On the streets of Munich, a driverless taxi is taking passengers to their destination. The “PM0.3 filtration efficiency 99.97%” indicator light on the in-car air quality display is quietly lit—this is not only a reflection of comfort but also a crucial element ensuring the reliable operation of the autonomous driving system.
When discussing autonomous driving, people first think of LiDAR, artificial intelligence, and algorithms. However, in Munich, the capital of Bavaria, Germany, engineers are revealing a neglected truth: HEPA and ULPA filters, technologies that have silently worked in hospitals and chip factories, are becoming a key driving force for autonomous driving systems to achieve higher levels of safety.
Guardians of the Perception System: “Sharpening the Eyes” of LiDAR and Cameras
The “eyes” of autonomous driving—the sensor system—requires a level of cleanliness far exceeding human imagination. In the lab, researchers discovered that even micron-sized dust particles accumulating on the optical windows of lidar systems can cause signal attenuation of up to 23%. During rainy and humid seasons, imperceptible oil films and water stains on camera lenses can reduce the accuracy of image recognition algorithms by 15%.
“This isn’t just a cleaning issue, it’s a matter of continuous maintenance,” the project leader pointed out. “We can’t expect autonomous vehicles to stop and wipe their sensors every 200 kilometers.” The solution comes from the semiconductor industry—miniature ULPA filter modules specially developed for chip manufacturing plants. These modules create a “curtain” of clean airflow with a slightly positive pressure, continuously preventing particulate matter from adhering to the optical surface. Test data shows that this design can extend the sensor cleaning interval to five times that of traditional solutions.
Temperature Control and Particulate Protection for Computing Platforms
In real-world road testing, engineers face another challenge: high-performance computing units are both heat sources and particulate matter sensitive points.
The computing platforms of autonomous vehicles contain multiple GPUs and processors, and their cooling requirements mean they must exchange air with the outside environment. However, pollen, industrial particulate matter, and brake pad wear particles in the air can enter the system and deposit on precision circuit boards.
By drawing inspiration from aerospace technology, engineers implemented a three-stage filtration system: a primary filter intercepts leaves and insects, a secondary filter removes pollen, and a HEPA filter, positioned close to the heatsink, ensures that 99.97% of 0.3-micron particles entering the computing unit are removed. This design not only protects the hardware but also maintains stable heat dissipation efficiency, allowing the computing platform to operate at peak performance continuously—crucial for handling complex urban traffic conditions.
Manufacturing：The “Clean Birth Certificate” for Autonomous Vehicles
The precision of autonomous driving technology even extends to the manufacturing process. Calibration of lidar and cameras must be performed in an ISO 6 cleanroom environment; any dust falling onto the calibration plates can lead to batch-wide perception deviations. This stringent requirement for manufacturing cleanliness has prompted filtration technology suppliers like Trenntech to develop customized solutions for the automotive industry—costing less than semiconductor factories but exceeding the standards of traditional automakers.
The Road Ahead
As autonomous driving technology advances to higher levels, its demand for clean environments will only continue to increase. From the ground to the sky, clean technology remains the foundation of the reliability of autonomous driving systems. HEPA and ULPA filters are moving from behind the scenes to the forefront; they are no longer simple auxiliary components, but key technologies that ensure the reliable perception, accurate calculation, and safe operation of autonomous driving systems in the real world. Trenntech is committed to continuously developing HEPA and ULPA products suitable for the times.