Image recognition and space-time registration roll change control method and system and storage medium

Abstract

The present application relates to the technical field of automatic control of cigarette packaging equipment, in particular to a trademark paper roll changing control method and system based on end face image recognition and space-time registration and a storage medium, comprising: collecting paper roll end face image data and multi-channel asynchronous detection signals in real time; obtaining paper roll residual length and residual available time; based on the instantaneous conveying speed of the trademark paper obtained by the conveying end encoder, establishing a paper web conveying position coordinate axis, dynamically compensating the multi-channel asynchronous detection signals, and uniformly mapping the asynchronous signals to the same physical position; calculating the physical position deviation of each channel signal after mapping, and determining that the position consistency condition is met when the maximum deviation is less than a preset threshold; triggering roll changing execution when the residual available time reaches a preset preparation duration and the position consistency condition is met. The present application dynamically compensates and judges the consistency of multi-channel asynchronous signals by establishing a unified position coordinate axis, eliminates spatial deviation, and improves roll changing precision and running stability.

Description

Technical Field

[0001] This invention relates to the field of automated control technology for cigarette packaging equipment, specifically to a method, system, and storage medium for label paper changing control based on end-face image recognition and spatiotemporal registration. Background Technology

[0002] In cigarette packaging production lines, the high-speed continuous conveying and automatic roll changing of roll materials such as label paper and sealing paper are core processes that ensure the overall machine capacity and appearance quality. With packaging equipment operating speeds exceeding 800 packs per minute, coordinated control of multiple detection signals and precise alignment of roll changing points have become common technical challenges in the industry. Existing automatic roll changing control schemes mostly rely on time sequence for synchronization, using single-sensor threshold judgment or fixed delay compensation to trigger actions. Under high-speed conditions, it is difficult to eliminate positional deviations caused by the inherent delay of detection signals, leading to frequent problems such as misalignment, wrinkling, and paper breakage.

[0003] In the existing technology, patent CN216375336U, "Seal Paper Changing Device for Packaging Machines," discloses an automatic changing structure for alternating dual-roll feeding. It uses position sensors and a drive motor to switch paper rolls, and the overall control logic is designed around the timing of mechanical actions. A unified timestamp coordinates the operation of mechanisms such as the turntable, clamping, and cutting, achieving an automated process where the old roll is used up and a new roll is inserted. However, this solution only focuses on the timing synchronization of mechanical actions, without spatial position calibration for multiple detection signals or considering the spatial offset caused by inherent time delays during signal acquisition and algorithm calculation. This results in insufficient stability of splicing accuracy during high-speed operation.

[0004] Another patent, CN109969833A, titled "Automatic Roll Changing and Splicing Device for Cigarette Packaging Machines When Small Packet Paper is Depleted," uses a combination of electromagnetic brakes, logic-encoded toothed discs, and sensors to detect the remaining amount of paper rolls. This, combined with a programmable controller, triggers automatic roll changing and is a widely used roll changing solution in the tobacco packaging industry. However, its core control method relies on a single detection signal plus a fixed delay parameter to complete the action connection. It only performs independent delay compensation for a single signal, lacks a unified spatial position reference system, and lacks a position correlation verification mechanism between multiple detection signals. This makes it susceptible to control inaccuracies due to equipment acceleration / deceleration, paper web slippage, and load fluctuations.

[0005] In addition, the original label paper changing systems of mainstream FOCKE, PROTOS, and GDX2 series packaging machines in the industry generally use the traditional control mode of diameter detection and preset delay. During equipment operation, functional modules such as image detection, ultrasonic detection, and color difference detection have inherent delays of varying durations due to hardware sampling cycles and algorithm processing times. Under high-speed label paper conveying (linear speed ≥3m / s), the time deviation between signals will directly translate into physical spatial offset on the paper web path, causing the actual detection points corresponding to different detection signals to be misaligned. Existing technologies generally suffer from three key defects: First, the synchronization reference is unreasonable, using the time axis as the synchronization reference without establishing a unified paper web position coordinate axis across the entire domain using the encoder. This results in a lack of a unified reference standard for multiple detection signals, amplifying spatial offsets under high-speed conditions. Second, the compensation mechanism is simplistic, only performing independent time delay compensation for a single signal without conducting joint spatial mapping and deviation comparison for multiple signals, making cross-verification impossible and leading to misalignment of the decision reference. Third, the fault tolerance capability is insufficient: the control logic is mostly based on simple logical judgments, lacking fault tolerance and re-verification mechanisms after position deviations exceed limits, making it prone to faults such as cutting offsets, splicing wrinkles, and paper breaks when operating conditions fluctuate.

[0006] In summary, existing technologies, due to their reliance on time synchronization, lack of spatial reference, and lack of registration of multiple signals, cannot solve the core problems of signal delay-spatial offset conversion and misalignment of decision reference in high-speed label paper roll changing scenarios. This results in low roll changing accuracy, high failure rate, and large material loss. There is an urgent need for a multi-channel signal registration and roll changing control scheme based on spatial position consistency. Summary of the Invention

[0007] The purpose of this invention is to provide a label paper roll changing control method, system, and storage medium based on end-face image recognition and spatiotemporal registration, to solve the following technical problems in the prior art: Existing automatic roll changing control methods mostly adopt time synchronization, single-channel signal independent time delay compensation, or simple logic superposition of multiple detection signals control modes, without establishing a unified spatial position reference system. As a result, under high-speed operation, the time deviation of multiple asynchronous detection signals such as image detection, ultrasonic detection, and color difference detection gradually transforms into spatial offset on the label paper conveying path due to their inherent acquisition and calculation delays. This causes inconsistencies in the physical positions of the paper webs corresponding to different detection signals, leading to misalignment of the roll changing judgment benchmark, resulting in faults such as cutting point offset, uneven splicing of new and old paper rolls, and excessive tension fluctuations, affecting the continuous operation efficiency and production stability of the equipment.

[0008] To achieve the above objectives, embodiments of the present invention provide a trademark paper roll changing control method based on image recognition and spatiotemporal registration, comprising: Real-time acquisition of paper roll end face image data and multiple asynchronous detection signals; The remaining length and remaining available time of the paper roll are obtained based on the image data of the paper roll end face. Based on the instantaneous conveying speed of the label paper obtained by the encoder at the conveying end, a coordinate axis for the paper web conveying position is established, and dynamic position compensation is performed on the multi-channel asynchronous detection signals to uniformly map the asynchronous signals to the same physical position. Calculate the physical position deviation of each signal after mapping, and determine that the position consistency condition is met when the maximum deviation is less than a preset threshold. When the remaining available time reaches the preset preparation time and the position consistency condition is met, the volume switching execution is triggered.

[0009] Optionally, the multi-channel asynchronous detection signals include at least a label paper end mark detection signal and a paper layer thickness detection signal.

[0010] Optionally, obtaining the remaining length and remaining available time of the paper roll based on the end face image data includes: The remaining length of the paper roll is obtained according to formula (1). (1) in, This is the remaining length of the paper roll. for The remaining outer radius of the old paper roll at any given moment. To preset the paper core radius, Preset single sheet thickness; The remaining available time is obtained according to formula (2). (2) in, For the remaining available time, The instantaneous conveying speed of the label paper is collected in real time by the encoder.

[0011] Optionally, establishing the paper web conveying position coordinate axis includes: using a preset reference detection position as the coordinate zero point, and constructing a continuous paper web conveying position coordinate axis based on the instantaneous conveying speed.

[0012] Optionally, the step of performing dynamic position compensation on the multiple asynchronous detection signals to uniformly map the asynchronous signals to the same physical location includes: Obtain the time delay of each detection signal; The compensation amount corresponding to each detection signal is calculated based on the instantaneous conveying speed of the trademark paper; Based on the compensation amount corresponding to each detection signal, all asynchronous detection signals are mapped to their corresponding physical positions on a unified paper web position coordinate axis.

[0013] Optionally, before triggering the volume switching execution, a three-level early warning and pre-scheduling control is also included: When the remaining amount of paper rolls enters the warning range, a Level 1 warning is triggered, and a backup roll reminder is issued. When the remaining available time is less than or equal to the preset preparation time, the secondary preparation is triggered, and the pre-scheduling of the new paper roll is started. When the system is in the second-level preparation state, the remaining available time reaches the preset preparation time, and the position consistency condition is met, the volume switching is triggered.

[0014] Optionally, when the remaining available time is less than or equal to a preset preparation time, triggering a secondary preparation and initiating a new paper roll pre-schedule includes: The system controls the new paper roll at a certain speed. Pre-acceleration: ; in, For instantaneous delivery speed, The real-time radius of the old paper roll. The radius of the new paper roll, This is the reduction ratio.

[0015] Optionally, when the position consistency condition is not met, the roll change is paused and the current operating state is maintained until the position consistency condition is met again, at which point the roll change is initiated.

[0016] On the other hand, the present invention also provides an image recognition and spatiotemporal registration label paper roll changing control system, the system comprising: The end-face image recognition module is used to acquire paper roll end-face image data in real time; A multi-channel asynchronous detection module is used to synchronously acquire multiple asynchronous detection signals; The conveyor end encoder is used to obtain the instantaneous conveying speed of the label paper in real time; The data processing module is used to obtain the remaining available time of the old paper roll based on the end face image, establish the paper web conveying position coordinate axis based on the instantaneous conveying speed, and use it to perform dynamic position compensation on the multi-channel asynchronous detection signals, and uniformly map the asynchronous signals to the same physical position. The position consistency decision module is used to calculate the physical position deviation of each signal after mapping. When the maximum deviation is less than a preset threshold, the position consistency condition is determined to be met. The volume switching execution module is used to trigger the volume switching execution action when the remaining available time reaches the preset preparation time and the position consistency condition is met.

[0017] In another aspect, the present invention also provides a computer-readable storage medium storing instructions that, when executed by a processor, implement any of the methods described above.

[0018] The beneficial effects of this invention are: This invention provides a label paper roll changing control method based on image recognition and spatiotemporal registration. It establishes a paper web conveying position coordinate axis based on the encoder at the conveyor end and performs dynamic position compensation on multiple asynchronous detection signals, mapping the asynchronous signals to the same physical position. This eliminates spatial offset caused by inherent time delays in multiple signals, solves the problem of misaligned roll changing decision benchmarks, and significantly improves the accuracy of cutting and splicing positions. By calculating the physical position deviation of each signal after mapping, a position consistency condition is set with the maximum deviation less than a preset threshold. This, along with the remaining available time, constitutes a dual constraint for roll changing triggering, avoiding faults such as cutting offset, splicing wrinkling, and tension fluctuations caused by inconsistent signal positions. This reduces the frequency of paper breaks and abnormal shutdowns, ensuring continuous operation of the production line. When the position deviation does not meet the consistency condition, the system pauses roll changing and maintains the current operating state, forming a position deviation over-limit fault tolerance mechanism. Compared to traditional control methods with simple logic superposition, this method has stronger anti-interference capabilities and can adapt to complex operating conditions such as acceleration / deceleration, paper web slippage, and load fluctuations, significantly improving the stability of the control logic.

[0019] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 A flowchart of a trademark paper roll changing control method based on image recognition and spatiotemporal registration according to an embodiment of the present invention; Figure 2 A flowchart of a method for obtaining the remaining length and remaining available time of a paper roll based on the end face image data of the paper roll according to an embodiment of the present invention; Figure 3 This is a flowchart illustrating a method for uniformly mapping asynchronous signals to the same physical location according to an embodiment of the present invention; Figure 4 This is a schematic diagram of an image recognition and spatiotemporal registration label paper roll changing control system according to an embodiment of the present invention. Detailed Implementation

[0021] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0022] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with relevant laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0023] The embodiments of this invention are applied to the FOCKE-FXS series high-speed cigarette packaging machine. Without changing the main structure, transmission system, and forming station of the packaging machine, it relies on the original dual-station unwinding mechanism, label paper conveying channel, cutting and splicing execution mechanism, and adds an end face image recognition unit, color difference detection unit, ultrasonic thickness detection unit and PLC collaborative control unit to form a complete remaining amount detection and automatic roll changing control method.

[0024] like Figure 1 The diagram shows a flowchart of a trademark paper roll changing control method based on image recognition and spatiotemporal registration according to an embodiment of the present invention. Figure 1 The control method may include the following steps: In step S10, real-time acquisition of paper roll end face image data and multiple asynchronous detection signals is performed. In step S11, the remaining length and remaining available time of the paper roll are obtained based on the end face image data of the paper roll; In step S12, based on the instantaneous conveying speed of the label paper obtained by the encoder at the conveying end, a paper web conveying position coordinate axis is established, and dynamic position compensation is performed on the multiple asynchronous detection signals to uniformly map the asynchronous signals to the same physical position. In step S13, the physical position deviation of each signal after mapping is calculated, and the position consistency condition is determined to be met when the maximum deviation is less than a preset threshold. In step S14, when the remaining available time reaches the preset preparation time and the position consistency condition is met, the volume switching is triggered.

[0025] In such Figure 1 In the illustrated image recognition and spatiotemporal registration method for controlling the roll changing of trademark paper, step S10 is used to acquire real-time image data of the paper roll end face and multiple asynchronous detection signals. In this embodiment, the specific method for acquiring the paper roll end face image data can be to use a global shutter CCD industrial camera, paired with an 8mm fixed-focus industrial lens with an adjustable aperture of F2.8-F16; the light source is a 24V DC white ring low-angle light source, and the illumination angle is set to... to To enhance the contrast of the paper roll end face edge, the camera is side-mounted to the old paper roll unwinding frame, with the optical axis pointing vertically to the center of the paper roll end face, and the working distance is set to 120mm-180mm. The camera is equipped with a fully enclosed metal light-shielding dustproof cover, with a micro-positive pressure air curtain inside the cover to continuously blow and clean the lens and end face area, preventing dust, lint, and oil stains from affecting the detection stability.

[0026] Furthermore, the multi-channel asynchronous detection signals include at least the label paper end mark detection signal and the paper layer thickness detection signal. Specifically, in this example, the acquisition method of the label paper end mark detection signal can be: using a high-precision RGB color difference sensor with a response time of less than 1ms, installed directly above the label paper conveying channel, located 150mm downstream of the old paper roll unwinding mechanism, with the detection spot aligned with the center area of ​​the label paper surface.

[0027] In this example, the paper thickness detection signal can be acquired by using a 10MHz high-frequency non-contact ultrasonic thickness sensor with a measurement range of 0.05mm-0.5mm, installed 50mm downstream of the color difference sensor, maintaining a 3mm gap from the label paper surface. By detecting paper thickness, density, and overlapping or loose defects, the roll-changing trigger signal is redundantly checked, improving the system's fault tolerance under high-speed dynamic conditions.

[0028] Step S11 is used to obtain the remaining length and remaining available time of the paper roll based on the paper roll end-face image data. In this embodiment, the specific method for obtaining the remaining length and remaining available time of the paper roll based on the paper roll end-face image data in step S11 can be of various forms known to those skilled in the art. In one example of the present invention, step S11 may include, for example... Figure 2 The steps shown are described. Figure 2 In this context, step S11 may include: In step S20, the image data of the paper roll end face is preprocessed; In step S21, the physical radius is obtained based on the preprocessed image data; In step S22, the remaining length of the paper roll and the remaining available time are calculated based on the physical radius.

[0029] In such Figure 2 In the method shown, step S20 is used to preprocess the paper roll end face image data. Specifically, in this example, the preprocessing method may include: grayscale conversion and Gaussian filtering to reduce noise and preserve edges; distortion correction, using calibration coefficients for real-time correction; automatic thresholding to separate the end face from the background; and edge extraction to obtain the outer circle and inner hole contours.

[0030] Step S21 is used to obtain the physical radius based on the preprocessed image data. Specifically, in this example, the pixel radius is obtained by least-squares circle center fitting, and then the physical radius is converted to obtain... .

[0031] Step S22 is used to calculate the remaining length of the paper roll and the remaining available time based on the physical radius. Specifically, in this example, the remaining length of the paper roll can be obtained according to formula (1): (1) in, This is the remaining length of the paper roll. for The remaining outer radius of the old paper roll at any given moment. To preset the paper core radius, Preset single sheet thickness; The remaining available time can be obtained using formula (2): (2) in, For the remaining available time, The instantaneous conveying speed of the label paper is collected in real time by the encoder.

[0032] In the high-speed continuous conveying operation of the FXS packaging machine, traditional roll-changing control generally uses the instantaneous trigger moment of a single sensor as the basis for roll-changing execution. It assumes that various detection signals synchronously correspond to the same physical position of the paper web, and roll-changing decisions are made solely based on a single threshold judgment or simple superposition of multiple signals. However, under high-speed operation, the response characteristics of different detection units have inherent differences: end-face image acquisition and contour fitting have fixed calculation delays, ultrasonic thickness measurement has hardware sampling delays, and color difference mark detection is an instantaneous response. These three types of detection signals naturally have asynchronous deviations. As the production line speed increases, tiny time differences are continuously amplified into significant spatial offsets, causing the detection results of different sensors to correspond to different physical positions on the label paper conveying path. This leads to production failures such as end-marker recognition misalignment, cutting offset, splicing alignment deviation, and false roll-changing triggers, making it impossible to guarantee roll-changing accuracy and production stability under high-speed conditions.

[0033] Therefore, to overcome the shortcomings of traditional instantaneous triggering decision logic, this invention establishes a full-link spatiotemporal registration mechanism with a unified time base, encoder position reference, and dynamic speed feedforward compensation in step S12. This maps all asynchronous detection signals to the same physical position of the paper web before executing the roll change decision, thus solving the industry problem of multi-source detection signal mismatch under high-speed dynamic conveying conditions from the control mechanism level. In step S12, a paper web conveying position coordinate axis is established based on the instantaneous conveying speed of the label paper obtained by the encoder at the conveying end. Specifically, in this example, the preset reference detection position is used as the coordinate zero point. A continuous paper web conveying position coordinate axis is constructed based on the instantaneous conveying speed. By setting up an encoder position index mapping mechanism, a standardized and practical dedicated spatial alignment benchmark is established, overcoming the shortcomings of traditional compensation schemes that lack a fixed physical benchmark and have poor adaptability. The equipment conveying end is equipped with a high-precision encoder, and the PLC collects the encoder pulse signals in real time, accumulates and calculates the continuous conveying length of the label paper, and establishes a unique and continuous paper web conveying position coordinate axis as a unified position benchmark for all detection signals.

[0034] Next, dynamic position compensation is performed on the multiple asynchronous detection signals based on the paper web conveying position coordinate axis, uniformly mapping the asynchronous signals to the same physical position. In this embodiment, the specific method for uniformly mapping the asynchronous signals to the same physical position in step S12 can be of various forms known to those skilled in the art. In one example of the present invention, this step may include, for example... Figure 3 The steps shown are described. Figure 3 In this process, this step may include: In step S30, the time delay of each detection signal is obtained; In step S31, the compensation amount corresponding to each detection signal is calculated based on the instantaneous conveying speed of the trademark paper; In step S32, based on the compensation amount corresponding to each detection signal, all asynchronous detection signals are mapped to their corresponding physical positions on a unified paper web position coordinate axis.

[0035] In such Figure 3 In the method shown, step S30 is used to obtain the time delay of each detection signal. Specifically, in this example, the visual processing time delay... 1. Ultrasonic sampling delay It can be obtained through system calibration, offline testing or real-time measurement during equipment operation, and stored in the control parameter table for real-time compensation by the system.

[0036] Step S31 is used to calculate the compensation amount corresponding to each detection signal based on the instantaneous conveying speed of the label paper, combined with the real-time instantaneous linear speed of the production line. Dynamic position compensation is performed on visual and ultrasonic detection signals with fixed time delays to eliminate spatial deviations caused by the time delay. The specific compensation formula is as follows: , The linear velocity calculated for all positions is determined by the instantaneous conveying speed collected in real time by the encoder. This allows for precise adaptation to non-uniform dynamic conditions during production, such as acceleration / deceleration, tension fluctuations, and slight paper web slippage, thereby reducing compensation errors caused by constant speed calculations.

[0037] Step S32 is used to map all asynchronous detection signals to their corresponding physical positions on a unified paper web position coordinate axis based on the compensation amount corresponding to each detection signal. Specifically, after corresponding time delay compensation, each detection signal is mapped to its corresponding physical position on the unified paper web position coordinate axis. Through a closed-loop mechanism of real-time encoder position indexing and dynamic speed compensation, the three types of asynchronous detection signals are precisely aligned in terms of time and space, adapting to high-speed dynamic conveying conditions.

[0038] This registration mechanism differs from conventional control logic that relies on single-moment triggering and simple signal superposition. It closely integrates with the unique operating conditions of high-speed continuous cigarette material transport. Through a closed-loop control logic of real-time timing calibration, dynamic position conversion, unified spatial mapping, and position consistency verification, it transforms discrete, asynchronous, and misaligned multi-source detection data into a valid basis for determining the same paper web position. Traditional control methods based on fixed delay compensation or single-moment synchronous triggering can only achieve alignment at the signal time level, failing to guarantee that different detection results correspond to the same physical position of the paper web during high-speed dynamic transport.

[0039] The embodiments of the present invention establish a unified spatial reference by encoder position index, realize the physical position consistency verification of multi-source detection results, and provide key technical support for accurate and stable roll change decision under high-speed conditions.

[0040] Step S13 is used to calculate the physical position deviation of each signal after mapping. When the maximum deviation is less than a preset threshold, it is determined that the position consistency condition is met. Specifically, in this embodiment of the invention, after converting multiple asynchronous detection signals to the same paper web space coordinates, consistency constraint judgment is performed based on the correspondence between the positions of multiple signals, which is different from the conventional automated control logic that only performs independent time delay correction on a single detection signal. The system calculates the absolute distance between the physical positions of each detection signal after mapping, obtains the position deviation between each group of signals, and when the maximum value of each group of position deviations is less than a preset allowable error threshold, it is determined that multiple detection signals correspond to the same physical position on the paper web and meet the position consistency condition, and outputs a valid roll change judgment basis.

[0041] Step S14 is used to trigger roll replacement execution when the remaining available time reaches the preset preparation time and the location consistency condition is met. Before triggering roll replacement execution, a three-level early warning and pre-scheduling control is performed. In this example, the system divides the operating status into three categories: normal operation, preparation for roll replacement, and execution of roll replacement. It performs association constraint judgment based on the unified physical location signal after spatiotemporal registration, and completes multi-signal joint judgment based on the unified physical location correspondence. The judgment logic includes: When the remaining amount of paper rolls enters the warning range, a Level 1 warning is triggered, and a backup roll reminder is issued. When the remaining available time is less than or equal to the preset preparation time, the second-level preparation is triggered, and the pre-scheduling of the new paper roll is started. When the system is in the second-level preparation state, the remaining available time reaches the preset preparation time, and the position consistency condition is met, the volume replacement is triggered.

[0042] Traditional roll changing is a passive, end-triggered process, lacking a pre-synchronization process for the new roll. This can easily lead to sudden tension changes, speed shocks, and splicing misalignment at high speeds. The embodiment of this invention employs a remaining time prediction and pre-scheduling synchronization mechanism to establish a dynamic equilibrium state for the new roll before the roll changing action occurs, achieving shock-free splicing. Specifically, the pre-scheduling activation condition is: ; in: Preparation time for pre-scheduling, Allow sufficient time for safety.

[0043] Next, a new and old winding speed synchronization model is adopted, requiring the splicing time to meet the following requirements: .

[0044] The rotation speed of the new roll is:

[0045] In the formula: For the real-time radius of the old roll, For the real-time radius of the new volume, Reduction ratio The tension feedback adjustment servo cylinder is achieved through a tension closed-loop control model to maintain stable tension during the conveying process and ensure flatness of the paper web during splicing.

[0046] In the embodiments of the present invention, to ensure the continuity and safety of high-speed production, the image recognition and spatiotemporal registration trademark paper roll changing control method also includes an anomaly handling mechanism: when a single mode fails, the remaining dual modes can still complete the position consistency judgment without interrupting production; when multimodal signal contradictions occur and signal conflicts arise, the system automatically enters the safe roll changing mode; when speed or tension exceeds the tolerance and causes synchronization abnormality, the splicing action is paused and synchronization control is re-executed; when the cutting or pressing action times out and an execution failure occurs, an alarm is immediately triggered and the system enters the protection state; when the end face is contaminated by dust, continuous protection is provided by an air curtain, and an early warning is triggered when continuous recognition fails; when a power outage or emergency stop occurs, the system maintains the current state parameters, and can continue to perform roll changing after power is restored, avoiding paper roll waste.

[0047] Example: The initial state of the system is: the initial radius of the old paper roll. paper core radius single sheet thickness Conveyor line speed The target tension is 15N.

[0048] When the real-time radius of the old paper roll When the length drops to 186.4mm, calculate the remaining length. The remaining length is compared to This triggers a Level 1 warning, and the system issues a backup document prompt.

[0049] As paper rolls continue to be consumed. When reduced to 122mm, the remaining length The remaining length is compared to Remaining available time The secondary preparatory conditions are met, and the system enters the pre-roll change state. Pre-acceleration of the new paper roll is initiated, and the new roll speed... At the same time, tension closed-loop control is introduced to synchronize the surface linear speed of the new roll with the conveyor linear speed, thereby maintaining stable paper web tension.

[0050] When the remaining available time reaches the preset preparation time, and the color difference mark detection is effective, the ultrasonic thickness detection is normal, and the three detection signals after spatiotemporal registration meet the position consistency condition, the system triggers the roll change. After the old and new paper rolls are synchronized, the speed deviation and tension fluctuation are controlled within the allowable range, and the entire process of cutting, splicing, and resetting is completed stably without downtime, impact, paper breakage, or offset.

[0051] On the other hand, the present invention also provides an image recognition and spatiotemporal registration label paper roll changing control system, the system architecture diagram of which is shown below. Figure 4 As shown, the system includes: an end-face image recognition module, a multi-channel asynchronous detection module, a conveyor encoder, a data processing module, a position consistency judgment module, and a roll change execution module. The end-face image recognition module is used to acquire real-time image data of the paper roll's end face. The multi-channel asynchronous detection module is used to synchronously acquire multiple asynchronous detection signals. The conveyor encoder is used to obtain the instantaneous conveying speed of the label paper in real time. The data processing module is used to obtain the remaining available time of the old paper roll based on the end-face image, establish a paper web conveying position coordinate axis based on the instantaneous conveying speed, and use this to perform dynamic position compensation on the multiple asynchronous detection signals, mapping the asynchronous signals to the same physical position. The position consistency judgment module is used to calculate the physical position deviation of each signal after mapping; when the maximum deviation is less than a preset threshold, the position consistency condition is determined to be met. The roll change execution module is used to trigger the roll change execution action when the remaining available time reaches a preset preparation time and the position consistency condition is met.

[0052] Furthermore, the end-face image recognition module includes a global shutter CCD industrial camera, paired with an 8mm fixed-focus industrial lens with an adjustable aperture of F2.8-F16; the light source uses a 24V DC white ring low-angle light source, with the illumination angle set to... to To enhance the contrast of the paper roll end face edge, the camera is side-mounted to the old paper roll unwinding frame, with the optical axis pointing vertically to the center of the paper roll end face, and the working distance is set to 120mm-180mm. The camera is equipped with a fully enclosed metal light-shielding dustproof cover, with a micro-positive pressure air curtain inside the cover to continuously blow and clean the lens and end face area, preventing dust, lint, and oil stains from affecting the detection stability.

[0053] Furthermore, the multi-channel asynchronous detection module includes an RGB color difference detection unit and an ultrasonic thickness detection unit. The RGB color difference detection unit uses a high-precision RGB color difference sensor with a response time of less than 1ms. It is installed directly above the label paper conveying channel, 150mm downstream of the old paper roll unwinding mechanism, with the detection spot aligned with the center area of ​​the label paper surface. This unit is used for positioning detection of the end mark of the paper roll; the output signal is not used as a separate basis for roll changing, but only as one of the input signals for multimodal position consistency determination. The ultrasonic thickness detection unit uses a 10MHz high-frequency non-contact ultrasonic thickness sensor with a measurement range of 0.05mm-0.5mm. It is installed 50mm downstream of the color difference sensor, maintaining a 3mm distance from the label paper surface. This unit is used to detect paper layer thickness, density, overlapping or loose defects, and performs redundant verification of the roll changing trigger signal, improving the system's fault tolerance under high-speed dynamic conditions.

[0054] Furthermore, the roll-changing execution module includes servo unwinding motors for both old and new paper rolls, a tension-adjusting servo cylinder, a high-speed pneumatic passivation cutter, a tape length-fixed traction mechanism, and a silicone pressing mechanism. The human-machine interface uses a 10-inch touchscreen for parameter input, status display, early warning prompts, and data recording. The PLC uses a controller supporting industrial real-time bus, with a synchronization cycle of 1ms. Vision processing is independently completed by an embedded ARM-FPGA architecture controller, without consuming PLC computing resources.

[0055] After the system is powered on, the following standardized initialization and calibration procedures are performed to ensure detection accuracy and control stability: First, configure the basic parameters of the paper roll, and enter the initial outer radius. Paper core radius single sheet thickness The paper roll is fixed with parameters such as a first-level warning threshold, a second-level preparatory threshold, a color difference recognition threshold, an ultrasonic thickness reference range, a target tension range, and a linear speed synchronization allowable deviation.

[0056] Subsequently, vision system calibration was carried out: standard gauge blocks were placed within the camera's field of view for pixel equivalent calibration, images were acquired and pixel widths were calculated to determine the conversion relationship between pixels and physical dimensions; radial distortion coefficients were obtained through calibration algorithms, and real-time distortion correction was performed on the images to eliminate radius calculation errors introduced by lens distortion; hollow shaft images were acquired, and the center coordinates were fitted using the least squares method as a fixed reference for subsequent paper roll radius calculations.

[0057] Next, the threshold calibration of the multimodal sensors is completed: the color difference sensor collects the background color of the label paper and the color block of the end mark, sets the dynamic recognition threshold, and has the ability to adaptively compensate for ambient light drift; the ultrasonic sensor calibrates the reference value of the thickness of a single sheet of paper, sets the allowable deviation range, and judges the paper layer as abnormal when it exceeds the range; the tension mechanism calibrates the target tension and the allowable range of fluctuation, and the speed system calibrates the synchronization deviation threshold.

[0058] Finally, control parameters are tuned, including setting tension closed-loop PID parameters, pre-scheduling preparation time, safety margin time, cutting delay, pressing delay, and the upper limit of total roll change sequence.

[0059] In another aspect, the present invention also provides a computer-readable storage medium storing instructions that, when executed by a processor, implement any of the methods described above.

[0060] The beneficial effects of this invention are: This invention is adapted to a specific production scenario involving high-speed roll changing, precise cutting, and seamless splicing of cigarette label paper. It uses the remaining amount and time of the paper roll obtained from end-face image detection as the basis for judgment. Through a spatiotemporal registration mechanism of real-time encoder position indexing and dynamic speed feedforward compensation, it completes the physical position consistency verification of multiple asynchronous detection signals. Simultaneously, combined with predictive pre-scheduling synchronous control based on remaining time, it achieves dynamic synchronization of the speed and tension of the new and old paper rolls before the roll changing is executed. This forms a complete closed-loop control system of state prediction, spatiotemporal calibration, consistency verification, and pre-synchronization switching, specifically addressing the practical industrial problems of multi-source asynchronous detection signal mismatch, insufficient roll changing accuracy, and poor equipment operational stability in high-speed conveying scenarios.

[0061] This invention abandons the traditional time synchronization and single-channel independent delay compensation mode. It relies on an encoder to construct a unified position coordinate axis across the entire domain, spatially mapping detection signals with different delays one by one. Using the maximum positional deviation between signals as the judgment criterion, it completely solves the problem of misaligned decision benchmarks caused by time differences being converted into spatial offsets. The accuracy of cutting and splicing positions is significantly improved. Field tests show that the positional deviation between the label paper detection point and the actual cutting station can be controlled within the allowable range of the process. Under high-speed label paper conveying conditions, this solution can effectively avoid problems such as cutting offset, splicing wrinkles, and sudden tension changes caused by inconsistent positions. After applying this method, paper breaks and abnormal shutdowns related to label paper roll changes are significantly reduced, increasing the effective operating time of the equipment and reducing the time lost due to troubleshooting and equipment restarts.

[0062] This invention adds a position deviation over-limit fault tolerance mechanism. When the positions of multiple signals do not meet the consistency requirements, the system automatically pauses the roll changing action and re-verifies to avoid erroneous roll changing operations. Compared with the traditional control method of simple logical AND-OR judgment, this control logic has stronger anti-interference ability and can adapt to complex working conditions such as acceleration and deceleration, paper web micro-slippage, and load fluctuation in the production site, significantly improving the reliability of control operation.

[0063] This invention's technical solution is based on existing general-purpose industrial hardware such as image detection, ultrasonic detection, color difference detection, encoders, and PLCs. It requires no replacement of specialized equipment or significant modification of the mechanical structure; only the control program and computational logic need to be optimized for practical application. The solution is compatible with the label paper conveying layout of different models, and the benchmark detection points can be flexibly adjusted. Its low barrier to entry and strong engineering practicality make it highly applicable. Improved roll-changing accuracy significantly reduces the amount of waste edges from label paper cutting and defective splicing, effectively controlling roll material loss. Simultaneously, equipment downtime is shortened, ensuring unit-time production capacity. The manpower required for manual inspection and troubleshooting is also reduced accordingly. This reduces overall operating costs from multiple dimensions—materials, labor hours, and maintenance—resulting in considerable economic benefits and effectively improving continuous equipment operating efficiency and roll material utilization.

[0064] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0065] 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 flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0066] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0067] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0068] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0069] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0070] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0071] 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.

[0072] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for controlling trademark paper roll changing based on image recognition and spatiotemporal registration, characterized in that, The method includes: Real-time acquisition of paper roll end face image data and multiple asynchronous detection signals; The remaining length and remaining available time of the paper roll are obtained based on the image data of the paper roll end face. Based on the instantaneous conveying speed of the label paper obtained by the encoder at the conveying end, a coordinate axis for the paper web conveying position is established, and dynamic position compensation is performed on the multi-channel asynchronous detection signals to uniformly map the asynchronous signals to the same physical position. Calculate the physical position deviation of each signal after mapping, and determine that the position consistency condition is met when the maximum deviation is less than a preset threshold. When the remaining available time reaches the preset preparation time and the position consistency condition is met, the volume switching execution is triggered.

2. The method according to claim 1, characterized in that, The multi-channel asynchronous detection signals include at least the label paper end mark detection signal and the paper layer thickness detection signal.

3. The method according to claim 1, characterized in that, The remaining length and remaining available time of the paper roll are obtained based on the end face image data of the paper roll, including: The remaining length of the paper roll is obtained according to formula (1). ，（1） in, This is the remaining length of the paper roll. for The remaining outer radius of the old paper roll at any given moment. To preset the paper core radius, Preset single sheet thickness; The remaining available time is obtained according to formula (2). ，（2） in, For the remaining available time, The instantaneous conveying speed of the label paper is collected in real time by the encoder.

4. The method according to claim 1, characterized in that, The establishment of the paper web conveying position coordinate axis includes: using a preset reference detection position as the coordinate zero point, and constructing a continuous paper web conveying position coordinate axis based on the instantaneous conveying speed.

5. The method according to claim 1, characterized in that, The step of performing dynamic position compensation on the multiple asynchronous detection signals, mapping the asynchronous signals uniformly to the same physical location, includes: Obtain the time delay of each detection signal; The compensation amount corresponding to each detection signal is calculated based on the instantaneous conveying speed of the trademark paper; Based on the compensation amount corresponding to each detection signal, all asynchronous detection signals are mapped to their corresponding physical positions on a unified paper web position coordinate axis.

6. The method according to claim 1, characterized in that, Before triggering the volume switching execution, a three-level early warning and pre-scheduling control is also included: When the remaining length of the paper roll enters the warning range, a level one warning is triggered, and a spare roll prompt is issued; When the remaining available time is less than or equal to the preset preparation time, the secondary preparation is triggered, and the pre-scheduling of the new paper roll is started. When the system is in the second-level preparation state, the remaining available time reaches the preset preparation time, and the position consistency condition is met, the volume switching is triggered.

7. The method according to claim 6, characterized in that, When the remaining available time is less than or equal to the preset preparation time, the secondary preparation is triggered, and the pre-scheduling of the new paper roll is initiated, including: The system controls the new paper roll at a certain speed. Pre-acceleration: ； in, For instantaneous delivery speed, The real-time radius of the old paper roll. The radius of the new paper roll. This is the reduction ratio.

8. The method according to claim 1 or 6, characterized in that, If the position consistency condition is not met, the roll change is paused and the current operating state is maintained until the position consistency condition is met again, at which point the roll change is initiated.

9. A label paper roll changing control system based on image recognition and spatiotemporal registration, characterized in that, The system includes: The end-face image recognition module is used to acquire paper roll end-face image data in real time; A multi-channel asynchronous detection module is used to synchronously acquire multiple asynchronous detection signals; The conveyor end encoder is used to obtain the instantaneous conveying speed of the label paper in real time; The data processing module is used to obtain the remaining available time of the old paper roll based on the end face image, establish the paper web conveying position coordinate axis based on the instantaneous conveying speed, and use it to perform dynamic position compensation on the multi-channel asynchronous detection signals, and uniformly map the asynchronous signals to the same physical position. The position consistency decision module is used to calculate the physical position deviation of each signal after mapping. When the maximum deviation is less than a preset threshold, the position consistency condition is determined to be met. The volume switching execution module is used to trigger the volume switching execution action when the remaining available time reaches the preset preparation time and the position consistency condition is met.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed by a processor, implement the method as described in any one of claims 1 to 8.

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