Surface jet printing method, device and system for special-shaped product

Abstract

The invention relates to the technical field of ink-jet printing, and particularly discloses a surface jet printing method, device and system for a special-shaped product, and the method comprises the steps: scanning the to-be-jet-printed special-shaped product to determine the surface profile of the special-shaped product; according to the surface profile, a jet printing track of a spray head and the surface to be sprayed is determined, and a preset distance is always kept between the jet printing track and the surface of the special-shaped product; and controlling the spray head to perform spray printing on the to-be-sprayed surface of the special-shaped product along the spray printing track. Therefore, the jet printing track of the nozzle and the to-be-jetted surface is determined according to the obtained surface profile, and the preset distance is always kept between the jet printing track and the surface of the special-shaped product. The problem of coating deposition amount difference caused by distance change between the spray head and the surface of a product is effectively solved, and uniform distribution of the coating thickness in different areas is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of inkjet printing, and in particular to a surface printing method, device and system for special-shaped products. Background Art

[0002] In modern industrial manufacturing, the surface coating printing technology of special-shaped products has been widely used. This technology aims to give specific functional or decorative coatings to various products with unique shapes and complex structures to meet diverse market needs. With the continuous advancement of science and technology, printing technology has made significant progress in accuracy, speed and material adaptability.

[0003] However, despite these advances, there are still some unavoidable technical challenges. In the actual process of printing coatings on the surface of special-shaped products, due to the different surface shapes of special-shaped products, there are various curvatures, concave-convex structures and angle changes. This makes it difficult to keep the distance and angle between the nozzle and the product surface constant during the printing process, resulting in differences in the amount of coating deposited in different areas, resulting in uneven thickness of the coating on the surface of special-shaped products. For example, in the curved part, the distance between the nozzle and the surface may suddenly increase, resulting in the dispersion of the landing points of the coating spray and the thinning of the coating; while in the concave area, the distance between the nozzle and the surface decreases, and the coating is easy to accumulate, resulting in increased thickness.

[0004] This uneven surface thickness seriously affects the quality and performance of the product. Uneven coating thickness may cause product appearance defects and affect its decorative effect; in terms of functional coating, it may cause local protective performance, wear resistance or conductivity to fail to meet the expected standards, reducing product reliability and service life. Therefore, solving the problem of uneven coating thickness on the surface of special-shaped products is of vital importance to improving product quality and enhancing market competitiveness, and is a key technical bottleneck that needs to be broken through in this field. Summary of the invention

[0005] The present invention provides a surface printing method, device and system for special-shaped products, aiming to improve the uniformity of the surface coating of the special-shaped products.

[0006] In one aspect, the present invention provides a surface printing method for a special-shaped product, comprising:

[0007] Scanning the special-shaped product to be printed to determine the surface profile of the special-shaped product;

[0008] According to the surface profile, determining the printing trajectory between the nozzle and the surface to be sprayed, wherein the printing trajectory always maintains a preset distance from the surface of the special-shaped product;

[0009] The nozzle is controlled to print on the surface to be printed of the special-shaped product along the printing track.

[0010] In some embodiments, scanning the special-shaped product to be printed to determine the surface profile of the special-shaped product includes:

[0011] Performing visual scanning on the special-shaped product to determine the surface profile of the special-shaped product;

[0012] Or, a drawing file of the special-shaped product is obtained, and a surface contour of the special-shaped product is determined according to the drawing file.

[0013] In some embodiments, determining the printing trajectory of the nozzle and the surface to be sprayed according to the surface profile includes:

[0014] Determining a preset distance between the nozzle and the surface to be sprayed of the special-shaped product according to the data information of the surface profile;

[0015] Acquire a plurality of contour coordinates corresponding to the surface contour, each of the contour coordinates including coordinate information corresponding to different positions of the special-shaped product;

[0016] Based on a preset conversion rule, the plurality of contour coordinates are converted into corresponding printing tracks according to the preset distance.

[0017] In some embodiments, determining the preset distance between the nozzle and the surface to be sprayed of the special-shaped product according to the data information of the surface profile includes:

[0018] calculating the curvature of the surface profile;

[0019] The preset distance between the spray head and the surface to be sprayed of the special-shaped product is determined according to the curvature of the surface profile.

[0020] In some embodiments, the converting of the plurality of contour coordinates into corresponding printing trajectories based on a preset conversion rule and according to the preset distance includes:

[0021] Calculating the trajectory coordinates of the printing position corresponding to the target contour coordinates according to the coordinate information of the target contour coordinates and the preset distance, wherein the target contour coordinates are any one of the multiple contour coordinates;

[0022] Calculating the trajectory angle change of the printing position corresponding to the target contour coordinates according to two adjacent contour coordinates of the target contour coordinates;

[0023] The trajectory coordinates and trajectory angle changes of the printing position corresponding to each contour coordinate are calculated to obtain the printing trajectory corresponding to the special-shaped product, and the distance between each contour coordinate and the corresponding trajectory coordinate is maintained at the same preset distance.

[0024] In some embodiments, the printing track includes a plurality of printing track segments, each of which includes a feathering region and a non-feathering region;

[0025] The controlling the nozzle to print on the surface to be printed of the special-shaped product along the printing track comprises:

[0026] Controlling the nozzle to spray ink on the surfaces to be sprayed corresponding to the multiple printing trajectory segments in sequence along the printing trajectory;

[0027] In the non-feathering area, controlling the nozzle to spray ink on the surface to be sprayed corresponding to the printing track segment;

[0028] In the feathering area, the nozzle is controlled to perform wedge-shaped feathering on the surface to be sprayed corresponding to the printing trajectory segment, so as to connect every two printing trajectory segments in the multiple printing trajectory segments.

[0029] In some embodiments, the multiple printing trajectory segments include a first printing trajectory segment and a second printing trajectory segment, the first printing trajectory segment is any one of the multiple printing trajectory segments, and the second printing trajectory segment is a trajectory segment after the second printing trajectory segment;

[0030] The controlling the nozzle to perform wedge-shaped feathering processing on the surface to be sprayed corresponding to the printing track segment includes:

[0031] In the feathering area of ​​the first printing trajectory segment, reducing the amount of ink sprayed by the nozzle on the surface to be sprayed corresponding to the feathering area of ​​the first printing trajectory segment;

[0032] Adjusting the relative position between the nozzle and the surface to be sprayed, and taking the feathering area of ​​the first printing trajectory segment as the printing starting point to print the second printing trajectory segment;

[0033] At the starting point of the printing, the amount of ink applied by the nozzle to the surface to be sprayed corresponding to the feathering area of ​​the first printing trajectory segment is increased until the non-feathering area of ​​the second printing trajectory segment is reached.

[0034] In some embodiments, after the step of converting the plurality of contour coordinates into corresponding printing trajectories based on a preset conversion rule and according to the preset distance, the surface printing method of the special-shaped product further includes:

[0035] Calculate the distance between every two contour coordinates to obtain a first distance;

[0036] Calculate the distance between every two trajectory coordinates to obtain a second distance;

[0037] determining a speed ratio based on the first distance and the second distance;

[0038] The movement speed of the nozzle for printing on the surface of the special-shaped product is determined according to the speed ratio.

[0039] In a second aspect, the present invention further provides a surface printing device for a special-shaped product, the surface printing device for a special-shaped product comprising:

[0040] A scanning unit, used for scanning the special-shaped product to be printed to determine the surface profile of the special-shaped product;

[0041] A determination unit, used to determine a printing trajectory between the nozzle and the surface to be sprayed according to the surface profile, wherein the printing trajectory always maintains a preset distance from the surface of the special-shaped product;

[0042] A control unit is used to control the nozzle to print on the surface to be sprayed of the special-shaped product along the printing track.

[0043] In a third aspect, the present invention further provides a surface printing system for special-shaped products. The surface printing system for special-shaped products includes a memory and a processor, the memory stores a computer program, and the processor calls the computer program to implement the steps of the surface printing method for special-shaped products disclosed in the present application.

[0044] In an embodiment of the present application, the surface contour of the special-shaped product to be printed can be determined by scanning the special-shaped product to be printed; based on the surface contour, the printing trajectory between the nozzle and the surface to be printed is determined, and the printing trajectory always maintains a preset distance from the surface of the special-shaped product; the nozzle is controlled to print on the surface to be printed of the special-shaped product along the printing trajectory.

[0045] The beneficial effects of the present invention are as follows: first, by scanning the special-shaped product to be printed to determine its surface profile, the shape characteristics of the product surface can be accurately obtained, including various curvatures, concave-convex structures, angle changes and other information. This provides an accurate data basis for the subsequent printing trajectory planning, thereby avoiding the problem of uneven coating caused by blind printing without understanding the shape of the product. The printing trajectory of the nozzle and the surface to be sprayed is determined according to the acquired surface profile, and the printing trajectory and the surface of the special-shaped product always maintain a preset distance. This means that the nozzle can adjust its position in real time according to the specific shape of the product surface to ensure that the distance between the nozzle and the product surface remains relatively constant during the entire printing process. In this way, in the curved surface part, the coating thinning caused by the increase in the distance between the nozzle and the surface to be sprayed can be controlled; in the concave area, the distance between the nozzle and the surface to be sprayed can be controlled to prevent the coating accumulation caused by too small a distance. Thereby effectively solving the difference in coating deposition caused by the change in the distance between the nozzle and the product surface, and realizing the uniform distribution of coating thickness in different areas. Controlling the nozzle to print on the surface of the special-shaped product along the planned printing trajectory can ensure the accuracy and stability of the printing process. This allows the coating to be evenly covered on the surface of the product, avoiding uneven thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the structure of a printing system provided by one embodiment of the present invention;

[0047] Figure 2 A schematic flow chart of a method for printing on the surface of a special-shaped product provided by an embodiment of the present invention;

[0048] Figure 3 Another schematic flow chart of a method for surface printing of a special-shaped product provided by an embodiment of the present invention.

[0049] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] The scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] It should be noted that the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0052] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0053] In order to enable those skilled in the art to better understand the solution of the present application, the application environment of the solution of the present application is first described. The surface printing method of the special-shaped product provided by the present application can be applied to Figure 1 The system architecture shown.

[0054] See also Figure 1 , Figure 1 1 is a schematic diagram of a system architecture of the printing system 100 provided in the embodiment of the present application. Figure 1 As shown, the printing system 100 may include a scanning detection device 101, an operation device 102, and a control processor 103. The control processor 103 may communicate with the scanning detection device 101 and the operation device 102 respectively.

[0055] The scanning and detecting device 101 can be used to scan and detect the special-shaped product to determine the surface contour of the special-shaped product. The scanning and detecting device 101 can be a scanning and detecting device placed inside the control processor 103 to directly determine the surface contour of the special-shaped product by visually scanning the special-shaped product. The scanning and detecting device 101 can also be a scanning and detecting device that exists independently of the control processor 103, generates CAD drawings, 3D model files and other drawing files, and sends a receipt document to the control processor 103 to determine the surface contour corresponding to the special-shaped product.

[0056] The operation device 102 may include a nozzle, a motion device, an ink supply device, etc. The operation device 102 can complete the printing operation of the special-shaped product to be printed.

[0057] The control processor 103 has powerful computing and data processing capabilities, and can coordinate the work of various components to execute multiple steps such as determining the printing trajectory of the nozzle and the surface to be sprayed according to the surface contour and controlling the nozzle to print on the surface to be sprayed of the special-shaped product along the printing trajectory.

[0058] The above-mentioned printing system 100 is an example of a printing system 100 involved in a surface printing method for a special-shaped product disclosed in this application. It is intended to better explain the various steps of the surface printing method for a special-shaped product when describing the surface printing method for a special-shaped product of this application, and does not limit this application.

[0059] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0060] The invention provides a surface spray printing method for special-shaped products.

[0061] See also Figure 2 , Figure 2 1 is a schematic flow chart of a method for printing a surface of a special-shaped product disclosed in an embodiment of the present application. The method for printing a surface of a special-shaped product can be applied to a printing system. Figure 2 As shown, the surface printing method of the special-shaped product may include the following steps.

[0062] Step 201 : Scan the special-shaped product to be printed to determine the surface profile of the special-shaped product.

[0063] The surface profile can be the shape and boundary features of the outer surface of the special-shaped product. It includes various shape changes such as undulations, bends, and concavities on the product surface, as well as the transition between different parts. By describing the surface profile, the appearance characteristics of the product can be accurately reflected.

[0064] The special-shaped products can be those products with irregular shapes and do not have common standard geometric shapes. These products may have complex and unique shapes, for example, with special curves, asymmetrical structures, complex three-dimensional shapes, or be composed of multiple parts with different shapes.

[0065] It should be noted that scanning of special-shaped products to be printed can be performed using specific scanning technologies or equipment such as lasers and optical sensors, so as to conduct comprehensive inspection and measurement of products with special and irregular shapes to be printed, thereby obtaining their surface shape and feature information, providing accurate basic data for subsequent printing processes.

[0066] For example, in automobile manufacturing, some parts with special shapes; in electronic products, shells with non-standard shapes can be regarded as special-shaped products. Before printing the surface coating of these products, these parts with special shapes can be scanned to determine their surface contours so that subsequent printing operations can be carried out accurately to ensure the quality and effect of the printing.

[0067] In some specific implementations, scanning the special-shaped product to be printed to determine the surface contour of the special-shaped product can be performed by visually scanning the special-shaped product to determine the surface contour of the special-shaped product.

[0068] It should be noted that in some practical operation methods, to determine the surface contour of the special-shaped product to be printed, the method of visual scanning of the special-shaped product can be used. Visual scanning can usually be achieved by using optical equipment and related image processing technology to take pictures, measure and analyze the surface of the special-shaped product, so as to obtain detailed information about its shape, size, curvature, etc., so as to accurately depict the surface contour of the product.

[0069] For example, high-precision industrial cameras, laser scanners and other equipment can be used to photograph or scan special-shaped products from different angles, and then the acquired data can be processed and calculated through computer software to finally generate a contour model or data that can accurately reflect the surface shape of the product. This visual scanning method has the advantages of non-contact, fast, and accurate, and can effectively obtain the complex surface features of special-shaped products, providing a reliable basis for subsequent printing work.

[0070] Alternatively, in some other specific implementations, scanning the special-shaped product to be printed to determine the surface contour of the special-shaped product can also be performed by obtaining a drawing file of the special-shaped product and determining the surface contour of the special-shaped product based on the drawing file.

[0071] It should be noted that in some other practical operation modes, in order to determine the surface contour of the special-shaped product to be printed, it is also possible to obtain a drawing file of the special-shaped product and then clarify its surface contour based on the drawing file. The drawing file may be a detailed design drawing of the special-shaped product created using professional drawing software or design tools. The drawing file may include a two-dimensional plan view, a three-dimensional model view, and precise information such as the marked size, shape, and angle of the special-shaped product.

[0072] For example, CAD drawings, 3D model files, etc. generated during the product design phase can be used as drawing files. By reading and analyzing the data in these drawings, the surface contour information of the special-shaped product can be directly obtained without additional measurement or scanning. This method can save time and cost in determining the surface contour and improve work efficiency when complete and accurate drawing files are already available.

[0073] Step 202: Determine the printing trajectory of the nozzle and the surface to be printed according to the surface profile.

[0074] The printing track always maintains a preset distance from the surface of the special-shaped product.

[0075] The printing trajectory may be a path followed by the nozzle when performing a printing operation, and the printing trajectory may be a trajectory that maintains the same preset distance as the surface contour of the special-shaped product.

[0076] It should be noted that, based on the surface profile shape and features of the special-shaped product obtained through scanning, the specific route that the nozzle should move when printing on the surface of the product can be planned and calculated.

[0077] The preset distance may be a preset spacing distance between the nozzle and the surface to be printed, and the preset distance may be a distance value determined according to the curvature of the surface contour of the special-shaped product. The preset distance may be a distance value for surface printing of special-shaped products with different surface contours in order to achieve a preset printing effect.

[0078] It should be noted that when facing a surface with a large curvature, if the preset distance is too small, the paint sprayed from the nozzle may be overly concentrated in a local area, resulting in an overly thick coating and accumulation, affecting the uniformity and quality of the printing. If the preset distance is too large, the paint will be overly dispersed in the process of reaching the surface, causing the coating to become thinner, and the expected coverage effect may not be achieved. On the contrary, for a flatter surface with a smaller curvature, appropriately reducing the preset distance can make the paint more concentrated and evenly distributed, forming a coating of moderate thickness. However, if the preset distance is too small, accumulation may still occur; if the preset distance is too large, the coating may be too thin.

[0079] In some embodiments, determining the printing trajectory between the nozzle and the surface to be sprayed according to the surface profile may be determining a preset distance between the nozzle and the surface to be sprayed according to the surface profile after determining the surface profile of the special-shaped product. After determining the preset distance, determining the printing trajectory between the nozzle corresponding to the surface profile and the surface to be sprayed according to the preset distance.

[0080] Step 203: Control the nozzle to print on the surface to be printed of the special-shaped product along the printing trajectory.

[0081] After the printing track is determined, the surface of the special-shaped product to be printed can be printed according to the printing track. Specifically, after the printing track for the surface contour of the special-shaped product and the preset distance between the printing track and the surface to be printed are determined, the nozzle can be accurately directed and controlled to move along the printing track, and the printing operation can be performed during the movement.

[0082] For example, in the process of printing a rugby-shaped special-shaped product, after scanning and obtaining its surface contour, it can be found that its two ends are sharper and the middle part is more rounded. For the surface contour of this product, the determined printing trajectory may start from the tip of one end and gradually move to the middle along the arc of the surface. At the tip part, due to the large surface curvature, the preset distance may be set to a smaller value, such as 5 cm, to ensure that the paint sprayed by the nozzle can accurately cover the tip area to avoid excessive dispersion of the paint and cause the coating to become thinner. When the nozzle moves to the middle rounded part, due to the relatively flat surface and small curvature, the preset distance may be adjusted to 8 cm, so that the paint can be evenly distributed in this area to prevent the paint from accumulating and making the coating too thick. The entire printing trajectory always maintains the preset distance set according to the surface contour characteristics of the position at different positions on the product surface, thereby achieving a uniform and accurate printing effect.

[0083] For another example, a special-shaped part with a complex concave-convex structure needs to be printed. In the convex part, the surface curvature is larger, and the preset distance is set to 4 cm to ensure that the paint can be concentrated on the convex area. In the concave part, the preset distance may be increased to 6 cm to prevent excessive concentration of paint and cause the coating to be too thick. The nozzle moves along the designed trajectory and maintains the corresponding preset distance at each position to complete high-quality printing.

[0084] exist Figure 2 In the described method embodiment, the surface contour of the special-shaped product to be printed can be determined by scanning the special-shaped product to be printed; according to the surface contour, the printing trajectory between the nozzle and the surface to be printed is determined, and the printing trajectory and the surface of the special-shaped product always maintain a preset distance; the nozzle is controlled to print on the surface to be printed on the special-shaped product along the printing trajectory. In this way, the printing trajectory between the nozzle and the surface to be printed is determined according to the acquired surface contour, and the printing trajectory and the surface of the special-shaped product always maintain a preset distance. The difference in coating deposition caused by the change in the distance between the nozzle and the product surface is effectively solved, and the uniform distribution of coating thickness in different areas is achieved. Controlling the nozzle to print on the surface to be printed on the special-shaped product along the planned printing trajectory can ensure the accuracy and stability of the printing process. This allows the coating to be evenly covered on the surface of the product, avoiding uneven thickness.

[0085] See also Figure 3 , Figure 3FIG. 1 is a flow chart of another method for printing a surface of a special-shaped product disclosed in an embodiment of the present application. The method for printing a surface of a special-shaped product can be applied to a chip testing system. Figure 3 As shown, the surface printing method of the special-shaped product may include the following steps.

[0086] Step 301: Scan the special-shaped product to be printed to determine the surface profile of the special-shaped product.

[0087] The specific content of step 301 can refer to the explanation of step 201 and will not be repeated here.

[0088] Step 302: Determine a preset distance between the nozzle and the surface to be sprayed of the special-shaped product according to the data information of the surface profile.

[0089] The preset distance may be a preset distance determined according to data information of the surface profile of the special-shaped product, and the preset distance may be a distance maintained by the nozzle when printing the line of the surface to be sprayed on the special-shaped product.

[0090] The data information may be characteristic information of the surface profile of the special-shaped product, and the data information may include detailed characteristic information of the surface shape, curvature, degree of concavity, etc. of the special-shaped product. The data information may be used to calculate the preset distance between the nozzle and the surface to be sprayed in order to achieve uniform and accurate spray printing effect at different positions of the nozzle.

[0091] It should be noted that, for special-shaped products with different surface shapes, curvatures or degrees of concavity and convexity, a predetermined preset distance between the nozzle and the surface to be sprayed of the special-shaped product can be set according to the data information of the surface contour corresponding to the special-shaped product.

[0092] As an example, determining the preset distance between the nozzle and the surface to be sprayed of the special-shaped product based on the data information of the surface profile may include: calculating the curvature of the surface profile; and determining the preset distance between the nozzle and the surface to be sprayed of the special-shaped product based on the curvature of the surface profile.

[0093] Among them, the curvature of the surface profile of the special-shaped product is negatively correlated with the preset distance.

[0094] Specifically, when the curvature of the surface profile is large, it means that the surface is severely curved. In order to ensure the uniformity and accuracy of the printing, the preset distance usually needs to be set smaller. This can bring the nozzle closer to the surface, reduce the dispersion of the paint during the spraying process, ensure that there is enough paint deposition in areas with large curvature, and avoid thinning of the coating. On the contrary, when the curvature of the surface profile is small, that is, the surface is relatively flat, the preset distance can be appropriately increased. Because in this case, the nozzle is a little farther away from the surface, the spraying and distribution of the paint can still be relatively uniform, and there will be no excessive concentration or accumulation. By reasonably determining this preset distance, the distribution of the paint sprayed from the nozzle on the product surface can be effectively controlled, the uneven thickness of the coating can be reduced, and the printing quality can be improved.

[0095] For example, for a spherical special-shaped product, the preset distance should be smaller at the part with large curvature of the spherical top; while the preset distance can be larger in the relatively flat area close to the circle.

[0096] Step 303: Obtain multiple contour coordinates corresponding to the surface contour.

[0097] Each contour coordinate includes coordinate information corresponding to different positions of the special-shaped product.

[0098] The contour coordinates may be coordinate information corresponding to any number of points in the surface contour of the special-shaped product. The any number of points may be randomly determined points in the surface contour, or the any number of points may be contour key points in the surface contour.

[0099] The key points of the contour can be specific points with significant features or important significance in the surface contour, which can significantly affect the overall shape and structure of the product and are representative for describing the geometric features of the product surface. These points can roughly outline the contour shape of the product, such as the vertex of the surface, the end point of the edge, the extreme point of the concave or convex part, etc. For example, for a special-shaped product similar to a cone, its vertex and the edge point of the bottom circle can be regarded as the key points of the contour; for a part with a complex surface, the sudden change point of the curvature of the surface may be the key point of the contour.

[0100] Step 304: Based on a preset conversion rule and according to a preset distance, a plurality of contour coordinates are converted into corresponding printing tracks.

[0101] The conversion rule may be a formula for converting the acquired multiple contour coordinates from points to lines.

[0102] It should be noted that the conversion rule can convert any one of the multiple contour coordinates into the coordinates and angle information of the trajectory path through the determined product contour coordinates. Specifically, the converted contour coordinates can be determined by calculating the angle difference between each contour coordinate and the reference point coordinates, and combined with the modulus length of each contour coordinate, and the corresponding trajectory angle change can be calculated. After determining the converted contour coordinates and trajectory angle change, the corresponding trajectory path can be calculated based on the trajectory coordinates and trajectory angle changes corresponding to the multiple contour coordinates, and the trajectory path can be a printing trajectory for printing special-shaped products.

[0103] After determining the surface of the special-shaped product to be sprayed and scanning it, a series of multiple contour coordinates can be obtained, such as (X1, Z1), (X2, Z2), (X3, Z3), etc. Then, these contour coordinates are calculated and converted using the preset conversion rules. In the conversion process, the preset distance plays a key role. The preset distance determines the expected distance between the nozzle and the product surface during the printing process, and this distance will affect the converted trajectory coordinate value. For example, for a specific contour coordinate (Xn, Zn), the coordinate position (xn, zn) of the corresponding trajectory coordinate and the corresponding angle change information cn are calculated according to the conversion formula. The coordinate information and angle information of the trajectory coordinate constitute a trajectory coordinate (xn, zn, cn) on the printing trajectory. After all contour coordinates are converted and processed in this way, a complete printing trajectory that meets the preset distance requirements can be obtained.

[0104] In some specific implementations, based on a preset conversion rule and according to a preset distance, converting a plurality of contour coordinates into corresponding printing trajectories may include:

[0105] (1) Calculating the trajectory coordinates of the printing position corresponding to the target contour coordinates according to the coordinate information of the target contour coordinates and the preset distance, where the target contour coordinates are any one of the multiple contour coordinates.

[0106] The trajectory coordinates may be the coordinate values ​​of any position of the printing trajectory passed by the nozzle during the process of printing the special-shaped product, and the trajectory coordinates may be the coordinate values ​​corresponding to the contour coordinates. Each contour coordinate may have a corresponding trajectory coordinate, and the correspondence between each contour coordinate and the corresponding trajectory coordinate may be based on the conversion of coordinate values ​​in different coordinate systems. The difference between the trajectory coordinates and the contour coordinates is based on the expected thickness of the pigment to be printed and the height of the nozzle.

[0107] It should be noted that the trajectory coordinates of the printing position corresponding to the target contour coordinates are calculated based on the coordinate information of the target contour coordinates and the preset distance, which is to convert the coordinates of the target contour into another coordinate system to determine the printing trajectory that extends outward at a certain preset distance from the surface to be sprayed of the special-shaped product.

[0108] (2) According to two contour coordinates adjacent to the target contour coordinate, the trajectory angle change of the printing position corresponding to the target contour coordinate is calculated.

[0109] The track angle change may be the change in the angle formed by the moving direction of the nozzle from the target contour coordinate position to its two adjacent contour coordinate positions in the printing track.

[0110] It should be noted that after determining multiple contour coordinates, the two contour coordinates adjacent to the target contour coordinate can be determined. By analyzing the relative position relationship between these three coordinates, the change in the angle formed by the movement direction of the nozzle when the nozzle moves from two adjacent coordinates to the target coordinate during the printing process can be calculated. In this way, the movement path (printing trajectory) of the nozzle can be planned more accurately. Because when printing on the surface of special-shaped products, the shape of the surface is irregular, and the nozzle needs to continuously adjust the movement direction according to the changes in the surface. By calculating the change in trajectory angle, the angle adjustment that the nozzle needs to make at each position can be predicted in advance, so that the printing trajectory is more in line with the contour of the product surface, ensuring the quality and accuracy of the printing.

[0111] (3) Calculate the trajectory coordinates and trajectory angle changes of the printing position corresponding to each contour coordinate to obtain the printing trajectory corresponding to the special-shaped product, and maintain the same preset distance between each contour coordinate and the corresponding trajectory coordinate.

[0112] For all the multiple contour coordinates of the surface contour of the special-shaped product obtained, the trajectory coordinates and trajectory angle changes are calculated as described in the previous steps (1) and (2) to obtain the trajectory coordinates and trajectory angle changes corresponding to each contour coordinate, and the relevant data of all points are integrated to form a complete printing path that can accurately cover the surface of the special-shaped product.

[0113] Specifically, the printing trajectory corresponding to the special-shaped product can be calculated by calculating the trajectory coordinates corresponding to each contour coordinate, and then determining the corresponding printing trajectory according to the multiple trajectory coordinates.

[0114] Exemplarily, multiple contour coordinates can be defined as (X1, Z1), (X2, Z2), (X3, Z3), etc. It can be known that each contour coordinate has a corresponding trajectory coordinate. The multiple trajectory coordinates corresponding to the multiple contour coordinates can be first defined as unknown (x1, y1, z1), (x2, y2, z2), (x3, y3, z3), etc., and the preset distance is d.

[0115] Multiple contour coordinates can be converted into corresponding trajectory coordinates, which may include coordinate position and angle change information of the trajectory coordinates. The conversion formula is as follows:

[0116] x1=COS(ATAN2(X1,Z1)-ATAN2((X2-X0),(Z2-Z0)))*SQRT(X1 2 +Z1 2 )

[0117] z1=-SIN(ATAN2(X1,Z1)-ATAN2((X2-X0),(Z2-Z0)))*SQRT(X1 2 +Z1 2 )

[0118] c1=180(1-ATAN2((X2-X0),(Z2-Z0)) / π)

[0119] Among them, (x1, z1) are the coordinate values ​​of the coordinate positions of the converted trajectory coordinates in different dimensions, and c1 can be the angle change information determined after the trajectory coordinates are converted and calculated.

[0120] By analogy, the trajectory coordinates and trajectory angle changes of all contour coordinates are calculated to finally obtain a complete printing trajectory.

[0121] Exemplarily, calculating the trajectory coordinates and trajectory angle changes corresponding to a certain contour coordinate may include the following steps: Assume X0=0, Z0=0, X1=3, Z1=4, X2=6, Z2=8.

[0122] First, calculate ATAN2(X1, Z1) and ATAN2((X2-X0), (Z2-Z0)): ATAN2(X1, Z1) = ATAN2(3, 4) ≈ 0.927; ATAN2((X2-X0), (Z2-Z0)) = ATAN2(6, 8) ≈ 0.927. Then calculate X1 and Z1: X1 = COS(0.927-0.927)*SQRT(3^2+4^2) = COS(0)*5 = 5; Z1 = -SIN(0.927-0.927)*SQRT(3^2+4^2) = -SIN(0)*5 = 0. Finally, calculate C1: C1 = 180*(1-0.927 / π) ≈ 32.7°, and finally determine the corresponding trajectory coordinates as (5, 0, 32.7°).

[0123] Step 305 , controlling the nozzle to spray ink on the surfaces to be sprayed corresponding to the multiple printing trajectory segments in sequence along the printing trajectory.

[0124] The printing track may include multiple printing track segments, and the number of the multiple printing track segments may be determined according to the curvature, concavity, etc. of the printing track.

[0125] It should be noted that since the printing track is the track corresponding to the surface to be sprayed of the special-shaped product, the printing track is a curve corresponding to the surface of the special-shaped product, and the curvature of the printing track as a curve is positively correlated with the number of printing track segments. When the curvature of the printing track is larger, the printing track can be divided into as many printing track segments as possible to improve the printing effect. When the curvature of the printing track is smaller, the printing track can be printed as a whole.

[0126] In some embodiments, after the printing trajectory is determined, the printing trajectory can be divided into multiple printing trajectory segments.

[0127] It should be noted that dividing the printing track into multiple printing track segments can better adapt to the complex changes of the product surface. For example, the product surface may have areas with different heights, parts with obvious curvature changes, or locations that require different printing precision. Through reasonable division, more targeted printing parameters can be set for each track segment, such as nozzle movement speed, inkjet volume, and preset distance.

[0128] Specifically, the division can be based on the geometric features of the surface, such as curvature, slope, and concave-convex degree; it can also be based on the difference in printing requirements, such as some areas need thicker coatings or higher color accuracy. Dividing the printing trajectory into multiple segments helps to achieve a more sophisticated, accurate and efficient printing process, thereby improving product quality and production efficiency.

[0129] After determining multiple printing trajectory segments of the printing trajectory, the print head can be controlled to perform inkjet operations on the surfaces to be printed corresponding to the multiple different printing trajectory segments in turn according to the planned printing trajectory, so as to achieve complete and accurate printing on the entire surface of the special-shaped product.

[0130] For example, suppose the printing track of a special-shaped product is divided into three sections, the first section is the top curved part of the product, the second section is the inclined part of the side, and the third section is the flat part of the bottom. The control system will first let the nozzle spray ink along the first section of the track, and then spray ink along the second section of the track, and finally the third section of the track, so as to ensure that the entire product surface is evenly and accurately printed with the required pattern or coating.

[0131] Step 306: In the non-feathering area, the nozzle is controlled to spray ink on the surface to be sprayed corresponding to the printing trajectory segment.

[0132] It should be noted that after the printing track is divided, at the junction between each two printing track segments, the printing process will cause the parameters such as the nozzle movement speed, inkjet volume or preset distance to be different, resulting in inconsistent coating thickness between each two printing tracks. Therefore, the printing track during the printing operation can be divided into corresponding feathering areas and non-feathering areas, so as to perform inkjet on the basin label of special-shaped products based on the different area divisions of the printing track.

[0133] The non-feathering area is an area corresponding to the edge area in each printing track segment after the printing track is segmented.

[0134] In the non-feathering area of ​​each printing trajectory segment, the nozzle can be directly controlled to perform inkjet operation on the corresponding surface to be sprayed along the printing trajectory segment.

[0135] Step 307: In the feathering area, the nozzle is controlled to perform wedge-shaped feathering processing on the surface to be sprayed corresponding to the printing trajectory segment, so as to connect every two printing trajectory segments in the multiple printing trajectory segments.

[0136] The feathering area may be the connecting area between every two printing track segments, and the feathering area generally refers to the area in the printing area that needs special treatment so that the printing effect gradually transitions from clear and obvious to blurred and soft.

[0137] When the printing area of ​​the nozzle enters the surface to be printed corresponding to the feathering area, the nozzle can be controlled to perform a special treatment on the surface to be printed, namely wedge-shaped feathering treatment. The purpose of this treatment is to enable two adjacent segments of the multi-segment printing trajectory to be naturally and smoothly connected together, eliminating the obvious boundaries or discontinuities that may appear.

[0138] Among them, the wedge-shaped feathering treatment can be that the inkjet mode of the nozzle in the feathering area will gradually change, for example, the inkjet volume will gradually decrease from a large amount, or the nozzle movement speed will gradually increase from a slow speed, forming a wedge-shaped transition effect, making the connection between two adjacent printing trajectory segments softer and more uniform, thereby improving the printing quality and visual effect.

[0139] In some specific embodiments, the multiple printing trajectory segments may include a first printing trajectory segment and a second printing trajectory segment, the first printing trajectory segment is any one of the multiple printing trajectory segments, and the second printing trajectory segment is a trajectory segment after the second printing trajectory segment.

[0140] The step of controlling the nozzle to perform wedge-shaped feathering processing on the surface to be sprayed corresponding to the printing trajectory segment may include: (1) in the feathering area of ​​the first printing trajectory segment, reducing the amount of ink sprayed by the nozzle on the surface to be sprayed corresponding to the feathering area of ​​the first printing trajectory segment.

[0141] In the feathering area where the first printing track segment is close to the end and is about to connect with the second printing track segment, the amount of ink sprayed by the nozzle can be gradually reduced. It is easy to understand that reducing the amount of ink sprayed by the nozzle in the feathering area is to "pave the way" for the upcoming transition, so that the color or coating thickness at the end of the first printing track segment gradually becomes lighter and thinner.

[0142] For example, the nozzle originally operates with a stable and large amount of ink. After the printing area reaches the feathering area, the ink amount gradually decreases, and can be reduced from 10 ml of ink per second at the beginning to 5 ml per second.

[0143] (2) The relative position between the nozzle and the surface to be sprayed is adjusted, and the feathering area of ​​the first printing trajectory segment is used as the printing starting point to print the second printing trajectory segment.

[0144] After finishing the printing of the feathering area of ​​the first printing track, the relative position of the nozzle and the surface to be sprayed can be adjusted, and the feathering area of ​​the first printing track segment is used as a new starting point to start printing the second printing track segment.

[0145] (3) At the starting point of printing, the amount of ink applied by the nozzle to the surface to be sprayed corresponding to the feathering area of ​​the first printing trajectory segment is increased until the ink reaches the non-feathering area of ​​the second printing trajectory segment.

[0146] After the feathering area of ​​the first printing track segment is used as the printing starting point of the second printing track segment, the ink volume of the printing work can be gradually increased directly at the printing starting point. That is, from this new starting point, that is, the feathering area of ​​the first printing track segment, the ink volume of the ink jetting head is gradually increased, so as to form a wedge-like transition effect, thereby improving the printing effect of the transition from the first printing track segment to the second printing track segment.

[0147] For example, the ink volume is increased from 5 ml per second to 10 ml per second until the non-feathering area of ​​the second printing track segment is entered, so that the two printing tracks can be naturally and smoothly connected together without abrupt boundaries or obvious differences in color or thickness. Thus, through the fine control of the ink volume and the nozzle position, the wedge-shaped feathering process between the printing track segments is achieved, which improves the quality and aesthetics of the printing.

[0148] In other embodiments, after the step of converting multiple contour coordinates into corresponding printing trajectories based on a preset conversion rule and according to a preset distance, the surface printing method of special-shaped products also includes: calculating the distance between every two contour coordinates to obtain a first distance; calculating the distance between every two trajectory coordinates to obtain a second distance; determining a speed ratio based on the first distance and the second distance; and determining the movement speed of the nozzle for printing on the surface of the special-shaped product based on the speed ratio.

[0149] The first distance may refer to the straight-line distance between each two adjacent contour coordinates in the original plurality of contour coordinates. The first distance may be used to reflect the actual spacing between contour points on the surface of the special-shaped product before the printing trajectory conversion is performed.

[0150] The second distance may be the straight-line distance between every two adjacent track coordinates in the converted printing track. Different from the first distance, the second distance is the spacing calculated on the track after the conversion rule processing.

[0151] The speed ratio may be a ratio calculated by comparing the first distance with the second distance. The speed ratio may be used to reflect the proportional relationship between the profile coordinate spacing and the track coordinate spacing.

[0152] The movement speed can be the speed at which the nozzle moves when printing on the surface of a special-shaped product. This movement speed can be used to determine the movement speed so that the movement of the nozzle can adapt to the changes in the spacing of the contour and trajectory, thereby achieving uniform and accurate printing.

[0153] It should be noted that the movement speed of the nozzle is precisely controlled according to the original contour of the product and the converted printing trajectory. By calculating the speed ratio between the first distance and the second distance, and then determining the movement speed of the nozzle based on the speed ratio, it can be ensured that the nozzle can reasonably adjust the movement speed according to the changes in the surface shape and trajectory during the printing process.

[0154] For example, if the second distance of a certain section becomes larger than the first distance, the speed ratio increases, and the movement speed of the nozzle in this section will increase accordingly; conversely, if the second distance becomes smaller, the speed ratio decreases, and the movement speed of the nozzle decreases. This can avoid insufficient printing in the part with larger spacing or excessive printing in the part with smaller spacing, thereby improving the quality and consistency of printing.

[0155] exist Figure 3 In the described method embodiment, the surface contour of the special-shaped product to be printed can be determined by scanning the special-shaped product to be printed; according to the surface contour, the printing trajectory between the nozzle and the surface to be printed is determined, and the printing trajectory and the surface of the special-shaped product always maintain a preset distance; the nozzle is controlled to print on the surface to be printed on the special-shaped product along the printing trajectory. In this way, the printing trajectory between the nozzle and the surface to be printed is determined according to the acquired surface contour, and the printing trajectory and the surface of the special-shaped product always maintain a preset distance. The difference in coating deposition caused by the change in the distance between the nozzle and the product surface is effectively solved, and the uniform distribution of coating thickness in different areas is achieved. Controlling the nozzle to print on the surface to be printed on the special-shaped product along the planned printing trajectory can ensure the accuracy and stability of the printing process. This allows the coating to be evenly covered on the surface of the product, avoiding uneven thickness.

[0156] It should be understood that the same or corresponding information in the above different embodiments can be referenced to each other.

[0157] It should be understood that although Figure 2 , Figure 3 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 2 and Figure 3 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0158] The above is only a specific implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A surface printing method for a special-shaped product, characterized in that: include: Scanning the special-shaped product to be printed to determine the surface profile of the special-shaped product; According to the surface profile, determining the printing trajectory between the nozzle and the surface to be sprayed, wherein the printing trajectory always maintains a preset distance from the surface of the special-shaped product; The nozzle is controlled to print on the surface to be printed of the special-shaped product along the printing track.

2. The surface printing method of special-shaped products according to claim 1, characterized in that: The scanning of the special-shaped product to be printed to determine the surface profile of the special-shaped product includes: Performing visual scanning on the special-shaped product to determine the surface profile of the special-shaped product; Or, a drawing file of the special-shaped product is obtained, and a surface contour of the special-shaped product is determined according to the drawing file.

3. The surface printing method of special-shaped products according to claim 1, characterized in that: Determining the printing trajectory of the nozzle and the surface to be printed according to the surface profile includes: Determining a preset distance between the nozzle and the surface to be sprayed of the special-shaped product according to the data information of the surface profile; Acquire a plurality of contour coordinates corresponding to the surface contour, each of the contour coordinates including coordinate information corresponding to different positions of the special-shaped product; Based on a preset conversion rule, the plurality of contour coordinates are converted into corresponding printing tracks according to the preset distance.

4. The surface printing method of a special-shaped product according to claim 3, characterized in that: Determining the preset distance between the nozzle and the surface to be sprayed of the special-shaped product according to the data information of the surface profile includes: calculating the curvature of the surface profile; The preset distance between the spray head and the surface to be sprayed of the special-shaped product is determined according to the curvature of the surface profile.

5. The surface printing method of special-shaped products according to claim 3, characterized in that: The method of converting the plurality of contour coordinates into corresponding printing trajectories based on a preset conversion rule and according to the preset distance includes: Calculating the trajectory coordinates of the printing position corresponding to the target contour coordinates according to the coordinate information of the target contour coordinates and the preset distance, wherein the target contour coordinates are any one of the multiple contour coordinates; Calculating the trajectory angle change of the printing position corresponding to the target contour coordinates according to two adjacent contour coordinates of the target contour coordinates; The trajectory coordinates and trajectory angle changes of the printing position corresponding to each contour coordinate are calculated to obtain the printing trajectory corresponding to the special-shaped product, and the distance between each contour coordinate and the corresponding trajectory coordinate is maintained at the same preset distance.

6. The surface printing method of special-shaped products according to claim 1, characterized in that: The printing track includes a plurality of printing track segments, each of which includes a feathering area and a non-feathering area; The controlling the nozzle to print on the surface to be printed of the special-shaped product along the printing track comprises: Controlling the nozzle to spray ink on the surfaces to be sprayed corresponding to the multiple printing trajectory segments in sequence along the printing trajectory; In the non-feathering area, controlling the nozzle to spray ink on the surface to be sprayed corresponding to the printing track segment; In the feathering area, the nozzle is controlled to perform wedge-shaped feathering on the surface to be sprayed corresponding to the printing trajectory segment, so as to connect every two printing trajectory segments in the multiple printing trajectory segments.

7. The surface printing method of a special-shaped product according to claim 6, characterized in that: The multiple printing trajectory segments include a first printing trajectory segment and a second printing trajectory segment, the first printing trajectory segment is any one of the multiple printing trajectory segments, and the second printing trajectory segment is a trajectory segment after the second printing trajectory segment; The controlling the nozzle to perform wedge-shaped feathering processing on the surface to be sprayed corresponding to the printing track segment includes: In the feathering area of ​​the first printing trajectory segment, reducing the amount of ink sprayed by the nozzle on the surface to be sprayed corresponding to the feathering area of ​​the first printing trajectory segment; Adjusting the relative position between the nozzle and the surface to be sprayed, and taking the feathering area of ​​the first printing trajectory segment as the printing starting point to print the second printing trajectory segment; At the starting point of the printing, the amount of ink applied by the nozzle to the surface to be sprayed corresponding to the feathering area of ​​the first printing trajectory segment is increased until the non-feathering area of ​​the second printing trajectory segment is reached.

8. The surface printing method of a special-shaped product according to any one of claims 1 to 7, characterized in that: After the step of converting the plurality of contour coordinates into corresponding printing tracks based on the preset conversion rule and according to the preset distance, the surface printing method of the special-shaped product further includes: Calculate the distance between every two contour coordinates to obtain a first distance; Calculate the distance between every two trajectory coordinates to obtain a second distance; determining a speed ratio based on the first distance and the second distance; The movement speed of the nozzle for printing on the surface of the special-shaped product is determined according to the speed ratio.

9. A surface printing device for special-shaped products, characterized in that: include: A scanning unit, used for scanning the special-shaped product to be printed to determine the surface profile of the special-shaped product; A determination unit, used to determine a printing trajectory between the nozzle and the surface to be sprayed according to the surface profile, wherein the printing trajectory always maintains a preset distance from the surface of the special-shaped product; A control unit is used to control the nozzle to print on the surface to be sprayed of the special-shaped product along the printing track.

10. A surface printing system for special-shaped products, characterized in that: The surface printing system for special-shaped products includes a memory and a processor, the memory stores a computer program, and the processor calls the computer program to implement the steps of the surface printing method for special-shaped products as described in any one of claims 1 to 8.

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