Someone asked if the lidar, one of the important sensors in the autonomous driving era, can properly recognize this insensitive car.
As is known to all, lidar is an active imaging radar technology developed on the basis of laser ranging radar. It transmits and receives laser beams, analyzes the return time after the laser encounters the target object, and calculates the relative distance to the target object. The 3D coordinates, reflectance, and texture of a large number of dense points on the surface of the target collected during this process are used to quickly obtain the 3D model of the measured target and various related data such as lines, areas, and volumes to establish 3D points Point Cloud map, draws an environment map to achieve the purpose of environmental awareness.
When the emitted light is absorbed, the returning beam will be reduced, and the contour will not be clear enough when reflected on the lidar. Is this really the case?
In the video above, Ouster Lidar took one of their sensors to the X6 room and saw what they could see. In the end, the sensor looked for Vantablack, which is more extreme than ordinary black in all X6.
How Vantablack X6 was "discovered" by sensors
Generally speaking, sensors rely on reflected laser light and surrounding light to "see" objects, but when there are particularly dark objects, the reflectivity is very low. Mark Frichtl, co-founder and CTO of Ouster, explains why this extremely black color was captured by his company's lidar system this time.
Covering the XantablackVBx2 coating on the X6 greatly reduces the referability of the above two parameters (laser and ambient light). With a reflectance of 1% in the entire hemisphere, its reflectance is 10 times lower than a typical "low reflectance" scene. However, this low reflectance scene is already the largest range that can be monitored by lidar.
For a 10% reflective target, the maximum range of the OusterOS1-64 lidar sensor is 40 meters, so for a 1% reflective target, the maximum range is about 22 meters, such as vbx2 coated X6.
In other words, it does see the car, but it needs to be close to the car to really see the car. Fortunately, some parts of the car are highly reflective, so the Vantablack X6 is visible even when driving long distances.
"Some parts of the X6 are designed to be very reflective, such as the headlights, license plate and rearview mirror. These parts are easily visible from more than 100 meters away. As can be seen on the screen, the license plate is One of the brightest objects in the scene. "Of course, BMW will never sell Vantablack cars. But if someone decides to spend all their money on custom spray paint, that's fine. Because as long as the entire car (including the windshield) is not painted this black, the car can still be detected by the sensor.
Lidar can help vehicles see the road, especially the driver assistance function is very useful, so it has become one of the sensors of choice for most car manufacturers. In addition to adding redundant systems that already have cameras and radar, lidar can also create high-resolution images from light reflected from long distances, which allows vehicles to obtain more reliable target data.
This demonstration further proves that it is better to have a set of sensors on the vehicle than to have one sensor, and it can be more fully redundant.