A cigarette packet bottom surface defect visual detection device and method based on a cigarette packet posture conversion station

Abstract

The application discloses a kind of based on cigarette packet posture conversion station's cigarette packet bottom surface defect vision detection device and method.The present application utilizes the process requirement of downstream equipment to cigarette packet flat feeding, industrial intelligent camera and in-place photoelectric switch are deployed in the posture conversion station between chamfering device and downstream equipment entrance, take a photo when in-place photoelectric switch is triggered when cigarette packet is chamfered, identify scratch, defect such as stain;By photoelectric coupler, send the rejection signal to the original packaging machine control system, call the original machine rejection mechanism to complete rejection, and have continuous defect alarm function.The present application can realize the on-line full inspection of cigarette packet bottom surface without modifying the original equipment, fill the sixth surface detection blind area of cigarette packet, with the advantages of low cost, strong versatility, no interference production rhythm.

Description

Technical Field

[0001] This invention belongs to the field of cigarette manufacturing technology, specifically relating to a visual inspection device and method for defects on the bottom surface of cigarette packs based on a cigarette pack posture conversion station. Background Technology

[0002] In the cigarette packaging production process, after the cigarette packs are packaged and formed by the packaging machine, they typically enter the belt conveyor channel (i.e., the cigarette pack transfer channel composed of conveyor belts) in a side-standing position. They are then transferred by this conveyor belt to downstream processing equipment such as transparent paper packaging machines and carton packaging machines to complete subsequent packaging processes. To meet the assembly requirements of these downstream equipment for flat-lying cigarette pack feeding, existing production lines generally have a cigarette pack chamfering device near the inlet of the downstream equipment in the conveyor channel. This chamfering device smoothly converts the side-standing cigarette packs into a flat-lying position before they are fed into the inlet of the downstream equipment.

[0003] To strictly control the appearance quality of cigarette packs and prevent defective packs from entering subsequent processes and affecting the quality of the finished product, the industry generally deploys visual inspection devices for cigarette pack appearance at the conveyor channel of the packaging machine exit. These devices perform online automated defect detection on five visible surfaces: the front, back, top, bottom, and top side. This five-sided inspection device can effectively identify common appearance defects on the cigarette pack surface, including but not limited to scratches on the packaging film, surface stains, misaligned packaging paper, missing seals, edge dents, and blurry printing. Defective packs are promptly removed online, achieving initial control over the appearance quality of the cigarette packs. However, when the cigarette packs are conveyed in a side-standing position, the bottom side, which is in close contact with the conveyor belt, is completely obscured by the belt, preventing the visual imaging equipment from capturing a clear and effective inspection image. This results in the bottom side remaining uninspected for extended periods, becoming a weak link in the control of cigarette pack appearance quality.

[0004] In actual production, the conveying distance of cigarette packs from the packaging machine outlet to the chamfering device is relatively long. During this process, the bottom side of the cigarette pack continuously rubs against the belt, making it susceptible to dust, oil, and foreign objects in the channel, resulting in new hidden defects such as scratches, dirt, and abrasions. However, the existing chamfering device only realizes the orientation change of the cigarette pack and does not have the function of defect identification and detection. As a result, such bottom surface defects cannot be captured by the front-end five-sided detection and flow directly into the downstream process with qualified cigarette packs, creating potential batch quality hazards.

[0005] To address the issue of blind spot detection on the bottom of cigarette packs, existing improvement solutions often involve adding independent flipping tracks, deploying multi-camera networks, modifying the perforated conveyor belt, and installing bottom-mounted imaging modules to achieve six-sided supplementary inspection. These modifications require significant alterations to the original conveyor lines and the addition of complex mechanical tooling and imaging equipment. This not only results in high modification costs and long implementation cycles but also easily interferes with the existing production cycle and has poor compatibility with mainstream models such as GDX1 and GDX2, as well as various cigarette pack specifications. Other companies use manual, fixed-point sampling inspections to control bottom quality, which suffers from low efficiency, insufficient coverage, and high rates of missed and false detections, failing to meet the full inspection control requirements of high-speed automated production lines.

[0006] This application is submitted to address the aforementioned issues. Summary of the Invention

[0007] To address the shortcomings of existing technologies where defects on the bottom surface of cigarette packs cannot be detected due to obstruction by the conveyor belt, requiring significant production line modifications for supplementary inspection, resulting in high modification costs and poor versatility, or where manual sampling is inefficient and prone to errors, this invention provides a visual inspection device and method for bottom surface defects of cigarette packs based on a cigarette pack posture conversion station. This device and method align with the downstream equipment's process requirement for flat-feeding of cigarette packs. Utilizing the posture conversion opportunity when the bottom and sides of the cigarette pack are naturally exposed after chamfering, it achieves reliable and efficient online full inspection of bottom and side surface defects of cigarette packs without modifying the original conveyor belt and main equipment. This fills the blind spots in the complete appearance inspection of the six outer surfaces of the cigarette pack (i.e., front, back, top, bottom, top side, and bottom side), enabling comprehensive control of cigarette pack appearance and improving the quality control level of cigarette packaging.

[0008] The technical solution adopted in this invention is as follows:

[0009] The first aspect of this invention provides a visual inspection device for bottom surface defects of cigarette packs based on a cigarette pack posture conversion station. The device includes a chamfering device 1, which is installed on a conveyor channel 2 between the packaging machine outlet and downstream equipment. The chamfering device 1 is used to convert a side-standing cigarette pack into a lying position before it enters the downstream equipment inlet. The conveyor channel area between the output end of the chamfering device 1 and the downstream equipment inlet forms a posture conversion station. This posture conversion station refers to the conveyor channel area before the cigarette pack enters the downstream equipment after the posture conversion is completed by the chamfering device 1. In this area, the cigarette pack is in a lying position, and its bottom side, originally in contact with the conveyor belt, is completely exposed to the side of the conveyor channel. The device also includes an industrial intelligent camera 3, a cigarette pack positioning photoelectric switch 4, an optocoupler, and a controller. The cigarette pack positioning photoelectric switch 4 and the industrial intelligent camera 3 are sequentially arranged along the cigarette pack conveying direction on the side of the conveyor channel 2 at the posture conversion station.

[0010] The transmitter and receiver of the photoelectric switch 4 for cigarette pack placement are respectively installed on both sides of the conveying channel 2, and its optical path spans the conveying channel 2 along the width direction of the conveying channel and is perpendicular to the cigarette pack conveying direction.

[0011] The industrial intelligent camera 3 is installed on one side of the conveying channel 2 corresponding to the exposed bottom side of the cigarette pack. Its lens center is horizontally arranged and perpendicular to the conveying direction of the cigarette pack, and the lens faces the exposed bottom side of the flat cigarette pack.

[0012] The controller and optocoupler are installed inside the existing packaging machine's electrical cabinet. The controller's signal input terminal is connected to the output terminal of the cigarette pack positioning photoelectric switch 4 and the output terminal of the industrial intelligent camera 3, respectively. The controller's signal output terminal is connected to the signal input terminal of the existing packaging machine control system via the optocoupler. The optocoupler is used to achieve electrical isolation between the controller and the existing packaging machine control system, avoiding signal interference or potential mismatch, while eliminating the need for hardware modifications to the original control system.

[0013] Preferably, it also includes two sets of symmetrically arranged photoelectric switch mounting brackets, each set of photoelectric switch mounting brackets including a base plate 5 and a vertical plate 6 that are perpendicularly fixed to each other;

[0014] The base plate 5 has a transverse elongated hole 7 extending along the tobacco pack conveying direction. Fastening screws 8 are inserted into the transverse elongated hole 7, which can lock the base plate 5 to different positions on the side wall of the conveying channel 2, thereby realizing the position adjustment of the base plate 5 along the tobacco pack conveying direction. The vertical plate 6 has a vertical elongated hole 9 extending in the vertical direction.

[0015] The transmitter and receiver of the photoelectric switch 4 are respectively mounted on the vertical plates 6 of the photoelectric switch mounting brackets on both sides through fastening screws 8 that pass through the vertical elongated holes 9 of the corresponding side vertical plates 6, and the installation height can be adjusted by sliding along the vertical elongated holes 9.

[0016] Preferably, it also includes a camera mounting bracket, which includes a base 10 and a camera fixing plate 11 that are perpendicularly fixed to each other;

[0017] The base 10 has a transverse adjustment hole 12 extending along the cigarette pack conveying direction. The fastening screw 13 passes through the transverse adjustment hole 12, which can lock the base 10 to different positions on the side wall of the conveying channel 2, thereby realizing the position adjustment of the industrial intelligent camera 3 along the cigarette pack conveying direction.

[0018] The camera mounting plate 11 has an arc-shaped adjustment hole 14, and the fastening screw 13 passes through the arc-shaped adjustment hole 14. The industrial intelligent camera 3 can be locked to different angle positions on the camera mounting plate 11 to achieve angle calibration of the camera lens optical axis and ensure that the lens is accurately aligned with the exposed side of the cigarette pack.

[0019] Preferably, the signal output terminal of the controller includes a defect signal output terminal and an alarm signal output terminal; the defect signal output terminal is connected to the control input terminal of the original packaging machine's rejection mechanism via an optocoupler; the alarm signal output terminal is connected to the control input terminal of the original packaging machine's audible and visual alarm module via an optocoupler.

[0020] The second aspect of this invention provides a visual inspection method for defects on the bottom surface of a cigarette pack based on a cigarette pack posture conversion station, applied to the inspection device described in the first aspect, comprising the following steps:

[0021] S1. The cigarette pack enters the chamfering device 1 in a side-standing position. After being guided by the chamfering device 1, it is converted into a flat position for output, with the bottom side of the cigarette pack that was originally attached to the conveyor belt exposed to the outside.

[0022] S2. The cigarette pack in a flat position enters the posture conversion station along the conveyor channel 2, blocking the light path of the cigarette pack positioning photoelectric switch 4. The cigarette pack positioning photoelectric switch 4 sends a trigger signal to the controller.

[0023] S3. After receiving the trigger signal, the controller sends a photo-taking command to the industrial intelligent camera 3. The industrial intelligent camera 3 takes a photo of the bottom side of the cigarette pack and outputs the image.

[0024] The S4 industrial intelligent camera 3's built-in image processing module performs defect identification on the image, determines whether there are bottom surface defects, and sends the judgment result signal to the controller;

[0025] S5. If the judgment result is qualified, the controller does not output an action signal, and the cigarette pack enters the downstream equipment normally; if the judgment result is defective, the controller sends a defect rejection signal to the original packaging machine control system through the defect signal output terminal via the optocoupler; the controller communicates with the human-machine interface of the original packaging machine for parameter setting and status viewing.

[0026] S6. The original packaging machine control system calculates the delay time based on the defect rejection signal, combined with the cigarette pack conveying distance and speed. When the defective cigarette pack is conveyed to the rejection station, it controls the original machine's rejection solenoid valve to activate, thereby driving the rejection mechanism to reject the defective cigarette pack; delay time. Where L is the conveying distance from the inspection station to the rejection station, and V is the conveying speed of the cigarette pack.

[0027] S7. The controller counts the number of consecutive defective cigarette packs in real time. When the number of consecutive defective cigarette packs reaches a preset threshold, the controller sends an alarm signal to the original packaging machine control system via an optocoupler through the alarm signal output terminal, triggering the audible and visual alarm module. This preset threshold can be set to an integer between 3 and 10 to avoid frequent alarms caused by occasional false detections, while ensuring timely early warning when there are consecutive batches of defects.

[0028] Preferably, in step S4, the image processing module compares the collected image of the bottom side of the cigarette pack with the pre-stored standard template image pixel by pixel, calculates the area and grayscale difference of the difference region, and determines that there is a defect when the area of ​​the difference region exceeds a preset area threshold or the grayscale difference exceeds a preset grayscale threshold.

[0029] Preferably, in step S6, the original packaging machine control system calculates the delay time based on the conveying distance and conveying speed of the cigarette pack from the posture conversion station to the rejection station, and controls the rejection mechanism to operate when the delay time is reached.

[0030] The advantages of this invention over the prior art are as follows:

[0031] 1. This invention utilizes the inherent process requirement of horizontal feeding in downstream equipment during the cigarette pack conveying process, and deploys a visual inspection device at the posture conversion station between the chamfering device and the downstream equipment inlet. It achieves online automated inspection of the bottom and side surfaces of the cigarette packs without any destructive mechanical modifications to the original conveyor belt, chamfering device, or main equipment. This has the advantages of low modification cost, short implementation cycle, and no disruption to the original production cycle.

[0032] 2. This invention fills the blind spot in the detection of the bottom side of the cigarette pack, which cannot be covered by existing five-sided visual inspection devices. This bottom side is the side of the cigarette pack that is in close contact with the conveyor belt during side-standing transport and is always covered. Surface defects on this side are ignored and cannot be detected in the existing inspection process. In particular, for newly hidden defects such as scratches, dirt, and abrasions caused by continuous friction between the bottom side and the conveyor belt, dust on the belt surface, and foreign objects adhering to the channel during long-distance side-standing transport, this invention can achieve comprehensive and stable online detection, effectively preventing cigarette packs with such hidden bottom defects from flowing into downstream processes, and fundamentally improving the level of cigarette pack appearance quality control.

[0033] 3. This invention uses a photoelectric switch to trigger an industrial intelligent camera to take pictures when the cigarette pack is in position. The light path of the photoelectric switch is perpendicular to the cigarette pack conveying direction and spans the conveying channel. When a flat cigarette pack passes by, it accurately blocks the light path, generating a stable trigger signal. This ensures that every cigarette pack passing through the posture conversion station can be reliably imaged, avoiding missed or false images. At the same time, the controller achieves electrical isolation connection with the original packaging machine control system through an optocoupler, effectively isolating external electrical interference and ensuring the stability and reliability of signal transmission. Furthermore, it eliminates the need for hardware modifications or changes to the control logic of the original control system, enabling safe, non-destructive, and rapid integration of the detection device with the existing production equipment, reducing the difficulty of equipment adaptation and the risk of modification.

[0034] 4. This invention utilizes adjustable photoelectric switch mounting brackets and camera mounting brackets. The photoelectric switch mounting bracket has a horizontal elongated hole on its base plate and a vertical elongated hole on its vertical plate. The camera mounting bracket has a horizontal adjustment hole on its base and an arc-shaped adjustment hole on its camera mounting plate. This allows the position and angle of the photoelectric switch and industrial intelligent camera to be flexibly adjusted according to the installation space of different machine models and the detection requirements of different cigarette pack specifications. This design is compatible with mainstream packaging machines such as GDX1 and GDX2, as well as the production needs of various specifications of cigarette packs, including regular and slim cigarette packs. It eliminates the need for customized brackets for different specifications, significantly improving the versatility and applicability of the device, and reducing equipment modification costs and maintenance complexity.

[0035] 5. This invention, through the interaction of the horizontal adjustment hole on the base and the arc-shaped adjustment hole on the camera mounting plate, enables comprehensive multi-dimensional adjustment of the industrial intelligent camera in terms of front-back, up-down, and left-right directions. This ensures that the lens center is precisely aligned with the center area of ​​the exposed bottom side of cigarette packs of different sizes, guaranteeing complete and clear imaging and stable and reliable detection. The arc-shaped adjustment hole incorporates both vertical and horizontal displacement components during movement, making the adjustment more aligned with the visual inspection requirements. Furthermore, the overall structure is compact and easy to operate, making it particularly suitable for installation scenarios with limited space at the downstream equipment entrance, significantly reducing the difficulty of on-site installation and debugging. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1a This is a schematic diagram showing the positional relationship between packaging machines, cigarette pack appearance visual inspection devices, and downstream equipment in existing technologies.

[0038] Figure 1b This is a schematic diagram of a prior art visual inspection device for cigarette packs inspecting five sides of a cigarette pack.

[0039] Figure 2 This is a system architecture diagram of the detection device of the present invention;

[0040] Figure 3 This is a system principle flowchart of the detection device of the present invention;

[0041] Figure 4a-1 This is a top view of the photoelectric switch mounting bracket in this invention.

[0042] Figure 4a-2 This is a schematic diagram of the left-side structure of the photoelectric switch mounting bracket in this invention;

[0043] Figure 4b-1 This is a top view of the camera mounting bracket in this invention.

[0044] Figure 4b-2 This is a schematic diagram of the left-side structure of the camera mounting bracket in this invention;

[0045] Figure 4c This is a schematic diagram of the overall installation position of the detection device of the present invention;

[0046] The markings in the diagram are: 1. Chamfering device; 2. Conveying channel; 3. Industrial intelligent camera; 4. Cigarette pack positioning photoelectric switch; 5. Base plate (photoelectric switch mounting bracket); 6. Vertical plate (photoelectric switch mounting bracket); 7. Horizontal elongated hole; 8. Fastening screw (for photoelectric switch bracket); 9. Vertical elongated hole; 10. Base (camera mounting bracket); 11. Camera fixing plate; 12. Horizontal adjustment hole; 13. Fastening screw (for camera bracket); 14. Arc-shaped adjustment hole. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] First, combined Figure 1a and Figure 1b The existing tobacco package conveying and five-sided detection schemes are described. For example... Figure 1a As shown, the cigarette packs produced by the packaging machine are conveyed to downstream equipment via conveyor belt 2. A visual inspection device 3 for the appearance of the cigarette packs is installed on the conveyor belt. Figure 1b As shown, this detection device uses four cameras to photograph the front, back, top and bottom sides, and top and bottom sides of the side-standing cigarette pack 5, respectively, to identify appearance defects on five sides. However, the bottom side of the cigarette pack 5, which contacts the belt 6 (the sixth side of the cigarette pack), cannot be photographed and detected because it is always obscured by the belt, creating a blind spot. Furthermore, during long-distance transport, the bottom side of the cigarette pack is prone to scratches, dirt, and other new defects due to friction with the belt. Existing chamfering devices are only used for posture conversion and lack detection functionality, resulting in these defects going undetected. This invention is proposed to solve the above-mentioned technical problems.

[0049] Example 1

[0050] Please see Figures 2 to 4cThis invention provides a visual inspection device for defects on the bottom surface of a cigarette pack based on a cigarette pack posture conversion station, including a chamfering device 1, a conveying channel 2, an industrial intelligent camera 3, a photoelectric switch for cigarette pack positioning 4, an optocoupler, and a controller.

[0051] The chamfering device 1 is an existing structure on the existing production line, installed on the conveyor channel 2 between the packaging machine outlet and downstream equipment (such as a transparent paper packaging machine or a carton packaging machine). It is used to smoothly convert the side-standing cigarette packs into a lying position before sending them into the downstream equipment inlet. The conveyor channel area between the output end of the chamfering device 1 and the downstream equipment inlet forms a posture conversion station. At this station, the cigarette packs are lying flat, with their bottom side, which was originally in close contact with the conveyor belt, fully exposed to the outside, providing a natural viewing window for visual inspection.

[0052] The photoelectric switch 4 for cigarette pack arrival and the industrial intelligent camera 3 are sequentially arranged along the cigarette pack conveying direction on the side of the conveying channel 2 at the attitude conversion station. The transmitting and receiving ends of the photoelectric switch 4 for cigarette pack arrival are respectively installed on both sides of the conveying channel 2. Its optical path spans the conveying channel 2 along the width direction of the conveying channel and is perpendicular to the cigarette pack conveying direction, and the optical path is located within the height range of the flat cigarette pack. When the flat cigarette pack passes by, it will accurately block the optical path, generating a stable trigger signal to ensure that each cigarette pack can be reliably detected.

[0053] The industrial intelligent camera 3 is installed on one side of the conveyor channel 2 corresponding to the exposed bottom side of the cigarette pack. Its lens is horizontally positioned and perpendicular to the conveying direction of the cigarette pack, with the lens facing the exposed bottom side of the flat-lying cigarette pack. The industrial intelligent camera 3 integrates an image processing module, which can use template matching or differential image algorithms known in the art to identify defects in the acquired images and determine whether there are scratches, dirt, abrasions, or other defects on the bottom side of the cigarette pack.

[0054] The controller and optocoupler are installed inside the existing packaging machine's electrical cabinet. The controller's signal input terminals are connected to the output terminals of the cigarette pack positioning photoelectric switch 4 and the industrial intelligent camera 3, respectively. The controller's signal output terminals are connected to the signal input terminals of the existing packaging machine control system via the optocoupler. The optocoupler achieves electrical isolation between the controller and the existing packaging machine control system, effectively avoiding signal interference or potential mismatch, and requires no hardware modification or logic alteration to the original control system.

[0055] Furthermore, this embodiment also includes two sets of symmetrically arranged photoelectric switch mounting brackets. Each set of photoelectric switch mounting brackets includes a base plate 5 and a vertical plate 6 that are perpendicularly fixed to each other. The base plate 5 has a transverse elongated hole 7 extending along the cigarette pack conveying direction. Fastening screws 8 are inserted into the transverse elongated hole 7, which can lock the base plate 5 to different positions on the side wall of the conveying channel 2, realizing the position adjustment of the base plate 5 along the cigarette pack conveying direction (i.e., the front-to-back direction). The vertical plate 6 has a vertical elongated hole 9 extending in the vertical direction. The transmitting end and receiving end of the cigarette pack positioning photoelectric switch 4 are respectively mounted on the vertical plates 6 of the photoelectric switch mounting brackets on both sides through the fastening screws 8 inserted into the vertical elongated holes 9 of the corresponding side vertical plates 6, and the installation height can be adjusted by sliding along the vertical elongated holes 9. With the above-mentioned adjustable brackets, the length and height differences of different specifications of cigarette packs in the conveying direction can be flexibly adapted, and the installation space of different models can be adapted at the same time.

[0056] Furthermore, this embodiment also includes a camera mounting bracket. The camera mounting bracket includes a base 10 and a camera fixing plate 11 that are perpendicularly fixed to each other. The base 10 has a lateral adjustment hole 12 extending along the tobacco pack conveying direction. Fastening screws 13 pass through the lateral adjustment hole 12, which can lock the base 10 to different positions on the side wall of the conveying channel 2, thereby realizing the front-to-back position adjustment of the industrial intelligent camera 3 along the tobacco pack conveying direction.

[0057] The camera mounting plate 11 has an arc-shaped adjustment hole 14, and a fastening screw 13 passes through the arc-shaped adjustment hole 14 to fix the industrial intelligent camera 3 to the camera mounting plate 11. The arc-shaped adjustment hole 14 is an arc-shaped groove in a vertical plane. When the fastening screw moves along the arc-shaped groove, the industrial intelligent camera 3 will simultaneously produce vertical and horizontal displacement. That is, while adjusting the camera's installation height, it will also finely adjust the camera's left and right position perpendicular to the conveying direction. At the same time, the camera, as a rigid body, will rotate slightly around the center of the arc, causing the direction of the lens optical axis in the vertical plane to change, thereby achieving angle calibration and ensuring that the lens is accurately aligned with the exposed bottom side of the cigarette pack.

[0058] By combining the horizontal adjustment hole and the arc-shaped adjustment hole on the base, the industrial intelligent camera can be comprehensively adjusted in multiple dimensions (front-back, up-down, left-right) to ensure that the center of the lens can be reliably aligned with the center of the exposed side of the cigarette pack, guaranteeing a complete imaging area and a stable field of view. This arc-shaped groove structure is more compact than multiple independent elongated hole adjustment methods, and the adjustment path better fits the visual alignment requirements, making it particularly suitable for installation environments with limited space at the downstream equipment entrance.

[0059] Furthermore, the controller's signal output terminals include a defect signal output terminal and an alarm signal output terminal. The defect signal output terminal is connected to the control input terminal of the original packaging machine's rejection mechanism via an optocoupler, and is used to output an NG signal when a defective cigarette pack is detected, thereby controlling the original rejection mechanism to perform a rejection action. The alarm signal output terminal is connected to the control input terminal of the original packaging machine's audible and visual alarm module via an optocoupler. When the number of consecutive NG cigarette packs reaches a preset threshold, the controller outputs an alarm signal to trigger an audible and visual alarm, indicating that a batch quality abnormality has occurred on the production line. This facilitates operators in promptly troubleshooting equipment malfunctions or production condition problems, preventing the continuous generation of defective cigarette packs.

[0060] like Figure 4c As shown, a turret device is typically installed at the downstream equipment entrance. This turret device is an existing structure of the downstream equipment and is used to grab the flat cigarette packs and send them into the subsequent packaging process. In this embodiment, the cigarette pack positioning photoelectric switch 4 and the industrial intelligent camera 3 are exemplarily deployed after the turret device, utilizing the stable posture and fixed bottom side orientation of the cigarette pack after being grabbed by the turret for image acquisition. It should be noted that the core of this invention lies in using the posture conversion station downstream of the chamfering device and before the downstream equipment entrance for bottom surface detection. The specific installation position of the detection device (such as before or after the turret device) is not critical, as long as image acquisition is completed after the bottom side of the cigarette pack is fully exposed and before entering the downstream equipment, the purpose of this invention can be achieved. Figure 4c The layout shown is only a preferred embodiment of the present invention. Those skilled in the art can flexibly adjust the placement of the detection device according to the actual installation space and equipment layout.

[0061] Example 2

[0062] This embodiment provides a visual inspection method for defects on the bottom surface of a cigarette pack based on a cigarette pack posture conversion station, which is applied to the inspection device described in Embodiment 1 above.

[0063] Please refer to Figure 3. The method includes the following steps:

[0064] S1. The cigarette pack is output from the packaging machine outlet in a side-standing position and is conveyed to the chamfering device 1 along the conveyor channel 2. The chamfering device 1 smoothly converts the side-standing cigarette pack into a flat position and then sends it out. At this time, the bottom side of the cigarette pack that was originally attached to the conveyor belt is fully exposed to the outside, providing stable visual conditions for visual inspection.

[0065] S2. The cigarette packs in a flat position enter the posture conversion station along the conveyor channel 2. When the cigarette pack blocks the optical path of the cigarette pack positioning photoelectric switch 4, the cigarette pack positioning photoelectric switch 4 sends a trigger signal to the controller to ensure that every passing cigarette pack can be reliably triggered and detected.

[0066] S3. After receiving the trigger signal, the controller immediately sends a photo-taking command to the industrial intelligent camera 3. The industrial intelligent camera 3 takes a photo of the bottom side of the cigarette pack and transmits the acquired image to the built-in image processing module. The industrial intelligent camera 3 has completed multi-dimensional alignment calibration in front-back, up-down, and left-right directions through the cooperation of the horizontal adjustment hole and the arc-shaped adjustment hole of the camera mounting bracket to ensure that the acquired image is complete and clear.

[0067] S4. The image processing module performs defect identification on the image, determines whether there are bottom surface defects (such as scratches, dirt, scratches, etc.), and sends the judgment result signal (OK or NG) to the controller.

[0068] S5. If the judgment result is qualified, the controller does not output an action signal, and the cigarette pack enters the downstream equipment normally; if the judgment result is defective (NG signal), the controller sends a defect rejection signal to the original packaging machine control system through the defect signal output terminal via an optocoupler. At the same time, the controller communicates with the human-machine interface of the original packaging machine for parameter setting and status viewing.

[0069] S6. The original packaging machine control system calculates the delay time based on the defect rejection signal, combined with the cigarette pack conveying distance and conveying speed (delay time). Where L is the conveying distance from the inspection station to the rejection station, and V is the conveying speed of the cigarette pack. When the defective cigarette pack is conveyed to the rejection station, the original machine's rejection solenoid valve is activated, thereby driving the rejection mechanism to accurately reject the defective cigarette pack.

[0070] S7. The controller counts the number of consecutive NG (non-performing) cigarette packs in real time. When the number of consecutive NG cigarette packs reaches a preset threshold (e.g., an integer between 3 and 10), the controller sends an alarm signal to the existing packaging machine control system via an optocoupler through the alarm signal output terminal, triggering the audible and visual alarm module. This alerts the production line to a batch quality abnormality, facilitating timely troubleshooting of equipment malfunctions or production conditions by operators and preventing the continuous production of defective cigarette packs. This mechanism avoids frequent alarms caused by occasional false alarms while ensuring timely warnings for batch quality issues.

[0071] Preferably, the defect identification in step S4 can employ image processing algorithms known in the art. Specifically, the image processing module compares the acquired bottom and side images of the cigarette pack with a pre-stored standard template image pixel by pixel, calculating the area and grayscale difference of the difference region. When the area of ​​the difference region exceeds a preset area threshold, or the grayscale difference exceeds a preset grayscale threshold, a defect is determined to exist (outputting an NG signal). This algorithm has high sensitivity for identifying surface defects such as scratches and dirt, and the dual threshold judgment can effectively reduce the false detection rate caused by factors such as ambient light fluctuations and cigarette pack surface reflection. Those skilled in the art will understand that the above pixel comparison, difference region extraction, and dual threshold judgment are all conventional techniques in the field of image processing, and the specific implementation method can be configured according to the actual detection accuracy requirements.

[0072] Preferably, the delay time calculation in step S6 ensures synchronization between the rejection action and the cigarette pack conveying rhythm. The original packaging machine control system calculates the delay time based on the conveying distance and speed of the cigarette pack from the posture conversion station to the rejection station. When the delay time is reached, it controls the rejection mechanism to act, ensuring that defective cigarette packs are accurately rejected when they arrive at the rejection station, avoiding rejection failure due to time deviation.

[0073] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, alterations, additions or substitutions made by those skilled in the art within the scope of the present invention should be protected by the present invention.

Claims

1. A visual inspection device for bottom surface defects of cigarette packs based on a cigarette pack posture conversion station, comprising a chamfering device (1), wherein the chamfering device (1) is disposed on the conveying channel (2) between the packaging machine outlet and the downstream equipment, for converting the cigarette pack in a side-standing posture into a flat posture and sending it into the downstream equipment inlet, the conveying channel area between the output end of the chamfering device (1) and the downstream equipment inlet forms a posture conversion station, wherein the cigarette pack at this station is in a flat posture, and its bottom side originally in contact with the conveyor belt is completely exposed outwards, characterized in that, Also includes: Industrial intelligent camera (3), cigarette pack positioning photoelectric switch (4), optocoupler and controller; The photoelectric switch (4) for the cigarette pack in place and the industrial intelligent camera (3) are arranged sequentially along the cigarette pack conveying direction on the side of the conveying channel (2) at the attitude conversion station; The transmitting end and receiving end of the photoelectric switch (4) for cigarette pack positioning are respectively installed on both sides of the conveying channel (2), and its optical path spans the conveying channel (2) along the width direction of the conveying channel and is perpendicular to the cigarette pack conveying direction; The industrial intelligent camera (3) is installed on one side of the conveying channel (2) corresponding to the exposed bottom side of the cigarette pack. Its lens center is horizontally arranged and perpendicular to the conveying direction of the cigarette pack. The lens faces the exposed bottom side of the flat cigarette pack. The controller and optocoupler are installed inside the original packaging machine cabinet. The signal input terminal of the controller is connected to the output terminal of the cigarette pack positioning photoelectric switch (4) and the output terminal of the industrial intelligent camera (3), respectively. The signal output terminal of the controller is connected to the signal input terminal of the original packaging machine control system through the optocoupler.

2. The visual inspection device for defects on the bottom surface of a cigarette pack based on a cigarette pack posture conversion station as described in claim 1, characterized in that, It also includes two sets of symmetrically arranged photoelectric switch mounting brackets, each set of photoelectric switch mounting brackets including a base plate (5) and a vertical plate (6) that are perpendicularly fixed to each other. The base plate (5) has a transverse elongated hole (7) extending along the tobacco pack conveying direction. Fastening screws (8) are inserted into the transverse elongated hole (7) to lock the base plate (5) at different positions on the side wall of the conveying channel (2) and realize the position adjustment of the base plate (5) along the tobacco pack conveying direction. The vertical plate (6) has a vertical elongated hole (9) extending in the vertical direction. The transmitting and receiving ends of the photoelectric switch (4) for cigarette pack positioning are respectively installed on the vertical plates (6) of the photoelectric switch mounting brackets on both sides through fastening screws (8) that pass through the vertical elongated holes (9) of the corresponding side vertical plates (6), and the installation height can be adjusted by sliding along the vertical elongated holes (9).

3. The visual inspection device for defects on the bottom surface of a cigarette pack based on a cigarette pack posture conversion station as described in claim 1, characterized in that, It also includes a camera mounting bracket, which includes a base (10) and a camera mounting plate (11) that are perpendicularly fixed to each other. The base (10) has a transverse adjustment hole (12) extending along the cigarette pack conveying direction. The fastening screw (13) is inserted into the transverse adjustment hole (12) so that the base (10) can be locked to different positions on the side wall of the conveying channel (2) to realize the position adjustment of the industrial intelligent camera (3) along the cigarette pack conveying direction. The camera mounting plate (11) has an arc-shaped adjustment hole (14), and the fastening screw (13) is inserted into the arc-shaped adjustment hole (14) to lock the industrial intelligent camera (3) at different angle positions on the camera mounting plate (11), thereby realizing the angle calibration of the optical axis of the camera lens and ensuring that the lens is accurately aligned with the exposed side of the cigarette pack.

4. The visual inspection device for defects on the bottom surface of a cigarette pack based on a cigarette pack posture conversion station according to claim 1, characterized in that, The controller's signal output terminals include a defect signal output terminal and an alarm signal output terminal; the defect signal output terminal is connected to the control input terminal of the original packaging machine's rejection mechanism via an optocoupler; the alarm signal output terminal is connected to the control input terminal of the original packaging machine's audible and visual alarm module via an optocoupler.

5. A visual inspection method for defects on the bottom surface of a cigarette pack based on a cigarette pack posture conversion station, applied to the inspection device described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1. The cigarette pack enters the chamfering device (1) in a side-standing position. After being guided by the chamfering device (1), it is converted to a flat position for output, with the bottom side of the cigarette pack that was originally attached to the conveyor belt exposed to the outside. S2. The cigarette pack in a flat position enters the posture conversion station along the conveying channel (2), blocking the light path of the cigarette pack positioning photoelectric switch (4). The cigarette pack positioning photoelectric switch (4) sends a trigger signal to the controller. S3. After receiving the trigger signal, the controller sends a photo-taking command to the industrial intelligent camera (3). The industrial intelligent camera (3) takes a photo of the bottom side of the cigarette pack and outputs the image. S4. The image processing module built into the industrial intelligent camera (3) performs defect identification on the image, determines whether there are bottom surface defects, and sends the judgment result signal to the controller. S5. If the judgment result is qualified, the controller does not output an action signal, and the cigarette pack enters the downstream equipment normally; if the judgment result is defective, the controller sends a defect rejection signal to the original packaging machine control system through the defect signal output terminal via the optocoupler; the controller communicates with the human-machine interface of the original packaging machine for parameter setting and status viewing. S6. The original packaging machine control system calculates the delay time based on the defect rejection signal and the cigarette pack conveying distance and speed. When the defective cigarette pack is conveyed to the rejection station, it controls the original rejection solenoid valve to act, thereby driving the rejection mechanism to reject the defective cigarette pack. S7. The controller counts the number of consecutive defective cigarette packs in real time. When the number of consecutive defective cigarette packs reaches the preset threshold, the controller sends an alarm signal to the original packaging machine control system through the alarm signal output terminal via the optocoupler, triggering the audible and visual alarm module.

6. The visual inspection method for defects on the bottom surface of a cigarette pack based on a cigarette pack posture conversion station according to claim 5, characterized in that, In step S4, the image processing module compares the collected image of the bottom side of the cigarette pack with the pre-stored standard template image pixel by pixel, calculates the area and grayscale difference of the difference region, and determines that there is a defect when the area of ​​the difference region exceeds the preset area threshold or the grayscale difference exceeds the preset grayscale threshold.

7. The visual inspection method for defects on the bottom surface of a cigarette pack based on a cigarette pack posture conversion station according to claim 5, characterized in that, In step S6, the original packaging machine control system calculates the delay time based on the conveying distance and speed of the cigarette pack from the posture conversion station to the rejection station, and controls the rejection mechanism to move when the delay time is reached.

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