Vehicle Coating Composition for LIDAR Detection and RADAR Transparency
Solution Overview
Problem
Existing vehicle coatings deteriorate LIDAR detectability and RADAR signal transparency due to specular or retroreflective properties, hindering accurate distance determination and object detection.
Innovation Solution
A coating comprising retroreflective microspheres and pigment flakes with a high aspect ratio, particularly where the median diameter of pigment flakes is greater than 35% of the median particle diameter of spherical glass beads, enhancing both LIDAR detectability and RADAR signal transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a clearcoat top layer with glossy appearance is applied to protect the vehicle, then aesthetic appearance is improved, but LIDAR detectability deteriorates due to specular reflection
Solution Approach 1:
The patent applies a composite coating system comprising a basecoat layer with retroreflective microspheres and pigment flakes, overlaid with a clearcoat top layer. This composite structure combines the aesthetic benefits of glossiness with the functional benefits of retroreflection, allowing LIDAR systems to detect the vehicle while maintaining visual appeal.
Solution Approach 2:
The patent creates different optical properties at different locations within the coating system. The basecoat layer contains retroreflective microspheres that provide directional reflection for LIDAR detection, while the clearcoat top layer provides specular reflection for aesthetic appearance. Each layer performs its specific function locally without compromising the other.
2Measurement precision
If retroreflective microspheres are added to improve LIDAR detectability, then measurement precision is improved, but coating complexity increases
Solution Approach 1:
The patent combines retroreflective microspheres and pigment flakes into a single basecoat layer that can be applied in one coating process. This merging of functional elements into a unified layer reduces the number of separate coating steps required, thereby managing complexity while achieving improved LIDAR detectability.
Solution Approach 2:
The basecoat layer serves multiple functions simultaneously: it provides color pigmentation, retroreflective properties for LIDAR detection, and a substrate for the clearcoat top layer. This multi-functionality reduces the need for separate specialized layers, simplifying the overall coating system.
3Illumination intensity
If metal flake pigments are used in bumper coating for aesthetic appearance, then visual appeal is improved, but RADAR signal transparency deteriorates
Solution Approach 1:
The patent changes the physical parameters of the pigment particles by using spherical glass beads with specific size ranges (D50 between 1-150 μm) and refractive indices (1.7-2.8). These parameter changes allow the particles to reflect LIDAR wavelengths effectively while being less interfering with RADAR signals compared to traditional metal flake pigments.
Solution Approach 2:
The patent uses pigment flakes with high aspect ratio that can provide color and visual appeal while having different optical properties than metal flake pigments. The combination of pigment flakes and spherical glass beads creates a coating that maintains aesthetic appearance while improving transparency to RADAR signals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Improves LIDAR detectability at increased angles and enhances RADAR signal transparency, allowing for accurate distance and contour determination, as well as improved visibility under visible light conditions.
Implementation Method 1
a basecoat layer consisting of 14.95-98.95 wt. % of binder, 1-85 wt. % of spherical glass beads... The coating improves not only the frontal view of the vehicle, but rather the whole LIDAR scannable contours of the vehicle.
Implementation Method 2
0.05-30 wt. % of pigment flakes chosen from the group consisting of metallic pigment flakes, pearlescent pigment flakes or a combination thereof... Lambertian reflectance is the property that defines an ideal matte or diffusely reflecting surface.
Implementation Method 3
The invention further relates to the use of spherical glass beads as a transparency improver for radio waves in a coating layer... Automotive RADAR sensors are usually integrated invisibly behind vehicle bumpers.
Data Source
AI summary
The present invention concerns a vehicle having a frame or coachwork, wherein at least part of the outer surface of the frame or coachwork is covered with a coating, said coating comprising at least two layers, wherein the outer two or three layers are: (a) a basecoat layer; (b) optionally a tinted clearcoat layer on (a); and (c) a clearcoat top layer on (a) or on (b); wherein the basecoat layer (a) consists of binder, spherical glass beads, pigment flakes and optionally further ingredients, wherein the median diameter D50 of said pigment flakes is greater than 35% of the median particle diameter D50 of said spherical glass beads. The present invention further concerns a Laser Imaging Detection And Ranging (LIDAR) process of the vehicle and the use of the vehicle or a coated substrate comprising said coating in Laser Imaging Detection And Ranging (LIDAR) of said vehicle or of said coated substrate; and/or to improve the visibility of said vehicle or of said coated substrate under visible light conditions; and/or to prepare a 3-dimensional image of said vehicle or of said coated substrate