A tire sidewall engraving device, method and readable storage medium

Abstract

The present application provides a tire sidewall engraving device, method and readable storage medium. The device includes a loading layer, a scanning layer and an engraving layer arranged in sequence from bottom to top, wherein: the tire to be processed is placed at the loading layer; a double-track synchronous gantry slide is provided at the scanning layer, and along the direction facing the tire sidewall on the slide, a plurality of 3D sensors for collecting the point cloud of the tire sidewall are provided; a laser engraving head is provided at the engraving layer, and the laser engraving head is used to project etching laser onto the engraving position on the tire sidewall under the drive of a controller. The present invention uses laser to engrave on the side of the already formed tire, which can effectively avoid the occurrence of poor operation caused by manual operation, accurately perform laser engraving on the position of the tire sidewall that needs to be engraved, improve the tire production quality, and at the same time greatly improve the engraving efficiency of the tire sidewall, which is beneficial to ensuring the consistency of the product.

Description

Technical Field

[0001] The present application relates to the technical field of tire side pattern engraving, and more particularly, to a tire sidewall engraving device, method and readable storage medium. Background Art

[0002] Automobile tires are safety-related products. For reasons such as product life cycle management and aesthetic appearance improvement, it is necessary to engrave (subtractive processing: including engraving, grinding, etc.) each tire sidewall more and more.

[0003] In terms of product life cycle management, it is necessary to form markings on the tire side, such as cycle codes, transfer codes, DOT codes, markings, two-dimensional codes, etc. In the past, tire manufacturing enterprises used the method of inlaying separately made inserts in the tire mold to form sidewall markings. However, the production of inserts is relatively cumbersome, and regular replacement is prone to inlay number errors, or due to poor inlay quality, the tire quality may be affected.

[0004] In terms of aesthetic appearance improvement, for some luxury cars, ceremonial vehicles and specific types of vehicles, it is necessary to decorate the tire side differently from other parts of the outer tire surface, which can add beauty. Among them, the tire decorated with white rubber is commonly known as the white sidewall tire. The previous process was to manually grind off the cover rubber on the decorative film to expose the white sidewall, and it was not easy to ensure that the white rubber surface was delicate and smooth. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a tire sidewall engraving device, method and readable storage medium, which can improve the quality of tire production.

[0006] The embodiments of the present application also provide a tire sidewall engraving device, which includes a loading layer, a scanning layer and an engraving layer arranged in sequence from bottom to top, wherein:

[0007] The tire to be processed is placed at the loading layer;

[0008] A double-track synchronous gantry slide is provided at the scanning layer, and one or more 3D sensors for collecting the point cloud of the tire sidewall are provided on the slide along the direction facing the tire sidewall;

[0009] A laser engraving head is provided at the engraving layer, and the laser engraving head is used to irradiate the etching laser to the engraving position on the tire sidewall under the drive of a drive signal generated by the controller based on the point cloud of the tire sidewall.

[0010] In a second aspect, the embodiments of the present application also provide a tire sidewall engraving method applicable to the above-mentioned device. The method is applied to a controller and includes the following steps:

[0011] S1. Determine the target tire sidewall point cloud based on the initial tire sidewall point cloud collected by the 3D sensor;

[0012] S2. Based on the target tire sidewall point cloud, perform tire character segmentation through flat area filtering processing and Euclidean space clustering algorithm;

[0013] S3. Based on the recognition of the character, determine the engraving position, obtain the character point cloud coordinates and the rotation angle of the engraving content, determine the laser engraving coordinates, and generate a drive signal including the laser engraving coordinates.

[0014] In a third aspect, an embodiment of the present application further provides a readable storage medium, which includes a tire sidewall engraving method program. When the tire sidewall engraving method program is executed by a processor, the steps of a tire sidewall engraving method as described in any one of the above are implemented.

[0015] As can be seen from the above, an embodiment of the present application provides a tire sidewall engraving device, method and readable storage medium. The device includes a loading layer, a scanning layer and an engraving layer arranged in sequence from bottom to top, wherein: the tire to be processed is placed at the loading layer; a double-track synchronous gantry slide is provided at the scanning layer, and along the direction facing the tire sidewall on the slide, a plurality of 3D sensors for collecting tire sidewall point clouds are provided; a laser engraving head is provided at the engraving layer. The laser engraving head is used to irradiate the etching laser to the engraving position on the tire sidewall under the drive of a drive signal generated by the controller based on the tire sidewall point cloud. The present application uses a laser to engrave on the side of the already formed tire, which can effectively avoid the occurrence of poor operation caused by manual operation, accurately perform laser engraving on the position that needs to be engraved on the tire sidewall, improve the production quality of the tire, and at the same time greatly improve the engraving efficiency of the tire sidewall, which is beneficial to ensuring the consistency of the product. In addition, for white sidewall tires, the cover rubber on the decorative film can be directly engraved and removed to expose the white sidewall, ensuring that the surface of the white rubber is delicate and smooth.

[0016] Other features and advantages of the present application will be described in the subsequent specification, and, in part, will become apparent from the specification, or can be understood by implementing the embodiments of the present application. The objectives and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the written specification, claims, and drawings. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 Schematic three-dimensional structure diagram of a tire sidewall engraving device provided by an embodiment of the present application;

[0019] Figure 2 Schematic side view structure diagram of a tire sidewall engraving device provided by an embodiment of the present application;

[0020] Figure 3 Schematic flow chart of a tire sidewall engraving method provided by an embodiment of the present application;

[0021] Figure 4 Schematic diagram of the target tire sidewall point cloud segmented based on the region of interest provided by an embodiment of the present application;

[0022] Figure 5 Schematic diagram of the point cloud after plane filtering processing provided by an embodiment of the present application;

[0023] Figure 6 Schematic diagram of the point cloud after performing the clustering algorithm in the Euclidean space provided by an embodiment of the present application;

[0024] Figure 7 Schematic diagram of the fixed number provided by an embodiment of the present application.

[0025] In the drawings, the list of components represented by each reference numeral is as follows:

[0026] 1. Slide table, 2. 3D sensor, 3. Laser engraving head, 4. Electric slide rail, 5. Conveying mechanism, 6. Laser, 7. Three-dimensional galvanometer, 8. Dust collector. Detailed implementation manners

[0027] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Usually, the components of the embodiments of the present application described and shown here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0028] It should be noted that: similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0029] Please refer to Figure 1 , Figure 1 FIG. 1 is a schematic structural diagram of a tire sidewall engraving device in some embodiments of the present application. The device includes a loading layer, a scanning layer, and an engraving layer arranged in sequence from bottom to top, where: the tire to be processed is placed at the loading layer; a double-rail synchronous gantry slide 1 is provided at the scanning layer, and one or more 3D sensors 2 for collecting the point cloud of the tire sidewall are provided on the slide 1 along the direction facing the tire sidewall; a laser engraving head 3 is provided at the engraving layer, and the laser engraving head 3 is used to irradiate the etching laser to the engraving position on the tire sidewall under the drive of a drive signal generated by the controller based on the point cloud of the tire sidewall.

[0030] As can be seen from the above, a tire sidewall engraving device disclosed in the present application includes a loading layer, a scanning layer, and an engraving layer arranged in sequence from bottom to top, where: the tire to be processed is placed at the loading layer; a double-rail synchronous gantry slide 1 is provided at the scanning layer, and one or more 3D sensors 2 for collecting the point cloud of the tire sidewall are provided on the slide 1 along the direction facing the tire sidewall; a laser engraving head 3 is provided at the engraving layer, and the laser engraving head 3 is used to project the etching laser onto the engraving position on the tire sidewall under the drive of a drive signal generated by the controller based on the point cloud of the tire sidewall. The present application uses a laser to engrave on the side of a formed tire, which can effectively avoid the occurrence of poor operation caused by manual operation, accurately perform laser engraving on the position that needs to be engraved on the tire sidewall, improve the quality of tire production, and at the same time greatly improve the engraving efficiency of the tire sidewall, which is beneficial to ensuring the consistency of the product. In addition, for white sidewall tires, the cover rubber on the decorative film can be directly engraved and removed to expose the white sidewall, ensuring that the white rubber surface is delicate and smooth.

[0031] In one embodiment, floor screws are provided on each support foot at the loading layer. By adjusting the height of the floor screws, the loading layer meets the horizontal requirement.

[0032] It should be noted that the loading layer is a conveying mechanism 5 for transporting tires, and floor screws for adjusting its height are provided on each support foot of the conveying mechanism 5, so that the conveying surface of the conveying mechanism 5 is in a horizontal plane state. The height of each floor screw is adjusted by a level gauge to enable the base to have a leveling function, so that the entire loading layer meets the horizontal requirement.

[0033] In one embodiment, support portions are provided between two sides in the width direction of the conveying mechanism 5. An electric slide rail 4 is provided on the upper end surface of the support portion. Two ends of the slide table 1 are respectively drivingly connected to the corresponding electric slide rail 4, and the electric slide rail 4 can drive the slide table 1 to drive the 3D sensor 2 to move bidirectionally along the conveying direction of the conveying mechanism 5.

[0034] In one embodiment, please refer to Figure 2 , a 3D sensor 2 is arranged on the slide table 1 along the direction facing the side wall of the tire. When a plurality of 3D sensors 2 are arranged, an interval is left between two adjacent 3D sensors 2; within a preset upper and lower adjustment range, each 3D sensor 2 has a corresponding adjustment space and has a fine rotation adjustment function around the Z axis.

[0035] It should be noted that a plurality of 3D sensors 2 all have an adjustment range of ±10 mm up and down and have a fine rotation adjustment function around the Z axis to avoid mechanical errors during installation. Here, in this embodiment, four 3D sensors 2 are arranged side by side at intervals, and in practice, it can be flexibly set according to needs.

[0036] In an embodiment of the present invention, the laser engraving head 3 includes a laser 6 and a three-dimensional galvanometer 7. Compared with the traditional two-dimensional galvanometer in cooperation with the movement mode in the Z-axis direction, the three-dimensional galvanometer 7 has the advantages of fast scanning speed and no need for separate adjustment in the Z-axis direction, greatly improving the scanning efficiency.

[0037] In one embodiment, a calibration plate for auxiliary calibration is further provided at the load layer. A plurality of characteristic geometric bodies with known heights are provided on the calibration plate; on one side of the laser engraving head 3, a 2D camera for collecting the calibration plate image corresponding to the calibration plate and transmitting the calibration plate image to a controller electrically connected is provided;

[0038] The 2D camera is used to photograph and scan the characteristic geometric bodies and obtain the characteristic point plane coordinate information corresponding to the characteristic geometric bodies;

[0039] The controller determines a first conversion matrix between the tire sidewall point cloud coordinates and the 2D camera coordinates according to the coordinate information of the tire sidewall point cloud and the characteristic point plane coordinate information corresponding to the characteristic geometric bodies. Here, the characteristic geometric body can be set as a characteristic cylinder, and the characteristic point is the position of the center of the upper surface of the characteristic cylinder.

[0040] In the above embodiment, by setting the calibration plate and combining the use of the 2D camera, the complexity of calibration is reduced, and the calibration efficiency and accuracy are improved.

[0041] In one embodiment, the 3D sensor 2 is further configured to collect calibration plate point clouds and transmit the calibration plate point clouds to the controller. The controller establishes a target transformation matrix from the 3D sensor 2 to the laser engraving head 3 based on the calibration plate point clouds and the calibration plate images, and converts the point cloud coordinates determined based on the tire sidewall point clouds into laser engraving coordinates based on the target transformation matrix, and drives the laser engraving head 3 to engrave along the laser engraving coordinates.

[0042] Specifically, the controller determines a second transformation matrix between the laser engraving coordinates calibrated by the laser engraving head 3 and the 2D camera coordinates according to the calibration information of the laser engraving head 3 and the characteristic point plane coordinate information corresponding to the characteristic geometric body, and determines the target transformation matrix between the laser engraving head 3 and the 3D sensor 2 according to the first transformation matrix and the second transformation matrix.

[0043] In the current embodiment, the positions of the laser engraving head 3 and the 3D sensor 2 are specifically calibrated quickly through two-dimensional vision.

[0044] In one or more embodiments of the present invention, the tire sidewall engraving device further includes a dust collector 8, and the dust removal pipe of the dust collector 8 is used to suck the dust generated when engraving the surface of the tire sidewall. By providing the dust collector 8, the dust, foreign objects, etc. generated when engraving the surface of the tire sidewall can be sucked in real time, ensuring a clean and hygienic processing environment.

[0045] Please refer to Figure 3 , a tire sidewall engraving method applicable to the device described in any one of the above, which is applied to the controller, includes the following steps:

[0046] Step S1, determining a target tire sidewall point cloud according to the initial tire sidewall point cloud collected by the 3D sensor 2.

[0047] It should be noted that in the current embodiment, an area of interest is pre-selected, and the required target tire sidewall point cloud is segmented from the obtained initial tire sidewall point cloud according to the area of interest. For the specific segmentation steps, please refer to the subsequent embodiments and will not be elaborated here. For the display effect of the final target tire sidewall point cloud, please refer to Figure 4 .

[0048] Step S2, performing tire character segmentation based on the target tire sidewall point cloud through flat area filtering processing and Euclidean space clustering algorithm.

[0049] It should be noted that the flat area filtering processing refers to filtering out the point clouds corresponding to the flat areas from the target tire sidewall point clouds and only retaining the character point clouds. For the final effect, please refer to Figure 5The Euclidean space clustering algorithm refers to performing the clustering algorithm in the Euclidean space based on the retained character point cloud, so that each character point cloud can be completely segmented finally. The final segmentation effect can be referred to Figure 6 。

[0050] Step S3: Determine the engraving position based on the recognition of the character, obtain the character point cloud coordinates and the rotation angle of the engraving content, determine the laser engraving coordinates, and generate a driving signal including the laser engraving coordinates.

[0051] It should be noted that for the calculation of the rotation angle of the engraving content, it is necessary to first determine the angle α where the character is located according to the center and radius of the character; then, obtain the relative angle β of the engraved character, and determine the rotation angle of the engraving content β + α according to the angle α where the character is located. Among them, the rotation angle of the engraving content will be further transmitted to the controller so that the controller can adjust the outgoing light angle of the etching laser emitted by the laser engraving head 3 according to the rotation angle of the engraving content.

[0052] In the embodiment of the present invention, under the action of the driving signal, the laser engraving head 3 irradiates the etching laser to the engraving position on the tire sidewall and engraves the surface of the tire sidewall, and a corresponding engraving pattern can be formed. In particular, for white sidewall tires, a white rubber surface with a delicate and smooth surface can be obtained.

[0053] As can be seen from the above, a tire sidewall engraving method disclosed in the present application uses a laser to engrave on the sidewall of a formed tire, which can effectively avoid the occurrence of poor operation caused by manual operation, accurately perform laser engraving on the position of the tire sidewall that needs to be engraved, and improve the tire production quality.

[0054] In one of the embodiments, in step S1, the determining the target tire sidewall point cloud includes:

[0055] Step S11: Obtain the initial tire sidewall point cloud collected by the 3D sensor 2.

[0056] Step S12: Determine the first point set of the initial tire sidewall point cloud, and when it is determined that the target point in the first point set is within the range covered by the preset region of interest, add the target point to the preset second point set.

[0057] Specifically, in the current embodiment, the ranges of x, y, and z of the region of interest will be set as (Xmin, Xmax), (Ymin, Ymax), (Zmin, Zmax). Traverse each point in the first point set, and during the traversal process, judge whether the X, Y, and Z values of the traversed point meet the following conditions:

[0058] Xmin < X < Xmax;

[0059] Ymin < Y < Ymax;

[0060] Zmin < Z < Zmax;

[0061] If it is determined that the above conditions are met, add the traversed point to a preset second point set.

[0062] Step S13, when it is determined that all target points have been added, based on the second point set, determine the target tire sidewall point cloud.

[0063] In the above embodiment, the required target tire sidewall point cloud is segmented from the obtained initial tire sidewall point cloud according to the region of interest, which can greatly reduce the data volume of the point cloud and also reduce the influence of noise, providing a good data basis for subsequent tire character positioning and segmentation.

[0064] In one embodiment, in step S2, based on the target tire sidewall point cloud, through flat area filtering processing and Euclidean space clustering algorithm, character component segmentation is performed, including:

[0065] Step S21, based on the target tire sidewall point cloud, perform point cloud normal estimation.

[0066] It should be noted that in the current embodiment, when performing point cloud normal estimation and extraction, the specific implementation steps are not limited at present.

[0067] Step S22, based on the normal difference between the normal of the character region and the normal of the flat region, filter out the point cloud corresponding to the flat region from the target tire sidewall point cloud to obtain the character point cloud.

[0068] It should be noted that through practical analysis, it can be known that there is a relatively large difference between the normal of the character region and the normal of the flat region. In the current embodiment, based on this analysis result, it is considered to filter out the point cloud corresponding to the flat region from the target tire sidewall point cloud and retain the character point cloud.

[0069] During specific implementation, in this embodiment, a filtering algorithm based on normal difference is executed. The specific algorithm process is as follows:

[0070] First, take any point P in the target tire sidewall point cloud i , select different radii of neighbors r1, r2, and calculate the normal n1, n2 of point P i .

[0071] Then, filter according to the angle θ between the two normals n1, n2 of point P i , that is, identify whether point P i belongs to the plane region and perform filtering.

[0072] Finally, traverse the other points and repeat the above two steps. After the traversal, the corresponding character point cloud is obtained.

[0073] Finally, set r1 = 1.5 and r2 = 2, and the filtered point cloud obtained is as Figure 4 shown.

[0074] Step S23: Based on the character point cloud, perform character component segmentation through the Euclidean space clustering algorithm.

[0075] Specifically, the process of the Euclidean space clustering algorithm includes:

[0076] First, find a point P in the space from the character point cloud i , and find the n points closest to it. Judge the distances of these n points to P i . And put the points p1, p2, p3.... whose distances are less than the threshold r into the set Q.

[0077] Then, find a point p1 in the set Q and repeat the above steps to find the corresponding p 22 , p 23 , p 24 ...., and put them all into the set Q.

[0078] Finally, when no new points can be added to the set Q, the search is completed, and the individual character point clouds obtained by segmentation are obtained.

[0079] In one embodiment, in step S3, the engraving position is determined through the following steps:

[0080] Step S31: Identify the area where the character is located from each of the segmented character point clouds.

[0081] Specifically, the size and the number of points can be set as the identification conditions to identify the area where the character is located from each character point cloud.

[0082] Step S32: Search and locate the engraved character around the area where the character is located. Among them, there are multiple fixed numbers with a fixed length between the character and the engraved character.

[0083] Specifically, the fixed numbers can refer to Figure 7 the factory number, specifications, patterns, and brand merchants shown in. It should be noted that the position of the cycle number shown in the figure is the engraving position. These fixed numbers all have a fixed length.

[0084] Step S33: Calculate the engraving position of the engraved character based on the total fixed length of each of the fixed numbers when the center and radius of the known character are known.

[0085] In one embodiment, in step S33, the center and radius of the character are determined through the following steps:

[0086] Step S331: Based on the target tire sidewall point cloud, perform z-value dimensionality reduction processing to obtain the dimensionality-reduced planar point cloud, where the planar point cloud has corresponding two-dimensional position information in a pre-established planar rectangular coordinate system.

[0087] Step S332: Fit the dimensionality-reduced planar point cloud to obtain a corresponding point cloud curve.

[0088] Step S333: Based on the two-dimensional position information corresponding to the point cloud curve, determine the tire radius and the tire center.

[0089] Step S334: Update the z-value of the tire center based on the average z-value of the character, and use the tire radius and the updated tire center as the center and radius where the character is located.

[0090] The embodiment of the present application provides a storage medium. When the computer program is executed by a processor, it executes the method in any optional implementation manner of the above embodiment. Among them, the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (abbreviated as SRAM), electrically erasable programmable read-only memory (abbreviated as EEPROM), erasable programmable read-only memory (abbreviated as EPROM), programmable read-only memory (abbreviated as PROM), read-only memory (abbreviated as ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0091] The above-readable storage medium uses a laser to engrave on the side of the already formed tire, which can effectively avoid the occurrence of poor operation caused by manual operation, accurately perform laser engraving on the position that needs to be engraved on the tire sidewall, and improve the tire production quality.

[0092] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some communication interfaces. The indirect coupling or communication connection of the devices or units can be in electrical, mechanical or other forms.

[0093] In addition, the units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0094] Furthermore, in each embodiment of the present application, the functional modules can be integrated together to form an independent part, or each module can exist alone, or two or more modules can be integrated to form an independent part.

[0095] In this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0096] The above are only the embodiments of the present application and are not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for engraving on a tire sidewall, which is applicable to a tire sidewall engraving device, characterized in that, The device comprises a carrier layer, a scanning layer and an engraving layer arranged in sequence from bottom to top, wherein: The tire to be processed is placed on the loading layer; A double-track synchronous gantry slide (1) is provided at the scanning layer, and one or more 3D sensors (2) for collecting a point cloud of the tire sidewall are provided on the slide (1) along a direction facing the tire sidewall; A laser engraving head (3) is provided at the engraving layer, and the laser engraving head (3) is used to irradiate an etching laser to an engraving position on the tire sidewall and engrave the tire sidewall surface under the drive of a driving signal generated by a controller based on the tire sidewall point cloud; The method is applied to a controller and comprises the following steps: S1, determining a target tire sidewall point cloud according to an initial tire sidewall point cloud acquired by the 3D sensor (2); S2. Based on the target tire sidewall point cloud, tire character segmentation is performed through flat area filtering and Euclidean space clustering algorithm; S3, determining the engraving position based on character recognition, obtaining the character point cloud coordinates and the rotation angle of the engraving content, determining the laser engraving coordinates, and generating a driving signal including the laser engraving coordinates; Wherein, in step S2, character component segmentation is performed based on the target tire sidewall point cloud by flat area filtering and Euclidean space clustering algorithm, including: S21, estimating a point cloud normal based on the target tire sidewall point cloud; S22, based on the normal difference between the normal of the character area and the normal of the flat area, filtering out the point cloud corresponding to the flat area from the target tire sidewall point cloud to obtain the character point cloud; S23. Based on the character point cloud, character component segmentation is performed using a Euclidean space clustering algorithm.

2. The method according to claim 1, wherein The load layer is a conveying mechanism (5) for transporting tires, a support portion is provided between two sides of the conveying mechanism (5) in a width direction, an electric slide rail (4) is provided on the upper end surface of the support portion, two ends of the slide table (1) are respectively connected to the corresponding electric slide rails (4) in a transmission manner, and the electric slide rails (4) can drive the slide table (1) to drive the 3D sensor (2) to move in two directions along the conveying direction of the conveying mechanism (5); A 3D sensor (2) is arranged on the slide (1) in a direction facing the tire sidewall, and when a plurality of 3D sensors (2) are arranged, a gap is left between two adjacent 3D sensors (2), and the posture of the 3D sensor (2) in three-dimensional space is adjustable.

3. The method according to claim 1, wherein The carrier layer is also provided with a calibration plate for auxiliary calibration, and the calibration plate is provided with a plurality of characteristic geometric bodies with known heights; A 2D camera is provided on one side of the laser engraving head (3) for collecting a calibration plate image corresponding to the calibration plate and transmitting the calibration plate image to a controller, and the 2D camera is electrically connected to the controller; The 2D camera is used to take a picture and scan the characteristic geometric body, and obtain the plane coordinate information of the characteristic points corresponding to the characteristic geometric body; The controller determines a first transformation matrix between the coordinates of the tire sidewall point cloud and the feature point plane coordinates corresponding to the feature geometric body according to the coordinate information of the tire sidewall point cloud and the feature point plane coordinates corresponding to the feature geometric body.

4. The method according to claim 3, wherein The controller determines a second transformation matrix between the calibrated engraving coordinates of the laser engraving head (3) and the 2D camera coordinates according to the calibration information of the laser engraving head (3) and the feature point plane coordinates corresponding to the feature geometric body, and determines a target transformation matrix between the laser engraving head (3) and the 3D sensor (2) according to the first transformation matrix and the second transformation matrix; Based on the target transformation relationship, the point cloud coordinates determined based on the tire sidewall point cloud are converted into laser engraving coordinates, and the laser engraving head (3) is driven to engrave along the laser engraving coordinates.

5. The method according to any one of claims 1-4, characterized in that, It further includes a dust collector (8), and the dust removal pipe of the dust collector (8) is used to suck the dust generated during the engraving of the tire sidewall surface.

6. The method according to claim 1, characterized in that, In step S1, the determination of the target tire sidewall point cloud includes: S11. Obtain the initial tire sidewall point cloud collected by the 3D sensor (2); S12. Determine a first point set of the initial tire sidewall point cloud, and when it is determined that the target point in the first point set is within the range covered by the preset region of interest, add the target point to the preset second point set; S13. When it is determined that all target points have been added, determine the target tire sidewall point cloud based on the second point set.

7. The method according to claim 1, characterized in that, In step S3, the engraving position is determined through the following steps: S31. Identify the area where the character is located from each of the segmented character point clouds; S32. Search and locate the engraved character around the area where the character is located, where there are multiple fixed numbers with a fixed length between the character and the engraved character; S33. Calculate the engraving position where the engraved character is located according to the total fixed length of each of the fixed numbers and the center and radius of the circle where the character is located.

8. The method according to claim 7, wherein In step S33, the center and radius of the circle where the character is located are determined through the following steps: S331. Perform a z-value dimensionality reduction process on the target tire sidewall point cloud to obtain the dimensionality-reduced plane point cloud, where the plane point cloud has corresponding two-dimensional position information in a pre-established plane rectangular coordinate system; S332. Fit the dimensionality-reduced plane point cloud to obtain a corresponding point cloud curve; S333. Determine the tire radius and the tire center based on the two-dimensional position information corresponding to the point cloud curve; S335. Update the z-value of the tire center based on the average z-value of the character, and use the tire radius and the updated tire center as the center and radius of the circle where the character is located.

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