Accurate picking method and system for cigarette gift box pull tongues

Abstract

The invention discloses a method and a system for accurately picking up pull tongues of cigarette gift boxes, which are used for carrying out follow-up pull-up on pull tongues in the cigarette gift boxes on a production conveying line of a gift box cigarette packaging machine and pulling the pull tongues to the outer ends of the gift boxes, image signals of the cigarette gift boxes are collected by an industrial camera and are processed to obtain position information, and the position information of the cigarette gift boxes is obtained. And the processed image signal is transmitted to the ABB controller through the switch. After the ABB controller obtains the image signal, the main program judges whether the offset of the position of the pull tongue is too large or not, if the offset is not large, the main program continues to be executed, and if the offset is too large, an error algorithm subprogram is executed, the offset is calculated, then an offset pull tongue tracking subprogram is executed, the motion trail of the offset pull tongue is read, and accurate picking of the pull tongue is achieved; therefore, the defect rate of cigarettes with abnormal pull tongues is greatly reduced, carton cigarettes with pull tongue folding quality problems are reduced and even prevented from entering the next process, unqualified carton cigarettes can be timely removed, and the product quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of functional applications of gift box cigarette packaging machines, and specifically to a precise picking method and system for the pull tabs of cigarette gift boxes. Background Art

[0002] The YB621D gift box cigarette packaging machine is a special-shaped packaging machine, a non-standard customized device, with a simple and reasonable structure and convenient operation. It mainly completes functions such as filling small packs into gift boxes, sorting cellophane, picking up pull tabs, attaching sealing labels, and packaging the carton with cellophane. Since cigarette gift boxes are handmade products, it is difficult to strictly control the production process standards, resulting in a large number of the above-mentioned carton pull tabs being found to have excessive position offsets during use. The existing technical solution of the YB621D gift box cigarette packaging machine is to use a non-positioning ABB manipulator to grab the pull tab. If the offset of the pull tab position exceeds the grabbing error range of the ABB manipulator, the pull tab cannot be successfully sucked, resulting in the inability to complete the next folding step, and this cigarette will be rejected at the subsequent rejection mechanism. That is, during the process of picking up the pull tab, due to the deviation of the pull tab position, the robotic arm cannot ensure successful picking every time.

[0003] It can be seen that the use of a non-positioning ABB manipulator to grab the pull tab by the YB621D gift box cigarette packaging machine has an unsatisfactory effect, and the defect rate of abnormal pull tab cigarette cartons remains high. Specifically, as long as the offset of the pull tab position is too large, the ABB manipulator cannot successfully grab the pull tab. If defective products with quality defects in the folding of the pull tab are found during the production process at subsequent workstations, only rework can be carried out, resulting in a large amount of material waste and labor consumption, which not only affects production efficiency but also increases production costs. If products with quality defects in the folding of the pull tab flow into the market, this will greatly reduce the consumer experience, and at the same time damage the trust of the brand in the hearts of consumers, affect the reputation of the enterprise, thereby affecting the sales volume of the product, and further affecting the efficiency of the enterprise.

[0004] There are often phenomena where the folding of the pull tab does not meet the packaging process requirements, such as: tearing at the bottom of the pull tab, pressing the bottom of the pull tab, folding the pull tab inward, folding the pull tab outward, skewing of the pull tab, etc., which affect the packaging quality of carton cigarettes. Through detection data, it is found that in the current production process flow, the defect rate of abnormal pull tabs is relatively high, which leads to a significant increase in the rejection volume of carton cigarettes, seriously restricting the operation efficiency of the equipment, causing waste of manpower and material resources. More importantly, continuous failure to pick up the pull tab may result in incomplete rejection of defective carton cigarettes, thus flowing into the market. Therefore, it is very necessary to invent a precise picking system for the pull tabs of cigarette cartons, which can greatly reduce the defect rate of abnormal pull tab carton cigarettes. Summary of the Invention

[0005] In order to solve the above-mentioned deficiencies and defects in the prior art, the inventor provides a new solution, which aims to realize a system and method for accurately picking up the pull tab, solve the problem that the pull tab is too offset due to various reasons and the ABB manipulator cannot successfully pick it up, thereby greatly reducing the defect rate of cigarette cartons with abnormal pull tabs, reducing or even eliminating the entry of cigarette cartons with pull tab folding quality problems into the next process at the source, ensuring that unqualified cigarette cartons can be removed in time, and finally achieving the invention purpose of improving product quality. Specifically, the present invention is implemented as follows:

[0006] A method for accurately picking up a pull tab of a cigarette gift box is used to pull up the pull tab in a cigarette gift box and pull it to the outer end of the gift box on a production conveyor line of a gift box cigarette packaging machine, comprising the following steps:

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

[0008] Step S2, establishing a coordinate system based on the position of the image acquisition station, and determining standard coordinate information of a qualified pull tab in the coordinate system;

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

[0010] Step S4, based on the comparison between the current position information and the standard coordinate information of the qualified pull tab, the posture error is calculated, if the posture error is greater than a preset value, it is judged as the pull tab offset, and the offset coordinate difference corresponding to the posture error is obtained;

[0011] Step S5, when the cigarette gift box arrives at the robot suction station, the robot is in the standard position. If the posture error does not exceed the preset value, the robot performs standardized actions; if the posture error exceeds the preset value, the robot performs displacement compensation movement correction based on the offset coordinate difference, executes the subsequent actions of moving the suction nozzle down, sucking the pull tab and moving it into place.

[0012] Furthermore, step S3 includes: the coordinate system is a three-dimensional coordinate system, and it is determined that the current position information of the pull tab in the coordinate system includes horizontal position information and height position information of the pull tab end; step S4 includes, based on the comparison of the current height position information of the pull tab end with 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 by exceeding the height threshold, it is determined that the pull tab is lifted too high.

[0013] Furthermore, the image acquisition station has a stereoscopic imaging function, based on which the height position information of the tongue tip can be obtained.

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

[0015] Obtain image data from the cigarette gift box, use Gaussian filtering or median filtering to filter and reduce noise on the image to avoid the influence of noise on shadow edge detection, and convert the image into a grayscale image for shadow edge detection;

[0016] By convolving the image, the gradient size and direction of each pixel are calculated, and the gradient size of the pixel is calculated for edge detection;

[0017] Perform gradient thresholding on the shadow edge image, set a high threshold and a low threshold, and mark the gradient above the high threshold as a strong edge, the gradient below the low threshold as a non-edge, and the gradient above the low threshold but below the high threshold as a weak threshold.

[0018] The shadow intensity is inferred by the shadow edge intensity, and a corresponding relationship is established between the pull tab end height information and the shadow intensity based on machine self-learning algorithm training, so as to obtain the pull tab end height information based on image recognition.

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

[0020] Another aspect of the present invention provides a precise picking system for a cigarette gift box pull tab, which is applied to a production conveyor line of a gift box cigarette packaging machine, and comprises:

[0021] The image acquisition station is located directly above the production conveyor line and 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 the cigarette gift box, and send the captured images to the robot controller;

[0022] The manipulator suction station is located on the production conveyor line and is set after the image acquisition station. It includes a manipulator and a suction nozzle. The suction nozzle is set at the end of the manipulator and is connected to the manipulator controller. It can be controlled by the manipulator controller to move horizontally and vertically, and absorb the end of the pull tab in the cigarette gift box, and pull it up and move it to the outside of the cigarette gift box end.

[0023] The robot controller is used to receive the image sent by the image acquisition station, process and identify it, determine the position information of the end of the pull tab in the current cigarette gift box, and calculate the operation path of the robot, convert it into a control command and send it to the robot.

[0024] Further, it also includes a switch, which is connected to the industrial camera, the manipulator controller and the manipulator. The industrial camera is connected to the switch through an Ethernet cable. The switch and the manipulator controller transmit data using an Ethernet cable. The manipulator controller is connected to the manipulator through a communication cable.

[0025] Further, the end of the manipulator includes a robotic arm rod and a rotating motor installed at the bottom end of the robotic arm rod. The 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. There is a mounting groove at the end of the mounting plate. 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 an air pipe.

[0026] When the end position of the pulling tongue is close to the edge of the cigarette gift box, the manipulator can make the suction nozzle contact the end position of the pulling tongue by controlling the rotation of the mounting plate.

[0027] Further, the camera adjustable mounting bracket includes an adjustable vertical mounting plate, a bracket mounting base, and a lighting lamp mounting bracket. A number of height adjustment holes are distributed vertically on the adjustable vertical mounting plate. There is a mounting hole on the bracket mounting base. The adjustable vertical mounting plate and the bracket mounting base are fixedly connected by a fastening bolt passing through the mounting hole and the height adjustment hole. There are two threaded holes at the top of the adjustable vertical mounting plate for installing and fixing the industrial camera and the lighting lamp.

[0028] Further, the suction nozzle of the manipulator is connected to an air flow conversion valve through an air pipe. The air flow conversion valve is respectively connected to a positive pressure air pipe and a negative pressure air pipe, and can realize the switching between positive and negative air flows. The air flow conversion valve can control the positive pressure air flow to pass through and flow out from the suction nozzle, and can also stop the blowing of the positive pressure air flow and instead inhale the negative pressure air flow to realize the adsorption function of the suction nozzle.

[0029] Working principle of the present invention: The precise picking method of the present invention is based on visual imaging technology. An industrial camera is used to identify the pull tab in the target cigarette gift box, and based on the stereo imaging technology of the industrial camera, the coordinate position of the end of the pull tab is determined within the coordinate system of the industrial camera, and then compared with the standard coordinates corresponding to the standard qualified pull tab, so as to determine whether the pull tab in the current cigarette gift box is offset; if the offset exceeds the range covered by the nozzle at the standard position, it is determined as a skewed pull tab, and it is sent to the manipulator controller based on its current coordinate position, so that the manipulator takes this coordinate position as the target position for displacement compensation, enabling it to drive the nozzle to reach above the position of the skewed pull tab, and then descend, so that the nozzle adsorbs the end part of the pull tab through negative pressure, and then follows and pulls up until the predetermined position, so that the pull tab rotates outwards to the outer end of the cigarette gift box, and then enters the next working station; the manipulator resets, and the reset position of the manipulator is the standard position. If the pull tab is not offset, the manipulator does not need to perform displacement compensation and can execute the original standard mode to follow and pull the pull tab. In addition to the left and right offsets of the pull tab, some pull tabs have bonding errors due to the bonding link, or the pull tab is folded, resulting in the pull tab warping. In the case of the warped pull tab, since the pull tab is at a height higher than the box surface, if the nozzle is directly pressed down, in the case of a hard folding part of the pull tab and the resilience of the pull tab itself, it will slip off and offset from the nozzle during the downward movement, resulting in the nozzle being unable to accurately adsorb the pull tab. For this situation, the present invention blows positive pressure air downward from the nozzle, which can blow the pull tab down to make it smoothly adhere to the box surface. At this time, the nozzle switches, stops the positive pressure air, presses down in place, and after contacting the end of the pull tab, negative pressure air is connected, and then the pull tab is successfully adsorbed; the present invention also gives that if an industrial camera with stereo imaging is not used, when only image data recognition and positioning image processing is performed, it is also possible to judge whether the pull tab is in a situation of excessive warping by calculating the intensity of the shadow edge. Since when the pull tab warps, the distance from it to the box surface is too large, the generated projection is relatively virtual, which belongs to the situation of weak shadow edge intensity, so as to judge whether the pull tab is at a high position through the shadow edge intensity. Only when the pull tab is in a situation of relatively high warping, positive pressure air is blown downward. The downward blowing air flow can quickly press down the end part of the pull tab to make it adhere to the box surface as a whole until the nozzle approaches. The time is short and the air flow area is large, so that the end of the pull tab is not easy to rebound and reset and the success rate of pressing down is high. Structurally, the present invention does not modify the cigarette gift box packaging machine, but installs equipment along its conveyor line for use.

[0030] Advantageous technical effects of the present invention:

[0031] The pull tab in the cigarette gift box is identified and positioned by using visual imaging technology, so as to realize the precise picking of the pull tab. Through the industrial camera and image processing algorithm, the automatic detection and compensation of the offset and warping of the pull tab are realized, manual operation is reduced, and the automation production efficiency is improved.

[0032] By comparing with the standard coordinates, the position error is calculated. When it exceeds the preset value, the robot is used to perform displacement compensation movement correction to ensure that the abnormal pull tab can also be accurately positioned.

[0033] By judging whether the pull tab is lifted too high, if so, positive pressure air is used to blow downward to suppress the lifted pull tab, so that the lifted pull tab can also be accurately sucked up. The pull tab of the cigarette gift box is accurately picked up, the probability of abnormal defects of the pull tab is reduced, the production efficiency and product quality are improved, and it has high practicality and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0036] Figure 3 It is a schematic diagram of a precise picking system for picking up a pull tab of a cigarette gift box according to the present invention, picking up a pull tab at a standard position;

[0037] Figure 4 It is a schematic diagram of a precise picking system for picking up a pull tab of a cigarette gift box according to the present invention, picking up a pull tab that is positively offset in the Y-axis;

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

[0039] Figure 6 It is a schematic diagram of a precise picking system for picking up a pull tab of a cigarette gift box according to the present invention, picking up a pull tab that is offset in the positive direction of the Z axis;

[0040] Figure 7 It is a schematic diagram of the process of picking up a pull tab by a precise picking system for a pull tab of a cigarette gift box of the present invention;

[0041] Figure 8 It is a schematic diagram of the process of picking up a deviated pull tab by a precise picking system for a pull tab of a cigarette gift box according to the present invention;

[0042] Figure 9 It is a schematic diagram of the principle of the process of using positive pressure wind to fix the upward pull tab in a method for accurately picking up the pull tab of a cigarette gift box of the present invention;

[0043] Figure 10 It is a three-dimensional diagram of the installation structure of the lighting device and the industrial camera in the structure of the precise picking system for the pull tab of a cigarette gift box of the present invention;

[0044] Figure 11It is a basic flow chart of a method for accurately picking up a pull tab of a cigarette gift box according to 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-manipulator, 41-suction nozzle, 42-manipulator arm, 43-rotating motor, 44-lateral mounting plate, 45-mounting slot, 46-air pipe, 47-air flow conversion valve, 48-positive pressure air pipe, 49-negative pressure air pipe, 5-cigarette gift box, 6-manipulator controller, 7-switch, 8-pull tongue. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0047] Embodiment 1: A method for accurately picking up a pull tab of a cigarette gift box, which is used to pull up the pull tab in a cigarette gift box 5 and pull it to the outer end of the gift box on a production conveyor line of a gift box cigarette packaging machine, comprising 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 an image of the cigarette gift box 5 directly below and acquires image data. The image acquisition station has a stereoscopic imaging function, based on which the height position information of the tongue tip can be obtained.

[0049] Step S2, establish a coordinate system based on the position of the image acquisition station, 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 determine that the current position information of the pull tab in the coordinate system includes the horizontal position information and 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 tilted too high.

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

[0051] Step S4, based on the comparison between the current position information and the standard coordinate information of the qualified pull tab, the posture error is calculated, if the posture error is greater than a preset value, it is judged as the pull tab offset, and the offset coordinate difference corresponding to the posture error is obtained;

[0052] Step S5, when the cigarette gift box 5 arrives at the suction station of the robot 4, the robot 4 is in the standard position. If the posture error does not exceed the preset value, the robot 4 performs a standardized action; if the posture error exceeds the preset value, the robot 4 performs a displacement compensation movement correction based on the offset coordinate difference, executes the subsequent action of moving the suction nozzle 41 downward, sucking the pull tab and moving it into place.

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

[0054] The image data in the cigarette gift box 5 is obtained, and the image is filtered and denoised using a Gaussian filter or a median filter to avoid the influence of noise on shadow edge detection, and the image is converted into a grayscale image for shadow edge detection. Because edge detection is mainly determined by color mutations, color information is not required. Converting the image into a grayscale image can reduce 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 often used.

[0055] By convolving the image, the gradient size and direction of each pixel are calculated, and the gradient size of the pixel is calculated for edge detection; by calculating the gradient size of the pixel for edge detection, the image can be convolved using Sobel, Prewitt, Robert, Laplace and other operators to calculate the gradient size and direction of each pixel.

[0056] Perform gradient thresholding on the shadow edge image, set a high threshold and a low threshold, and mark the gradient above the high threshold as a strong edge, mark the gradient below the low threshold as a non-edge, and mark the gradient above the low threshold but below the high threshold as a weak threshold. Weak edges are filtered out and only strong edges are retained. Usually, two thresholds are set, one is a high threshold and the other is a low threshold. Gradients above the high threshold are marked as strong edges, and gradients below the low threshold are marked as non-edges. Gradients above the low threshold but below the high threshold are further judged. By processing the remaining weak edges, if there are strong edge pixels around the weak edge, the weak edge is retained, otherwise it is deleted.

[0057] The shadow strength is calculated by the shadow edge strength, and a corresponding relationship is established between the pull tab end height information and the shadow strength based on the machine self-learning algorithm training, so as to obtain the pull tab end height information based on image recognition. Because the pull tab is too far away from the box surface when it is lifted, the projection is relatively virtual, which belongs to the situation of weak shadow edge strength. Therefore, the shadow edge strength is used to judge whether the pull tab is in a high position.

[0058] Preferably, the height position information of the pull tab end obtained by the image acquisition station is compared with the gift box surface. If the difference is greater than a preset value, it is determined that the pull tab is lifted too high. When the pull tab is lifted too high, the suction nozzle 41 of the manipulator 4 blows out positive pressure wind during the downward movement, stops blowing positive pressure wind after descending to a predetermined height, and switches to sucking negative pressure wind to accurately suck the pull tab end. Positive pressure wind is used only when the pull tab is lifted high. The downward blowing wind can quickly press down the end of the pull tab so that it is pressed downward on the box surface as a whole until the suction nozzle 41 approaches. The time is short and the airflow area is large, so that the pull tab end is not easy to rebound and reset and the downward pressing success rate is high.

[0059] Embodiment 2: A precise picking system for a cigarette gift box tab, applied to a production conveyor line of a gift box cigarette packaging machine, comprising:

[0060] The image acquisition station is located directly above the production conveyor line and 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 take images, and send the taken images to the robot controller 6;

[0061] The robot 4 suction station is located on the production conveyor line and is arranged after the image acquisition station. It includes the robot 4 and a suction nozzle 41. The suction nozzle 41 is arranged at the end of the robot 4 and is connected to the robot controller 6. The suction nozzle 41 can be controlled by the robot controller 6 to perform horizontal and vertical displacement, and absorb the end of the pull tab in the cigarette gift box 5, and pull it up and move it to the outside of the end of the cigarette gift box 5;

[0062] The robot controller 6 is used to receive the image sent by the image acquisition station, process and identify it, 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, convert it into a control instruction and send it to the robot 4.

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

[0064] In this embodiment, the industrial camera is a COGNEX industrial camera ISM1020-1. The industrial camera is an advanced optical instrument that can quickly and accurately obtain three-dimensional images. It has the characteristics of high precision, high speed, and strong reliability. It can obtain high-quality images under different lighting conditions and can work stably in harsh environments. The position coordinate points of the industrial camera are 700, 30, -10mm, and the coordinate axes are as follows: Figure 1As shown in the figure. The industrial camera lighting lamp uses an LED lighting lamp, which has the characteristics of high brightness, low energy consumption, and long service life. The industrial camera lighting lamp has a square structure, and the head of the industrial camera is fixed in the central position of the industrial camera lighting lamp by threads. The adjustable mounting bracket of the industrial camera lighting lamp includes an adjustable vertical mounting plate 31, a bracket mounting base 32, and a lighting lamp mounting bracket 33. Six height adjustment holes are distributed vertically on the adjustable vertical mounting plate 31, and there is a mounting hole on the bracket mounting base 32. The adjustable vertical mounting plate 31 and the bracket mounting base 32 are fixedly connected by fastening bolts. In addition, there are two threaded holes at the top of the adjustable vertical mounting plate 31 for fixing the industrial camera lighting lamp mounting bracket 33. The industrial-grade switch 7 uses a TP-LINK industrial Ethernet POE switch 7, and the product model is TL-SF1005P. The switch 7 has good equipment compatibility and strong power supply reliability. It adopts a compact aluminum alloy body, is durable, has efficient heat dissipation, and can work stably in various harsh environments. The industrial camera is connected to the industrial switch 7 through an Internet network cable. The model of the ABB manipulator 4 is IRB910SC-3 / 0.65. The manipulator 4 is not only fast and costly, but also has high precision. The repeatability accuracy is 0.01, and the path repeatability accuracy is 0.07 - 0.16 mm. The point accuracy is 0.02, and the point path accuracy is 0.21 - 0.38 mm. The ABB tongue pulling and grasping is a point motion, and the accuracy is 0.21 - 0.38. A tongue suction nozzle 41 is fixed on the ABB manipulator 4. The manipulator controller 6 is a matching device for the manipulator 4, which is used to receive the image signal collected and processed by the industrial camera and control the action of the manipulator 4 according to the image signal. Schematic installation diagram of the cigarette carton tongue precise picking system is as Figure 2 . To achieve the purpose of precise picking of the carton tongue, the industrial camera is connected to the switch 7 through an Ethernet cable. The switch 7 and the controller transfer data through an Ethernet cable. The controller and the ABB manipulator 4 are connected through a communication cable. The industrial camera reads and processes the image signal of the gift box on the conveying channel through visual detection, and transmits its signal to the ABB manipulator controller 6 through the switch 7. The controller locates the tongue through an algorithm, calculates the pose error, and further controls the ABB manipulator 4 to precisely pick up the tongue. Visual positioning of the manipulator 4 picking up the tongue is as Figure 3 , Figure 4 , Figure 5 , Figure 6 shown.

[0065] Preferably, the end of the manipulator 4 includes a robotic arm rod 42 and a rotating motor 43 installed at the bottom end of the robotic arm rod 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. An installation groove 45 is provided at the end of the mounting plate. The suction nozzle 41 is arranged vertically, and the tail end of the suction nozzle 41 is installed in the installation groove 45. The suction nozzle 41 is connected to the air pipe 46. When the end position of the pull tab is close to the edge of the cigarette gift box 5, the manipulator 4 can make the suction nozzle 41 contact the end position of the pull tab by controlling the rotation of the mounting plate, 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 connection schematic diagram between the rotating motor 43 and the mounting plate is not given; however, the transmission technology for the rotating motor 43 to drive the plate to rotate is already in the prior art, so the specific structural details will not be elaborated.

[0066] Preferably, the camera adjustable mounting bracket 3 includes an adjustable vertical mounting plate 31, a bracket mounting base 32, and a lighting lamp mounting bracket 33. A number of height adjustment holes are distributed along the vertical direction on the adjustable vertical mounting plate 31, and there is a mounting hole on the bracket mounting base 32. The adjustable vertical mounting plate 31 and the bracket mounting base 32 are fixedly connected by a fastening bolt passing through the mounting hole and the height adjustment hole. There are two threaded holes at the top of the adjustable vertical mounting plate 31 for installing and fixing the industrial camera 2 and the lighting lamp.

[0067] Preferably, the suction nozzle 41 of the manipulator 4 is connected to the air flow conversion valve 47 through the air pipe 46. The air flow conversion valve 47 is connected to the manipulator controller 6. The manipulator controller 6 can control the on-off of the positive and negative pressure air flows of the air flow conversion valve 47, so that the air pipe 46 can emit air from the air nozzle when necessary and be in a negative pressure for sucking the pull tab inward when sucking. Therefore, the air flow conversion valve 47 is respectively connected to the positive pressure air pipe 48 and the negative pressure air pipe 49, and can realize the switching between positive and negative air flows. The air flow conversion valve 47 can control the positive pressure air flow to pass through and flow out from the suction nozzle 41, and can also stop the blowing of the positive pressure air flow and turn to suck the negative pressure air flow to realize the adsorption function of the suction nozzle 41. The air flow conversion valve 47 is a commercially available product. One end of the air flow conversion valve 47 is simultaneously connected to the positive pressure air pipe 48 and the negative pressure air pipe 49, and the other end is directly connected to the air pipe 46. The air pipe 46 is connected to the suction nozzle 41 on the manipulator 4. When the air flow conversion valve 47 controls the connection of the positive pressure air flow, the negative pressure suction is stopped. When the negative pressure suction is performed, the connection of the positive pressure air flow is stopped, and the negative pressure air pipe 49 is connected. The suction nozzle 41 can be used for two purposes, ensuring the accuracy of the air flow direction, and the downward pressing of the pull tab can be fast, accurate and stable.

[0068] It should be understood that the above specific embodiments of the present invention are only used for illustrative explanation or interpretation of the principles of the present invention, and do not constitute a limitation on the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall 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 a pull tab of a cigarette gift box, characterized in that: The method is used for pulling up a pull tab in a cigarette gift box (5) on a production conveyor line of a gift box cigarette packaging machine and pulling the pull tab to the outer end of the gift box, comprising the following steps: Step S1: The cigarette gift box (5) is transported on the production conveyor line and arrives at the image acquisition station. The industrial camera (2) takes an image of the cigarette gift box (5) directly below and acquires image data. Step S2, establishing a coordinate system based on the position of the image acquisition station, and determining standard coordinate information of a qualified pull tab in the coordinate system; Step S3, performing visual recognition processing on the image data, taking the pull tab in the cigarette gift box (5) as the recognition object, and determining the current position information of the pull tab in the coordinate system; Step S4, based on the comparison between the current position information and the standard coordinate information of the qualified pull tab, the posture error is calculated, if the posture error is greater than a preset value, it is judged as the pull tab offset, and the offset coordinate difference corresponding to the posture error is obtained; Step S5, when the cigarette gift box (5) arrives at the suction station of the robot (4), the robot (4) is in a standard position. If the posture error does not exceed the preset value, the robot (4) performs a standardized action; if the posture error exceeds the preset value, the robot (4) performs a displacement compensation movement correction based on the offset coordinate difference, and executes the subsequent action of moving the suction nozzle (41) downward, sucking the pull tab and moving it into place.

2. The accurate picking method of the cigarette gift box pull tab according to claim 1 is characterized in that: Step S3 includes: the coordinate system is a three-dimensional coordinate system, and determining that 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) by more than a height threshold, it is determined that the pull tab is tilted too high.

3. The accurate picking method of the cigarette gift box pull tab according to claim 2 is characterized in that: The image acquisition station has a stereoscopic imaging function, based on which the height position information of the tongue tip can be obtained.

4. The accurate picking method of the cigarette gift box pull tab according to claim 2 is characterized in that: The height position information of the tongue tip is obtained by processing an image acquired by an industrial camera (2), comprising the following steps: Obtain image data in the cigarette gift box (5), use Gaussian filtering or median filtering to filter and reduce noise on the image to 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 size and direction of each pixel are calculated, and the gradient size of the pixel is calculated for edge detection; Perform gradient thresholding on the shadow edge image, set a high threshold and a low threshold, and mark the gradient above the high threshold as a strong edge, the gradient below the low threshold as a non-edge, and the gradient above the low threshold but below the high threshold as a weak threshold. The shadow intensity is inferred by the shadow edge intensity, and a corresponding relationship is established between the pull tab end height information and the shadow intensity based on machine self-learning algorithm training, so as to obtain the pull tab end height information based on image recognition.

5. The accurate picking method of the cigarette gift box pull tab according to claim 3 or 4, characterized in that: The height position information of the pull tab end obtained by the image acquisition station is compared with the gift box surface. If the difference is greater than a preset value, it is determined that the pull tab is lifted too high. When the pull tab is lifted too high, the suction nozzle (41) of the robot (4) blows out positive pressure air while moving downward, stops blowing out positive pressure air after descending to a predetermined height, and switches to sucking negative pressure air to accurately suck the pull tab end.

6. A system based on the method for accurately picking up the pull tab of a cigarette gift box according to any one of claims 1 to 5, applied to the production conveyor line of a gift box cigarette packaging machine, characterized in that include: The image acquisition station is located directly above the production conveyor line and 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 an image, and send the captured image to the robot controller (6); The robot (4) suction station is located on the production conveyor line and is arranged after the image acquisition station. It includes the robot (4) and a suction nozzle (41). The suction nozzle (41) is arranged at the end of the robot (4) and is connected to the robot controller (6). The suction nozzle (41) can be controlled by the robot controller (6) to move horizontally and vertically, and absorb the end of the pull tab in the cigarette gift box (5), and pull it up and move it to the outside of the end of the cigarette gift box (5); The robot controller (6) is used to receive the image sent by the image acquisition station, process and identify it, determine the position information of the end of the pull tab in the current cigarette gift box (5), and calculate the operation path of the robot (4) to convert it into a control instruction and send it to the robot (4).

7. The precise picking system for the pull tab of a cigarette gift box according to claim 6, characterized in that: The invention 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) and the robot controller (6) transmit data via the Ethernet cable, and the robot controller (6) is connected to the robot (4) via a communication cable.

8. According to the precise picking system of the pull tab of the cigarette gift box according to claim 6, the end of the manipulator (4) comprises a manipulator arm (42) and a rotating motor (43) installed at the bottom end of the manipulator arm (42), a transverse mounting plate (44) is connected to the output end of the rotating motor (43), the rotating motor (43) can drive the transverse 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 end of the pull tab is close to the edge of the cigarette gift box (5), the robot (4) controls the rotation of the mounting plate so that the suction nozzle (41) can contact the end of the pull tab.

9. According to the precise picking system for the pull tab of a cigarette gift box as described in claim 6, the adjustable camera mounting bracket (3) includes an adjustable vertical mounting plate (31), a bracket mounting base (32), and a lighting fixture mounting bracket (33); the adjustable vertical mounting plate (31) has a plurality of height adjustment holes distributed in 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 holes and the height adjustment holes; the adjustable vertical mounting plate (31) has two threaded holes on the top for mounting and fixing the industrial camera (2) and the lighting fixture.

10. According to the precise picking system for the pull tab of a cigarette gift box as described in claim 6, the suction nozzle (41) of the manipulator (4) is connected to the air flow conversion valve (47) through the air pipe (46), and the air flow conversion valve (47) is respectively connected to the positive pressure air pipe (48) and the negative pressure air pipe (49), so as to realize the switching between positive and negative airflows; the air flow conversion valve (47) can control the positive pressure airflow to pass through and flow out from the suction nozzle (41), and can also stop the positive pressure airflow from blowing out and inhale the negative pressure airflow instead, so as to realize the adsorption function of the suction nozzle (41).

Images