Leather embossing process

Abstract

The invention discloses a leather embossing process, relates to the technical field of leather production monitoring, and solves the technical problems that a systematic and scientific method is lacked and the embossing process is difficult to accurately control. The Pearson's correlation coefficient is used for calculating the correlation degree to determine the standard embossing parameters, the method does not depend on experience purely any more, a high-definition camera and a machine vision technology are used for obtaining and recognizing the surface image of the target object, an abnormal area can be found in time, and after an abnormal reason is determined, the detection accuracy is improved. According to the method, the influence on the embossing effect is analyzed in combination with historical data, influence factors are calculated, then targeted adjustment and calibration are conducted on the standard embossing parameters, calibration and adjustment are conducted on the standard embossing parameters based on the influence factors, and deviation in the production process can be corrected.

Description

Technical Field

[0001] The invention relates to the technical field of leather production monitoring, in particular to a leather embossing process. Background Art

[0002] Printed embossed leather is widely used in the production of clothing, shoes, luggage, handbags, toys, furniture, packaging boxes, handicrafts, decorations and other products in the market.

[0003] According to the publication number CN110987954B, a method and system for eliminating blind spots in leather surface defect detection are disclosed, which belongs to the field of machine vision surface detection technology. The method provides a machine vision detection system with orthogonal composite of linear array and planar array, adopts side-entry planar array system for auxiliary detection, and compares the detection results of the two to obtain the final detection result, so that the online monitoring of leather can detect various isotropic defects such as creases, bubbles, perforations, and various anisotropic defects such as uneven matte, ink, and embossing in the direction of leather transmission, and can also detect various anisotropic defects such as uneven matte, ink, and embossing in the direction perpendicular to the leather transmission direction, so that the recognition rate of defects such as embossing and ink on the leather surface can reach 100%, greatly reducing the defective rate of products.

[0004] The above patent eliminates the blind spot of defect detection, greatly reduces the number of cameras used, and reduces production costs. However, in the production of some existing leather embossing, the traditional embossing process often relies on experience to determine the embossing parameters, lacks a systematic and scientific method, and is difficult to accurately control the embossing process for different leather materials, texture requirements, and various complex production conditions, resulting in unstable embossing quality and low production efficiency. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a leather embossing process, which solves the problem of lack of systematic and scientific methods and difficulty in accurately controlling the embossing process.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: leather embossing process, including:

[0007] An embossing parameter acquisition unit is used to acquire parameter requirements and transmit the acquired parameter requirements to an embossing parameter analysis unit;

[0008] An embossing parameter analysis unit is used to analyze the acquired parameter requirements, determine standard embossing parameters in combination with historical data, and perform embossing on the leather according to the standard embossing parameters, and perform quality analysis on the obtained leather to generate analysis results, wherein the analysis results include normal results and abnormal results, and then transmit the abnormal results to the abnormal processing unit, and transmit the normal results to the calibration information output unit;

[0009] An abnormality processing unit is used to process the acquired parameter abnormality analysis signal, obtain a surface image of the target object, identify the surface image, determine the specific cause of the abnormality of the target object, and transmit the specific cause to the comprehensive calibration analysis unit;

[0010] The comprehensive calibration analysis unit is used to analyze the specific reasons obtained, adjust and calibrate the standard embossing parameters by analyzing the influence of the specific reasons on the embossing effect, obtain calibration information based on the influence analysis of the complexity of the texture, and transmit the calibration information to the calibration information output unit.

[0011] As a further solution of the present invention, the parameter requirements include texture, embossing temperature, embossing speed and pressure.

[0012] As a further solution of the present invention, the specific method of the embossing parameter analysis unit to determine the standard embossing parameters is:

[0013] Obtain parameter requirements and historical data, and filter the historical data based on the parameter requirements to obtain pre-selected historical data, and filter the standard embossing parameters based on the obtained pre-selected historical data;

[0014] The correlation between the parameter requirements and the pre-selected historical data is calculated, and the correlation is reflected by the Pearson correlation coefficient. At the same time, the pre-selected historical data with the largest correlation is selected as the standard, and the standard embossing parameters are generated based on the embossing parameters in the pre-selected historical data.

[0015] As a further solution of the present invention, the embossing parameter analysis unit performs quality analysis on the obtained leather to generate analysis results in the following specific manner:

[0016] The obtained embossed leather is recorded as a target object, and the production texture of the target object is obtained and recorded as a target texture, and then the target texture is compared with the parameter requirement;

[0017] If the target texture is the same as the parameter requirement, it means that the standard embossing parameters are normal and do not need to be adjusted. At the same time, the standard embossing parameters are transmitted to the calibration information output unit. If the target texture is different from the parameter requirement, it means that the standard embossing parameters are abnormal and need to be adjusted. At the same time, a parameter abnormality analysis signal is generated and transmitted to the abnormality processing unit.

[0018] As a further solution of the present invention, the specific manner in which the abnormality processing unit processes the acquired parameter abnormality analysis signal is:

[0019] The surface image of the target object is acquired, and the surface image is identified to obtain the abnormal area. Then the historical data is acquired, and the abnormal parameters corresponding to different abnormal conditions in the historical data are acquired, and the abnormal features corresponding to the abnormal area are obtained. Then the abnormal features are matched with the abnormal parameters, and the specific causes of the abnormal areas are screened, and the specific causes are transmitted to the comprehensive calibration analysis unit.

[0020] As a further solution of the present invention, the specific method for the comprehensive calibration analysis unit to analyze the specific cause is:

[0021] Obtain the specific reasons and historical data at the same time, and analyze the influence of the specific reasons on the embossing effect in combination with the historical data, obtain the data corresponding to the same situation as the specific reasons in the historical data, and analyze the corresponding influence under different numerical specific reasons, calculate the corresponding influence factor based on the influence of different numerical specific reasons, and analyze the influence factor at the same time.

[0022] As a further solution of the present invention, the specific method of analyzing the influencing factors by the comprehensive calibration analysis unit is:

[0023] The texture depth L of the target object is obtained, and the corresponding texture depth in the parameter requirement is obtained and recorded as L1. At the same time, the texture complexity of the target object is evaluated to obtain a texture complexity value, wherein the texture complexity can be specifically classified into four levels: simple, relatively complex, complex, and very complex. At the same time, different levels of texture complexity are assigned, and the assigned texture complexity is recorded as a texture complexity value.

[0024] As a further solution of the present invention, the comprehensive calibration analysis unit obtains the calibration information based on the influence analysis of the texture complexity in a specific manner as follows:

[0025] Obtain the pressure value in the parameter requirement as P0, and calculate the depth ratio as k, where the depth ratio is given by the formula The calculated pressure P is obtained by substituting the obtained parameters into the formula P=[P0×(1+k)×α], where α is the preset proportional coefficient;

[0026] At the same time, the texture complexity value of the target object is obtained and recorded as Yn, and n=1, 2, 3 and 4. At the same time, the weight coefficients corresponding to the texture complexity value Yn are obtained and recorded as a1, a2, ..., and then the obtained calculated pressure and the texture complexity value Yn are substituted into the formula Pz=(P×Y1×a1)+(P×Y2×a2)+...+(P×Yn×an) to calculate the calibration pressure Pz, and at the same time generate calibration information, and transmit the calibration information to the calibration information output unit.

[0027] The present invention provides a leather embossing process. Compared with the prior art, it has the following beneficial effects:

[0028] The present invention screens historical data based on parameter requirements and uses the Pearson correlation coefficient to calculate the correlation to determine the standard embossing parameters. It no longer relies solely on experience. It uses high-definition cameras and machine vision technology to acquire and identify the surface image of the target object, and can promptly discover abnormal areas. After determining the cause of the abnormality, it combines historical data to analyze its impact on the embossing effect and calculates the influencing factors, and then performs targeted adjustment and calibration of the standard embossing parameters. Calibration and adjustment of the standard embossing parameters based on these influencing factors can correct deviations in the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a block diagram of the system principle of the present invention;

[0030] Figure 2 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] For example, see Figure 1 and Figure 2 The present application provides a leather embossing process, which is controlled and implemented by a corresponding embossing system, wherein the embossing system includes an embossing parameter acquisition unit, an embossing parameter analysis unit, an exception processing unit, a comprehensive calibration analysis unit and a calibration information output unit, and the above functional units are unidirectionally electrically connected.

[0033] The embossing parameter acquisition unit is used to obtain parameter requirements and transmit the obtained parameter requirements to the embossing parameter analysis unit. The parameter requirements are expressed as parameter requirements corresponding to the current production, where the parameter requirements specifically include texture, embossing temperature, embossing speed and pressure.

[0034] The embossing parameter analysis unit is used to analyze the acquired parameter requirements, determine the standard embossing parameters in combination with historical data, and emboss the leather according to the standard embossing parameters. At the same time, the quality of the obtained leather is analyzed to generate analysis results, wherein the analysis results include normal results and abnormal results. The abnormal results are then transmitted to the abnormal processing unit, and the normal results are transmitted to the calibration information output unit.

[0035] Specifically, parameter requirements and historical data are obtained, and the historical data is screened based on the parameter requirements to obtain pre-selected historical data, wherein the screening method is: historical data that meets the parameter requirements is screened out, for example, the parameter requirement is that the leather embossing pattern is a complex pattern, and the embossing parameters corresponding to the complex pattern in the historical data are further obtained and marked as pre-selected historical data, and standard embossing parameters are screened based on the obtained pre-selected historical data, and the specific screening method is: the correlation between the parameter requirements and the pre-selected historical data is calculated, and the calculation of the correlation here is determined by the Pearson correlation coefficient, and the pre-selected historical data with the largest correlation is selected as the standard, and the standard embossing parameters are generated based on the embossing parameters in the pre-selected historical data;

[0036] Taking pattern clarity as the main concern indicator (the parameter requirements require pattern clarity to be above 4 points), calculate the Pearson correlation coefficient between parameters such as pressure, temperature, speed, and pattern clarity and complex pattern requirements;

[0037] Assume that after calculation, it is found that in a certain set of historical data, when the pressure is 2MPa, the temperature is 100℃, and the speed is 4m / min, the deviation value from the pattern clarity is small, and the comprehensive correlation with the parameter requirements calculated by the Pearson correlation coefficient is the highest (for example, the correlation of pressure is 0.8, the correlation of temperature is 0.7, and the correlation of speed is 0.6. The comprehensive correlation is obtained by weighted average. Assuming that the weights are 0.4, 0.3, and 0.3 respectively, the comprehensive correlation is 0.74). Then the embossing parameters in this set of data (pressure 2MPa, temperature 100℃, speed 4m / min) are used as standard embossing parameters.

[0038] Then, the leather is embossed according to the obtained standard embossing parameters, and the obtained embossed leather is recorded as the target object, and the production texture of the target object is obtained and recorded as the target texture. Then, the target texture is compared with the parameter requirements. If the target texture is the same as the parameter requirements, after careful comparison and analysis, it is found that the target texture is completely consistent with the complex texture specified in the parameter requirements, the lines are clear and delicate, and the interweaving method and depth of the pattern are in line with expectations, showing a very good three-dimensional sense and texture. This shows that the standard embossing parameters perform normally in this production, which means that the standard embossing parameters are normal and do not need to be adjusted. At the same time, the standard embossing parameters are transmitted to the calibration information output unit. If the target texture is different from the parameter requirements, it is assumed that when checking the target texture, it is found that the lines of some patterns are not clear enough, the texture depth in some places is shallow, and the overall texture effect is different from the complex texture specified in the parameter requirements, which means that the standard embossing parameters are abnormal and need to be adjusted. At the same time, a parameter abnormality analysis signal is generated and transmitted to the abnormality processing unit.

[0039] A calibration information output unit is used to display the acquired standard embossing parameters to the corresponding operator.

[0040] Embodiment 2, as Embodiment 2 of the present invention, is implemented on the basis of Embodiment 1, and differs from Embodiment 1 in that:

[0041] The abnormality processing unit is used to process the acquired parameter abnormality analysis signal, obtain the surface image of the target object, identify the surface image to determine the specific cause of the abnormality of the target object, and transmit the specific cause to the comprehensive calibration analysis unit.

[0042] Use a high-definition camera to collect all-round, high-resolution images of the surface of the target object (embossed leather). For example, an industrial-grade high-definition camera with a resolution of [X]×[Y] (such as 2048×1536 pixels) is installed in a suitable position to ensure that every detail of the leather surface can be clearly captured. At the same time, the camera's shooting parameters need to be adjusted according to the characteristics of the leather and the complexity of the embossed pattern. For example, the exposure time is set to milliseconds (such as 50 milliseconds) to adapt to different lighting conditions, ensure that the image brightness and contrast are moderate, and make the embossed pattern clearly visible. The surface image of the object is acquired and the surface image is identified using machine vision technology. For example, the median filter algorithm is used to remove noise in the image, and the filter window size is set to [specific value] × [specific value] (such as 3 × 3 pixels) to maintain the clarity of the edge of the pattern. Then, the embossed pattern is separated from the background by the threshold segmentation algorithm. The threshold selection can use an adaptive threshold method to automatically determine the optimal threshold based on the local features of the image to adapt to the differences in light reflection of different leather materials and colors. At the same time, the surface images with abnormalities are screened and recorded as abnormal areas. Then, the abnormal areas are segmented. The specific analysis method is as follows: historical data is obtained, and at the same time, abnormal parameters corresponding to different abnormal situations in the historical data are obtained. For example, cases with blurred patterns due to excessive pressure are grouped into one group, and cases with insufficient three-dimensional patterns due to excessively low temperature are grouped into another group. For each group of abnormal situations, the corresponding abnormal parameter features are extracted, such as the average value, maximum value, and amplitude exceeding the normal range of the pressure in the excessively high pressure group; the average value, minimum value, and difference from the standard temperature in the excessively low temperature group, and the abnormal features corresponding to the abnormal area are extracted. Then, the abnormal features are compared with the abnormal The specific reasons here may include embossing time, embossing pressure, embossing speed and embossing temperature. To illustrate, assume that the characteristics of the current abnormal area are that the pattern lines become thicker and the spacing becomes smaller, and some patterns become blurred. Through the analysis of historical data, it is found that when the pressure is too high (the average pressure in the historical data exceeds the normal range MPa, such as 2.8MPa, and the normal range is 2-2.5MPa), similar pattern lines will become thicker and blurred, and the specific reasons obtained will be transmitted to the comprehensive calibration analysis unit.

[0043] A comprehensive calibration analysis unit is used to analyze the specific reasons obtained, adjust and calibrate the standard embossing parameters by analyzing the influence of the specific reasons on the embossing effect, obtain calibration information based on the influence analysis of the complexity of the texture, and transmit the calibration information to the calibration information output unit.

[0044] Obtain the specific reason, obtain historical data at the same time, and analyze the influence of the specific reason on the embossing effect in combination with the historical data. The specific analysis method is: obtain the data corresponding to the same situation as the specific reason in the historical data, and analyze the corresponding influence under different numerical specific reasons, and calculate the corresponding influence factor by combining the influence of different numerical specific reasons. Assume that through the previous detection and analysis process, it is determined that the specific reason for the current leather embossing abnormality is that the embossing temperature is too high. For example, the actual detected embossing temperature is 130°C, and according to the standard process requirements, the appropriate temperature range should be between 100-120°C. At the same time, the data of the past 50 embossing productions are collected, and 10 of them have abnormal temperatures (temperature exceeds the normal range);

[0045] Assume that the temperatures in the 10 abnormal temperature data are 125℃, 132℃, 128℃, 135℃, 127℃, 130℃, 131℃, 126℃, 129℃, and 133℃, respectively. The corresponding leather materials are cowhide and sheepskin, with a thickness of 2-4 mm, a pressure of 2-3 MPa, and a speed of 3-5 m / min. The embossing effect evaluation includes pattern clarity score (out of 10 points), three-dimensional score (out of 10 points), etc. For each different temperature value, analyze its specific impact on the embossing effect;

[0046] For example, when the temperature is 125°C, the difference in pattern clarity score is 8-7=1 point, and the difference in stereoscopic score is 7-6=1 point. These score differences are normalized to obtain relative score differences. Assuming that after normalization, the relative score difference of pattern clarity is 0.125 (1÷8), and the relative score difference of stereoscopic score is 0.143 (1÷7). Assuming that after calculation, when the temperature is between 125°C and 130°C, the average relative score difference of pattern clarity is 0.11, and the average relative score difference of stereoscopic score is 0.13; when the temperature is between 131°C and 135°C, the average relative score difference of pattern clarity is 0.25, and the average relative score difference of stereoscopic score is 0.32.

[0047] The standard embossing parameters are calibrated and adjusted based on the obtained influencing factors, and the numerical value corresponding to the influencing factor is taken as the pressure data for analysis, and the texture depth L of the target object is obtained, and the texture depth L is expressed as the texture height obtained by the current embossing, and the corresponding texture depth in the parameter requirement is obtained and recorded as L1. At the same time, the texture complexity of the target object is evaluated to obtain the texture complexity value, wherein the texture complexity can be specifically classified into four levels: simple (such as straight line texture), relatively complex (such as simple cross texture), complex (such as irregular interwoven texture), and very complex (such as textures containing multiple shapes and directions). At the same time, different levels of texture complexity are assigned, for example, the complexity coefficient of simple texture is set to 1, the relatively complex texture is set to 1.3, the complex texture is set to 1.6, and the very complex texture is set to 2.0, and the texture complexity after assignment is recorded as the texture complexity value.

[0048] Then obtain the pressure value in the parameter requirement and record it as P0, where P0 represents the initial pressure, and calculate the depth ratio and record it as k, where the depth ratio is given by the formula The calculated pressure P is obtained by substituting the obtained parameters into the formula P=[P0×(1+k)×α], where α is the preset proportional coefficient;

[0049] At the same time, the texture complexity value of the target object is obtained and recorded as Yn, and n=1, 2, 3 and 4, specifically n here represents the corresponding different level assignments, and the weight coefficients corresponding to the texture complexity value Yn are obtained and recorded as a1, a2, ..., and then the obtained calculation pressure and the texture complexity value Yn are calculated to obtain the calibration pressure, and the specific calculation formula is Pz=(P×Y1×a1)+(P×Y2×a2)+...+(P×Yn×an), the calibration pressure Pz is calculated according to the formula, and the calibration information is generated and transmitted to the calibration information output unit.

[0050] A calibration information output unit is used to display the acquired calibration information to the corresponding operator.

[0051] Embodiment 3, as the embodiment 3 of the present invention, focuses on combining the implementation processes of embodiment 1 and embodiment 2 for implementation.

[0052] Some of the data in the above formulas are dimensionless and numerically calculated. Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0053] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. Leather embossing process, characterized in that: The following steps are involved: Step 1: The leather embossing process is processed by the embossing technology in the prior art, and the required parameters are analyzed by the embossing control system, wherein the embossing control system includes: A parameter collection unit, used to collect parameter requirements during the embossing process and transmit the acquired parameter requirements to the embossing parameter analysis unit; An embossing parameter analysis unit is used to analyze the acquired parameter requirements, determine standard embossing parameters in combination with historical data, and perform embossing on the leather according to the standard embossing parameters, and perform quality analysis on the obtained leather to generate analysis results, wherein the analysis results include normal results and abnormal results, and then transmit the abnormal results to the abnormal processing unit, and transmit the normal results to the calibration information output unit; An abnormality processing unit is used to process the acquired parameter abnormality analysis signal, obtain a surface image of the target object, identify the surface image, determine the specific cause of the abnormality of the target object, and transmit the specific cause to the comprehensive calibration analysis unit; A comprehensive calibration analysis unit is used to analyze the specific reasons obtained, adjust and calibrate the standard embossing parameters by analyzing the influence of the specific reasons on the embossing effect, obtain calibration information based on the influence analysis of the complexity of the texture, and transmit the calibration information to the calibration information output unit; Step 2: Display the obtained calibration information to the corresponding operator through the calibration information output unit.

2. The leather embossing process according to claim 1, characterized in that: The parameter requirements include texture, embossing temperature, embossing speed and pressure.

3. The leather embossing process according to claim 1, characterized in that: The specific method of determining the standard embossing parameters by the embossing parameter analysis unit is as follows: Obtain parameter requirements and historical data, and filter the historical data based on the parameter requirements to obtain pre-selected historical data, and filter the standard embossing parameters based on the obtained pre-selected historical data; The correlation between the parameter requirements and the pre-selected historical data is calculated, and the correlation is reflected by the Pearson correlation coefficient. At the same time, the pre-selected historical data with the largest correlation is selected as the standard, and the standard embossing parameters are generated based on the embossing parameters in the pre-selected historical data.

4. The leather embossing process according to claim 1, characterized in that: The specific method of the embossing parameter analysis unit performing quality analysis on the obtained leather to generate the analysis result is: The obtained embossed leather is recorded as a target object, and the production texture of the target object is obtained and recorded as a target texture, and then the target texture is compared with the parameter requirement; If the target texture is the same as the parameter requirement, it means that the standard embossing parameters are normal and do not need to be adjusted. At the same time, the standard embossing parameters are transmitted to the calibration information output unit. If the target texture is different from the parameter requirement, it means that the standard embossing parameters are abnormal and need to be adjusted. At the same time, a parameter abnormality analysis signal is generated and transmitted to the abnormality processing unit.

5. The leather embossing process according to claim 1, characterized in that: The specific manner in which the abnormality processing unit processes the acquired parameter abnormality analysis signal is as follows: The surface image of the target object is acquired, and the surface image is identified to obtain the abnormal area. Then the historical data is acquired, and the abnormal parameters corresponding to different abnormal conditions in the historical data are acquired, and the abnormal features corresponding to the abnormal area are obtained. Then the abnormal features are matched with the abnormal parameters, and the specific causes of the abnormal areas are screened, and the specific causes are transmitted to the comprehensive calibration analysis unit.

6. The leather embossing process according to claim 1, characterized in that: The specific way in which the comprehensive calibration analysis unit analyzes the specific cause is as follows: Obtain the specific reasons and historical data at the same time, and analyze the influence of the specific reasons on the embossing effect in combination with the historical data, obtain the data corresponding to the same situation as the specific reasons in the historical data, and analyze the corresponding influence under different numerical specific reasons, calculate the corresponding influence factor based on the influence of different numerical specific reasons, and analyze the influence factor at the same time.

7. The leather embossing process according to claim 6, characterized in that: The specific way in which the comprehensive calibration analysis unit analyzes the influencing factors is as follows: The texture depth L of the target object is obtained, and the corresponding texture depth in the parameter requirement is obtained and recorded as L1. At the same time, the texture complexity of the target object is evaluated to obtain a texture complexity value, wherein the texture complexity can be specifically classified into four levels: simple, relatively complex, complex, and very complex. At the same time, different levels of texture complexity are assigned, and the assigned texture complexity is recorded as a texture complexity value.

8. The leather embossing process according to claim 1, characterized in that: The specific method in which the comprehensive calibration analysis unit obtains the calibration information based on the influence analysis of the texture complexity is: Obtain the pressure value in the parameter requirement as P0, and calculate the depth ratio as k, where the depth ratio is given by the formula The calculated pressure P is obtained by substituting the obtained parameters into the formula P=[P0×(1+k)×α], where α is the preset proportional coefficient; At the same time, the texture complexity value of the target object is obtained and recorded as Yn, and n=1, 2, 3 and 4. At the same time, the weight coefficients corresponding to the texture complexity value Yn are obtained and recorded as a1, a2, ..., and then the obtained calculated pressure and the texture complexity value Yn are substituted into the formula Pz=(P×Y1×a1)+(P×Y2×a2)+...+(P×Yn=an) to calculate the calibration pressure Pz, and at the same time generate calibration information, and transmit the calibration information to the calibration information output unit.

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