Large barrel appearance printing on-line visual detection system

Abstract

The utility model discloses a vat appearance printing on-line visual inspection system which comprises a product conveying line used for transporting vats, a steering conveying line is arranged at the tail end of the product conveying line, one discharging end of the steering conveying line is connected with a qualified product conveying line, and the other discharging end of the steering conveying line is connected with a defective product conveying line. A detection frame is fixedly connected to the product conveying line frame body, an area array industrial camera and a linear array industrial camera are arranged on the detection frame for cooperative work, a large barrel is conveyed into the detection frame through the product conveying line by arranging the product conveying line, the defective product conveying line, the qualified product conveying line and the steering conveying line, and after detection of the two cameras, the large barrel is conveyed into the detection frame through the steering conveying line. Through the arranged steering conveying line, the detected large barrels are conveyed to the qualified product conveying line or the defective product conveying line, so that the qualified large barrels and the unqualified large barrels are automatically distinguished, manual carrying and sorting of the large barrels are avoided, the detection speed and the detection efficiency are not affected, and the universality, the adaptability and the automation level of equipment are greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of printing inspection on the exterior of large barrels, and in particular to an online visual inspection system for printing on the exterior of large barrels. Background Technology

[0002] Large drums, as common industrial containers, are widely used to store liquids, powders, or other special materials. Because they are often used to store substances with specific chemical properties or hazards, their outer walls usually require spraying or printing warning signs, product information, and other markings. These markings not only serve a warning function but also directly affect the product's compliance and market circulation. Therefore, after printing on the drums, it is crucial to inspect their appearance quality to identify printing defects (such as omissions, misprints, color deviations, etc.) or surface damage (such as scratches, dents, etc.). However, existing inspection equipment still has many shortcomings in terms of efficiency, comprehensiveness, and accuracy. For example, Chinese utility model patent CN219037904U discloses a visual inspection system for the outer side of a cylindrical barrel. When inspecting a cylindrical barrel, the barrel is placed on a disc below a fixed frame. Two cylinders are then activated to move a lifting plate, positioning the barrel between the two discs. The driving component drives the discs, causing the barrel to rotate. Simultaneously, a line scan camera and a line scan light source capture and record images. When the barrel rotates and captures a full rotation of its outer side, a circumferentially unfolded image is generated. The line scan camera transmits the image to an industrial computer for processing. The visual inspection software in the industrial computer performs algorithmic calculations on the image, thereby analyzing and inspecting the product's height, dimensions, and appearance quality.

[0003] First, the line scan camera used in the aforementioned utility model patent only captures images of the side of the barrel and fails to detect the top surface, resulting in incomplete detection. This single-view detection method cannot meet the needs of applications with high printing quality requirements, especially when complex patterns or text are printed on the top surface, significantly increasing the risk of missed detection. As an important information display area, the lack of detection of the top surface may directly affect the product's compliance and safety.

[0004] Secondly, the clamping mechanism in the aforementioned utility model patent uses a cylinder-driven system to push the lifting plate to fix the cylindrical barrel. However, its clamping range is fixed, making it difficult to precisely adjust the clamping force and position, and it cannot adapt to large barrels of different diameters or heights. This design limits the versatility of the equipment and makes it difficult to meet diverse production needs.

[0005] Furthermore, the existing conveyor line design of the large barrel appearance inspection equipment is simplistic. After inspection, qualified and defective products are mixed together on the same production line, requiring manual sorting of qualified and defective products on the same line. This results in low inspection efficiency and makes it difficult to match with high-speed production lines. In addition, manual sorting not only increases labor costs but may also lead to sorting errors, affecting the consistency of product quality.

[0006] In summary, existing large barrel appearance inspection technologies have significant shortcomings in terms of inspection range, equipment adaptability, sorting efficiency, and imaging accuracy. There is an urgent need for a vision inspection system that can comprehensively inspect the printing quality of large barrels, adapt to barrels of different sizes, and achieve efficient and automated sorting. Utility Model Content

[0007] The purpose of this invention is to provide an efficient, accurate, and highly adaptable online visual inspection system for printing on the exterior of large barrels.

[0008] To achieve the above objectives, this utility model adopts the following solution: an online visual inspection system for printing on the exterior of large barrels, comprising:

[0009] Product conveyor line, used to transport large barrels to be tested;

[0010] A diversion conveyor line, located at the end of the product conveyor line, is used to divert the large barrels to different paths;

[0011] The qualified product conveyor line and the defective product conveyor line are respectively connected to different discharge ends of the turning conveyor line;

[0012] The inspection frame is fixedly installed in a frame shape above the product conveyor line;

[0013] An area array industrial camera is mounted on the inspection frame near the starting point of the product conveyor line via a fixing plate.

[0014] Linear industrial cameras are symmetrically arranged on the left and right opposite side walls inside the inspection frame, near the end of the product conveyor line.

[0015] The steering mechanism is symmetrically arranged on the two inner left and right side walls of the inspection frame near the end of the product conveyor line. It is used to clamp and rotate the large barrel so that the line scan industrial camera can scan the side appearance of the large barrel.

[0016] By employing a combination of area-scan and line-scan industrial cameras, the problem of existing technologies only detecting the sides while neglecting the top surface is solved, achieving comprehensive inspection and significantly reducing the missed detection rate. Simultaneously, a deflecting conveyor automatically separates qualified and defective products to different conveyor lines, avoiding the inefficiency and error risks of manual sorting, thus improving sorting efficiency and production line automation. Furthermore, the deflecting mechanism design addresses the issue of existing equipment having a fixed clamping range and being unable to adapt to large barrels of different sizes, enhancing the equipment's versatility.

[0017] As a further embodiment of this invention, the steering mechanism comprises a sliding frame, a locking block, an electric push rod, and a clamping frame. The sliding frame is movably mounted on both the front and rear sides of each line-scan industrial camera, arranged in pairs. The locking block adopts an I-shaped design and is installed within the sliding frame. The electric push rod is horizontally fixed to the locking block, with its telescopic end passing through the locking block and fixedly connected to the back of the clamping frame. The clamping frame has a U-shaped structure, with a vertically mounted and rotatable rubber roller shaft installed inside. The electric push rod causes the clamping frames on the left and right sides, facing each other, to move horizontally in opposite directions, cooperating to clamp the outer wall of the large barrel. This solution, by controlling the horizontal movement of the clamping frame with an electric push rod, solves the problems of inflexible clamping and difficulty in precisely adjusting force and position in the prior art, ensuring a stable and reliable clamping process. Simultaneously, the clamping frame's rubber roller shaft design adapts to barrels of different diameters, avoiding damage to the barrel body and further improving the flexibility and applicability of the equipment.

[0018] In a preferred embodiment of this invention, the sliding frame has a T-shaped structure, with guide rails at the top and bottom of the detection frame, allowing the top and bottom of the sliding frame to insert into the corresponding guide rails, thus enabling horizontal movement of the sliding frame in the front-to-back direction. Simultaneously, the clamping block is driven to rise and fall via an electric telescopic rod installed within the sliding frame, adjusting the height of the clamping frame. This allows the large barrel clamped between the rubber rollers to be lifted away from the product conveyor line below, and the barrel body to rotate with the help of the rotation of the rubber rollers. The electric telescopic rod driving the sliding frame to rise and fall solves the problem of non-adjustable clamping height in existing technologies, enabling it to accommodate barrels of different heights. Furthermore, the design of lifting the barrel away from the conveyor line after clamping avoids interference from conveyor line vibrations during the detection process, improving detection accuracy and stability.

[0019] As a further embodiment of this invention, bidirectional lead screws are respectively installed at the top and bottom edges where the line array industrial cameras are located on both sides of the inspection frame. One end of each bidirectional lead screw extends into the adjacent guide rail and is threadedly connected to the surface of the sliding frame arranged in front and behind; the other end extends outside the inspection frame and is driven by a servo motor to precisely control the horizontal displacement of the sliding frame, ensuring accurate clamping position. Simultaneously, the bidirectional lead screws can dynamically adjust the clamping distance according to the diameter of the large barrel, further enhancing the flexibility and adaptability of the equipment.

[0020] In a preferred embodiment of this invention, the sides, top, and bottom of the clamping frame extend outwards and are fixed to the sliding frame via an insertion method, thereby enhancing clamping stability. Furthermore, at least one clamping frame on the same side is equipped with a rotary motor connected to a rubber roller shaft, allowing the rubber roller shaft to rotate. This rotation, through friction, drives the large barrel to rotate smoothly, preventing it from shifting during rotation. Simultaneously, the rotary motor drives the rubber roller shaft to rotate, ensuring smooth rotation of the large barrel, improving the image quality acquired by the line scan camera, and further enhancing detection accuracy.

[0021] In a preferred embodiment of this invention, the line scan industrial camera is equipped with a line scanning light source to assist in capturing images of the side profile of the large barrel. The images captured by the line scan and area scan industrial cameras are synchronously transmitted via an Ethernet interface to an industrial computer located on one side of the product conveyor line. The industrial computer uses built-in vision inspection software to perform algorithmic analysis on the top and side images of the large barrel. The uniform illumination provided by the line scanning light source solves the problem of insufficient imaging accuracy in existing technologies, significantly improving image clarity. Simultaneously, synchronous image transmission ensures efficient stitching and analysis of the top and side images, accelerating image processing speed and improving detection efficiency and accuracy.

[0022] In a preferred embodiment of this invention, the area array industrial camera and the line array industrial camera are symmetrically installed on both sides of the end of the inspection frame in the form of multiple units, and work together to complete the inspection tasks of the top and sides of the large barrel, respectively. By working collaboratively with multiple camera units, the limitation of single-view inspection in the prior art is solved, ensuring inspection without blind spots. At the same time, the multiple cameras cover a wider area, improving the detection capability of complex patterns and text, and significantly reducing the missed detection rate.

[0023] In a preferred embodiment of this invention, the redirecting conveyor line is a ball-bearing conveyor belt, while the qualified product conveyor line and the defective product conveyor line are roller-type conveyor belts. Images captured by the area scan industrial camera and the line scan industrial camera are synchronously transmitted to an industrial computer via timestamps for processing. The industrial computer then controls the redirecting conveyor line to deliver the inspected barrels to the qualified product conveyor line or the defective product conveyor line, respectively. This solution achieves redirection and diversion through ball-bearing conveyor belts, solving the problem of low sorting efficiency in existing technologies and meeting the demands of high-speed production lines. Simultaneously, automated sorting reduces human intervention, ensures sorting accuracy, and improves product quality consistency.

[0024] In a preferred embodiment of this invention, the surface of the rubber roller shaft is provided with anti-slip textures, and its rotation speed is 10-30 r / min, matching the frame rate of the linear scan industrial camera to ensure that the images of the outer wall of the large barrel are seamlessly stitched together. The anti-slip textures enhance friction, solving the problem of rotational slippage and ensuring smooth rotation of the large barrel. Simultaneously, the rotation speed matching the frame rate of the linear scan camera ensures seamless image stitching, generating a complete circumferential unfolded image, further improving detection accuracy.

[0025] In a preferred embodiment of this invention, the height adjustment range of the clamping frame via the electric telescopic rod is 50-150mm, thus adapting to large barrels with heights of 500-1500mm. This expanded height adjustment range meets the testing needs of barrels of different heights, enhancing the versatility of the equipment. Simultaneously, precise control of the height adjustment range further improves testing accuracy, avoiding testing errors caused by height mismatch.

[0026] In summary, the advantages of this invention compared to existing technologies are as follows: This invention achieves comprehensive inspection of the top and sides of large barrels through the collaborative work of area-scan and line-scan industrial cameras, significantly reducing the missed inspection rate and solving the problem of existing technologies only inspecting the sides while neglecting the top. Simultaneously, the multi-unit camera design covers a wider area, ensuring no blind spots and improving the ability to identify complex patterns and minute defects. Furthermore, the automatic diversion of qualified and defective products to different conveyor lines via a steering conveyor avoids the inefficiency and error risks of manual sorting, improving sorting efficiency and production line automation. The ball-bearing steering conveyor belt design enables steering and diversion, matching the needs of high-speed production lines and further optimizing the sorting process. Finally, through the design of the steering mechanism, an electric push rod controls the horizontal movement of the clamping frame, and an electric telescopic rod achieves height adjustment, solving the problem of fixed clamping range and inability to adapt to different sized barrels in existing equipment, enhancing the equipment's versatility and flexibility. The introduction of a bidirectional lead screw precisely controls the horizontal displacement of the sliding frame, ensuring accurate clamping position and dynamically adapting to barrels of different diameters, further enhancing clamping stability. Furthermore, uniform illumination provided by a line-scan light source significantly improves image quality. Combined with the anti-slip texture of the rubber roller shaft and its speed-matching design, this ensures smooth barrel rotation and generates a seamlessly stitched circumferential unfolded image, further improving detection accuracy. Finally, the received images are processed by an industrial computer through timestamp synchronization and algorithm analysis, accelerating image processing speed and improving detection efficiency and accuracy. The entire system design not only significantly improves detection efficiency and reliability but also greatly enhances the equipment's versatility, adaptability, and automation level, providing a more comprehensive and efficient solution for the field of barrel appearance printing inspection. Attached Figure Description

[0027] Figure 1This is a three-dimensional structural diagram of the present invention.

[0028] Figure 2 This is a schematic diagram of the structure of the detection frame in this utility model.

[0029] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0030] Figure 4 for Figure 2 Enlarged view of point B in the middle.

[0031] Explanation of reference numerals in the attached diagram: 1. Defective product conveyor line; 2. Qualified product conveyor line; 3. Diverting conveyor line; 4. Inspection frame; 5. Fixing plate; 6. Area scan industrial camera; 7. Line scan industrial camera; 8. Clamping frame; 9. Rubber roller shaft; 10. Electric push rod; 11. Sliding frame; 12. Electric telescopic rod; 13. Clamping block; 14. Two-way lead screw; 15. Guide rail; 16. Product conveyor line. Detailed Implementation

[0032] The following detailed description provides various embodiments or examples for implementing this utility model. Of course, these are merely embodiments or examples and are not intended to be limiting. Additionally, repeated reference numerals, such as repeated numbers and / or letters, may be used in different embodiments. These repetitions are for the purpose of simple and clear description of the invention and do not represent a specific relationship between the different embodiments and / or structures discussed.

[0033] Furthermore, spatial terms may be used, such as "below," "lower," "from the inside out," "above," "upper," and similar terms. These relational terms are used to facilitate the description of the relationship between some elements or features in the drawings and other elements or features. These spatial relational terms include different orientations of the device in use or operation, as well as the orientations described in the drawings. The device may be rotated 90 degrees or otherwise to different orientations, and the spatially related adjectives used therein can be interpreted in the same way. Therefore, they should not be construed as limiting the present invention. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments: Figures 1 to 4The illustrated online visual inspection system for the appearance printing of large barrels includes a product conveyor line 16 for transporting large barrels. A deflecting conveyor line 3 is located at the end of the product conveyor line 16. One outlet end of the deflecting conveyor line 3 is connected to a qualified product conveyor line 2, and the other outlet end is connected to a defective product conveyor line 1. An inspection frame 4 is fixedly connected to the frame of the product conveyor line 16. A fixing plate 5 is fixedly connected to the inspection frame 4 near the starting point of the product conveyor line 16. An area array industrial camera 6 for inspecting the top surface of the large barrel is fixedly connected to the bottom surface of the fixing plate 5. Two line array industrial cameras 7 and a deflecting mechanism are symmetrically arranged on opposite sidewalls of the inspection frame 4 near the end of the product conveyor line 16. After the printed barrels are inspected by the inspection rack 4 on the product conveyor line 16, they pass through the turning conveyor line 3. Barrels that pass the printing process enter the qualified product conveyor line 2, while barrels that fail the printing process enter the defective product conveyor line 1 for processing after the turning conveyor line 3 adjusts and changes direction. When the barrels pass through the inspection rack 4, they first pass through the area scan industrial camera 6 set on the bottom surface of the fixed plate 5 to acquire an image of the top surface of the barrel. When they pass through the two line scan industrial cameras 7, the barrels are rotated by the turning mechanism, and the line scan industrial cameras 7 can then acquire a complete image of the printed outer wall of the barrel. The product conveyor line 16 uses an 800mm wide roller conveyor belt to transport products to the inspection area at a speed of 0.5–1.5 m / s. The deflecting conveyor line 3 uses a ball bearing conveyor belt to achieve deflection and diversion. The qualified product conveyor line 2 and the defective product conveyor line 1 both use roller conveyor belts. The images captured by the area scan industrial camera 6 and the line scan industrial camera 7 are synchronously transmitted to an industrial computer via timestamps for processing. The industrial computer then controls the deflecting conveyor line 3 to send the inspected barrels to the qualified product conveyor line 2 or the defective product conveyor line 1, respectively. The inspection area is constructed based on a frame-like inspection frame 4 fixed to the product conveyor line 16, with dimensions approximately 2.5m high and 1.2m wide. At the starting point of the inspection rack 4 near the product conveyor line 16, multiple 50-megapixel area scan industrial cameras 6 with a frame rate of 30fps are fixedly installed to capture printed images of the top surface of the large barrel. At the end of the inspection rack 4, two sets of multiple line scan industrial cameras 7 with a resolution of 8192 pixels and a line frequency of 66.6 kHz are arranged symmetrically on the left and right sides, equipped with line scan light sources to assist in capturing images of the side of the large barrel. The images captured by both types of cameras are transmitted synchronously in real time via Ethernet interface after being timestamped to an industrial computer set up on one side of the product conveyor line 16. The vision inspection software pre-installed in the computer uses an image stitching algorithm to synthesize the images continuously captured by the line scan cameras into a complete circumferential unfolded image, and uses a defect detection algorithm based on HSV color space threshold segmentation to accurately identify defects in the printed area.After the acquired images are processed quickly by an industrial computer, the system judges the printing quality based on the analysis results of the detection algorithm. The qualified barrels are automatically sent to the qualified product conveyor line 2 via the turning conveyor line 3, while the unqualified barrels are sent to the defective product conveyor line 3 for further processing.

[0035] In addition, the steering mechanism in this utility model is symmetrically arranged on the two inner left and right symmetrical side walls of the detection frame 4 near the end of the product conveyor line 16. It is used to clamp and rotate the large barrel, so that the line scan industrial camera 7 can complete the scanning of the side appearance of the large barrel. Specifically: the steering mechanism consists of a sliding frame 11, a locking block 13, an electric push rod 10 and a clamping frame 8. The sliding frame 11 is movably arranged on the front and rear sides of each line scan industrial camera 7 and is arranged in pairs. The locking block 13 adopts an I-shaped design and is installed in the sliding frame 11. The electric push rod 10 is horizontally fixed on the locking block 13, and its telescopic end passes through the locking block 13 and is fixedly connected to the back of the clamping frame 8. The clamping frame 8 has a U-shaped structure and a vertically arranged and rotatable rubber roller shaft 9 is installed inside. The electric push rod 10 causes the clamping frames 8 facing each other on the left and right sides to move horizontally in opposite directions, cooperating with each other to clamp the outer wall of the large barrel. Next, at least one clamping frame 8 on the same side is equipped with a rotary motor connected to the rubber roller shaft 9. Driven by the rotary motor, the rubber roller shaft 9 is rotated. The surface of the rubber roller shaft 9 is provided with anti-slip texture. Its rotation speed is 10-30 r / min, which matches the acquisition frame rate (1000-2000 frames / second) of the line scan industrial camera 7. The friction force drives the large barrel to rotate smoothly, ensuring that the images of the outer wall of the large barrel do not overlap and are stitched together, so that the images from all angles on the side can be completely acquired.

[0036] In addition, such as Figure 2 and Figure 3 As shown, the sliding frame 11 has a T-shaped structure. Guide rails 15 are respectively provided at the top and bottom of the detection frame 4, allowing the top and bottom of the sliding frame 11 to insert into the corresponding guide rails 15, thus enabling horizontal movement of the sliding frame 11 in the front-to-back direction. Simultaneously, the clamping block 13 is driven to rise and fall via an electric telescopic rod 12 installed within the sliding frame 11, adjusting the height of the clamping frame 8. This allows the large barrel clamped between the rubber roller shafts 9 to be lifted away from the product conveyor line 16 below, and the barrel body to rotate with the help of the rotation of the rubber roller shafts 9. The height adjustment range of the clamping frame 8 via the electric telescopic rod 12 is 50-150mm, thus adapting to large barrels with a height of 500-1500mm.

[0037] like Figure 2 and Figure 4As shown, the spacing between the sliding frames 11 on the same side of this invention is adjustable to accommodate large barrels of different diameters and heights. Specifically, bidirectional lead screws 14 are respectively installed at the top and bottom edges where the line array industrial cameras 7 are located on both sides of the inspection frame 4. One end of the bidirectional lead screw 14 extends into the adjacent guide rail 15 and is threadedly connected to the surface of the sliding frames 11 arranged in front and behind; the other end extends to the outside of the inspection frame 4 and is driven by a servo motor installed on the inspection frame 4 to precisely control the horizontal displacement of the sliding frames 11. The pitch of the bidirectional lead screw 14 is 5mm, and the horizontal displacement adjustment range of the sliding frames 11 is 200-800mm to accommodate large barrels with diameters of 300-700mm. Specifically, by using a servo motor to drive the bidirectional lead screw 14 to rotate, the two sliding frames 11 that are threadedly connected to the bidirectional lead screw 14 can be moved closer or further apart, thereby adjusting the position of the sliding frames 11, which in turn adjusts the position of the locking block 13, and thus adjusts the distance between the two rubber roller shafts 9 located on the same side of the detection frame 4, making it easier to fit the outer wall of the barrel with different curvatures.

[0038] The wiring diagrams for the area array industrial camera 6, line array industrial camera 7, motor, electric push rod 10, electric telescopic rod 12, roller conveyor belt, and ball conveyor belt in this utility model are common knowledge in the field. Their working principles are known technologies. The appropriate model is selected according to actual use. Therefore, the control methods and wiring layouts for the area array industrial camera 6, line array industrial camera 7, motor, electric push rod 10, electric telescopic rod 12, roller conveyor belt, and ball conveyor belt will not be explained in detail.

[0039] The foregoing has shown and described the basic principles and main features of this utility model, as well as its advantages. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An online visual inspection system for printing on the exterior of large barrels, characterized in that, include: Product conveyor line (16), used to transport large barrels to be tested; A diversion conveyor line (3) is set at the end of the product conveyor line (16) to divert the barrels to different paths; The qualified product conveyor line (2) and the defective product conveyor line (1) are respectively connected to different discharge ends of the turning conveyor line (3); The inspection frame (4) is fixedly installed above the product conveyor line (16) in a frame shape; An area array industrial camera (6) is mounted on the inspection frame (4) near the starting point of the product conveyor line (16) via a fixing plate (5); Linear industrial cameras (7) are symmetrically arranged on the left and right opposite side walls inside the inspection frame (4) and close to the end of the product conveyor line (16); The steering mechanism is symmetrically arranged on the two inner left and right side walls of the detection frame (4) near the end of the product conveyor line (16), and is used to clamp and rotate the large barrel so that the line scan industrial camera (7) can complete the scanning of the side appearance of the large barrel.

2. The online visual inspection system for printing on the exterior of large barrels according to claim 1, characterized in that, The steering mechanism consists of a sliding frame (11), a locking block (13), an electric push rod (10), and a clamping frame (8). The sliding frame (11) is movably arranged on the front and rear sides of each line array industrial camera (7) and arranged in pairs. The locking block (13) adopts an I-shaped design and is installed inside the sliding frame (11). The electric push rod (10) is horizontally fixed on the locking block (13), and its telescopic end passes through the locking block (13) and is fixedly connected to the back of the clamping frame (8). The clamping frame (8) has a U-shaped structure and a vertically arranged and rotatable rubber roller shaft (9) is installed inside. The electric push rod (10) causes the clamping frames (8) facing each other on the left and right sides to move horizontally in opposite directions and cooperate with each other to clamp the outer wall of the barrel.

3. The online visual inspection system for printing on the exterior of large barrels according to claim 2, characterized in that, The sliding frame (11) has a T-shaped structure. Guide rails (15) are provided at the top and bottom of the detection frame (4) respectively, so that the top and bottom of the sliding frame (11) can be inserted into the corresponding guide rails (15) respectively, so as to realize the horizontal movement of the sliding frame (11) in the front and back directions. At the same time, the clamping block (13) is driven to lift and lower by the electric telescopic rod (12) set in the sliding frame (11) to adjust the height of the clamping frame (8), so that the large barrel clamped between the rubber roller shafts (9) can be lifted away from the product conveying line (16) below, and the barrel body can be rotated by means of the rotation of the rubber roller shafts (9).

4. The online visual inspection system for printing on the exterior of large barrels according to claim 3, characterized in that, Bidirectional lead screws (14) are respectively provided at the top and bottom edges where the line array industrial cameras (7) are located on both sides of the detection frame (4). One end of the bidirectional lead screw (14) extends into the adjacent guide rail (15) and is connected to the surface of the sliding frame (11) arranged in front and behind by threads; the other end extends to the outside of the detection frame (4) and is driven by a servo motor to precisely control the horizontal displacement of the sliding frame (11).

5. The online visual inspection system for printing on the exterior of large barrels according to claim 4, characterized in that, The sides, top and bottom of the clamping frame (8) extend outward and are fixed to the sliding frame (11) by plugging, thereby enhancing the clamping stability. In addition, at least one clamping frame (8) on the same side is provided with a rotary motor connected to the rubber roller shaft (9), so that the rubber roller shaft (9) can rotate and drive the large barrel to rotate smoothly through friction.

6. The online visual inspection system for printing on the exterior of large barrels according to claim 5, characterized in that, The line scan industrial camera (7) is equipped with a line scan light source to assist in capturing images of the side appearance of the large barrel; and the images captured by the line scan industrial camera (7) and the area scan industrial camera (6) are synchronously transmitted to the industrial computer set on one side of the product conveyor line (16) through the Ethernet interface. The industrial computer performs algorithm analysis on the top and side images of the large barrel through built-in vision inspection software.

7. The online visual inspection system for printing on the exterior of large barrels according to claim 6, characterized in that, The area array industrial camera (6) and the line array industrial camera (7) are symmetrically installed on both sides of the end of the inspection frame (4) in multiple units, and work together to complete the inspection tasks of the top and sides of the barrel respectively.

8. The online visual inspection system for printing on the exterior of large barrels according to claim 7, characterized in that, The turning conveyor line (3) is a ball bearing conveyor belt, the qualified product conveyor line (2) and the defective product conveyor line (1) are roller conveyor belts. The images collected by the area array industrial camera (6) and the line array industrial camera (7) are synchronously transmitted to the industrial computer for processing via timestamps. The industrial computer then controls the turning conveyor line (3) to send the inspected barrels to the qualified product conveyor line (2) or the defective product conveyor line (1) respectively.

9. The online visual inspection system for printing on the exterior of large barrels according to claim 8, characterized in that, The surface of the rubber roller shaft (9) is provided with anti-slip texture, and its rotation speed is 10-30 r / min, which matches the acquisition frame rate of the line array industrial camera (7) to ensure that the images of the outer wall of the barrel do not overlap.

10. The online visual inspection system for printing on the exterior of large barrels according to any one of claims 1 to 9, characterized in that, The height adjustment range of the clamping frame (8) via the electric telescopic rod (12) is 50-150mm, thus adapting to large barrels with a height of 500-1500mm.

Images