Evaluating the easy-to-clean performance of UV-durable hydrophobic coatings for sensor signal enhancement of autonomous vehicles under fouling conditions

Emerging autonomous driving technology has the potential to bring revolutionary changes to our society in the coming years. One key emerging technology for enabling autonomous driving is the UV-durable easy-to-clean coatings for all sensors, including vision sensors and ranging sensors, for autonomous vehicles. UV-durable hydrophobic (UVH) coatings on sensor surfaces will provide both UV durability and easy-to-clean performances. A laboratory testbed was constructed to evaluate the easy-to-clean performance of the UV-durable hydrophobic coatings on cameras, a light detection and ranging (LiDAR) system, and a radar, under laboratory-generated fouling conditions, including light rain and heavy rain, light mud and heavy mud, fog, and bugs. Several metrics such as modulation transfer function 50 loss (MTF50_loss), signal-to-noise ratio (SNR), reflectivity and the number of returned laser dots, and amplitude are used to measure the performance of sensors. The evaluation results indicate significant benefits of using UVH coatings to enhance the signal reading of sensors under inclement weather. In addition, experimental data indicated that a coating stack of UVH coatings on a sol-gel hard coat will significantly enhance UV durability. Further, UVH coatings have shown low ice adhesion, with their performance comparable to the best antiice coatings.