For autonomous vehicles that will operate in the city, driving at night means that they will most likely have light to drive by. Anyone who has ever driven in a rural area with no streetlights on a night with little or no moonlight knows just how dark it can get. To help autonomous cars operate safely Ford’s Fusion Hybrid autonomous research vehicle has LiDAR sensors that allow it to see in the dark.
In fact, the LiDAR sensors can see in the dark so well that the autonomous research vehicle can drive without its headlights on. This research is important because it is able to show that even when the cameras the autonomous car uses to see the environment lack the light they need to operate, the LiDAR sensors allow the car to operate safely.
“Thanks to LiDAR, the test cars aren’t reliant on the sun shining, nor cameras detecting painted white lines on the asphalt,” says Jim McBride, Ford technical leader for autonomous vehicles. “In fact, LiDAR allows autonomous cars to drive just as well in the dark as they do in the light of day.”
Ford autonomous cars use high-resolution 3D maps with information on the road, road markings, geography, topography and landmarks like signs, buildings, and trees. LiDAR pulses are able to tell the car exactly where it is on those maps. The LiDAR sensors in use produce about 2.8 million laser pulses per second. Test engineers monitored the car from inside and out using night vision goggles that allows them to see the infrared laser beams that the LiDAR sensors produce.
“Inside the car, I could feel it moving, but when I looked out the window, I only saw darkness,” describes Wayne Williams, a Ford research scientist and engineer. “As I rode in the back seat, I was following the car’s progression in real time using computer monitoring. Sure enough, it stayed precisely on track along those winding roads.”