A multi-jet round bottle printer control method and system

Abstract

The application discloses a kind of control method and system of multi-jet round bottle printer, method includes following steps: S1, import the picture to be printed into system;S2, the shape of bottle and the position of bottle are scanned out by height measuring module algorithm;S3, according to the picture of step S1, the ink drop position on bottle is calculated by algorithm;S4, the ink drop position calculated to step S2 is converted into printing data transmission to round bottle printer;S5, bottle position is confirmed again, and printing is started after no error;The application solves the deficiency of the present round bottle printer in bottle shape detection link, the shape of bottle is accurately calculated by height measuring module, and the ink drop position on bottle is calculated by software, to achieve the purpose of accurate printing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of printers, and in particular to a control method and system of a multi-nozzle round bottle printer. BACKGROUND

[0002] In today's packaging and printing industry, with the continuous improvement of market requirements for product individualization, diversification and environmental protection, round bottle printers, as an innovative printing solution, are gradually emerging. It has many obvious advantages, for example, in terms of printing efficiency, compared with traditional printing and dyeing methods, it does not need complicated plate making process, can directly carry out digital printing operation, greatly shortens the time interval from design to finished product, and can quickly respond to market demand; in terms of sample cost, it avoids high initial investment such as plate making in traditional process, making small batch production more economical and practical; the printing effect is also outstanding, with advanced nozzle technology and precise ink jet control mechanism, it can realize high resolution, colorful and fine pattern printing effect, meeting the strict requirements of high-end products for appearance quality; and from the perspective of environmental protection, it mainly uses environmentally friendly ink, produces less pollutants in the printing process, conforms to the concept of green development, and because of these advantages, round bottle printers, which initially mainly serve sample making and small batch production, with the continuous improvement and maturity of their own process equipment, have now developed into mature technology that can be applied to large-scale production, and have been widely used in the market, gradually replacing the traditional printing and dyeing industry with high energy consumption and high pollution.

[0003] However, although the round bottle printer has many advantages, it still has some shortcomings in detecting the shape of the bottle in actual application.

[0004] In the working process of the round bottle printer, accurately detecting the shape of the bottle is one of the key prerequisites to ensure high-quality printing.

[0005] At present, most round bottle printers mainly use the following conventional methods in the bottle shape detection link:

[0006] First, the positioning detection method based on mechanical clamps. By designing special mechanical clamps to fix the round bottle, the shape profile and size range of the bottle are roughly judged by the contact between the clamp and the surface of the bottle. Although this method is simple and direct, it has obvious limitations. Mechanical clamps can only adapt to a limited number of standard sizes and shapes of bottles. For bottles with irregular shapes, special curved surfaces or non-standard sizes, it is difficult to achieve precise fitting and positioning, which may cause the bottle to shift or displace during printing, affecting the accuracy of printing and causing pattern misalignment, distortion and other quality problems.

[0007] Second, use a simple photoelectric sensor for shape detection. The photoelectric sensor detects the reflection, shielding, etc. of the light on the bottle surface to obtain part of the shape information of the bottle. However, this method can only obtain rough shape features, and it is difficult to accurately identify the complex shape conditions such as the subtle concave-convex changes and the gradual change of the arc of the bottle surface, so it cannot provide accurate bottle shape data for subsequent printing operations such as height adjustment of the print head and print path planning, which will ultimately affect the perfect presentation of the printed pattern on the bottle surface.

[0008] Third, with the help of part of the visual detection system. Some round bottle printers are equipped with visual detection systems, but most of these systems have relatively simple functions and only perform some basic contour recognition. When facing a bottle surface with complex texture, strong reflection or color close to the background, the visual algorithm is prone to misjudgment and cannot accurately distinguish the real shape details of the bottle, such as being unable to accurately identify the local concave or convex parts on the bottle, so that the print head cannot accurately adjust the height and optimize the path according to the actual shape, reducing the printing quality.

[0009] In summary, the existing round bottle printer is not perfect in bottle shape detection technology and cannot meet the needs of the increasingly diversified round bottle product shapes and high-precision printing. SUMMARY

[0010] The present application provides a control method and system for a multi-nozzle round bottle printer to solve the above technical problems.

[0011] The technical solution of the present application is as follows:

[0012] A control method for a multi-nozzle round bottle printer, comprising the following steps:

[0013] S1, importing a picture to be printed into the system;

[0014] S2, calculating the shape of the bottle and the position of the bottle by the height measuring module and the algorithm;

[0015] S3, calculating the ink drop position on the bottle according to the picture of step S1 by the algorithm;

[0016] S4, converting the ink drop position calculated in step S2 into printing data and transmitting it to the round bottle printer;

[0017] S5, confirming the position of the bottle again, and starting printing after no error is found.

[0018] Preferably, in step S1, the user imports the image file to be printed into the image processing software connected to the computer, and the image processing software analyzes and converts the input image data according to the preset printing parameters, converts it into a print data format suitable for the cylindrical bottle printer, and transmits it to the control system of the cylindrical bottle printer.

[0019] Preferably, in step S2, the height measuring module is specifically an infrared sensor, which obtains the height and shape of the bottle through the folded infrared light.

[0020] Preferably, in step S3, the following sub-steps are further included:

[0021] S31, based on the bottle shape and position information obtained in step S2, the software maps the imported picture onto the three-dimensional surface model of the bottle according to the mapping rule;

[0022] S32, the software will correspond each pixel point in the picture to the actual physical position on the bottle surface according to the actual shape of the bottle and the position of the bottle in the printer coordinate system, establishing a one-to-one correspondence between the two-dimensional picture pixel coordinates and the three-dimensional surface coordinates of the bottle;

[0023] S33, according to the physical characteristics of the nozzle and the printing mode of the printer (such as spiral printing, zoned printing, or line-by-line scanning printing, etc.), the software further determines the specific drop position corresponding to each pixel point on the bottle surface when it is actually converted into inkjet operation through the inkjet drop calculation algorithm and the established coordinate correspondence.

[0024] Preferably, in step S4, the data processing module in the printer control system reads the inkjet drop position information data list generated in step S3, and then encodes and converts it according to the data format that the printer hardware can recognize and process.

[0025] Preferably, step S5 is specifically a pre-printing detection, and the height measuring module works again to quickly re-detect the shape and position of the bottle, obtain the latest bottle position information, and compare it with the initial position information stored in the system memory previously. If the comparison result shows that the position deviation of the bottle in the X, Y, and Z axis directions is within a very small error threshold, it is considered that the bottle position is still accurate and no adjustment is needed, and the printing phase can be directly entered. However, if a large deviation in the bottle position is detected, the system will automatically issue a warning prompt message to inform the user that the bottle position has changed and needs to be adjusted.

[0026] A control system of a multi-nozzle cylindrical bottle printer, comprising a communication module, a data processing module, a signal processing module, and a nozzle control module.

[0027] The communication module is responsible for establishing the interaction of information between each component of the printer and external devices; the data processing module is responsible for comprehensively processing various types of received data to ensure that it can meet the execution requirements of each component of the printer; the signal processing module is responsible for collecting, converting and processing various physical signals involved in the operation of the printer; the nozzle control module, each nozzle corresponds to a nozzle control board, and each nozzle control board receives a unified inkjet synchronization signal and a corresponding print data subset.

[0028] Preferably, the communication module is designed in layers and classified according to different communication objects and data types. When interacting with the computer, a high-level protocol based on the TCP / IP protocol framework is adopted to ensure network communication compatibility and add functions to adapt to large data transmission and real-time control requirements of the printer.

[0029] Preferably, the nozzle control module further comprises a nozzle state monitoring function, which monitors the working state of each nozzle in real time by setting current detection and temperature detection sensors in the nozzle circuit.

[0030] The present application solves the shortcomings of the current round bottle printer in the bottle shape detection link, accurately calculates the shape of the bottle through the height measuring module, and calculates the ink drop position on the bottle through software, achieving precise printing. The present application can adapt to various round bottles of different shapes and sizes. Whether it is a regular cylindrical bottle or a bottle with a certain taper or a special curved surface, it can perform corresponding coordinate conversion and drop calculation according to its specific conditions to ensure that round bottles of different shapes can achieve high-quality printing and meet the printing needs of diversified product packaging, decoration, etc. The operation of the present application is simple and easy to understand, and workers can quickly get started, reducing training costs. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a control method of a multi-nozzle round bottle printer.

[0032] Figure 2 is a control system of a multi-nozzle round bottle printer. DETAILED DESCRIPTION

[0033] To further illustrate the technical means and effects adopted by the present application to achieve the predetermined invention purposes, the exemplary embodiments will be described in detail, which are shown in the drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are only examples of methods and systems consistent with some aspects of the present application as described in the appended claims.

[0034] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0035] Example 1

[0036] like Figure 1 and Figure 2 As shown, the present invention provides a control method for a multi-nozzle round bottle printer, comprising the following steps:

[0037] S1, import the picture to be printed into the system;

[0038] Preferably, in step S1, the user imports the image file to be printed into the image processing software connected to the computer. The image processing software analyzes and converts the input image data according to the preset printing parameters, converts it into a printing data format suitable for the round bottle printer, and transmits it to the control system of the round bottle printer;

[0039] The user first opens the dedicated image processing software on a computer connected to the multi-nozzle round bottle printer. This software features a user-friendly interface and convenient operation, making it easy to perform various image-related operations. Users can navigate to the image file they wish to print on a local storage device (hard drive, USB flash drive, etc.) using a standard file browsing window (such as the file manager in common operating systems). Importing a wide range of image file formats is supported, including common ones like JPEG, PNG, and TIFF, meeting the needs of users seeking to access image material from various design software.

[0040] After selecting an image file, the user clicks the "Import" button (or a similar function button) on the software interface to successfully load the image file into the image processing software. At this point, the software automatically analyzes the basic attribute information of the image file, including the image size (width and height expressed in pixels), color mode (such as common RGB, CMYK, etc.), and original resolution (number of pixels per inch, dpi), etc., and displays it to the user in the corresponding area of ​​the software interface, so that the user can easily confirm whether the initial state of the image meets the expectations.

[0041] S2, through the height measurement module, the algorithm scans the shape and position of the bottle;

[0042] Preferably, in the step S2, the height measuring module is an infrared sensor, which obtains the height and shape of the bottle by the folded-back infrared light;

[0043] More preferably, in the height measuring module, the infrared sensor obtains the time of the folded-back light as the basis for distance measurement. The distance from the infrared sensor to the fixture is fixed as L, and the distances from the infrared sensor to the bottle are expressed as L1, L2, L3,..., Ln. In the set of L1, L2, L3,..., Ln, the mapping to the coordinate system of the printer system forms a shape formed by connecting multiple points, and the shape is the actual shape of the bottle.

[0044] More preferably, in the height measuring module, in the process of detecting the shape of the bottle, on the one hand, the bottle is set as a regular cylinder, and only one side of the bottle needs to be detected. By obtaining the detection result of the side, the complete shape of the bottle can be obtained by rotating 360° or 180°. On the other hand, the bottle is set as an irregular shape. By taking the fixture as the reference, the bottle is divided into the front and the back. The front of the bottle is detected first, and then the side of the bottle is detected. The complete shape of the irregular bottle is obtained by combining the detection results of the front and the side.

[0045] The height measuring module specifically adopts an infrared sensor to realize detection of the shape and position of the bottle. It is composed of an infrared emitting unit, an infrared receiving unit, and a corresponding signal processing circuit, and is installed at a key position related to the bottle placement and printing area inside the printer. It can comprehensively cover the space range where the bottle is located, and ensure accurate acquisition of the related geometric information of the bottle. The infrared emitting unit emits infrared light of a specific frequency and intensity to the area where the bottle is located. After the infrared light meets the surface of the bottle, it is reflected, and part of the light is folded back to the infrared receiving unit along the original route. After the infrared receiving unit receives the folded-back infrared light, it converts the optical signal into an electrical signal and transmits it to the signal processing circuit. The signal processing circuit analyzes and processes the information based on the propagation time and intensity change of the light, thereby obtaining the height and shape related data of the bottle. For example, according to the time difference of the infrared light round trip and the propagation speed of the light in the air, the distance information from the infrared emitting point to each point on the surface of the bottle can be calculated. Through the cooperative work of multiple infrared sensors at different angles and positions, a large amount of distance data points are collected, and then geometric algorithms are used to integrate and analyze these data points, so as to construct a three-dimensional contour model of the surface of the bottle, and further determine the shape of the bottle, such as whether it is a cylinder, a cone or an irregular shape with a special curved surface, and its position in the printer coordinate system. In actual operation, in order to improve the accuracy and stability of the measurement, the height measuring module will perform multiple infrared light emission and reception operations to collect multiple data samples. Then, the original data samples are preprocessed, including removing abnormal data points caused by environmental light interference, sensor noise and other factors (for example, by setting a reasonable distance threshold, data points obviously exceeding the normal measurement range are removed), and filtering the effective data (digital filtering methods such as mean filtering and median filtering can be used to smooth the data curve and reduce fluctuations), to enhance the reliability of the data. The effective data after preprocessing will be the basis for subsequent algorithm processing, used to accurately scan the shape of the bottle and the accurate position information of the bottle, and store these information in the memory of the printer control system, providing key basis for subsequent printing operation

[0046] S3, calculating the inkjet drop position on the bottle by algorithm based on the picture of step S1;

[0047] Preferably, step S3 further includes the following sub-steps:

[0048] S31, based on the bottle shape and position information obtained in step S2, the software will paste the imported picture onto the three-dimensional surface model of the bottle according to the mapping rule;

[0049] After the software obtains the bottle shape and position information determined in step S2, it starts the picture fitting operation. First, a suitable mapping method is selected according to the geometric shape characteristics of the bottle. For example, for a cylindrical bottle, a cylindrical coordinate system is established with the bottle's axis as the reference, the bottle surface is unfolded as a rectangular plane, and the imported picture is mapped onto the unfolded plane according to certain proportional relationships and coordinate mapping rules. For a conical or more complex shaped bottle, more complex surface unfolding and coordinate transformation algorithms are used to achieve the preliminary fitting of the picture to the bottle surface.

[0050] During this process, the software considers the position information of the bottle to perform translation, rotation, and other adjustment operations on the picture fitting, ensuring that the picture can accurately correspond to the actual surface position of the bottle placed in the printer. For example, if the bottle has a certain translation amount in the horizontal direction relative to the origin of the printer coordinate system, the software will correspondingly perform translation correction on the horizontal coordinate mapping of the picture. If the bottle has a rotation angle around a certain coordinate axis, the software will use the corresponding rotation matrix transformation to adjust the angle of the picture to match the actual posture of the bottle, ultimately achieving the approximate fitting of the picture to the bottle surface in three-dimensional space, laying the foundation for subsequent accurate coordinate correspondence.

[0051] S32, according to the actual shape of the bottle and the position of the bottle in the printer coordinate system, the software will correspond each pixel point in the picture to the actual physical position on the bottle surface, establishing a one-to-one correspondence between the two-dimensional picture pixel coordinates and the three-dimensional surface coordinates of the bottle.

[0052] Based on the above picture fitting, the software further performs fine coordinate correspondence operations. For each point on the bottle surface, according to the actual shape of the bottle and its position in the printer coordinate system, each pixel point in the picture is accurately corresponded to the actual physical position on the bottle surface, establishing a strict one-to-one correspondence.

[0053] For different shapes of bottles, the specific corresponding method is different. For example, for a cylindrical bottle, after the picture is fitted to the bottle surface to expand a rectangular plane, the angle coordinate is defined along the circumferential direction of the bottle, and the height coordinate is defined along the axial direction of the bottle. For any pixel point in the picture, the horizontal pixel coordinate (assuming the picture width direction is the x pixel coordinate) is mapped to the circumferential angle coordinate of the bottle surface expanded rectangular plane according to a certain proportional relationship, and the vertical pixel coordinate is mapped to the height coordinate of the bottle surface expanded rectangular plane according to the corresponding proportion, and then the picture pixel coordinate is converted into the actual three-dimensional surface coordinate of the bottle through the conversion relationship between the cylindrical coordinate system and the three-dimensional Cartesian coordinate system. For other complex shape bottles, according to their specific curved surface geometry and coordinate transformation rules, the accurate correspondence of each pixel point to the three-dimensional coordinate of the bottle surface is realized through calculation, so that each pixel point can find a unique physical position on the bottle surface, providing accurate coordinate basis for accurate calculation of ink drop position;

[0054] S33, according to the physical characteristics of the nozzle and the printing mode of the printer, the software further determines the specific drop position corresponding to each pixel point on the bottle surface when it is actually converted into ink operation through the ink drop calculation algorithm and the established coordinate correspondence. According to the physical characteristics of the nozzle and the printing mode of the printer, the software uses a special ink drop calculation algorithm in combination with the above established coordinate correspondence to further determine the specific drop position corresponding to each pixel point on the bottle surface when it is actually converted into ink operation.

[0055] For the arrangement of the nozzle, if the nozzle is arranged in a straight line, the nozzles are distributed at equal intervals along the axial direction of the bottle with a nozzle spacing d. The software will determine the axial area range of each nozzle according to the nozzle number and the spacing (the calculation method is as described above, and factors such as the expansion of the upper and lower coverage range caused by the nozzle jet angle can be considered for adjustment), and then determine which nozzle is responsible for the axial area corresponding to each pixel point; if the nozzle is arranged in a circle (commonly used for full-circumferential printing of the circumferential surface of the bottle), the software will determine the distribution angle interval of the nozzle on the circumference and the radius distance r0 of the nozzle relative to the axial line of the bottle. Through these parameters, the starting and ending angle range of each nozzle in the circumferential direction of the bottle is determined to determine which nozzle is responsible for the circumferential direction corresponding to each pixel point.

[0056] Detailed understanding of the single nozzle hole distribution, nozzle hole usually in the nozzle surface in a regular array, set nozzle hole in the nozzle transverse direction spacing is Δx1, longitudinal direction spacing is Δy1, while determining the number of each nozzle hole rule (for example from the top left corner begin by row or column sequentially numbered). In the calculation of ink drop, according to the pixel position to be printed and the distribution characteristics of the nozzle, find the most suitable nozzle for the corresponding ink drop. For example, for a pixel point in the coordinate position (x1, y1) after the bottle surface mapping (here is the coordinate after the bottle surface mapping, has been mapped to the actual position of the bottle surface), by comparing the coordinates and nozzle spacing and numbering relationship (can use simple coordinate range judgment or more complex distance optimization algorithm, select the nozzle closest to the pixel and meet the jet angle conditions), determine which nozzle is responsible for the ink drop.

[0057] At the same time, considering the influence of nozzle spacing on the continuity of printing, especially in the multi nozzle collaborative work, the adjacent nozzle jet area needs to have a certain overlap, in order to ensure that the printing pattern will not appear fault or color uneven phenomenon at the nozzle junction. Through experiment or theoretical calculation to determine the appropriate nozzle overlap ratio (generally in 10%-30% or so, according to the nozzle performance and printing quality requirements adjustment), and in the calculation of ink drop position, according to the overlap requirements adjust the effective jet range of nozzle and the division and cooperation relationship of adjacent nozzle, ensure the uniform and continuous ink coverage of the whole bottle surface. Through this series of complex and fine calculation process, finally determine the specific drop position corresponding to each pixel point when converted into ink operation on the bottle surface, and generate a detailed data list containing all the ink drop position information, stored in the system memory for later use, ready for the subsequent printing data conversion and transmission.

[0058] S4, the ink drop position calculated by step S2 is converted into printing data and transmitted to the round bottle printer;

[0059] S5, confirm the bottle position again, and start printing after no error.

[0060] Preferably, the step S5 is specifically for pre printing detection, the height measuring module works again, quickly re detects the shape and position of the bottle, obtains the latest bottle position information, and compares it with the initial position information stored in the system memory before, if the comparison result shows that the position deviation of the bottle in X, Y and Z axis direction is within a very small error threshold, it is considered that the bottle position is still accurate, and no adjustment is needed, and the printing stage can be directly entered; however, if it is detected that the bottle position has a large deviation, the system will automatically issue a warning prompt information, informing the user that the bottle position has changed, and the bottle placement position needs to be adjusted again.

[0061] Preferably, in the step S4, the data processing module in the printer control system reads the inkjet drop position information data list generated in the step S3, and then encodes and converts it into a data format that can be recognized and processed by the printer hardware.

[0062] Preferably, in the step S3, the inkjet drop calculation method is as follows:

[0063] First, the specific arrangement of the nozzles on the printer is determined, which can be in a straight line, a circle, or a matrix, etc.

[0064] For example, in the case of a straight line arrangement, the nozzles are distributed at equal intervals along the axial direction of the bottle. Let the nozzle spacing be d. When calculating the inkjet drop position, the axial height range of each nozzle is determined according to the nozzle number and the spacing. Assuming there are n nozzles and the bottle height is H, the axial height range of the i-th nozzle can be roughly determined as from (i-1)*d to i*d.

[0065] For nozzles arranged in a circle, the angular interval of the nozzles on the circle needs to be determined, denoted as θ0. For example, if the nozzles are uniformly distributed on the circle, there are m nozzles, and θ0=360 / m degrees. In addition, the radius distance r of the nozzles relative to the bottle axis is also determined. With these parameters, the starting and ending angle range of each nozzle in the circumferential direction of the bottle can be determined, providing a basis for subsequent calculation of the specific nozzle and drop position corresponding to each pixel point.

[0066] Let the nozzle spacing in the transverse direction be Δx1 and in the longitudinal direction be Δy1. The numbering rule of each nozzle is also determined. When calculating the inkjet drop position, according to the pixel position to be printed and the nozzle distribution characteristics, the nozzle responsible for ejecting the ink droplet corresponding to the pixel is found. For example, for a pixel point with a coordinate position (x1, y1) after mapping on the bottle surface, by comparing the coordinates with the nozzle spacing and numbering relationship, it is determined which nozzle is responsible for ejecting the ink droplet. This may involve simple coordinate range judgment or more complex distance optimization algorithms.

[0067] Considering the influence of nozzle spacing on printing continuity, especially when multiple nozzles work together, the ejection areas of adjacent nozzles need to have a certain overlap to ensure that the printed pattern does not have gaps or color unevenness at the intersection of the nozzles. Through experiments or theoretical calculations, a suitable nozzle overlap ratio (generally around 10%-30%, adjusted according to nozzle performance and printing quality requirements) is determined. When calculating the inkjet drop position, the effective ejection range of the nozzles and the cooperation relationship between adjacent nozzles are adjusted according to the overlap requirements to ensure uniform and continuous ink coverage on the entire bottle surface.

[0068] Spiral printing:

[0069] In the spiral printing mode, the nozzle moves along the spiral trajectory on the surface of the bottle and sprays ink. When calculating the ink drop position, the position of the nozzle at each time and the corresponding ink drop point need to be determined according to the parametric equation of the spiral. The basic parameters of the spiral include pitch (the axial distance between adjacent spirals, denoted as p), radius (the radius of the nozzle rotating around the axis of the bottle, generally equal to the radius of the bottle plus a suitable distance from the nozzle to the surface of the bottle, denoted as R), and initial angle (the initial angle of the nozzle on the circumference of the bottle when printing starts, denoted as θ1), etc.

[0070] For a given time t (which can be determined according to the nozzle movement speed and printing progress), the angular coordinate θ(t) of the nozzle in the circumferential direction of the bottle can be calculated by the formula θ(t) = θ1 + (2π*v1*t / (2πR)) (where v1 is the movement speed of the nozzle in the circumferential direction), and the height coordinate h(t) in the axial direction can be calculated by h(t) = v2*t (where v2 is the movement speed of the nozzle in the axial direction). Combined with the pixel coordinate and bottle surface coordinate correspondence obtained by mapping the surface of the bottle, the actual position of the pixel point to be printed on the surface of the bottle at each time t is determined, and then the appropriate nozzle nozzle and corresponding ink drop position are found, so that the ink droplets can be accurately sprayed on the corresponding position of the bottle surface along the spiral trajectory, realizing the effect of continuous spiral printing.

[0071] Zoning printing:

[0072] The surface of the bottle is divided into several different regions (for example, according to the height and circumferential angle range of the bottle, such as dividing the axial direction of the bottle into several intervals, and the circumferential direction into several angular intervals, forming a grid of sub-regions), and each region is responsible for printing by a specific nozzle or nozzle combination.

[0073] For each sub-region, according to its boundary range and the pixel points to be printed in the region, the specific nozzle and ink drop position corresponding to each pixel point in the region are determined according to the arrangement and nozzle distribution rules of the nozzle. For example, a sub-region has an angular range from θ2 to θ3 in the circumferential direction of the bottle and a height range from h1 to h2 in the axial direction. Combined with the circumferential and axial distribution of the nozzle, the nozzle covering the region is found, and for each pixel point in the region, the corresponding drop position is calculated to ensure smooth connection between the printing of each sub-region and complete and unified printing pattern on the entire surface of the bottle.

[0074] Line-by-line scanning printing:

[0075] The inkjet is scanned along the axial direction of the bottle row by row, which is similar to the application of the line-by-line printing mode of the flatbed printer to the surface of the bottle. The starting and ending positions of each row are determined (determined according to the circumference of the bottle and the coverage range of the nozzle), and for each row, the ink drop landing position corresponding to each pixel point on the row is calculated according to the nozzle hole distribution and spacing. For example, starting from the bottom of the bottle, the height coordinate of the first row is h3 (usually a reference height at the bottom of the bottle), and the nozzle scans from the starting angle θ4 to the ending angle θ5 along the circumferential direction (determined according to the coverage angle of the nozzle and the circumference of the bottle). During this process, according to the angle coordinate position of each pixel point on the row and the nozzle hole distribution, it is determined which nozzle hole sprays ink drops at which position, and the printing of the entire bottle surface is completed row by row, ensuring the printing continuity and pattern integrity between each row.

[0076] A control system of a multi-nozzle round bottle printer, comprising a communication module, a data processing module, a signal processing module and a nozzle control module.

[0077] The communication module is responsible for the interaction of information between the components of the printer and external devices.

[0078] It adopts multiple communication modes and interfaces to ensure that the data between different modules in the system can be accurately and efficiently transmitted. At the physical level, the mainboard and the computer are connected through optical fiber network cables to form a local area network environment, ensuring long-distance, high-speed and stable data transmission, meeting the interaction needs of a large amount of image data and control instructions in the printing process. At the same time, within the printer, the mainboard, the trolley board and the expansion board are connected through a specially designed high-speed data bus, and the nozzle control board and the mainboard also have independent communication lines. Each connection line adopts a wiring method with strong anti-interference ability to reduce the influence of external electromagnetic interference on communication and ensure communication quality.

[0079] In order to realize efficient and reliable communication between each board, the communication module is designed for different communication objects and data types, and the protocol is layered and classified. When interacting with the computer, a high-level protocol based on the TCP / IP protocol framework is adopted. On the basis of ensuring the compatibility of network communication, functions suitable for large data transmission and real-time control requirements of the printer are added, such as adding a print task identification field in the data packet header, which facilitates the motherboard to quickly identify and classify the received data as image data, control instructions or state query requests, etc. For the communication between the internal boards of the printer, a lightweight, message-oriented custom protocol is adopted. This protocol specifies the format of the message in detail, including the message start identifier, message length, message type, specific data content, and check code part. Through this rigorous message format definition, each board can accurately parse and encapsulate the received and sent messages, avoiding misreading and incorrect parsing during data transmission, and ensuring the accuracy of communication.

[0080] The computer communicates with the motherboard, and the computer as the initiator of the print task sends the data such as the prepared image to be printed by the user and the set print parameters to the motherboard through the communication module. The communication module first encapsulates these data according to the above custom protocol on the computer side, converts them into network data packets, and then sends them to the corresponding network interface of the motherboard through the optical fiber network cable. After receiving the data packet, the communication module of the motherboard performs strict verification and unpacking operations to verify the integrity and correctness of the data packet. If the verification is passed, the data in the data packet is extracted and transmitted to the data processing module for subsequent processing. If errors are found in the data packet, a retransmission request will be sent to the computer until the correct data is received. At the same time, the motherboard can also feedback the real-time state information of the printer to the computer through the communication link, which is convenient for users to understand the working condition of the printer in real time.

[0081] The communication between the motherboard and the car board and the expansion board is established. During the printing process, the motherboard needs to transmit print data to the car board, such as image data segments corresponding to each nozzle divided according to the nozzle layout, and motion control instructions. These information will be encapsulated into messages according to the internal custom protocol and sent to the corresponding car board through the high-speed data bus. After receiving the message, the car board parses it and performs the corresponding operation according to the instruction, and feeds back the position signal and working state information collected by itself to the motherboard, and sends them in the specified message format, realizing bidirectional information interaction, ensuring the accurate positioning and motion coordination of the nozzles during printing.

[0082] The communication between the nozzle control boards is established, the nozzle control board mainly receives the key information such as ink jet control instructions and synchronization signals from the mainboard, the communication interface can listen to the messages sent by the mainboard in real time, once the instruction related to itself is received, the corresponding ink jet control operation is immediately analyzed and executed. For example, according to the ink jet time point, ink drop size, jet frequency and corresponding color channel information specified in the instruction, the nozzle is accurately controlled to jet ink, and the working state of the nozzle can also be fed back to the mainboard, so that corresponding maintenance measures can be taken in time to ensure the normal operation of the printing work;

[0083] The signal processing module is responsible for comprehensive processing of various types of received data to ensure that it meets the execution requirements of the printer components.

[0084] When the communication module sends the data from the computer or other board card to the data processing module, the legality of the data is checked and preprocessed first. For image data, it is verified whether the format meets the standard supported by the printer, if the format is not consistent, format conversion or user prompt to prepare a suitable image file is attempted; at the same time, the resolution, color mode and other parameters of the image data are checked, if the resolution is too high, it may exceed the physical printing capacity of the printer, appropriate downsampling processing is performed to optimize the data amount, if the color mode is inconsistent with the color configuration of the nozzle, the color conversion algorithm is called to convert it to the color mode adapted to the nozzle;

[0085] After the preprocessing is completed, for the print image data, the data processing module will divide and distribute the image data according to the number of nozzles of the printer and the physical layout of the nozzles. The printer of the present application has at least 16 nozzles, then the entire image is evenly divided into 16 regions in the circumferential direction, the image data of each region is distributed to the corresponding nozzle control board, ensuring that each nozzle is responsible for printing a part of the image, and the parts can seamlessly connect together to form a complete print pattern. In the distribution process, the image data will be further converted into a format that can be directly recognized by the nozzle, the color information of the image will be decomposed and encoded according to the color channel of the nozzle, and the resolution and physical spacing of the nozzle and other parameters will be combined to determine the detailed information of the nozzle ink jet position and ink jet amount of each pixel point, to generate a dedicated print data subset for each nozzle, and make full preparation for the subsequent accurate ink jet printing;

[0086] In order to cope with the temporary storage and efficient calling of a large amount of data in complex printing tasks, the data processing module has a perfect data caching mechanism.

[0087] A special data cache area is opened in the memory, and the data is classified and stored according to the data type and processing stage, which is convenient for quick retrieval and use. For example, when receiving a large image file from a computer, the data will be temporarily stored in the cache area, and pre-processing will be performed while receiving to avoid the situation that the data is not processed in time or lost due to too large data volume; during printing, the print data subsets of each nozzle that have been processed but have not been sent to the nozzle control board will also be stored in the cache area in order, and the corresponding data will be pushed in time according to the printing progress of the nozzle to ensure the continuity of printing. At the same time, the data cache management also involves data updating, cleaning and other operations. When a printing task is completed, the relevant cache data is cleaned in time to release the memory space and prepare for the data processing needs of the next printing task, ensuring the efficiency and stability of the entire data processing process.

[0088] The signal processing module is responsible for collecting, converting and processing various physical signals involved in the operation of the printer, providing accurate real-time feedback information and key control basis for the control system.

[0089] Various types of sensors are installed at key positions of the printer to collect different signals. For example, a grating sensor is installed on the track of the nozzle movement. Through the cooperation of the grating ruler and the photoelectric detection element, the position information of the nozzle in the X, Y and Z axis directions can be accurately detected. The principle is that the light signal changes periodically by using the shielding and transmission changes of the grating stripes on the grating ruler, and the photoelectric detection element converts the light signal into an electric signal to obtain the displacement information of the nozzle. A flow sensor is provided at the ink pump and ink pipeline to monitor the flow of ink and convert the changes in physical pressure or flow rate generated by the ink flow into an electric signal output. A temperature sensor is also provided inside the printer to detect the temperature changes of the nozzle, motor and other key components in real time, and the temperature value is also fed back in the form of an electric signal. The original electric signals collected by these sensors are usually analog signals, which are converted into digital signals by the analog-digital conversion circuit in the signal processing module for subsequent digital signal processing and analysis.

[0090] The signal after filtering and amplification will be sent to a special signal analysis algorithm module for further processing. For example, for the position signal of the printhead from the grating sensor, the algorithm is used for differential calculation, integral operation and other processing, combined with the mechanical structure parameters of the printer, the actual position coordinates of the printhead at each time and the motion parameters such as speed and acceleration are accurately calculated, and according to the preset printing track and the current printing progress, whether the printhead deviates from the predetermined position, the motion is abnormal or not is judged. Based on these analysis results, the signal processing module will generate corresponding control signals, such as when the printhead position deviation is found, the control signal for adjusting the speed and direction of the printhead moving motor is generated and sent to the main control board, and the main control board drives the motor to perform corresponding position correction operation; at the same time, according to the printhead position signal and the printing task information from the printing data processing module, the inkjet synchronization signal is generated according to the specific algorithm, which accurately specifies the key parameters such as the time and position of each printhead to start inkjet and the frequency of inkjet, to ensure that each printhead can realize synchronous and accurate inkjet printing on the surface of the round bottle, and ensure the quality and integrity of the printed pattern.

[0091] The printhead control module, each printhead corresponds to a printhead control board, and each printhead control board receives a unified inkjet synchronization signal and a corresponding printing data subset. Under the coordination of the inkjet synchronization signal, each printhead control board will strictly control the printhead to perform inkjet operation according to the same time reference and frequency requirement, to ensure that the ink droplets ejected by each printhead can accurately converge at the corresponding position on the surface of the round bottle, forming a continuous, uniform and complete pattern.

[0092] At the same time, the printhead control module also has the function of printhead state monitoring, by setting current detection, temperature detection and other sensors in the printhead circuit, the working state of each printhead is monitored in real time, for example, when a printhead appears to be blocked, it shows that the printhead current is abnormal or the inkjet is not smooth, etc. The corresponding printhead control board can detect the abnormal signal in time and feed back the information to the main board, and the main board can take corresponding maintenance measures to avoid affecting the quality and progress of the whole printing task due to the failure of individual printhead;

[0093] In order to adapt to different printing materials, printing requirements and ink characteristics, the nozzle control module supports flexible adjustment and optimization of various parameters of the nozzle. Users can set parameters such as drop size, ejection frequency, distance between nozzle and bottle surface, etc. through the operation interface of the printer. These setting information will be transmitted to the corresponding nozzle control board through the communication module. The nozzle control board adjusts the output signal of the drive circuit according to the received parameters, thereby changing the ink ejection behavior of the nozzle. For example, when printing high-precision patterns, the drop size and ejection frequency can be appropriately reduced to improve the clarity and color delicacy of the patterns. When pursuing high-speed printing, the drop size and ejection frequency can be appropriately increased, but at the same time the adhesion of the ink and the pattern quality need to be considered. Through continuous testing and optimization of nozzle parameters, the best parameter combination that meets different printing requirements is found, and high-quality and diversified bottle printing effects are achieved.

[0094] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present application. Any modification, equivalent change and modification of the above embodiments made in accordance with the technical essence of the present application shall still fall within the scope of the technical solution of the present application.

Claims

1. A control method for a multi-nozzle round bottle printer, characterized in that: The steps include: S1, import the image to be printed into the control system of the round bottle printer; S2: The algorithm scans the shape and position of the bottle through the altimeter module. The altimeter module is specifically an infrared sensor. It performs multiple infrared light transmission and reception operations to collect multiple sets of data samples. These raw data samples are then preprocessed, including removing abnormal data points caused by ambient light interference and sensor noise, and filtering the valid data. The preprocessed valid data serves as the basis for subsequent algorithm processing to accurately scan the shape and accurate position of the bottle. Multiple infrared sensors at different angles and positions work together to collect a large number of distance data points. These data points are then integrated and analyzed using geometric algorithms to construct a three-dimensional contour model of the bottle surface, thereby determining the bottle's shape. S3, calculating the inkjet landing point on the bottle through an algorithm based on the image in step S1; S4, converting the inkjet landing point position calculated in step S3 into printing data and transmitting it to the round bottle printer; S5, confirm the bottle position again, and start printing after it is correct; The step S3 further includes the following sub-steps: S31, based on the bottle shape and position information obtained in step S2, the software fits the imported image onto the three-dimensional surface model of the bottle according to mapping rules; At step S32, the software maps each pixel in the image to the actual physical location on the bottle's surface based on the bottle's actual shape and its position in the printer's coordinate system, establishing a one-to-one correspondence between the two-dimensional image pixel coordinates and the three-dimensional surface coordinates of the bottle. S33, based on the physical characteristics of the nozzle and the printer's printing mode, the software uses an inkjet landing point calculation algorithm and established coordinate correspondence to further determine the specific landing point position corresponding to each pixel point on the bottle surface when it is actually converted into an inkjet operation; In step S3, the inkjet landing point position is calculated as follows: First, determine the specific arrangement layout of the nozzles on the printer. In the case of linear arrangement, the nozzles are evenly spaced along the axial direction of the bottle. When calculating the inkjet landing point, the nozzle serial number and spacing are used to determine the axial area of ​​the bottle that each nozzle is responsible for, and then determine which nozzle is responsible for the axial area corresponding to each pixel point. For the nozzles arranged in a circle, determine the distribution angle interval of the nozzles on the circumference and the radius distance of the nozzles relative to the axis of the bottle. These parameters are used to determine the starting and ending angle range of each nozzle in the circumferential direction of the bottle, so as to determine which nozzle is responsible for the circumferential direction corresponding to each pixel point. The nozzle holes are arranged regularly on the surface of the nozzle. The array arrangement is used to determine the numbering rule of each nozzle. When calculating the inkjet landing point, the nozzle that sprays the ink droplet corresponding to the pixel point is found based on the pixel point position to be printed and the nozzle point distribution characteristics. For the coordinate position of a certain pixel point after mapping on the bottle surface, the nozzle that is responsible for spraying the ink droplet is determined by comparing the coordinates with the nozzle point spacing and numbering relationship. The spraying areas of adjacent nozzles need to have a certain overlap. The appropriate nozzle overlap ratio is determined through experiments or theoretical calculations. When calculating the inkjet landing point, the effective spraying range of the nozzle and the division of labor and cooperation between adjacent nozzles are adjusted according to the overlap requirements to ensure uniform and continuous inkjet coverage on the entire bottle surface. Specifically, step S5 includes a pre-printing detection, in which the height measurement module performs a second operation to quickly re-detect the shape and position of the bottle, obtain the latest bottle position information, and compare it with the initial position information previously stored in the system memory. If the comparison results show that the position deviations of the bottle in the X, Y, and Z axis directions are all within a very small error threshold range, the bottle position is considered to be still accurate and no adjustment is required, and the printing stage can be directly entered; However, if a large deviation is detected in the bottle position, the system will automatically issue an alarm prompt message to inform the user that the bottle position has changed and the bottle placement needs to be readjusted.

2. The control method of a multi-nozzle round bottle printer according to claim 1, characterized in that: In step S1, the user imports the image file to be printed into the image processing software connected to the computer. The image processing software parses and converts the input image data according to the preset printing parameters, converts it into a printing data format suitable for the round bottle printer, and transmits it to the control system of the round bottle printer.

3. The control method of a multi-nozzle round bottle printer according to claim 1, characterized in that: In step S4, the data processing module in the printer control system reads the inkjet landing point position information data list generated in step S3, and then performs encoding conversion according to a data format that can be recognized and processed by the printer hardware.

4. A control system for a multi-nozzle round bottle printer for implementing the control method according to any one of claims 1 to 3, characterized in that: Including communication module, data processing module, signal processing module and nozzle control module; The communication module is responsible for information exchange between the various components of the printer and with external devices; the data processing module is responsible for comprehensive processing of various types of data received to ensure that they meet the execution requirements of the various components of the printer; the signal processing module is responsible for collecting, converting and processing various physical signals involved in the operation of the printer; the nozzle control module, each nozzle corresponds to a nozzle control board, and each nozzle control board receives a unified inkjet synchronization signal and its corresponding printing data subset.

5. The control system of a multi-nozzle round bottle printer according to claim 4, characterized in that: The communication module has designed protocols in layers and categories for different communication objects and data types. When interacting with a computer, it adopts a high-level protocol based on the TCP / IP protocol framework. On the basis of ensuring network communication compatibility, it adds functions that adapt to the large data transmission and real-time control requirements of the printer.

6. The control system of a multi-nozzle round bottle printer according to claim 4, characterized in that: The nozzle control module also includes a nozzle status monitoring function, which monitors the working status of each nozzle in real time by setting current detection and temperature detection sensors in the nozzle circuit.

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