What is the use of automotive LiDAR?

The difference between LiDAR and millimeter-wave radar

LiDAR is a radar system that emits light beams to detect the position and speed of the target. It is equivalent to our eyes, with powerful and complex information perception and processing capabilities. Excited light radar has been widely used in aircraft obstacle avoidance, reconnaissance imaging, missile guidance, and other fields many years ago, and its application scenarios are extremely rich.

Automotive laser radar is mainly used for autonomous driving, which is the future of unmanned driving. However, it is currently only used for autonomous driving assistance. LiDAR is mainly based on multi-wire beams in automobiles, which can help the automobile perceive the road environment, plan the driving route by itself, and control the vehicle to reach the predetermined goal. For example, the relative distance between the target and itself can be calculated according to the turn-back time after the laser encounters an obstacle, which can help the vehicle identify the intersection and direction.

The difference between LiDAR and millimeter-wave radar is that LiDAR uses the laser as the detection method, while millimeter-wave radar uses millimeter wave as the detection method; the wavelength of millimeter wave is at the millimeter level, and the laser is essentially an electromagnetic wave, but the wavelength is too small Many, in the order of a few hundred nanometers, which is about one thousandth to one ten thousandth of a millimeter wave.

In addition, from the actual effect, the point cloud data obtained by the LiDAR can be recognized by AI after processing, and the type of obstacle can be accurately determined, whether it is a person or a dog, a car or a tree, and then it can be more intelligent for automatic driving according to the type of obstacle. The system serves as the basis for judgment.

The detection accuracy of millimeter waves is much lower. It can only determine the general shape and distance of obstacles, and cannot be used to obtain more accurate contour and three-dimensional shape information. Millimeter-wave radars have been widely installed in L1 and L2 autonomous driving assistance systems. For example, the function of auto-following cars, many of which use meter-wave radar.

For example, Tesla is good at combining mature and low-cost technologies to implement complex functions through his software. Now, it mainly uses a combination of cameras and millimeter-wave radar to provide real-time road condition input required for autonomous driving.