Packaging bag automatic film blowing and bag making linkage production control method and system

Abstract

The invention provides a packaging bag automatic film blowing and bag making linkage production control method and system, and relates to the technical field of linkage production control. An annular array type laser range finder is installed at an outlet of a film bubble cooling air ring of a packaging bag film blowing procedure; generating a time domain change curve of the contour of the cross section of the bubble; extracting frequency components and amplitude distribution of radial jitter of the film bubbles; when the frequency component is matched with the rotating frequency of the bag making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold value, an opening degree adjusting control signal is output to a proportional adjusting valve of the cooling air ring, and the opening degree of an airflow channel in the radial shaking direction on the cooling air ring is increased; and meanwhile, an air pressure adjusting signal is output to a pneumatic tensioning roller arranged between the film blowing traction roller and the bag making traction roller, and the back pressure of the pneumatic tensioning roller is reduced. According to the application, the dynamic interference of mechanical vibration on a film bubble cooling flow field can be isolated while the bag making traction continuity is kept.

Description

Technical Field

[0001] This application relates to the field of integrated production control technology, and more specifically, to a method and system for integrated production control of automated blown film blowing and bag making for packaging bags. Background Technology

[0002] Linked production control technology is a core supporting technology in the field of automated packaging bag production. It integrates independent processes such as blown film forming and bag making into an integrated collaborative production line. By uniformly scheduling production cycle and operating parameters, it achieves continuous and efficient operation. This technology effectively breaks through the efficiency bottleneck of traditional segmented production, reduces manual intervention and production losses, and improves the overall automation level and capacity of the production line. It is a key technological guarantee for promoting the development of packaging product production towards large-scale, high-quality and intelligent development.

[0003] In existing blown film and bag-making integrated production lines, the bag-making process often adopts an intermittent film pulling operation. The mechanical vibration generated by its periodic operation is transmitted in the reverse direction along the film body to the area of ​​the film bubble that has not yet been fully solidified in the blown film section. The cooling and forming of the film bubble depends on the steady-state annular airflow field constructed by the cooling air ring. The stability of this airflow field directly determines the uniformity of film thickness. However, mechanical vibration will disrupt the steady state of the airflow field, causing radial vibration of the film bubble, resulting in a decrease in film forming quality. Traditional control methods only adjust for a single process and cannot dynamically resolve the coupling interference between vibration and airflow field. Therefore, how to isolate the dynamic interference of mechanical vibration on the cooling flow field of the film bubble while maintaining the continuity of bag-making traction has become a difficult problem for the industry. Summary of the Invention

[0004] This application provides a method and system for automated production control of blown film and bag making for packaging bags, which can isolate the dynamic interference of mechanical vibration on the cooling flow field of the film bubble while maintaining the continuity of bag making traction.

[0005] In a first aspect, this application provides a method for automated production control of extruded film and bag making for packaging bags, the method comprising the following steps: A ring array laser rangefinder is installed at the outlet of the film bubble cooling air ring in the film blowing process of packaging bags. The radial distance signal of the membrane bubble output by the ring array laser rangefinder is continuously acquired to generate a time-domain variation curve of the membrane bubble cross-sectional profile; Perform a fast Fourier transform on the time-domain variation curve to extract the frequency components and amplitude distribution of the radial jitter of the membrane bubble; When the frequency component matches the rotation frequency of the bag-making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, an opening adjustment control signal is output to the proportional adjustment valve of the cooling air ring to increase the opening of the airflow channel in the radial vibration direction on the cooling air ring. At the same time, an air pressure adjustment signal is output to the pneumatic tensioning roller located between the blown film traction roller and the bag making traction roller to reduce the back pressure of the pneumatic tensioning roller.

[0006] In this embodiment, continuously acquiring the radial distance signal of the membrane bubble output by the ring array laser rangefinder to generate the time-domain variation curve of the membrane bubble cross-sectional profile specifically includes: At fixed time intervals, each ranging unit of the ring array laser rangefinder is synchronously triggered to perform signal acquisition, and the radial distance signal of the membrane bubble output by each ranging unit is obtained. Filtering is performed on each radial distance signal to remove outliers and obtain the standardized radial distance signal for each ranging unit. The standardized radial distance signals of each ranging unit at the same acquisition time are time-aligned according to the circumferential arrangement order to generate membrane bubble cross-sectional profile data at each acquisition time. The cross-sectional profile data of the membrane bubble at each acquisition time are continuously stitched together to generate the time-domain variation curve of the cross-sectional profile of the membrane bubble.

[0007] In this embodiment, performing a Fast Fourier Transform on the time-domain variation curve to extract the frequency components and amplitude distribution of the radial jitter of the membrane bubble specifically includes: From the time-domain variation curve, continuous time-domain data segments are extracted as time-domain sample data to be processed; According to the circumferential arrangement of the ranging units of the ring array laser rangefinder, the time-domain sample data is split into independent time-domain sequences for each circumferential orientation. Windowing is applied to each independent time-domain sequence to obtain preprocessed time-domain data adapted to the fast Fourier transform; Perform a Fast Fourier Transform on each preprocessed time-domain data to obtain frequency-domain data for each circumferential orientation; The frequency domain data of each circumferential direction are radially integrated to obtain the frequency components and amplitude distribution of the radial jitter of the membrane bubble.

[0008] In this embodiment, when the frequency component matches the rotation frequency of the bag-making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, an opening adjustment control signal is output to the proportional adjustment valve of the cooling air ring to increase the opening of the airflow channel in the radial vibration direction on the cooling air ring. Specifically, this includes: The real-time rotation frequency of the bag-making traction roller is collected synchronously, and the frequency component is compared with the real-time rotation frequency to determine whether the two match. When the frequency components match, the peak amplitude corresponding to the frequency component in the amplitude distribution is compared with a preset threshold to determine whether the peak amplitude exceeds the preset threshold. When the peak amplitude exceeds a preset threshold, the airflow channel in the radial vibration direction on the cooling fan ring is locked according to the circumferential orientation of the peak amplitude in the amplitude distribution. The opening increment of the airflow channel in the radial vibration direction on the cooling fan ring is determined based on the difference between the peak amplitude and the preset threshold. The proportional control signal for the cooling air ring is generated based on the opening adjustment increment, and the opening adjustment control signal is output to the proportional control valve to increase the opening of the airflow channel in the radial vibration direction on the cooling air ring.

[0009] In this embodiment, when the peak amplitude exceeds a preset threshold, locking the airflow channel in the radial vibration direction on the cooling fan ring based on the circumferential orientation of the peak amplitude in the amplitude distribution specifically includes: Establish a coaxial mapping relationship between the circumferential arrangement reference of the ranging unit of the ring array laser rangefinder and the circumferential arrangement reference of the cooling air ring airflow channel; Extract the circumferential arrangement position of the ranging unit corresponding to the peak amplitude in the amplitude distribution, and determine the circumferential arrangement reference interval of the circumferential arrangement position in the coaxial mapping relationship; Traverse the circumferential arrangement reference range of each airflow channel in the cooling air ring, and select the airflow channel that coincides with the circumferential arrangement reference range corresponding to the peak amplitude. Perform a layout benchmark overlap check on the selected airflow channels to determine the airflow channel with the highest overlap. The airflow channel with the highest overlap is locked as the airflow channel in the radial vibration direction on the cooling fan ring.

[0010] In this embodiment, determining the adjustment increment of the opening of the airflow channel in the radial jitter direction on the cooling fan ring based on the difference between the peak amplitude and the preset threshold specifically includes: Calculate the actual difference between the peak amplitude and the preset threshold, perform a grading process on the actual difference, and obtain the grading interval corresponding to the actual difference; Retrieve the pre-set mapping relationship between the difference grading interval and the opening adjustment increment, and determine the basic adjustment increment of the grading interval; Based on the current opening parameters of the airflow channel in the radial vibration direction on the cooling fan ring, the effective range of the basic adjustment increment is verified to determine the executable range of the basic adjustment increment. Within the executable range, the opening adjustment increment of the airflow channel in the radial vibration direction on the cooling fan ring is determined.

[0011] In this embodiment, the opening adjustment control signal of the proportional control valve for generating the cooling air ring is generated according to the opening adjustment increment, and the opening adjustment control signal is output to the proportional control valve. Increasing the opening of the airflow channel in the radial jitter direction on the cooling air ring specifically includes: Using the locked airflow channel as the main regulating channel, determine the adjacent airflow channels on both sides of the main regulating channel in the circumferential direction; The target opening of the main regulating channel and the target opening gradient of the adjacent airflow channels are determined based on the opening adjustment increment. The opening control signal of the proportional control valve of the cooling air ring is generated based on the target opening degree of the main control channel and the target opening degree gradient of the adjacent airflow channel. The opening adjustment control signal is synchronously output to the proportional control valve to drive the proportional control valve to perform the opening adjustment action; After the opening adjustment action is completed, the opening feedback signal of the proportional control valve is collected to confirm the execution status of the adjustment action.

[0012] In this embodiment, simultaneously outputting an air pressure adjustment signal to the pneumatic tensioning roller disposed between the blown film traction roller and the bag-making traction roller to reduce the back pressure of the pneumatic tensioning roller specifically includes: At the same time as the proportional control valve of the cooling air ring outputs the opening adjustment control signal, the back pressure adjustment action of the pneumatic tension roller is triggered. The back pressure adjustment range of the pneumatic tensioning roller is determined based on the amplitude distribution of the radial vibration of the membrane bubble. The pneumatic pressure adjustment signal of the pneumatic circuit of the pneumatic tensioning roller is generated according to the back pressure adjustment amplitude. The air pressure adjustment signal is output to the pneumatic control element of the pneumatic tensioning roller to adjust the air supply pressure of the pneumatic tensioning roller and reduce the back pressure of the pneumatic tensioning roller. After the back pressure adjustment is completed, the air pressure feedback signal of the pneumatic tensioning roller is collected to confirm the execution status of the adjustment action.

[0013] In this embodiment, outputting the air pressure adjustment signal to the pneumatic control element of the pneumatic tensioning roller to adjust the air supply pressure of the pneumatic tensioning roller and reduce the back pressure of the pneumatic tensioning roller specifically includes: The air pressure regulation signal is synchronously output to the pneumatic control elements of the air inlet and exhaust circuits of the pneumatic tension roller; The pneumatic control element of the intake circuit is adjusted downwards, and the pneumatic control element of the exhaust circuit is adjusted upwards. Real-time acquisition of internal pressure data in the air chamber of the pneumatic tensioning roller, and updating of the adjustment parameters of the pneumatic control components at fixed time intervals; Continue the adjustment operation until the internal pressure of the pneumatic tensioning roller reaches the target pressure value, then lock the current opening state of the pneumatic control element.

[0014] Secondly, this application provides an automated blown film and bag-making integrated production control system for packaging bags, used to execute an automated blown film and bag-making integrated production control method for packaging bags, the integrated production control system comprising: The equipment layout module is used to install a ring array laser rangefinder at the outlet of the film bubble cooling air ring in the film blowing process of packaging bags. The membrane bubble cross-sectional profile monitoring module is used to continuously acquire the radial distance signal of the membrane bubble output by the ring array laser rangefinder and generate the time-domain variation curve of the membrane bubble cross-sectional profile. The membrane bubble radial jitter feature extraction module is used to perform a fast Fourier transform on the time-domain variation curve to extract the frequency components and amplitude distribution of the membrane bubble radial jitter. The opening adjustment control module is used to output an opening adjustment control signal to the proportional adjustment valve of the cooling air ring when the frequency component matches the rotation frequency of the bag making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, thereby increasing the opening of the airflow channel in the radial vibration direction on the cooling air ring. The back pressure adjustment control module is used to simultaneously output an air pressure adjustment signal to the pneumatic tensioning roller located between the blown film traction roller and the bag making traction roller, thereby reducing the back pressure of the pneumatic tensioning roller.

[0015] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects: A ring-array laser rangefinder is installed at the outlet of the film bubble cooling air ring in the film blowing process of packaging bags; the radial distance signal of the film bubble output by the ring-array laser rangefinder is continuously collected to generate a time-domain variation curve of the cross-sectional profile of the film bubble; a fast Fourier transform is performed on the time-domain variation curve to extract the frequency components and amplitude distribution of the radial jitter of the film bubble; when the frequency components match the rotation frequency of the bag forming traction roller and the peak amplitude corresponding to the frequency components in the amplitude distribution exceeds a preset threshold, an opening adjustment control signal is output to the proportional adjustment valve of the cooling air ring to increase the opening of the airflow channel in the radial jitter direction on the cooling air ring; at the same time, an air pressure adjustment signal is output to the pneumatic tensioning roller set between the film blowing traction roller and the bag forming traction roller to reduce the back pressure of the pneumatic tensioning roller.

[0016] Therefore, in this application, when the frequency component matches the rotation frequency of the bag-making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, an opening adjustment control signal is output to the proportional adjustment valve of the cooling air ring to increase the opening of the airflow channel in the radial vibration direction on the cooling air ring; simultaneously, an air pressure adjustment signal is output to the pneumatic tensioning roller located between the blown film traction roller and the bag-making traction roller to reduce the back pressure of the pneumatic tensioning roller; wherein, firstly, by installing a ring array laser rangefinder at the outlet of the film bubble cooling air ring, the radial distance signal of the film bubble of each ranging unit is synchronously collected at fixed time intervals, and the signal is then filtered, time-aligned, and continuously spliced ​​to generate the time domain profile of the cross-sectional area of ​​the film bubble. The variable curve can capture the dynamic changes of the film bubble contour in real time and accurately, and the acquisition process does not contact the film body or interfere with the normal operation of film blowing and bag making traction, thus ensuring the continuity of bag making traction from the foundation. Secondly, by extracting time domain data segments, splitting independent time domain sequences, windowing processing, and fast Fourier transform, the time domain variable curve is processed and the frequency components and amplitude distribution of radial vibration of the film bubble are extracted. This can accurately match the rotation frequency of the bag making traction roller as the source of vibration, and at the same time lock the circumferential orientation and intensity of the vibration, solving the pain point of traditional control methods being unable to accurately locate vibration interference. Furthermore, when it is identified that the vibration frequency matches the rotation frequency of the bag making traction roller and the amplitude exceeds a preset threshold, synchronous acquisition is performed. The system compares the real-time rotation frequency of the bag traction roller, locks the airflow channel in the radial vibration direction, determines the opening adjustment increment based on the amplitude difference, and generates a control signal to directionally increase the opening of the airflow channel in the corresponding position of the cooling air ring. It also achieves directional reinforcement of the cooling airflow through gradient adjustment of the main adjustment channel and adjacent channels, as well as opening feedback verification. This rapidly repairs the steady-state annular airflow field damaged by vibration, resolves the interference of vibration on the membrane bubble cooling flow field, and avoids the instability of membrane bubble formation caused by global flow adjustment. Furthermore, while adjusting the cooling air ring, it simultaneously triggers the back pressure adjustment of the pneumatic tension roller, determines the adjustment amplitude based on vibration parameters, generates an air pressure adjustment signal, and adjusts the air supply pressure. This, combined with the coordinated adjustment of the inlet and outlet circuits, and pressure... Force feedback verification reduces the back pressure of the pneumatic tension roller, forming a flexible buffer without changing the bag-making traction rhythm. This effectively attenuates the reverse transmission of mechanical vibration at the bag-making end along the film, isolating it from the vibration propagation path and further ensuring the flow field stability in the uncured film bubble area. Finally, the entire control process adopts a synchronous linkage adjustment mode, with all adjustment actions dynamically adapted. This does not interrupt the continuous operation of the linkage production line or change the core operation mode of bag-making traction. It effectively solves the problem that traditional single-process adjustment cannot resolve the coupling interference between vibration and airflow field, while strictly maintaining the continuity of bag-making traction. It balances the efficiency of packaging bag production with the quality of film forming, promoting the development of linkage production lines towards high quality and intelligence.

[0017] In summary, the technical solution adopted in this application can achieve the goal of maintaining the continuity of bag making traction while isolating the dynamic interference of mechanical vibration on the cooling flow field of the membrane bubble. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application 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 for this embodiment of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an exemplary flowchart of an automated blown film and bag making integrated production control method for packaging bags provided in this application; Figure 2 This is a flowchart illustrating the process of locking the airflow channel provided in this application; Figure 3 This is a schematic diagram of the process for reducing the back pressure of the pneumatic tensioning roller provided in this application; Figure 4 This is a module structure diagram of an automated blown film and bag-making integrated production control system for packaging bags provided in this application. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] This application provides a method and system for automated production control of blown film and bag making in packaging bags. The core of this system is to install a ring-array laser rangefinder at the outlet of the cooling air ring in the blown film process. The system continuously collects the radial distance signal of the blown film from the ring-array laser rangefinder, generating a time-domain variation curve of the blown film cross-sectional profile. A fast Fourier transform is performed on the time-domain variation curve to extract the frequency components and amplitude distribution of the radial vibration of the blown film. When the frequency components match the rotation frequency of the bag-making traction roller and the peak amplitude corresponding to the frequency components in the amplitude distribution exceeds a preset threshold, an opening adjustment control signal is output to the proportional control valve of the cooling air ring to increase the opening of the airflow channel in the radial vibration direction on the cooling air ring. Simultaneously, an air pressure adjustment signal is output to the pneumatic tensioning roller located between the blown film traction roller and the bag-making traction roller to reduce the back pressure of the pneumatic tensioning roller.

[0022] Example 1: To better understand the above technical solution, the following will provide a detailed description of the technical solution in conjunction with the accompanying drawings and specific implementation methods. (Refer to...) Figure 1 As shown in the figure, this is an exemplary flowchart of a method for integrated production control of automated blown film blowing and bag making for packaging bags according to this embodiment of the present application. The integrated production control method includes the following steps: In step S1, a ring array laser rangefinder is installed at the outlet of the film bubble cooling air ring in the film blowing process of the packaging bag.

[0023] In practice, firstly, using a mounting bracket adapted to the blown film equipment, the ring array laser rangefinder is fixed on the outer circumferential side of the cooling air ring outlet of the film bubble, so that the ring array laser rangefinder is set around the film bubble; secondly, the overall position of the ring array laser rangefinder is adjusted so that the mounting axis of the ring array laser rangefinder is coaxial with the central axis of the film bubble; then, the fixing components of the mounting bracket are tightened to lock the installation posture of the ring array laser rangefinder, ensuring that the laser detection direction of each ranging unit is perpendicular to the outer wall of the film bubble, thus completing the installation operation of the ring array laser rangefinder.

[0024] It should be noted that the ring array laser rangefinder described in this application is a high-precision industrial-grade photoelectric measurement device adapted to the blown film production scenario of packaging bags. Based on the laser triangulation principle, it consists of an industrial-grade semiconductor laser, a focusing collimating lens group, a ring reflector, an industrial-grade area array camera, a narrowband filter, and an installation structure adapted to blown film equipment. Its core feature is that multiple ranging units are arranged in a uniform ring array, and the whole device can be set around the film bubble. The laser detection direction of each ranging unit is perpendicular to the outer wall of the film bubble, and the overall installation axis of the device can be kept coaxial with the central axis of the film bubble. During operation, the divergent laser beam emitted by the laser is focused by the focusing lens and projected onto the surface of the membrane bubble to form a laser spot. After being reflected 360 degrees by the ring mirror, the spot is imaged onto the camera image plane through the lens to form an imaging ring. The diameter of the imaging ring corresponds to the distance from the ranging unit to the outer wall of the membrane bubble, thereby realizing the synchronous, real-time, and high-precision acquisition of the radial distance of each point around the membrane bubble. This provides a reliable raw signal for the generation of the cross-sectional contour data of the membrane bubble, effectively overcoming the measurement error caused by the change in laser directionality and ensuring the accuracy and stability of the ranging.

[0025] In step S2, the radial distance signal of the membrane bubble output by the ring array laser rangefinder is continuously acquired to generate the time-domain variation curve of the membrane bubble cross-sectional profile.

[0026] In this embodiment, the continuous acquisition of the radial distance signal of the membrane bubble output by the ring array laser rangefinder, and the generation of the time-domain variation curve of the membrane bubble cross-sectional profile, can be achieved by the following steps: At fixed time intervals, each ranging unit of the ring array laser rangefinder is synchronously triggered to perform signal acquisition, and the radial distance signal of the membrane bubble output by each ranging unit is obtained. Filtering is performed on each radial distance signal to remove outliers and obtain the standardized radial distance signal for each ranging unit. The standardized radial distance signals of each ranging unit at the same acquisition time are time-aligned according to the circumferential arrangement order to generate membrane bubble cross-sectional profile data at each acquisition time. The cross-sectional profile data of the membrane bubble at each acquisition time are continuously stitched together to generate the time-domain variation curve of the cross-sectional profile of the membrane bubble.

[0027] It should be noted that, in this application, the radial distance signal of the membrane bubble represents the distance data between itself and the outer wall of the membrane bubble detected by each ranging unit in the ring array laser rangefinder; the membrane bubble cross-sectional profile data represents the profile data of the membrane bubble cross-section; and the time-domain variation curve represents the curve of the membrane bubble cross-sectional profile changing continuously over time.

[0028] In practice, firstly, at preset fixed time intervals, a synchronization trigger command is sent to all ranging units of the ring array laser rangefinder. Upon receiving the command, each ranging unit synchronously starts laser emission and signal reception operations, and the distance data output by each ranging unit is used as the radial distance signal of the membrane bubble. Secondly, a moving average filtering algorithm is used to process the radial distance signal of the membrane bubble output by each ranging unit point by point, identifying and eliminating abnormal values ​​such as sudden changes and jumps in the signal, and using the filtered distance data as the standardized radial distance signal of each ranging unit. Then, all ranging units at the same acquisition time are... The standardized radial distance signals of the unit are time-aligned according to the circumferential arrangement of each ranging unit of the ring array laser rangefinder. The set of all standardized radial distance signals after alignment is used as the membrane bubble cross-sectional profile data at the acquisition time. Finally, according to the order of signal acquisition time, the membrane bubble cross-sectional profile data corresponding to all acquisition times are sequentially spliced ​​to form a continuous data sequence. Then, a linear fitting algorithm is used to fit the continuous data sequence, and the continuous change curve obtained after fitting is used as the time-domain change curve of the membrane bubble cross-sectional profile.

[0029] In step S3, a fast Fourier transform is performed on the time-domain variation curve to extract the frequency components and amplitude distribution of the radial jitter of the membrane bubble.

[0030] In this embodiment, the frequency components and amplitude distribution of the radial jitter of the membrane bubble can be extracted by performing a fast Fourier transform on the time-domain variation curve using the following steps: From the time-domain variation curve, continuous time-domain data segments are extracted as time-domain sample data to be processed; According to the circumferential arrangement of the ranging units of the ring array laser rangefinder, the time-domain sample data is split into independent time-domain sequences for each circumferential orientation. Windowing is applied to each independent time-domain sequence to obtain preprocessed time-domain data adapted to the fast Fourier transform; Perform a Fast Fourier Transform on each preprocessed time-domain data to obtain frequency-domain data for each circumferential orientation; The frequency domain data of each circumferential direction are radially integrated to obtain the frequency components and amplitude distribution of the radial jitter of the membrane bubble.

[0031] It should be noted that the independent time-domain sequence described in this application is a time-domain data sequence of a single circumferential orientation; the frequency component of the radial jitter of the membrane bubble represents the frequency information reflecting the radial jitter of the membrane bubble; and the amplitude distribution of the radial jitter of the membrane bubble represents the amplitude distribution reflecting the radial jitter of the membrane bubble.

[0032] In specific implementation, firstly, based on the preset continuous data length requirement, the system traverses backward from the latest acquired data point of the time-domain variation curve, determining whether the data points are continuous and without abnormal missing data. If there is a data interruption, the segment is skipped, and the traversal continues forward until a complete data segment that meets the preset continuous length and has no missing data is selected. This selected continuous data segment is used as the time-domain sample data to be processed. Secondly, according to the circumferential arrangement order of each ranging unit of the circular array laser rangefinder, the intercepted time-domain sample data is divided into individual data sequences corresponding to each circumferential azimuth. Each individual data sequence obtained is used as an independent time-domain sequence for each circumferential azimuth. Next, the Hanning windowing algorithm is applied to each independent time-domain sequence to perform windowing processing. The Hanning window function smooths the transition between the two ends of the independent time-domain sequence, eliminating the spectral leakage problem caused by data abrupt changes. The obtained data is used as preprocessed time-domain data adapted to Fast Fourier Transform (FFT). Subsequently, FFT is applied to each preprocessed time-domain data to convert it into frequency and amplitude correlation data in the frequency domain. This correlation data is used as the frequency domain data for each circumferential azimuth. Finally, with the central axis of the bubble as the radial reference, the radial detection direction corresponding to each circumferential azimuth ranging unit is determined. All frequency points contained in the frequency domain data of all circumferential azimuths are extracted. For each frequency point, the amplitude corresponding to each circumferential azimuth is synthesized according to its radial detection direction to obtain the total radial amplitude corresponding to that frequency point. The information obtained after summing all frequency points is used as the frequency component of the bubble's radial jitter. The total radial amplitude corresponding to each frequency point is correlated with the corresponding circumferential azimuth to form amplitude data distributed along the bubble's radial direction, which is used as the amplitude distribution of the bubble's radial jitter.

[0033] In step S4, when the frequency component matches the rotation frequency of the bag-making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, an opening adjustment control signal is output to the proportional adjustment valve of the cooling air ring to increase the opening of the airflow channel in the radial shaking direction on the cooling air ring.

[0034] In this embodiment, when the frequency component matches the rotation frequency of the bag-making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, an opening adjustment control signal is output to the proportional adjustment valve of the cooling air ring. Increasing the opening of the airflow channel in the radial vibration direction on the cooling air ring can be achieved by the following steps: The real-time rotation frequency of the bag-making traction roller is collected synchronously, and the frequency component is compared with the real-time rotation frequency to determine whether the two match. When the frequency components match, the peak amplitude corresponding to the frequency component in the amplitude distribution is compared with a preset threshold to determine whether the peak amplitude exceeds the preset threshold. When the peak amplitude exceeds a preset threshold, the airflow channel in the radial vibration direction on the cooling fan ring is locked according to the circumferential orientation of the peak amplitude in the amplitude distribution. The opening increment of the airflow channel in the radial vibration direction on the cooling fan ring is determined based on the difference between the peak amplitude and the preset threshold. The proportional control signal for the cooling air ring is generated based on the opening adjustment increment, and the opening adjustment control signal is output to the proportional control valve to increase the opening of the airflow channel in the radial vibration direction on the cooling air ring.

[0035] In specific implementation, the real-time rotation frequency of the bag-making traction roller is synchronously acquired, and the frequency component is compared with the real-time rotation frequency to determine whether they match. When the frequency components match, the peak amplitude corresponding to the frequency component in the amplitude distribution is compared with a preset threshold to determine whether the peak amplitude exceeds the preset threshold. This can be achieved in the following way: First, the rotation signal of the bag-making traction roller is synchronously acquired through a speed encoder. The acquired rotation signal is processed using a pulse counting algorithm to count the number of rotations of the bag-making traction roller per unit time. The frequency of rotation is used as the real-time rotation frequency of the bag-making traction roller. At the same time, the frequency components of the radial vibration of the film bubble are obtained. The difference between the mean of all frequency values ​​in the frequency components and the real-time rotation frequency is calculated. If the difference is within the preset allowable range, the two are determined to match. If the difference exceeds the preset allowable range, the two are determined to not match. Secondly, when the frequency components are determined to match the real-time rotation frequency of the bag-making traction roller, the maximum amplitude value corresponding to the frequency components is extracted from the amplitude distribution of the radial vibration of the film bubble. The maximum amplitude value is used as the peak amplitude value. The peak amplitude value is directly compared with the preset threshold value to determine whether the peak amplitude value is greater than the preset threshold value.

[0036] Preferably, in this embodiment, when the peak amplitude exceeds a preset threshold, the airflow channel in the radial vibration direction of the cooling fan ring is locked according to the circumferential orientation of the peak amplitude in the amplitude distribution, with reference to... Figure 2 As shown in the figure, this is a schematic flowchart of locking the airflow channel in some embodiments of this application. In this embodiment, locking the airflow channel can be achieved by the following steps: In step S41, a coaxial mapping relationship is established between the circumferential arrangement reference of the ranging unit of the ring array laser rangefinder and the circumferential arrangement reference of the cooling air ring airflow channel. In step S42, the circumferential arrangement position of the ranging unit corresponding to the peak amplitude in the amplitude distribution is extracted, and the circumferential arrangement position is determined in the circumferential arrangement reference interval in the coaxial mapping relationship; In step S43, the circumferential arrangement reference interval of each airflow channel of the cooling air ring is traversed, and the airflow channel that coincides with the circumferential arrangement reference interval corresponding to the peak amplitude is selected. In step S44, the layout benchmark overlap of the selected airflow channels is checked to determine the airflow channel with the highest overlap. In step S45, the airflow channel with the highest overlap is locked as the airflow channel in the radial vibration direction on the cooling fan ring.

[0037] It should be noted that the coaxial mapping relationship described in this application refers to the correspondence between the circumferential arrangement reference of the ranging unit of the ring array laser rangefinder established with the central axis of the membrane bubble as a common reference and the circumferential arrangement reference of the airflow channel of the cooling air ring; the circumferential arrangement reference refers to the annular circumferential position reference standard divided with the central axis of the membrane bubble as the center; the circumferential arrangement reference interval refers to the annular circumferential position range covered by a single ranging unit or a single airflow channel under the circumferential arrangement reference; the arrangement reference overlap degree refers to the degree of overlap between the circumferential arrangement reference interval of the airflow channel of the cooling air ring and the circumferential arrangement reference interval corresponding to the peak amplitude; the airflow channel in the radial jitter direction refers to the channel on the cooling air ring that completely corresponds to the radial jitter direction of the membrane bubble and is used to adjust the cooling airflow.

[0038] In specific implementation, firstly, using the central axis of the membrane bubble as a common reference, the circumferential arrangement reference of each ranging unit of the ring array laser rangefinder is aligned and matched one by one with the circumferential arrangement reference of each airflow channel of the cooling air ring. The correspondence formed after alignment and matching is used as the coaxial mapping relationship between the circumferential arrangement reference of the ranging unit of the ring array laser rangefinder and the circumferential arrangement reference of the airflow channel of the cooling air ring. Secondly, from the amplitude distribution of the radial jitter of the membrane bubble, the circumferential arrangement position of the ranging unit corresponding to the peak amplitude is extracted. Using an interval matching algorithm, the circumferential arrangement position is substituted into the established coaxial mapping relationship to match the circumferential position range of the ring to which the position belongs. The matched circumferential position range is used as the circumferential arrangement of the circumferential arrangement position in the coaxial mapping relationship. The baseline interval is determined by the following steps: First, the circumferential baseline intervals corresponding to all airflow channels in the cooling ring are sequentially traversed. Airflow channels that overlap with the circumferential baseline interval corresponding to the peak amplitude are selected as candidate airflow channels. Then, an overlap ratio calculation algorithm is used to calculate the overlap ratio between the circumferential baseline interval of each candidate airflow channel and the circumferential baseline interval corresponding to the peak amplitude. The calculated overlap ratio is used as the baseline overlap ratio. The baseline overlap ratio values ​​of each candidate airflow channel are compared, and the candidate airflow channel with the highest overlap ratio is selected as the airflow channel with the highest overlap ratio. Finally, a locking operation is performed on the airflow channel with the highest overlap ratio, and the locked airflow channel is used as the airflow channel in the radial vibration direction on the cooling ring.

[0039] It should also be noted that the preset threshold in this application represents the critical amplitude for determining that the radial vibration of the membrane bubble exceeds the standard and triggering coordinated adjustment. Under normal operating conditions where membrane bubble production is stable and there are no molding defects, multiple sets of radial vibration amplitudes of the membrane bubble are collected, and the maximum value among them is used as the preset threshold.

[0040] In this embodiment, determining the adjustment increment of the airflow channel opening in the radial jitter direction on the cooling fan ring based on the difference between the peak amplitude and the preset threshold can be achieved through the following steps: Calculate the actual difference between the peak amplitude and the preset threshold, perform a grading process on the actual difference, and obtain the grading interval corresponding to the actual difference; Retrieve the pre-set mapping relationship between the difference grading interval and the opening adjustment increment, and determine the basic adjustment increment of the grading interval; Based on the current opening parameters of the airflow channel in the radial vibration direction on the cooling fan ring, the effective range of the basic adjustment increment is verified to determine the executable range of the basic adjustment increment. Within the executable range, the opening adjustment increment of the airflow channel in the radial vibration direction on the cooling fan ring is determined.

[0041] It should be noted that, in this application, the actual difference reflects the degree to which the radial vibration of the membrane bubble exceeds the allowable range; the grading process refers to the operation of dividing the actual difference into different intervals according to a preset grading standard; the grading interval refers to the numerical range to which the actual difference belongs after grading; the basic adjustment increment refers to the basic adjustment value of the opening of the cooling air ring airflow channel; the current opening parameter refers to the current actual opening data of the airflow channel in the radial vibration direction that has been locked on the cooling air ring; the effective interval verification refers to the operation of verifying the rationality of the basic adjustment increment in combination with the opening limit range of the airflow channel; the executable range refers to the numerical range of the basic adjustment increment that can be actually executed after the effective interval verification; the opening adjustment increment refers to the opening value that the airflow channel in the radial vibration direction on the cooling air ring needs to be increased, which is the adjustment parameter directly used to drive the proportional control valve.

[0042] It should also be noted that the mapping relationship between the difference grading interval and the opening adjustment increment described in this application represents the pre-set correlation between different grading intervals and the corresponding basic adjustment increment, which is used to match the appropriate adjustment amount according to the difference size; the difference between the peak amplitude and the preset threshold can be divided into three levels: slight, moderate and severe. The larger the difference, the larger the corresponding opening adjustment increment. The adjustment increment is controlled within the maximum and minimum opening of the cooling air ring airflow channel, and the correlation between the grading and the corresponding increment is used as a mapping relationship.

[0043] In specific implementation, firstly, the actual difference is obtained by subtracting the peak amplitude from a preset threshold. Then, a threshold grading algorithm is used to grade the actual difference. Multiple consecutive difference grading standards are preset, and the actual difference is compared with each grading standard one by one to classify the actual difference into the corresponding numerical range. This numerical range is used as the grading interval corresponding to the actual difference. Secondly, the pre-stored mapping relationship between the difference grading interval and the opening adjustment increment is retrieved. Based on the determined grading interval, the corresponding basic adjustment value is found in the mapping relationship, and the found basic adjustment value is used as the basic adjustment increment of the grading interval. Next, the current actual opening data of the airflow channel in the locked radial jitter direction on the cooling air ring is collected by the opening detection element. This data is used as the current opening parameter. A boundary verification algorithm is used in combination with the current opening parameter to perform effective interval verification on the basic adjustment increment, clarify the maximum and minimum opening limits of the cooling air ring airflow channel, and calculate the superposition of the basic adjustment increment and the current opening parameter. The system first removes adjustments that exceed the limit range by discarding those that do not. The basic adjustment increment range that meets the limit range requirements is then taken as the executable range of the basic adjustment increment. Finally, an optimal value selection algorithm for the executable range is used to determine a suitable adjustment value within the executable range. First, the upper and lower limits of the executable range are extracted. Then, the basic adjustment increment is compared with the upper and lower limits of the executable range. If the basic adjustment increment is within the executable range, it is directly used as the opening adjustment increment of the airflow channel in the radial jitter direction on the cooling fan ring. If the basic adjustment increment exceeds the upper limit of the executable range, the upper limit value of the executable range is selected as the opening adjustment increment. If the basic adjustment increment is lower than the lower limit of the executable range, the lower limit value of the executable range is selected as the opening adjustment increment. This ensures that the selected adjustment value meets both the equipment's opening limit requirements and the adjustment needs corresponding to the basic adjustment increment to the greatest extent possible. Finally, the selected adjustment value is used as the opening adjustment increment of the airflow channel in the radial jitter direction on the cooling fan ring.

[0044] In this embodiment, the opening adjustment control signal of the proportional control valve of the cooling air ring is generated according to the opening adjustment increment, and the opening adjustment control signal is output to the proportional control valve. The increase of the airflow channel opening in the radial jitter direction on the cooling air ring can be achieved by the following steps: Using the locked airflow channel as the main regulating channel, the adjacent airflow channels on both sides of the main regulating channel in the circumferential direction are determined; The target opening of the main regulating channel and the target opening gradient of the adjacent airflow channels are determined based on the opening adjustment increment. The opening control signal of the proportional control valve of the cooling air ring is generated based on the target opening degree of the main control channel and the target opening degree gradient of the adjacent airflow channel. The opening adjustment control signal is synchronously output to the proportional control valve to drive the proportional control valve to perform the opening adjustment action; After the opening adjustment action is completed, the opening feedback signal of the proportional control valve is collected to confirm the execution status of the adjustment action.

[0045] It should be noted that, in this application, the main regulating channel refers to the airflow channel on the pre-locked cooling air ring corresponding to the radial vibration direction of the film bubble; the adjacent airflow channel refers to the airflow channels that are adjacent to each other on both sides of the main regulating channel in the circumferential arrangement of the cooling air ring; the target opening degree refers to the opening degree value to be adjusted determined by the main regulating channel in combination with the opening degree adjustment increment; the target opening degree gradient refers to the gradient formed by the adjacent airflow channels with reference to the target opening degree of the main regulating channel; the opening degree adjustment control signal refers to the control signal that drives the proportional regulating valve of the cooling air ring to perform opening degree adjustment; and the opening degree feedback signal refers to the feedback signal after the proportional regulating valve is adjusted.

[0046] In specific implementation, firstly, the pre-locked radial jitter direction airflow channel is used as the main regulating channel. A clockwise neighborhood search algorithm is used to traverse the circumferential arrangement of all airflow channels in the cooling air ring, finding the airflow channels immediately adjacent to the main regulating channel on both sides of the circumference. These adjacent airflow channels are then used as the adjacent airflow channels on both sides of the main regulating channel. Secondly, the determined opening adjustment increment and the current opening parameter of the main regulating channel are retrieved. The current opening parameter of the main regulating channel is superimposed with the opening adjustment increment, and the superimposed value is used as the target opening of the main regulating channel. Then, a linear gradient decrease algorithm (e.g., an equal gradient linear decrease algorithm) is used to generate the opening change rule of the adjacent airflow channels according to the target opening of the main regulating channel. The gradient is formed by gradually and gently decreasing from the main regulating channel to both sides, and this gradient is used as the target opening gradient of the adjacent airflow channels. Next, a D / A conversion algorithm is used to convert the target opening of the main regulating channel and the target opening gradient of the adjacent airflow channels into analog electrical signals adapted to the proportional control valve. Then, a Manchester encoding algorithm is used to convert the analog signal into an analog electrical signal. The electrical signal is encoded according to the signal reception standard of the proportional control valve to ensure accurate signal identification. The encoded electrical signal is used as the opening control signal for the proportional control valve of the cooling air ring. Subsequently, a signal synchronization transmission algorithm is used to synchronously transmit the generated opening control signal to the corresponding proportional control valve through the control output module. This opening control signal serves as the drive command to drive the valve core of the proportional control valve to perform linear displacement adjustment, thereby executing the opening adjustment action and increasing the opening of the airflow channel in the radial jitter direction on the cooling air ring. Finally, the actual opening data of the proportional control valve is collected and used as the opening feedback signal of the proportional control valve. A difference comparison algorithm is then used to compare the actual opening data with the target opening of the main control channel and the target opening gradient of the adjacent airflow channel. During the comparison, a preset allowable deviation is used as the standard. The judgment result of whether the difference obtained after the comparison is within the preset allowable range is used as the execution status of the adjustment action, thereby confirming the execution status of the adjustment action.

[0047] In step S5, an air pressure adjustment signal is simultaneously output to the pneumatic tensioning roller located between the blown film traction roller and the bag making traction roller to reduce the back pressure of the pneumatic tensioning roller.

[0048] Preferably, in this embodiment, a pressure adjustment signal is simultaneously output to the pneumatic tensioning roller disposed between the blown film traction roller and the bag-making traction roller to reduce the back pressure of the pneumatic tensioning roller, as referenced. Figure 3 As shown in the figure, this is a schematic flowchart of reducing the back pressure of the pneumatic tensioning roller in some embodiments of this application. In this embodiment, reducing the back pressure of the pneumatic tensioning roller can be achieved by the following steps: In step S51, at the same time as outputting the opening adjustment control signal to the proportional regulating valve of the cooling air ring, the back pressure adjustment action of the pneumatic tensioning roller is triggered. In step S52, the back pressure adjustment amplitude of the pneumatic tensioning roller is determined based on the amplitude distribution of the radial vibration of the membrane bubble; In step S53, a pneumatic pressure adjustment signal for the pneumatic circuit of the pneumatic tensioning roller is generated according to the back pressure adjustment amplitude. In step S54, the air pressure adjustment signal is output to the pneumatic control element of the pneumatic tensioning roller to adjust the air supply pressure of the pneumatic tensioning roller and reduce the back pressure of the pneumatic tensioning roller. In step S55, after the back pressure adjustment action is completed, the air pressure feedback signal of the pneumatic tensioning roller is collected to confirm the execution status of the adjustment action.

[0049] It should be noted that, in this application, the back pressure adjustment action refers to the control action of the pneumatic tensioning roller adjusting its own back pressure, used to cooperate with cooling adjustment to suppress radial vibration of the film bubble; the back pressure adjustment range refers to the amount by which the back pressure of the pneumatic tensioning roller needs to be reduced; the air pressure adjustment signal refers to the electrical command that drives the pneumatic control element of the pneumatic tensioning roller to work, used to achieve precise adjustment of the back pressure; the pneumatic control element refers to the actuator in the pneumatic tensioning roller circuit used to adjust the air supply pressure, which can change the output air pressure in response to electrical signals; the air pressure feedback signal refers to the actual air supply pressure data fed back after the pneumatic tensioning roller completes the adjustment, used to verify the adjustment effect; the adjustment action execution status refers to the matching result between the actual back pressure of the pneumatic tensioning roller and the target adjustment value, used to determine whether the back pressure adjustment is completed.

[0050] In specific implementation, firstly, the output time of the cooling air ring proportional regulating valve opening adjustment control signal is used as the synchronization reference. At this time, the control process of the pneumatic tensioning roller is synchronously started, and this synchronous start operation is taken as the back pressure adjustment action of the pneumatic tensioning roller. Secondly, a proportional control algorithm is adopted, using the peak amplitude in the amplitude distribution of the membrane bubble radial jitter as the input parameter of the algorithm. The proportional coefficient of the proportional control algorithm is set according to the membrane bubble traction stability requirements and the rated back pressure adjustment range of the pneumatic tensioning roller. The input peak amplitude is processed by the proportional control algorithm, and the corresponding back pressure reduction value is output. The output value is taken as the back pressure adjustment amplitude of the pneumatic tensioning roller. Then, the back pressure adjustment amplitude is connected to the pneumatic tensioning roller. The control loop converts the back pressure adjustment amplitude into an electrical signal adapted to the pneumatic control element through the signal processing unit of the control loop. This converted electrical signal is used as the air pressure adjustment signal of the pneumatic circuit of the pneumatic tensioning roller. Subsequently, the air pressure adjustment signal is output to the pneumatic control element of the pneumatic tensioning roller to adjust the air supply pressure of the pneumatic tensioning roller and reduce the back pressure of the pneumatic tensioning roller. Finally, the actual air supply pressure of the pneumatic tensioning roller after adjustment is collected by the pressure detection element. The collected actual air supply pressure data is used as the air pressure feedback signal of the pneumatic tensioning roller. The air pressure feedback signal is directly compared with the target back pressure value. The matching result obtained from the comparison is used as the execution status of the adjustment action, thus confirming the execution status of the adjustment action.

[0051] In this embodiment, the air pressure adjustment signal is output to the pneumatic control element of the pneumatic tensioning roller to adjust the air supply pressure of the pneumatic tensioning roller and reduce the back pressure of the pneumatic tensioning roller. This can be achieved by the following steps: The air pressure regulation signal is synchronously output to the pneumatic control elements of the air inlet and exhaust circuits of the pneumatic tension roller; The pneumatic control element of the intake circuit is adjusted downwards, and the pneumatic control element of the exhaust circuit is adjusted upwards. Real-time acquisition of internal pressure data in the air chamber of the pneumatic tensioning roller, and updating of the adjustment parameters of the pneumatic control components at fixed time intervals; Continue the adjustment operation until the internal pressure of the pneumatic tensioning roller reaches the target pressure value, then lock the current opening state of the pneumatic control element.

[0052] It should be noted that, in this application, the pneumatic control element of the air inlet circuit refers to the actuator used to control the air intake of the pneumatic tensioning roller, which is responsible for adjusting the input of the air supply pressure; the pneumatic control element of the exhaust circuit refers to the actuator used to control the exhaust of the pneumatic tensioning roller, which is responsible for assisting in reducing the internal pressure of the air chamber; the opening reduction operation refers to the operation of reducing the air inlet diameter of the pneumatic control element of the air inlet circuit to reduce the air intake; the opening increase operation refers to the operation of increasing the air inlet diameter of the pneumatic control element of the exhaust circuit to increase the exhaust; the locked opening state indicates that the pneumatic control element maintains the current opening unchanged, ensuring that the air chamber pressure is stable at the target value, and cooperating with the cooling air ring adjustment to achieve the suppression of membrane bubble vibration.

[0053] In specific implementation, firstly, the air pressure adjustment signal is synchronously transmitted to the pneumatic control elements of the air inlet and exhaust circuits of the pneumatic tension roller, ensuring that the control elements of both circuits receive the signal simultaneously, avoiding a time difference in the adjustment action. This synchronous signal transmission and triggering of the pneumatic control element response is considered the completion state of the signal output. Secondly, after receiving the air pressure adjustment signal, the pneumatic control element of the air inlet circuit performs a downward adjustment operation through its own drive mechanism, reducing the air inlet diameter and decreasing the air intake rate. Simultaneously, the pneumatic control element of the exhaust circuit receives the air pressure adjustment signal and performs an upward adjustment operation through its own drive mechanism, increasing the exhaust diameter and increasing the exhaust rate. Through the coordinated operation of decreasing air intake and increasing exhaust volume, the initial downward adjustment of the air supply pressure of the pneumatic tension roller is achieved. Next, a real-time pressure acquisition module continuously collects the internal pressure data of the pneumatic tension roller's air chamber and transmits the collected real-time internal pressure data to the control unit, employing PID control... The algorithm takes real-time internal pressure data and target pressure value as input. The proportional, integral, and derivative coefficients of the PID control algorithm are set according to the pressure control accuracy and membrane traction stability requirements of the pneumatic tensioning roller. The PID control algorithm processes the input data and outputs real-time adjustment parameters. The output adjustment parameters are updated to the pneumatic control elements of the inlet and exhaust circuits at fixed time intervals to dynamically adjust the opening of the two circuit control elements and optimize the pressure regulation accuracy. Finally, the above opening adjustment operation is continuously executed. At the same time, the internal pressure data of the air chamber is compared with the target pressure value in real time through the pressure acquisition module. When the internal pressure of the pneumatic tensioning roller reaches the target pressure value, the control unit sends a locking command to the pneumatic control elements of the two circuits. After receiving the command, the pneumatic control elements stop the opening adjustment and lock the current opening state to ensure that the internal pressure of the air chamber is stable at the target pressure value, thus completing the operation of adjusting the air supply pressure and reducing the back pressure of the pneumatic tensioning roller.

[0054] Therefore, in this application, when the frequency component matches the rotation frequency of the bag-making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, an opening adjustment control signal is output to the proportional adjustment valve of the cooling air ring to increase the opening of the airflow channel in the radial vibration direction on the cooling air ring; simultaneously, an air pressure adjustment signal is output to the pneumatic tensioning roller located between the blown film traction roller and the bag-making traction roller to reduce the back pressure of the pneumatic tensioning roller; wherein, firstly, by installing a ring array laser rangefinder at the outlet of the film bubble cooling air ring, the radial distance signal of the film bubble of each ranging unit is synchronously collected at fixed time intervals, and the signal is then filtered, time-aligned, and continuously spliced ​​to generate the time domain profile of the cross-sectional area of ​​the film bubble. The variable curve can capture the dynamic changes of the film bubble contour in real time and accurately, and the acquisition process does not contact the film body or interfere with the normal operation of film blowing and bag making traction, thus ensuring the continuity of bag making traction from the foundation. Secondly, by extracting time domain data segments, splitting independent time domain sequences, windowing processing, and fast Fourier transform, the time domain variable curve is processed and the frequency components and amplitude distribution of radial vibration of the film bubble are extracted. This can accurately match the rotation frequency of the bag making traction roller as the source of vibration, and at the same time lock the circumferential orientation and intensity of the vibration, solving the pain point of traditional control methods being unable to accurately locate vibration interference. Furthermore, when it is identified that the vibration frequency matches the rotation frequency of the bag making traction roller and the amplitude exceeds a preset threshold, synchronous acquisition is performed. The system compares the real-time rotation frequency of the bag traction roller, locks the airflow channel in the radial vibration direction, determines the opening adjustment increment based on the amplitude difference, and generates a control signal to directionally increase the opening of the airflow channel in the corresponding position of the cooling air ring. It also achieves directional reinforcement of the cooling airflow through gradient adjustment of the main adjustment channel and adjacent channels, as well as opening feedback verification. This rapidly repairs the steady-state annular airflow field damaged by vibration, resolves the interference of vibration on the membrane bubble cooling flow field, and avoids the instability of membrane bubble formation caused by global flow adjustment. Furthermore, while adjusting the cooling air ring, it simultaneously triggers the back pressure adjustment of the pneumatic tension roller, determines the adjustment amplitude based on vibration parameters, generates an air pressure adjustment signal, and adjusts the air supply pressure. This, combined with the coordinated adjustment of the inlet and outlet circuits, and pressure... Force feedback verification reduces the back pressure of the pneumatic tension roller, forming a flexible buffer without changing the bag-making traction rhythm. This effectively attenuates the reverse transmission of mechanical vibration at the bag-making end along the film, isolating it from the vibration propagation path and further ensuring the flow field stability in the uncured film bubble area. Finally, the entire control process adopts a synchronous linkage adjustment mode, with all adjustment actions dynamically adapted. This does not interrupt the continuous operation of the linkage production line or change the core operation mode of bag-making traction. It effectively solves the problem that traditional single-process adjustment cannot resolve the coupling interference between vibration and airflow field, while strictly maintaining the continuity of bag-making traction. It balances the efficiency of packaging bag production with the quality of film forming, promoting the development of linkage production lines towards high quality and intelligence.

[0055] In summary, the technical solution adopted in this application can achieve the goal of maintaining the continuity of bag making traction while isolating the dynamic interference of mechanical vibration on the cooling flow field of the membrane bubble.

[0056] Example 2: This application provides an automated blown film and bag-making integrated production control system for packaging bags, referencing... Figure 4 As shown in the figure, this is a modular structure diagram of an automated blown film and bag-making integrated production control system for packaging bags according to this embodiment of the present application. The integrated production control system includes: Equipment layout module 100 is used to install a ring array laser rangefinder at the outlet of the film bubble cooling air ring in the film blowing process of packaging bags. The membrane bubble cross-sectional profile monitoring module 200 is used to continuously acquire the radial distance signal of the membrane bubble output by the ring array laser rangefinder and generate the time-domain variation curve of the membrane bubble cross-sectional profile. The membrane bubble radial jitter feature extraction module 300 is used to perform a fast Fourier transform on the time-domain variation curve to extract the frequency components and amplitude distribution of the membrane bubble radial jitter. The opening adjustment control module 400 is used to output an opening adjustment control signal to the proportional adjustment valve of the cooling air ring when the frequency component matches the rotation frequency of the bag making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, thereby increasing the opening of the airflow channel in the radial vibration direction on the cooling air ring. The back pressure adjustment control module 500 is used to simultaneously output an air pressure adjustment signal to the pneumatic tensioning roller located between the blown film traction roller and the bag making traction roller, thereby reducing the back pressure of the pneumatic tensioning roller.

[0057] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0058] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, including read-only memory (ROM), random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), one-time programmable read-only memory (OTPROM), electrically-Erasable Programmable Read-Only Memory (EEPROM), compactdisc read-only memory (CD-ROM) or other optical disc storage, disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data.

[0059] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

Claims

1. A method for automated production control of blown film and bag making for packaging bags, characterized in that, The coordinated production control method includes the following steps: A ring array laser rangefinder is installed at the outlet of the film bubble cooling air ring in the film blowing process of packaging bags. The radial distance signal of the membrane bubble output by the ring array laser rangefinder is continuously acquired to generate a time-domain variation curve of the membrane bubble cross-sectional profile; Perform a fast Fourier transform on the time-domain variation curve to extract the frequency components and amplitude distribution of the radial jitter of the membrane bubble; When the frequency component matches the rotation frequency of the bag-making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, an opening adjustment control signal is output to the proportional adjustment valve of the cooling air ring to increase the opening of the airflow channel in the radial vibration direction on the cooling air ring. At the same time, an air pressure adjustment signal is output to the pneumatic tensioning roller located between the blown film traction roller and the bag making traction roller to reduce the back pressure of the pneumatic tensioning roller.

2. The automated blown film and bag-making integrated production control method for packaging bags as described in claim 1, characterized in that, The process of continuously acquiring the radial distance signal of the membrane bubble output by the ring array laser rangefinder and generating the time-domain variation curve of the membrane bubble cross-sectional profile specifically includes: At fixed time intervals, each ranging unit of the ring array laser rangefinder is synchronously triggered to perform signal acquisition, and the radial distance signal of the membrane bubble output by each ranging unit is obtained. Filtering is performed on each radial distance signal to remove outliers and obtain the standardized radial distance signal for each ranging unit. The standardized radial distance signals of each ranging unit at the same acquisition time are time-aligned according to the circumferential arrangement order to generate membrane bubble cross-sectional profile data at each acquisition time. The cross-sectional profile data of the membrane bubble at each acquisition time are continuously stitched together to generate the time-domain variation curve of the cross-sectional profile of the membrane bubble.

3. The automated blown film and bag-making integrated production control method for packaging bags as described in claim 1, characterized in that, Performing a Fast Fourier Transform on the time-domain variation curve to extract the frequency components and amplitude distribution of the radial jitter of the membrane bubble specifically includes: From the time-domain variation curve, continuous time-domain data segments are extracted as time-domain sample data to be processed; According to the circumferential arrangement of the ranging units of the ring array laser rangefinder, the time-domain sample data is split into independent time-domain sequences for each circumferential orientation. Windowing is applied to each independent time-domain sequence to obtain preprocessed time-domain data adapted to the fast Fourier transform; Perform a Fast Fourier Transform on each preprocessed time-domain data to obtain frequency-domain data for each circumferential orientation; The frequency domain data of each circumferential direction are radially integrated to obtain the frequency components and amplitude distribution of the radial jitter of the membrane bubble.

4. The automated blown film and bag-making integrated production control method for packaging bags as described in claim 1, characterized in that, When the frequency component matches the rotation frequency of the bag-making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, an opening adjustment control signal is output to the proportional regulating valve of the cooling air ring to increase the opening of the airflow channel in the radial vibration direction on the cooling air ring. Specifically, this includes: The real-time rotation frequency of the bag-making traction roller is collected synchronously, and the frequency component is compared with the real-time rotation frequency to determine whether the two match. When the frequency components match, the peak amplitude corresponding to the frequency component in the amplitude distribution is compared with a preset threshold to determine whether the peak amplitude exceeds the preset threshold. When the peak amplitude exceeds a preset threshold, the airflow channel in the radial vibration direction on the cooling fan ring is locked according to the circumferential orientation of the peak amplitude in the amplitude distribution. The opening increment of the airflow channel in the radial vibration direction on the cooling fan ring is determined based on the difference between the peak amplitude and the preset threshold. The proportional control signal for the cooling air ring is generated based on the opening adjustment increment, and the opening adjustment control signal is output to the proportional control valve to increase the opening of the airflow channel in the radial vibration direction on the cooling air ring.

5. The automated blown film and bag-making integrated production control method for packaging bags as described in claim 4, characterized in that, When the peak amplitude exceeds a preset threshold, locking the airflow channel in the radial vibration direction on the cooling fan ring based on the circumferential orientation of the peak amplitude in the amplitude distribution specifically includes: Establish a coaxial mapping relationship between the circumferential arrangement reference of the ranging unit of the ring array laser rangefinder and the circumferential arrangement reference of the cooling air ring airflow channel; Extract the circumferential arrangement position of the ranging unit corresponding to the peak amplitude in the amplitude distribution, and determine the circumferential arrangement reference interval of the circumferential arrangement position in the coaxial mapping relationship; Traverse the circumferential arrangement reference range of each airflow channel in the cooling air ring, and select the airflow channel that coincides with the circumferential arrangement reference range corresponding to the peak amplitude. Perform a layout benchmark overlap check on the selected airflow channels to determine the airflow channel with the highest overlap. The airflow channel with the highest overlap is locked as the airflow channel in the radial vibration direction on the cooling fan ring.

6. The automated blown film and bag-making integrated production control method for packaging bags as described in claim 4, characterized in that, The specific steps for adjusting the opening increment of the airflow channel in the radial vibration direction on the cooling fan ring based on the difference between the peak amplitude and the preset threshold include: Calculate the actual difference between the peak amplitude and the preset threshold, perform a grading process on the actual difference, and obtain the grading interval corresponding to the actual difference; Retrieve the pre-set mapping relationship between the difference grading interval and the opening adjustment increment, and determine the basic adjustment increment of the grading interval; Based on the current opening parameters of the airflow channel in the radial vibration direction on the cooling fan ring, the effective range of the basic adjustment increment is verified to determine the executable range of the basic adjustment increment. Within the executable range, the opening adjustment increment of the airflow channel in the radial vibration direction on the cooling fan ring is determined.

7. The automated blown film and bag-making integrated production control method for packaging bags as described in claim 4, characterized in that, The proportional control signal for the cooling air ring is generated based on the opening adjustment increment. The opening adjustment control signal is then output to the proportional control valve. Specifically, increasing the opening of the airflow channel in the radial vibration direction on the cooling air ring includes: Using the locked airflow channel as the main regulating channel, determine the adjacent airflow channels on both sides of the main regulating channel in the circumferential direction; The target opening of the main regulating channel and the target opening gradient of the adjacent airflow channels are determined based on the opening adjustment increment. The opening control signal of the proportional control valve of the cooling air ring is generated based on the target opening degree of the main control channel and the target opening degree gradient of the adjacent airflow channel. The opening adjustment control signal is synchronously output to the proportional control valve to drive the proportional control valve to perform the opening adjustment action; After the opening adjustment action is completed, the opening feedback signal of the proportional control valve is collected to confirm the execution status of the adjustment action.

8. The automated blown film and bag-making integrated production control method for packaging bags as described in claim 1, characterized in that, Simultaneously, an air pressure adjustment signal is output to the pneumatic tensioning roller located between the blown film traction roller and the bag-making traction roller. Reducing the back pressure of the pneumatic tensioning roller specifically includes: At the same time as the proportional control valve of the cooling air ring outputs the opening adjustment control signal, the back pressure adjustment action of the pneumatic tension roller is triggered. The back pressure adjustment range of the pneumatic tensioning roller is determined based on the amplitude distribution of the radial vibration of the membrane bubble. The pneumatic pressure adjustment signal of the pneumatic circuit of the pneumatic tensioning roller is generated according to the back pressure adjustment amplitude. The air pressure adjustment signal is output to the pneumatic control element of the pneumatic tensioning roller to adjust the air supply pressure of the pneumatic tensioning roller and reduce the back pressure of the pneumatic tensioning roller. After the back pressure adjustment is completed, the air pressure feedback signal of the pneumatic tensioning roller is collected to confirm the execution status of the adjustment action.

9. The automated blown film and bag-making integrated production control method for packaging bags as described in claim 8, characterized in that, The air pressure regulation signal is output to the pneumatic control element of the pneumatic tensioning roller to adjust the air supply pressure of the pneumatic tensioning roller and reduce the back pressure of the pneumatic tensioning roller. Specifically, this includes: The air pressure regulation signal is synchronously output to the pneumatic control elements of the air inlet and exhaust circuits of the pneumatic tension roller; The pneumatic control element of the intake circuit is adjusted downwards, and the pneumatic control element of the exhaust circuit is adjusted upwards. Real-time acquisition of internal pressure data in the air chamber of the pneumatic tensioning roller, and updating of the adjustment parameters of the pneumatic control components at fixed time intervals; Continue the adjustment operation until the internal pressure of the pneumatic tensioning roller reaches the target pressure value, then lock the current opening state of the pneumatic control element.

10. An automated blown film and bag-making integrated production control system for packaging bags, used to execute the automated blown film and bag-making integrated production control method for packaging bags as described in any one of claims 1 to 9, characterized in that, The coordinated production control system includes: The equipment layout module is used to install a ring array laser rangefinder at the outlet of the film bubble cooling air ring in the film blowing process of packaging bags. The membrane bubble cross-sectional profile monitoring module is used to continuously acquire the radial distance signal of the membrane bubble output by the ring array laser rangefinder and generate the time-domain variation curve of the membrane bubble cross-sectional profile. The membrane bubble radial jitter feature extraction module is used to perform a fast Fourier transform on the time-domain variation curve to extract the frequency components and amplitude distribution of the membrane bubble radial jitter. The opening adjustment control module is used to output an opening adjustment control signal to the proportional adjustment valve of the cooling air ring when the frequency component matches the rotation frequency of the bag making traction roller and the peak amplitude corresponding to the frequency component in the amplitude distribution exceeds a preset threshold, thereby increasing the opening of the airflow channel in the radial vibration direction on the cooling air ring. The back pressure adjustment control module is used to simultaneously output an air pressure adjustment signal to the pneumatic tensioning roller located between the blown film traction roller and the bag making traction roller, thereby reducing the back pressure of the pneumatic tensioning roller.

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