By Andrey Slivka
Artificial intelligence will power the automated driving revolution. So will improvements in connectivity and machine vision. But don’t forget about coatings — the paints and other substances that will cover autonomous vehicles (AVs). These inconspicuous products will be the unsung heroes of the driverless future.
The first area where coatings will play a fundamental role for AVs is in navigation. Coatings will be crucial to the variety of sensors that will “allow vehicles to communicate with each other, to see each other, and to detect obstacles and where the road is,” said David Bem, CTO and vice president of science and technology at PPG. These sensors, including cameras, radars and other devices, will facilitate everything from nimble feats of parking to the orderly progression of thousands of cars moving at highway speed.
Lidar (light detection and ranging) sensors are among the most ingenious of these devices. They work by pulsing light at objects, then using the speed of the reflection to calculate distance and position. The trouble is that darker-colored paints don’t reflect those pulsations particularly well. In one test, for example, a black car reflected back just half of the signals that a white car did, making it dramatically less “visible.”
That’s where the right coatings come in.
PPG, Bem said, has designed dark coatings that allow the light to penetrate down toward a reflective under-layer. The signal “bounces back off” this substratum and returns to the sensor instead of getting absorbed. Bem calls this PPG’s “eggplant” technology, because the coloring of an eggplant functions in the same light- and heat-reflective way.
Minimizing Leakage, Repelling Mud
Another area where coatings will prove important is in minimizing radio frequency leakage. That’s where electromagnetic signals drift and bleed into one another, creating cross talk that can degrade how well equipment works. Bem says that technology from PPG’s Aerospace business, such as dielectric absorbers, will ensure that signals don’t get mixed up and impair one another’s performance.
PPG scientists are also overcoming a basic liability of the sensor: that it can get covered with ice or mud. The solution, Bem said, is “self-cleaning technology” — coatings that “modify the surface of the vehicle” so that dirt and water slide right off. The result is that nothing obstructs the signals.
But it’s not only on the outside of the vehicle that coatings will be key. They’ll play roles inside, too.
Automated driving is going to change our relationship to cars. By facilitating car sharing, it will make the car more akin to a taxi cab or a city bus than to the personal cocoon that’s the automobile as we know it today. And cabs and buses, shared by thousands of people, are not the cleanest places in the world.
We’ll therefore see the development of “functional coatings” with “antimicrobial properties or antiviral properties,” Bem said — desirable properties in situations “where you’re going to have a large number of people sharing the same vehicle.” AVs will no doubt be outfitted with screens on which passengers can work or play, and those screens need to be stain-, smudge- and fingerprint-resistant.
Under the hood, meanwhile, an AV’s battery cell packs will also depend on coatings: protective coatings on the bottom, to guard against gravel and other debris thrown up from the road, and heat-conducting coatings on top. Batteries can get hot. “You want to make sure that heat can dissipate out of the system in a safe way,” Bem said.
Coating The Landscape
But it’s not only on the vehicle itself that high-tech coatings will do their work. It’s also on road infrastructure — on guardrails, road dividers, bridge bulwarks, signposts and all of the other roadscape elements that driverless cars will have to see. These elements will require coatings that make them perfectly visible to AV sensors.
Developing those coatings can pose some interesting challenges. The bright, reflective coating that makes a road sign easy for the human eye to see can, Bem said, “amplify the signal so much that it saturates the sensor, which effectively blinds it.” Researchers have been developing “wavelength management technologies” to overcome such challenges. PPG already has one coating technology that lets its users better manage the reflectivity of specific wavelengths.
Those are just several of the uses advanced coatings will be put to when automated driving takes over our roads. The Silicon Valley titans with their startling technology attract most of the attention in automated driving. But it’s getting a big push forward from innovative coatings that function with quiet effectiveness, doing crucial work that, if all goes right, users of driverless tech will never even notice.
Andrey Slivka is senior editor at Forbes BrandVoice.