Lately, Genesis has had a hard time drinking cold water. The sales volume was already worrying enough, but now there was an unexpected surprise. It had to recall 483 G90s (Genesis' flagship sedan) in North America because the cars would brake on their own without warning. What is going on?
A G90 owner said that when driving normally on the highway without any obstacles in front, the car would suddenly stop. After feedback to the dealer, Genesis was also very inefficient. It took engineers several months to figure out the culprit behind the scenes. It turned out that Savile Silver paint was to blame.
The aluminum powder content of this paint is extremely high, and it looks like countless small mirrors mixed in the paint.
It looks dazzling and high-end, but there is also a problem. When the car is at low speed or when the lane change assist is turned on, the signal reflected by these aluminum powder will directly confuse the millimeter wave radar in the front fender. This caused the radar to misunderstand that there was a car in the next lane and was about to hit it, triggering a sudden brake. This was quite scary.
Fortunately, the cases reported so far have not resulted in any serious consequences.
The solution after the recall is quite simple. Replace the car with a new front bumper beam assembly to block those scattered radar reflection signals. In addition to the recall, orders for the optional Savile Silver car paint have also been suspended. Orders will not be reopened until the problem is completely resolved.
In fact, the trouble Genesis encountered is not new in the aftermarket car clothing industry.
I believe some dealers must know that if your car has "multiple radars", after you choose those car covers that contain aluminum foil, copper layer, or conductive coating at the film shop, the knowledgeable boss will advise you not to apply them.
If you encounter someone who doesn't know how to do it, if they force it on you, the radar signal will be directly blocked, and the assisted driving function may fail.
There have been many car owners who applied electroplating film before, but found that the assisted driving function cannot be used after applying it. In the end, you have to either reattach it or cut off a piece of film so that the millimeter wave radar is not affected. This is a bit like Balenciaga's beggar style, which is really difficult to comment on.
Image source: 99 playing Weilai
What’s even more interesting is that there are really not many industry standards that can be used when it comes to how metallic paint affects radar signals.
Brother Neck checked and found that most of the current standards at home and abroad only stipulate parameters such as radar detection range and angle accuracy, and basically do not mention the impact of body materials and coatings on radar.
However, there is an exception. The "Interim Regulations on Automotive Radar Radio Management" issued by the Ministry of Industry and Information Technology in 2021 requires that the loss of radar signals penetrating car body materials in the 77-81GHz frequency band (the common range of automotive millimeter wave radars) shall not exceed 3dB, which means that at least 50% of the signal energy can pass through.
This is one of the rare mandatory official regulations on automotive radar penetration loss.
Therefore, the entire global automotive industry indeed lacks relevant regulations to guide the R&D and testing of car companies. Currently, it relies more on the consciousness and technology accumulation of car companies. Once the body design department and the intelligent driving team do not align the granularity, problems like Genesis may occur.
Of course, smart driving is well developed here in China, so there is more research on this area.
For example, the patent "A Design Method and Device for Automobile Millimeter Wave Radar Covers Matching Paint Layers" applied by FAW-Volkswagen in 2022 relies on mathematical models to calculate doorways and automatically match the optimal thicknesses of radar covers and paint layers so that radar waves can penetrate smoothly.
There is also an article published by Thalys in 2024, "Research on the Impact of Automotive Metallic Paint on Millimeter Wave Radar", which mentions how to reduce signal interference by controlling the paint formula. These are all car companies showing off their talents and trying to solve the problem of compatibility between metallic paint and radar.
In addition, upstream paint manufacturers are not idle either. If they could directly produce car paint with less interference to radar signals, wouldn't it save a lot of trouble at the source?
World-renowned paint giants such as PPG and Axalta have already set their sights on this direction, and have stated that they will launch low-radar reflectivity metallic paints optimized for ADAS systems, but they have not yet been rolled out on a large scale.
Domestic Kuncai Technology has made a Wavemaster series of pearlescent pigments, which are specially used for vehicles with assisted driving, drones and other equipment. What’s great about it is that it has no metal layer structure, but has a super strong metallic luster, and it does not delay the high transmittance of millimeter wave radar signals.
Brother Neck did not find out which car uses Wavemaster, but it is obvious that this will be an important technology path in the future. For example, Yatu High-tech, another domestic paint company, applied for a patent for "A Radar Perspective Automotive Paint and its Preparation Method" in July this year, in order to prevent the automotive paint from interfering with the transmission of radar signals.
It’s good. If we all work together, there are always more solutions than difficulties.
Talking about the Genesis recall, this guy really doesn’t sell many in China, so this is not a big industry earthquake and its influence is limited. But it is more like a signal, exposing the details and loopholes that are easily overlooked in the development process of automobiles.
Nowadays, everyone is competing for the computing power and algorithms of intelligent driving, and the detection range and accuracy of radar, but little attention is paid to seemingly inconspicuous aspects such as car paint and body materials. As a result, unexpected problems have been revealed.
Moreover, it is not enough for a few car companies and paint companies to figure it out on their own, they must have unified rules. Therefore, the ISO 13389 "Test Method for Detection Performance of Millimeter Wave Radar for Road Vehicle Exterior Perception", led by our Chinese experts, will be established in 2024.
This is a test method that specifically regulates the impact of body materials and coatings on millimeter-wave radar, and will be the world's first universal international standard. Of course, the launch cannot be that fast. After all, the formulation process requires the cooperation of dozens of experts from around the world, which will naturally take some time. If everything goes well, it will be released in 2026 or 2027.
You see, this is real progress. China can now not only build useful cars, but also take the lead in setting standards for the industry and turn our practical experience into internationally accepted standards. Let the global automotive industry avoid detours in the field of assisted driving, and allow users to feel more at ease when using their cars, with fewer frightening moments of "self-braking".