Since advanced driver-assistance systems (ADAS) and other cutting-edge self-driving innovations hit the automotive market, reliable LiDAR (Light Detection and Ranging) and RADAR (Radio Detection and Ranging) systems are crucial in the development of advanced self-driving vehicles. One significant challenge in this relation, is to guarantee clear visibility of those systems even in the harshest environmental conditions. For the sensor cover, especially the accretion of snow and ice as well as fogging is a significant issue that needs to be solved.
To ensure visibility during winter time, the RADAR and LiDAR sensor covers are currently equipped with wire based heating solutions. This state of the art solution is coming with some technological challenges during the manufacturing process, that is causing significant scrap rates. The homogeneity of the sensor cover temperature is often inadequate and overheating or even burning issues have been detected.
Since the required cooling air inlet of electrified vehicles is significantly smaller than that of a combustion engine car, large covers are used in the vehicleβs frontend to mimic characteristic air inlet designs by incorporating a decorative, opaque foil into the otherwise transparent cover. These grills house all kind of sensors and cameras and thus, need to be heated to ensure a clear view of those devices, so a wire based heating system is added in addition to the decorative film.
As an alternative to the technology currently on the market, ATT is offering two variants, both being screen printed onto (transparent) polycarbonate foils, saving process costs with respect to the currently available embedded wire technology:
Alternative to the wire based heaters
Instead of using wire based heating systems, printed heating films based on silver are our go. This heating film is back moldable and transparent, and can be easily integrated in the back injection process, thus reducing the scrap rate significantly:
- Heating films are thermoformable, so even very complex geometries can be heated homogenously.
- The high power density of our heating solutions (up to 0.4 W/cm2) leads to improved deicing times (a 2 mm ice layer can be melted in less than 180 seconds)
- Thin (starting from 175 ΞΌm) and transparent in the wavelength relevant for RADAR and LiDAR.
- RADAR: below -0.5 dB one-way attenuation (at 76 β 77 GHz)
- LiDAR: > 90% transmittance of the electrode pattern
- Visual range: > 90 % transmittance of the heating film
Heaters featuring an inherent PTC-Effect
This is our flagship technology that features a PTC effect based on a combination of silver and carbon components, and thus enables on-demand heating of the sensor cover which we believe will be a future requirement in terms of efficiency and safety.
- Due to the Positive-Temperature-Coefficient (PTC) effect of our solution, the heating film comes with intelligence. The PTC effect describes the phenomena that the electric resistance increases with the temperature. Due to this effect, heat is only applied to areas of the cover that show ice or snow accretion as well as fogging.
- The PTC effect enables significantly increased power densities, resulting in faster de-icing rates (ready to use scenario) than any other solution currently available on the market.
- On-demand heating reduces the heating power significantly which leads to an efficient and range improving operation.
- Overheating or even burning issues can be eliminated because of the self-regulating effect of the heating film. Even without temperature sensors, the maximum specified temperature can not be exceeded.
- Transparency in relevant wavelength regimes
- RADAR: below -0.5 dB one-way attenuation (at 76 β 77 GHz)
- LiDAR: > 90% transmittance of the electrode pattern
- Visual range: > 90% transmittance of the electrode pattern
- Heating films are thermoformable, so even very complex geometries can be heated homogenously.
- The high power density of our heating solutions (up to 1.5 W/cm2) leads to improved deicing times (a 2 mm ice layer can be melted in less than 60 seconds).
- Want to add an ice or humidity sensor so make sure the heating is only turned on when needed? This is possible as well using our capacitive sensor technology which can be directly integrated in the cover at defined positions.
How to work together with us?
ATT is your serial supplier when it comes to highly efficient and intelligent heating solutions for Camera as well as RADAR and LiDAR sensor covers. We typically supply our solutions to a Tier 1 supplier but are also capable to team up with partners focusing on injection molding to directly supply our products to the OEM.
We are also happy to support our partners in research driven projects. Please feel free to contact us with your requirement, idea or ready-made RFQ.
