A circular knife machine for forming foam tape and its control method

Abstract

This invention relates to the field of plastic molding technology, specifically to a circular cutter machine for molding foam tape and its control method. Based on the characteristic that the pressure value of foam tape exhibits relatively chaotic nonlinear changes when the material deforms, this application first determines the stability of the temporal variation based on the temporal fluctuation of the conveyor belt pressure data, and then determines the trend variation volatility by combining the overall trend of the conveyor belt pressure data with the variation law of the pressure data. Thus, by combining the stability of the temporal variation and the trend variation volatility, a more accurate characterization of the degree of pressure value anomaly is achieved, and adaptive conveyor belt speed correction is performed based on the degree of pressure value anomaly, resulting in better final molding quality of the tape and improved foam tape molding effect.

Description

Technical Field

[0001] This invention relates to the field of plastic molding technology, specifically to a circular knife machine for molding foam tape and its control method. Background Technology

[0002] Foam tape refers to adhesive tape with a foam structure coated on a substrate, typically made from materials such as polyurethane, polyethylene, and polyvinyl chloride. This type of tape offers excellent cushioning, sealing, and shock absorption, and is commonly used for assembly and bonding in electronics, construction, automotive, and industrial fields. Its soft yet robust structure allows it to adapt to uneven surfaces and provides high-strength adhesion. In the foam tape manufacturing process, a rotary cutter is used for cutting, die-cutting, and slitting. After production, foam tape is usually in large rolls or flat sheets. The precise cutting by the rotary cutter processes it to specific dimensions and shapes, forming the required specifications. During the cutting process, the foam tape needs to be rewound at the output stage, and both the cutting and rewinding processes rely on conveyors.

[0003] Existing technologies typically use a fixed conveyor belt speed obtained a priori for foam tape forming. However, the most significant characteristic of foam tape is its elasticity and flexibility. When conveying it at a fixed speed, it is impossible to avoid idling due to the material properties of the foam tape itself. Idling can cause some winding during the unloading stage of winding, which in turn affects the final forming quality of the tape, resulting in poor foam tape forming effect. Summary of the Invention

[0004] This application provides a circular knife machine for forming foam tape and its control method. Based on the characteristic that the pressure value exhibits relatively chaotic nonlinear changes when the foam tape material deforms, the method first determines the stability of the temporal variation based on the temporal fluctuation of the conveyor belt pressure data, and then determines the trend variation volatility by combining the overall trend of the conveyor belt pressure data with the dimension of pressure data variation patterns. Thus, by combining the temporal variation stability and trend variation volatility, a more accurate characterization of the degree of pressure value anomaly is achieved. Furthermore, adaptive conveyor belt speed correction is performed based on the degree of pressure value anomaly. This solves the problem of idling caused by the material properties of the foam tape when conveying at a fixed conveyor speed. Idle idling leads to a certain degree of winding during the winding process at the discharge stage, resulting in better final tape forming quality and improved foam tape forming effect.

[0005] This application provides a control method for a circular knife machine for forming foam tape, including:

[0006] During the foam tape forming process, all conveyor belt pressure data at the contact points between the conveyor belt and the foam material were acquired in each sampling time period.

[0007] Based on the temporal variation and fluctuation of conveyor belt pressure data in each sampling time period, the temporal variation stability of each sampling time period is determined; based on the overall variation trend of conveyor belt pressure data in each sampling time period, the trend variation volatility of each sampling time period is determined.

[0008] Based on the stability of the time series changes and the volatility of the trend changes, the degree of pressure value anomaly in each sampling time period is determined; the conveyor belt speed is corrected based on the degree of pressure value anomaly, and the corrected conveyor belt speed for each sampling time period is determined; the circular knife machine for foam tape forming is controlled based on the corrected conveyor belt speed.

[0009] Furthermore, the process of obtaining the stability of the time-series changes includes:

[0010] In each sampling time period, the difference between the conveyor belt pressure data at each sampling moment and the conveyor belt pressure data at the previous sampling moment is taken as the instantaneous pressure deviation at each sampling moment;

[0011] The stability of the temporal variation in each sampling period is determined based on the overall magnitude of the instantaneous pressure deviation at all sampling times within each sampling period.

[0012] Furthermore, the process of determining the temporal stability of each sampling time period based on the overall magnitude of the instantaneous pressure deviation at all sampling moments within each sampling time period includes:

[0013] By performing a negative correlation mapping on the mean of the instantaneous pressure deviations at all sampling moments within each sampling time period, the temporal stability of the changes in each sampling time period can be obtained.

[0014] Furthermore, the process of obtaining the volatility of the trend change includes:

[0015] After arranging all the conveyor belt pressure data in each sampling time period in chronological order, curve fitting is performed to determine the fitted curve of the conveyor belt pressure data in each sampling time period.

[0016] In the conveyor belt pressure data fitting curve, the mean of the slope of the tangent line corresponding to all data points of all conveyor belt pressure data is used as the reference standard slope value.

[0017] Based on the overall deviation of the tangent slope of each conveyor belt pressure data point from the reference standard slope value, the trend variation fluctuation of each sampling time period is determined.

[0018] Furthermore, the process of determining the trend fluctuation of each sampling time period based on the overall deviation of the tangent slope of the data points corresponding to each conveyor belt pressure data from the reference standard slope value includes:

[0019] The difference between the tangent slope of the data point corresponding to each conveyor belt pressure data and the reference standard slope value is used as the slope standard deviation of each conveyor belt pressure data.

[0020] In each sampling period, the normalized value of the mean of the standard deviation of the slope of all conveyor belt pressure data is used as the trend change volatility for each sampling period.

[0021] Furthermore, the process of obtaining the degree of pressure abnormality includes:

[0022] The product of the negative correlation mapping value of the stability of the time series change and the preset first weight is used as the weighted change disorder; the product of the volatility of the trend change and the preset second weight is used as the weighted change volatility; the sum of the preset first weight and the preset second weight is 1, and both the preset first weight and the preset second weight are greater than 0;

[0023] The degree of pressure value anomaly in each sampling time period is determined based on the weighted variation disorder and the weighted variation volatility; both the weighted variation disorder and the weighted variation volatility are positively correlated with the degree of pressure value anomaly.

[0024] Furthermore, the process of determining the degree of pressure value anomaly for each sampling time period based on the weighted variation disorder and the weighted variation volatility includes:

[0025] The sum of the weighted variation disorder and the weighted variation volatility is normalized to determine the degree of pressure value anomaly in each sampling time period.

[0026] Furthermore, the process of obtaining the corrected conveyor belt speed includes:

[0027] When the abnormal pressure value is greater than the preset abnormal threshold, the product of the negative correlation mapping value of the abnormal pressure value and the preset prior conveyor belt speed is used as the corresponding corrected conveyor belt speed.

[0028] When the abnormality of the pressure value is less than or equal to the preset abnormality threshold, the preset prior conveyor belt speed is used as the corrected conveyor belt speed.

[0029] Furthermore, the process of controlling the circular knife machine for forming foam tape according to the modified conveyor belt speed includes:

[0030] After each sampling period ends, the conveyor belt speed is adjusted to the corresponding corrected conveyor belt speed and foam tape forming continues.

[0031] This application also proposes a circular cutter machine for forming foam tape, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of any one of the control methods for a circular cutter machine for forming foam tape.

[0032] This application has the following beneficial effects:

[0033] When the conveyor belt speed is inappropriate, the foam tape will typically deform due to its material properties. This deformation and subsequent idling can lead to abnormal pressure changes, necessitating adjustments to the conveyor belt speed. Firstly, conveyor belt pressure refers to the fundamental force supporting the conveyor belt's rotation. Changes in this pressure value are often accompanied by increases in the amount of material being conveyed or increases in cutting pressure. These factors represent normal pressure value fluctuations, characterized by a sudden increase in pressure reading followed by a period of stability. However, during material conveying, due to improper conveyor belt speed settings and the inherent elasticity and flexibility of the foam tape, deformation can occur, causing variations in the conveyor belt pressure value. These variations are not stable; deformation leads to a gradual increase in pressure, exhibiting a non-linear trend. Therefore, this application, based on this characteristic, first determines the stability of temporal changes in pressure data, and then determines the volatility of trend changes in pressure data patterns. This combined approach of temporal stability and trend volatility provides a more accurate characterization of the degree of pressure value anomalies. When the pressure value is significantly abnormal, it indicates a high degree of conveyor belt idling. Conveyor belt idling means that the material is not tightly adhered to the conveyor belt, resulting in uneven material movement and subsequent uneven winding. Because of the lack of tight adhesion, uneven material movement leads to a certain degree of deformation. Therefore, the greater the degree of pressure value abnormality, the higher the possibility of material winding at the outlet. Thus, it is necessary to adjust the speed promptly to suppress material winding caused by conveyor belt idling. Therefore, this application corrects the conveyor belt speed based on the abnormal pressure value and controls the circular knife machine for foam tape forming according to the corrected conveyor belt speed to suppress the influence of conveyor belt idling, resulting in better final tape forming quality and improved foam tape forming effect. Attached Figure Description

[0034] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 A flowchart illustrating a control method for a circular knife machine for forming foam tape, provided in one embodiment of the present invention;

[0036] Figure 2 This is a flowchart illustrating the trend change fluctuation of a control method for a circular knife machine for forming foam tape, provided in one embodiment of the present invention. Detailed Implementation

[0037] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a circular knife machine for forming foam tape and its control method according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment, and specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0038] Unless otherwise defined, 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 pertains.

[0039] The following description, in conjunction with the accompanying drawings, details the specific solution of a circular knife machine for forming foam tape and its control method provided by the present invention.

[0040] This application provides a control method for a circular knife machine used for forming foam tape. Please refer to [link to relevant documentation]. Figure 1 The diagram illustrates a flowchart of a control method for a circular knife machine for forming foam tape according to an embodiment of the present invention, comprising the following steps:

[0041] Step S101: During the foam tape forming process, acquire all conveyor belt pressure data at the contact position between the conveyor belt and the foam material in each sampling time period.

[0042] In one specific implementation of this invention, a resistance strain gauge pressure sensor is used to collect conveyor belt pressure data. The sensor is installed at the point where the conveyor belt contacts the foam material, secured with bolts or adhesive to ensure tight contact. The output signal of the resistance strain gauge pressure sensor is connected to the input of a control module, and the output of the control module is connected to the control terminal of the frequency converter. The control module can be a data processing chip such as a CPU or MCU, and can be wired via a data transmission line or wirelessly via Bluetooth, WiFi, or other wireless communication methods. After receiving the conveyor belt pressure data collected by the resistance strain gauge pressure sensor, the control module processes the data and outputs the corrected conveyor belt speed to the control terminal of the frequency converter for real-time control of the conveyor belt speed.

[0043] In one specific implementation of this invention, the length of each sampling time period is set to 1 minute, that is, the conveyor belt speed is corrected once every minute; and conveyor belt pressure data is collected once at each sampling moment in each sampling time period, the time interval between two adjacent sampling moments is set to 1 second, that is, the number of conveyor belt pressure data in each sampling time period is set to 60, which can be adjusted according to the specific implementation environment.

[0044] Step S102: Determine the stability of the temporal variation of the conveyor belt pressure data in each sampling time period based on the temporal variation fluctuation of the conveyor belt pressure data in each sampling time period; determine the trend variation volatility of the conveyor belt pressure data in each sampling time period based on the overall trend of the conveyor belt pressure data in each sampling time period.

[0045] When the conveyor belt speed is inappropriate, the foam tape will typically deform due to its material properties. This deformation and subsequent idling can lead to abnormal pressure changes, necessitating adjustments to the conveyor belt speed. Firstly, conveyor belt pressure refers to the fundamental force supporting the conveyor belt's rotation. Changes in this pressure value are often accompanied by increases in the amount of material being conveyed or increases in cutting pressure. These factors represent normal pressure value fluctuations, characterized by a sudden increase in pressure reading followed by a period of stability. However, during material conveying, due to improper conveyor belt speed settings and the inherent elasticity and flexibility of the foam tape, deformation can occur, causing variations in the conveyor belt pressure value. These variations are not stable; deformation leads to a gradual increase in pressure value with a certain non-linear trend. Therefore, based on this characteristic, this application first determines the stability of temporal changes in pressure data, then determines the volatility of trend changes in pressure data, and subsequently combines the stability of temporal changes and the volatility of trend changes to comprehensively characterize the degree of pressure data anomalies.

[0046] Preferably, in some possible implementations of the embodiments of the present invention, the process of obtaining the stability of time-series changes includes:

[0047] In each sampling time period, the difference between the conveyor belt pressure data at each sampling moment and the conveyor belt pressure data at the previous sampling moment is taken as the instantaneous pressure deviation at each sampling moment. The temporal stability of each sampling time period is determined based on the overall magnitude of the instantaneous pressure deviations at all sampling moments within each sampling time period. Preferably, in some possible implementations of this invention, the process of determining the temporal stability of each sampling time period based on the overall magnitude of the instantaneous pressure deviations at all sampling moments within each sampling time period includes: performing a negative correlation mapping on the mean of the instantaneous pressure deviations at all sampling moments within each sampling time period to obtain the temporal stability of each sampling time period.

[0048] Because normal pressure fluctuations share the characteristic of increasing pressure readings and then remaining constant for a certain period, pressure fluctuations under normal conditions are generally quite stable. Although there may be larger instantaneous pressure deviations at some sampling moments, the conveyor belt pressure data remains unchanged for the vast majority of sampling moments. This results in relatively small overall instantaneous pressure deviations under normal pressure fluctuation conditions, leading to greater stability in the time-series changes. Conversely, when the foam tape deforms, abnormal pressure changes occur. The corresponding pressure data gradually increases, resulting in larger overall instantaneous pressure deviations and less stability in the time-series changes. In other words, the lower the stability of the time-series changes, the more abnormal the corresponding pressure data.

[0049] In one specific implementation of this invention, the process of obtaining the stability of time-series changes is expressed by the following formula: W k For the temporal variation stability of the k-th sampling time period; C k F represents the number of sampling times in the k-th sampling time period; k，i F represents the conveyor belt pressure data at the i-th sampling time within the k-th sampling time period; k，(i-1) This represents the conveyor belt pressure data at the (i-1)th sampling time within the k-th sampling time period, which is also the conveyor belt pressure data at the sampling time preceding the ith sampling time within the k-th sampling time period; | represents the absolute value sign; |F k，i -F k，(i-1) | represents the instantaneous pressure deviation at the i-th sampling moment within the k-th sampling time period; exp() is an exponential function with the natural constant as its base. Implementers can use other negative correlation mapping methods, such as 1-Norm(), 1-tanh(), and the reciprocal, depending on the specific implementation environment. Among them, tanh() is the hyperbolic tangent function, which will not be elaborated further here.

[0050] Preferably, in some possible implementations of the embodiments of the present invention, the process of obtaining the volatility of trend changes includes: Please refer to Figure 2 The diagram illustrates a flowchart of the trend change fluctuation acquisition method for a control method of a circular knife machine for forming foam tape according to an embodiment of the present invention, including:

[0051] Step S201: Arrange all conveyor belt pressure data in each sampling time period in chronological order and then perform curve fitting to determine the fitted curve of the conveyor belt pressure data for each sampling time period.

[0052] By performing curve fitting on all conveyor belt pressure data within each sampling time period, the temporal changes in conveyor belt pressure data can be observed more clearly, thereby enabling a more accurate analysis of the overall trend of conveyor belt pressure data changes. In a specific implementation of this invention, a two-dimensional coordinate system is constructed with time on the horizontal axis and the magnitude of conveyor belt pressure data on the vertical axis. Data points corresponding to each sampling moment within each sampling time period are obtained in this two-dimensional coordinate system, and curve fitting is performed based on these data points to obtain the required conveyor belt pressure data fitting curve.

[0053] Step S202: In the fitting curve of the conveyor belt pressure data, the mean value of the slope of the tangent line corresponding to all data points of all conveyor belt pressure data is used as the reference standard slope value.

[0054] By calculating the mean of the tangent slope as the slope standard, the fluctuation characteristics of the overall pressure data trend can be analyzed based on the deviation of the tangent slope of each conveyor belt pressure data point from this slope standard.

[0055] Step S203: Determine the trend fluctuation of each sampling time period based on the overall deviation of the tangent slope of the data points corresponding to the pressure data of each conveyor belt relative to the reference standard slope value.

[0056] Preferably, in a specific implementation of this invention, the process of determining the trend fluctuation of each sampling time period based on the overall deviation of the tangent slope of the data points corresponding to each conveyor belt pressure data from the reference standard slope value includes:

[0057] The difference between the tangent slope of each data point corresponding to the conveyor belt pressure data and the reference standard slope value is taken as the slope standard deviation of each conveyor belt pressure data. In each sampling period, the normalized value of the mean of the slope standard deviations of all conveyor belt pressure data is taken as the trend change volatility of each sampling period.

[0058] Based on the normal characteristics of pressure value fluctuations, pressure changes are often accompanied by an increase in the amount of material to be conveyed on the conveyor belt and an increase in cutting pressure. The slope changes caused by the pressure changes are usually relatively stable. Furthermore, because the pressure value remains constant for a certain period after the increase, the distribution of the corresponding tangent slope is generally concentrated or stable. Therefore, under normal pressure value fluctuations, the overall deviation of the tangent slope of each data point corresponding to the conveyor belt pressure data from the reference standard slope value is small; that is, the overall standard deviation of each slope is small, and the corresponding trend fluctuation is also small. Conversely, when the foam tape deforms, i.e., when the pressure value becomes abnormal, the deformation causes the pressure value to exhibit a certain non-linear trend, making the overall pressure value fluctuation unstable. This is reflected in the data as a more dispersed distribution of the tangent slope of the overall conveyor belt pressure data points; that is, the overall deviation of the tangent slope of each data point corresponding to the conveyor belt pressure data from the reference standard slope value is large; the overall standard deviation of each slope is large, and the corresponding trend fluctuation is large. In other words, the greater the fluctuation, the more abnormal the conveyor belt pressure data.

[0059] In one specific implementation of this invention, the process of obtaining the volatility of trend changes includes: Among them, G k C represents the trend fluctuation of the k-th sampling time period; k Z represents the number of sampling times in the k-th sampling time period; k,i The slope of the tangent line corresponding to the data point of the conveyor belt pressure data at the i-th sampling time in the k-th sampling time period; It is the mean slope of the tangent line for all data points corresponding to all conveyor belt pressure data in the kth sampling time period, which is also the reference standard slope value corresponding to the kth sampling time period. represents the slope standard deviation of the conveyor belt pressure data at the i-th sampling time within the k-th sampling time period; || represents the absolute value sign; Norm() is the linear normalization function, and implementers can adjust the normalization method according to the specific implementation environment.

[0060] Step S103: Determine the degree of pressure value anomaly in each sampling time period based on the stability of time-series changes and the volatility of trend changes; correct the conveyor belt speed based on the degree of pressure value anomaly and determine the corrected conveyor belt speed for each sampling time period; control the circular knife machine for foam tape forming based on the corrected conveyor belt speed.

[0061] Both the stability of temporal variations and the volatility of trend variations can characterize abnormalities in conveyor belt pressure data to a certain extent. Therefore, the degree of pressure value anomaly is determined by comprehensively considering both the stability of temporal variations and the volatility of trend variations. A large degree of pressure value anomaly indicates a high degree of conveyor belt idling. Conveyor belt idling means that the material is not tightly attached to the conveyor belt, resulting in uneven material movement, which in turn leads to uneven winding. After not being tightly attached, uneven material movement causes a certain degree of deformation. Therefore, the greater the degree of pressure value anomaly, the higher the possibility of material winding at the outlet. Thus, it is necessary to adjust the speed in time to suppress material winding at the outlet caused by conveyor belt idling. Therefore, the conveyor belt speed is further corrected according to the degree of pressure value anomaly, thereby adaptively determining a more accurate corrected conveyor belt speed for each sampling time period. Then, the foam tape forming circular knife machine is controlled according to the corrected conveyor belt speed to suppress the influence of conveyor belt idling, resulting in better final tape forming quality and improved foam tape forming effect.

[0062] Preferably, in some possible implementations of the embodiments of the present invention, the process of obtaining the degree of pressure anomaly includes:

[0063] The product of the negative correlation mapping value of the time series change stability and the preset first weight is used as the weighted change disorder; the product of the trend change volatility and the preset second weight is used as the weighted change volatility; the sum of the preset first weight and the preset second weight is 1, and both the preset first weight and the preset second weight are greater than 0; the degree of pressure value anomaly in each sampling time period is determined according to the weighted change disorder and the weighted change volatility; in a specific implementation of this invention, the preset first weight is set to 0.4, and the preset second weight is set to 0.6; the preset first weight and the preset second weight are used to adjust the weight ratio of the time series change stability and the trend change volatility to the pressure value anomaly. This application sets the preset second weight to be larger, aiming to increase the influence of the overall trend change on the pressure value anomaly, and can be adjusted according to the specific implementation environment. Since the smaller the stability of time series changes and the greater the volatility of trend changes, the more abnormal the overall conveyor belt pressure data is, the weighted change disorder is obtained by multiplying the negative correlation mapping value of time series change stability with the preset first weight, and the weighted change volatility is obtained by multiplying the trend change volatility with the preset second weight. Therefore, both the weighted change disorder and the weighted change volatility are positively correlated with the degree of pressure value abnormality.

[0064] Preferably, in some possible implementations of the embodiments of the present invention, the process of determining the degree of anomaly of the pressure value for each sampling time period based on the weighted variation disorder and weighted variation volatility includes:

[0065] The sum of the weighted variation disorder and the weighted variation volatility is normalized to determine the degree of pressure value anomaly for each sampling time period. The normalization method limits the range of pressure value anomaly to 0 to 1, facilitating subsequent adjustment of the conveyor belt speed. In a specific implementation of this invention, the process of obtaining the pressure value anomaly is expressed by the formula: Q k = Norm(a×(1-W) k )+G k ×b); where Q k The stress value anomaly level for the k-th sampling time period; a is the preset first weight; b is the preset second weight; W k For the temporal stability of the k-th sampling time period; (1-W k ) represents the negative correlation mapping value of the temporal change stability of the k-th sampling time period, with a value range from 0 to 1;

[0066] a×(1-W k ) represents the weighted variation disorder of the k-th sampling time period; G k G represents the trend variation volatility during the k-th sampling time period; k ×b represents the weighted variation volatility of the k-th sampling time period; Norm() is a linear normalization function, and implementers can adjust the normalization method according to the specific implementation environment; it should be noted that, in addition to the normalized value of the sum, implementers can also calculate the degree of pressure abnormality through other methods based on the correlation, such as the normalized value of the product, etc., which will not be elaborated further here.

[0067] Preferably, in some possible implementations of the embodiments of the present invention, the process of obtaining the corrected conveyor belt speed includes:

[0068] When the pressure abnormality level exceeds a preset abnormality threshold, the product of the negative correlation mapping value of the pressure abnormality level and the preset prior conveyor belt speed is used as the corresponding corrected conveyor belt speed; when the pressure abnormality level is less than or equal to the preset abnormality threshold, the preset prior conveyor belt speed is used as the corrected conveyor belt speed. In a specific implementation of this invention, the preset abnormality threshold is set to 0.53, which can be adjusted according to the specific implementation environment. When the pressure abnormality level is less than or equal to the preset abnormality threshold, it indicates that the pressure abnormality level of the corresponding sampling time period is small, therefore it is considered that no pressure abnormality has occurred, so no adjustment operation is performed on the conveyor belt speed. Conversely, when the pressure abnormality level exceeds the preset abnormality threshold, it indicates that a pressure abnormality exists, so the conveyor belt speed needs to be adjusted. Pressure anomalies are usually caused by idling. Therefore, to reduce the impact of idling, the conveyor belt speed needs to be reduced according to the severity of the pressure anomaly. When the pressure anomaly exceeds a preset anomaly threshold, the corrected conveyor belt speed is determined by multiplying the negative correlation mapping value of the pressure anomaly severity with a preset prior conveyor belt speed. In other words, the greater the impact of idling and the greater the pressure anomaly, the smaller the conveyor belt speed should be, thus reducing the winding anomaly at the discharge port. In one specific implementation of this invention, the preset prior conveyor belt speed is set to three-quarters of the maximum conveyor belt speed, which can be adjusted according to the specific implementation environment.

[0069] In one specific implementation of this invention, the process of obtaining the corrected conveyor belt speed when the abnormal pressure value exceeds a preset abnormal threshold is expressed by the formula: V k = (1-Q) k )×V k ′ Among them, V k The corrected conveyor speed is defined as the speed at which the pressure value anomaly exceeds a preset anomaly threshold during the k-th sampling time period; Q k The stress level abnormality during the k-th sampling time period is represented by V, which is greater than a preset abnormality threshold. k ′ The preset prior conveyor belt speed.

[0070] Preferably, in some possible implementations of the embodiments of the present invention, the process of controlling the circular knife machine for foam tape forming according to the corrected conveyor belt speed includes: after each sampling time period, adjusting the conveyor belt speed to the corresponding corrected conveyor belt speed and continuing foam tape forming. That is, the conveyor belt speed correction for each sampling time period occurs after the sampling time period ends, so that the corrected conveyor belt speed becomes the conveyor belt speed for the next sampling time period. When the pressure value is abnormal, that is, when the degree of pressure value abnormality is greater than a preset abnormality threshold, the influence of idling is suppressed by reducing the conveyor belt speed, and when the corresponding degree of pressure value abnormality returns to normal after a period of time, the initial preset prior conveyor belt speed is returned.

[0071] In summary, this application, based on the characteristic of the relatively chaotic nonlinear change in pressure value when foam tape material undergoes deformation, firstly determines the stability of temporal variation based on the temporal fluctuation of conveyor belt pressure data in the dimension of pressure data temporal fluctuation, and secondly determines the trend change volatility based on the overall change trend of conveyor belt pressure data in the dimension of pressure data change pattern. Thus, by combining temporal variation stability and trend change volatility, a more accurate characterization of the degree of pressure value anomaly is achieved. Furthermore, adaptive conveyor belt speed correction is performed based on the degree of pressure value anomaly. This solves the problem of idling caused by the material of the foam tape itself when conveying at a fixed conveyor belt speed. Idling leads to a certain degree of winding during the unloading stage of winding, resulting in better final tape forming quality and improved foam tape forming effect.

[0072] This application also proposes a circular cutter machine for forming foam tape, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of any one of the control methods for a circular cutter machine for forming foam tape.

[0073] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0074] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A control method for a circular knife machine for forming foam tape, characterized in that, The method includes: During the foam tape forming process, all conveyor belt pressure data at the contact points between the conveyor belt and the foam material were acquired in each sampling time period. Based on the temporal variation and fluctuation of conveyor belt pressure data in each sampling time period, the temporal variation stability of each sampling time period is determined; based on the overall variation trend of conveyor belt pressure data in each sampling time period, the trend variation volatility of each sampling time period is determined. Based on the stability of the time series changes and the volatility of the trend changes, the degree of pressure value anomaly in each sampling time period is determined; the conveyor belt speed is corrected based on the degree of pressure value anomaly, and the corrected conveyor belt speed for each sampling time period is determined; the circular knife machine for foam tape forming is controlled based on the corrected conveyor belt speed.

2. The control method for a circular knife machine for forming foam tape according to claim 1, characterized in that, The process of obtaining the stability of the time series variation includes: In each sampling period, the difference between the conveyor belt pressure data at each sampling moment and the conveyor belt pressure data at the previous sampling moment is taken as the instantaneous pressure deviation at each sampling moment; The stability of the temporal variation in each sampling period is determined based on the overall magnitude of the instantaneous pressure deviation at all sampling times within each sampling period.

3. The control method for a circular knife machine for forming foam tape according to claim 2, characterized in that, The process of determining the stability of the temporal variation of each sampling time period based on the overall magnitude of the instantaneous pressure deviation at all sampling moments within each sampling time period includes: By performing a negative correlation mapping on the mean of the instantaneous pressure deviations at all sampling moments within each sampling time period, the temporal stability of the changes in each sampling time period can be obtained.

4. The control method for a circular knife machine for forming foam tape according to claim 1, characterized in that, The process for obtaining the volatility of the trend change includes: After arranging all the conveyor belt pressure data in each sampling time period in chronological order, curve fitting is performed to determine the fitting curve of the conveyor belt pressure data in each sampling time period. In the conveyor belt pressure data fitting curve, the mean of the slope of the tangent line corresponding to all data points of all conveyor belt pressure data is used as the reference standard slope value. Based on the overall deviation of the tangent slope of each conveyor belt pressure data point from the reference standard slope value, the trend variation fluctuation of each sampling time period is determined.

5. The control method for a circular knife machine for forming foam tape according to claim 4, characterized in that, The process of determining the trend fluctuation of each sampling time period based on the overall deviation of the tangent slope of the data points corresponding to the pressure data of each conveyor belt relative to the reference standard slope value includes: The difference between the tangent slope of the data point corresponding to each conveyor belt pressure data and the reference standard slope value is used as the slope standard deviation of each conveyor belt pressure data. In each sampling period, the normalized value of the mean of the standard deviation of the slope of all conveyor belt pressure data is used as the trend change volatility for each sampling period.

6. The control method for a circular knife machine for forming foam tape according to claim 1, characterized in that, The process of obtaining the degree of pressure abnormality includes: The product of the negative correlation mapping value of the stability of the time series change and the preset first weight is used as the weighted change disorder; the product of the volatility of the trend change and the preset second weight is used as the weighted change volatility; the sum of the preset first weight and the preset second weight is 1, and both the preset first weight and the preset second weight are greater than 0; The degree of pressure value anomaly in each sampling time period is determined based on the weighted variation disorder and the weighted variation volatility; both the weighted variation disorder and the weighted variation volatility are positively correlated with the degree of pressure value anomaly.

7. The control method for a circular knife machine for forming foam tape according to claim 6, characterized in that, The process of determining the degree of pressure value anomaly for each sampling time period based on the weighted variation disorder and the weighted variation volatility includes: The sum of the weighted variation disorder and the weighted variation volatility is normalized to determine the degree of pressure value anomaly in each sampling time period.

8. The control method for a circular knife machine for forming foam tape according to claim 1, characterized in that, The process of obtaining the corrected conveyor belt speed includes: When the abnormal pressure value is greater than the preset abnormal threshold, the product of the negative correlation mapping value of the abnormal pressure value and the preset prior conveyor belt speed is used as the corresponding corrected conveyor belt speed. When the abnormality of the pressure value is less than or equal to the preset abnormality threshold, the preset prior conveyor belt speed is used as the corrected conveyor belt speed.

9. The control method for a circular knife machine for forming foam tape according to claim 1, characterized in that, The process of controlling the circular knife machine for forming foam tape according to the modified conveyor belt speed includes: After each sampling period ends, the conveyor belt speed is adjusted to the corresponding corrected conveyor belt speed and foam tape forming continues.

10. A circular knife machine for forming foam tape, characterized in that, The device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, when the processor executes the computer program, it implements the steps of a control method for a circular knife machine for forming foam tape as described in any one of claims 1 to 9.

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