A composite coating that is beneficial to laser radar sensor acquisition and identification, and its preparation method and application

Abstract

The present invention discloses a composite coating that is conducive to the acquisition and identification of laser radar sensors, as well as its preparation method and application. The composite coating includes a base coating and a transparent or translucent easy-to-identify layer sprayed thereon; the base coating is obtained by spraying with a metal primer; the easy-to-identify layer is obtained by spraying with an easy-to-identify functional composition, and the easy-to-identify functional composition includes the following raw materials in parts by weight: 15 to 60 parts of acrylic resin; 5 to 20 parts of amino resin; 0 to 5 parts of silane coupling agent; 15 to 45 parts of high-refractive index microbeads; 1 to 10 parts of auxiliary agent; and 2 to 20 parts of solvent. The composite coating provided by the present invention can be directly sprayed on the surface of a metal substrate or a non-metallic substrate, which can reduce the angular sensitivity of the metal substrate or metal primer to the laser radar signal, ensure the stability of the composite coating's reflection intensity to the laser radar signal, and improve the composite coating's reflection intensity to the laser radar signal.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings and more particularly to a composite coating that facilitates acquisition and recognition by a laser radar sensor, and a preparation method and application thereof. Background Art

[0002] Modern technology has evolved through mechanization, electrification, informatization, and today's intelligentization. Intelligent robots have been applied in various fields in recent years, and advanced robots with higher intelligent perception capabilities and the ability to perform complex tasks have become a research and development hotspot. It is conceivable that highly intelligent robots will appear in various fields in the future, such as infrastructure construction and maintenance, high-end manufacturing, and even the service industry. For example, the rapid development of self-driving cars in recent years is also a form of intelligent robot, or smart car, in a broad sense. Smart cars utilize advanced perception technology and the effective cooperation of computer analysis systems, decision-making systems, and control systems to automatically perform maneuvers such as cruising, merging, avoiding, and overtaking.

[0003] Because robots are feedback-based closed-loop control systems, ignoring their scenario-specific application design, their core technologies and components can be summarized into four parts: the main structure, the perception device system, the decision-making and planning scheduling system, and the control execution system. The perception device system can be thought of as the robot's "eyes." These sensors help the robot perceive environmental information and make appropriate decisions. For example, a sweeping robot needs to move from point A to point B to complete its cleaning task. Route planning requires understanding surrounding obstacles to avoid them. Similarly, a robot in a hotel lobby needs to identify signposts on the ground to find its route.

[0004] LiDAR technology, a sensor technology with advantages such as long-range recognition, high resolution, and immunity to ambient light, is currently widely used in smart cars equipped with advanced autonomous or assisted driving systems. As one of the primary sensing devices, it helps smart cars identify their surroundings through integrated sensing solutions. This approach has become a mainstream approach adopted by many OEMs. Similar smart robots, such as delivery robots in hospitals and hotels, and smart sweeping robots for home use, are also equipped with corresponding models of LiDAR sensors to scan and map routes and identify obstacles.

[0005] LiDAR scanning utilizes a laser to emit a specific wavelength and a receiver to receive the reflected signal from an object's surface, generating raw data. The mainstream Time of Flight (TOF) mode measures the distance between an object and the signal source based on the time it takes for the return signal to arrive. High-frequency, multi-line scanning LiDAR can generate high-resolution point clouds in three-dimensional space.

[0006] While LiDAR devices utilize different technologies, under the same equipment and environmental conditions, the signal strength received by the LiDAR is directly related to the reflectivity of the laser light source from the object being measured. In other words, the reflective characteristics of an object's surface directly affect the LiDAR's detection range and accuracy, significantly varying detectability and, in turn, the overall perception process.

[0007] Materials or coatings with metallic surface effects and textures are widely used in various decorative coating applications due to their unique appearance, such as automotive bodies, electronic device casings, and household appliance bodies. This metallic or simulated metal appearance and texture has long been a favorite among consumers and holds significant market value. Common methods for creating surface coatings with a metallic appearance and texture are metal plating, electroplating, or spraying metallic paint. Metallic paints are primarily created by adding flake aluminum powder, copper powder, or other similar metallic-luster effect pigments, such as pearlescent mica, to the paint formula. These metallic flakes, due to their high gloss, produce a strong specular reflection of incident light, similar to the metal substrate. Furthermore, metallic paints and metal substrates also produce strong specular reflection of non-visible light sources, such as LiDAR signals, resulting in near-total reflection of vertically incident LiDAR signals. Therefore, high-gloss metal substrates or coatings with metallic surface effects and textures are highly detectable by LiDAR sensors at a certain distance and perpendicular to the sensor's direction of incidence.

[0008] However, in various driving scenarios, such as autonomous driving, there are limited opportunities for LiDAR signals to strike surfaces perpendicularly. First, the shapes of cars and other vehicles are irregular and non-planar. Most surfaces detected by LiDAR are also irregular and non-planar. Second, as detection range increases, the spacing between LiDAR beams increases, reducing the number of effective beams. Edges are not received by the receiver due to specular reflection. Therefore, for high-gloss metal surfaces or coated surfaces with a metallic texture and appearance, the return signal strength and quantity decrease significantly for detector signals incident at an angle to the surface normal. This is known as high angle sensitivity, which is highly detrimental to effective detection in various driving scenarios. For LiDAR, this results in increased fluctuation in received data pixels due to angle variations, reducing effectiveness and making data reliability unpredictable. This hinders the judgment and decision-making process of the decision-making system, and can easily lead to detection failures, thus compromising safety.

[0009] In view of this, it is necessary to provide an easily identifiable coating that has good stability under detection at different angles and can be directly used to improve the surface of a coating with a metallic appearance and texture, so that it still has a high and stable reflection intensity for laser radar detection signals with gradually increasing incident angles. Summary of the Invention

[0010] To address these issues, the first objective of the present invention is to provide a composite coating that facilitates LiDAR sensor acquisition and recognition. Directly spraying the composite coating onto a substrate significantly enhances the composite coating's reflection intensity for LiDAR signals and reduces the adverse effects of the high angular sensitivity of the metal substrate and the metallic primer within the composite coating, thereby providing enhanced recognition redundancy and safety for various driving scenarios, including autonomous driving.

[0011] The second object of the present invention is to provide a method for preparing the composite coating as described above.

[0012] The third object of the present invention is to provide an application of the composite coating.

[0013] In order to achieve the above first object, the present invention adopts the following technical solutions:

[0014] The present invention discloses a composite coating that is beneficial to the acquisition and identification of a laser radar sensor, comprising a base coating and a transparent or translucent easy-to-identify layer sprayed thereon;

[0015] The base coating is obtained by spraying with a metal primer;

[0016] The easy-to-identify layer is obtained by spraying an easy-to-identify functional composition, and the easy-to-identify functional composition includes the following raw materials in parts by weight:

[0017] 15-60 parts of acrylic resin;

[0018] 5-20 parts of amino resin;

[0019] Silane coupling agent 0-5 parts;

[0020] 15-45 parts of high refractive index microbeads;

[0021] 1 to 10 parts of additives;

[0022] 2 to 20 parts of solvent.

[0023] Furthermore, the high refractive index microbeads account for 15 to 45 wt % of the total weight of the easy-to-identify functional composition.

[0024] Furthermore, the refractive index of the high-refractive-index microbeads in the near-infrared spectrum region is not less than 1.75.

[0025] Furthermore, the refractive index of the high-refractive-index microbeads in the near-infrared spectrum region is not less than 1.9.

[0026] Furthermore, the refractive index of the high-refractive-index microbeads in the near-infrared spectrum region is between 1.9 and 2.7.

[0027] Furthermore, the particle size of the high refractive index microbeads is 0.01 to 350 μm.

[0028] Furthermore, the particle size of the high refractive index microbeads is 0.1 to 50 μm.

[0029] Furthermore, the high refractive index microspheres are selected from one or a combination of high refractive index glass microspheres, high refractive index optically transparent ceramic microspheres, and high refractive index amorphous polymer microspheres.

[0030] Furthermore, the high refractive index microbeads are selected from CX-1000 high refractive index glass microbeads produced by Weicaixiang Technology Co., Ltd.

[0031] Furthermore, the acrylic resin is selected from EMA-1032 and / or EMA-1015 of Nippon Paint Co., Ltd.; the amino resin is selected from CYMEL250 and / or CYMEL370N of Cytec Chemical;

[0032] The silane coupling agent is selected from one or a combination of KH-550, KH-560, KH-570, KH-580, KH-590, KH-902, KH-792, and KH-903 produced by Dow Corning;

[0033] The auxiliary agent includes one or a combination of antioxidants, light aging agents and leveling dispersants.

[0034] Furthermore, the antioxidant is selected from BASF's B215; the light aging agent is selected from Rianlon's UV944; and the leveling dispersant is selected from BYK-345, BYK-187, BYK-192, or a combination thereof.

[0035] Furthermore, the metal primer is selected from Nippon Paint's AR3500(T) silver primer.

[0036] In order to achieve the above second purpose, the present invention adopts the following technical solutions:

[0037] The present invention discloses a method for preparing the composite coating as described above, comprising the following steps:

[0038] Spraying metal primer on the surface of the substrate to obtain a base coat after surface drying;

[0039] Continue spraying the easy-identification functional composition on the base coating layer, and obtain an easy-identification layer after the surface is dried;

[0040] The coating is dried naturally or baked at room temperature to completely dry the primer layer and the easily identifiable layer to obtain a composite coating.

[0041] Furthermore, the substrate is selected from a metal substrate or a non-metal substrate;

[0042] The metal substrate is selected from tinplate or stainless steel; the non-metallic substrate is selected from PP plastic board.

[0043] In order to achieve the third object, the present invention adopts the following technical solutions:

[0044] The present invention discloses an application of the composite coating described above in the coating of intelligent vehicles and intelligent robots.

[0045] The beneficial effects of the present invention are as follows:

[0046] The present invention provides a composite coating that is conducive to the collection and identification of laser radar sensors. By spraying an easily identifiable functional composition containing high-refractive index microbeads on a metal primer, not only the reflection intensity of the laser radar signal is improved, but also the adverse effects of the strong angle sensitivity of the metal substrate and the metal primer in the composite coating are reduced, so that the reflectivity signal stability of the laser signal at different incident angles is significantly enhanced, and the fluctuation range of the reflectivity signal is reduced. Accordingly, the laser radar sensor can more easily collect more data pixel points returned on the surface involved, thereby obtaining richer obstacle information, to ensure that autonomous driving or smart devices can recognize identification and successfully avoid obstacles.

[0047] The composite coating provided by the present invention also exhibits excellent mechanical properties, durability, aging resistance, and corrosion resistance. Furthermore, the composite coating provided by the present invention is transparent or translucent, minimally impacting the metal's appearance and resulting in a superior appearance. Therefore, it can be used as a surface coating for various devices in numerous scenarios, such as those associated with smart cars or intelligent robotic systems, providing both decorative and protective effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0049] Figure 1 A schematic diagram showing the structures of different test samples in the laser radar reflectivity test of the present invention.

[0050] Figure 2 A schematic diagram showing the fixing of a test sample on a sample test stand in the laser radar reflectivity test of the present invention.

[0051] Figure 3A schematic diagram showing a method for testing the reflection intensity of a laser radar signal in a laser radar reflectivity test according to the present invention. DETAILED DESCRIPTION

[0052] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the following detailed description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0053] Unless otherwise specified, parts and numbers refer to parts by weight. Unless otherwise specified, the experimental materials and reagents used in the following examples can be obtained from commercial sources.

[0054] Angular sensitivity, as used in this disclosure, refers to the degree of fluctuation in the reflection intensity of a substrate or coating in response to LiDAR signals at different angles of incidence. Large fluctuations in the reflection intensity of LiDAR signals at different angles of incidence indicate strong angular sensitivity of the substrate or coating to the LiDAR signal; conversely, weak angular sensitivity. The specular reflection effect of metal substrates and coatings with a metallic appearance and texture can lead to strong angular sensitivity, which can severely hinder LiDAR sensor acquisition and recognition in practical applications.

[0055] To address the angular sensitivity issues of metal substrates and coatings with metallic texture and appearance, the present invention provides a composite coating that facilitates acquisition and recognition by a laser radar sensor. The composite coating comprises a base coating and a transparent or translucent easily identifiable layer sprayed thereon.

[0056] The base coating is obtained by spraying with a metal primer;

[0057] The easy-to-identify layer is obtained by spraying an easy-to-identify functional composition, and the easy-to-identify functional composition includes the following raw materials in parts by weight:

[0058] 15-60 parts of acrylic resin;

[0059] 5-20 parts of amino resin;

[0060] Silane coupling agent 0-5 parts;

[0061] 15-45 parts of high refractive index microbeads;

[0062] 1 to 10 parts of additives;

[0063] 2 to 20 parts of solvent.

[0064] Research has found that the composite coating of the present invention, through the combined action of the metal primer and the high-refractive-index microbeads in the easy-to-identify functional composition, enhances the reflection intensity of the composite coating to LiDAR signals, particularly for non-metallic substrates such as PP plastic, enabling more effective return signals. Furthermore, to mitigate the adverse effects of the high angular sensitivity of the metal substrate and the metal primer in the composite coating, ensuring stable reflectivity of laser signals at varying angles of incidence, researchers unexpectedly discovered that spraying the easy-to-identify functional composition directly onto the metal primer can address this issue. Compared to the prior art multi-layer design, where a midcoat and topcoat are applied to the metal substrate or metal primer to minimize the angular sensitivity of the metal substrate or metal primer, the composite coating of the present invention reduces the development cost, time, and raw material costs of intermediate layers such as the midcoat and topcoat, shortens the coating spraying process, and eliminates the need to consider interlayer adhesion, interlayer compatibility, and hiding properties associated with these intermediate layers. This provides a new direction for the development of coatings recognizable by LiDAR sensors.

[0065] Furthermore, the high refractive index microbeads account for 15 to 45 wt % of the total weight of the easy-to-identify functional composition.

[0066] Furthermore, the refractive index of the high-refractive-index microbeads provided by the present invention in the near-infrared spectral region (800-2500 nm) is not less than 1.75. Preferably, the refractive index of the high-refractive-index microbeads provided by the present invention in the near-infrared spectral region is not less than 1.9. More preferably, the refractive index of the high-refractive-index microbeads provided by the present invention in the near-infrared spectral region is between 1.9 and 2.7.

[0067] Furthermore, the particle size of the high refractive index microbeads provided by the present invention is 0.01 to 350 μm. Preferably, the particle size of the high refractive index microbeads provided by the present invention is 0.1 to 50 μm.

[0068] Furthermore, the high refractive index microspheres are selected from one or a combination of high refractive index glass microspheres, high refractive index optically transparent ceramic microspheres, and high refractive index amorphous polymer microspheres.

[0069] In one embodiment, the high refractive index microspheres are selected from CX-1000 high refractive index glass microspheres manufactured by Weicaixiang Technology Co., Ltd. The high refractive index optically transparent ceramic microspheres and high refractive index amorphous polymer microspheres can be prepared using methods disclosed in the prior art.

[0070] Furthermore, the easy identification functional composition comprises 40-50 parts of an acrylic resin; the acrylic resin is selected from EMA-1032 and / or EMA-1015 produced by Nippon Paint Co., Ltd. In one embodiment, the easy identification functional composition comprises 10-35 parts of EMA-1032 and 5-25 parts of EMA-1015. Preferably, the easy identification functional composition comprises 20-35 parts of EMA-1032 and 10-25 parts of EMA-1015.

[0071] Furthermore, the easy-identification functional composition comprises 10-20 parts of an amino resin; the amino resin is selected from CYMEL250 and / or CYMEL370N produced by Cytec Chemical. In one embodiment, the easy-identification functional composition comprises 3-15 parts of CYMEL250 and 2-10 parts of CYMEL370N. Preferably, the easy-identification functional composition comprises 5-15 parts of CYMEL250 and 5-10 parts of CYMEL370N.

[0072] Furthermore, the silane coupling agent is a silane coupling agent containing a siloxy group, and its structure is usually represented by R-SiX3, specifically, X represents a methoxy group or an ethoxy group, and R represents a functional group such as a mercapto group, a polysulfide group, an amino group, a modified amino group, a vinyl group, an epoxy group, a cyano group, an isocyanate group, a methylvinyloxy group, etc., and is selected from one or a combination of KH-550, KH-560, KH-570, KH-580, KH-590, KH-902, KH-792, and KH-903 of Dow Corning. In a specific embodiment, the easy-to-identify functional composition contains 2 to 5 parts of a silane coupling agent.

[0073] Furthermore, the additives include one or a combination of an antioxidant, a light aging agent, and a leveling dispersant. For example, the antioxidant is selected from BASF's B215; the light aging agent is selected from Rianlon's UV944; and the leveling dispersant is selected from BYK-345, BYK-187, and BYK-192, or a combination thereof. In one embodiment, the additives include 1 to 5 parts of an antioxidant, 1 to 5 parts of a light aging agent, and 1 to 5 parts of a leveling dispersant. Those skilled in the art will appreciate that the additives can be selected based on actual process requirements, and the scope of additives that can be used in the present invention is not limited to the additives listed above.

[0074] The use of solvent is to better disperse the raw materials of the easily identifiable functional composition, and technicians can adjust it according to the actual raw material formula. In a specific embodiment, the solvent is selected from isooctyl alcohol and deionized water.

[0075] Furthermore, the metallic primer described in the present invention must contain a certain amount of metallic effect pigments, such as aluminum powder, copper powder, or nickel powder. These metallic components are needed to further reflect the laser light that penetrates the easily identifiable layer. Depending on the application requirements, technicians can add special effect pigments such as pearlescent mica and glass powder, or infrared-absorbing pigments, fillers, resins, and other additives to the metallic primer. For example, carbon black, graphene, carbon nanotubes, and other carbon material-based pigments, cobalt blue, cobalt green, and iron oxide-based black pigments, are also added. Furthermore, when spraying onto a metal substrate, the metallic primer used in the present invention has strong hiding power, preventing the laser light from penetrating the metallic primer. In one embodiment, the metallic primer is selected from Nippon Paint's AR3500(T) silver primer, although other colored primers are also applicable.

[0076] The present invention also provides a method for preparing the composite coating as described above, comprising the following steps:

[0077] Spraying metal primer on the surface of the substrate to obtain a base coat after surface drying;

[0078] Continue spraying the easy-identification functional composition on the base coating layer, and obtain an easy-identification layer after the surface is dried;

[0079] The coating is dried naturally or baked at room temperature to completely dry the primer layer and the easily identifiable layer to obtain a composite coating.

[0080] Furthermore, the easy-to-identify functional composition is prepared according to the following steps:

[0081] Add the formulated amount of acrylic resin, amino resin and additives into the premix container, mix well, then add high refractive index microbeads and disperse at high speed for 10 to 15 minutes;

[0082] Continue to add silane coupling agent and disperse at high speed for 5 to 10 minutes, add solvent and disperse at high speed for 5 to 10 minutes until uniform.

[0083] Furthermore, the rotation speed of the high-speed dispersion is 1000-1500 r / min.

[0084] Furthermore, the substrate is selected from a metal substrate or a non-metal substrate; the metal substrate is selected from tinplate or stainless steel; and the non-metal substrate is selected from PP plastic board.

[0085] Furthermore, the baking condition is baking at 140-160° C. for 30-60 minutes.

[0086] Furthermore, the dry film thickness of the primer layer is 14 to 16 μm, and the dry film thickness of the easily identifiable layer is 43 to 47 μm.

[0087] The specific embodiments of the present invention are described in detail below.

[0088] Example 1

[0089] This embodiment provides a formula of an easily identifiable functional composition, see Table 1.

[0090] Table 1 Easy-to-identify functional composition formula

[0091]

[0092]

[0093] This embodiment also provides a method for preparing a composite coating, comprising the following steps:

[0094] Adding the formulated amount of acrylic resin, amino resin, antioxidant, light aging agent and leveling dispersant into a premixing container, mixing well, adding high refractive index microbeads, and dispersing at a high speed of 1000-1500 r / min for 10-15 minutes; continuously adding a silane coupling agent, and dispersing at a high speed of 1000-1500 r / min for 5-10 minutes; adding a solvent, and dispersing at a high speed of 1000-1500 r / min for 5-10 minutes until uniform, to obtain an easily identifiable functional composition;

[0095] Spray Nippon Paint's AR3500(T) silver primer on the tinplate surface and let it dry to obtain a base coat.

[0096] Continue spraying the easy-identification functional composition on the base coating layer, and obtain an easy-identification layer after the surface is dried;

[0097] The base coat and the easy-to-identify layer were baked at 140° C. for 40 minutes to completely dry the base coat and the easy-to-identify layer, thereby obtaining a test sample. The base coat had a dry film thickness of approximately 15 μm, and the easy-to-identify layer had a dry film thickness of approximately 45 μm.

[0098] Example 2

[0099] This embodiment provides a formula of an easily identifiable functional composition, see Table 2.

[0100] Table 2 Easy-to-identify functional composition formula

[0101]

[0102] The preparation method of the composite coating according to Example 1 includes the following steps:

[0103] preparing an easily identifiable functional composition;

[0104] Spray Nippon Paint's AR3500(T) silver primer on the tinplate surface and let it dry to obtain a base coat.

[0105] Continue spraying the easy-identification functional composition on the base coating layer, and obtain an easy-identification layer after the surface is dried;

[0106] The base coat and the easy-to-identify layer were baked at 140° C. for 40 minutes to completely dry the base coat and the easy-to-identify layer, thereby obtaining a test sample. The base coat had a dry film thickness of approximately 15 μm, and the easy-to-identify layer had a dry film thickness of approximately 45 μm.

[0107] Example 3

[0108] The formula of the easily identifiable functional composition used in this embodiment is the same as that in Example 1, and the only difference from Example 1 is the material of the sprayed substrate.

[0109] The preparation method of the composite coating according to Example 1 includes the following steps:

[0110] preparing an easily identifiable functional composition;

[0111] Spray Nippon Paint's AR3500(T) silver primer on the surface of the PP plastic plate and allow it to dry to form a base coat.

[0112] Continue spraying the easy-identification functional composition on the base coating layer, and obtain an easy-identification layer after the surface is dried;

[0113] The base coat and the easy-to-identify layer were baked at 140° C. for 40 minutes to completely dry the base coat and the easy-to-identify layer, thereby obtaining a test sample. The base coat had a dry film thickness of approximately 15 μm, and the easy-to-identify layer had a dry film thickness of approximately 45 μm.

[0114] Example 4

[0115] The formula of the easily identifiable functional composition used in this embodiment is the same as that in Example 2, and the only difference from Example 2 is the material of the sprayed substrate.

[0116] The preparation method of the composite coating according to Example 2 includes the following steps:

[0117] preparing an easily identifiable functional composition;

[0118] Spray Nippon Paint's AR3500(T) silver primer on the surface of the PP plastic plate and allow it to dry to form a base coat.

[0119] Continue spraying the easy-identification functional composition on the base coating layer, and obtain an easy-identification layer after the surface is dried;

[0120] The base coat and the easy-to-identify layer were baked at 140° C. for 40 minutes to completely dry the base coat and the easy-to-identify layer, thereby obtaining a test sample. The base coat had a dry film thickness of approximately 15 μm, and the easy-to-identify layer had a dry film thickness of approximately 45 μm.

[0121] Comparative Examples 1-6

[0122] This comparative example provides a test sample preparation scheme that was experimented during the research process. The formula of the easily identifiable functional composition and the substrate type are shown in Table 3. The preparation method of the composite coating is similar to that of Example 1, except that the primer is not sprayed on the substrate surface or a conventional primer is used instead of Nippon Paint's AR3500(T) silver primer.

[0123] Table 3 Easy-to-identify functional composition formula and substrate type

[0124]

[0125]

[0126] Note: The conventional primer coating is obtained by spraying Nippon Paint's FLEX700 gray primer on the substrate surface. The FLEX700 gray primer does not contain any metal components and has a dry film thickness of 15μm.

[0127] Performance Test 1: LiDAR Reflectivity Test

[0128] The test samples prepared in Examples 1-4 and Comparative Examples 1-6 were cured for 24 to 48 hours after drying, and then the lidar signal reflection intensity test was performed. Velodyne 32-line lidar (905 nm) and NeuvitionTitan M1 lidar (1550 nm) were used to measure the reflection signal intensity at different distances and different incident angles, with the numerical value ranging from 0 to 255.

[0129] See Figure 1-Figure 3 ,in Figure 1 Schematic diagrams of the structures of different test samples are shown. It should be noted that when there is no primer layer, the structure of the test sample can be understood as a single-coating structure of substrate + easy-to-identify layer. When containing a primer layer, the structure of the test sample can be understood as a double-coating structure of substrate + metal primer / non-metal primer + easy-to-identify layer. Figure 2 This is a schematic diagram of the test sample being fixed on the sample test stand. Figure 3 The present invention shows a reflection intensity test method using a sample test stand and a laser radar device to simulate the change of the incident angle.

[0130] The specific test methods are as follows:

[0131] (1) A sample test stand and a test sample are set at a fixed distance and height, the test sample is placed on the sample test stand, and the sample test stand can be rotated around a fixed axis to change the incident angle of the laser;

[0132] (2) Setting up a laser radar bracket and a laser radar, wherein the laser radar is in the direction of the normal line of the plane where the sample test frame and the test sample are located, and is consistent with the level and height thereof;

[0133] (3) Turn on the Velodyne 32-line (signal source 905nm laser) laser radar and the PC device connected to it, run the supporting software VeloView test software to read the signal intensity value of the test sample surface returned on the laser radar scanning data point cloud map, and take the average of the data point intensity of the entire board surface to obtain the reflected signal intensity;

[0134] (4) Rotate the sample holder around a fixed axis to gradually change the incident angle of the lidar signal and record the reflected signal intensity at different incident angles;

[0135] (5) Replace the laser radar with a different signal source and repeat steps (3) and (4) using the Titan M1 (signal source 1550nm laser) laser radar. Test and record data in the same way. The results are shown in Table 4.

[0136] Table 4 Summary of LiDAR reflectivity test data

[0137]

[0138]

[0139] Result description:

[0140] The reflection intensity of Comparative Examples 1 and 4, which contain neither high-refractive-index microbeads nor primer, is weak, and the reflection intensity of PP plastic plates is weaker than that of tinplate; the reflection intensity of Comparative Examples 2 and 5 after the addition of high-refractive-index microbeads is significantly improved, showing the role of high-refractive-index microbeads in enhancing the reflection intensity; and the reflection intensity of Comparative Examples 3 and 6 after the addition of conventional primer is further improved, but Comparative Examples 1-6 still have the problem of strong angle sensitivity, and the reflection intensity at different incident angles fluctuates greatly. At the test distances of 3m and 7m, the maximum reduction in reflection intensity can reach more than 80%, which will seriously affect the acquisition and recognition of the lidar sensor.

[0141] In contrast, the test panels prepared in Examples 1-4 of the present invention exhibited significantly better test performance than the comparative examples. For example, the aluminum flake structure contained in the AR3500(T) silver primer further reflected the laser light that penetrated the easily identifiable layer, further increasing the reflection intensity compared to the comparative example. This demonstrates the synergistic enhancement effect of the high-refractive-index microspheres and the metallic primer. When the amount of glass microspheres added was moderately increased, the reflection intensity increased. Furthermore, the fluctuation in reflection intensity at different incident angles was significantly reduced. At test distances of 3m and 7m, the maximum drop in reflection intensity was no more than 27%, demonstrating that the composite coating of the present invention is beneficial for LiDAR sensor acquisition and recognition.

[0142] In addition, due to the strong hiding power of metal primer, the reflection intensity is the same regardless of whether the substrate is metal (such as tinplate or stainless steel) or non-metallic substrate (such as PP plastic board). This is because the laser cannot penetrate the metal primer, and the material of the substrate will not affect the reflection performance.

[0143] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A composite coating that facilitates the acquisition and recognition of laser radar sensors, characterized in that: It includes a base coat and a transparent or translucent easily identifiable layer sprayed thereon; The base coating is obtained by spraying with a metal primer; The easy-to-identify layer is obtained by spraying an easy-to-identify functional composition, and the easy-to-identify functional composition includes the following raw materials in parts by weight: 15-60 parts of acrylic resin; 5-20 parts of amino resin; Silane coupling agent 0~5 parts; 15~45 parts of high refractive index microbeads; 1~10 parts of additives; 2-20 parts of solvent; The high-refractive-index microbeads have a refractive index in the near-infrared spectrum region of 1.9 to 2.

7.

2. The composite coating according to claim 1, characterized in that The high refractive index microbeads account for 15 to 45 wt % of the total weight of the easy-to-identify functional composition.

3. The composite coating according to claim 1, characterized in that The particle size of the high refractive index microbeads is 0.01-350 μm.

4. The composite coating according to claim 1, characterized in that The particle size of the high refractive index microbeads is 0.1-50 μm.

5. The composite coating according to claim 1, characterized in that The high-refractive-index microspheres are selected from one or a combination of high-refractive-index glass microspheres, high-refractive-index optically transparent ceramic microspheres, and high-refractive-index amorphous polymer microspheres.

6. The composite coating according to claim 1, characterized in that The high refractive index microbeads are selected from CX-1000 high refractive index glass microbeads produced by Weicaixiang Technology Co., Ltd.

7. The composite coating according to claim 1, characterized in that The acrylic resin is selected from EMA-1032 and / or EMA-1015 of Nippon Paint Co., Ltd.; the amino resin is selected from CYMEL250 and / or CYMEL370N of Cytec Chemical; The silane coupling agent is selected from one or a combination of KH-550, KH-560, KH-570, KH-580, KH-590, KH-902, KH-792, and KH-903 produced by Dow Corning; The auxiliary agent includes one or a combination of antioxidants, light aging agents and leveling dispersants.

8. The composite coating according to claim 7, characterized in that The antioxidant is selected from BASF's B215; the light aging agent is selected from Rianlon's UV944; the leveling dispersant is selected from BYK-345, BYK-187, BYK-192 or a combination thereof.

9. The composite coating according to claim 1, characterized in that The metal primer is selected from Nippon Paint's AR3500 (T) silver primer.

10. The method for preparing a composite coating according to any one of claims 1 to 9, wherein: The steps include: Spraying metal primer on the surface of the substrate to obtain a base coat after surface drying; Continue spraying the easy-identification functional composition on the base coating layer, and obtain an easy-identification layer after the surface is dried; The coating is dried naturally or baked at room temperature to completely dry the primer layer and the easily identifiable layer to obtain a composite coating.

11. The preparation method according to claim 10, characterized in that: The substrate is selected from a metal substrate or a non-metal substrate; The metal substrate is selected from tinplate or stainless steel; the non-metallic substrate is selected from PP plastic board.

12. Use of the composite coating according to any one of claims 1 to 9 in intelligent automobile coating and intelligent robot coating.

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