Wide-angle full-waveband automobile safety paint structure based on inverse reflection mechanism

Abstract

The application discloses a wide-angle full-waveband automobile safety paint structure based on a retroreflective mechanism and belongs to the technical field of automobile painting and automatic driving cooperative sensing. The structure comprises, from the substrate outward, an anticorrosion base coating, a full-waveband reflection-increasing base coating, a glass microsphere-containing color paint layer and a transparent clear varnish top layer. The glass microsphere group is an optional system, which comprises transparent glass microspheres and aluminum-plated glass microspheres, and the use proportion can be adjusted according to the color of the paint. Through the directional retroreflective mechanism of the glass microspheres, the Lambertian diffuse reflection of the traditional paint is replaced, and wide-angle and high-efficiency signal back transmission is realized in the full-waveband range of 400-1550 nm. The structure can significantly improve the detection distance and recognition accuracy of a laser radar and a vision system on a vehicle, especially can still maintain a reflection intensity of more than 50% under a 60-degree large incident angle, reduce the algorithm power consumption of the sensing system by more than 40%, effectively prolong the safety decision-making time of the automatic driving, and improve the driving safety.

Description

Technical Field

[0001] This invention relates to the field of automotive body coating materials and autonomous driving collaborative perception technology, specifically to a multi-layer retroreflective automotive paint coating structure that can simultaneously cover the entire 400-1550nm wavelength band (visible light + a full range of automotive LiDAR), improves wide-angle recognition performance through the directional retroreflection mechanism of glass microspheres, is compatible with all-color automotive paints and various mainstream automotive paint resin systems, and enhances the safety redundancy of autonomous driving and reduces the consumption of perception computing power from the source of perception. Background Technology

[0002] Currently, autonomous driving perception is divided into two main technical routes: active LiDAR perception and passive pure vision perception. LiDAR covers the three mainstream wavelength bands of 905nm, 1064nm, and 1550nm, while pure vision systems rely on 400-700nm visible light imaging. Both rely on the optical reflection signals of targets to complete identification, ranging, and classification. The nominal detection range of vehicle-mounted LiDAR is generally tested based on targets with 10% reflectivity: 905nm band main radar is nominally rated at 150-200m, and 1550nm band high-performance radar is nominally rated at 200-250m.

[0003] However, in real-world driving scenarios, ordinary dark-colored factory paint has a reflectivity of only 5%-8% for 905-1550nm near-infrared lasers, which is lower than the industry's general benchmark testing conditions. This results in the effective detection distance being significantly reduced to less than 50% of the nominal value, only 60-100m, which cannot meet the safe braking distance requirements under high-speed conditions. At the same time, ordinary paint is a typical Lambertian diffuse reflector, and the reflection intensity is further attenuated at large angles, making the risk of missed detection in complex scenarios extremely high.

[0004] The existing technology mainly has the following problems: 1) Insufficient normal incidence detection range and severe lack of safety braking redundancy: The low reflectivity of dark paint reduces the effective detection range of the lidar to only 60-100m, which is insufficient to meet the safety braking distance requirements under high-speed conditions. Calculated at a vehicle speed of 120km / h (approximately 33.3m / s), the system's available decision-making braking time is less than 1.8s. After deducting system response and braking pressure build-up time, the effective decision redundancy is extremely short, resulting in a very high risk of high-speed rear-end collisions.

[0005] 2) Failure of recognition in large-angle scenes, highlighting safety hazards in complex road conditions: In urban intersections, curves, and lane-changing scenarios, the relative angle of vehicles is mostly in the range of 30°-60°. Due to the constraint of the attenuation of the Lambertian diffuse reflection angle, both LiDAR and vision systems have difficulty in stably capturing the outline of the vehicle body, and the probability of side collisions and scratches increases significantly.

[0006] 3) Low target signal-to-noise ratio and soaring computing power consumption: Vehicle targets with weak echo and low brightness require the perception algorithm to perform multi-frame accumulation, noise reduction, feature enhancement and repeated verification to complete the recognition. The computing power consumption of the perception module increases by more than 40%, squeezing the computing power quota of the decision planning and control execution modules. In severe cases, it can cause system response delay and create secondary security risks.

[0007] 4) Low recognition accuracy and frequent false positives and false negatives: Weak optical features result in low differentiation between the vehicle body and the road background, guardrails and debris. The algorithm has low target classification accuracy and high false negative rate, which can easily lead to decision-making errors such as incorrect braking and avoidance failure.

[0008] Therefore, it is of great significance to develop a type of automotive safety paint that overcomes the shortcomings of existing technologies, such as the attenuation of reflection intensity across the entire wavelength range at large angles, insufficient detection distance for autonomous driving, and high computational power consumption caused by the Lambert diffuse reflection mechanism of ordinary automotive paint. Summary of the Invention

[0009] To address the shortcomings of existing technologies, such as the attenuation of reflection intensity across the entire wavelength range at large angles due to the Lambertian diffuse reflection mechanism of ordinary automotive paint, insufficient detection distance for autonomous driving, and high computational power consumption, this invention provides a wide-angle, full-wavelength automotive safety paint structure based on an anti-reflection mechanism.

[0010] Specifically, from the metal substrate of the car body outwards, it includes an anti-corrosion base coating, a full-band anti-reflective base coating, a color paint layer containing glass microspheres, and a transparent clear coat top layer.

[0011] Specifically, the full-band anti-reflective base coating and the color paint layer containing glass microspheres are embedded with glass microspheres, while the transparent varnish top layer does not contain glass microspheres.

[0012] Specifically, the glass microsphere assembly is an optional system, including transparent glass microspheres and hemispherical aluminized glass microspheres.

[0013] Specifically, the refractive index Nd of the transparent glass microspheres and the hemispherical aluminized glass microspheres is 1.7-2.5; Specifically, the thickness of the glass microsphere-containing color paint layer and the full-band anti-reflective base layer is 5-25 μm, the total dry film thickness is 10-50 μm, and the dry film thickness of the transparent varnish top layer is 20-40 μm.

[0014] Specifically, the glass microspheres are arranged in a multi-size gradient, with a particle size D50 ranging from 1 to 45 μm. The total amount of glass microspheres added accounts for 1% to 30% of the solids content of the paint.

[0015] Specifically, the ratio of transparent glass microspheres to aluminized glass microspheres in the glass microsphere assembly is adjusted according to the color of the vehicle paint.

[0016] Specifically, the transparent glass microspheres are a universal selection for all colors.

[0017] Specifically, the hemispherical aluminized glass microspheres are a preferred choice for dark-colored car paint.

[0018] Specifically, the aluminum coating layer of the aluminized glass microspheres is an opaque metal layer. Specifically, in the glass microsphere assembly, the aluminum-coated surface of the aluminized glass microspheres faces the side of the full-band anti-reflective undercoating, and the spherical cap faces the transparent varnish surface layer.

[0019] Specifically, the anti-corrosion primer is selected from one or more of cathodic electrophoretic epoxy resin, solvent-based epoxy anti-rust resin, or water-based epoxy anti-rust resin.

[0020] Specifically, the film-forming resin of the full-band anti-reflective undercoat is selected from one or more of waterborne polyurethane, epoxy-modified polyurethane, acrylic polyurethane, waterborne acrylic, and modified polyester.

[0021] Specifically, the full-band reflective undercoat is filled with infrared reflective material, namely flake-shaped nano-aluminum silver powder and titanium dioxide filler, which has high reflectivity across the entire 400-1550nm wavelength band.

[0022] Specifically, the film-forming resin containing the glass microsphere-based paint layer is selected from one or more of thermosetting acrylic acid, thermoplastic acrylic acid, acrylic polyurethane, modified polyester, and amino acrylic acid.

[0023] Specifically, the paint structure avoids the angular attenuation characteristics of Lambertian diffuse reflection through the directional retroreflection mechanism of the glass microsphere array. In the full wavelength range of 400-1550nm, the retroreflection coefficient retention rate is ≥50% when the incident angle is 60°, and the effective recognition angle range is ≥±60°.

[0024] Specifically, the film-forming resin of the transparent varnish top layer is selected from one or more of polyurethane, acrylic acid, amino acrylic acid, and fluorocarbon.

[0025] Specifically, the transparent varnish layer has high transmittance across the entire 400-1550nm wavelength band and completely seals the glass microspheres to provide wear-resistant and weather-resistant protection.

[0026] A mass production spraying process for a wide-angle, full-band automotive safety paint structure based on retroreflection mechanism is characterized by the step-by-step spraying of an anti-corrosion primer, a full-band anti-reflection primer, a color paint layer containing glass microspheres, and a clear coat topcoat, followed by unified high-temperature baking and cross-linking. This process is compatible with existing automotive painting production lines and various mainstream coating resin systems.

[0027] Application of a wide-angle, full-band automotive safety paint structure based on retroreflection mechanism in improving the accuracy of full-band, large-angle recognition in autonomous driving, extending the safety decision-making time of autonomous driving, and reducing the perception computing power of autonomous driving.

[0028] It has the following beneficial effects: (1) This invention significantly extends the braking decision window and substantially reduces the risk of high-speed accidents: In the case of direct incidence, the effective detection range of the lidar on dark-colored vehicle bodies is increased from 60-100m to over 150m (the all-aluminum glass microsphere solution can reach over 170m). Under high-speed conditions of 120km / h, the system's decision-making braking time is greatly extended, reducing the risk of accidents. The available decision-making braking time of the system is extended from less than 1.8s to over 4.5s, and after deducting the response and pressure build-up time, a safety redundancy of over 3s is still reserved, reducing the risk of accidents by more than 70%.

[0029] (2) The present invention improves the wide-angle performance across the entire band and significantly enhances the stability of recognition in all scenarios: the effective recognition incident angle is widened from ±15° of ordinary car paint to over ±60°. At a large incident angle of 60°, the retention rate of the retroreflection coefficient across the entire band is increased from 15%-20% of ordinary car paint to over 50% (over 60% for the all-aluminum-coated glass microsphere solution). The target miss rate is reduced by 65% ​​in large-angle scenarios such as urban intersections, curves, and lane changes, and the risk of side collisions and scratches is significantly reduced.

[0030] (3) This invention reduces the consumption of perception computing power and releases system computing resources: the signal-to-noise ratio of the target signal is greatly improved, and the computing power occupation of the perception module is reduced by more than 40%. The released computing power can be allocated to modules such as decision planning and cockpit interaction, avoiding system delays caused by computing power bottlenecks and improving the operational stability of the whole vehicle autonomous driving system.

[0031] (4) This invention improves the recognition accuracy and reduces false positives and false negatives: the optical distinction between the vehicle body and the background is significantly improved, the target classification accuracy of the algorithm is improved by more than 15%, the false negative rate is reduced by 60%, the false braking and ineffective avoidance are reduced, and the driving comfort and driving safety are improved.

[0032] (5) The present invention offers two options for full color coverage: the transparent glass microsphere option is compatible with all color car paints without compromising the original color texture; the hemispherical fully aluminized glass microsphere option is specifically optimized for dark car paints and offers superior performance. Both options cover all mass-produced car body colors.

[0033] (6) The present invention has high mass production adaptability and controllable cost: the film-forming resins of each layer cover the mainstream system of the automotive coating industry, the process does not require special modification, the cost increase of a single vehicle coating is extremely low, and it has the value of large-scale mass production promotion. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure and incident refracted light of a wide-angle full-band automotive safety paint structure based on retroreflection mechanism according to the present invention. Reference numerals: 1-Car body metal substrate; 2-Anti-corrosion primer; 3-Full-band anti-reflective primer; 4-Color paint layer containing glass microspheres; 41-Transparent glass microspheres; 42-Aluminized glass microspheres; 5-Transparent clear coat. Detailed Implementation

[0036] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0037] The following detailed description of the implementation method of the present invention is in conjunction with the accompanying drawings. The description is only a partial embodiment and not all embodiments. For clarity, representations and descriptions unrelated to the present invention are omitted in the drawings and description.

[0038] To provide a clearer understanding of the technical features, objectives, and beneficial effects of this invention, the following detailed description of the technical solution is provided. Obviously, the described embodiments are only a portion of the embodiments of this invention, not all of them, and should not be construed as limiting the scope of implementation of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention.

[0039] Example 1 This embodiment provides a wide-angle, full-band automotive safety paint structure based on retroreflection mechanism.

[0040] In this embodiment, the wide-angle full-band automotive safety paint structure based on retroreflection mechanism includes, from the vehicle body substrate outwards: an anti-corrosion base coating, a full-band anti-reflection base coating, a color paint layer containing glass microspheres, and a transparent clear coat top layer.

[0041] In this embodiment, the glass microspheres are added only to the full-band anti-reflective base coating and the glass microsphere-containing color paint layer, while the clear coat layer does not contain microspheres.

[0042] In this embodiment, the total dry film thickness of the glass microsphere-containing color paint layer and the full-band anti-reflective primer layer is 10-50 μm, and the dry film thickness of the transparent varnish top layer is 20-40 μm.

[0043] In this embodiment, the glass microspheres are arranged in a multi-size gradient, with a particle size D50 ranging from 1 to 45 μm, and the total amount added accounts for 1% to 30% of the solid content of the paint.

[0044] In this embodiment, the glass microsphere assembly is an optional system, comprising transparent glass microspheres and hemispherical aluminized glass microspheres, which can be selected according to the vehicle paint color. Transparent glass microspheres: These are uncoated transparent glass microspheres with a refractive index of Nd = 1.8-2.5. They rely on a full-band anti-reflective coating on the bottom to complete the reflected light path, without obstructing the pigment particles in the paint. They are suitable for light-colored car paints such as white, silver, and light gray, as well as dark-colored car paints, making them a universal choice for all color series.

[0045] Hemispherical aluminized glass microspheres: The microspheres are hemispherically coated with an aluminum reflective layer. This aluminum layer directly integrates the reflective function, resulting in lower optical path loss and superior retroreflection efficiency. Because the aluminum layer is an opaque metallic layer, it is recommended for use with dark-colored car paints such as black, dark gray, and dark blue, maximizing performance gains with minimal impact on appearance.

[0046] In this embodiment, the specific components and functions of each layer are as follows: In this embodiment, the thickness of the anti-corrosion primer is 8-15 μm, and it is selected from one or more of cathodic electrophoretic epoxy resin, solvent-based epoxy anti-rust resin, and water-based epoxy anti-rust resin.

[0047] Used to isolate the substrate from corrosion, provide interlayer adhesion, and provide a flat substrate for the upper optical structure.

[0048] In this embodiment, the thickness of the full-band anti-reflective undercoat is 5-25 μm. The film-forming resin is selected from one or more of waterborne polyurethane, epoxy-modified polyurethane, acrylic polyurethane, waterborne acrylic, and modified polyester. The functional filler includes infrared reflective materials, namely flake-shaped nano-aluminum silver powder and titanium dioxide filler, which have high reflectivity across the entire 400-1550 nm wavelength band.

[0049] It is used to block the transmission loss of light across the entire spectrum, and to reflect the transmitted light back to the glass microspheres a second time, thereby increasing the echo intensity; it also fixes the bottom of the glass microspheres to ensure embedding stability.

[0050] In this embodiment, the paint layer containing glass microspheres has a thickness of 5-25 μm. The film-forming resin is selected from one or more of thermosetting acrylic, thermoplastic acrylic, acrylic polyurethane, modified polyester, and amino acrylic. The functional component disperses the aforementioned gradient-sized glass microspheres, which are then combined with conventional color pastes to achieve the vehicle body color.

[0051] The core is used to form a directional retroreflection unit through the spherical refraction-bottom reflection principle of glass microspheres, so that light returns along the original path of the incident direction, avoiding the angular attenuation constraint of Lambertian diffuse reflection.

[0052] In this embodiment, the thickness of the transparent varnish topcoat is 20-40 μm. The film-forming resin is selected from one or more of polyurethane, acrylic, amino acrylic, and fluorocarbon varnish resins. Nano-SiO2 wear-resistant filler may be added optionally. This topcoat has high transmittance across the entire 400-1550 nm wavelength band. It is used to completely seal the microspheres, isolating them from sand, rainwater, and ultraviolet radiation, ensuring the gloss and smoothness of the paint surface; and ensuring lossless transmission of light across the entire wavelength band.

[0053] In this embodiment, the retroreflection luminance coefficient performance of the glass microsphere material was tested at different observation angles and incident angles.

[0054] In this embodiment, the glass microspheres have a material size of 15-20 μm. The performance test results are shown in Table 1. Table 1 In this embodiment, as shown in Table 1,

[0055] The retroreflection brightness of transparent glass microspheres is not highest when light is directly incident, but rather increases with increasing incident angle. At an observation angle of 12', as the incident angle increases from 5° to 30°, its brightness increases from 1.63 cd·lx. -1 ·m -2 Steadily increased to 12.0 cd·lx -1 ·m -2 Its retroreflective properties are actually better utilized when light shines at a certain angle (not perpendicular).

[0056] Its brightness is highly sensitive to changes in the observation angle, decreasing significantly as the observation angle increases. At an incident angle of 30°, when the observation angle increases from 12' to 1°30', its brightness decreases from 12.0 cd·lx. -1 ·m -2 It dropped sharply to 3.27 cd·lx -1 ·m -2 The retroreflected light from transparent glass microspheres is mainly concentrated within a narrow angular range very close to the light source. At a specific non-perpendicular incident angle, transparent glass microspheres can produce a brightness peak, and their reflected light energy is highly concentrated near the light source.

[0057] Under all test conditions, the aluminized glass microspheres exhibited extremely high brightness values. At an observation angle of 12', the brightness value remained stable at 40 cd·lx. -1 ·m -2 The highest value reached was 41.9 cd·lx. -1 ·m -2Even when the observation angle increases to 1°30', its brightness value remains at 8 cd·lx. -1 ·m -2 above.

[0058] The brightness of aluminized glass microspheres is almost unaffected by changes in the incident angle. At an observation angle of 12', regardless of whether the incident angle is 5° or 40°, its brightness value consistently ranges from 40.4 to 41.9 cd·lx. -1 ·m -2 It fluctuates within an extremely narrow range. Even when light shines from a very oblique angle, it still maintains an almost constant and extremely high reflectivity.

[0059] The brightness of aluminized glass microspheres decreases as the observation angle increases, but its absolute value remains high. At a large angle of incidence of 40°, when the observation angle increases from 12' to 1°30', its brightness increases from 40.4 cd·lx. -1 ·m -2 Decreased to 8.97 cd·lx -1 ·m -2 Although it has decreased, it is still far superior to the performance of transparent microspheres under any conditions.

[0060] Aluminized glass microspheres can continuously provide stable and high-intensity retroreflection signals over a wide range of incident and observation angles. In particular, their performance does not degrade when incident at large angles, making them an ideal choice for wide-angle and long-distance detection.

[0061] Example 2 This embodiment is an extreme use case of Embodiment 1.

[0062] In this embodiment, the glass microsphere assembly uses fully transparent glass microspheres.

[0063] In this embodiment, the specific processing method of the wide-angle full-band automotive safety paint structure based on retroreflection mechanism is as follows: Substrate pretreatment: Phosphating, degreasing and dust removal of automotive steel sheets; Epoxy anti-corrosion primer: cathodic electrophoretic epoxy resin, dry film thickness 10μm, baked and cured at 140℃; Full-band anti-reflective base coating: 70 parts waterborne polyurethane resin, 20 parts flake nano aluminum silver powder, 6 parts titanium dioxide, 4 parts additives, sprayed dry film thickness 7μm, pre-baked at 80℃. The color paint layer containing glass microspheres consists of 65 parts of water-based thermosetting acrylic resin, 20 parts of gradient-size transparent glass microspheres (60% of which have a large particle size of D50=15μm and 40% have a small particle size of D50=7μm), 12 parts of color paste, and 3 parts of dispersing agent. The dry film thickness after mist spraying is 6μm. The total dry film thickness of the color paint and primer is 13μm. Clear varnish topcoat: water-based polyurethane varnish, dry film thickness of 25μm after spraying; Overall curing: Bake at a constant temperature of 135℃ for 25 minutes.

[0064] In this embodiment, the performance of a wide-angle full-band automotive safety paint structure based on retroreflection mechanism was tested, and the specific results are shown in Tables 2, 3 and 4.

[0065] Example 3 This embodiment is an extreme use case of Embodiment 1.

[0066] In this embodiment, the glass microsphere assembly uses fully aluminized glass microspheres.

[0067] In this embodiment, the specific processing method of the wide-angle full-band automotive safety paint structure based on retroreflection mechanism is as follows: Substrate pretreatment: Phosphating, degreasing and dust removal of automotive steel sheets; Epoxy anti-corrosion primer: cathodic electrophoretic epoxy resin, dry film thickness 10μm, baked and cured at 140℃; Full-band anti-reflective base coating: 78 parts waterborne polyurethane resin, 12 parts flake nano aluminum silver powder, 6 parts titanium dioxide, 4 parts additives, sprayed dry film thickness 6μm, pre-baked at 80℃. Color paint layer containing glass microspheres: 65 parts water-based thermosetting acrylic resin, 18 parts graded-size aluminized glass microspheres (60% large particle size D50=15μm, 40% small particle size D50=7μm, aluminized side facing the primer), 14 parts dark pigment, 3 parts dispersant, with a dry film thickness of 7μm after mist spraying; total dry film thickness of color paint + primer is 13μm. Clear varnish topcoat: self-healing polyurethane varnish, dry film thickness 25μm; Overall curing: Bake at a constant temperature of 135℃ for 25 minutes.

[0068] In this embodiment, the performance of a wide-angle full-band automotive safety paint structure based on retroreflection mechanism was tested, and the specific results are shown in Tables 2, 3 and 4.

[0069] Performance test results Table 2 shows the comparison data of normal incident optics and sensing performance. Table 3 shows the comparison data of retroreflection retention rate across the entire wide-angle band. Table 4 shows the comparison of safety redundancy under high-speed operating conditions (vehicle speed of 120km / h). Table 2 Table 3 Table 4 Performance test data shows that both schemes of the wide-angle, full-band automotive safety paint structure based on retroreflection mechanism proposed in this application significantly improve the retroreflection coefficient of the paint. The transparent microsphere scheme increases it to 4.3 times that of ordinary paint, while the aluminized microsphere scheme reaches 5 times, providing extremely strong echo signals for the lidar.

[0070] The effective detection range of lidar has been increased from 72m to 156m and 172m respectively, more than doubling, greatly expanding the sensing range.

[0071] The pure visual nighttime recognition distance has also been significantly improved, from 35m to 52m and 55m respectively, enhancing the camera's perception capabilities in low-light environments.

[0072] The accuracy of single-frame recognition has increased from 72% to 91% and 94% respectively, meaning that the system can more reliably identify targets and reduce false positives and false negatives.

[0073] The computing power consumption of the perception module has been significantly reduced to 58% and 52% of the baseline value, saving more than 40% of computing power resources, which can be allocated to other modules such as decision planning, thereby improving the efficiency of the entire vehicle system.

[0074] According to the data in Table 3, the two schemes of the wide-angle, full-band automotive safety paint structure based on retroreflection mechanism proposed in this application far exceed the performance of ordinary paint and the theoretical limit of Lambertian diffuse reflection when dealing with large-angle incident light. At a large angle of 60°, the reflection intensity of ordinary paint will decrease to 15%-20% of that at normal incidence. The transparent microsphere scheme can maintain 52%-58% of the reflection intensity. The aluminized microsphere scheme performs even better, maintaining >60% of the reflection intensity, demonstrating its superior wide-angle detection capability.

[0075] Based on the simulation data in Table 4 at a vehicle speed of 120 km / h, the two schemes of the wide-angle full-band automotive safety paint structure based on retroreflection mechanism proposed in this application significantly improve driving safety redundancy. Ordinary paint, after deducting system response and braking pressure build-up time, leaves only about 1.1 seconds of effective decision-making time, which is extremely risky. The transparent microsphere scheme extends the decision redundancy time to about 3.9 seconds. The aluminized microsphere scheme further extends it to about 4.4 seconds, providing a valuable time window for emergency avoidance.

[0076] This application presents a wide-angle, full-band automotive safety paint structure based on retroreflection. The gloss levels of two schemes (90 GU and 89 GU) are very close to those of ordinary paint (92 GU), indicating that the addition of microspheres did not significantly sacrifice the paint's appearance and texture. The paint film adhesion both meet Level 1 standards, demonstrating a strong bond between the new coating structure and the substrate, satisfying automotive-grade reliability requirements.

[0077] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A wide-angle, full-band automotive safety paint structure based on retroreflection mechanism, comprising, from the metal substrate of the vehicle body (1) outwards, an anti-corrosion primer (2), a full-band anti-reflection primer (3), a color paint layer containing glass microspheres (4), and a transparent clear coat top layer (5); characterized in that: The full-band anti-reflective base coating (3) and the color paint layer (4) containing glass microspheres are embedded with glass microspheres, while the transparent clear varnish top layer (5) does not contain glass microspheres. The glass microsphere assembly is an optional system, including transparent glass microspheres (41) and hemispherical aluminized glass microspheres (42). The refractive index Nd of the transparent glass microspheres (41) and the hemispherical aluminized glass microspheres (42) is 1.7-2.5; The thickness of the glass microsphere-containing color paint layer (4) and the full-band anti-reflective base layer (3) are both 5-25 μm, the total dry film thickness is 10-50 μm, and the dry film thickness of the transparent varnish top layer (5) is 20-40 μm.

2. The wide-angle, full-band automotive safety paint structure based on retroreflection mechanism according to claim 1, characterized in that, The glass microspheres are arranged in a multi-size gradient, with a particle size D50 ranging from 1 to 45 μm; the total amount of glass microspheres added accounts for 1% to 30% of the solids in the paint.

3. The wide-angle full-band automotive safety paint structure based on retroreflection mechanism according to claim 2, characterized in that, The ratio of transparent glass microspheres (41) to aluminized glass microspheres (42) in the glass microsphere group is adjusted according to the color of the car paint; the transparent glass microspheres (41) are a universal selection for all colors; the hemispherical aluminized glass microspheres (42) are a preferred selection for dark-colored car paint, and the aluminized layer of the aluminized glass microspheres (42) is an opaque metal layer.

4. The wide-angle, full-band automotive safety paint structure based on retroreflection mechanism according to claim 1, characterized in that, The aluminized surface of the aluminized glass microspheres (42) in the glass microsphere group faces the side of the full-band anti-reflective undercoating (3), and the spherical cap faces the transparent varnish surface layer (5).

5. A wide-angle, full-band automotive safety paint structure based on retroreflection mechanism according to claim 1, characterized in that, The anti-corrosion base coating (2) is selected from one or more of cathodic electrophoretic epoxy resin, solvent-based epoxy anti-rust resin or water-based epoxy anti-rust resin; the film-forming resin of the full-band reflective base coating (3) is selected from one or more of water-based polyurethane, epoxy-modified polyurethane, acrylic polyurethane, water-based acrylic, modified polyester; the full-band reflective base coating (3) is filled with infrared reflective material, namely flake nano aluminum silver powder and titanium dioxide filler, which has high reflectivity in the full-band of 400-1550nm.

6. A wide-angle, full-band automotive safety paint structure based on retroreflection mechanism according to claim 1, characterized in that, The film-forming resin of the glass microsphere-containing paint layer (4) is selected from one or more of thermosetting acrylic, thermoplastic acrylic, acrylic polyurethane, modified polyester, and amino acrylic.

7. A wide-angle, full-band automotive safety paint structure based on retroreflection mechanism according to claim 1, characterized in that, The paint structure avoids the angular attenuation characteristics of Lambertian diffuse reflection through the directional retroreflection mechanism of glass microspheres. In the full wavelength range of 400-1550nm, the retroreflection coefficient retention rate is ≥50% when the incident angle is 60°, and the effective recognition angle range is ≥±60°.

8. A wide-angle, full-band automotive safety paint structure based on retroreflection mechanism according to claim 1, characterized in that, The film-forming resin of the transparent varnish top layer (5) is selected from one or more of polyurethane, acrylic acid, amino acrylic acid, and fluorocarbon; the coating has high transmittance in the full wavelength range of 400-1550nm and completely seals the glass microspheres to provide wear-resistant and weather-resistant protection.

9. A mass production spraying process for a wide-angle, full-band automotive safety paint structure based on retroreflection mechanism as described in any one of claims 1-8, characterized in that, The anti-corrosion base coat (2), the full-band anti-reflective base coat (3), the color paint layer containing glass microspheres (4), the transparent clear coat (5) are sprayed in stages and then uniformly baked at high temperature for cross-linking, which is compatible with existing automotive painting production lines and various mainstream coating resin systems.

10. The application of the wide-angle full-band automotive safety paint structure based on retroreflection mechanism as described in any one of claims 1-8 in improving the accuracy of full-band large-angle recognition in autonomous driving, extending the safety decision-making time of autonomous driving, and reducing the perception computing power of autonomous driving.

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