A method and system for accurately picking up the cigarette gift box tab

Abstract

This invention discloses a method and system for accurately picking up the pull tab of a cigarette gift box. It is used on the production conveyor line of a cigarette gift box packaging machine to automatically pull up the pull tab of the cigarette gift box and extend it to the outer end of the box. An industrial camera captures image signals from the cigarette gift box, processes them to obtain position information, and transmits the processed image signals to the ABB controller via a switch. After receiving the image signals, the ABB controller's main program determines whether the pull tab's position offset is too large. If the offset is small, the main program continues to execute; if the offset is large, an error algorithm subroutine is executed to calculate the offset, followed by an offset pull tab tracking subroutine to read the offset pull tab's movement trajectory, achieving accurate pickup of the pull tab. This significantly reduces the defect rate of cigarette cartons with abnormal pull tabs, reduces or even eliminates cigarette cartons with folded pull tabs from entering the next process, ensures that substandard cigarette cartons are promptly removed, and improves product quality.

Description

Technical Field

[0001] This invention relates to the field of functional application technology of gift box cigarette packaging machines, specifically to a method and system for accurately picking up the cigarette gift box tab. Background Technology

[0002] The YB621D gift box cigarette packaging machine is a non-standard customized packaging machine with a simple and reasonable structure and convenient operation. It mainly performs functions such as filling small packs into gift boxes, sorting cellophane, picking up the tab, sealing and labeling, and packaging the carton with cellophane. Because cigarette gift boxes are handmade products, it is difficult to strictly control the production process standards, resulting in a large number of carton tabs being found to have excessive positional deviations during use. The existing technical solution for the YB621D gift box cigarette packaging machine uses a non-positioning ABB robotic arm to grasp the tab. If the deviation of the tab position exceeds the grasping error range of the ABB robotic arm, the tab cannot be successfully picked up, preventing the next step of folding and causing the carton of cigarettes to be rejected at the subsequent rejection mechanism. In other words, during the tab picking process, due to the deviation in the tab position, the robotic arm cannot guarantee successful picking every time.

[0003] It is evident that the YB621D gift box cigarette packaging machine's use of a non-positioning ABB robotic arm for grasping the cigarette tab is ineffective, resulting in a persistently high defect rate for cigarettes with abnormal tabs. Specifically, if the tab's position deviates too much, the ABB robotic arm fails to grasp it successfully. If defective products with folded tabs are discovered in subsequent production stages, rework is necessary, leading to significant material and manpower waste, impacting both production efficiency and costs. Furthermore, if defective products with folded tabs enter the market, it severely diminishes the consumer experience, damages brand trust, harms the company's reputation, and ultimately affects sales and profitability.

[0004] Frequent issues arise where the cigarette pack tabs do not meet packaging process requirements, such as tearing at the bottom, pressing the bottom, inward folding, outward folding, and misalignment, affecting the quality of cigarette pack packaging. Testing data reveals a high defect rate for abnormal tabs in the current production process. This significantly increases the amount of cigarette packs rejected, severely restricting equipment efficiency and wasting manpower and resources. More importantly, continuous tab pickup failures may result in incomplete removal of defective cigarette packs, which then enter the market. Therefore, inventing a precise cigarette pack tab pickup system that can significantly reduce the defect rate of abnormal tabs is essential. Summary of the Invention

[0005] To address the shortcomings and defects of the existing technology, the inventor provides a new solution: a system and method for accurately picking up the cigarette tab. This solves the problem of excessive tab offset causing ABB robotic arms to fail to pick up cigarettes, thereby significantly reducing the defect rate of cigarette cartons with abnormal tabs. It reduces or even eliminates cigarette cartons with folded tabs from entering the next process, ensuring that substandard cigarette cartons are promptly removed, ultimately achieving the invention's objective of improving product quality. Specifically, this invention is implemented as follows:

[0006] A method for precisely picking up the pull tab of a cigarette gift box, used to automatically pull up the pull tab in a cigarette gift box and pull it to the outside of the gift box on the production conveyor line of a cigarette gift box packaging machine, includes the following steps:

[0007] Step S1: The cigarette gift box is conveyed on the production conveyor line and arrives at the image acquisition station. The industrial camera takes a picture of the cigarette gift box directly below and acquires the image data.

[0008] Step S2: Establish a coordinate system based on the location of the workstation obtained from the image, and determine the standard coordinate information of the qualified pull tongue in the coordinate system;

[0009] Step S3: Perform visual recognition processing on the image data, taking the pull tab inside the cigarette gift box as the recognition object, and determine the current position information of the pull tab in the coordinate system;

[0010] Step S4: Based on the current position information, compare it with the standard coordinate information of the qualified tongue puller, calculate the pose error. If the pose error is greater than the preset value, it is judged as tongue puller offset, and obtain the offset coordinate difference corresponding to the pose error.

[0011] Step S5: When the cigarette gift box arrives at the robotic arm's suction station, the robotic arm is in a standard position. If the positional error does not exceed the preset value, the robotic arm performs standardized actions. If the positional error exceeds the preset value, the robotic arm performs displacement compensation and movement correction based on the offset coordinate difference, and performs subsequent actions such as moving the suction nozzle down, sucking up the tongue, and following it into position.

[0012] Furthermore, step S3 includes: the coordinate system is a three-dimensional coordinate system, and the current position information of the pull tab in the coordinate system includes the horizontal position information and the height position information of the pull tab tip; step S4 includes: based on the height position information of the current pull tab tip and the surface height information of the cigarette gift box, if the height position information is greater than the surface height information of the cigarette gift box and exceeds the height threshold, it is determined that the pull tab is raised too high.

[0013] Furthermore, the image acquisition station has a stereo imaging function, which can obtain the height position information of the tongue tip.

[0014] Furthermore, the height position information of the tongue tip is obtained by processing images acquired by an industrial camera, including the following steps:

[0015] The image data inside the cigarette gift box is obtained, and Gaussian filtering or median filtering is used to filter and reduce noise in the image to avoid the influence of noise on shadow edge detection. The image is then converted into a grayscale image for shadow edge detection.

[0016] By convolving the image, the gradient magnitude and direction of each pixel are calculated, and edge detection is performed by calculating the gradient magnitude of each pixel.

[0017] Gradient thresholding is performed on the shadow edge image, setting a high threshold and a low threshold. Edges with gradients higher than the high threshold are labeled as strong edges, those with gradients lower than the low threshold are labeled as non-edges, and those with gradients higher than the low threshold but lower than the high threshold are labeled as weak edges.

[0018] The shadow intensity is inferred by the shadow edge intensity, and a correspondence is established between the height information of the tongue tip and the shadow intensity based on the machine self-learning algorithm, thereby obtaining the height information of the tongue tip based on image recognition.

[0019] Furthermore, the height position information of the pull tab obtained by the image acquisition station is compared with the difference of the gift box surface. If the difference is greater than the preset value, it is determined that the pull tab is raised too high. When the pull tab is raised too high, the suction nozzle of the robot blows out positive pressure air during the downward movement. After descending to the predetermined height, it stops blowing out positive pressure air and switches to suction negative pressure air to accurately suck up the pull tab.

[0020] Another aspect of the present invention provides a precision pickup system for cigarette gift box tabs, applied on the production conveyor line of a gift box cigarette packaging machine, comprising:

[0021] The image acquisition station, located directly above the production conveyor line, includes a lighting device, an industrial camera, and an adjustable camera mounting bracket; it is used to illuminate and capture images of the top of cigarette gift boxes and send the captured images to the robot controller.

[0022] The robotic arm suction station is located on the production conveyor line, after the image acquisition station. It includes a robotic arm and a suction nozzle. The suction nozzle is located at the end of the robotic arm and is connected to the robotic arm controller. It can move horizontally and vertically under the control command of the robotic arm controller, and suck up the end of the cigarette gift box and pull it up to follow the movement to the outside of the cigarette gift box.

[0023] The robot controller is used to receive images sent from the image acquisition station, process and recognize them, determine the position of the pull tab end inside the current cigarette gift box, calculate the robot's operation path, convert it into control commands, and send them to the robot.

[0024] Furthermore, it also includes a switch, which is connected to the industrial camera, the robot controller, and the robot. The industrial camera is connected to the switch via an Ethernet cable, the switch and the robot controller transmit data via an Ethernet cable, and the robot controller and the robot are connected via a communication cable.

[0025] Furthermore, the end of the robotic arm includes a robotic arm and a rotating motor installed at the bottom of the robotic arm. A horizontal mounting plate is connected to the output end of the rotating motor. The rotating motor can drive the horizontal mounting plate to rotate horizontally. The end of the mounting plate is provided with a mounting groove. The suction nozzle is arranged vertically, and the tail end of the suction nozzle is installed in the mounting groove. The suction nozzle is connected to the air pipe.

[0026] When the tip of the pull tab is close to the edge of the cigarette gift box, the robotic arm controls the rotation of the mounting plate to make the mouthpiece contact the tip of the pull tab.

[0027] Furthermore, the adjustable camera mounting bracket includes an adjustable vertical mounting plate, a bracket mounting base, and a lighting mounting bracket; the adjustable vertical mounting plate has several height adjustment holes distributed along the vertical direction, and the bracket mounting base has a mounting hole; the adjustable vertical mounting plate and the bracket mounting base are fixedly connected by fastening bolts passing through the mounting hole and the height adjustment hole; the top of the adjustable vertical mounting plate has two threaded holes for mounting and fixing the industrial camera and the lighting lamp.

[0028] Furthermore, the suction nozzle of the robotic arm is connected to an airflow switching valve via an air pipe. The airflow switching valve is connected to a positive pressure air pipe and a negative pressure air pipe respectively, which can realize the switching between positive and negative airflow. The airflow switching valve can control the positive pressure airflow to pass through and flow out of the suction nozzle, and can also stop the positive pressure airflow from blowing out and turn to suck in the negative pressure airflow, so as to realize the suction function of the suction nozzle.

[0029] The working principle of this invention: The precise pickup method of this invention is based on visual imaging technology. It uses an industrial camera to identify the pull tab in the target cigarette gift box. Based on the stereo imaging technology of the industrial camera, the coordinate position of the pull tab end is determined in the coordinate system of the industrial camera. Then, it is compared with the standard coordinates corresponding to a standard qualified pull tab to determine whether the pull tab in the current cigarette gift box is off-center. If the off-center amount exceeds the range covered by the mouthpiece at the standard position, it is determined to be a skewed pull tab. The current coordinate position is sent to the robot controller, so that the robot performs displacement compensation with the coordinate position as the target position. It can drive the mouthpiece to the position above the skewed pull tab, and then lower it. After the mouthpiece is suctioned by negative pressure, it is pulled up until the predetermined position, so that the pull tab is rotated outward to the outer end of the cigarette gift box, and then enters the next station. The robot resets, and the position of the robot reset position is the standard position. If there is no deviation of the pull tab, the robot does not need to perform displacement compensation and can simply follow the original standard mode to pull the pull tab. Besides the left-right deviation of the pull tab, some pull tabs may curl upwards due to bonding errors during the bonding process or because they have been folded. When the pull tab curls upwards, it is positioned above the box surface. If the suction nozzle is used to press down directly, the stiffness of the folded part and the pull tab's own resilience can cause it to slip or shift off the nozzle during the downward movement, preventing the nozzle from accurately adhering to the pull tab. To address this, this invention uses positive pressure air blowing downwards from the suction nozzle to guide the pull tab smoothly onto the box surface. At this point, the suction nozzle switches, stops the positive pressure air, presses down until it contacts the end of the pull tab, and then negative pressure air is introduced, successfully adhering to the pull tab. This invention also provides a method for determining whether the pull tab is curled too high when only image data recognition and positioning are used, without using a stereoscopic industrial camera. This method calculates the intensity of the shadow edge to determine if the pull tab is curled too high. When the pull tab is curled up, its distance from the box surface is too large, resulting in a blurry projection and a weak shadow edge. Therefore, the intensity of the shadow edge is used to determine whether the pull tab is in a high position. Positive pressure airflow is used only when the tongue is raised high. The downward airflow quickly presses down on the end of the tongue, causing it to press downwards against the box surface until the mouthpiece approaches. The short time and large airflow area make the tongue end less likely to spring back and ensure a high success rate of pressing down. Structurally, this invention does not modify the gift box cigarette packaging machine; the equipment is installed along its conveyor line for use.

[0030] Beneficial technical effects of the present invention:

[0031] Visual imaging technology is used to identify and locate the pull tabs in cigarette gift boxes, enabling precise pickup of the pull tabs. Industrial cameras and image processing algorithms are employed to automatically detect and compensate for pull tab misalignment and tilting, reducing manual operation and improving automated production efficiency.

[0032] By comparing with standard coordinates, the pose error is calculated. When it exceeds the preset value, a robotic arm is used to perform displacement compensation and movement correction to ensure accurate positioning even for abnormal tongue pulls.

[0033] By determining whether the cigarette tab is excessively raised, if so, positive pressure air is used to blow downwards to suppress the raised tab, thus enabling precise pickup of the tab even when it is raised. This achieves accurate pickup of cigarette gift box tabs, reduces the probability of tab defects, improves production efficiency and product quality, and has high practicality and economic benefits. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of coordinate axes for a precise picking method of the cigarette gift box pull tab according to the present invention;

[0035] Figure 2 This is a schematic diagram of the structure of a precise pickup system for cigarette gift box pull tabs according to the present invention;

[0036] Figure 3 This is a schematic diagram illustrating the precise pickup system for cigarette gift box pull tabs according to the present invention, where the pull tab is picked up at a standard position.

[0037] Figure 4 This is a schematic diagram of the precise pickup system for cigarette gift box pull tabs according to the present invention, which picks up the pull tab offset in the positive Y-axis direction;

[0038] Figure 5 This is a schematic diagram of the precise pickup system for cigarette gift box pull tabs according to the present invention, which picks up the pull tab offset in the positive X-axis direction;

[0039] Figure 6 This is a schematic diagram of the precise pickup system for cigarette gift box pull tabs according to the present invention, which picks up the pull tab offset in the positive Z-axis direction;

[0040] Figure 7 This is a schematic diagram illustrating the process of a precise pickup system for cigarette gift box pull tabs according to the present invention.

[0041] Figure 8 This is a schematic diagram of the process of picking up the offset pull tab of a cigarette gift box using a precise picking system according to the present invention;

[0042] Figure 9 This is a schematic diagram illustrating the process principle of using positive pressure air to fix the upturned pull tab in a precise picking method for cigarette gift box according to the present invention.

[0043] Figure 10 This is a perspective view of the installation structure of the lighting device and industrial camera in the precision pickup system for cigarette gift box pull tabs of the present invention.

[0044] Figure 11This is a schematic diagram of the basic process of a precise picking method for the cigarette gift box pull tab of the present invention.

[0045] Among them: 1—Lighting device, 2—Industrial camera, 3—Adjustable camera mounting bracket, 31—Adjustable vertical mounting plate, 32—Bracket mounting base, 33—Lighting lamp mounting bracket, 4—Robot arm, 41—Suction nozzle, 42—Robot arm, 43—Rotating motor, 44—Horizontal mounting plate, 45—Mounting slot, 46—Air pipe, 47—Airflow conversion valve, 48—Positive pressure air pipe, 49—Negative pressure air pipe, 5—Cigarette gift box, 6—Robot arm controller, 7—Exchanger, 8—Tip. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0047] Example 1: A method for accurately picking up the pull tab of a cigarette gift box, used to pull up the pull tab of the cigarette gift box 5 to the outer end of the gift box on the production conveyor line of a cigarette gift box packaging machine, including the following steps:

[0048] Step S1: The cigarette gift box 5 is conveyed on the production conveyor line and arrives at the image acquisition station. The industrial camera 2 takes a picture of the cigarette gift box 5 directly below and acquires image data. The image acquisition station has a stereo imaging function, which can obtain the height position information of the tongue tip.

[0049] Step S2: Establish a coordinate system based on the location of the workstation obtained from the image, and determine the standard coordinate information of the qualified pull tab in the coordinate system; the coordinate system is a three-dimensional coordinate system, and the current position information of the pull tab in the coordinate system includes the horizontal position information and the height position information of the pull tab end; Step S4 includes comparing the current height position information of the pull tab end with the surface height information of the cigarette gift box 5. If the height position information is greater than the surface height information of the cigarette gift box 5 and exceeds the height threshold, it is determined that the pull tab is raised too high.

[0050] Step S3: Perform visual recognition processing on the image data, taking the pull tab inside the cigarette gift box 5 as the recognition object, and determine the current position information of the pull tab in the coordinate system;

[0051] Step S4: Based on the current position information, compare it with the standard coordinate information of the qualified tongue puller, calculate the pose error. If the pose error is greater than the preset value, it is judged as tongue puller offset, and obtain the offset coordinate difference corresponding to the pose error.

[0052] In step S5, when the cigarette gift box 5 arrives at the suction station of the robot arm 4, the robot arm 4 is in a standard position. If the positional error does not exceed the preset value, the robot arm 4 performs standardized actions. If the positional error exceeds the preset value, the robot arm 4 performs displacement compensation and movement correction based on the offset coordinate difference, and performs subsequent actions such as moving the suction nozzle 41 downward, sucking up the tongue and following it into position.

[0053] Preferably, the height position information of the tongue tip is obtained by processing the image acquired by the industrial camera 2, including the following steps:

[0054] Image data of the cigarette gift box 5 is acquired. Gaussian filtering or median filtering is used to filter and reduce noise in the image to avoid the influence of noise on shadow edge detection. The image is then converted to grayscale for shadow edge detection. Since edge detection is mainly based on color abrupt changes, color information is not needed. Converting the image to grayscale reduces complexity. At this stage, the image can be filtered and denoised to avoid the influence of noise on edge detection. Gaussian filtering or median filtering is commonly used.

[0055] Edge detection is performed by convolving an image to calculate the gradient magnitude and direction of each pixel. This gradient magnitude calculation can be used to perform edge detection. Operators such as Sobel, Prewitt, Robert, and Laplacian can be used to convolve the image to calculate the gradient magnitude and direction of each pixel.

[0056] Gradient thresholding is performed on the shadow edge image, setting a high threshold and a low threshold. Gradients above the high threshold are labeled as strong edges, those below the low threshold as non-edges, and those above the low threshold but below the high threshold as weak edges. Weak edges are filtered out, retaining only edges of strong intensity. Typically, two thresholds are set: a high threshold and a low threshold. Gradients above the high threshold are labeled as strong edges, those below the low threshold as non-edges, and those above the low threshold but below the high threshold undergo further evaluation. For the remaining weak edges, if there are pixels of strong edges surrounding a weak edge, the weak edge is retained; otherwise, it is deleted.

[0057] The shadow intensity is estimated by calculating the shadow edge intensity, and a correspondence is established between the height information of the tongue tip and the shadow intensity based on a machine self-learning algorithm. This allows the height information of the tongue tip to be obtained based on image recognition. When the tongue tip is raised, its distance from the box surface is too large, resulting in a blurry projection, which falls under the category of weak shadow edge intensity. Therefore, the shadow edge intensity is used to determine whether the tongue tip is in a high position.

[0058] Preferably, the height position information of the pull tab end acquired at the image acquisition station is compared with the difference between the image and the gift box surface. If the difference is greater than a preset value, it is determined that the pull tab is too high. When the pull tab is too high, the suction nozzle 41 of the robotic arm 4 blows positive pressure air outward during the downward movement. After descending to a predetermined height, it stops blowing positive pressure air and switches to suction negative pressure air to accurately suck up the pull tab end. Positive pressure air is only used when the pull tab is high up. The downward airflow can quickly press down the end of the pull tab so that it is pressed down against the box surface until the suction nozzle 41 approaches. The time is short and the airflow area is large, making it difficult for the pull tab end to bounce back and ensuring a high success rate of pressing down.

[0059] Example 2: A precision pickup system for cigarette gift box pull tabs, applied to the production conveyor line of a gift box cigarette packaging machine, comprising:

[0060] The image acquisition station, located directly above the production conveyor line, includes a lighting device 1, an industrial camera 2, and an adjustable camera mounting bracket 3; it is used to illuminate the top of the cigarette gift box 5 and capture images, and then send the captured images to the robot controller 6.

[0061] The robotic arm 4 is located at the suction station on the production line, after the image acquisition station. It includes the robotic arm 4 and the suction nozzle 41. The suction nozzle 41 is located at the end of the robotic arm 4 and is connected to the robotic arm controller 6. It can be moved horizontally and vertically by the control command of the robotic arm controller 6, and suck up the end of the pull tab inside the cigarette gift box 5 and pull it up to follow the movement to the outside of the end of the cigarette gift box 5.

[0062] The robot controller 6 is used to receive images sent from the image acquisition station, process and recognize them, determine the position information of the pull tab end inside the current cigarette gift box 5, and calculate the operation path of the robot 4, convert it into control commands and send them to the robot 4.

[0063] Preferably, the system also includes a switch 7, which is connected to the industrial camera 2, the robot controller 6, and the robot 4. The industrial camera 2 is connected to the switch 7 via an Ethernet cable, the switch 7 is connected to the robot controller 6 via an Ethernet cable to transmit data, and the robot controller 6 is connected to the robot 4 via a communication cable.

[0064] In this embodiment, the industrial camera is a COGNEX ISM1020-1 industrial camera. This industrial camera is an advanced optical instrument capable of quickly and accurately acquiring three-dimensional images. It features high precision, high speed, and high reliability, and can acquire high-quality images under various lighting conditions, while also operating stably in harsh environments. The position coordinates of the industrial camera are 700, 30, -10mm, and the coordinate axes are as follows: Figure 1As shown. The industrial camera lighting uses LED lighting, featuring high brightness, low energy consumption, and long service life. The industrial camera lighting has a square structure, and the industrial camera head is fixed to the center of the lighting via threads. The adjustable mounting bracket for the industrial camera lighting includes an adjustable vertical mounting plate 31, a bracket mounting base 32, and a lighting mounting bracket 33. The adjustable vertical mounting plate 31 has six height adjustment holes distributed along the vertical direction, and the bracket mounting base 32 has one mounting hole. The adjustable vertical mounting plate 31 and the bracket mounting base 32 are fixedly connected by fastening bolts. Additionally, the top of the adjustable vertical mounting plate 31 has two threaded holes for fixing the industrial camera lighting mounting bracket 33. The industrial-grade switch 7 uses a TP-LINK industrial Ethernet PoE switch 7, product model TL-SF1005P. The switch 7 has good compatibility, strong power supply reliability, a compact aluminum alloy body, is robust and durable, and has efficient heat dissipation, allowing it to operate stably in various harsh environments. The industrial camera is connected to the industrial switch 7 via an Internet cable. The ABB robotic arm 4, model IRB910SC-3 / 0.65, is not only fast and costly but also highly precise. It boasts a repeatability of 0.01 mm, a path repeatability of 0.07–0.16 mm, a point-to-point accuracy of 0.02 mm, and a point-to-point path accuracy of 0.21–0.38 mm. The ABB pull tab gripping mechanism employs point-to-point motion with an accuracy of 0.21–0.38 mm. A pull tab suction nozzle 41 is fixed to the ABB robotic arm 4. The robotic arm controller 6 is a matching device for the robotic arm 4, used to receive image signals acquired and processed by the industrial camera and control the robotic arm 4's movements based on these signals. A schematic diagram of the cigarette pack pull tab precision pickup system installation is shown below. Figure 2 To achieve precise pickup of the carton's pull tab, the industrial camera is connected to the switch 7 via an Ethernet cable. The switch 7 and the controller also transmit data via Ethernet. The controller and the ABB robot arm 4 are connected via a communication cable. The industrial camera visually detects and processes the image signal of the gift box on the conveyor channel, then transmits the signal to the ABB robot arm controller 6 via the switch 7. The controller uses an algorithm to locate the pull tab and calculates the pose error, further controlling the ABB robot arm 4 to precisely pick up the pull tab. The visual positioning robot arm 4 picks up the pull tab as follows: Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown.

[0065] Preferably, the end of the robotic arm 4 includes a robotic arm 42 and a rotating motor 43 mounted at the bottom of the robotic arm 42. A horizontal mounting plate 44 is connected to the output end of the rotating motor 43. The rotating motor 43 can drive the horizontal mounting plate 44 to rotate horizontally. The end of the mounting plate is provided with a mounting groove 45. The suction nozzle 41 is arranged vertically, and the tail end of the suction nozzle 41 is installed in the mounting groove 45. The suction nozzle 41 is connected to the air pipe 46. When the end of the pull tab is close to the edge of the cigarette gift box 5, the robotic arm 4 controls the rotation of the mounting plate so that the suction nozzle 41 can contact the end of the pull tab, thereby avoiding the limitation of the height of the box edge on the downward movement position of the suction nozzle 41. In this embodiment, a schematic diagram of the connection between the rotating motor 43 and the mounting plate is not given; however, the transmission technology of the rotating motor 43 driving the plate to rotate is existing technology, so the specific structural details are not described in detail.

[0066] Preferably, the adjustable camera mounting bracket 3 includes an adjustable vertical mounting plate 31, a bracket mounting base 32, and a lighting mounting bracket 33; the adjustable vertical mounting plate 31 has several height adjustment holes distributed along the vertical direction, and the bracket mounting base 32 has a mounting hole; the adjustable vertical mounting plate 31 and the bracket mounting base 32 are fixedly connected by fastening bolts passing through the mounting hole and the height adjustment hole; the top of the adjustable vertical mounting plate 31 has two threaded holes for mounting and fixing the industrial camera 2 and the lighting lamp.

[0067] Preferably, the suction nozzle 41 of the robotic arm 4 is connected to an airflow switching valve 47 via an air pipe 46. The airflow switching valve 47 is connected to the robotic arm controller 6, which controls the on / off flow of positive and negative pressure airflow through the airflow switching valve 47. This allows the air pipe 46 to expel air from the nozzle when necessary, and to apply negative pressure for inhalation when sucking up the tongue. Therefore, the airflow switching valve 47 is connected to both a positive pressure air pipe 48 and a negative pressure air pipe 49, enabling switching between positive and negative airflow. The airflow switching valve 47 can control the passage of positive pressure airflow through and out of the suction nozzle 41, and can also stop the positive pressure airflow and switch to suction of negative pressure airflow, thus realizing the suction function of the suction nozzle 41. The airflow switching valve 47 is a commercially available product. One end of the airflow switching valve 47 is connected to both the positive pressure air pipe 48 and the negative pressure air pipe 49, while the other end is directly connected to the air pipe 46. The air pipe 46 connects to the suction nozzle 41 on the robotic arm 4. When the airflow switching valve 47 controls the connection of positive pressure airflow, the negative pressure suction is stopped. When negative pressure suction is performed, the connection of positive pressure airflow is stopped, and the negative pressure air pipe 49 is connected. This enables the suction nozzle 41 to serve a dual purpose, ensuring the accuracy of airflow direction and allowing for rapid, precise, and stable downward pressure on the tongue.

[0068] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A method for accurately picking up the pull tab of a cigarette gift box, characterized in that, The method for automatically pulling up the tab in a cigarette gift box (5) and pulling it to the outside of the gift box on the production conveyor line of a cigarette gift box packaging machine includes the following steps: Step S1: The cigarette gift box (5) is conveyed on the production conveyor line and arrives at the image acquisition station. The industrial camera (2) takes a picture of the cigarette gift box (5) directly below and acquires the image data. Step S2: Establish a coordinate system based on the location of the image acquisition station, and determine the standard coordinate information of the qualified tongue in the coordinate system; the image acquisition station has a stereo imaging function, and the height position information of the tongue end can be obtained based on the stereo imaging function. Step S3: Perform visual recognition processing on the image data, taking the pull tab inside the cigarette gift box (5) as the recognition object, and determine the current position information of the pull tab in the coordinate system; the coordinate system is a three-dimensional coordinate system, and the current position information of the pull tab in the coordinate system includes the horizontal position information and the height position information of the pull tab end; Step S4: Based on the current position information, compare it with the standard coordinate information of the qualified tongue puller, calculate the pose error. If the pose error is greater than the preset value, it is judged as tongue puller offset, and obtain the offset coordinate difference corresponding to the pose error. In step S5, when the cigarette gift box (5) reaches the suction station of the robot (4), the robot (4) is in a standard position. If the positional error does not exceed the preset value, the robot (4) performs standardized actions. If the positional error exceeds the preset value, the robot (4) performs displacement compensation and movement correction based on the offset coordinate difference, and performs the subsequent actions of moving the suction nozzle (41) down, sucking up the tongue and following it into position. Step S4 includes comparing the height position information of the current pull tongue tip with the surface height information of the cigarette gift box (5). If the height position information is greater than the surface height information of the cigarette gift box (5) and exceeds the height threshold, it is determined that the pull tongue is raised too high. The height position information of the pull tab obtained by the image acquisition station is compared with the difference of the gift box surface. If the difference is greater than the preset value, it is judged that the pull tab is too high. When the pull tab is too high, the suction nozzle (41) of the robot (4) blows out positive pressure air during the downward movement. After descending to the predetermined height, it stops blowing out positive pressure air and switches to suction negative pressure air to accurately suck up the pull tab.

2. The method for accurately picking up the cigarette gift box tab according to claim 1, characterized in that, The height position information of the pull tongue end is obtained by processing the image acquired by the industrial camera (2), including the following steps: Obtain the image data inside the cigarette gift box (5), use Gaussian filtering or median filtering to filter and reduce noise in the image, avoid the influence of noise on shadow edge detection, and convert the image into a grayscale image for shadow edge detection; By convolving the image, the gradient magnitude and direction of each pixel are calculated, and edge detection is performed by calculating the gradient magnitude of each pixel. Gradient thresholding is performed on the shadow edge image, setting a high threshold and a low threshold. Edges with gradients higher than the high threshold are labeled as strong edges, those with gradients lower than the low threshold are labeled as non-edges, and those with gradients higher than the low threshold but lower than the high threshold are labeled as weak edges. The shadow intensity is inferred by the shadow edge intensity, and a correspondence is established between the height information of the tongue tip and the shadow intensity based on the machine self-learning algorithm, thereby obtaining the height information of the tongue tip based on image recognition.

3. A system based on the precise picking method for cigarette gift box tabs as described in claim 1 or 2, applied to the production conveyor line of a gift box cigarette packaging machine, characterized in that... include: The image acquisition station, located directly above the production conveyor line, includes a lighting device (1), an industrial camera (2), and an adjustable camera mounting bracket (3); used to illuminate the top of the cigarette gift box (5) and capture images, and send the captured images to the robot controller (6). The robotic arm (4) is located on the production line and is set after the image acquisition station. It includes the robotic arm (4) and the suction nozzle (41). The suction nozzle (41) is set at the end of the robotic arm (4) and is connected to the robotic arm controller (6). It can be moved horizontally and vertically by the control command of the robotic arm controller (6) and suck up the end of the pull tab inside the cigarette gift box (5) and pull it up to follow the movement to the outside of the end of the cigarette gift box (5). The robot controller (6) is used to receive images sent by the image acquisition station, process and recognize them, determine the position information of the pull tab end in the current cigarette gift box (5), and calculate the operation path of the robot (4) and convert it into control instructions to be sent to the robot (4).

4. The precise pickup system for the cigarette gift box pull tab according to claim 3, characterized in that, It also includes a switch (7), which is connected to an industrial camera (2), a robot controller (6) and a robot (4). The industrial camera (2) is connected to the switch (7) via an Ethernet cable. The switch (7) and the robot controller (6) transmit data via an Ethernet cable. The robot controller (6) and the robot (4) are connected via a communication cable.

5. The precise picking system for cigarette gift box pull tabs according to claim 3, wherein the end of the robotic arm (4) includes a robotic arm (42) and a rotating motor (43) installed at the bottom of the robotic arm (42), the horizontal mounting plate (44) is connected to the output end of the rotating motor (43), the rotating motor (43) can drive the horizontal mounting plate (44) to rotate horizontally, the end of the mounting plate is provided with a mounting groove (45), the suction nozzle (41) is arranged vertically, the tail end of the suction nozzle (41) is installed in the mounting groove (45), and the suction nozzle (41) is connected to the air pipe (46); When the tip of the pull tab is close to the edge of the cigarette gift box (5), the robotic arm (4) controls the rotation of the mounting plate so that the mouthpiece (41) can contact the tip of the pull tab.

6. The precise pickup system for cigarette gift box pull tabs according to claim 3, wherein the adjustable camera mounting bracket (3) includes an adjustable vertical mounting plate (31), a bracket mounting base (32), and a lighting mounting bracket (33); the adjustable vertical mounting plate (31) has several height adjustment holes distributed along the vertical direction, and the bracket mounting base (32) has a mounting hole; the adjustable vertical mounting plate (31) and the bracket mounting base (32) are fixedly connected by fastening bolts passing through the mounting hole and the height adjustment hole; the top of the adjustable vertical mounting plate (31) has two threaded holes for mounting and fixing the industrial camera (2) and the lighting lamp.

7. The precise picking system for cigarette gift box pull tabs according to claim 3, wherein the mouthpiece (41) of the robotic arm (4) is connected to the airflow switching valve (47) through the air pipe (46), and the airflow switching valve (47) is connected to the positive pressure air pipe (48) and the negative pressure air pipe (49) respectively, which can realize the switching between positive and negative airflow; the airflow switching valve (47) can control the positive pressure airflow to pass through and flow out of the mouthpiece (41), and can also stop the positive pressure airflow from blowing out and turn to suck in the negative pressure airflow, thereby realizing the adsorption function of the mouthpiece (41).

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