Portable shoe last back body bridge position measuring method

Abstract

The present application relates to the technical field of shoe tree, and discloses a portable shoe tree rear body bridge position measuring method, which comprises the following steps: taking the rear body bridge position information with the highest proportion as the rear body bridge position information of the corresponding mother tree of the heel height, and manufacturing the mother tree; manufacturing the curved reference surface of the curved surface of the rear body bottom plate of the mother tree, and embedding a plurality of pressure sensors on the bottom surface of the rear body bridge position measuring device; placing the mother tree on the upper part of the rear body bridge position measuring device, collecting standard pressure distribution information through the pressure sensors; placing the rear body bridge position measuring device on the bottom of the shoe tree to be measured, collecting the fitting image information of the rear body bridge position measuring device and the bottom of the shoe tree and the pressure distribution information collected by the pressure sensors, calculating the fitting degree according to the fitting image information and the pressure distribution information, and obtaining the standard degree of the shoe tree according to the fitting degree. The present application not only improves the accuracy and efficiency of measurement, but also better reflects the comfort and adaptability of the shoe tree.

Description

Technical Field

[0001] This invention relates to the field of shoe last technology, and more specifically, to a portable method for measuring the back bridge position of a shoe last. Background Technology

[0002] The importance of shoe last and back panel standards is reflected in the following aspects: (1) Structural design basis: Shoe last and back panel templates are an important reference for footwear structural design, providing designers with a basic template for designing soles, heels, midsoles, and insoles; (2) Ensuring comfort: Correct shoe last and back panel templates can ensure that the size and shape of the shoes are suitable for different users' foot shapes, thereby providing better comfort and support; (3) Improving production efficiency: Standardized shoe last and back panel templates help improve efficiency in the production process because they can be quickly replicated and applied to large-scale production; (4) Guaranteeing product quality: Following standard shoe last and back panel templates can ensure the consistency of product quality and reduce shoe quality problems caused by inaccurate last shapes. In summary, shoe last and back panel standards are crucial for ensuring the design quality, production efficiency, and consumer comfort of shoes. Important points for back panel inspection include heel convexity and sole convexity.

[0003] There are two existing technical testing methods: one is the national testing method, and the other is the manual standard caliper testing method. The national standard testing method includes two operation methods: (1) Measurement of heel convexity: The reference points for measuring heel convexity are the outer edge point and the inner edge point of the heel, that is, the line connecting the inner and outer edges of the heel is used as the reference to measure the degree of convexity at the heel convexity position. Vernier calipers and steel ruler are used together. The measurement points are M, M2, and M. When operating, fix the shoe last with the shoe facing upward, and align the two measuring feet of the vernier caliper with the two measuring points M and M2. Then place the small steel ruler on the heel convexity point M and attach it vertically to the caliper, and read the height value between the steel ruler and the caliper. Subtract the height of the steel ruler from the height value of the measuring feet to obtain the heel convexity value. The dotted line in the figure is the measurement reference line. Note: The measurement of heel convexity is not related to the heel convexity point M. (2) Sole Convexity: The reference points for measuring sole concavity are the forefoot convexity point and the heel convexity point. That is, the line connecting the heel convexity point and the forefoot convexity point is used as the reference to measure the degree of concavity at the waist dimple. A vernier caliper and a steel ruler are used together. The measurement points are W, M, and the waist dimple width line, as shown in the figure. During operation, the shoe last is fixed upright. The two measuring feet of the vernier caliper are aligned with points M and W. Then, the small steel ruler is placed at the waist dimple width line and perpendicularly attached to the caliper. The height between the steel ruler and the caliper is read. Subtracting the height of the measuring foot from the height of the steel ruler yields the sole concavity value. The caliper used in manual measurement is a standard template designed based on the last's shape. It is a fixture in shoe last design, used to measure and compare the last's outline to complete the production of the standard last. Shoe lasts are categorized into bottom arc cards, last bottom horizontal arc cards, back arc cards, side plate cards, and overall edge cards. When comparing shoe lasts, only one line can be compared. However, every part of a shoe last is a three-dimensional (surface structure), so using only a single line to measure or determine a surface is unscientific. Whether it's a national standard testing method or a manual testing method, it can only actually test one line of the shoe last. The actual shoe last is a three-dimensional surface; using lines to control or judge the standardization of a surface is unscientific and unreliable.

[0004] Therefore, it is necessary to provide a portable method for measuring the back bridge of a shoe last to solve the problem that the existing method of using a single line to measure and determine whether the entire surface of the back bridge of a shoe last is standard is unscientific. Summary of the Invention

[0005] In view of this, the present invention proposes a portable method for measuring the back bridge position of a shoe last, which aims to solve the problem that the existing method of using a single line to measure and determine whether the entire surface of the back bridge position of a shoe last is standard is unscientific.

[0006] This invention proposes a portable method for measuring the back bridge position of a shoe last, comprising:

[0007] Collect back bridge information of several shoe lasts with the same heel height but different lasts, compare the back bridge information of the same heel height, and take the back bridge information with the highest proportion as the back bridge information of the corresponding master last for that heel height, and make the master last.

[0008] The curved reference surface of the rear axle position measuring device is made according to the curved surface of the rear bottom plate of the mother last. The heel height of the rear axle position measuring device is made according to the heel height of the mother last. The bottom length of the rear axle position measuring device is taken according to the national standard rear length. Several pressure sensors are embedded in the bottom surface of the rear axle position measuring device to complete the fabrication of the rear axle position measuring device.

[0009] The mother last is placed on the upper part of the rear axle position measuring device, and standard pressure distribution information is collected by the pressure sensor;

[0010] The back bridge measuring device is placed at the bottom of the shoe last to be measured. The fitting image information between the back bridge measuring device and the bottom of the shoe last and the pressure distribution information collected by the pressure sensor are collected. The fitting degree is calculated based on the fitting image information and the pressure distribution information. The standard degree of the shoe last is obtained based on the fitting degree.

[0011] Furthermore, when collecting back bridge information from several shoe lasts with the same heel height but different heel heights, and comparing the back bridge information for the same heel height, the process includes:

[0012] Using 3D scanning technology, the surfaces of several shoe lasts with the same heel height but different back bridge positions are transformed into the same mesh model, with each mesh node corresponding to a 3D coordinate;

[0013] Construct a sequence of back bridge information for each shoe last based on three-dimensional coordinates: Hij = (A1, A2, A3, ..., An), where Hij represents the j-th back bridge information sequence for shoe last with heel height i, Ak = (Xk, Yk, Zk), where Ak represents the k-th three-dimensional coordinate point in Hij, k = 1, 2, 3, ..., n; Xk represents the x-axis coordinate of the k-th three-dimensional coordinate point in Hij, Yk represents the y-axis coordinate of the k-th three-dimensional coordinate point in Hij, and Zk represents the z-axis coordinate of the k-th three-dimensional coordinate point in Hij.

[0014] In this process, the parameters in the back bridge position information sequence of each shoe last are recorded sequentially in Hij according to the same direction of the shoe last.

[0015] Furthermore, the step of using the rear bridge position information with the highest proportion as the rear bridge position information of the corresponding mother last when making the mother last includes:

[0016] A similarity threshold is set, and a clustering algorithm is used to divide all the shoe last back bridge information sequences into several clusters. In each cluster, the similarity between any two shoe last back bridge information sequences is greater than or equal to the similarity threshold.

[0017] Select the cluster with the most sequences of bridge information on the back of the shoe last, and calculate the three-dimensional coordinates of each grid node corresponding to the mother last using the following formula:

[0018] Ck=((X1+X2+…+Xq) / q, (Y1+Y2+…+Yq) / q, (Z1+Z2+…+Zq) / q);

[0019] In the above formula, Ck represents the k-th three-dimensional coordinate point of the last back bridge position information, q represents the number of three-dimensional coordinate points in the cluster with the most last back bridge position information sequences, Xq represents the X-axis coordinate of the q-th three-dimensional coordinate point in the cluster with the most last back bridge position information sequences, Yq represents the Y-axis coordinate of the q-th three-dimensional coordinate point in the cluster with the most last back bridge position information sequences, and Zq represents the Z-axis coordinate of the q-th three-dimensional coordinate point in the cluster with the most last back bridge position information sequences.

[0020] Furthermore, when the similarity of any two shoe last back bridge position information sequences within each cluster is greater than or equal to the similarity threshold, it includes:

[0021] The similarity of the back bridge information sequences of any two shoe lasts within each cluster is calculated using the following formula:

[0022]

[0023] In the above formula, D represents the similarity of the back bridge information sequence of any two shoe lasts within each cluster, (Xb, Yb, Zb) represents one of the three-dimensional coordinate points within the cluster, and (Xc, Yc, Zc) represents another three-dimensional coordinate point within the cluster.

[0024] Furthermore, when using the rear length according to national standards as the bottom surface length of the rear axle position measuring device, it includes:

[0025] The national standard specifies a rear length of 138mm, which is used as the bottom length of the rear bridge position measuring device.

[0026] Furthermore, when placing the mother last on top of the rear axle position measuring device and collecting standard pressure distribution information through a pressure sensor, the process includes:

[0027] Collect pressure information from each pressure sensor, and construct a standard pressure distribution sequence Y = (y1, y2, y3, ..., yp) for the mother last based on the pressure information;

[0028] Where yw represents the pressure information of the w-th pressure sensor, w = 1, 2, 3, ..., p.

[0029] Furthermore, when placing the rear bridge measuring device on the bottom of the shoe last to be measured, and collecting the contact image information between the rear bridge measuring device and the bottom of the shoe last and the pressure distribution information collected by the pressure sensor, the process includes:

[0030] Collect pressure distribution information when each shoe last is placed on the back bridge measuring device, and construct a pressure distribution sequence Ya=(ya1,ya2,ya3,…,yap) for each shoe last;

[0031] Where Ya represents the pressure distribution sequence of the a-th shoe last, yaw represents the pressure information of the w-th pressure sensor of the a-th shoe last, and w = 1, 2, 3, ..., p;

[0032] Images are captured when each shoe last to be measured is placed on the rear bridge measuring device;

[0033] The contours of the shoe last and the back bridge measuring device in the image were extracted using an edge detection algorithm;

[0034] Based on the edge detection results and threshold segmentation, the image is divided into contact regions and gap regions, and the area of ​​the gap regions is calculated.

[0035] Furthermore, the calculation of the fit degree based on the fit image information and pressure distribution information includes:

[0036] Calculate the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last, and calculate the fit based on the similarity and the area of ​​the gap region; wherein, the fit is calculated according to the following formula:

[0037] When the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last is set to 1, and the area of ​​the gap region is 0, the fit is full marks, and the full marks of fit are equal to 100.

[0038] T = α*100 + β*100;

[0039] In the above formula, T represents the fit, α represents the influence coefficient of the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last, and β represents the influence coefficient of the area of ​​the gap region. The values ​​of α and β are both in the range of 0-0.5.

[0040] Furthermore, the calculation of the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last includes:

[0041]

[0042] In the above formula, S represents the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last, yaw represents the pressure information of the w-th pressure sensor of the a-th shoe last, yw represents the pressure information of the w-th pressure sensor, w = 1, 2, 3, ..., p; p represents the total number of pressure sensors of the rear bridge position measuring device.

[0043] Furthermore, when determining the standard degree of the shoe last based on the fit, it includes:

[0044] A first fit and a second fit are set, wherein the first fit is greater than the second fit;

[0045] If the fit is 100, then the shoe last is a first-class standard;

[0046] If the fit is greater than the first fit but less than 100, then the shoe last is a secondary standard.

[0047] If the fit is less than or equal to the first fit and greater than or equal to the second fit, then the shoe last is a third-level standard.

[0048] If the fit is less than the second fit, then the shoe last is a level four standard;

[0049] Among them, the standard level of shoe lasts, from high to low, is as follows: Level 1, Level 2, Level 3, and Level 4.

[0050] Compared with existing technologies, the advantages of this invention are as follows: First, by collecting back bridge information from several shoe lasts of the same heel height but different heel heights, and comparing and selecting the back bridge information with the highest proportion as the standard data for the master last, this invention can accurately represent the characteristics of a shoe last with a specific heel height, ensuring that the production of the master last is more in line with actual needs. This big data analysis-based method avoids the limitations of a single model and can reflect the common characteristics of different shoe last designs. Second, the back bridge measuring device is precisely designed, based on the back sole surface curvature, heel height, and national standard back length of the master last, ensuring high precision and standardization of the measuring instrument and providing a reliable benchmark for subsequent measurements. Furthermore, the integrated pressure sensor can collect the pressure distribution between the shoe last and the measuring device in real time, and combine it with image information to calculate the fit, providing a quantitative evaluation index for shoe last design. This method not only improves the accuracy and efficiency of measurement but also better reflects the comfort and fit of the shoe last, providing a scientific basis for footwear design and production. Attached Figure Description

[0051] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0052] Figure 1 A flowchart of a portable shoe last back bridge measurement method provided in an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram showing the shoe last placed above the rear bridge measuring device, as provided in an embodiment of the present invention. Detailed Implementation

[0054] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0055] In some embodiments of this application, see Figure 1 As shown, this embodiment provides a portable method for measuring the back bridge position of a shoe last, including the following steps:

[0056] S100. Collect back bridge information of several shoe lasts with the same heel height but different heel heights, compare the back bridge information of the same heel height, and take the back bridge information with the highest proportion as the back bridge information of the corresponding mother last for that heel height, and make the mother last.

[0057] S200. Based on the curved surface of the rear bottom plate of the mother last, make the curved reference surface of the rear axle position measuring device. Based on the heel height of the mother last, make the heel height of the rear axle position measuring device. Based on the rear length of the national standard, take the bottom length of the rear axle position measuring device as the bottom length. Embed several pressure sensors on the bottom surface of the rear axle position measuring device to complete the fabrication of the rear axle position measuring device.

[0058] S300: Place the mother last on the upper part of the rear axle position measuring device and collect standard pressure distribution information through the pressure sensor;

[0059] S400: Place the back bridge measuring device on the bottom of the shoe last to be measured, collect the fit image information between the back bridge measuring device and the bottom of the shoe last, and the pressure distribution information collected by the pressure sensor. Calculate the fit degree based on the fit image information and pressure distribution information, and obtain the standard degree of the shoe last based on the fit degree.

[0060] Understandably, this invention first collects back bridge information from several shoe lasts of the same heel height but different heel heights, and then selects the back bridge information with the highest percentage as the standard data for the master last. This accurately represents the characteristics of a shoe last with a specific heel height, ensuring that the production of the master last better meets actual needs. This big data analysis-based method avoids the limitations of a single model and can reflect the common characteristics of different shoe last designs. Secondly, the back bridge measuring device is precisely designed, based on the back sole surface curvature, heel height, and national standard back length of the master last, ensuring high precision and standardization of the measuring instrument and providing a reliable benchmark for subsequent measurements. Furthermore, the integrated pressure sensor can collect the pressure distribution between the shoe last and the measuring device in real time, and combine it with image information to calculate the fit, providing a quantitative evaluation index for shoe last design. This method not only improves the accuracy and efficiency of measurement but also better reflects the comfort and fit of the shoe last, providing a scientific basis for footwear design and production. Specifically, Figure 2 This is a diagram showing the shoe last placed above the rear bridge measuring device.

[0061] In some embodiments of this application, when collecting back bridge information of several shoe lasts with the same heel height but different heel heights and comparing the back bridge information of the same heel height, the process includes:

[0062] Using 3D scanning technology, the surfaces of several shoe lasts with the same heel height but different back bridge positions are transformed into the same mesh model, with each mesh node corresponding to a 3D coordinate;

[0063] Construct a sequence of back bridge information for each shoe last based on three-dimensional coordinates: Hij = (A1, A2, A3, ..., An), where Hij represents the j-th back bridge information sequence for shoe last with heel height i, Ak = (Xk, Yk, Zk), where Ak represents the k-th three-dimensional coordinate point in Hij, k = 1, 2, 3, ..., n; Xk represents the x-axis coordinate of the k-th three-dimensional coordinate point in Hij, Yk represents the y-axis coordinate of the k-th three-dimensional coordinate point in Hij, and Zk represents the z-axis coordinate of the k-th three-dimensional coordinate point in Hij.

[0064] In this process, the parameters in the back bridge position information sequence of each shoe last are recorded sequentially in Hij according to the same direction of the shoe last.

[0065] In some embodiments of this application, the rear bridge position information with the highest proportion is used as the rear bridge position information of the corresponding mother last for that heel height. When manufacturing the mother last, the process includes:

[0066] A similarity threshold is set, and a clustering algorithm is used to divide all the shoe last back bridge information sequences into several clusters. In each cluster, the similarity between any two shoe last back bridge information sequences is greater than or equal to the similarity threshold.

[0067] Select the cluster with the most sequences of bridge information on the back of the shoe last, and calculate the three-dimensional coordinates of each grid node corresponding to the mother last using the following formula:

[0068] Ck=((X1+X2+…+Xq) / q, (Y1+Y2+…+Yq) / q, (Z1+Z2+…+Zq) / q);

[0069] In the above formula, Ck represents the k-th three-dimensional coordinate point of the last back bridge position information, q represents the number of three-dimensional coordinate points in the cluster with the most last back bridge position information sequences, Xq represents the X-axis coordinate of the q-th three-dimensional coordinate point in the cluster with the most last back bridge position information sequences, Yq represents the Y-axis coordinate of the q-th three-dimensional coordinate point in the cluster with the most last back bridge position information sequences, and Zq represents the Z-axis coordinate of the q-th three-dimensional coordinate point in the cluster with the most last back bridge position information sequences.

[0070] In some embodiments of this application, when the similarity of any two shoe last back bridge position information sequences within each cluster is greater than or equal to a similarity threshold, it includes:

[0071] The similarity of the back bridge information sequences of any two shoe lasts within each cluster is calculated using the following formula:

[0072]

[0073] In the above formula, D represents the similarity of the back bridge information sequence of any two shoe lasts within each cluster, (Xb, Yb, Zb) represents one of the three-dimensional coordinate points within the cluster, and (Xc, Yc, Zc) represents another three-dimensional coordinate point within the cluster.

[0074] Understandably, this invention provides a precise and scientific method for extracting the back bridge information of shoe lasts and creating master lasts by combining 3D scanning technology with clustering algorithms. First, 3D scanning technology is used to convert the back bridge of the shoe last into a mesh model, and each 3D coordinate point is precisely recorded in an information sequence, ensuring data accuracy and consistency. Second, by setting a similarity threshold, a clustering algorithm is used to divide the back bridge information sequences of different shoe lasts into multiple clusters, and the cluster with the most data is selected to determine the back bridge of the master last. By calculating the average of all 3D coordinates within a cluster, the back bridge data of the master last representing the characteristics of that heel height can be obtained, thus ensuring that the master last has good representativeness among various shoe last samples. This process not only avoids the bias of traditional manual selection methods but also improves the automation and accuracy of data processing through algorithms. Furthermore, the combination of clustering algorithms and similarity calculations makes the selection of back bridge information more in line with actual usage needs, effectively improving the efficiency and accuracy of shoe last customization and production, and providing a more scientific basis for the research and development and optimization of footwear products.

[0075] In some embodiments of this application, when the rear length is used as the bottom surface length of the rear axle position measuring device according to the national standard, the following is included:

[0076] The national standard specifies a rear length of 138mm, which is used as the bottom length of the rear bridge position measuring device.

[0077] In some embodiments of this application, when placing the mother last on top of the rear axle position measuring device and collecting standard pressure distribution information through a pressure sensor, the process includes:

[0078] Collect pressure information from each pressure sensor, and construct a standard pressure distribution sequence Y = (y1, y2, y3, ..., yp) for the mother last based on the pressure information;

[0079] Where yw represents the pressure information of the w-th pressure sensor, w = 1, 2, 3, ..., p.

[0080] In some embodiments of this application, when placing the rear bridge measuring device at the bottom of the shoe last to be measured and collecting the contact image information between the rear bridge measuring device and the bottom of the shoe last and the pressure distribution information collected by the pressure sensor, the process includes:

[0081] Collect pressure distribution information when each shoe last is placed on the back bridge measuring device, and construct a pressure distribution sequence Ya=(ya1,ya2,ya3,…,yap) for each shoe last;

[0082] Where Ya represents the pressure distribution sequence of the a-th shoe last, yaw represents the pressure information of the w-th pressure sensor of the a-th shoe last, and w = 1, 2, 3, ..., p;

[0083] Images are captured when each shoe last to be measured is placed on the rear bridge measuring device;

[0084] The contours of the shoe last and the back bridge measuring device in the image were extracted using an edge detection algorithm;

[0085] Based on the edge detection results and threshold segmentation, the image is divided into contact regions and gap regions, and the area of ​​the gap regions is calculated.

[0086] In some embodiments of this application, calculating the fit degree based on the fit image information and pressure distribution information includes:

[0087] Calculate the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last, and calculate the fit based on the similarity and the area of ​​the gap region; wherein, the fit is calculated according to the following formula:

[0088] When the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last is set to 1, and the area of ​​the gap region is 0, the fit is full marks, and the full marks of fit are equal to 100.

[0089] T = α*100 + β*100;

[0090] In the above formula, T represents the fit, α represents the influence coefficient of the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last, and β represents the influence coefficient of the area of ​​the gap region. The values ​​of α and β are both in the range of 0-0.5.

[0091] In some embodiments of this application, calculating the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last includes:

[0092]

[0093] In the above formula, S represents the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last, yaw represents the pressure information of the w-th pressure sensor of the a-th shoe last, yw represents the pressure information of the w-th pressure sensor, w = 1, 2, 3, ..., p; p represents the total number of pressure sensors of the rear bridge position measuring device.

[0094] Understandably, this embodiment significantly improves the accuracy and reliability of last back bridge measurement through standardized national back length, precise pressure sensor data acquisition, and image processing technology. First, using 138mm as the bottom length of the back bridge measuring device, this national standard-based design ensures the uniformity and standardization of the measuring device across various last applications, providing a reliable benchmark for accurate testing and comparison of footwear products. Second, pressure sensors are used to collect pressure distribution information between the last and the measuring device in real time. By constructing a pressure distribution sequence, the fit between the last and the mother last can be quantified, providing a scientific basis for the comfort and adaptability of last design. Combined with edge detection algorithms for image processing, the contact area and gap area can be accurately divided, further analyzing the fit between the last bottom and the measuring device, thereby meticulously evaluating the overall design of the last. By calculating the similarity of the pressure distribution sequence and the area of ​​the gap area, a fit score is comprehensively derived, effectively improving the comprehensiveness and accuracy of the measurement. This method not only quantifies the fit between the shoe last and the mother last, but also reduces human error and improves production efficiency through standardized and automated measurement processes. Furthermore, it provides important support for the customization and optimization design of footwear products, helping to improve the quality and competitiveness of footwear products in the market.

[0095] In some embodiments of this application, when determining the standard degree of the shoe last based on the fit, the following methods are included:

[0096] Set a first fit degree and a second fit degree, where the first fit degree is greater than the second fit degree;

[0097] If the fit is 100, the shoe last is of Grade 1 standard;

[0098] If the fit is greater than the first fit but less than 100, the shoe last is a second-level standard.

[0099] If the fit is less than or equal to the first fit and greater than or equal to the second fit, the shoe last is a third-level standard.

[0100] If the fit is less than the second fit, the shoe last is a level four standard;

[0101] Among them, the standard level of shoe lasts, from high to low, is as follows: Level 1, Level 2, Level 3, and Level 4.

[0102] Understandably, this invention categorizes shoe lasts into four levels—Level 1, Level 2, Level 3, and Level 4—based on varying degrees of fit, accurately reflecting the matching degree between the shoe last and the mother last. Level 1 represents a perfect fit, achieving a fit of 100%, ensuring optimal comfort and adaptability. As the fit decreases, the standard level of the shoe last gradually declines, allowing manufacturers to manage shoe lasts in tiers according to different needs, thereby improving production precision and adaptability. By introducing the settings of a first and second fit degree, it is possible to more flexibly address different fit levels, precisely classify the quality levels of shoe lasts, facilitate product selection, optimization, and customization, and enhance the standardized management of footwear products.

[0103] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. 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 goods 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.

[0104] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods 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.

[0105] 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.

[0106] 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.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A portable method for measuring the bridge position of the back of a shoe last, characterized in that, include: Collect back bridge information of several shoe lasts with the same heel height but different lasts, compare the back bridge information of the same heel height, and take the back bridge information with the highest proportion as the back bridge information of the corresponding master last for that heel height, and make the master last. The curved reference surface of the rear axle position measuring device is made according to the curved surface of the rear bottom plate of the mother last. The heel height of the rear axle position measuring device is made according to the heel height of the mother last. The bottom length of the rear axle position measuring device is taken according to the national standard rear length. Several pressure sensors are embedded in the bottom surface of the rear axle position measuring device to complete the fabrication of the rear axle position measuring device. The mother last is placed on the upper part of the rear axle position measuring device, and standard pressure distribution information is collected by the pressure sensor; The back bridge measuring device is placed at the bottom of the shoe last to be measured. The fitting image information between the back bridge measuring device and the bottom of the shoe last and the pressure distribution information collected by the pressure sensor are collected. The fitting degree is calculated based on the fitting image information and the pressure distribution information. The standard degree of the shoe last is obtained based on the fitting degree.

2. The portable shoe last back bridge measurement method according to claim 1, characterized in that, The process of collecting back bridge information from several shoe lasts with the same heel height but different heel heights, and comparing the back bridge information for the same heel height, includes: Using 3D scanning technology, the surfaces of several shoe lasts with the same heel height but different back bridge positions are transformed into the same mesh model, with each mesh node corresponding to a 3D coordinate; Construct a sequence of back bridge information for each shoe last based on three-dimensional coordinates: Hij = (A1, A2, A3, ..., An), where Hij represents the j-th back bridge information sequence for shoe last with heel height i, Ak = (Xk, Yk, Zk), where Ak represents the k-th three-dimensional coordinate point in Hij, k = 1, 2, 3, ..., n; Xk represents the x-axis coordinate of the k-th three-dimensional coordinate point in Hij, Yk represents the y-axis coordinate of the k-th three-dimensional coordinate point in Hij, and Zk represents the z-axis coordinate of the k-th three-dimensional coordinate point in Hij. In this process, the parameters in the back bridge position information sequence of each shoe last are recorded sequentially in Hij according to the same direction of the shoe last.

3. The portable shoe last back bridge measurement method according to claim 2, characterized in that, The process of using the rear bridge position information with the highest proportion as the rear bridge position information of the corresponding mother last for that heel height, when making the mother last, includes: A similarity threshold is set, and a clustering algorithm is used to divide all the shoe last back bridge information sequences into several clusters. In each cluster, the similarity between any two shoe last back bridge information sequences is greater than or equal to the similarity threshold. Select the cluster with the most information sequences of the shoe last's back bridge position, and calculate the three-dimensional coordinates of each grid node corresponding to the mother last using the following formula: Ck=((X1+X2+…+Xq) / q, (Y1+Y2+…+Yq) / q, (Z1+Z2+…+Zq) / q); In the above formula, Ck represents the k-th three-dimensional coordinate point of the last back bridge position information, q represents the number of three-dimensional coordinate points in the cluster with the most last back bridge position information sequences, Xq represents the X-axis coordinate of the q-th three-dimensional coordinate point in the cluster with the most last back bridge position information sequences, Yq represents the Y-axis coordinate of the q-th three-dimensional coordinate point in the cluster with the most last back bridge position information sequences, and Zq represents the Z-axis coordinate of the q-th three-dimensional coordinate point in the cluster with the most last back bridge position information sequences.

4. The portable shoe last back bridge measurement method according to claim 3, characterized in that, When the similarity of any two shoe last back bridge position information sequences within each cluster is greater than or equal to the similarity threshold, it includes: The similarity of the back bridge information sequences of any two shoe lasts within each cluster is calculated using the following formula: In the above formula, D represents the similarity of the back bridge information sequence of any two shoe lasts within each cluster, (Xb, Yb, Zb) represents one of the three-dimensional coordinate points within the cluster, and (Xc, Yc, Zc) represents another three-dimensional coordinate point within the cluster.

5. The portable shoe last back bridge measurement method according to claim 4, characterized in that, When using the rear length as the bottom surface length of the rear bridge position measuring device according to the national standard, it includes: The national standard specifies a rear length of 138mm, which is used as the bottom length of the rear bridge position measuring device.

6. The portable shoe last back bridge measurement method according to claim 5, characterized in that, When placing the mother last on top of the rear axle position measuring device and collecting standard pressure distribution information through a pressure sensor, the process includes: Collect pressure information from each pressure sensor, and construct a standard pressure distribution sequence Y = (y1, y2, y3, ..., yp) for the mother last based on the pressure information; Where yw represents the pressure information of the w-th pressure sensor, w = 1, 2, 3, ..., p.

7. The portable shoe last back bridge measurement method according to claim 6, characterized in that, When placing the rear bridge measuring device on the bottom of the shoe last to be measured, and collecting the contact image information between the rear bridge measuring device and the bottom of the shoe last and the pressure distribution information collected by the pressure sensor, the process includes: Collect pressure distribution information when each shoe last is placed on the back bridge measuring device, and construct a pressure distribution sequence Ya=(ya1,ya2,ya3,…,yap) for each shoe last; Where Ya represents the pressure distribution sequence of the a-th shoe last, yaw represents the pressure information of the w-th pressure sensor of the a-th shoe last, and w = 1, 2, 3, ..., p; Images are captured when each shoe last to be measured is placed on the rear bridge measuring device; The contours of the shoe last and the back bridge measuring device in the image were extracted using an edge detection algorithm; Based on the edge detection results and threshold segmentation, the image is divided into contact regions and gap regions, and the area of ​​the gap regions is calculated.

8. The portable shoe last back bridge measurement method according to claim 7, characterized in that, The calculation of the fit degree based on the fit image information and pressure distribution information includes: Calculate the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last, and calculate the fit based on the similarity and the area of ​​the gap region; wherein, the fit is calculated according to the following formula: When the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last is set to 1, and the area of ​​the gap region is 0, the fit is full marks, and the full marks of fit are equal to 100. T＝α*100+β*100； In the above formula, T represents the fit, α represents the influence coefficient of the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last, and β represents the influence coefficient of the area of ​​the gap region. The values ​​of α and β are both in the range of 0-0.

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9. The portable shoe last back bridge measurement method according to claim 8, characterized in that, The calculation of the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last includes: In the above formula, S represents the similarity between the pressure distribution sequence of the shoe last and the standard pressure distribution sequence of the mother last, yaw represents the pressure information of the w-th pressure sensor of the a-th shoe last, yw represents the pressure information of the w-th pressure sensor, w = 1, 2, 3, ..., p; p represents the total number of pressure sensors of the rear bridge position measuring device.

10. The portable method for measuring the back bridge position of a shoe last according to claim 8, characterized in that, When determining the standard degree of the shoe last based on the fit, it includes: A first fit and a second fit are set, wherein the first fit is greater than the second fit; If the fit is 100, then the shoe last is a first-class standard; If the fit is greater than the first fit but less than 100, then the shoe last is a secondary standard. If the fit is less than or equal to the first fit and greater than or equal to the second fit, then the shoe last is a third-level standard. If the fit is less than the second fit, then the shoe last is a level four standard; Among them, the standard level of shoe lasts, from high to low, is as follows: Level 1, Level 2, Level 3, and Level 4.

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