Corrugated board strength detection method for corrugated packaging box production

Abstract

The invention relates to the technical field of data processing, in particular to a corrugated board strength detection method for corrugated packaging box production, which comprises the following steps: acquiring water content data, actual edge pressure strength and predicted edge pressure strength of a corrugated board under different environment humidity; a prediction error is obtained according to the difference between the actual edge pressure strength and the predicted edge pressure strength in the corrugated board production process, and the environment humidity is screened to obtain the environment humidity to be analyzed; according to the change relation of the water content data along with the environmental humidity, and in combination with the incidence relation of the pressure on the corrugated board and the deformation of the corrugated board, obtaining the influence degree of the corrugated board under each to-be-analyzed environmental humidity; according to the incidence relation between the environment humidity and the prediction error, the predicted edge pressure strength is corrected in combination with the affected degree, and online strength detection of the corrugated board is achieved. According to the method, the adaptability of the online strength detection operation of the corrugated board to the actual working condition is enhanced, and the overall prediction precision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and in particular to a method for detecting the strength of corrugated paperboard used in the production of corrugated packaging boxes. Background Art

[0002] As the primary transport packaging material, corrugated packaging plays an important role in protecting goods, facilitating handling, and reducing transportation costs. As the core structural material of packaging boxes, the physical strength of corrugated cardboard directly affects the overall load-bearing capacity, compressive strength, and service life of the box. In recent years, to meet market demands for green, environmentally friendly, lightweight, and high-performance products, the raw materials, structural design, and manufacturing processes of corrugated cardboard have been continuously optimized, but this has also led to the increased difficulty of controlling strength. Currently, in the production process of corrugated packaging boxes, technologies such as non-contact sensors, machine vision, or artificial intelligence algorithms are used to quickly evaluate the mechanical strength properties of corrugated cardboard, enabling real-time monitoring and feedback of the strength of the corrugated cardboard, preventing unqualified products from entering subsequent processes, and improving production efficiency and stability.

[0003] In existing technologies, in order to quickly discover problems, adjust the process in time, and avoid batch losses, it is necessary to detect the strength of corrugated cardboard in real time during the production process. Since destructive testing like in a laboratory is not possible, a combination of online detection (real-time monitoring) and offline sampling (laboratory verification) is adopted. By measuring the thickness and flute structure of the cardboard, combined with a mathematical model based on historical laboratory data, the strength of the corrugated cardboard is estimated in real time.

[0004] However, moisture is a key factor in the fluctuation of corrugated cardboard's strength. The humidity in the corrugated packaging box production workshop is easily affected by environmental factors such as the rainy season, and the corrugated cardboard may become damp, resulting in a reduction in its actual strength. Therefore, when making predictions, the existing laboratory mathematical model lacks analysis of the impact of environmental humidity on the strength of corrugated cardboard, resulting in low model accuracy and low accuracy of the online strength test results of corrugated cardboard. Summary of the Invention

[0005] In order to solve the technical problem that the strength prediction results of existing laboratory mathematical models are of low accuracy, resulting in low accuracy of online strength test results of corrugated cardboard, the purpose of the present invention is to provide a corrugated cardboard strength test method for corrugated packaging box production. The technical solution adopted is as follows: Obtain the moisture content data of corrugated cardboard under different ambient humidity, as well as the actual edge crush strength and predicted edge crush strength; According to the difference between the actual edge compression strength and the predicted edge compression strength of the corrugated board at each ambient humidity during the production process of the corrugated board, a prediction error at each ambient humidity is obtained, and the ambient humidity is screened based on the prediction error to obtain the ambient humidity to be analyzed; Based on the relationship between the moisture content data of the corrugated cardboard and the ambient humidity under each environmental humidity to be analyzed, combined with the correlation between the pressure on the corrugated cardboard and the deformation of the corrugated cardboard, the influence of the moisture content data on the corrugated cardboard is analyzed to obtain the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed; According to the correlation between different ambient humidity and corresponding prediction errors, combined with the degree of influence, the predicted edge compression strength of the corrugated cardboard under the ambient humidity to be analyzed is corrected, and the corrugated cardboard is subjected to online strength testing based on the corrected predicted edge compression strength of the corrugated cardboard.

[0006] Preferably, the method of analyzing the influence of the moisture content data on the corrugated cardboard according to the relationship between the moisture content data of the corrugated cardboard and the ambient humidity under each ambient humidity to be analyzed, in combination with the correlation between the pressure on the corrugated cardboard and the deformation of the corrugated cardboard, and obtaining the degree of influence of the corrugated cardboard under each ambient humidity to be analyzed, specifically includes: Obtain different pressure data and corresponding displacement data of the corrugated cardboard under each environmental humidity to be analyzed, wherein the displacement data represents the deformation of the corrugated cardboard caused by the pressure; According to the variation relationship between the pressure data and displacement data corresponding to the corrugated cardboard under each environmental humidity to be analyzed and the deviation from the variation relationship under normal environmental humidity, a characteristic deviation index of each environmental humidity to be analyzed is obtained; According to the relationship between the moisture content data of the corrugated cardboard under each environmental humidity to be analyzed and the environmental humidity, the fitted moisture content of the corrugated cardboard under each environmental humidity to be analyzed is obtained; According to the difference in characteristic deviation index between each environmental humidity to be analyzed and other environmental humidity, combined with the difference in corresponding fitted moisture content, the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed is obtained.

[0007] Preferably, the characteristic deviation index of each ambient humidity to be analyzed is obtained based on the variation relationship between the pressure data and displacement data corresponding to the corrugated cardboard under each ambient humidity to be analyzed and the deviation from the variation relationship under normal ambient humidity, specifically including: The pressure data corresponding to the corrugated cardboard under each environmental humidity to be analyzed constitutes a pressure data sequence under each environmental humidity to be analyzed, the displacement data corresponding to the corrugated cardboard under each environmental humidity to be analyzed constitutes a displacement data sequence under each environmental humidity to be analyzed, and the Pearson correlation coefficient between the pressure data sequence and the displacement data sequence under each environmental humidity to be analyzed is used as the characteristic correlation coefficient under each environmental humidity to be analyzed; The characteristic correlation coefficient corresponding to the normal ambient humidity is obtained, and the absolute value of the difference between each ambient humidity to be analyzed and the characteristic correlation coefficient under the normal ambient humidity is used as the characteristic deviation index of each ambient humidity to be analyzed.

[0008] Preferably, obtaining the fitted moisture content of the corrugated cardboard at each ambient humidity to be analyzed according to the relationship between the moisture content data of the corrugated cardboard at each ambient humidity to be analyzed and the ambient humidity specifically includes: The humidity of each environment to be analyzed is used as the horizontal axis, and the moisture content data of the corrugated cardboard under each environment to be analyzed is used as the vertical axis. A linear fit is performed to obtain the humidity-moisture content fitting relationship; In the humidity-moisture content fitting relationship, the fitting moisture content corresponding to the corrugated cardboard under the humidity of the environment to be analyzed is determined based on the humidity of each environment to be analyzed.

[0009] Preferably, the method of obtaining the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed based on the difference in characteristic deviation index between each environmental humidity to be analyzed and other environmental humidity, in combination with the difference in corresponding fitted moisture content, specifically includes: Obtaining reference ambient humidity within the neighborhood of each ambient humidity to be analyzed, wherein the reference ambient humidity is arranged in a preset order; The absolute value of the difference between the characteristic deviation indexes under each two adjacent reference ambient humidity is used as the first characteristic difference under each two adjacent reference ambient humidity; the absolute value of the difference between the fitted water content under each two adjacent reference ambient humidity is used as the second characteristic difference under each two adjacent reference ambient humidity; Based on the negative correlation coefficient between the first characteristic difference and the second characteristic difference, the characteristic attenuation degree under each two adjacent reference ambient humidity is determined; and the average of all characteristic attenuation degrees within the neighborhood range of each ambient humidity to be analyzed is used as the degree of influence of the corrugated cardboard under each ambient humidity to be analyzed.

[0010] Preferably, the predicted edge compression strength of the corrugated cardboard under the environmental humidity to be analyzed is corrected according to the correlation between different environmental humidity and corresponding prediction errors and in combination with the degree of influence, specifically including: According to the difference between different ambient humidity and corresponding prediction error, the correlation degree between prediction error and ambient humidity is obtained; Using the correlation degree and the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed, weighting the predicted edge compression strength of the corrugated cardboard under each environmental humidity to be analyzed to obtain a strength adjustment degree; The difference between the predicted edge compression strength of the corrugated cardboard under each environmental humidity to be analyzed and the strength adjustment degree is used as the corrected edge compression strength of the corrugated cardboard under each environmental humidity to be analyzed.

[0011] Preferably, obtaining the correlation between the prediction error and the ambient humidity according to the difference between different ambient humidity and the corresponding prediction error specifically includes: Arrange each ambient humidity in ascending order to form an ambient humidity sequence, and form a prediction error sequence with the prediction error corresponding to each ambient humidity in the ambient humidity sequence; The negative correlation normalization coefficient of the DTW distance between the ambient humidity series and the prediction error series is calculated to obtain the degree of correlation between the prediction error and the ambient humidity.

[0012] Preferably, the predicted edge compression strength of the corrugated cardboard under each environmental humidity to be analyzed is weighted using the correlation degree and the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed to obtain the strength adjustment degree, specifically including: The product of the normalized value of the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed, the correlation degree, and the predicted edge compression strength of the corrugated cardboard under the corresponding environmental humidity to be analyzed is calculated as the strength adjustment degree under each environmental humidity to be analyzed.

[0013] Preferably, obtaining the prediction error at each ambient humidity according to the difference between the actual edge compression strength and the predicted edge compression strength of the corrugated board at each ambient humidity during the corrugated board production process specifically includes: The absolute value of the difference between the actual edge crush strength and the predicted edge crush strength of the corrugated board at each ambient humidity during the corrugated board production process is taken as the prediction error at each ambient humidity.

[0014] Preferably, the screening of the ambient humidity based on the prediction error to obtain the ambient humidity to be analyzed specifically includes: The prediction error at each ambient humidity during the corrugated cardboard production process is normalized, and the ambient humidity corresponding to the normalized prediction error being greater than a preset error threshold is used as the ambient humidity to be analyzed.

[0015] The embodiments of the present invention have at least the following beneficial effects: The present invention first measures prediction errors by analyzing the differences between actual data and predicted data under different ambient humidity conditions during the online production of corrugated cardboard. This effectively identifies situations where the basic prediction results are affected by ambient humidity, providing a data foundation for subsequent dynamic humidity compensation. Then, by analyzing the changing relationship between ambient humidity and the moisture content data of the corrugated cardboard, combined with the relationship between the pressure exerted on the corrugated cardboard and the cardboard deformation, a model for the influence of the moisture content of the corrugated cardboard on the cardboard strength is established. This model can reveal the impact of moisture changes on strength reduction or enhancement, helping to incorporate environmental factors into the prediction framework and achieve scientific correction of environmental humidity sensitivity. Finally, by combining the characteristic analysis results of the correlation between ambient humidity and prediction error changes and the degree of influence, a dynamic humidity compensation mechanism is introduced. This mechanism can adaptively adjust the prediction output according to real-time environmental data, significantly reducing the detection error caused by humidity fluctuations, enhancing the adaptability of the online strength detection operation of corrugated cardboard to actual environmental conditions, and improving the accuracy of the overall prediction results. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a flow chart of the steps of a method for testing the strength of corrugated paperboard for producing corrugated packaging boxes provided by the present invention; Figure 2 This is a flowchart of the steps of the method for obtaining the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed provided by the present invention; Figure 3 This is a partial schematic diagram of the changing relationship between pressure data and displacement data corresponding to the corrugated cardboard under normal production environment humidity provided by the present invention; Figure 4 It is a flowchart of the steps of the method for obtaining the characteristic deviation index of each environmental humidity to be analyzed provided by the present invention. DETAILED DESCRIPTION

[0018] To further illustrate the technical means and effectiveness of the present invention in achieving its intended objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effectiveness of a corrugated cardboard strength testing method for corrugated packaging production according to the present invention. In the following description, references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0019] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0020] The following describes in detail a method for detecting the strength of corrugated paperboard for producing corrugated packaging boxes provided by the present invention with reference to the accompanying drawings.

[0021] The main purpose of the present invention is to: when spot checks are carried out during online detection, if a prediction error is identified in the basic prediction model, the laboratory's strength prediction model is corrected in combination with the moisture content performance of corrugated cardboard under different environmental humidity conditions collected in the laboratory and the corresponding strength test results. That is, on the basis of the basic prediction model, compensation is made in combination with the environmental humidity, and the static model is upgraded to a dynamic model containing environmental variables, thereby improving the detection accuracy of the strength prediction model of the corrugated cardboard constructed based on laboratory data, and thereby improving the accuracy of online detection of the strength of the corrugated cardboard using the strength prediction model.

[0022] See also Figure 1 , which shows a flowchart of a method for testing the strength of corrugated cardboard for corrugated packaging box production according to an embodiment of the present invention, the method comprising the following steps: Step S100: obtaining the moisture content data of the corrugated paperboard under different ambient humidity, as well as the actual edge crush strength and the predicted edge crush strength.

[0023] The first step is to collect the moisture content and strength test results of corrugated cardboard under different ambient humidity in the laboratory.

[0024] (1) Setting different ambient humidity: Place several identical corrugated cardboards from the same batch in a constant temperature and humidity chamber to control the humidity. Use a temperature and humidity recorder (Testo 175-H1) to record the relative humidity in each box, expressed as a percentage. The relative humidity in each box is the ambient humidity of the corrugated cardboard.

[0025] (2) Collecting moisture content data: Use a near-infrared moisture meter (MoistTech MR3) to measure the moisture content of each piece of corrugated cardboard at each ambient humidity. The moisture content of each piece of corrugated cardboard is the moisture content data of the corrugated cardboard at each ambient humidity.

[0026] (3) Collecting actual edge compression strength: At each ambient humidity, use a compression strength tester to test the edge compression strength of the corrugated cardboard under different ambient humidity conditions, and simultaneously record the corresponding deformation displacement length of the corrugated cardboard when different pressures are applied to the corrugated cardboard. The edge compression strength obtained by the instrument under each ambient humidity condition is the actual edge compression strength of the corrugated cardboard, the applied pressure is the corresponding pressure data of the corrugated cardboard, and the deformation displacement length of the corrugated cardboard is the corresponding displacement data of the corrugated cardboard.

[0027] (4) Setting up a data control group: Using the same batch of corrugated cardboard to simulate normal production conditions, as a specific example, the conditions described in the "Standard Atmospheric Conditions for Handling and Testing Paper, Paperboard, and Pulp Samples" are used as normal ambient humidity. In this example, the normal ambient humidity is set to 50% relative humidity. Data collection and strength testing of the corrugated cardboard are performed under normal ambient humidity.

[0028] The second step is to construct a strength prediction model for corrugated cardboard based on the key parameters of the corrugated cardboard collected in the laboratory.

[0029] Key process and structural parameters related to corrugated cardboard strength are collected, such as fluting type, cardboard thickness (mm), base paper ring crush strength (RCT, N / m), fluting height (mm), fluting density (pieces / 100mm), glue application (g / m²), production line speed (m / min), and pressure (kPa). This is used to construct an online corrugated cardboard strength prediction model based on multi-source data fusion. Each collected parameter is used as model input, and a multivariate linear regression model is trained. The model outputs a predicted value for the edge crush strength of the corrugated cardboard, which is recorded as the predicted edge crush strength of the corrugated cardboard. This can be achieved by collecting a historical dataset containing each parameter and the actual edge crush strength corresponding to the corrugated cardboard. The least squares method is then used to solve the coefficients to minimize the sum of squared errors between the predicted and measured values, thereby achieving the purpose of model training.

[0030] It should be noted that the dimensional differences between different input parameters may affect the model's performance and require standardization, such as using the Z-score standardization method. Furthermore, the process of linear fitting using a multivariate linear regression model is well known and will not be further elaborated upon here. In other embodiments, implementers may also select other prediction models to predict the edge crush strength of corrugated cardboard based on specific implementation scenarios.

[0031] The third step is to collect data on the corrugated cardboard production process, including the actual edge compression strength of the corrugated cardboard sampled during online testing (real-time monitoring), as well as the key parameters of the corrugated cardboard, which are used to obtain the predicted edge compression strength of the corrugated cardboard during the online testing process.

[0032] Specifically, first, using machine vision technology, scanners such as line scan cameras are installed vertically along the production line to monitor each corrugated cardboard sheet in real time, including its flute type and thickness, which are key parameters used to indirectly infer its strength (these are also the input parameters for the strength prediction model constructed in the laboratory). Each parameter is then input into the trained strength prediction model to obtain the predicted edge crush strength of the corrugated cardboard. Furthermore, at regular intervals, corrugated cardboard sheets are drawn from the production line and their actual edge crush strength is monitored in real time using a compression strength tester. Furthermore, a temperature and humidity recorder (Testo 175-H1) is used at the production line exit to monitor the ambient humidity in real time. Finally, each time a cardboard sheet passes through the online inspection area, the system automatically acquires its parameters and calculates and displays the predicted edge crush strength in real time.

[0033] The fourth step is to pre-process the collected data, specifically removing abnormal values, filling in missing items, unifying data formats and dimensions, etc. This is a well-known technology in the field of data processing and will not be described in detail here.

[0034] It should be understood that, whether testing online (production line testing) or offline (laboratory testing), a corrugated cardboard sheet should correspond to an actual edge crush strength, a predicted edge crush strength, and a moisture content value at a given ambient humidity. This step mainly introduces the method for obtaining the ambient humidity, which includes the ambient humidity during the production process on the corrugated cardboard production line and the ambient humidity tested in the corrugated cardboard laboratory.

[0035] Step S200: obtaining a prediction error at each ambient humidity based on the difference between the actual edge crush strength and the predicted edge crush strength of the corrugated board at each ambient humidity during the corrugated board production process, and screening the ambient humidity based on the prediction error to obtain the ambient humidity to be analyzed.

[0036] The corrugated cardboard used in the production of corrugated packaging boxes is made of highly absorbent fiber materials. When the production workshop environment fluctuates (such as heavy rain), the cardboard is very susceptible to moisture absorption. When the moisture content is too high, the processed cardboard will become soft and weak, and prone to collapse after packaging, resulting in a decrease in compressive strength. Commonly used online strength prediction models for corrugated cardboard calculate strength values ​​based on key parameters of the corrugated cardboard (such as flute type and thickness). When the ambient humidity fluctuates, using this model to predict strength will produce errors, which will affect the production quality of corrugated packaging boxes.

[0037] Based on this, this example first measures the prediction error caused by the potential impact of ambient humidity during the online testing of corrugated cardboard by comparing the difference between the results of online strength testing of corrugated cardboard during production and the actual strength measurements taken at fixed intervals. Then, the ambient humidity with the largest error is screened, allowing the laboratory to promptly analyze the humidity impact on corrugated cardboard under the same ambient humidity.

[0038] Specifically, the absolute difference between the actual and predicted edge crush strength of the corrugated cardboard at each ambient humidity during the corrugated cardboard production process is used as the prediction error at each ambient humidity. The prediction error at each ambient humidity is normalized, and the ambient humidity corresponding to the normalized prediction error exceeding a preset error threshold is selected as the ambient humidity to be analyzed.

[0039] The normalization method can employ the maximum-minimum normalization method, a well-known technique that will not be further elaborated upon here. The error threshold can be set to 0.15, and implementers can adjust this value based on the specific implementation scenario. When the prediction error for the ambient humidity corresponding to the corrugated cardboard sampled during production exceeds the error threshold, it indicates that the corrugated cardboard is significantly affected by the ambient humidity at that particular humidity level, resulting in significant errors in the basic prediction model. The selected ambient humidity levels for analysis represent the ambient humidity conditions where the corrugated cardboard is most significantly affected by humidity during the online testing (production line testing).

[0040] It should be understood that in this embodiment, when there is a significant difference between the actual edge crush strength of the corrugated cardboard sampled online and the predicted edge crush strength (that is, when the prediction error corresponding to the sampled corrugated cardboard is greater than the error threshold), the humidity compensation mechanism is triggered to analyze the effect of ambient humidity on the strength of the corrugated cardboard under the same ambient humidity conditions in the laboratory. It should be noted that the ambient humidity in this step refers to the ambient humidity of the corrugated cardboard sampled during the production process.

[0041] Step S300: Analyze the influence of the moisture content data on the corrugated cardboard based on the relationship between the moisture content data of the corrugated cardboard and the ambient humidity under each ambient humidity to be analyzed, and combine the correlation between the pressure on the corrugated cardboard and the deformation of the corrugated cardboard to obtain the degree of influence of the corrugated cardboard under each ambient humidity to be analyzed.

[0042] Humidity affects the physical structure and mechanical response of corrugated cardboard, particularly under compression, where its stiffness and deformation characteristics vary with moisture content. During corrugated packaging production, the higher the ambient humidity, the greater the loss of compressive strength. Therefore, environmental factors must be considered to avoid quality issues during corrugated box production.

[0043] Based on this, a mapping relationship between ambient humidity, cardboard moisture content and strength attenuation was established through laboratory data, and the humidity factor was quantified as a compensation item that can be input into the model.

[0044] As a specific example, Figure 2 As shown, the method for obtaining the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed can be implemented by steps S301 to S304.

[0045] Step S301: obtaining different pressure data and corresponding displacement data of the corrugated paperboard under each environmental humidity to be analyzed, wherein the displacement data represents the deformation of the corrugated paperboard caused by the pressure.

[0046] In step S100, it has been recorded that different environmental humidity conditions are simulated in the laboratory, different pressures are applied to the corrugated cardboard under the same environmental humidity for each analyzed environmental condition, and the corresponding deformation displacement length of the corrugated cardboard is recorded, which are respectively recorded as the pressure data and displacement data corresponding to the corrugated cardboard under the environmental humidity to be analyzed.

[0047] Under normal production environment humidity, when the applied pressure does not exceed the elastic limit of the corrugated cardboard, as the pressure continues to increase, the displacement change of the corrugated cardboard under the corresponding pressure also increases. Figure 3 shown.

[0048] Step S302 , obtaining a characteristic deviation index for each ambient humidity to be analyzed based on the variation relationship between the pressure data and the displacement data corresponding to the corrugated cardboard under each ambient humidity to be analyzed and the deviation from the variation relationship under normal ambient humidity.

[0049] When the relative humidity in the environment of the corrugated cardboard increases, the corrugated cardboard absorbs more moisture, and the corresponding moisture content increases, and the strength of the corrugated cardboard decreases accordingly. However, when the corrugated cardboard is less affected by the environmental humidity, the displacement change trend of the corrugated cardboard under the same pressure should be relatively similar. The displacement change trend of different corrugated cardboards under pressure also reflects the strength change trend of the corrugated cardboard that can withstand the force, and thus reflects the current strength performance of the corrugated cardboard.

[0050] Based on this, by comparing the similarity of the displacement change trends of the corrugated cardboard under each environmental humidity to be analyzed with the corrugated cardboard under normal environmental humidity under different pressures, the degree to which the corresponding change trend of the corrugated cardboard under each environmental humidity to be analyzed deviates from the normal state is reflected.

[0051] As a specific example, Figure 4As shown, the method for obtaining the characteristic deviation index of each ambient humidity to be analyzed can be implemented by steps S3021 to S3024.

[0052] Step S3021: The pressure data corresponding to the corrugated cardboard under each to-be-analyzed environmental humidity are used to form a pressure data sequence under each to-be-analyzed environmental humidity.

[0053] It should be understood that the pressure data in the pressure data sequence are arranged in ascending order, and in other embodiments may also be arranged in descending order.

[0054] Step S3022: The displacement data corresponding to each corrugated cardboard under each to-be-analyzed environmental humidity are used to form a displacement data sequence under each to-be-analyzed environmental humidity.

[0055] It should be understood that the order of the displacement data in the displacement data sequence corresponds to the pressure data, that is, the displacement data of the corrugated cardboard exists due to the pressure data on the corrugated cardboard.

[0056] Step S3023: The Pearson correlation coefficient between the pressure data sequence and the displacement data sequence under each of the to-be-analyzed environmental humidity conditions is used as the characteristic correlation coefficient under each of the to-be-analyzed environmental humidity conditions.

[0057] The characteristic correlation coefficient reflects the correlation trend between the pressure data and displacement data of the corrugated cardboard under the corresponding environmental humidity to be analyzed, and characterizes the mechanical properties of the corrugated cardboard under the environmental humidity to be analyzed, that is, the correlation between the pressure and deformation of the corrugated cardboard when it is under compression.

[0058] Step S3024: Obtain the characteristic correlation coefficient corresponding to the normal ambient humidity, and use the absolute value of the difference between each ambient humidity to be analyzed and the characteristic correlation coefficient under the normal ambient humidity as the characteristic deviation index of each ambient humidity to be analyzed.

[0059] The method for obtaining the characteristic correlation coefficient under normal ambient humidity is the same as the method for obtaining the characteristic correlation coefficient under the ambient humidity to be analyzed. The characteristic correlation coefficient under normal ambient humidity represents the correlation trend between the pressure data and displacement data of the corrugated cardboard under normal conditions.

[0060] The characteristic deviation index for each humidity level to be analyzed reflects the degree of difference between the correlation trend corresponding to the corrugated cardboard at the humidity level to be analyzed and the correlation trend corresponding to the corrugated cardboard at normal humidity. A smaller characteristic deviation index for the humidity level to be analyzed indicates that the corrugated cardboard at the humidity level to be analyzed is less affected by humidity and less deviates from normal conditions. A larger characteristic deviation index for the humidity level to be analyzed indicates that the corrugated cardboard at the humidity level to be analyzed is more affected by humidity and more deviates from normal conditions. In other words, the characteristic deviation index for each humidity level to be analyzed represents the degree to which the mechanical properties of the corrugated cardboard at that humidity level deviate from normal conditions.

[0061] Step S303 , obtaining the fitted moisture content of the corrugated cardboard under each of the to-be-analyzed environmental humidity according to the relationship between the moisture content data of the corrugated cardboard under each of the to-be-analyzed environmental humidity and the environmental humidity.

[0062] As the relative humidity increases, corrugated cardboard absorbs more moisture, increasing its moisture content and subsequently decreasing its strength. By applying different humidity levels, as seen in historical production workshop data, to corrugated cardboard, and simulating the moisture changes experienced in actual production environments in the laboratory, we found that higher humidity levels can soften the cardboard.

[0063] Furthermore, there is a significant positive correlation between ambient humidity and the moisture content of corrugated cardboard. The essence of this is that corrugated cardboard, as a porous hygroscopic material, will adsorb and desorb water vapor in the surrounding air, thereby adjusting its own moisture state to achieve hygroscopic balance.

[0064] Based on this, the moisture content data of the corrugated cardboard under different ambient humidity conditions were analyzed, and a linear relationship between the ambient humidity of the corrugated cardboard and the corresponding moisture content data under different ambient humidity conditions was constructed.

[0065] Specifically, a linear fit is performed using the humidity of each environment to be analyzed as the horizontal axis and the moisture content data of the corrugated cardboard under each humidity to be analyzed as the vertical axis to obtain a humidity-moisture content fitting relationship. The least squares method can be used for data fitting, which will not be further described here.

[0066] In other embodiments, in order to more accurately measure the linear relationship between ambient humidity and the moisture content data of corrugated cardboard, the data set during data fitting can select all ambient humidity data collected in the laboratory and the moisture content data of corrugated cardboard under the corresponding ambient humidity for fitting.

[0067] Furthermore, in the humidity-moisture content fitting relationship, a fitted moisture content corresponding to the corrugated cardboard at the humidity to be analyzed is determined based on each humidity of the environment to be analyzed. It should be understood that by substituting the value of each humidity of the environment to be analyzed into the humidity-moisture content fitting relationship, the fitted moisture content corresponding to the corrugated cardboard at the humidity to be analyzed can be obtained.

[0068] In this step, the linear relationship between the ambient humidity and the moisture content data of the corrugated cardboard under the corresponding ambient humidity is fitted by laboratory data, so that in subsequent production, the corresponding moisture content data of the corrugated cardboard can be quickly calculated directly using the real-time monitored ambient humidity, which can take into account both real-time and economic efficiency to a certain extent.

[0069] Step S304 , according to the difference in characteristic deviation index between each ambient humidity to be analyzed and other ambient humidity, combined with the difference in corresponding fitted moisture content, the degree of influence of the corrugated cardboard under each ambient humidity to be analyzed is obtained.

[0070] The mechanical properties of corrugated cardboard are highly sensitive to moisture content. Increased moisture content weakens the bond between paper fibers, reducing cardboard strength. The nonlinear error in the model directly modeling the effect of ambient humidity on cardboard strength is large. Humidity directly affects cardboard moisture content. As the moisture content of corrugated cardboard increases, its internal fiber structure and interlayer connections gradually weaken, leading to a significant decrease in cardboard strength. This indirectly reveals the attenuation of cardboard strength due to ambient humidity. More specifically, moisture content has a significant negative correlation with the mechanical strength of corrugated cardboard. Mechanical properties such as compressive and flexural strength decrease significantly with increasing moisture content. Based on this, and considering the degree to which the mechanical properties of corrugated cardboard deviate from their normal state under the ambient humidity to be analyzed, the specific trends and magnitudes of the impact of moisture content on the mechanical strength of corrugated cardboard at each of the ambient humidity levels to be analyzed were analyzed.

[0071] The first step is to obtain the reference ambient humidity within the neighborhood of each ambient humidity to be analyzed, wherein the reference ambient humidity is arranged in a preset order.

[0072] Specifically, in order to avoid the randomness of the analysis results of a single ambient humidity, this embodiment considers adding the data change differences between other ambient humidity that are relatively close to the ambient humidity to be analyzed, and measures the change trend and magnitude of the influence of the moisture content data of the corrugated cardboard on the mechanical properties of the corrugated cardboard.

[0073] More specifically, all ambient humidity levels are arranged in ascending order, with each ambient humidity to be analyzed as the center, and a window of a preset length is defined as the neighborhood range of the corresponding ambient humidity to be analyzed. The preset length can be set to 5. All ambient humidity levels within the neighborhood range of each ambient humidity to be analyzed are recorded as reference ambient humidity. It should be understood that the reference ambient humidity also includes the ambient humidity to be analyzed.

[0074] In this embodiment, the reference ambient humidity is arranged in ascending order. In other embodiments, the reference ambient humidity can also be arranged in descending order. The purpose of setting the arrangement order is to more accurately measure the trend of the corresponding characteristic influence change with the change of ambient humidity.

[0075] In the second step, the absolute value of the difference between the characteristic deviation indicators under each two adjacent reference ambient humidity is used as the first characteristic difference under each two adjacent reference ambient humidity; the absolute value of the difference between the fitted moisture content under each two adjacent reference ambient humidity is used as the second characteristic difference under each two adjacent reference ambient humidity; based on the negative correlation coefficient between the first characteristic difference and the second characteristic difference, the characteristic attenuation degree under each two adjacent reference ambient humidity is determined; the average of all characteristic attenuation degrees within the neighborhood range of each ambient humidity to be analyzed is used as the degree of influence of the corrugated cardboard under each ambient humidity to be analyzed.

[0076] As a specific example, taking any environmental humidity to be analyzed as an example, the calculation formula for the degree of influence of the corrugated cardboard under the i-th environmental humidity to be analyzed can be expressed as:

[0077] in, It represents the degree of influence of the corrugated cardboard under the i-th environmental humidity to be analyzed, and N represents the total number of reference environmental humidity contained in the neighborhood of the i-th environmental humidity to be analyzed. It represents the characteristic deviation index of the nth reference ambient humidity within the neighborhood of the i-th ambient humidity to be analyzed, It represents the characteristic deviation index of the n+1th reference ambient humidity within the neighborhood of the i-th ambient humidity to be analyzed, represents the fitted moisture content of the nth reference ambient humidity within the neighborhood of the i-th ambient humidity to be analyzed, represents the fitted moisture content of the n+1th reference ambient humidity within the neighborhood of the i-th ambient humidity to be analyzed, This is a preset hyperparameter, and in this embodiment its value is 0.01, in order to prevent the denominator being 0 from affecting the calculation results.

[0078] The first characteristic difference reflects the difference in characteristic deviation index of the corresponding corrugated cardboard under two adjacent reference environmental humidity. The second characteristic difference reflects the difference in moisture content data of the corresponding corrugated cardboard under two adjacent reference environmental humidity.

[0079] Through the ratio This reflects the attenuation of mechanical properties and board strength caused by changes in moisture content data under continuous ambient humidity within the neighborhood of the i-th ambient humidity to be analyzed. The balance of attenuation corresponding to continuous ambient humidity within the neighborhood of the i-th ambient humidity to be analyzed measures the impact of ambient humidity on board strength. Furthermore, the degree of impact on corrugated board under the i-th ambient humidity to be analyzed represents the impact of ambient humidity on the strength of corrugated board under the i-th ambient humidity to be analyzed.

[0080] At this point, this step converts the impact of ambient humidity on cardboard strength into a quantifiable attenuation amplitude through the chain relationship between the ambient humidity, moisture content data, and attenuation amplitude corresponding to the corrugated cardboard. This provides an accurate data basis for subsequent dynamic humidity compensation, ultimately improving the accuracy of online strength detection.

[0081] Step S400: Based on the correlation between different ambient humidity and corresponding prediction errors and the degree of influence, the predicted edge compression strength of the corrugated cardboard under the ambient humidity to be analyzed is corrected, and the corrugated cardboard is subjected to online strength testing based on the corrected predicted edge compression strength.

[0082] The humidity of the corrugated packaging production environment directly determines the moisture content of the cardboard. Increased moisture content degrades the fiber structure and adhesive bond, significantly weakening the cardboard's compressive strength and structural stability. This is a key environmental factor affecting the box's compressive resistance. Furthermore, based on error trend analysis and experimental data, a dynamic compensation mechanism was established, enabling the model to automatically adjust its prediction output based on real-time humidity, effectively improving the accuracy, stability, and environmental adaptability of online strength testing.

[0083] Based on this, we first consider that when the weather in the production workshop changes suddenly and the ambient humidity gradually increases, the prediction error of the corrugated cardboard during online strength testing will gradually change with the ambient humidity. In order to analyze whether the cardboard strength prediction error is caused by humidity changes.

[0084] In the first step, based on the differences between different ambient humidity and the corresponding prediction errors, the correlation between the prediction error and ambient humidity is obtained, thereby reflecting the correlation between the change in cardboard strength and ambient humidity.

[0085] Specifically, each ambient humidity is arranged in ascending order to form an ambient humidity sequence, and the prediction error corresponding to each ambient humidity in the ambient humidity sequence constitutes a prediction error sequence; the negative correlation normalization coefficient of the DTW distance between the ambient humidity sequence and the prediction error sequence is calculated to obtain the degree of correlation between the prediction error and the ambient humidity.

[0086] As a specific example, the correlation between the prediction error and the ambient humidity can be expressed as follows: ,in represents the correlation between the prediction error and the ambient humidity, represents the ambient humidity sequence, represents the forecast error sequence, Represents the DTW distance between the ambient humidity series and the prediction error series, Represents an exponential function with the natural constant e as its base.

[0087] when The smaller the value of , the smaller the difference between the changing trend of ambient humidity and the changing trend of the prediction error of corrugated cardboard under the corresponding ambient humidity. This means that the changing trends of the two are closer, indicating a greater degree of correlation between the two. In this case, it is more likely that the change in ambient humidity affects the error in the corresponding prediction results of corrugated cardboard. In this case, the degree of ambient humidity compensation should be greater during online prediction.

[0088] It should be noted that in the process of measuring the correlation between the prediction error and the ambient humidity, this embodiment uses all possible values ​​of the ambient humidity in the laboratory data to better evaluate the differences and correlations between environmental changes and corresponding changes in the prediction result errors.

[0089] That is, when using a general strength prediction model for online detection of corrugated cardboard, the influence of the humidity in the production workshop is not taken into account. The strength of the cardboard decreases due to the increase in humidity, and the online predicted strength of the corrugated cardboard obtained by the model is too high. Therefore, during the online detection process, it is necessary to dynamically compensate for the influence of humidity on the strength of the cardboard under the conditions of the ambient humidity and correct the predicted edge pressure strength of the corrugated cardboard.

[0090] In the second step, the predicted edge compression strength of the corrugated cardboard under each environmental humidity to be analyzed is weighted using the correlation degree and the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed to obtain a strength adjustment degree; and the difference between the predicted edge compression strength of the corrugated cardboard under each environmental humidity to be analyzed and the strength adjustment degree is used as the corrected edge compression strength of the corrugated cardboard under each environmental humidity to be analyzed.

[0091] The method for obtaining the strength adjustment degree is specifically as follows: calculating the product of the normalized value of the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed, the correlation degree, and the predicted edge compression strength of the corrugated cardboard under the corresponding environmental humidity to be analyzed as the strength adjustment degree under each environmental humidity to be analyzed.

[0092] As a specific example, taking any ambient humidity to be analyzed as an example, the calculation formula for the corrected edge pressure strength of the i-th ambient humidity to be analyzed can be expressed as: ,in, represents the corrected edge pressure strength of the i-th environmental humidity to be analyzed, Indicates the strength adjustment degree of the corrugated cardboard under the i-th environmental humidity to be analyzed, represents the predicted edge compression strength of the corrugated cardboard under the i-th environmental humidity to be analyzed, represents the correlation between the prediction error and the ambient humidity, Indicates the degree of influence of the corrugated cardboard under the i-th environmental humidity to be analyzed, is the normalization function.

[0093] When the ambient humidity increases, the strength of the corrugated cardboard decreases relatively under the environmental conditions of the ambient humidity, and the predicted result value obtained using the basic prediction model is too high. Therefore, when adding humidity compensation, the degree to which the mechanical properties of the corrugated cardboard are affected under the corresponding ambient humidity is eliminated from the original predicted edge compression strength to correct the prediction error caused by the ambient humidity.

[0094] At this point, based on the output of the original strength prediction model, humidity compensation is performed by combining the correlation between the prediction error and the ambient humidity, and the degree to which the mechanical properties of the corrugated cardboard are affected by the attenuation of ambient humidity. The above formula calculation process is used to achieve real-time correction. In essence, it upgrades the static prediction model to a dynamic model that includes environmental variables, which can improve the accuracy, stability and environmental adaptability of online strength detection.

[0095] Finally, the corrugated cardboard is subjected to online strength testing based on the corrected predicted edge crush strength of the corrugated cardboard.

[0096] In this embodiment, the online strength testing process can be understood as a combined testing process using a basic strength prediction model and adaptive humidity compensation. Specifically, the online strength testing process can be described as follows: First, a multivariate linear regression model trained based on laboratory data is used as the basic strength prediction model to obtain the predicted edge crush strength of the corrugated cardboard under different ambient humidity levels. Then, when the online detection indicates a significant deviation in the predicted results for the corrugated cardboard under different ambient humidity levels, the humidity compensation mechanism is triggered (corresponding to step S200). Specifically, each time a cardboard passes through the online testing area, the system automatically acquires its parameters and calculates and displays the predicted edge crush strength in real time. Simultaneously, combined with online production environment information collection, the impact of humidity changes on strength prediction is dynamically compensated. The corrected predicted edge crush strength of the corrugated cardboard serves as the online strength testing result, thereby improving the accuracy and stability of corrugated cardboard strength testing results during the box production process.

[0097] It's important to note that during the laboratory model building process, the ambient humidity data testing range needs to cover as many humidity scenarios as possible for online testing. To ensure the model can adapt to environmental changes during long-term production, regular spot checks can be set up during online testing, with errors fed back to the laboratory to update model parameters and improve accuracy.

[0098] In summary, the present invention combines online strength detection with offline sampling detection, analyzes the influence of humidity-related parameters on the strength estimation of corrugated cardboard according to the changes in prediction errors, and performs dynamic humidity compensation. It can effectively correct the prediction deviation caused by fluctuations in ambient humidity and improve the model's adaptability to actual working conditions, thereby significantly improving the accuracy and stability of online strength detection of corrugated cardboard, ensuring the consistency of product quality and the intelligence level of the production process.

[0099] By comparing the online prediction values ​​with the actual sampling results, the system can identify the fluctuation trend and deviation law of the prediction error, which helps to discover the source of the model error in different environments or working conditions; clarifying the relationship between ambient humidity and cardboard moisture content, and establishing a model for the influence of moisture content on the compressive performance of cardboard, can reveal the impact of moisture changes on strength reduction or enhancement, help to incorporate environmental factors into the prediction framework, and achieve scientific correction of humidity sensitivity; introducing a dynamic humidity compensation mechanism, which can adaptively adjust the prediction output according to real-time environmental data, significantly reduce the detection error caused by humidity fluctuations, enhance the adaptability of the corrugated cardboard strength online detection system to actual working conditions, improve the overall prediction accuracy and intelligence level, and provide more stable and reliable technical support for corrugated cardboard quality control.

[0100] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for testing the strength of corrugated cardboard used in the production of corrugated packaging boxes, characterized in that: The method comprises the following steps: Obtain the moisture content data of corrugated cardboard under different ambient humidity, as well as the actual edge crush strength and predicted edge crush strength; According to the difference between the actual edge compression strength and the predicted edge compression strength of the corrugated board at each ambient humidity during the production process of the corrugated board, a prediction error at each ambient humidity is obtained, and the ambient humidity is screened based on the prediction error to obtain the ambient humidity to be analyzed; Based on the relationship between the moisture content data of the corrugated cardboard and the ambient humidity under each environmental humidity to be analyzed, combined with the correlation between the pressure on the corrugated cardboard and the deformation of the corrugated cardboard, the influence of the moisture content data on the corrugated cardboard is analyzed to obtain the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed; According to the correlation between different ambient humidity and corresponding prediction errors, combined with the degree of influence, the predicted edge compression strength of the corrugated cardboard under the ambient humidity to be analyzed is corrected, and the corrugated cardboard is subjected to online strength testing based on the corrected predicted edge compression strength of the corrugated cardboard.

2. A corrugated cardboard strength testing method for corrugated packaging box production according to claim 1, characterized in that: The method analyzes the influence of the moisture content data on the corrugated cardboard according to the relationship between the moisture content data of the corrugated cardboard and the ambient humidity under each ambient humidity to be analyzed, and combines the correlation between the pressure on the corrugated cardboard and the deformation of the corrugated cardboard to obtain the degree of influence of the corrugated cardboard under each ambient humidity to be analyzed, specifically including: Obtain different pressure data and corresponding displacement data of the corrugated cardboard under each environmental humidity to be analyzed, wherein the displacement data represents the deformation of the corrugated cardboard caused by the pressure; According to the variation relationship between the pressure data and displacement data corresponding to the corrugated cardboard under each environmental humidity to be analyzed and the deviation from the variation relationship under normal environmental humidity, a characteristic deviation index of each environmental humidity to be analyzed is obtained; According to the relationship between the moisture content data of the corrugated cardboard under each environmental humidity to be analyzed and the environmental humidity, the fitted moisture content of the corrugated cardboard under each environmental humidity to be analyzed is obtained; According to the difference in characteristic deviation index between each environmental humidity to be analyzed and other environmental humidity, combined with the difference in corresponding fitted moisture content, the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed is obtained.

3. A corrugated cardboard strength testing method for corrugated packaging box production according to claim 2, characterized in that: The characteristic deviation index of each environmental humidity to be analyzed is obtained based on the variation relationship between the pressure data and displacement data corresponding to the corrugated cardboard under each environmental humidity to be analyzed and the deviation from the variation relationship under normal environmental humidity, specifically including: The pressure data corresponding to the corrugated cardboard under each environmental humidity to be analyzed constitutes a pressure data sequence under each environmental humidity to be analyzed, the displacement data corresponding to the corrugated cardboard under each environmental humidity to be analyzed constitutes a displacement data sequence under each environmental humidity to be analyzed, and the Pearson correlation coefficient between the pressure data sequence and the displacement data sequence under each environmental humidity to be analyzed is used as the characteristic correlation coefficient under each environmental humidity to be analyzed; The characteristic correlation coefficient corresponding to the normal ambient humidity is obtained, and the absolute value of the difference between each ambient humidity to be analyzed and the characteristic correlation coefficient under the normal ambient humidity is used as the characteristic deviation index of each ambient humidity to be analyzed.

4. A corrugated cardboard strength testing method for corrugated packaging box production according to claim 2, characterized in that: The method of obtaining the fitted moisture content of the corrugated cardboard under each environmental humidity to be analyzed according to the relationship between the moisture content data of the corrugated cardboard under each environmental humidity to be analyzed and the environmental humidity specifically includes: The humidity of each environment to be analyzed is used as the horizontal axis, and the moisture content data of the corrugated cardboard under each environment to be analyzed is used as the vertical axis to perform linear fitting to obtain the humidity-moisture content fitting relationship; In the humidity-moisture content fitting relationship, the fitting moisture content corresponding to the corrugated cardboard under the humidity of the environment to be analyzed is determined based on the humidity of each environment to be analyzed.

5. The method for testing the strength of corrugated cardboard for corrugated packaging box production according to claim 2, characterized in that: The method of obtaining the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed according to the difference in characteristic deviation index between each environmental humidity to be analyzed and other environmental humidity, combined with the difference in corresponding fitted moisture content, specifically includes: Obtaining reference ambient humidity within the neighborhood of each ambient humidity to be analyzed, wherein the reference ambient humidity is arranged in a preset order; The absolute value of the difference between the characteristic deviation indexes under each two adjacent reference ambient humidity is used as the first characteristic difference under each two adjacent reference ambient humidity; the absolute value of the difference between the fitted water content under each two adjacent reference ambient humidity is used as the second characteristic difference under each two adjacent reference ambient humidity; Based on the negative correlation coefficient between the first characteristic difference and the second characteristic difference, the characteristic attenuation degree under each two adjacent reference ambient humidity is determined; and the average of all characteristic attenuation degrees within the neighborhood range of each ambient humidity to be analyzed is used as the degree of influence of the corrugated cardboard under each ambient humidity to be analyzed.

6. A corrugated cardboard strength testing method for corrugated packaging box production according to claim 1, characterized in that: According to the correlation between different ambient humidity and corresponding prediction error, and in combination with the degree of influence, the predicted edge compression strength of the corrugated cardboard under the ambient humidity to be analyzed is corrected, specifically including: According to the difference between different ambient humidity and corresponding prediction error, the correlation degree between prediction error and ambient humidity is obtained; Using the correlation degree and the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed, weighting the predicted edge compression strength of the corrugated cardboard under each environmental humidity to be analyzed to obtain a strength adjustment degree; The difference between the predicted edge compression strength of the corrugated cardboard under each environmental humidity to be analyzed and the strength adjustment degree is used as the corrected edge compression strength of the corrugated cardboard under each environmental humidity to be analyzed.

7. A corrugated cardboard strength testing method for corrugated packaging box production according to claim 6, characterized in that: The step of obtaining the correlation between the prediction error and the ambient humidity according to the difference between the different ambient humidity and the corresponding prediction error specifically includes: Arrange each ambient humidity in ascending order to form an ambient humidity sequence, and form a prediction error sequence with the prediction error corresponding to each ambient humidity in the ambient humidity sequence; The negative correlation normalization coefficient of the DTW distance between the ambient humidity series and the prediction error series is calculated to obtain the degree of correlation between the prediction error and the ambient humidity.

8. The method for testing the strength of corrugated cardboard for corrugated packaging box production according to claim 6, characterized in that: The predicted edge compression strength of the corrugated cardboard under each to-be-analyzed environmental humidity is weighted using the correlation degree and the degree of influence of the corrugated cardboard under each to-be-analyzed environmental humidity to obtain a strength adjustment degree, specifically including: The product of the normalized value of the degree of influence of the corrugated cardboard under each environmental humidity to be analyzed, the correlation degree, and the predicted edge compression strength of the corrugated cardboard under the corresponding environmental humidity to be analyzed is calculated as the strength adjustment degree under each environmental humidity to be analyzed.

9. The method for testing the strength of corrugated cardboard for corrugated packaging box production according to claim 1, characterized in that: The method of obtaining the prediction error at each ambient humidity according to the difference between the actual edge compression strength and the predicted edge compression strength of the corrugated board at each ambient humidity during the corrugated board production process specifically includes: The absolute value of the difference between the actual edge crush strength and the predicted edge crush strength of the corrugated board at each ambient humidity during the corrugated board production process is taken as the prediction error at each ambient humidity.

10. The method for testing the strength of corrugated cardboard used in the production of corrugated packaging boxes according to claim 1, characterized in that: The screening of the ambient humidity based on the prediction error to obtain the ambient humidity to be analyzed specifically includes: The prediction error at each ambient humidity during the corrugated cardboard production process is normalized, and the ambient humidity corresponding to the normalized prediction error being greater than a preset error threshold is used as the ambient humidity to be analyzed.

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