Investigation of the Effectiveness of a Passive Device for Soiling Mitigation for Vehicle Side-Cameras 2020-01-0699

The development of modern autonomous automotive technology depends heavily on the reliable performance of external sensors that are vulnerable to soiling. Existing active cleaning devices, such as washers and wipers, are relatively complex and expensive. Furthermore, little research has been done on alternative soiling mitigation strategies and devices for sensors. With the emerging trend of replacing side-mirrors with camera monitor systems, it is important for such systems to stay clean in adverse weather in order to provide critical navigation information. To meet this need, a passive aerodynamics-based cleaning device was investigated. A converging vent device was integrated into the side-camera housing and the subsequent degree of soiling was estimated at a wind speed of 20 m/s (72 km/h), representing urban and suburban driving speeds. The vent outlet height and outlet jet angle of the vent device were varied and the variants were compared to the non-vented reference model. The degree of soiling was evaluated experimentally and computationally. The variants were 3D-printed and sprayed with water in wind tunnel tests, where the degree of soiling was quantified by water droplet counts. Numerical simulation was also performed using ANSYS® Fluent to visualize the airflow patterns. The results from wind tunnel tests and CFD suggest that the vent device is effective in reducing soiling for up to 94%. This investigation demonstrated that the outlet geometry of a passive vent device significantly affects the deposition aerodynamics and type of soiling on a sensor and provides insight for further design and development of such devices.