regular pressure grid.

[0047] The pressure threshold described in this invention This refers to the equivalent pressure threshold used to determine the boundary of a grounding zone. When the pressure at adjacent measuring points is... When the threshold is on both sides, it indicates that there is a grounding boundary threshold node between the adjacent measuring points. Pressure threshold The sensitivity can be set according to the sensor noise level, test load, tire specifications, and ground boundary identification.

[0048] The threshold node described in this invention refers to a node whose pressure value is equal to the threshold node obtained by interpolation calculation on adjacent grid edges. The point is denoted as Multiple threshold nodes are connected according to their adjacency relationship to form the equivalent boundary of the grounding imprint.

[0049] The closed profile described in this invention refers to a closed path formed by sequentially connecting multiple threshold nodes according to their mesh adjacency relationship. Due to the influence of pattern grooves, local pressure noise, or discontinuous pressure distribution, the closed profile may include the main grounding area profile, the internal closed area profile, and the small-area noise profile.

[0050] The area threshold described in this invention This refers to the minimum area threshold used for filtering small, enclosed regions. Areas smaller than... The closed contour is judged as a noise region, an isolated contact point region, or a non-primary grounding region, and does not participate in the generation of the outer contour.

[0051] The outer contour described in this invention , refers to the outer boundary of the ground imprint obtained after performing outer envelope calculation on the set of points that retain the closed contour. It is preferably a convex hull boundary, but can also be an α-shaped boundary that can retain the continuity of the outer boundary or the outer boundary after morphological closing operation. Figure 3 The outer contour is shown. One form.

[0052] The tread pattern development diagram described in this invention refers to a two-dimensional graphic formed by unfolding the tire tread pattern circumferentially, which includes information such as the tread block boundaries, groove boundaries, pitch boundaries, and tread lateral boundaries. Figure 1 and Figure 2 The block positioning results and contouring results of the pattern unfolding diagram are shown respectively.

[0053] The ground width of the unfolded diagram described in this invention This refers to the horizontal width used in the geometric statistics of the grounding area in the pattern development diagram, such as... Figure 4 As shown. It serves as a metric for mapping the measured outer contour of the grounding imprint onto the pattern unfolding diagram.

[0054] The maximum width described in this invention It refers to the measured outer contour of the grounding imprint. The maximum span in the horizontal direction.

[0055] The scaling factor described in this invention This refers to the measured outer contour. The horizontal scaling factor used when mapping to the pattern unfolding scale.

[0056] The mapped outer contour of the present invention This refers to the measured outer contour. By scaling factor The contour obtained after updating the lateral coordinates, such as Figure 5 As shown. Mapped outer contour Being on the same geometric scale as the pattern unfolding diagram, it can be directly used to define the actual grounding area in the unfolding diagram.

[0057] The pattern geometric parameter set described in this invention This refers to mapping the outer contour. The geometric parameters of the pattern extracted within the defined grounding area include at least the number of pattern blocks. , collection of patterned block perimeters Total side length , interval sequence One or more of the following: trench area ratio and edge density within the grounding area.

[0058] The performance indicators described in this invention This refers to the simulation or prediction results of noise, handling, and / or wear, which may include noise indicators. Control indicators and wear index .

[0059] II. System Structure

[0060] like Figure 6 As shown, this invention provides a tire contact patch contour extraction and mapping system. This system can be deployed on a tire tread simulation workstation, server, or ordinary computer, and can also run as a plug-in or script program to existing tread simulation software, finite element simulation software, or performance prediction programs. The system includes at least a data reading module, a contour extraction module, a contour filtering and outer contour generation module, a contour mapping module, a registration and contact patch area determination module, a tread parameter extraction module, and a performance simulation / prediction interface module.

[0061] The data reading module is used to read the measured ground pressure data file exported by the pressure sensor array and parse it into a two-dimensional pressure array. This module can also read the array spacing. Information such as pressure unit, sampling time, test load, tire pressure, tire specifications, and document number is included. If there are missing values, bad points, or outliers in the measured data, the data reading module can perform preprocessing using neighborhood mean interpolation, bilinear interpolation, or median filtering to ensure the continuity and stability of subsequent contour boundary extraction.

[0062] The contour extraction module is used for two-dimensional pressure arrays. Establish a pressure grid and base it on a pressure threshold. Determine if any grid edge crosses a threshold. When the pressure at both ends of any grid edge... , satisfy or At that time, the contour extraction module calculates the threshold node on the edge of the grid. And all threshold nodes are connected and traced according to their adjacency relationships to form a closed contour set.

[0063] The contour filtering and outer contour generation module is used to calculate the area of ​​closed contour sets, remove internal contours, and filter small regions. Then, it performs outer envelope calculation on the retained contour point set to generate the measured outer contour of the grounding imprint. This module corresponds to Figure 3 The generated outer contour shown is an important component that distinguishes this invention from manual drawing methods.

[0064] The contour mapping module is used to read the ground width of the pattern unfolding diagram. And calculate the measured outer contour. Maximum width Then according to and Calculate scaling factor Outer contour Update the horizontal coordinates to obtain the mapped outer contour. This module aims to resolve the scale discrepancy between the measured grounding imprint and the pattern unfolded diagram.

[0065] The registration and grounding region determination module is used to map the outer contour. Place it in the coordinate system of the pattern unfolding diagram, and perform translation, rotation, or center alignment according to the center line, boundary line, or specified reference point of the unfolding diagram to map the outer contour. It can stably define the actual grounding area in the unfolded diagram. Figure 5 The mapped outer contour is shown. The effect after overlaying the pattern unfolded diagram.

[0066] The pattern parameter extraction module is used to map the outer contour. Within the defined area, parameters such as the number of patterned blocks, the perimeter of the patterned blocks, the total side length, the pitch sequence, the edge density, and the groove area ratio are extracted. Figure 1 and Figure 2 Based on the results of pattern block boundary recognition and contouring, this module can... Figure 1 The external positioning frame quickly determines whether the patterned block is located within the grounding area, and based on... Figure 2 The geometric parameters of the patterned block contour are calculated.

[0067] The performance simulation / prediction interface module is used to set the pattern geometry parameters. Input to noise, handling, and / or wear simulation models, output performance indicators This module can connect to finite element simulation, acoustic simulation, wear prediction models, as well as existing semi-empirical performance evaluation programs used by enterprises.

[0068] The technical advantage of the above system structure is that it transforms the traditional discrete process of "manually reading the measured imprint - manually drawing the outer contour - manually overlaying the pattern - manually calculating the parameters" into a continuous processing link of "measured pressure data - automatic contour extraction - automatic mapping - automatic parameter statistics - simulation interface output", so that the measured grounding boundary can be stably entered into the pattern performance simulation input system.

[0069] III. Specific Technical Route for Implementing the Method of the Invention

[0070] like Figure 7 As shown, the method of the present invention includes steps S1 to S5. The specific implementation of each step is described below.

[0071] Step S1: Obtain measured grounding pressure data and construct a two-dimensional pressure array.

[0072] In step S1, the tire to be tested is first mounted on the pressure sensor array test platform, and the ground pressure is measured under the set inflation pressure, load, and ambient temperature conditions. The pressure sensor array outputs a two-dimensional pressure matrix file. After reading this file, the pressure values ​​at each measuring point are converted into a two-dimensional pressure array. .

[0073] If the original pressure unit is not Pa, unit conversion will be performed during reading. If null values, bad pixels, or obvious outliers exist, neighborhood mean interpolation or bilinear interpolation can be used. For missing points... You can take the surrounding area. The mean of the effective pressure values ​​in the neighborhood is used as the interpolation value, where It is an odd number not less than 3. After preprocessing, a two-dimensional pressure array is output. and array spacing .

[0074] In one implementation, to avoid boundary spikes caused by a single outlier, the two-dimensional pressure array can be... Perform light median filtering. For example, use a 3×3 neighborhood window to filter the pressure field, but the filter strength should not be too large to avoid changing the edge position of the grounding imprint. The filtered array is still denoted as... .

[0075] The purpose of this step is to provide a unified data foundation for subsequent contour extraction. Since pressure sensor array data usually already has a fixed row and column relationship, this step mainly involves data reading and standardization, and its contribution to the overall creativity is relatively low. However, it ensures the feasibility and repeatability of subsequent threshold node calculations.

[0076] Step S2: Automatically extract the outer contour of the grounding imprint based on the measured pressure grid.

[0077] Step S2 is a crucial technical step in this invention, contributing significantly to its inventiveness. Traditional methods typically rely on manual screenshotting, manual outlining, or manual selection of boundary points, which is not only time-consuming but also results in inconsistencies in contour outcomes between different operators. This invention transforms the manual outlining process into a repeatable, procedural workflow through pressure threshold contour node extraction, closed contour tracking, area filtering, and outer envelope calculation, thereby improving the efficiency and stability of contour extraction.

[0078] 2.1 Pressure Mesh Modeling

[0079] First, the system will use a two-dimensional pressure array. Mapped to a pressure grid. If the array index is... Its corresponding coordinates can be defined as:

[0080] ;

[0081] In the formula, For the first Line 1 List the lateral coordinates of the measurement points; For the first Line 1 The longitudinal coordinates of the measurement points; This represents the spacing between the pressure sensor arrays.

[0082] The coordinate definitions described above can also be translated or flipped axially according to the coordinate system of the test platform. For example, the center of the measured grounding imprint can be set as the origin, or the upper left corner of the test platform can be set as the origin. This is only necessary for the subsequent outer contour width. and horizontal coordinates The definition remains consistent, meaning it will not affect the scaling mapping result.

[0083] 2.2 Threshold Crossing Determination

[0084] The system performs threshold crossing determination on each grid edge of the pressure grid. For any adjacent grid points... and Its corresponding pressure value and When satisfied or When, this indicates pressure contour lines. Passing through the edge of the grid, meaning there is a ground imprint boundary node on the edge of the grid.

[0085] In actual engineering data, noise may exist in the edge region of the pressure sensor. Therefore, the minimum span can be further set. .when Less than Even if it crosses in form Alternatively, threshold nodes can be temporarily withheld to avoid generating a large number of pseudo-nodes in noisy regions. This minimum span... This parameter can be determined based on the sensor's noise floor. If the sensor output has already undergone stable filtering, this parameter can also be omitted.

[0086] 2.3 Threshold Node Coordinate Calculation

[0087] To calculate the coordinates of the threshold node, linear interpolation or cubic spline interpolation can be used. In one specific implementation, linear interpolation is first used to determine the initial threshold node position:

[0088] ;

[0089] In the formula, The interpolation scaling factor on the grid edge; Pressure threshold; , These are the pressure values ​​at both ends of the grid edge.

[0090] Further, the coordinates of the threshold node are obtained:

[0091] ;

[0092] In the formula, , The coordinates of the threshold node; , , , The coordinates of the two endpoints of the grid edge; This is the interpolation scaling factor.

[0093] In another implementation, to obtain a smoother boundary, cubic spline interpolation can be applied to the candidate boundary node sequence, using the node index as a parameter. , respectively construct and And solve for the following equation using the pressure field query function. :

[0094] ;

[0095] In the formula, For coordinates The pressure field query value at the location; Pressure threshold; For parameterized indexes; , These are the coordinate functions obtained by cubic spline interpolation.

[0096] In actual program implementation, linear interpolation can be used to obtain the initial contour nodes first, then cubic spline smoothing can be performed on the nodes of the same local contour segment, and the smoothed contour can be resampled. This can maintain the reliability of the boundary position and reduce the impact of jagged boundaries on subsequent convex hull or parametric statistics.

[0097] 2.4 Connectivity tracing forms closed contours

[0098] After calculating the threshold nodes, the system performs connectivity tracing on all threshold nodes based on grid adjacency relationships. Either 4-connectivity or 8-connectivity rules can be used. 4-connectivity connects only adjacent nodes in the vertical, horizontal, and vertical directions, while 8-connectivity further connects adjacent nodes in the diagonal directions. In tire ground pressure maps, the boundaries may have slight jagged edges or local breaks; using the 8-connectivity rule can improve the success rate of closed path tracing.

[0099] Starting from any unvisited threshold node, the system searches for the next contour node sequentially according to adjacency relationships. If multiple candidate nodes exist, the candidate node with the smallest angle to the previous direction can be selected to maintain the continuity of the contour. The system continues searching until the tracing path returns to the starting point, or the distance to the starting point is less than the closing distance threshold. At that time, a closed contour is determined. Repeat the above process until all threshold nodes have been visited, thus obtaining a set of closed contours. .

[0100] Closure distance threshold According to the array spacing Settings. For example, optional. for to The range. If the distance between the end and the start of a closed path is slightly large, but they belong to the same boundary segment, a closed path can also be formed by connecting the endpoints or filling in small gaps.

[0101] 2.5 Area Filtering and Internal Contour Removal

[0102] Because the measured pressure field may contain internal closed lines formed by patterned grooves, small closed areas formed by local pressure noise, and edge burrs, not all closed contours can be directly used as the outer contour of the grounding imprint. This invention further calculates and filters the area of ​​the closed contours.

[0103] For closed contours Its vertices are in order. ,area It can be calculated using the following formula:

[0104] ;

[0105] In the formula, For the first The area of ​​a closed contour; This represents the number of vertices of the closed contour. , For the first The coordinates of each vertex; when hour, , Take the coordinates of the first vertex.

[0106] like If so, the closed contour is identified as a small noise region and deleted. Based on the sensor array spacing Adaptive settings:

[0107] ;

[0108] In the formula, The minimum retention area threshold; This is the area filtering coefficient; This represents the spacing between the pressure sensor arrays.

[0109] After filtering small areas, the system further identifies internal closed regions. If any representative point of a closed contour lies inside another closed contour, and its area is significantly smaller than the outer contour, it can be considered an internal contour and discarded. The determination of a point within a polygon can be achieved using the ray method or the number of turns method. This step avoids interference from internal contours caused by pattern grooves or local pressure interruptions.

[0110] 2.6 The outer contour C is obtained by calculating the outer envelope.

[0111] The set of contour points retained after filtering The outer envelope was calculated to obtain the measured outer contour of the grounding imprint. In a preferred embodiment, the outer contour is generated using a convex hull algorithm. The convex hull algorithm can employ Graham's scan method, Andrew's monotonic chain method, or other equivalent algorithms. The purpose of convex hull processing is to construct a stable closed boundary from the outer boundary points, avoiding boundary discontinuities caused by local grooves, depressions, or pressure noise.

[0112] In another implementation, if it is necessary to retain the slight indentation features in the outer boundary of the actual grounding imprint, the outer contour can also be generated using the alpha shape algorithm or morphological closing operation. However, in pattern performance simulation input, if the main focus is on the overall outer envelope of the grounding area and the statistical analysis of the pattern parameters involved in the contact, the convex hull outer contour has better stability and repeatability.

[0113] Through the above processing, the final result is obtained Figure 3 The outer contour shown Compared to manual drawing methods, the technical contribution of this step lies in: standardizing contour extraction into a combined algorithm of pressure thresholding, connected tracing, area filtering, and outer envelope generation, avoiding subjective differences in manual boundary selection; at the same time, it can automatically remove small closed regions and noisy regions, making the obtained outer contour more suitable as the input boundary for subsequent mapping and simulation.

[0114] Step S3: Map the measured outer contour to the pattern unfolding scale.

[0115] Step S3 is also a key technical step in this invention. Although step S2 has already obtained the outer contour of the actual grounding imprint. However, this outer contour comes from the actual measurement coordinate system of the pressure sensor, while the tread pattern development belongs to the design coordinate system or a two-dimensional development coordinate system. Due to tire contact deformation, idealization of the tread pattern development, and differences in development scale, if directly using... When superimposed onto the pattern unfolding diagram, a mismatch in lateral scale will occur, leading to deviations in statistical parameters such as the number of pattern blocks, total side length, and pitch participation ratio.

[0116] This invention grounds the width by reading the pattern unfolding diagram. And based on the measured maximum width of the outer contour As the corresponding quantity, calculate the scaling factor. This enables the mapping from the measured outer contour to the unfolded diagram scale.

[0117] First, such as Figure 4 As shown, the grounding width is read or measured from the pattern unfolding diagram. . It can be derived from the dimensions marked in the pattern unfolding design file, or it can be calculated from the maximum distance between the left and right boundaries of the unfolding diagram on the horizontal coordinate. The unit is mm.

[0118] Secondly, calculate the outer contour. Maximum width If the outer contour The set of vertex horizontal coordinates is ,but:

[0119] ;

[0120] In the formula, Outer contour Maximum horizontal width; Outer contour The horizontal coordinates of each vertex in the middle.

[0121] Then, calculate the scaling factor:

[0122] ;

[0123] In the formula, This is the scaling factor; The ground width is for the pattern unfolding diagram; This represents the maximum width of the measured outer contour of the grounding imprint.

[0124] Outer contour any point in the middle Perform horizontal coordinate updates:

[0125] ;

[0126] In the formula, The horizontal coordinates before mapping; The horizontal coordinates after mapping; This is the scaling factor. Vertical axis. It can remain unchanged, or a vertical scaling can be further introduced according to the circumferential ratio of the unfolded diagram when needed. For the main problem addressed by this invention, namely the inconsistency between the measured lateral width of the grounding imprint and the grounding width of the pattern unfolded diagram, it is preferable to scale only the lateral coordinates to avoid excessively changing the circumferential shape of the measured grounding area.

[0127] The mapped outer contour is obtained through the above steps. . Figure 5 The mapped outer contour is shown. The effect after overlaying with the pattern unfolding diagram. Compared to the unmapped measured outer contour, The horizontal dimension is consistent with the ground width of the pattern unfolding diagram, thus enabling a more accurate definition of the actual ground area in the unfolding diagram.

[0128] Step S4: Extract pattern geometry parameters within the mapped contour-defined region.

[0129] Step S4 is used to map the outer contour. This is converted into pattern geometry input that can be used for performance simulation. This step makes a significant contribution to the creative process because it establishes a direct correlation between the measured ground boundary and the parameter statistics within the pattern unfolded diagram, so that the simulation input no longer depends on the ideal unfolded diagram boundary or manually selected areas.

[0130] First, map the outer contour. Place it in the coordinate system of the tread pattern development diagram. If the origin of the measured profile coordinates differs from the origin of the development diagram coordinates, it can be aligned by translation based on the center line of the development diagram, the center groove of the tread, the left and right boundaries, or a specified reference point. If there is a slight angular deviation in the measured profile, a rotation angle can be introduced. Perform corrections. For the contour points... The registered coordinates can be represented as:

[0131] ;

[0132] In the formula, , The coordinates after registration; The horizontal coordinates after mapping; The vertical coordinates are preserved before and after mapping; , The coordinates of the center of the contour; The rotation angle; , These represent the translation amounts in the horizontal and translational directions, respectively.

[0133] Registration error can be represented by the average distance from the contour points to the reference boundary of the unfolded diagram:

[0134] ;

[0135] In the formula, Registration error; This represents the number of contour points; For the first Coordinates of the registered contour points; Used as the reference boundary for the unfolded diagram; It represents the shortest distance from the point to the boundary.

[0136] when Less than or equal to the preset error threshold If the coordinate reference of the unfolded drawing is clear and the direction of the measured contour is consistent with the direction of the unfolded drawing, then only center translation alignment can be used without performing rotation correction.

[0137] After registration is completed, the outer contour is mapped. Extract pattern geometric parameters within a defined region. Combined with... Figure 1 A quick initial screening can be performed using patterned blocks with external positioning frames. If a certain external positioning frame is aligned with... If they do not intersect, the corresponding patterned blocks will not be included in the grounding statistics; if the external positioning frame and If they intersect, then it is further determined whether the true outline of the pattern block is located within... Inside or with Intersect. Combine. Figure 2 It can accurately calculate the outline of the patterned blocks.

[0138] For the Each patterned block has a perimeter denoted as . If there are a total If each patterned block is located within the grounding area, then the total side length of the grounding area can be expressed as:

[0139] ;

[0140] In the formula, This represents the total side length of the patterned blocks within the mapped grounding area; The number of patterned blocks included in the grounding statistics; For the first The perimeter of each patterned block.

[0141] Furthermore, the edge density can be calculated:

[0142] ;

[0143] In the formula, The edge density within the grounding area; This represents the total side length of the patterned blocks within the grounding area; To map the outer contour The area of ​​the grounding region enclosed by the grounding zone.

[0144] You can also calculate the trench area ratio:

[0145] ;

[0146] In the formula, This represents the trench area ratio; The area of ​​the trench within the grounding region; To map the outer contour The area of ​​the grounding region enclosed by the grounding zone.

[0147] The above , , , , interval sequence These together constitute the set of geometric parameters of the pattern. Compared to directly using the ideal boundary of the pattern unfolding diagram, the mapping of the outer contour is more efficient. Extracted Closer to the actual grounding range; compared to the unmapped outer contour compared to, The scale is consistent with the unfolded diagram, which can reduce the possibility of lateral omissions or miscounting of pattern blocks.

[0148] Step S5: Perform performance simulation or prediction based on pattern geometry parameters

[0149] Step S5 is used to process the set of pattern geometric parameters obtained in step S4. Input the data into the simulation model for pattern noise, handling, and / or wear performance. This step can utilize the company's existing performance prediction program, or it can employ a finite element model, acoustic model, semi-empirical model, or machine learning regression model.

[0150] The set of performance metrics can be represented as:

[0151] ;

[0152] In the formula, A set of performance metrics; Noise performance indicators; For handling performance indicators; This refers to the wear performance index.

[0153] Regarding noise performance, the total length of the patterned block edges, pitch sequence, and edge density within the grounding region affect the excitation characteristics when the patterned blocks enter and leave the contact area; regarding control performance, the number of patterned blocks, trench area ratio, and contact area shape within the grounding region affect contact stiffness and lateral response; regarding wear performance, the distribution of patterned block boundaries and the edge morphology of the contact area within the grounding region affect local slippage and wear energy distribution. Therefore, with Extraction of the defined real grounding area It can reduce geometric deviations from the input source and improve the consistency between simulation predictions and measured results.

[0154] IV. Specific Implementation Examples and Comparative Examples

[0155] The following focuses on 245 / 50R19 passenger car tires, combined with... Figures 1 to 5 This invention is described in laboratory settings. These embodiments are used to illustrate the feasibility and technical effects of the invention and do not constitute a limitation on the scope of protection.

[0156] Example 1: Automatic Extraction and Mapping of the Outer Contour of Measured Grounding Imprints

[0157] A 245 / 50R19 tire was mounted on a pressure sensor array test platform, and a static ground pressure test was conducted at a laboratory temperature of 25±2℃. The tire was inflated to the manufacturer's standard test pressure and subjected to a medium-load condition. The pressure sensor array output a ground pressure matrix, which was saved as an Excel file.

[0158] After reading the Excel file, the data reading module converts the pressure matrix into a two-dimensional pressure array. For individual missing points, 3×3 neighborhood mean interpolation was used, with the pressure unit uniformly set to Pa. Subsequently, the contour extraction module set the pressure threshold. Pa performs threshold crossing judgment on each grid edge and generates threshold nodes using interpolation. All threshold nodes are traced according to the 8-connectivity rule to form a set of closed contours. The system calculates the area of ​​each closed contour and removes those smaller than a certain value. The closed contour is obtained, and the smaller closed contours inside are deleted. Then, the convex hull of the retained point set is calculated to obtain... Figure 3 The measured outer contour of the grounding imprint is shown. .

[0159] In the pattern unfolding diagram, such as Figure 4 The reading unfolded diagram shows the ground width. mm. The system calculates the outer contour. Maximum width mm, and calculate the scaling factor:

[0160] ;

[0161] In the formula, This is the scaling factor; The ground width is for the pattern unfolding diagram; This represents the maximum width of the measured outer contour of the grounding imprint.

[0162] Substituting the data from this embodiment, we obtain System outline Execution of horizontal coordinates of each point The mapped outer contour is obtained. .Will After overlaying with the pattern unfolded diagram, we get Figure 5 The results are shown. These results demonstrate that the mapped measured outer contour can effectively cover the actual grounding area in the unfolded diagram, avoiding omissions in statistics caused by the lateral narrowness of the unmapped contour.

[0163] Repeatability data from Example 1

[0164] Table 1 presents the automatic extraction and mapping results of repeated measurements taken from two tires of the same specification under medium-load conditions. For the number of points on the outer contour, The time taken for the automated process from reading the Excel file to outputting the mapped outline and overlay plot.

[0165]

[0166] As can be seen from Table 1, under the same conditions... Under anchoring, the measured maximum width of the outer contour The repetitive fluctuations are small, and the scaling factor is small. The value stabilized between 1.0441 and 1.0467, with automatic processing taking approximately 103 to 118 seconds. Compared to manual screenshotting and outlining, which typically takes about 2 hours, this invention significantly reduces manual processing time.

[0167] Example 2: Extraction of pattern parameters within the mapped outer contour region

[0168] Based on the mapped outer contour obtained in Example 1 Extract the number of pattern blocks in the grounding area from the pattern unfolded diagram. Total side length To demonstrate the geometric input correction effect of this invention, the following comparison scheme was set up:

[0169] Comparative Example A: The ideal outer boundary of the pattern development diagram is directly used as the boundary of the grounding area; Comparative Example B: The measured outer contour is used. However, without scaling mapping, the statistical parameters are directly superimposed onto the unfolded diagram; Example: The mapped outer contour of the present invention As the boundary of the grounding area; Reference Ref: The boundary, which is finely outlined by hand and manually verified, is used as a reference for error evaluation.

[0170] The relative error of geometric input is calculated using the following formula:

[0171] ;

[0172] In the formula, The relative error is the geometric input. The geometric statistic to be evaluated; This is the geometric statistic corresponding to the reference boundary.

[0173] Table 2 shows a comparison of pattern geometry input parameters under different boundary strategies.

[0174]

[0175] As shown in Table 2, Comparative Example A, due to the use of an ideal boundary in the unfolded diagram, tends to overestimate the number of patterned blocks and the total side length within the grounding area; Comparative Example B, although using the measured outer contour, suffers from an underestimation of the lateral boundary due to the lack of scale mapping, resulting in understated statistics; the embodiments of this invention adopt... back, and The errors were significantly reduced, indicating that the present invention can improve the authenticity and consistency of pattern geometry input.

[0176] Example 3: Performance Simulation Error Verification

[0177] Input the pattern geometry parameters obtained from different schemes in Table 2 into the same noise, handling, and wear prediction program, and compare them with laboratory test values ​​or calibration values. The error is calculated using the following formula:

[0178] ;

[0179] In the formula, This represents the relative error in performance simulation. For simulating or predicting output values; These are laboratory test values ​​or bench calibration values.

[0180] Table 3 shows a comparison of performance simulation errors under different boundary strategies.

[0181]

[0182] As shown in Table 3, compared with Comparative Examples A and B, the simulation errors of the embodiments of the present invention are significantly reduced in terms of noise, handling, and wear. This result demonstrates that the present invention not only improves contour extraction efficiency but also reduces simulation input deviation through realistic ground boundary mapping, thereby improving performance prediction accuracy.

[0183] Comparative Example A: Ideal boundary using pattern development diagram

[0184] Comparative Example A directly uses the ideal boundary in the tread pattern development diagram as the boundary of the ground contact area. This method eliminates the need for actual measurement of the ground contact imprint's outer contour and mapping processing. However, since the tread pattern development diagram is a two-dimensional ideal development diagram, it does not reflect the actual ground contact deformation of the tire under load. Therefore, its ground contact area is usually larger or its shape is inconsistent with the actual ground contact. As can be seen from Table 2, Comparative Example A... and All values ​​were higher than the reference values, resulting in larger errors in the prediction of noise, handling, and wear.

[0185] Comparative Example B: Using unmapped measured outer contour

[0186] Comparative Example B extracts the outer contour from measured pressure data. But not based on and Instead of performing scaling mapping, directly... This is superimposed onto the pattern development diagram. While this scheme considers the measured grounding boundary, it neglects the scale difference between the measured coordinate system and the pattern development diagram coordinate system. As shown in Table 2, Comparative Example B... and All values ​​are lower than the reference value, indicating a problem of lateral omission in the statistical analysis of the unmapped outer contour. As shown in Table 3, although the simulation error is lower than that of comparative example A, it is still significantly higher than that of the embodiment of the present invention.

[0187] The difference between this embodiment and Comparative Example A is that this invention does not directly use the ideal unfolded boundary, but extracts the true grounding outer contour from measured pressure data; the difference between this embodiment and Comparative Example B is that this invention further uses... The scaling factor is calculated, and the measured outer contour is mapped to the pattern unfolding diagram scale before parameter statistics are performed. Because it simultaneously incorporates both "automatic extraction of the measured outer contour" and "mapping to the pattern unfolding diagram scale," this invention can ensure consistency between the actual ground boundary and the unfolding diagram coordinates.

[0188] Combination Figures 1 to 5 As can be seen from Tables 1 to 3, this invention achieves the measured outer contour of the grounding imprint through pressure threshold isopleth node extraction, closed contour tracking, area filtering, and outer envelope calculation. Automatic extraction; ground width by reading the pattern unfolded diagram. Calculate the maximum width of the measured outer contour. And obtain the scaling factor This achieves the mapping from the measured outer contour to the pattern unfolding scale; by mapping the outer contour... Extracting the set of geometric parameters of the pattern within a limited area This achieves a direct correlation between the actual grounding boundary and the simulation input of the pattern performance.

[0189] Compared to traditional manual drawing methods, this invention reduces the processing time for a single tire contact patch boundary from approximately 2 hours to approximately 2 minutes, significantly reducing manual labor. Compared to directly using the ideal boundary of the tread pattern development diagram, this invention can reduce the overestimation of geometric input in the contact patch area. Compared to unmapped measured outer contours, this invention can eliminate the inconsistency in lateral scale between the measured coordinate system and the development diagram coordinate system. Experimental data shows that using this invention to map the outer contour... Afterwards, the tread geometry input error can be controlled to within about 1%, and the simulation errors of noise, handling and wear are significantly reduced, thereby improving the accuracy, consistency and engineering repeatability of tire tread performance simulation.

[0190] 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.

[0191] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0192] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0193] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0194] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0195] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0196] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0197] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

Claims

1. A method for improving the simulation accuracy of pattern performance based on automatic extraction and mapping of the outer contour of measured grounding imprints, characterized in that, The method includes the following steps: S1, collect the measured tire ground pressure data and read it as a two-dimensional pressure array M; S2, constructing M as a grounded pressure grid using the pressure sensor array spacing d, and setting a pressure threshold. When the coordinates of the two endpoints of any grid edge , Corresponding pressure satisfy or At this point, contour nodes are determined between the two endpoints, and the coordinates (X,Y) of the threshold nodes are obtained using cubic spline interpolation. Then, connectivity tracing is performed on all threshold nodes to form at least one closed contour. The closed contour is then filtered to remove small closed regions and areas smaller than the area threshold. The closed region is defined, and the convex hull is calculated for the retained contour point set to obtain the measured outer contour C of the grounding imprint; S3, read the ground width TAW of the pattern unfolded diagram and calculate the maximum width B of the outer contour C, then calculate the scaling factor: ; The horizontal coordinates x of each point in the outer contour C are updated as follows: ; Obtain the outer contour of the mapped grounding imprint '; S4, outer contour Register with the coordinate system of the pattern unfolding diagram to determine the set of pattern geometric parameters G within the grounding region defined by C'; S5 uses G as the geometric input to perform simulations or predictions of pattern noise, handling, and / or wear performance to output performance metrics.

2. The method as described in claim 1, characterized in that, The measured grounding pressure data in step S1 is collected by a pressure sensor array and stored in a table file, where each cell in the table file corresponds to the pressure value of a pressure grid node. The table file is parsed into a two-dimensional pressure array M, and interpolation is performed on missing values. The table file is an Excel file or an equivalent expression; the interpolation is bilinear interpolation or interpolation based on the neighborhood mean; the neighborhood is centered on the missing point. The window, where m is an odd number not less than 3.

3. The method as described in claim 1, characterized in that, The pressure grid in step S2 has a grid side length equal to the array spacing d, and the pressure value of each grid node is given by the array elements of the two-dimensional pressure array M; And / or, in step S2, when the pressure at both ends of the mesh edge... Pressure threshold at different locations When both sides, by the pressure field Interpolation is performed along the grid edge to obtain the desired result. The threshold node coordinates (X, Y); where, This is a pressure field lookup function defined by a two-dimensional pressure array M; And / or, the cubic spline interpolation in step S2 includes: parameterizing the candidate node sequence with the node index as parameter t, constructing cubic spline functions for X(t) and Y(t) respectively, and finding the values ​​that satisfy... The parameter t is used to obtain the threshold node coordinates (X,Y); X(t) and Y(t) are spline interpolation functions.

4. The method as described in claim 1, characterized in that, The convex hull calculation in step S2 uses the Graham scan algorithm, the Andrew monotonic chain algorithm, or the equivalent convex hull algorithm to output the smallest convex polygon containing the set of preserved contour points as the outer contour C. And / or, the connectivity tracing in step S2 adopts a 4-connectivity or 8-connectivity rule, starting from any threshold node and connecting the threshold nodes sequentially according to their adjacent relationships until returning to the starting point, forming a closed contour path; wherein, 4-connectivity connects only the adjacent nodes in the top, bottom, left and right; 8-connectivity connects the adjacent nodes in the top, bottom, left and right and diagonally. And / or, the filtering in step S2 includes: calculating the area A of each closed contour and deleting the area. Closed contours and closed contours located inside the outer contour, only retain those that satisfy... The set of points on the outer closed contour is used for subsequent convex hull calculation.

5. The method as described in claim 1, characterized in that, The maximum width mentioned in step S3 Determine by the following formula: ； Where x is the lateral coordinate of each point in the outer contour C; B and TAW use the same unit of length; And / or, the mapping described in step S3 only scales the horizontal coordinate x to compensate for the difference in horizontal dimension between the pattern unfolding and the measured grounding imprint, and the mapped outer contour C' obtained after scaling keeps the vertical coordinate y of the point unchanged.

6. The method as described in claim 1, characterized in that, The registration in step S4 includes: using the center line or boundary line of the pattern unfolding as a reference, performing a translation on the mapped outer contour C'. and rotation angle Correction is performed to ensure that the registration error is no greater than the threshold. The registration error is the average point-to-boundary distance or the Hausdorff distance. And / or, the set of pattern geometry parameters G in step S4 includes at least the number of pattern blocks. Total side length , interval sequence and the set of patterned blocks perimeter .

7. The method as described in claim 1, characterized in that, The performance indicators mentioned in step S5 include at least one or more of the following: noise indicators, handling indicators, and wear indicators, which are output by the corresponding simulation models respectively.

8. A tire contact patch contour extraction and comparison / mapping system, characterized in that, The system is used to implement the method according to any one of claims 1-7, including a data reading module, a contour extraction module, a contour mapping module and a performance simulation module; wherein, the data reading module is used to execute step S1; the contour extraction module is used to execute step S2; the contour mapping module is used to execute steps S3 and S4; and the performance simulation module is used to execute step S5 and output performance indicators.

9. 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 steps of the method described in any one of claims 1-7.

10. 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 steps of the method described in any one of claims 1-7.

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