Appearance Quality Control System for Both Front and Back Sides of Cigarette Packs and Its Control Method

Abstract

The present invention discloses an appearance quality control system for both the front and back sides of a cigarette pack and its control method, which includes a first channel, a second channel, a third channel, a turret, a lifting device, a conveying device, a rejection device, a first camera, a second camera, and a processor. The rejection device rejects unqualified cigarette packs from the conveying device; the first camera is used to collect images of the cigarette packs conveyed through the first channel; the second camera is used to collect images of the cigarette packs conveyed through the second channel; the processor is provided with an image segmentation module, a color comparison module, and a shift register module to identify defects of the cigarette packs. The present invention samples at specific positions of the cigarette packs before and after the packaging transparent paper, automatically judges the quality of the cigarette packs through the recognition and comparison of the image colors, can quickly reject unqualified cigarette packs without stopping the machine, eliminates the inflow of unqualified products into the finished products to the greatest extent, saves auxiliary materials, ensures product quality, and saves the input of human resources for rework.

Description

Technical Field

[0001] The present invention relates to the technical field of tobacco equipment, and specifically, to an appearance quality control system and a control method for both the front and back sides of cigarette packets. Background Art

[0002] The 753 transparent paper small packet machine is a device for wrapping the outer packaging transparent paper around small box cigarette packets. During actual production, it has been repeatedly found that cigarette packets with the sealing label corners folded back, cigarette packets with the sealing label severely skewed, cigarette packets without a drawstring, and cigarette packets with the drawstring offset (offset less than 20 mm) and severely offset (offset greater than 20 mm) flow into the downstream machine, resulting in quality accidents.

[0003] Due to reasons such as the quality of the sealing label itself or malfunctions of the glue applicator, poor glue spraying effect, improper adjustment of the conveying channel, glue accumulation in the conveying channel, burrs in the conveying channel, and wear and warping of the conveying belt, any one of these reasons will cause the problem of the sealing label corners being folded back, and it is not easy for the operator to detect, so it is very easy for cigarette packets with the sealing label corners folded back to flow into the downstream machine, resulting in quality accidents.

[0004] There is a set of appearance quality control system (FPA) for small box cigarette packets in the upstream machine, but it only detects the bottom, top, front, and left sides of the cigarette packets without the outer packaging transparent paper, and does not detect the right side and the back side of the cigarette packets. However, the sealing label on the back of the cigarette packet may occasionally be skewed and not be rejected, resulting in quality accidents where cigarette packets with the sealing label on the back severely skewed flow into the downstream machine.

[0005] The 753 small box transparent paper packaging machine has a drawstring detector. Due to the limitations of its detection principle, it is difficult to adjust. Coupled with reasons such as difficult dust cleaning of the detector and the reflector and fluctuations in the quality of raw materials, there will occasionally be a problem that small box drawstring offsets are not rejected. After the transparent paper with the drawstring passes through the drawstring detector, it still has to go through processes such as conveying, cutting, and re-conveying before being wrapped around the small box cigarette packet. During this process, the loss of the drawstring that occurs cannot be detected by the original control system, and this type of cigarette packet cannot be rejected by the original control system, resulting in quality accidents where cigarette packets without a drawstring flow into the downstream machine. Due to the operator adding the cigarette packet in the wrong direction when manually adding cigarette packets, or due to the reasons of the cigarette packet conveying and storage device in the upstream machine, the cigarette packet is flipped, resulting in the cigarette packet being in the wrong position (inverted) when entering the transparent paper packaging position, resulting in quality accidents where cigarette packets with the drawstring severely offset (offset greater than 20 mm) flow into the downstream machine.

[0006] The above reasons cause appearance quality accidents of cigarette packets. Once they flow into the finished products, they will seriously affect the brand image. In order to eliminate this negative impact, it is necessary to rework the packaged products, which not only wastes a large amount of human resources but also wastes auxiliary materials.

[0007] Content of the Invention Patent

[0008] To solve the above technical problems, the present invention provides an appearance quality control system and a control method for both front and back sides of a cigarette pack, sampling at specific positions of the cigarette pack before and after the wrapping transparent paper, automatically judging the quality of the cigarette pack through the recognition and comparison of image colors, and quickly removing unqualified cigarette packs without stopping the machine.

[0009] The present invention adopts the following technical solutions to solve the technical problems:

[0010] An appearance quality control system for both front and back sides of a cigarette pack includes: a first channel, a second channel, a third channel, a turret, a lifting device, a conveying device, a rejection device, a first camera, a second camera, and a processor; wherein,

[0011] The turret is arranged between the first channel and the second channel to flip the cigarette pack by 180°;

[0012] The lifting device is arranged between the second channel and the conveying device to lift the cigarette pack from the second channel to the conveying device;

[0013] The conveying device is arranged between the lifting device and the third channel;

[0014] The rejection device is arranged downstream of the second channel and is used to remove unqualified cigarette packs according to the instructions of the processor;

[0015] The first camera is arranged above the first channel to take pictures of the cigarette packs conveyed through the first channel for collecting images of the cigarette packs conveyed through the first channel;

[0016] The second camera is arranged above the second channel to take pictures of the cigarette packs conveyed through the second channel for collecting images of the cigarette packs conveyed through the second channel;

[0017] The first camera and the second camera are electrically connected to the processor and transmit the cigarette pack images to the processor;

[0018] The processor is provided with an image segmentation module, a color comparison module, and a shift register module;

[0019] The image segmentation module is used to segment each area of the cigarette pack image;

[0020] The color comparison module is used to compare and analyze the segmented images to identify unqualified cigarette packs;

[0021] The shift register module is used to mark unqualified cigarette packs.

[0022] Furthermore, the first channel is one channel or multiple channels arranged side by side; preferably, the number of the first channels is two, and two groups of cigarette packs are conveyed simultaneously to improve production efficiency;

[0023] The number of the second channel, the third channel, the first camera, the second camera and the rejection device is the same as that of the first channel, so that the first camera and the second camera can take pictures of the cigarette packs conveyed through each first channel and each second channel, and the rejection device can reject the unqualified cigarette packs conveyed through the corresponding channels respectively.

[0024] Furthermore, the system further includes a display and an alarm, which are electrically connected to the processor. The pictures taken by the first camera and the second camera are transmitted to the display by the processor in real time and displayed on the display for the operator to view. The pictures stored in the processor can also be retrieved and viewed through the display, and the alarm information can also be displayed on the display.

[0025] Furthermore, a method for controlling the appearance quality of the front and back sides of a cigarette pack, the control method uses the control system, and specifically includes the following steps:

[0026] S1. The first camera collects the front image of the cigarette pack and transmits it to the processor;

[0027] S2. The image segmentation module segments the front image of the cigarette pack;

[0028] S3. The second camera collects the back image of the cigarette pack and transmits it to the processor;

[0029] S4. The image segmentation module segments the back image of the cigarette pack;

[0030] S5. Sample the segmented image through a sampling frame, and perform comparison and analysis on the image within the sampling frame through a color comparison module to identify the unqualified cigarette packs;

[0031] S6. The shift register module marks the unqualified cigarette packs and controls the rejection device to reject the unqualified cigarette packs.

[0032] Furthermore, the image segmentation module divides the front image of the cigarette pack into at least a seal part and a typical trademark part; divides the back image of the cigarette pack into at least a pull strip part, a seal part and a typical trademark part, and specifically identifies the defects generated on the seals and pull strips of the cigarette packs.

[0033] Furthermore, the sampling parts of the sampling frame include all corners of the seal, at least one side edge of the seal and the pull strip.

[0034] Furthermore, the sampling parts of the sampling frame include two opposite side edges of the seal, or include the entire seal, or include some patterns inside the seal; there are at least two sampling frames at the pull strip to improve the detection accuracy.

[0035] Further, the number, size, and position of the divided blocks and sampling frames can be adjusted according to the detection part and detection accuracy to make the detection results more comprehensive and accurate.

[0036] Further, the color comparison module performs comparison and analysis on the image within the sampling frame, including comparing and analyzing the image within the sampling frame with the sample image.

[0037] Further, the color comparison module performs comparison and analysis on the image within the sampling frame, including comparing and analyzing the images of the sampling frames on the front and back sides of the cigarette pack.

[0038] Further, the control method further includes the following steps:

[0039] S1. When three consecutive cigarette packs have the same defect, the processor sends an alarm message to be displayed on the monitor.

[0040] S2. When five consecutive cigarette packs have the same defect, the processor sends a control signal to stop the equipment and displays the reason for the stop on the monitor.

[0041] The beneficial effects of the appearance quality control system and its control method for the front and back sides of the cigarette pack of the present invention are as follows:

[0042] 1. By setting sampling frames at specific positions of the cigarette packs before and after the packaging transparent paper, such as the corners of the seal, the edge of the seal, and the pull strip, etc., and through the recognition of the image color, the unqualified cigarette packs are removed, and the inflow of unqualified products into the finished products is eliminated to the greatest extent.

[0043] 2. The control system automatically judges the quality of the cigarette pack and automatically classifies and disposes it, and can quickly remove the unqualified cigarette packs without stopping the machine.

[0044] 3. Avoid the inflow of unqualified cigarette packs into downstream equipment, which not only saves auxiliary materials, but also ensures product quality, and also saves the input of human resources for rework. Description of the Drawings

[0045] Figure 1 It is a schematic structural diagram of the appearance quality control system for the front and back sides of the cigarette pack of the present invention.

[0046] Figure 2 It is a sampling schematic diagram of a normal cigarette pack at the corner of the seal of the present invention.

[0047] Figure 3 It is a sampling schematic diagram of a cigarette pack with a folded corner at the corner of the seal of the present invention.

[0048] Figure 4 It is a sampling schematic diagram of a normal cigarette pack at the edge of the seal of the present invention.

[0049] Figure 5Schematic diagram of sampling a cigarette pack with a skewed seal for the present invention.

[0050] Figure 6 Schematic diagram of sampling a cigarette pack with a normal drawstring for the present invention.

[0051] Figure 7 Schematic diagram of sampling a cigarette pack with a displaced drawstring for the present invention.

[0052] In the figure: 1 - First channel; 2 - Second channel; 3 - Third channel; 4 - Turret; 5 - Lifting device; 6 - Conveyor device; 7 - Rejection device; 8 - First camera; 9 - Second camera; 10 - Recycling bin; 11 - Processor; 12 - Solenoid valve; 13, Display; 14 - Alarm; 15 - Air pipe; 16 - Connecting wire; 17 - Cigarette pack; 18 - Seal part; 19 - Typical trademark part; 20 - Drawstring part; 21 - Sampling frame. Detailed implementation manners

[0053] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0054] In the description of the present invention, it should be understood that terms such as "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0055] The present invention provides a quality control system for the front and back appearances of cigarette packs, as Figure 1As shown in the figure, it includes a first channel 1, a second channel 2, a third channel 3, a turret 4, a lifting device 5, a conveying device 6, a rejection device 7, a first camera 8, a second camera 9 and a processor 11. Among them, the turret 4 is arranged between the first channel 1 and the second channel 2 to turn the cigarette pack 17 by 180°. The lifting device 5 is arranged between the second channel 2 and the conveying device 6 to lift the cigarette pack 17 from the second channel 2 to the conveying device 6, and the conveying device 6 is arranged between the lifting device 5 and the third channel 3. The rejection device 7 is arranged downstream of the second channel. Preferably, the rejection device 7 is arranged at the rear side of the conveying device 6 and is used to reject the unqualified cigarette packs 17 from the conveying device 6 according to the instructions of the processor 11. The first camera 8 is arranged above the first channel 1 to take pictures of the cigarette packs 17 conveyed through the first channel 1 for collecting images of the cigarette packs 17 conveyed through the first channel 1. The second camera 9 is arranged above the second channel 2 to take pictures of the cigarette packs 17 conveyed through the second channel 2 for collecting images of the cigarette packs 17 conveyed through the second channel 2. It should be noted that the first camera 8 is arranged above the first channel 1 and the second camera 9 is arranged above the second channel 2, which not only includes directly above the channels but also includes the side above the channels, as long as it is a position where each camera can clearly and conveniently collect images of the cigarette packs 17. The first camera 8 and the second camera 9 are electrically connected to the processor 11 and transmit images of the cigarette packs 17 to the processor 11. The processor 11 is provided with an image segmentation module, a color comparison module and a shift register module. The image segmentation module is used to segment each area of the image of the cigarette pack 17; the color comparison module is used to compare and analyze the segmented images to identify the unqualified cigarette packs 17; the shift register module is used to mark the unqualified cigarette packs 17 so that when the unqualified cigarette packs 17 are conveyed to the position of the rejection device 7, the processor rejects the unqualified cigarette packs 17.

[0056] When the cigarette pack 17 is being produced and packed, the cigarette pack 17 conveyed by the upstream machine enters the first channel 1 and is conveyed forward. At this time, the front side of the cigarette pack 17 is facing up. When the cigarette pack 17 is conveyed to the effective photographing range of the first camera 8, the first camera 8 takes a photo of the front side of the cigarette pack 17 and transmits the taken photo to the processor 11. The cigarette pack 17 continues to be conveyed forward and enters the die box of the turret 4. When the transparent paper and the draw tape are wrapped onto the cigarette pack 17 when the cigarette pack 17 enters the turret 4, and after the turret 4 flips the cigarette pack 17 by 180°, it is conveyed forward. At this time, the back side of the cigarette pack 17 is facing up. When the cigarette pack 17 is conveyed to the effective photographing range of the second camera 9, the second camera 9 takes a photo of the back side of the cigarette pack 17 and transmits the taken photo to the processor 11. The processor 11 is provided with an image segmentation module and a color comparison module. By comparing and analyzing the collected images, the unqualified cigarette packs 17 are identified and marked through the shift register module in the processor 11. All cigarette packs 17 need to be lifted by the lifting device 5 and then conveyed by the conveying device 6. The cigarette packs 17 determined to be qualified are directly conveyed to the third channel 3 and then enter the downstream machine to enter the next packaging process. When the cigarette packs 17 determined to be unqualified are conveyed to the position of the rejection device 7, the unqualified cigarette packs 17 are rejected by the rejection device 7.

[0057] The operation of the rejection device 7 is controlled by the solenoid valve 12. The solenoid valve 12 is arranged on the air pipe 15 of the compressed air. The air pipe 15 is connected to the rejection device 7. The solenoid valve 12 is electrically connected to the processor 11 through the connection line 16. When the processor 11 identifies the unqualified cigarette pack 17 and the unqualified cigarette pack 17 is conveyed to the position of the rejection device 7, the processor 11 sends a rejection signal to the solenoid valve 12. The solenoid valve 12 changes its position, enabling the compressed air to pass through the air pipe 15 to control the rejection device 7 to perform the rejection operation. After the rejection operation is completed, the solenoid valve 12 returns to its original position, and the flow direction of the compressed air changes, controlling the rejection device 7 to return to its original position through the compressed air. A recycling box 10 is also arranged below the rejection device 7 for recycling the rejected unqualified cigarette packs 17. The operators can further judge and process the rejected cigarette packs 17, which can avoid quality accidents where cigarette packs 17 with defects such as reverse folding of the seal corner, skew of the seal, and missing draw tape flow into the downstream machine.

[0058] To improve production efficiency, multiple channels can be used to convey cigarette packs 17 simultaneously. The first channel 1 can be set as multiple side-by-side channels. Preferably, the number of the first channels 1 is two, and two groups of cigarette packs 17 are conveyed simultaneously to improve production efficiency. The numbers of the second channel 2, the third channel 3, the first camera 8, and the second camera 9 are consistent with the number of the first channels 1, so that the first camera 8 and the second camera 9 can take pictures of the cigarette packs 17 conveyed through each first channel 1 and each second channel 2. Correspondingly, the number of the rejection devices 7 is also consistent with the number of the first channels 1, so that the rejection devices 7 can respectively reject the unqualified cigarette packs 17 conveyed through the corresponding channels.

[0059] The system further includes a display 13 and an alarm 14, and the display 13 and the alarm 14 are electrically connected to the processor 11 through a connecting wire 16. The photos taken by the camera are transmitted to the display 13 in real time by the processor 11 and displayed on the display 13 for the operator to view. The processor 11 is also provided with a storage module for storing the photos transmitted to the processor 11, and the photos stored in the processor 11 can also be retrieved and viewed through the display 13. Alarm information can also be displayed on the display 13. When there are multiple cigarette packs 17 with the same defect continuously, the alarm 14 emits an alarm signal such as light or sound and displays the alarm information on the display 13 to remind the operator.

[0060] The present invention also provides a method for controlling the appearance quality of the front and back sides of a cigarette pack. The control method uses the appearance quality control system for the front and back sides of the cigarette pack to perform quality control, which specifically includes the following steps:

[0061] S1. The first camera 8 collects the front image of the cigarette pack 17 and transmits it to the processor 11;

[0062] S2. The image segmentation module segments the front image of the cigarette pack 17;

[0063] S3. The second camera 9 collects the back image of the cigarette pack 17 and transmits it to the processor 11;

[0064] S4. The image segmentation module segments the back image of the cigarette pack 17;

[0065] S5. Sample the segmented image through the sampling frame 21, and perform comparison and analysis on the image within the sampling frame 21 through the color comparison module to identify the unqualified cigarette packs 17;

[0066] S6. The shift register module marks the unqualified cigarette packs 17 and controls the rejection device 7 to reject the unqualified cigarette packs 17.

[0067] The first camera 8 takes a picture of the front of the cigarette pack 17 and transmits the picture of the front of the cigarette pack 17 to the processor 11. The processor 11 divides the front image of the cigarette pack 17 into blocks and compares each block with the samples in the processor 11. Compare the difference values of all the comparison results of the front image blocks with the threshold value. If the difference values of all the comparison results of the front image blocks do not exceed the threshold value, it is determined that the cigarette pack 17 is a qualified product on the front side; if the difference value of any one block comparison result exceeds the threshold value, it is determined that the cigarette pack 17 is a non-conforming product, and the cause of the defect is recorded.

[0068] When the cigarette pack 17 is flipped 180° by the turret 4, the back of the cigarette pack 17 faces up. The second camera 9 takes a picture of the back of the cigarette pack 17 and transmits the picture of the back of the cigarette pack 17 to the processor 11. Similarly, the processor 11 divides the back image of the cigarette pack 17 into blocks and compares each block with the samples in the processor 11. Compare the difference values of all the comparison results of the back image blocks with the threshold value. If the difference values of all the comparison results of the back image blocks do not exceed the threshold value, it is determined that the cigarette pack 17 is a qualified product on the back side; if the difference value of any one block comparison result exceeds the threshold value, it is determined that the cigarette pack 17 is a non-conforming product, and the cause of the defect is recorded.

[0069] The cigarette pack 17 that is determined to be a qualified product on both the front and back sides is determined to be a qualified product. The qualified cigarette pack 17 is directly conveyed to the third channel 3 by the conveying device 6. The non-conforming cigarette pack 17 continues to be conveyed forward after being marked by the shift register. When it reaches the position of the rejection device 7, the processor 11 controls the solenoid valve 12 to change positions and activates the rejection device 7 to reject the non-conforming cigarette pack 17.

[0070] The cigarette pack 17 conveyed by the upstream machine first takes a front picture by the first camera 8, and then takes a back picture by the second camera 9. The processor 11 needs to compare and identify both the front and back sides of the cigarette pack 17. Only the cigarette pack 17 with all the comparison results on both the front and back sides being qualified can be determined to be a qualified product and is directly conveyed to the third channel 3 by the conveying device 6 and enters the downstream machine. As long as any one of the comparison results of the cigarette pack 17 is unqualified, it is determined to be a non-conforming product and needs to be rejected to prevent it from flowing into the downstream machine.

[0071] The steps of the processor 11 for determining various quality defects of the cigarette pack 17 are specifically as follows:

[0072] S1. Divide the front image of the cigarette pack 17 taken by the first camera 8 into blocks, at least into the seal part 18 and the typical trademark part 19;

[0073] S2. Identify the cigarette pack 17 with the front seal corner folded back:

[0074] The processor 11 samples the two corners of the front seal of the cigarette pack 17 with the sampling frame 21, compares the color of the selected image in each sampling frame 21 with the color of the sample image in the processor 11. If there is a difference in the color in at least one sampling frame 21, it is marked as a cigarette pack 17 with the front seal corner folded back;

[0075] S3. Identify the cigarette pack 17 with the front seal of the cigarette pack 17 skewed:

[0076] The processor 11 samples at least one side edge of the front seal of the cigarette pack 17 with the sampling frame 21, compares the color of the selected image in the sampling frame 21 with the color of the sample image in the processor 11. If there is a difference in the color in the sampling frame 21, it is marked as a cigarette pack 17 with the front seal skewed; Preferably, the processor 11 samples both opposite side edges of the front seal of the cigarette pack 17 with the sampling frame 21, compares the color of the selected image in each sampling frame 21 with the color of the sample image in the processor 11. If there is a difference in the color in at least one sampling frame 21, it is marked as a cigarette pack 17 with the front seal skewed;

[0077] S4. Divide the back image of the cigarette pack 17 taken by the second camera 9 into blocks, at least into the pull strip part 20, the seal part 18 and the trademark typical part 19;

[0078] S5. Identify the cigarette pack 17 with the back seal corner of the cigarette pack 17 folded back:

[0079] The processor 11 samples the two corners of the back seal of the cigarette pack 17 with the sampling frame 21, compares the color of the selected image in each sampling frame 21 with the color of the sample image in the processor 11. If there is a difference in the color in at least one sampling frame 21, it is marked as a cigarette pack 17 with the back seal corner folded back;

[0080] S6. Identify the cigarette pack 17 with the back seal of the cigarette pack 17 skewed:

[0081] The processor 11 samples at least one side edge of the back seal of the cigarette pack 17 with the sampling frame 21, compares the color of the selected image in the sampling frame 21 with the color of the sample image in the processor 11. If there is a difference in the color in the sampling frame 21, it is marked as a cigarette pack 17 with the back seal skewed; Preferably, the processor 11 samples both opposite side edges of the back seal of the cigarette pack 17 with the sampling frame 21, compares the color of the selected image in each sampling frame 21 with the color of the sample image in the processor 11. If there is a difference in the color in at least one sampling frame 21, it is marked as a cigarette pack 17 with the back seal skewed;

[0082] S7. Identify the cigarette pack 17 with the small box pull strip offset:

[0083] The processor 11 samples the back of the cigarette pack 17 at the pull strip of the inner carton using the sampling frame 21, and compares the color of the selected image within the sampling frame 21 with the color of the sample image in the processor 11. If there is a color difference within the sampling frame 21, it is marked as a defective cigarette pack 17 with a pull strip defect; preferably, the number of sampling frames 21 at the pull strip of the inner carton is at least two to improve the detection accuracy.

[0084] As Figures 2 - 5 shown, the photo taken by the first camera 8 is the front photo of the cigarette pack 17. At this time, the cigarette pack 17 has not been wrapped with transparent paper and the pull strip. The processor 11 divides the front image of the cigarette pack 17 taken by the first camera 8 into blocks, specifically into the seal part 18 and the typical trademark part 19. When the processor 11 performs defect recognition, it needs to recognize the cigarette packs 17 with the seal corners folded back and the seal skewed.

[0085] For the recognition of the cigarette pack 17 with the seal corners folded back, the image of a normal cigarette pack 17 taken by the first camera 8 is as Figure 2 shown. For sampling the corners of one seal, the part selected by the sampling frame 21 of the processor 11 is the front of the seal, and its color is relatively bright. The image of the cigarette pack 17 with the seal corners folded back taken by the first camera 8 is as Figure 3 shown. The part selected by the sampling frame 21 of the processor 11 is composed of the back of the seal and the front of the trademark paper. The color of the back of the seal is white. Regardless of the color of the front of the trademark paper, the combination of these two colors is significantly different from the color of the front of the seal. Through the color comparison in this sampling frame 21, the cigarette pack 17 with the seal corners folded back can be recognized. Similarly, by sampling the corners of the other seal, the cigarette pack 17 with the front seal folded back can be recognized.

[0086] For the recognition of the cigarette pack 17 with the seal skewed, the image of a normal cigarette pack 17 taken by the first camera 8 is as Figure 4 shown. The sampling frame 21 of the processor 11 simultaneously samples the two opposite side edges of the front seal of the cigarette pack 17. The parts selected by the two sampling frames 21 of the processor 11 are both the front of the seal, and its color is relatively bright. The image of the cigarette pack 17 with the seal skewed taken by the first camera 8 is as Figure 5 shown. For the parts selected by the two sampling frames 21 of the processor 11, most or all of at least one sampling frame 21 is the front of the trademark paper. There is a significant color difference between the trademark paper and the seal. Through the color comparison in this sampling frame 21, the cigarette pack 17 with the front seal skewed can be recognized.

[0087] As Figure 6 and Figure 7As shown in the figure, the photo taken by the second camera 9 is the back photo of the cigarette pack 17. At this time, the cigarette pack 17 has passed through the turret 4, and the transparent paper and the drawstring have been wrapped around the cigarette pack 17. The processor 11 divides the back image of the cigarette pack 17 taken by the second camera 9 into blocks, specifically into the drawstring part 20, the seal part 18, and the typical trademark part 19. When the processor 11 performs defect recognition, it needs to recognize all cigarette packs 17 with drawstring offset, seal corner reverse fold, and seal skew.

[0088] The recognition process of the reverse fold of the seal corner and the skew of the seal on the back of the cigarette pack 17 is the same as that of the reverse fold of the seal corner and the skew of the seal on the front of the cigarette pack 17, and will not be elaborated here one by one.

[0089] For the recognition of the cigarette pack 17 with reverse fold of the seal corner, the setting of the sampling frame 21 needs to include all seal corners, and each seal corner needs to be detected to prevent missed detection.

[0090] The seal patterns on the front and back of the cigarette pack 17 are usually the same. For the recognition of the cigarette pack 17 with reverse fold of the seal corner and skew of the seal, sampling can also be performed at the corresponding positions on the front and back of the cigarette pack 17. When the color comparison module compares and analyzes the images in the sampling frame 21, it compares and analyzes the images of the corresponding sampling frames 21 on the front and back of the selected cigarette pack 17. If there are differences in the images in the sampling frames 21 on the front and back, the cigarette pack 17 is determined to be a defective product. If the images in the sampling frames 21 on the front and back are the same, then the image in any one of the sampling frames 21 is compared with the sample image in the processor 11. If there are differences in the colors in the sampling frame 21, it is marked as a cigarette pack 17 with seal defect.

[0091] For the recognition of the cigarette pack 17 with offset of the drawstring of the small box, the image of the normal cigarette pack 17 taken by the second camera 9 is as Figure 6 shown. The part selected by the sampling frame 21 of the processor 11 is the drawstring, and its color is the color of the drawstring. The image of the cigarette pack 17 with offset of the drawstring of the small box taken by the camera is as Figure 7 shown. Most or all of the part selected by the sampling frame 21 of the processor 11 is the front of the label paper. There is an obvious color difference between the label paper and the drawstring. The cigarette pack 17 with offset of the drawstring of the small box can be identified through the color comparison in this sampling frame 21. To improve the accuracy of recognition, the number of sampling frames 21 at the drawstring of the small box is at least two, distributed at different positions at the same height, to improve the accuracy of detection and prevent the defect from not being recognized when only one sampling frame 21 is used for comparison when the drawstring is obliquely offset.

[0092] For the recognition of the cigarette pack 17 with missing drawstring of the small box, similarly, it can be recognized by the recognition method of the cigarette pack 17 with offset of the drawstring of the small box.

[0093] In addition, when the inner pack transparent paper is loose, the inner pack pull tape will inevitably shift. The inner pack transparent paper loose cigarette pack 17 can also be identified by the identification method of the inner pack pull tape shifted cigarette pack 17.

[0094] When the processor 11 identifies the cigarette pack 17 with the front seal corner folded back and the front seal skewed, it can be carried out simultaneously. When the processor 11 identifies the cigarette pack 17 with the back seal corner folded back, the back seal skewed and the inner pack pull tape shifted, it can also be carried out simultaneously.

[0095] When the processor 11 divides the front photo or back photo of the cigarette pack 17 into blocks, if the number, size and position of the blocks are inappropriate, the parameters of the blocks can be adjusted by the processor 11, and the number, size and position of the blocks can be adjusted according to the detection part. Similarly, when the number, size and position of the sampling frames 21 of the processor 11 are inappropriate, the parameters of the sampling frames 21 can also be adjusted by the processor 11, and the number, size and position of the sampling frames 21 can be adjusted according to the detection part and the detection accuracy, so that the detection result is more comprehensive and accurate. Through adjustment, the sampling part of the sampling frame 21 can include the entire seal, and whether there are defects in the seal can be determined through one comparison. It can also make the sampling part of the sampling frame 21 include not only the seal corners and the seal edges, but also some patterns inside the seal. By comparing some patterns inside the seal, it can be identified whether the seal is damaged.

[0096] The control method further includes the following steps:

[0097] S1. When there are 3 consecutive cigarette packs 17 with the same defect, the processor 11 issues an alarm message and displays it on the display 13;

[0098] S2. When there are 5 consecutive cigarette packs 17 with the same defect, the processor 11 issues a control signal to control the equipment to stop, and displays the reason for the stop on the display 13.

[0099] In order to minimize the flow of non-conforming products into the finished products, when there are 3 consecutive cigarette packs 17 with the same defect, the alarm 14 emits alarm signals such as lights or sounds, and displays the alarm message on the display 13 to remind the operator. When there are 5 consecutive cigarette packs 17 with the same defect, the processor 11 issues a control signal to directly control the equipment to stop, and displays the reason for the stop on the display 13 to remind the operator to troubleshoot.

[0100] This control system can identify defects such as the reverse folding of the seal corner, the skew of the seal, the offset / missing of the small box pull tape, and the loose wrapping paper by sampling and comparing specific positions of the cigarette pack 17 before and after the wrapping transparent paper, and automatically classify and dispose of them. It conveys the qualified products to the downstream machine, automatically rejects the unqualified cigarette packs 17, can quickly reject the unqualified cigarette packs 17 without stopping the machine, and maximally eliminate the inflow of unqualified products into the finished products, improving the product quality. Preventing the unqualified cigarette packs 17 from flowing into the downstream machine not only saves auxiliary materials, but also ensures the product quality and saves the input of human resources for rework.

[0101] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A quality control system for the appearance of both the front and back sides of a cigarette pack, characterized in that, Comprising: A first channel, a second channel, a third channel, a turret, a lifting device, a conveying device, a rejecting device, a first camera, a second camera and a processor; wherein, The turret is arranged between the first channel and the second channel; The lifting device is arranged between the second channel and the conveying device; The conveying device is arranged between the lifting device and the third channel; The rejecting device is arranged downstream of the second channel and is used to reject unqualified cigarette packs according to the instructions of the processor; The first camera is arranged above the first channel and is used to collect images of the cigarette packs conveyed by the first channel; The second camera is arranged above the second channel and is used to collect images of the cigarette packs conveyed by the second channel; The first camera and the second camera are electrically connected to the processor and transmit the cigarette pack images to the processor; The processor is provided with an image block module, a sampling frame, a color comparison module and a shift register module; The image block module is used to block each area of the cigarette pack image; The sampling frame is used to sample the blocked image; the sampling parts of the sampling frame include two corners of the front seal of the cigarette pack, two opposite side edges of the front seal of the cigarette pack, two corners of the back seal of the cigarette pack and two opposite side edges of the back seal of the cigarette pack; The color comparison module is used to first compare and analyze the images of the corresponding sampling frames on the front and back sides of the selected cigarette pack seal. If there are differences in the images within the corresponding sampling frames on the front and back sides, it is determined as an unqualified cigarette pack; if the images within the corresponding sampling frames on the front and back sides are the same, then the image within any sampling frame is selected for comparison and analysis with the sample image in the processor. If there are differences in the colors within the sampling frame, it is determined as an unqualified cigarette pack; The shift register module is used to mark unqualified cigarette packs.

2. The appearance quality control system for the front and back sides of a cigarette pack according to claim 1, characterized in that, The first channel is one channel or multiple channels arranged side by side; the numbers of the second channel, the third channel, the first camera, the second camera and the rejecting device are the same as the number of the first channel.

3. The appearance quality control system for the front and back sides of a cigarette pack according to claim 2, characterized in that, The number of the first channels is two.

4. The appearance quality control system for the front and back sides of a cigarette pack according to claim 1, characterized in that, The system further includes a display and an alarm, and the display and the alarm are electrically connected to the processor.

5. A method for controlling the appearance quality of both the front and back sides of a cigarette pack, characterized in that, The control method uses the control system according to any one of claims 1-4, and specifically includes the following steps: S1. The first camera collects the front image of the cigarette pack and transmits it to the processor; S2. The image block module blocks the front image of the cigarette pack; S3. The second camera collects the back image of the cigarette pack and transmits it to the processor; S4. The image block module blocks the back image of the cigarette pack; S5. Sample the blocked images of the front and back of the cigarette pack through the sampling frame. The sampling parts of the sampling frame include two corners of the front seal of the cigarette pack, two opposite side edges of the front seal of the cigarette pack, two corners of the back seal of the cigarette pack and two opposite side edges of the back seal of the cigarette pack; S6. Compare and analyze the images of the corresponding sampling frames on the front and back sides of the selected cigarette pack seal through the color comparison module. If there are differences in the images within the corresponding sampling frames on the front and back sides, it is determined as an unqualified cigarette pack, and then S8 is executed; if the images within the corresponding sampling frames on the front and back sides are the same, then S7 is executed; S7. Select the image within any sampling frame and compare and analyze it with the sample image in the processor. If there are color differences within the sampling frame, determine it as a defective cigarette pack and execute S8; S8. The shift register module marks the defective cigarette packs and controls the rejection device to reject the defective cigarette packs.

6. The method for controlling the appearance quality of both the front and back sides of a cigarette pack according to claim 5, wherein The image segmentation module divides the front image of the cigarette pack into at least a seal part and a typical trademark part; divides the back image of the cigarette pack into at least a pull - strip part, a seal part, and a typical trademark part.

7. The method for controlling the appearance quality of both the front and back sides of a cigarette pack according to claim 5, characterized in that, The sampling part of the sampling frame includes the pull - strip area. The color comparison module compares and analyzes the color of the selected image within the sampling frame at the pull - strip area with the color of the sample image in the processor. If there are color differences within the sampling frame at the pull - strip area, determine it as a defective cigarette pack.

8. The method for controlling the appearance quality of both the front and back sides of a cigarette pack according to claim 7, characterized in that, There are at least two sampling frames at the pull - strip area.

9. The method for controlling the appearance quality of both the front and back sides of a cigarette pack according to claim 5 or 6, characterized in that, The sampling part of the sampling frame includes the entire seal.

10. The method for controlling the appearance quality of both the front and back sides of a cigarette pack according to claim 5, characterized in that, The number, size, and position of the segmentation and sampling frames can be adjusted.

11. The method for controlling the appearance quality of both the front and back sides of a cigarette pack according to claim 5, characterized in that When the system further includes a display and an alarm, the control method further includes the following steps: S1. When there are 3 consecutive cigarette packs with the same defect, the processor sends an alarm message to be displayed on the display; S2. When there are 5 consecutive cigarette packs with the same defect, the processor sends a control signal to control the equipment to stop and displays the reason for the stop on the display.

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