Sensor Testing in Adverse Visibility Conditions

Purpose and goal

There are several adverse weather conditions to consider but this project is limited to road spray as it causes severe visibility impairment and differs from rain by smaller droplet size and higher drop distribution. The project aims to collect data on the properties of water spray and the influence of light and wind. By the end of the project, AstaZero should have built equipment to test vehicle sensors that also can be used in the future to validate different types of spray models. Repeatability of the spray will be in focus and emulated spray should also be as real as possible.

Expected results and effects

The project has developed a rig to create well-defined, life-like water spray in a repeatable way. In addition to the equipment, a measurement and analysis method for the evaluation of contrast degradation caused by water spray has also been developed. With this method, the project has been able to repeatably lower the contrast from 1 down to 0 and keep it within a +-5% range. The direct effects of these results are continued research in the field as well as opportunities for more collaborations with the industry to accelerate development towards higher sensor availability in bad weather

Planned approach and implementation

The project has carried out measurements and data collection on real spray by drivingon the test track, as well as spray generated with a rig both outdoors and indoors. For measuring contrast, black-and-white checkered targets have been filmed with a camera and analyzed with a software tool that was also developed in the project. This tool has also been used to calibrate camera settings to better handle varying lighting conditions. The target was first filmed without spray and the measured contrast was then compared to that with different amounts of spray applied in front of the target.