The race is on. Engineers are working to develop autonomous vehicles that are safe, efficient, and affordable. To do so, engineers are perfecting LiDAR systems; one of the main components in autonomous vehicles that are responsible for “seeing” the road.
LiDAR sensors emit pulses of light that bounce off objects, creating a 3D map of the area that helps steer a car safely on the road. The sensors are crucial to the functionality of autonomous vehicles, but engineers are noticing a problem when they test new LiDAR systems: water damage.
Although a device can be water proof it’s never water vapor ingress proof as all materials allow water vapor to pass through them over time. That ingressed water combined with changing temperatures eventually causes condensation to build up on the sensors or the glass protecting it.
Water causes serious problems for LiDAR systems, including:
LiDAR sensors are protected by a housing or case of some kind. The materials vary, but in some cases, they include metal. When metal is exposed to water a series of reduction-oxidations reactions occur that corrode, or eat away the metal.
If the housing of the sensors corrode, they weaken and can shorten the lifespan of the sensors inside.
2. Short circuit wiring in PCB
Introducing water to any electrical component is problematic, but when it meets a printable circuit board it can cause a short circuit. In the absence of a fuse to short, water can increase the current running through the board, causing it to heat up, and possibly start a fire.
3. Picture deterioration
If water builds up on or near the sensors, it’s not able to do its job efficiently. The water is a barrier that could diminish the accuracy of the measurements taken, which could deteriorate the 3D map that’s generated. With a less-than-perfect map to rely on, the precision of autonomous vehicles decline.
The solution to LiDAR water damage
Many engineers discover water damage problems during the testing phase. After six months on the road, the housing starts to leak or condensation becomes a problem.
After spending time and money to produce a LiDAR system, engineers find themselves wondering how to fix the water problem in a post-design stage.
Due to post design space constraints many engineers turn to Polysorb injection molded parts/components that can be fit in or replace a current plastic component inside the assembly becoming the desiccant to absorb the water. Using a cavity or replacing an existing part as the desiccant eliminates the need for a complete redesign while addressing the problem in protecting the sensors from water damage.
While PolySorb can be added post-design, it’s often easier to incorporate the desiccant during the design or planning phase. The innovators of PolySorb have engineers that designers can consult with to find water prevention solutions early on.