A flying laser marking system and a marking method

Abstract

The application discloses a kind of flight laser marking system and flight laser marking method, it is related to laser marking technical field.Flight laser marking system includes feeding mechanism, conveying mechanism, marking visual positioning module, laser marking machine, visual detection and positioning module, defective product rejection mechanism, discharging mechanism, sensing module and main control and data processing system;Conveying mechanism includes product support belt and synchronous belt, sensing module includes encoder and light reflection sensor;Product support belt adopts longitudinal groove array structure or single / multiple horizontal groove structure.The method includes the steps of feeding control, visual positioning before marking, Y-axis coordinate calibration compensation, visual quality detection after marking, defective product rejection, discharging control and the like.The present application realizes continuous, fully automated production, and the production efficiency is greatly improved compared with static marking, and the marking precision is guaranteed through visual positioning and compensation technology, and online quality control and defective product rejection of product are realized.

Description

Technical Field

[0001] This invention relates to the technical field of laser marking machines, and in particular to a flying laser marking system and marking method. Background Technology

[0002] Laser marking machines use laser beams to create permanent marks on the surfaces of various materials: when a laser beam irradiates the surface of the material being processed, the material absorbs the laser energy, and a thermal excitation reaction occurs in the irradiated area, causing the surface (or coating) temperature to rise, resulting in physical and chemical changes such as deformation, melting, ablation, and vaporization, ultimately forming a permanent mark.

[0003] Currently, laser marking technology has been widely applied in various manufacturing scenarios. With the manufacturing industry moving towards automation and efficiency, flying laser marking technology has emerged, enabling marking to be completed during product movement without interruption, significantly improving production efficiency. However, existing flying laser marking systems still have some shortcomings: First, marking accuracy is difficult to guarantee, as product movement may cause positional shifts or timing belt oscillations, leading to inaccurate marking positions; second, there is a lack of effective online quality inspection and defective product rejection mechanisms, making 100% quality control impossible; and third, the coordination between material loading, marking, and inspection is poor, and the level of automation needs improvement.

[0004] In view of this, the present invention conducts in-depth research on the various defects and pain points caused by the imperfections in the design of existing flight marking equipment. Through optimizing the structural design, improving the working principle and repeatedly verifying through experiments, the present invention was finally developed. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a flying laser marking system and method that can achieve fully automatic flying marking and avoid marking position deviation and missing marking.

[0006] To achieve the above objectives, the solution of the present invention is:

[0007] A flying laser marking system includes a feeding mechanism, a conveying mechanism, a marking vision positioning module, a laser marking machine, a vision inspection and positioning module, a defective product rejection mechanism, a feeding mechanism, a sensing module, and a main control and data processing system. The marking vision positioning module, the laser marking machine, the vision inspection and positioning module, the defective product rejection mechanism, and the sensing module are respectively connected to the main control and data processing system.

[0008] The feeding mechanism is located at the starting end of the conveying mechanism or on one side of the conveying mechanism upstream of the marking vision positioning module, and transfers the product from the feeding mechanism to the conveying mechanism.

[0009] The conveying mechanism includes a timing belt and a product support belt. The product support belt is installed on the timing belt to carry the products to be passed sequentially through the marking vision positioning module, the laser marking machine, the vision inspection and positioning module, and the defective product rejection mechanism.

[0010] The sensing module includes a light reflection sensor and an encoder. The encoder is connected to the drive mechanism of the synchronous belt to collect the speed of the synchronous belt and the X-axis coordinate information in real time. The light reflection sensor is installed upstream of the feeding area and / or the defective product rejection area of ​​the product support belt.

[0011] The marking vision positioning module is located upstream of the laser marking machine and includes a first industrial camera and a first vision processing unit. The first industrial camera is used to capture images of the moving product to be marked and to obtain the positioning coordinates and rotation angle information of the product to be marked. The first industrial camera is connected to the main control and data processing system. The first vision processing unit processes the images captured by the first industrial camera and calculates the current positioning coordinates and rotation angle of the product to be marked.

[0012] The laser marking machine is used to laser mark the product to be marked according to the instructions of the main control and data processing system. It includes a galvanometer assembly, which is electrically connected to the main control and data processing system. The deflection angle is adjusted in real time according to the positioning coordinates and rotation angle of the product, so that the laser beam can accurately act on the target marking position of the product.

[0013] The vision inspection and positioning module is located downstream of the laser marking machine to determine whether the marking quality of the product is up to standard; the judgment result is sent to the main control and data processing system.

[0014] The defective product rejection mechanism is used to reject products that are judged to be defective according to instructions from the main control and data processing system.

[0015] The feeding mechanism is used to feed qualified marked products.

[0016] The main control and data processing system calculates the Y-axis compensation value based on the detection data from the vision inspection and positioning module, and corrects the marking coordinates of the next product to be marked; the specific steps of Y-axis coordinate calibration and compensation include:

[0017] S41. The marking vision positioning module captures the positioning coordinates (A1, B1) of product 1 and records the capture time as T1. The main control and data processing system calculates the compensation distance Lmove1 = (Tmarking1 - T1) × V based on the marking time Tmarking1 and the synchronous belt speed V of product 1, and determines the marking coordinates of product 1 by the laser marking machine as (A1 + Lmove1, B1).

[0018] S42. The visual inspection and positioning module captures the positioning coordinates (C1, D1) of product 1 to obtain the actual position information of product 1 after marking.

[0019] S43, the visual detection and positioning module shoots the positioning coordinates (A2, B2) of the product 2, records the shooting time as T2, the main control and data processing system calculates the compensation distance Lmove2= (Tmark2-T2) x V, and determines the initial marking coordinates of the product 2 for the laser marking machine as (A2+Lmove2, B2), wherein Tmark2 is the marking time of the product 2;

[0020] S44, the approximate triangular model is used to calculate X1=Lmove2x[(D1-B1) / (C1-A1)], wherein X1 is the deviation estimation value in the Y axis direction;

[0021] S45, the correction amount K is set, and the Y axis coordinate compensation value is finally calculated as X1+K;

[0022] S46, the actual marking coordinates of the product 2 are corrected as (A2+Lmove2, B2+Ycompensation).

[0023] Further, the upstream of the marking visual positioning module is further provided with a material stacking prevention mechanism, the material stacking prevention mechanism comprises a soft brush arranged in an inclined manner, the soft brush is arranged above the product supporting belt and corresponds to the placing position of the product; a product storage box is arranged at the bottom of the end of the conveying direction of the synchronous belt, and a material jam prevention mechanism is further arranged between the end of the synchronous belt and the product storage box.

[0024] Further, the product supporting belt is a longitudinal groove array structure, the encoder is connected with the driving mechanism of the synchronous belt to collect the motion speed and position information of the synchronous belt in real time, the defective product removing mechanism adopts a blowing module, the blowing module is installed on one side of the synchronous belt, and a defective product storage box is arranged on the opposite side of the blowing module, so that the blowing module blows the defective product into the defective product storage box through the jet airflow.

[0025] Further, the product supporting belt is a single or multiple transverse groove structure; the defective product removing mechanism comprises a rotating arm rotating by 180 degrees, the two ends of the rotating arm are provided with suction cups, and a defective product storage box is arranged on one side of the conveying mechanism within the rotation range of the rotating arm.

[0026] The feeding mechanism comprises a vibrating disc, a straight vibration guide rail and a rotating arm, the straight vibration guide rail is arranged at the discharge port of the vibrating disc, the straight vibration guide rail has a guide groove corresponding to the length or width or diameter of the product, the middle position of the rotating arm is connected with a rotating cylinder, and one suction cup is arranged at each of the left and right ends of the rotating arm, wherein one suction cup is located at the position above the guide groove of the straight vibration guide rail, and the other suction cup corresponds to the conveying mechanism.

[0027] The application can also adopt the following technical solutions:

[0028] A flight laser marking method based on the flight laser marking system, comprising the following steps:

[0029] S1, loading control: the product is delivered to the moving product supporting belt through the loading mechanism, and the main control and data processing system controls the feeding time of the loading mechanism according to the detection signal of the light reflection sensor;

[0030] S2, vision positioning before marking: the vision detection and positioning module photographs the moving product and obtains the product positioning coordinates and rotation angle information, the encoder collects the synchronous belt position information, and the main control and data processing system fuses the above information to calculate the marking trigger time and marking coordinates;

[0031] S3, laser marking: when the marking trigger time is reached, the main control and data processing system controls the laser marking machine to adjust the deflection angle of the galvanometer and performs laser marking on the product;

[0032] S4, Y-axis coordinate calibration compensation: the Y-axis compensation value is calculated according to the detection data of the vision detection and positioning module and the vision detection and positioning module, and the marking coordinates of the subsequent product are corrected; the specific steps of Y-axis coordinate calibration compensation include:

[0033] S41, the vision positioning module photographs the positioning coordinates (A1, B1) of product 1, records the photographing time as T1, and the main control and data processing system calculates the compensation distance Lmove1= (Tmarking1-T1) x V according to the marking time Tmarking1 of product 1 and the synchronous belt speed V, and determines the marking coordinates of product 1 by the laser marking machine as (A1+Lmove1, B1);

[0034] S42, the vision detection and positioning module photographs the positioning coordinates (C1, D1) of product 1, and obtains the actual position information of product 1 after marking;

[0035] S43, the vision detection and positioning module photographs the positioning coordinates (A2, B2) of product 2, records the photographing time as T2, and the main control and data processing system calculates the compensation distance Lmove2= (Tmarking2-T2) x V, and determines the initial marking coordinates of product 2 by the laser marking machine as (A2+Lmove2, B2), wherein Tmarking2 is the marking time of product 2;

[0036] S44, the approximate triangle model is used to calculate X1=Lmove2x[(D1-B1) / (C1-A1)], wherein X1 is the deviation estimation value in the Y-axis direction;

[0037] S45, the correction amount K is set, and the Y-axis coordinate compensation value X1+K is finally calculated;

[0038] S46, the actual marking coordinates of product 2 are corrected to (A2+Lmove2, B2+Ycompensation);

[0039] S5, visual quality detection after marking: the visual detection and positioning module photographs the product after marking and determines the marking quality, and coordinates the positioning of defective products;

[0040] S6, defective product rejection: the main control and data processing system calculates and controls the defective product rejection mechanism to reject defective products;

[0041] S7, product unloading: the products that pass the visual detection and positioning module inspection are unloaded through the unloading mechanism.

[0042] Further, in step S1, the feeding mechanism has a rotating arm, the middle part of the rotating arm is connected with a rotating cylinder, and the left and right ends of the rotating arm are respectively provided with a suction cup. The conveying mechanism has a synchronous belt, and the synchronous belt has a plurality of product supporting belts arranged at equal intervals in the longitudinal direction. The conveying direction of the synchronous belt is transverse, and a groove is formed between adjacent product supporting belts. Each groove corresponds to a falling edge and a rising edge. A light reflection sensor is arranged on one side of the synchronous belt within the stroke range of the rotating arm. The specific steps of the feeding control are as follows:

[0043] The light reflection sensor continuously detects the falling edge of the groove, and the time to trigger the product release is Ti+t cycle, wherein Ti is the time when the light reflection sensor detects the falling edge, t cycle is the time when the synchronous belt moves one groove interval, and i=1, 2, 3, …; After the product on the rotating arm is in place, the actual triggering time is Tn+t cycle, and Tn is the time when the light reflection sensor detects the first falling edge after the rotating arm is in place.

[0044] Further, in step S2, the visual positioning before marking specifically includes:

[0045] S21, when the product passes through the detection area, the first industrial camera is triggered to take a picture or take a picture at a certain time under the control of the main control and data processing system. The photographing period is matched with the synchronous belt movement speed to ensure that each product is photographed at least once;

[0046] S22, the first visual processing unit processes the image collected by the first industrial camera to calculate the current coordinates (X1, Y1, θ1) of the product, wherein θ1 is the rotation angle. At the same time, the encoder collects the X-direction coordinate information of the synchronous belt in real time, and sends them to the main control and data processing system;

[0047] S23, the main control and data processing system fuse the product positioning coordinates, the synchronous belt position information and the effective marking area information of the laser marking machine to determine whether the product center coordinates fall within the marking center area. If the product center coordinates are within the marking center area, calculate the marking trigger time and marking coordinates, and the marking trigger time=T1+delay time, wherein T1 is the photographing time of the visual detection and positioning module, and the delay time is calculated according to the synchronous belt speed and the distance of the product to the marking position.

[0048] S24, the calculated marking trigger time and marking coordinates are stored in the marking information queue, the marking information queue uses a first-in first-out way to store, when the marking task in the queue reaches the trigger time, it is executed in order.

[0049] Further, the effective marking area of the laser marking machine includes a marking maximum area and a marking center area, the marking maximum area coordinates are (0-w / 2, 0-h / 2, w, h), the marking center area coordinates are (0-w / 2+r, 0-h / 2+r, w-2r, h-2r), wherein w is the marking area width, h is the marking area height, and r is the maximum radius of the product; the main control and data processing system judges whether the product center coordinates fall in the marking center area, only the product in the area will be marked;

[0050] When the marking task in the marking information queue reaches the preset marking trigger time, the main control and data processing system sends a marking instruction to the laser marking machine, the galvanometer assembly of the laser marking machine adjusts the deflection angle in real time according to the received marking coordinates and rotation angle information, so that the laser beam accurately acts on the target marking position of the product, and the laser marking machine emits laser to mark the product, and completes the marking action.

[0051] Further, the flying laser marking method further includes a data recording step, the main control and data processing system record the marking time, marking coordinates, compensation value, quality detection result and rejection state information of each product, and realize the whole-process traceability of product quality.

[0052] After the above scheme is adopted, the flying laser marking system and marking method have the following beneficial effects:

[0053] Full automation: the system integrates product loading, positioning, marking, detection, defective product rejection and good product unloading, and each link cooperates, without manual intervention, which greatly reduces labor cost, avoids errors caused by manual operation, and improves production stability.

[0054] High efficiency: the product completes all processes such as loading, marking, detection, rejection and unloading during the movement process, without stopping in the middle, realizes real continuous production, and the production efficiency is several times higher than that of static marking, which can meet the demand of large-scale production.

[0055] Online quality control: the present application carries out quality detection on each product after marking through the marking visual detection and positioning module, can identify defective products online, and realizes defective product elimination through the defective product elimination mechanism, ensures that the quality of the products leaving the factory is qualified; at the same time, the main control and data processing system records the quality information of each product, realizes the whole-process traceability of product quality, and facilitates quality control. The present application ensures the reliable marking quality of each product while marking at high speed.

[0056] High precision: the present application obtains accurate position information of the product through the marking visual positioning module, combines the motion data of the synchronous belt collected by the encoder, can accurately calculate the marking trigger time and marking coordinates; at the same time, through the Y-axis coordinate calibration compensation method, the marking deviation caused by the swing of the synchronous belt is effectively corrected, even in the high-speed motion state, the position precision of marking can be ensured, and the demand of high-precision marking is met.

[0057] Strong adaptability: the present application provides two product supporting belt structure schemes and corresponding feeding and elimination methods, can adapt to the marking needs of different specifications and different types of products, and has wide application range. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 The figure is a block diagram of the flight laser marking system of the present application.

[0059] Figure 2 The figure is a perspective view of the first embodiment of the flight laser marking system of the present application.

[0060] Figure 3 The figure is a front view of the first embodiment of the flight laser marking system of the present application.

[0061] Figure 4 The figure is a top view of the first embodiment of the flight laser marking system of the present application.

[0062] Figure 5 The figure is a side view of the first embodiment of the flight laser marking system of the present application.

[0063] Figure 6 The figure is a perspective view of the second embodiment of the flight laser marking system of the present application.

[0064] Figure 7 The figure is a front view of the second embodiment of the flight laser marking system of the present application.

[0065] Figure 8 The figure is a perspective view of the third embodiment of the flight laser marking system of the present application.

[0066] Figure 9 The figure is a front view of the third embodiment of the flight laser marking system of the present application.

[0067] Figure 10 The feeding principle schematic view of the third embodiment of the flying laser marking system of the present application.

[0068] Figure 11 The Y-axis coordinate calibration compensation schematic view of the product marking of the present application.

[0069] Figure 12 The coordinate compensation triangle model schematic view of the marking Y-axis direction of the present application.

[0070] Label explanation:

[0071] 10, feeding mechanism; 11, vibration disc; 12, straight vibration guide rail; 121, guide groove; 13, rotating arm; 14, rotating cylinder; 15, suction cup; 16, anti-stacking mechanism; 20, conveying mechanism; 21, synchronous belt; 22, product supporting belt; 23, groove; 30, marking visual positioning module; 40, laser marking machine; 50, visual detection and positioning module; 60, defective product removing mechanism; 61, air blowing module; 62, defective product storage box; 70, discharging mechanism; 71, product storage box; 72, anti-jamming mechanism; 80, sensing module; 81, light reflection sensor; 82, encoder; 90, main control and data processing system. DETAILED DESCRIPTION

[0072] In order to further explain the technical scheme of the present application, the present application will be described in detail below through specific embodiments.

[0073] As shown in Figures 1 to 9 , the present application discloses a flying laser marking system, which comprises a feeding mechanism 10, a conveying mechanism 20, a marking visual positioning module 30, a laser marking machine 40, a visual detection and positioning module 50, a defective product removing mechanism 60, a discharging mechanism 70, a sensing module 80, and a main control and data processing system 90. The feeding mechanism 10, the conveying mechanism 20, the marking visual positioning module 30, the laser marking machine 40, the visual detection and positioning module 50, the defective product removing mechanism 60, and the sensing module 80 are respectively connected to the main control and data processing system 90.

[0074] The feeding mechanism 10 is arranged at the starting end of the conveying mechanism 20 or on one side of the conveying mechanism 20 upstream of the marking visual positioning module 30, and moves the product from the feeding mechanism 10 to the conveying mechanism 20. The feeding mechanism 10 can adopt various feeding modes, such as conveying belt butt joint, elevator, vibration disc, feeding robot, etc. As shown in the first embodiment of Figures 2 to 5 and the second embodiment of Figure 6 , Figure 7In the second embodiment shown, the feeding mechanism 10 uses a vibratory feeder 11 and a linear vibratory guide rail 12. The pre-marked products are placed in the vibratory feeder 11. The vibratory feeder 11 uses electromagnetic vibration to generate directional micro-amplitude reciprocating motion. Combined with the inclination and structural design of the vibratory feeder channel, the products are arranged in an orderly manner along a predetermined trajectory and conveyed to the linear vibratory guide rail 12. The linear vibratory guide rail 12 has guide grooves 121 that correspond to the length, width or diameter of the products. After the products are discharged from the outlet of the vibratory feeder 11, they fall one by one into the guide grooves 121 of the linear vibratory guide rail 12, avoiding multiple products from entering the conveying mechanism 20 at the same time.

[0075] like Figures 8 to 10 The third embodiment shown adds a rotating arm 13 to the first and second embodiments. A rotating cylinder 14 is connected to the middle of the rotating arm 13. A suction cup 15 is provided at each of the left and right ends of the rotating arm 13. The conveying mechanism 20 has a synchronous belt 21 with multiple product support belts 22 arranged longitudinally at equal intervals. The conveying direction of the synchronous belt 21 is transverse. A groove 23 is formed between adjacent product support belts 22. Each groove 23 corresponds to a falling edge and a rising edge. The sensing module 80 has a light reflection sensor 81. A light reflection sensor 81 is provided on one side of the synchronous belt 21 within the stroke range of the rotating arm 13. In this embodiment, the light reflection sensor 81 is used to detect the time of each falling edge of the conveying mechanism 20 (Ti / Tn, i / n=1, 2, 3, ..., continuous detection, Ti is the proposed trigger time, and Tn is the actual trigger time).

[0076] The vibratory feeder 11 and the linear guide rail 12 arrange the products into an orderly queue, ensuring that the rotating arm 13 can stably grasp them. The suction cups 15 at both ends of the rotating arm 13 are rotated and interchanged by the rotating cylinder 14. One suction cup 15 is located at the linear guide rail 12, and the other suction cup corresponds to the conveying mechanism 20. The rotating arm 13 completes the actions of picking up, transferring, and releasing the material, and the suction force of the suction cups 15 is used to achieve non-destructive grasping of the product. The light reflection sensor 81 set in the conveying mechanism 20 detects the position of the product when it is placed into the conveying mechanism 20, and sets the distance between the suction cup position and the light reflection sensor 81 as the distance between adjacent grooves 23. Combined with the trigger logic of "t + cycle", where "cycle" in "t + cycle" is the time interval between two adjacent grooves 23 of the support belt passing through the light reflection sensor 81, it ensures that the product is placed in the groove 23 position of the support belt 22 of the conveying mechanism 20.

[0077] The specific feeding action of the third embodiment is as follows: the product is placed in the vibrating disc 11, the vibrating disc 11 vibrates and arranges the product, and the product is output from the straight vibrating guide rail 12 to wait for the suction cup 15 of the rotating arm 13 to grab; the suction cup 15 at one end of the rotating arm 13 moves to the straight vibrating guide rail 12 and adsorbs one product, at this time, the suction cup 15 at the other end is at the feeding position of the transmission mechanism 20; the rotating cylinder 14 drives the rotating arm 13 to rotate, and the suction cup 15 adsorbing the product is rotated to above the conveying mechanism 20, the light reflection sensor 81 detects the “falling edge time” of the conveying mechanism 20, and combines the “t+period” of the approximate trigger time (Ti, i=1, 2, 3, …, continuous detection) to predict the feeding time; when the product on the rotating arm 13 is completely matched with the position of the conveying mechanism 20, the light reflection sensor 81 detects the falling edge time again, combines the actual trigger time of “t+period”, the suction cup 15 releases the product and accurately places it on the groove 23 of the supporting belt 22 of the conveying mechanism 20, and the suction cup 15 at the other end takes the product from the straight vibrating guide rail 12 again, the rotating arm 13 rotates to feed, and the above process is repeated to realize continuous feeding.

[0078] In order to avoid the product from being stacked together during feeding of the feeding mechanism 10, the anti-stacking mechanism 16 is arranged upstream of the marking visual positioning module 30. Figures 2 to 10 In the three embodiments shown, the anti-stacking mechanism 16 includes two soft brushes arranged at an interval and inclined, and the soft brushes are arranged above the product supporting belt 22 and correspond to the placement position of the product.

[0079] The conveying mechanism 20 includes a synchronous belt 21 and a product supporting belt 22, and the product supporting belt 22 is used to carry the product to be marked and the marked product. The application provides two structural schemes, i.e., the product supporting belt 22 of the first embodiment ( Figures 2 to 5 ) and the product supporting belt 22 of the second embodiment ( Figure 6 ). The product supporting belt 22 of the first embodiment and the second embodiment is a single or multiple transverse groove 23 structure, which is suitable for transporting products of different specifications. Figure 7 The product supporting belt 22 of the third embodiment ( Figures 8 to 10 ) is an array structure with longitudinal grooves 23. The groove 23 is arranged to accommodate the protruding part below the product to be marked, so as to ensure the horizontal surface of the product to be marked.

[0080] The sensing module 80 at least includes an encoder 82 connected to the driving mechanism of the synchronous belt 21, to collect the synchronous belt 21 movement speed and X direction coordinate information in real time, to provide accurate movement parameter support for the calculation of the marking trigger time and the rejection trigger time. The sensing module 80 is further provided with a light reflection sensor 81 according to actual needs, which can be installed on the upstream of the product supporting belt 22 in the loading area and the defective product rejection area. The light reflection sensor 81 in the loading area is used to detect the position signal of the groove 23 (such as embodiment three), to provide the loading mechanism 10 discharge time reference for the main control and data processing system 90; the light reflection sensor 81 upstream of the defective product rejection area is used to detect the falling edge of the groove 23, to provide the basis for the calibration of the defective product rejection trigger time.

[0081] The marking visual positioning module 30 is arranged upstream of the laser marking machine 40, and includes a first industrial camera and a first visual processing unit. The first industrial camera is used to shoot the moving product and obtain the positioning coordinates and rotation angle information of the product. The first industrial camera is controlled by the main control and data processing system 90, and can adopt the triggered shooting or the timed shooting mode. The shooting period is matched with the synchronous belt 21 movement speed, to ensure that each product is at least shot once and complete positioning information is obtained. The first visual processing unit can quickly and accurately calculate the current accurate coordinates (X1, Y1, θ1) of the product through advanced image processing technologies such as template matching and Blob analysis, wherein θ1 is the rotation angle, to provide data support for the subsequent accurate marking.

[0082] The working process of the marking visual positioning module 30 is as follows:

[0083] Firstly, the product enters the shooting range of the first industrial camera of the marking visual positioning module 30;

[0084] Then, the first industrial camera triggers the shooting or the timed shooting;

[0085] Next, the first visual processing unit analyzes and quickly calculates the current accurate position coordinates (X1, Y1, θ1) of the product according to the shot picture;

[0086] After that, the encoder 82 obtains the X axis direction coordinate information of the synchronous belt 21 in real time and sends it to the main control and data processing system 90;

[0087] Finally, the main control and data processing system 90 fuses the product position coordinates, the synchronous belt 21 position information and the effective marking area information of the laser marking machine 40, to judge whether the product center coordinates fall in the marking center area. If yes, the marking trigger time and the marking coordinates are calculated and stored in the marking information queue.

[0088] The marking trigger time is equal to Ta plus a delay time, wherein Ta is the shooting time of the marking visual positioning module 30, and the delay time is calculated according to the speed of the synchronous belt 21 and the distance from the product to the marking position; the marking information queue stores the marking trigger time and the marking coordinates in a first-in first-out manner, and when the marking task in the queue reaches the trigger time, it is executed in order.

[0089] The laser marking machine 40 is used for laser marking of the product according to the instruction of the master and data processing system 90, which includes a galvanometer assembly electrically connected with the master and data processing system 90, capable of adjusting the deflection angle in real time according to the positioning coordinates and the rotation angle of the product, to ensure that the laser beam accurately acts on the target marking position of the product.

[0090] The effective marking area of the laser marking machine 40 includes a marking maximum area and a marking center area, the coordinates of the marking maximum area are (0-w / 2, 0-h / 2, w, h), and the coordinates of the marking center area are (0-w / 2+r, 0-h / 2+r, w-2r, h-2r), wherein w is the width of the marking area, h is the height of the marking area, and r is the maximum radius of the product. The master and data processing system 90 will judge whether the center coordinates of the product fall within the marking center area, and only the products within the area will be marked to ensure the marking effect.

[0091] When the marking task in the marking information queue reaches the preset marking trigger time, the master and data processing system 90 sends a marking instruction to the laser marking machine 40, and the galvanometer assembly of the laser marking machine 40 adjusts the deflection angle in real time according to the received marking coordinates and rotation angle information, to ensure that the laser beam accurately acts on the target marking position of the product, while the laser marking machine emits laser to mark the product, completing the marking action.

[0092] During the marking process, the master and data processing system 90 continuously receives the position information of the synchronous belt 21 sent by the encoder 82, and adjusts the marking parameters in real time to ensure that the marking process is synchronized with the motion state of the product, avoiding the marking deviation caused by the product motion.

[0093] Due to the error in the processing or installation precision of the drum of the horizontal motion driving mechanism of the synchronous belt 21, the synchronous belt 21 will appear slight forward and backward swing during rotation, causing the product to appear position deviation in the Y-axis direction, affecting the marking precision. The Y-axis swing deviation caused by the processing or installation error is systematic and stable, and will not change dramatically in the short term. Therefore, in order to avoid the position deviation of the product in the Y-axis direction, the present application also designs a Y-axis coordinate calibration compensation step, which corrects the deviation by calculating a compensation value, and uses the Y-axis tilt model of the product 1 that has completed the whole process (visual positioning-marking-visual detection) to mark the product 2.

[0094] As Figure 11 shown, the product 1 positioning coordinates photographed by the marking visual positioning module 30 are (A1, B1), and the photographing time is T1;

[0095] The product 1 marking coordinates of the laser marking machine 40 are (A1+Lmove1, B1);

[0096] The product 1 positioning coordinates photographed by the visual detection and positioning module 50 are (C1, D1);

[0097] The product 2 positioning coordinates photographed by the visual detection and positioning module 50 are (A2, B2), and the photographing time is T2;

[0098] The product 2 marking coordinates of the laser marking machine are (A2+Lmove2, B2);

[0099] Marking coordinate calibration: calculate the coordinate compensation of the marking Y axis direction, as Figure 12 shown, because the deviation angle is very small, an approximate triangle model is used to estimate X1=Lmove2×[(D1-B1) / (C1-A1)], X1 is the deviation amount caused by the Y axis inclination of the synchronous belt 21, reflecting the corresponding relationship between the "X axis movement distance" and the "Y axis deviation";

[0100] Because the Y axis inclination of the synchronous belt 21 is calculated by detecting the product 1 that has passed the visual positioning, laser marking, and visual detection three links, in order to calculate the Y axis deviation compensation of the product being marked, a correction amount K needs to be added, which can be dynamically adjusted according to the equipment running state, synchronous belt wear degree, etc. The adjustment period is a preset equipment maintenance period or once after producing a preset number of products. After adding the correction amount K, the Y axis coordinate compensation value is: Y compensation=X1+K=Lmove2×[(D1-B1) / (C1-A1)]+K;

[0101] The originally calculated marking coordinates of the product 2 are (A2+Lmove2, B2);

[0102] The actual marking coordinates of the product 2 are (A2+Lmove2, B2+Y compensation), and the marking time is T(marking);

[0103] Lmove2=(T(marking)-T2)×V, V is the speed of the synchronous belt 21.

[0104] And in the subsequent product marking coordinate calculation, the Y axis coordinate compensation value is continuously detected and calculated, and the marking Y axis coordinate compensation of the subsequent products is continuously carried out, the marking deviation caused by the synchronous belt swing is corrected in real time, and the marking precision is improved.

[0105] The vision inspection and positioning module 50 is installed downstream of the laser marking machine 40. It includes a second industrial camera and a second vision processing unit. The second industrial camera is used to capture images of the marked product and acquire the product's inspection coordinate information and marking quality information. The images captured by the industrial camera contain at least two complete product images, which can effectively prevent missed inspections and provide sufficient data for Y-axis coordinate calibration and compensation calculations.

[0106] The second vision processing unit analyzes the acquired images, using the same judgment criteria as static detection to determine whether the integrity and precision of the characters and patterns in the marking area meet the requirements, thereby determining whether the marking quality is qualified. The judgment result is then sent to the main control and data processing system 90.

[0107] The defective product rejection mechanism 60 is used to reject products with defective markings according to the instructions of the main control and data processing system 90.

[0108] like Figures 8 to 10 In the third embodiment shown, the product support belt 22 has a longitudinal groove array structure, and the defective product rejection mechanism 60 can adopt the air blowing rejection method. The air blowing module 61 is installed on one side of the synchronous belt 21, and the defective product storage box is set on the opposite side of the corresponding synchronous belt 21 and the corresponding air blowing module 61, so that the jet airflow of the air blowing module 61 blows the product directly into the defective product storage box 62.

[0109] like Figures 2 to 5 In the first embodiment shown, the product support belt 22 has a single or multiple transverse groove structure. The defective product rejection mechanism 60 adopts a rotating arm gripping rejection method. The rotating arm gripping rejection method is similar to the rotating arm structure and principle of the feeding mechanism 10. The rotating arm grips the defective products through a suction cup and transfers them to the defective product storage box 62 to ensure that the defective products are effectively rejected.

[0110] The feeding mechanism 70 can feed the marked qualified products in various ways, such as using a robot or a conveyor belt. In all embodiments of the present invention, the product storage box 71 located at the bottom of the end of the synchronous belt 21 in the conveying direction is used to directly collect the marked qualified products. To avoid product accumulation, an anti-jamming mechanism 72 is also provided at the end of the synchronous belt 21. The anti-jamming mechanism 72 prevents the material from accumulating and getting stuck in the gap between the synchronous belt 21 and the product storage box 71.

[0111] The master control and data processing system 90 is the core control unit of the flight laser marking system of the application, responsible for receiving signals of the marking visual positioning module 30, the laser marking machine 40, the visual detection and positioning module 50, the defective product removing mechanism 60, the sensing module 80 and other modules, and fusing and calculating the received data, sending control instructions and coordinating the orderly work of each module. The master control and data processing system 90 includes a marking control unit, which has a marking information queue unit adopting a first-in first-out storage mode to store information such as marking trigger time and marking coordinates of products, ensuring that the marking task is executed in order.

[0112] The master control and data processing system 90 has a built-in coordinate compensation algorithm, which can calculate the compensation value of the Y-axis direction of the product according to the detection data of the marking visual positioning module 30 and the visual detection and positioning module 50, effectively correct the marking deviation caused by the swing of the synchronous belt 21 and improve the marking precision. At the same time, the master control and data processing system 90 also has a data recording function, which can record information such as marking time, marking coordinates, compensation value, quality detection result and rejection state of each product, realizing the whole-process traceability of product quality.

[0113] The application also discloses a flight laser marking method based on the flight laser marking system.

[0114] S1, feeding control: the core of the feeding control step is to accurately and orderly deliver the products to the moving product supporting belt, and different feeding modes are adopted according to the structure of the product supporting belt.

[0115] When the product supporting belt is a longitudinal groove array structure, the rotating arm 13 with suction cups 15 at both ends is used as a feeding execution mechanism. The light reflection sensor 81 continuously detects the falling edge of the groove 23, and the master control and data processing system 90 calculates the time of triggering the product to be dropped as Ti+t period according to the detected falling edge time Ti, wherein t period is the time of moving one groove 23 interval of the synchronous belt 21, i=1, 2, 3…; after the product on the rotating arm is in place, the master control and data processing system 90 waits for the first falling edge time Tn detected by the light reflection sensor 81, and determines the actual triggering dropping time as Tn+t period, ensuring that the product can accurately fall into the groove 23.

[0116] When the product supporting belt is a single or multiple transverse groove structure, the feeding mechanism adopts a transverse vibration mechanism to directly deliver the product to the transverse groove on the synchronous belt, without complex taking and placing control, simplifying the feeding process.

[0117] S2, visual positioning before marking: the purpose of using the marking visual positioning module 30 to perform visual positioning of the product before marking is to obtain accurate position information of the product in motion, to provide data support for the calculation of marking trigger time and marking coordinates, which specifically includes:

[0118] Firstly, when the product passes through the detection area, the first industrial camera is triggered to take a picture or take a picture at a certain time under the control of the main control and data processing system 90. The shooting period is matched with the movement speed of the synchronous belt 21 to ensure that each product is at least photographed once.

[0119] Then, the first visual processing unit processes the collected images, calculates the current accurate coordinates (X1, Y1, θ1) of the product through template matching, Blob analysis and other technologies, wherein θ1 is the rotation angle, and the encoder 82 collects the X direction coordinate information of the synchronous belt 21 in real time, and sends them to the main control and data processing system.

[0120] Finally, the main control and data processing system fuses the product positioning coordinates, the synchronous belt position information and the effective marking area information of the laser marking machine to determine whether the product center coordinates fall within the marking center area. If the product center coordinates are within the marking center area, calculate the marking trigger time and the marking coordinates, the marking trigger time = T1 + delay time, wherein T1 is the shooting time of the visual detection and positioning module, and the delay time is calculated according to the synchronous belt speed and the distance from the product to the marking position; the calculated marking trigger time and marking coordinates are stored in the marking information queue, which uses the first-in first-out method for storage, and when the marking tasks in the queue reach the trigger time, it is executed in order.

[0121] S3, laser marking: when the marking task in the marking information queue reaches the preset marking trigger time, the main control and data processing system sends a marking instruction to the laser marking machine, and the galvanometer assembly of the laser marking machine adjusts the deflection angle in real time according to the received marking coordinates and rotation angle information, to ensure that the laser beam accurately acts on the target marking position of the product, and at the same time the laser marking machine emits laser to mark the product, completing the marking action.

[0122] During the marking process, the main control and data processing system continuously receives the synchronous belt position information sent by the encoder, and adjusts the marking parameters in real time to ensure that the marking process is synchronized with the product motion state, avoiding the marking deviation caused by product motion.

[0123] S4, Y-axis coordinate calibration compensation: due to the error in the machining or installation precision of the synchronous belt horizontal motion driving mechanism, the synchronous belt will appear slight forward and backward swing during rotation, resulting in position deviation of the product in the Y-axis direction, affecting the marking precision. The Y-axis coordinate calibration compensation step corrects this deviation by calculating a compensation value, which specifically includes:

[0124] First, the visual detection and positioning module shoots the positioning coordinates (A1, B1) of product 1, records the shooting time as T1, and the main control and data processing system calculates Lmove1= (Tmarking1-T1) x Vbelt speed according to the marking time Tmarking1 of product 1 and the synchronous belt speed Vbelt speed, and determines the marking coordinates of product 1 by the laser marking machine as (A1+Lmove1, B1).

[0125] Then, the visual detection and positioning module shoots the positioning coordinates (C1, D1) of product 1, and obtains the actual position information of product 1 after marking.

[0126] Next, the visual detection and positioning module shoots the positioning coordinates (A2, B2) of product 2, records the shooting time as T2, and the main control and data processing system calculates Lmove2= (Tmarking2-T2) x Vbelt speed, and determines the initial marking coordinates of product 2 by the laser marking machine as (A2+Lmove2, B2), wherein Tmarking2 is the marking time of product 2.

[0127] After that, the approximate triangle model is used to calculate X1=Lmove2x[(D1-B1) / (C1-A1)], wherein X1 is the estimated value of the deviation in the Y-axis direction; considering various error factors in the running process of the equipment, a correction amount K is set, which can be dynamically adjusted according to the running state of the equipment, the ambient temperature, and the degree of wear of the synchronous belt, and the adjustment period is a preset equipment maintenance period or once after producing a preset number of products, and the final calculated Y-axis coordinate compensation value is X1+K.

[0128] Finally, the initial marking coordinates of product 2 are corrected to (A2+Lmove2, B2+Ycompensation), and in the subsequent marking coordinate calculation of products, the Y-axis coordinate compensation value is continuously detected and calculated, and the marking Y-axis coordinate compensation of subsequent products is continuously carried out, the marking deviation caused by the swing of the synchronous belt is corrected in real time, and the marking precision is improved.

[0129] S5, visual quality detection after marking: the visual quality detection after marking step is used to judge the marking quality of the product, and provides data for Y-axis coordinate calibration compensation calculation; specifically including:

[0130] First, when the product after marking passes through the detection area of the visual detection and positioning module 50, the second industrial camera is triggered to take a picture or take a picture at a fixed time, and the resolution of the picture is not less than a preset threshold, ensuring that the characters and patterns in the marking area can be clearly identified and the integrity and precision are ensured.

[0131] Then, the second visual processing unit analyzes the collected image, adopts the same judgment standard as the static detection, and judges whether the marking quality is qualified. If the characters and patterns in the marking area are incomplete, the precision does not meet the requirements, or other defects exist, the product is determined as a defective product, and is sent to the main control and data processing system 90.

[0132] S6, defective product rejection: the core of the defective product rejection step is to reject defective products during product movement.

[0133] S7, product unloading: the products that pass the visual detection and positioning module inspection are unloaded through the unloading mechanism.

[0134] S8, data recording: during the entire marking process, the main control and data processing system 90 continuously records the marking time, marking coordinates, compensation value, quality detection result, rejection state and other information of each product, forming a product quality traceability file. When the product quality needs to be inquired, the relevant processing information of the product can be quickly obtained through the file, the product quality is fully traceable, and the quality problem can be easily investigated and solved.

[0135] The above embodiments and drawings are not limited to the product shape and style of the present application, and any appropriate changes or modifications made by those skilled in the art shall be considered as not departing from the patent scope of the present application.

Claims

1. A flying laser marking system, characterized in that: It includes a feeding mechanism, a conveying mechanism, a marking vision positioning module, a laser marking machine, a vision inspection and positioning module, a defective product rejection mechanism, a feeding mechanism, a sensing module, and a main control and data processing system. The marking vision positioning module, the laser marking machine, the vision inspection and positioning module, the defective product rejection mechanism, and the sensing module are respectively connected to the main control and data processing system. The feeding mechanism is located at the starting end of the conveying mechanism or on one side of the conveying mechanism upstream of the marking vision positioning module, and transfers the product from the feeding mechanism to the conveying mechanism. The conveying mechanism includes a timing belt and a product support belt. The product support belt is installed on the timing belt to carry the products to be marked through the marking vision positioning module, laser marking machine, vision inspection and positioning module and defective product rejection mechanism in sequence. The sensing module includes a light reflection sensor and an encoder. The encoder is connected to the drive mechanism of the synchronous belt to collect the speed of the synchronous belt and the X-axis coordinate information in real time. The light reflection sensor is installed upstream of the feeding area and / or the defective product rejection area of ​​the product support belt. The marking vision positioning module is located upstream of the laser marking machine and includes a first industrial camera and a first vision processing unit. The first industrial camera is used to capture images of the moving product to be marked and to obtain the positioning coordinates and rotation angle information of the product to be marked. The first industrial camera is connected to the main control and data processing system. The first vision processing unit processes the images captured by the first industrial camera and calculates the current positioning coordinates and rotation angle of the product to be marked. The laser marking machine is used to laser mark the product to be marked according to the instructions of the main control and data processing system. It includes a galvanometer assembly, which is electrically connected to the main control and data processing system. The deflection angle is adjusted in real time according to the positioning coordinates and rotation angle of the product, so that the laser beam can accurately act on the target marking position of the product. The vision inspection and positioning module is located downstream of the laser marking machine to determine whether the marking quality of the product is up to standard; the judgment result is sent to the main control and data processing system. The defective product rejection mechanism is used to reject products that are judged to be defective according to instructions from the main control and data processing system. The feeding mechanism is used to feed qualified marked products. The main control and data processing system calculates the Y-axis compensation value based on the detection data from the vision inspection and positioning module, and corrects the marking coordinates of the next product to be marked. The specific steps for Y-axis coordinate calibration and compensation include: S41. The marking visual positioning module captures the positioning coordinates (A1, B1) of product 1 and records the shooting time as T1. The main control and data processing system calculates the compensation distance Lmove1 = (Tmark1-T1) × V based on the marking time Tmark1 of product 1 and the synchronous belt speed V, and determines the marking coordinates of the laser marking machine for product 1 as (A1+Lmove1,B1). S42. The visual inspection and positioning module captures the positioning coordinates (C1, D1) of product 1 to obtain the actual position information of product 1 after marking. S43. The visual inspection and positioning module captures the positioning coordinates (A2, B2) of product 2 and records the capture time as T2. The main control and data processing system calculates the compensation distance Lmove2 = (Tmarking2 - T2) × V, and determines the initial marking coordinates of product 2 by the laser marking machine as (A2 + Lmove2, B2), where Tmarking2 is the marking time of product 2. S44. Calculate X1 = Lmove2 × [(D1-B1) / (C1-A1)] using an approximate triangular model, where X1 is the estimated deviation in the Y-axis direction; S45. Set the correction amount K, and finally calculate the Y-axis coordinate compensation value = X1 + K; S46. Correct the actual marking coordinates of product 2 to (A2+Lmove2,B2+Y compensation).

2. The flying laser marking system as described in claim 1, characterized in that: The upstream of the marking visual positioning module is also provided with an anti-stacking mechanism, which includes an inclined soft brush, which is positioned above the product support belt and corresponds to the product placement position; a product storage box is provided at the bottom of the end of the synchronous belt in the conveying direction, and an anti-jamming mechanism is also provided between the end of the synchronous belt and the product storage box.

3. The flying laser marking system as described in claim 1, characterized in that: The product support belt has a longitudinal groove array structure, and the defective product rejection mechanism adopts an air blowing module. The air blowing module is installed on one side of the synchronous belt, and a defective product storage box is set on the opposite side of the synchronous belt from the air blowing module, so that the air blowing module blows the defective products into the defective product storage box through jet air.

4. The flying laser marking system as described in claim 1, characterized in that: The product support belt has a single or multiple transverse groove structure; the defective product rejection mechanism includes a 180-degree rotating arm with suction cups at both ends, and a defective product storage box is provided on one side of the conveying mechanism within the rotation range of the rotating arm.

5. The flying laser marking system as described in claim 1, characterized in that: The feeding mechanism includes a vibratory feeder, a linear vibratory guide rail, and a rotating arm. The linear vibratory guide rail is located at the discharge port of the vibratory feeder and has a groove corresponding to the length, width, or diameter of the product. A rotating cylinder is connected to the middle of the rotating arm, and a suction cup is provided at each of the left and right ends of the rotating arm. One suction cup is located above the guide groove of the linear vibratory guide rail, and the other suction cup corresponds to the conveying mechanism.

6. A method for flight laser marking based on the flight laser marking system according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Feeding control: The feeding mechanism transports the product to the moving product support belt. The main control and data processing system controls the feeding time of the feeding mechanism based on the detection signal of the light reflection sensor. S2, Visual positioning before marking: The visual positioning module of marking captures the product in motion and obtains the product positioning coordinates and rotation angle information. The encoder collects the synchronous belt position information. The main control and data processing system integrates the above information to calculate the marking trigger time and marking coordinates. S3, Laser Marking: When the marking trigger time is reached, the main control and data processing system controls the laser marking machine to adjust the galvanometer deflection angle and perform laser marking on the product; S4, Y-axis coordinate calibration and compensation: Calculate the Y-axis compensation value based on the detection data of the vision inspection and positioning module, and correct the marking coordinates of subsequent products; S5. Visual quality inspection after marking: The visual inspection and positioning module photographs the marked product and judges the marking quality, and performs coordinate positioning for defective products. S6. Defective Product Rejection: The main control and data processing system calculates and controls the defective product rejection mechanism to reject defective products; S7. Product unloading: Products that have passed visual inspection and positioning module inspection are unloaded through the unloading mechanism.

7. The method for flying laser marking as described in claim 6, characterized in that: In step S1, the feeding mechanism has a rotating arm, a rotating cylinder is connected to the middle of the rotating arm, and a suction cup is provided at each of the left and right ends of the rotating arm. The conveying mechanism has a synchronous belt with multiple product support belts arranged longitudinally at equal intervals. The conveying direction of the synchronous belt is transverse, and a groove is formed between adjacent product support belts. Each groove corresponds to a falling edge and a rising edge. A light reflection sensor is provided on one side of the synchronous belt within the stroke range of the rotating arm. The specific steps of the feeding control are as follows: The light reflection sensor continuously detects the falling edge of the groove. The time to trigger the product placement is Ti+t period, where Ti is the time when the light reflection sensor detects the falling edge, and t period is the time when the synchronous belt moves one groove spacing, i=1, 2, 3...; When the product is in place on the rotating arm, the actual trigger placement time is Tn+t period, where Tn is the time when the light reflection sensor detects the first falling edge after the rotating arm is in place.

8. The method for flying laser marking as described in claim 6, characterized in that: In step S2, the visual positioning before marking specifically includes: S21. When a product passes through the inspection area, the first industrial camera is triggered to take a picture or take a timed picture under the control of the main control and data processing system. The picture taking cycle is matched with the speed of the synchronous belt movement to ensure that each product is photographed at least once. S22. The first vision processing unit processes the image captured by the first industrial camera and calculates the current coordinates (X1, Y1, θ1) of the product, where θ1 is the rotation angle. At the same time, the encoder collects the X-direction coordinate information of the synchronous belt in real time and sends both to the main control and data processing system. S23. The main control and data processing system integrates the product positioning coordinates, the synchronous belt position information, and the effective marking area information of the laser marking machine to determine whether the product center coordinates fall within the marking center area. If the product center coordinates are within the marking center area, the marking trigger time and marking coordinates are calculated. The marking trigger time = T1 + delay time, where T1 is the photo taking time of the marking vision positioning module, and the delay time is calculated based on the synchronous belt speed and the distance from the product to the marking position. S24. Store the calculated marking trigger time and marking coordinates into the marking information queue. The marking information queue is stored in a first-in-first-out manner. When the marking tasks in the queue reach the trigger time, they are popped out of the queue in order and executed.

9. The method for flying laser marking as described in claim 6, characterized in that: The effective marking area of ​​a laser marking machine includes a maximum marking area and a marking center area. The coordinates of the maximum marking area are (0-w / 2, 0-h / 2, w, h), and the coordinates of the marking center area are (0-w / 2+r, 0-h / 2+r, w-2r, h-2r), where w is the width of the marking area, h is the height of the marking area, and r is the maximum radius of the product. The main control and data processing system determines whether the product's center coordinates fall within the marking center area; only products within this area will be marked. When the marking task in the marking information queue reaches the preset marking trigger time, the main control and data processing system sends a marking instruction to the laser marking machine. The galvanometer component of the laser marking machine adjusts the deflection angle in real time according to the received marking coordinates and rotation angle information, so that the laser beam accurately acts on the target marking position of the product. At the same time, the laser marking machine emits a laser to mark the product, completing the marking action.

10. The flying laser marking method as described in claim 6, characterized in that: It also includes data recording steps, where the main control and data processing system records the marking time, marking coordinates, compensation value, quality inspection results, and rejection status information for each product, enabling full-process traceability of product quality.

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