Multi-model liquefied gas steel cylinder steel seal code identification method and system

Abstract

The invention discloses a steel seal code identification method and system for multi-model liquefied gas steel cylinders, belongs to the technical field of steel cylinder identification, and solves the problems that steel seal codes of different models of liquefied gas steel cylinders are difficult to identify and the working efficiency of manual code reading is low. The rotation control module is used for adjusting the opening orientation of the steel cylinder opening shield, and the laser transmitter and the laser receiver are used for judging whether the steel cylinder rotates in place or not so as to determine that the steel seal code area of the steel cylinder is aligned with the camera; the steel cylinder shield is divided into a plurality of areas according to the distribution condition of steel seal codes of different types of steel cylinders, and steel seal code information of different areas is photographed and identified, so that the identification efficiency of the steel seal information of the liquefied petroleum gas steel cylinder is improved, the labor cost is reduced, and the accuracy and the working efficiency of steel seal code identification are effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of cylinder identification, and relates to a method and system for identifying the steel stamp codes of multi-type liquefied gas cylinders. Background Art

[0002] The steel stamp information of liquefied petroleum gas cylinders is the only lifelong identifier for identifying the identity of the cylinders and is an important basic support for the whole-life cycle supervision of the cylinders. The steel stamp code is a 12-digit digital string imprinted on the cylinder protection cover by means of a hydraulic device and other devices according to the requirements of the "Special Equipment Safety Law of the People's Republic of China". For example, the steel stamp code contains the production date and scrapping date of the cylinder, which belongs to the important information for cylinder inspection. As the country's management of special equipment becomes more and more strict, cylinder manufacturers, inspection manufacturers, etc. need to timely read the steel stamp code information of the cylinders and apply the steel stamp code information to all links in the whole process of cylinder production and inspection, and read and record the steel stamp codes of the cylinders.

[0003] The prior art, such as the invention patent with the application publication number CN109704010A, discloses a device for automatically positioning and visually identifying the numbers of liquefied gas cylinders. Among them, the accumulation wheel conveyor line is horizontally arranged on the base, and liquefied petroleum gas cylinders are placed thereon; the bottle blocking device is located at one end of the accumulation wheel conveyor line; the bottle lifting device can penetrate the accumulation wheel conveyor line; the bottle rotating device is located on both sides of the accumulation wheel conveyor line; the protective cover positioning and photographing device is located above the accumulation wheel conveyor line. According to the above, the stamping numbers on the protective cover of the liquefied petroleum gas cylinder can be automatically positioned. However, since the steel stamp code information contained in the cylinders produced by different manufacturers is not the same, and the specific positions of the steel stamp codes are not the same, the above device cannot effectively identify the steel stamp information of multi-type liquefied petroleum gas cylinders. For the identification of the steel stamp codes of liquefied petroleum gas cylinders, manual code copying is still mainly used at present, which consumes a lot of labor, has low efficiency, and is prone to errors. Therefore, there is an urgent need for an identification method that can support multiple different manufacturer models, automatically identify the steel stamp information, and bind the steel stamp information with an RFID rapid identification device. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to solve the problems that it is difficult to identify the steel stamp codes of multi-type liquefied petroleum gas cylinders and the manual code copying work efficiency is low.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] A method for identifying the steel stamp codes of multi-type liquefied gas cylinders includes the following steps:

[0007] S1. Control the cylinder to move horizontally to a preset position, rotate the cylinder body until the cylinder rotates in place, and adjust the steel stamp code to a position where it can be photographed;

[0008] S2. When the cylinder rotates into place, send a high-level signal to the master control software. The master control software starts the camera to take pictures and the flash light source to take pictures of the cylinder shroud area;

[0009] S3. Based on the captured image, use the trained AI recognition model to perform string recognition on the steel stamp code contained in the cylinder shroud area, and determine whether the recognition result conforms to the preset recognition rule. If it conforms, the production line continues to convey the cylinder. If it does not conform, an error alarm is generated, and manual intervention is required to recycle the cylinder or perform recognition again;

[0010] S4. After the steel stamp code recognition conforms to the recognition rule, the master control software sends an RFID tag reading signal to bind the read steel stamp code and the RFID serial number one by one;

[0011] S5. When the cylinder flows through each production process on the production line, read the RFID information of the cylinder and record the inspection results of the cylinder in the current production process to generate a cylinder inspection report.

[0012] Further, the S1 includes the following steps:

[0013] S11. Use the roller conveyor belt to control the horizontal movement of the cylinder, send the cylinder into the laser irradiation range of the laser rangefinder, measure the distance between the cylinder and the laser rangefinder, and determine whether the cylinder reaches the preset position;

[0014] S12. When the cylinder reaches the preset position, the laser rangefinder sends a control signal to the blocking module. The blocking module prevents subsequent cylinders from entering the preset position and sends a start signal to the rotation control module. The rotation control module drives the cylinder to rotate;

[0015] S13. Use the laser emitter to emit laser light through the preset position to the laser receiver. If the laser receiver receives the laser signal, it is determined that the cylinder rotates into place and the rotation control module stops. If the laser receiver cannot receive the laser signal, continue to control the cylinder to rotate until the laser receiver receives the laser, and the rotation control module stops the cylinder from rotating into place.

[0016] Further, the blocking module is a robotic arm, and the rotation control module includes a pressure arm and a rubber roller provided on the pressure arm.

[0017] Further, the cylinder shroud area in S2 includes the area beside the first opening, the area beside the second opening, the first connection area, the second connection area, and the central area.

[0018] Further, the string in S3 is specifically:

[0019] The character strings existing in the first opening side area include a string of numbers arranged vertically from top to bottom; the character strings existing in the first connection area include at least one of a string of numbers arranged horizontally from left to right, a two-dimensional punched code and a punched character string, and a common two-dimensional code; the character strings existing in the central area include at least one of the cylinder factory code, the cylinder manufacturing unit code, the production date and the scrapping date, the manufacturer, and the cylinder specification; the character strings existing in the second connection area include at least one of a string of numbers arranged horizontally from left to right and a common two-dimensional code; the character strings existing in the second opening side area include a string of numbers arranged vertically from top to bottom.

[0020] Further, the AI recognition model in S3 is a deep learning model based on OpenCV-CNNs. The specific process of using the trained AI recognition model to recognize the character strings of the steel seal code included in the cylinder guard area is as follows:

[0021] S31. Preprocess the captured image, and the preprocessing includes but is not limited to grayscale conversion, binarization, denoising, and contrast adjustment;

[0022] S32. Correct the tilted or deformed captured image, and the correction is perspective transformation or affine transformation;

[0023] S33. Detect the contour of the captured image to find the area containing the steel seal code in the captured image;

[0024] S34. Train the deep learning model and adopt data augmentation technology to improve the model's recognition ability for the steel seal code;

[0025] S35. Select a loss function and an optimizer, adjust the hyperparameters through cross-validation, and fine-tune the deep learning model;

[0026] S36. Input the processed captured image into the deep learning model to recognize the steel seal code.

[0027] Further, the recognition rules in S3 are specifically as follows:

[0028] If the production date of the cylinder is before 2021, the steel seal code includes 2-digit manufacturer codes arranged in sequence, 1 space, and 5-digit production serial numbers;

[0029] If the production date of the cylinder is after 2021, the steel seal code includes 3-digit digital codes of the cylinder manufacturing unit, 2-digit digital codes of the cylinder manufacturing year, and 7-digit digital serial numbers of the cylinders manufactured by the manufacturing unit in the manufacturing year.

[0030] Further, the production process described in S5 includes appearance inspection of wall thickness, painting and lettering, hydrostatic test, installation of a valve inspection ring, airtight test, and report generation. The inspection results include the start and end times of the process and the process inspection data.

[0031] The present invention also provides a steel stamp code recognition system for multi-type liquefied gas cylinders, including a gas cylinder position control module, a camera photographing control module, a picture storage and recognition module, a label and steel stamp code binding module, and a recognition module for each point on the gas cylinder assembly line;

[0032] The gas cylinder position control module is used to control the horizontal movement of the gas cylinder to a preset position, rotate the gas cylinder body until the gas cylinder rotates in place, and adjust the steel stamp code to a position where it can be photographed;

[0033] The camera photographing control module is used to, when the gas cylinder rotates in place, the gas cylinder position control module sends a high-level signal to the total control software. The total control software starts the camera to take a picture and the flash light source, takes a picture of the gas cylinder guard area. After the photographing is completed, the flash light source is turned off and a signal is sent to the picture storage and recognition module;

[0034] The picture storage and recognition module is used to, based on the photographed image, use the trained AI recognition model to perform string recognition on the steel stamp code included in the gas cylinder guard area, and determine whether the recognition result conforms to the preset recognition rule. If it conforms, the production line continues to convey the gas cylinder. If it does not conform, an error alarm is generated, and manual intervention is required to recycle the gas cylinder or perform recognition again;

[0035] The label and steel stamp code binding module is used to, after the steel stamp code recognition conforms to the recognition rule, the total control software sends an RFID tag reading signal to bind the read steel stamp code and the RFID serial number one by one;

[0036] The recognition module for each point on the gas cylinder assembly line is used to read the RFID information of the gas cylinder when the gas cylinder flows through each production process on the production line, record the inspection results of the gas cylinder in the current production process, and generate a gas cylinder inspection report.

[0037] Further, the gas cylinder position control module includes:

[0038] Use a roller conveyor belt to control the horizontal movement of the gas cylinder, send the gas cylinder into the laser irradiation range of the laser rangefinder, measure the distance between the gas cylinder and the laser rangefinder, and determine whether the gas cylinder reaches the preset position;

[0039] When the gas cylinder reaches the preset position, the laser rangefinder sends a control signal to the blocking module. The blocking module prevents subsequent gas cylinders from entering the preset position and sends a start signal to the rotation control module. The rotation control module drives the gas cylinder to rotate;

[0040] The laser emitter emits laser light through a preset position towards the laser receiver. If the laser receiver receives the laser signal, it is determined that the cylinder has rotated into place, and the rotation control module stops. If the laser receiver cannot receive the laser signal, the cylinder is continuously controlled to rotate until the laser receiver receives the laser, and then the rotation control module stops the cylinder from rotating into place.

[0041] The advantages of the present invention are as follows:

[0042] The present invention uses a rotation control module to adjust the opening orientation of the cylinder mouth guard, and uses a laser emitter and a laser receiver to determine whether the cylinder has rotated into place, so as to determine that the stamped code area of the cylinder is aligned with the camera. According to the distribution of the stamped codes of cylinders of different models, multiple areas are divided on the cylinder guard, and the stamped code information of different areas is photographed and identified, which improves the identification efficiency of the stamped information of liquefied petroleum gas cylinders, reduces labor costs, and effectively improves the accuracy and working efficiency of stamped code identification. Brief Description of the Drawings

[0043] Figure 1 is a flowchart of a method for identifying stamped codes of multi-model liquefied gas cylinders according to Embodiment 1 of the present invention;

[0044] Figure 2 is a schematic diagram of the rotation control module according to Embodiment 1 of the present invention;

[0045] Figure 3 is a schematic diagram for determining that the cylinder has rotated into place according to Embodiment 1 of the present invention;

[0046] Figures 4(a) to 4(b) is a schematic diagram of the distribution of the cylinder guard areas according to Embodiment 1 of the present invention;

[0047] Figure 5 is a schematic diagram of the distribution of stamped codes of multi-model liquefied gas cylinders according to Embodiment 1 of the present invention. Detailed Embodiments

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0049] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings of the specification and specific embodiments:

[0050] Embodiment 1

[0051] As Figure 1As shown, specifically, a method for identifying the steel stamp code of multi - model liquefied gas cylinders is disclosed, including the following steps:

[0052] S1. Control the horizontal movement of the cylinder to a preset position, rotate the cylinder body until the cylinder rotates in place, and adjust the steel stamp code to a position where it can be photographed;

[0053] Since the mouth of a civil liquefied gas cylinder is not completely symmetrical, the cylinder mouth guard includes an open side and a non - open side, and the cylinders face different directions during transportation on the production line. Therefore, it is necessary to accurately control the opening direction of the cylinder mouth guard to ensure that the steel stamp code area of the cylinder is aligned with the camera. In this embodiment, S1 specifically includes:

[0054] S11. Use a roller conveyor belt to control the horizontal movement of the cylinder, send the cylinder into the laser irradiation range of the laser rangefinder, measure the distance between the cylinder and the laser rangefinder, and determine whether the cylinder reaches the preset position;

[0055] S12. When the cylinder reaches the preset position, the laser rangefinder sends a control signal to the blocking module. The blocking module prevents subsequent cylinders from entering the preset position and sends a start signal to the rotation control module. The rotation control module drives the cylinder to rotate;

[0056] In this embodiment, the blocking module is a robotic arm. The laser rangefinder controls the robotic arm to extend through sending an electrical signal to prevent cylinders other than the target cylinder on the roller conveyor belt from entering the laser irradiation range of the laser rangefinder, and at the same time sends an electrical signal to the rotation control module.

[0057] As Figure 2 shown, the rotation control module includes a pressure arm 12 and a rubber roller 11 arranged on the pressure arm 12. The two pressure arms 12 apply pressure from the left and right sides of the cylinder, pushing the rubber roller 11 to contact the cylinder body. The contact between the rubber roller 11 and the cylinder body generates pressure. When the rotation control module receives the start signal, the rubber roller 11 rolls to drive the cylinder to rotate.

[0058] S13. Use a laser emitter to emit laser through the preset position to a laser receiver. If the laser receiver receives the laser signal, it is determined that the cylinder rotates in place and the rotation control module stops; if the laser receiver cannot receive the laser signal, continue to control the cylinder to rotate until the laser receiver receives the laser, and the rotation control module stops the cylinder from rotating in place;

[0059] As Figure 3As shown, in this embodiment, taking advantage of the semi-circular shape of the cylinder mouth guard, a laser emitter and a laser receiver are respectively installed on the left and right sides of the cylinder. The laser emitted by the laser emitter passes through a preset position and forms a straight line with the laser receiver, so that the laser emitted by the laser emitter is exactly at the edge of the guard. The laser emitter continuously emits laser, which is blocked by the cylinder mouth guard when passing through the preset position. When the laser receiver receives the laser signal, the laser emitted by the laser emitter passes through the edge of the cylinder mouth guard and is received by the laser receiver, determining that the cylinder has rotated in place; if the laser receiver cannot receive the laser signal, the cylinder rotation is continuously controlled until the laser receiver receives the laser. At this time, the rubber roller 11 stops rolling, the rotation control module stops, and the cylinder has rotated in place.

[0060] Furthermore, considering that the cylinder mouth guard includes an open side and a non-open side, in this embodiment, two beams of laser can also be used for opposite shooting. When irradiating areas outside the open side of the cylinder guard, the two pairs of lasers cannot recognize each other, and it is considered that the current position of the cylinder cannot display the steel stamp code. The rotation control module continuously rotates the cylinder position until the laser irradiates the open side of the upper seal of the cylinder.

[0061] S2. When the cylinder rotates in place, send a high-level signal to the master control software. The master control software starts the camera to take pictures and the flash light source, takes pictures of the cylinder guard area, and after the shooting is completed, turns off the flash light source;

[0062] The cylinder guard area includes the first side area beside the opening, the second side area beside the opening, the first connection area, the second connection area, and the central area. The five cameras respectively take pictures of each area.

[0063] In this embodiment, although different models of liquefied gas cylinders produced by different manufacturers print the steel stamp code on the cylinder guard, the specific area printed on the cylinder guard is different, the specific positions of the steel stamp code are all different, and the coding rules and coding information of the steel stamp code are also different. As Figures 4(a) - 4(b) shown, in this embodiment, the cylinder guard area is divided into five areas. Each area can ensure that all manufacturers that may stamp the steel stamp code in this area are covered, and at the same time, the corresponding 5 cameras are used to take pictures and identify the 5 areas respectively; specifically, the first side area beside the opening and the second side area beside the opening are respectively the left and right side areas of the open side of the cylinder guard (such as area 1 and area 5 in Figure 4), the first connection area and the second connection area are respectively the connection areas between the left and right sides of the cylinder guard and the cylinder body (such as area 2 and area 4 in Figure 4), and the area far from the open side of the cylinder guard is used as the central area. The top of the cylinder guard is a handle, which is prone to wear, and it is generally considered that the handle area will not print the identification code.

[0064] In this embodiment, by taking pictures and summarizing the steel stamp codes in different areas of the cylinder shroud, it is possible to systematically judge the position of the steel stamp code and identify the steel stamp code information, improving the accuracy and working efficiency of steel stamp code recognition.

[0065] S3. Based on the captured image, use the trained AI recognition model to perform string recognition on the steel stamp codes included in the cylinder shroud area, and judge whether the recognition result conforms to the preset recognition rules. If it conforms, the production line continues to convey the cylinder; if not, an error alarm is generated, and manual intervention is required to recycle the cylinder or perform recognition again.

[0066] According to the photos of the five areas of the current cylinder obtained in step S2, use the trained AI recognition model to recognize the strings in the photos. Based on the preset recognition rules and comprehensively considering the recognition results of the five areas, key information such as the manufacturer, production date, and scrapping date included in the steel stamp code of the current cylinder can be obtained.

[0067] Furthermore, the AI recognition model is a deep learning model based on OpenCV-CNNs. The specific operation of using the trained AI recognition model to perform string recognition on the steel stamp codes included in the cylinder shroud area is as follows:

[0068] S31. Preprocess the captured image, and the preprocessing includes but is not limited to grayscale conversion, binarization, denoising, and contrast adjustment.

[0069] S32. Correct the tilted or deformed captured image, and the correction is perspective transformation or affine transformation.

[0070] S33. Perform contour detection on the captured image to find the area containing the steel stamp code in the captured image.

[0071] In this embodiment, based on OpenCV (Open Source Computer Vision Library), image preprocessing and image correction operations are sequentially performed on the captured image to facilitate subsequent character recognition; using the contour detection function of OpenCV, find the area that may contain the steel stamp code. This operation can effectively reduce the search space of the deep learning model, and apply edge detection algorithms to enhance the boundary information of the steel stamp code, facilitating more accurate positioning.

[0072] S34. Train the deep learning model and use data augmentation techniques to improve the model's recognition ability for steel stamp codes. The data augmentation includes but is not limited to rotation, scaling, translation, and adding noise. In this embodiment, Gaussian blur is used as an example for illustration. The following logic is used to represent using data augmentation techniques to improve the model's recognition ability for steel stamp codes:

[0073]

[0074] Among them, I(x, y) represents the original captured image, I'(x, y) represents data augmentation, * represents the convolution operation, (x, y) represents the coordinates of the two-dimensional pixel grid of the image, and σ represents the standard deviation of the Gaussian distribution in the xy two-dimensional plane;

[0075] S35. Select a loss function and an optimizer, adjust the hyperparameters through cross-validation, and fine-tune the deep learning model;

[0076] In this embodiment, taking the Adam optimizer as an example for illustration, it includes the following steps:

[0077] S351. Calculate the gradient using the following logic:

[0078]

[0079] Among them, g t represents the gradient of the model parameter θ at the t-th iteration, specifically J(θ t ) represents the loss function, θ t represents the model parameter at the t-th iteration, represents the partial derivative of the loss function J(θ t ) with respect to θ;

[0080] S352. Represent the update of the first-order momentum using the following logic:

[0081] m t = β1m t-1 + (1 - β1)g t

[0082] Among them, m t represents the first-order momentum at the t-th iteration, β1 represents the decay rate of the first-order momentum, and m t-1 represents the first-order momentum at the (t - 1)-th iteration;

[0083] S353. Represent the update of the second-order momentum using the following logic:

[0084] v t = β2v t-1 + (1 - β2)g t 2

[0085] Among them, v t represents the second-order momentum at the t-th iteration, β2 represents the decay rate of the second-order momentum, and v t-1 represents the second-order momentum at the (t - 1)-th iteration;

[0086] S354. Calculate the bias correction using the following logic:

[0087]

[0088] Among them, represents the corrected first-order momentum, represents the t-th power of β1, represents the corrected second-order momentum, represents the t-th power of β2;

[0089] S355. Update the model parameters using the following logic:

[0090]

[0091] Among them, w t+1 represents the model parameters updated after the (t + 1)-th iteration, w t represents the model parameters of the t-th iteration, and η and ∈ are both hyperparameters, representing the learning rate and minimum value respectively;

[0092] S36. Input the processed captured image into the deep learning model to identify the steel seal code;

[0093] In this embodiment, when training the model, data augmentation technology is adopted to improve the model's recognition ability for steel seal codes of different qualities; appropriate loss functions and optimizers are selected, and hyperparameters are adjusted through cross-validation to obtain the best model performance; the pre-trained model is fine-tuned to make it more suitable for the data distribution of this scenario; after completing the preliminary image preprocessing and feature localization, the processed image is input into the CNNs for string recognition in the captured image.

[0094] Specifically, the strings existing in the cylinder shroud area are specifically:

[0095] The strings existing in the area beside the first opening include a string of numbers arranged vertically from top to bottom; the strings existing in the first connection area include at least one of a string of numbers arranged horizontally from left to right, a two-dimensional punched code and a punched string, and a common two-dimensional code; the strings existing in the central area include at least one of the cylinder factory code, the cylinder manufacturing unit code, the production date and the scrapping date, the manufacturer, and the cylinder specification; the strings existing in the second connection area include at least one of a string of numbers arranged horizontally from left to right and a common two-dimensional code; the strings existing in the area beside the second opening include a string of numbers arranged vertically from top to bottom.

[0096] In this embodiment, as Figure 5 shown, the positions of the steel seal codes of different manufacturers and different models on the cylinder shroud are different, and the forms of the steel seal codes and the information contained in the steel seal codes are also different. In this embodiment, the cylinder shroud is divided into 5 areas, and the possible information types of different areas are shown in Table 1 below:

[0097] Table 1 Information Type Table Corresponding to Different Cylinder Guard Regions

[0098]

[0099] Specifically, the recognition rule is as follows:

[0100] If the production date of the cylinder is before 2021, the steel stamp code includes 2 - digit manufacturer code arranged in sequence, 1 space, and 5 - digit production serial number;

[0101] If the production date of the cylinder is after 2021, the steel stamp code includes 3 - digit digital code of the cylinder manufacturing unit arranged in sequence, 2 - digit digital code of the cylinder manufacturing year (represented by the last 2 digits of the manufacturing year), and 7 - digit digital serial number of the cylinders manufactured by the manufacturing unit in the manufacturing year (if the digital serial number is less than 7 digits, fill it with 0 in front), forming a 12 - digit ordered string.

[0102] In this embodiment, the recognition rule conforms to and follows the cylinder factory - out coding rule required by national standards. Based on the above - mentioned recognition logic, the information of the strings existing in the cylinder guard regions of manufacturers A - G is recognized as shown in Table 2 below:

[0103] Table 2 Steel Stamp Code Information Table Corresponding to Different Manufacturer Cylinder Guard Regions

[0104]

[0105] According to the above - mentioned determination rule in this embodiment, the final unique cylinder identification code, as well as key information such as the manufacturer, cylinder manufacturing date, and cylinder scrapping date, can be obtained and stored in the database.

[0106] S4. After the steel stamp code recognition conforms to the recognition rule, the total - control software sends an RFID tag reading signal to bind the recognized steel stamp code and RFID serial number one - to - one;

[0107] In this embodiment, since the RFID tag needs to be bound as soon as the steel stamp code is recognized, the total - control software sends an RFID tag reading signal. After manually receiving the reading signal, the RFID tag to be bound is read through an RFID reader, and the total - control software in the background controls the one - to - one matching of the read RFID tag and the recognized steel stamp code. The RFID tag and the steel stamp code are physically associated manually, and the RFID tag is set on the cylinder.

[0108] S5. When the cylinder flows through each production process on the production line, the RFID information of the cylinder is read, and the detection result of the cylinder in the current production process is recorded to generate a cylinder detection report;

[0109] In this embodiment, the production process includes but is not limited to appearance inspection of wall thickness, painting and lettering, hydrostatic test, installation of valve inspection ring, airtight test, and report generation. The test results include but are not limited to the start and end times of the process and the process test data.

[0110] When the steel cylinder rotates through each link of the production line, it needs to go through multiple production processes to complete the entire steel cylinder inspection process. During each process, the RFID tag needs to be identified, and the start and end times of the process and the process test data are recorded. This embodiment takes the airtight test as an example for illustration. When the steel cylinder is transported to the airtight test station, the RFID reader installed at the station reads the RFID information bound to the steel cylinder and records the timestamp at this time as the start time of the airtight test. The master control software controls the start of the airtight test. After the airtight test is completed, the master control software reads the airtight test results and uses the timestamp at this time as the end time of the airtight test. The test results of each production process are used as the basis for generating the subsequent inspection report. Specifically, the steel cylinder inspection report follows the national standard document "Periodic Inspection and Evaluation of Liquefied Petroleum Gas Cylinders" GB / T8334-2022.

[0111] The present invention also discloses a steel seal code recognition system for multi-type liquefied gas cylinders, including a cylinder position control module, a camera photographing control module, a picture storage and recognition module, a tag and steel seal code binding module, and a recognition module for each point on the cylinder assembly line;

[0112] The cylinder position control module is used to control the horizontal movement of the cylinder to a preset position, rotate the cylinder body until the cylinder rotates in place, and adjust the steel seal code to a position where it can be photographed. Specifically:

[0113] Use a roller conveyor belt to control the horizontal movement of the cylinder, send the cylinder into the laser irradiation range of the laser rangefinder, measure the distance between the cylinder and the laser rangefinder, and judge whether the cylinder reaches the preset position;

[0114] When the cylinder reaches the preset position, the laser rangefinder sends a control signal to the blocking module. The blocking module prevents subsequent cylinders from entering the preset position and sends a start signal to the rotation control module. The rotation control module drives the cylinder to rotate;

[0115] Use a laser emitter to emit laser light through the preset position to a laser receiver. If the laser receiver receives the laser signal, it is judged that the cylinder rotates in place and the rotation control module stops; if the laser receiver cannot receive the laser signal, continue to control the cylinder to rotate until the laser receiver receives the laser, and the rotation control module stops the cylinder from rotating in place.

[0116] The camera photographing control module is used to, when the cylinder rotates into place, the cylinder position control module sends a high-level signal to the master control software, and the master control software starts the camera to take a photo and turn on the flash light source (the light source is lit), and takes a photo of the cylinder shroud area. After the photographing is completed, the flash light source is turned off and a signal is sent to the picture storage and recognition module.

[0117] The picture storage and recognition module is used to, based on the captured image, use the trained AI recognition model to perform string recognition on the steel stamp code included in the cylinder shroud area, and determine whether the recognition result conforms to the preset recognition rule. If it conforms, the production line continues to convey the cylinder. If it does not conform, an error alarm is generated, and manual intervention is required to recycle the cylinder or perform recognition again.

[0118] The label and steel stamp code binding module is used to, after the steel stamp code recognition conforms to the recognition rule, the master control software sends an RFID tag reading signal to bind the read steel stamp code and the RFID serial number one by one.

[0119] The cylinder assembly line point position recognition module is used to, when the cylinder flows through each production process on the production line, read the RFID information of the cylinder and record the detection result of the cylinder in the current production process, and generate a cylinder detection report.

[0120] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for identifying steel stamp codes of multiple types of liquefied gas cylinders, characterized in that: The following steps are involved: S1. Control the cylinder to move horizontally to a preset position, rotate the cylinder body until it is in place, and adjust the steel stamp code to a position where it can be photographed; S2, when the cylinder is rotated into place, sends a high level signal to the master control software, and the master control software starts the camera and the flash light source to shoot the cylinder shield area; S3. Based on the captured image, the trained AI recognition model is used to perform string recognition on the steel stamp code contained in the cylinder shield area, and it is determined whether the recognition result meets the preset recognition rules. If it meets the rules, the production line continues to convey the cylinder. If it does not meet the rules, an error alarm is generated, and manual intervention is performed to recycle the cylinder or re-recognize it. S4. After the steel stamp code recognition meets the recognition rules, the master control software sends an RFID tag reading signal, binding the read steel stamp code and RFID serial number one by one; S5. When the cylinder is circulating in each production process of the production line, the RFID information of the cylinder is read and the inspection results of the cylinder in the current production process are recorded to generate a cylinder inspection report.

2. A method for identifying steel stamp codes of multiple types of liquefied gas cylinders according to claim 1, characterized in that: The S1 comprises the following steps: S11, using a roller conveyor to control the horizontal movement of the steel cylinder, sending the steel cylinder into the laser irradiation range of the laser rangefinder, measuring the distance between the steel cylinder and the laser rangefinder, and determining whether the steel cylinder has reached the preset position; S12, when the steel cylinder reaches the preset position, the laser rangefinder sends a control signal to the blocking module, the blocking module prevents the subsequent steel cylinders from entering the preset position, and sends a start signal to the rotation control module, the rotation control module drives the steel cylinder to rotate; S13, using the laser transmitter to transmit laser to the laser receiver through the preset position, if the laser receiver receives the laser signal, it is determined that the cylinder has been rotated into place, and the rotation control module stops; if the laser receiver cannot receive the laser signal, the rotation of the cylinder continues to be controlled until the laser receiver receives the laser, and the rotation control module stops the cylinder from rotating into place.

3. A method for identifying steel stamp codes of multiple types of liquefied gas cylinders according to claim 2, characterized in that: The blocking module is a mechanical arm, and the rotation control module includes a pressure arm and a rubber roller arranged on the pressure arm.

4. A method for identifying steel stamp codes of multiple types of liquefied gas cylinders according to claim 1, characterized in that: The cylinder shield area described in S2 includes a first opening side area, a second opening side area, a first connecting area, a second connecting area and a central area.

5. A method for identifying steel stamp codes of multiple types of liquefied gas cylinders according to claim 4, characterized in that: The string in S3 is: The character string existing in the first opening side area includes a number string arranged from top to bottom in the vertical direction; the character string existing in the first connection area includes a number string arranged from left to right in the horizontal direction, a two-dimensional punched code and a punched character string, and at least one of an ordinary two-dimensional code; the character string existing in the central area includes at least one of a cylinder factory code, a cylinder manufacturing unit code, a production date and a scrapping date, a manufacturer, and a cylinder specification; the character string existing in the second connection area includes a number string arranged from left to right in the horizontal direction and at least one of an ordinary two-dimensional code; the character string existing in the second opening side area includes a number string arranged from top to bottom in the vertical direction.

6. A method for identifying steel stamp codes of multiple types of liquefied gas cylinders according to claim 1, characterized in that: The AI ​​recognition model in S3 is a deep learning model based on OpenCV-CNNs. The trained AI recognition model is used to perform character string recognition on the steel stamp code contained in the cylinder shield area as follows: S31, preprocessing the captured image, including but not limited to grayscale, binarization, denoising, and contrast adjustment; S32, correcting the tilted or deformed captured image, wherein the correction is perspective transformation or affine transformation; S33, performing contour detection on the captured image to find an area in the captured image that contains a steel stamp code; S34, train the deep learning model and use data enhancement technology to improve the model's recognition ability of steel stamp codes; S35. Select loss function and optimizer, adjust hyperparameters through cross-validation, and fine-tune deep learning models; S36. Input the processed captured image into the deep learning model to recognize the steel stamp code.

7. A method for identifying steel stamp codes of multiple types of liquefied gas cylinders according to claim 1, characterized in that: The identification rules described in S3 are specifically: If the cylinder was manufactured before 2021, the stamp code includes a 2-digit manufacturer code, a space, and a 5-digit production serial number in sequence; If the production date of the cylinder is after 2021, the steel stamp code includes a 3-digit digital code of the cylinder manufacturing unit, a 2-digit digital code of the cylinder manufacturing year, and a 7-digit digital serial number of the manufacturing unit in the manufacturing year.

8. A method for identifying steel stamp codes of multiple types of liquefied gas cylinders according to claim 1, characterized in that: The production process described in S5 includes appearance inspection of wall thickness, painting and lettering, water pressure test, installation of valve inspection ring, air tightness test and report generation, and the test results include the start and end time of the process and the process inspection data.

9. A multi-model liquefied gas cylinder steel stamp code recognition system, characterized in that: It includes a gas cylinder position control module, a camera control module, an image storage and recognition module, a label and steel stamp code binding module, and a gas cylinder assembly line point recognition module; The steel cylinder position control module is used to control the horizontal movement of the steel cylinder to a preset position, rotate the steel cylinder body until the steel cylinder is rotated into place, and adjust the steel stamp code to a position where it can be photographed; The camera photo control module is used for sending a high-level signal to the master control software when the steel cylinder is rotated into place, and the master control software starts the camera to take pictures and the flash light source to take pictures of the steel cylinder shield area. After the shooting is completed, the flash light source is turned off and a signal is sent to the picture storage and recognition module; The image storage and recognition module is used to perform character string recognition on the steel stamp code contained in the steel cylinder shield area based on the captured image using the trained AI recognition model, and determine whether the recognition result meets the preset recognition rules. If it meets the rules, the production line continues to convey the steel cylinder. If it does not meet the rules, an error alarm is generated, and manual intervention is performed to recover the steel cylinder or re-recognize it. The tag and steel stamp code binding module is used to wait for the steel stamp code to be identified in accordance with the identification rules, and the master control software sends an RFID tag reading signal to bind the read steel stamp code and RFID serial number one by one; The steel cylinder assembly line point identification module is used to read the RFID information of the steel cylinder and record the inspection results of the steel cylinder in the current production process when the steel cylinder circulates in the various production processes of the production line, and generate a steel cylinder inspection report.

10. A multi-model liquefied gas cylinder steel stamp code recognition system according to claim 9, characterized in that: The cylinder position control module comprises: The roller conveyor is used to control the horizontal movement of the cylinder, and the cylinder is sent into the laser irradiation range of the laser rangefinder, and the distance between the cylinder and the laser rangefinder is measured to determine whether the cylinder has reached the preset position; When the cylinder reaches the preset position, the laser rangefinder sends a control signal to the blocking module, which prevents the subsequent cylinders from entering the preset position and sends a start signal to the rotation control module, which drives the cylinder to rotate; The laser transmitter is used to transmit laser to the laser receiver through the preset position. If the laser receiver receives the laser signal, it is determined that the cylinder has been rotated into place, and the rotation control module stops; if the laser receiver cannot receive the laser signal, the cylinder continues to be controlled to rotate until the laser receiver receives the laser, and the rotation control module stops the cylinder from rotating into place.

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