For LiDAR scanning solution Polygon Mirrors and Scanner Motors Vol.2

For LiDAR scanning solution Polygon Mirrors and Motors Vol.2


Chapter 5

Learn more about LiDAR

What is LiDAR?

We would like to pick up the LiDAR from among many sensors for autonomous driving vehicles.
The word “LiDAR” is an abbreviation for “Light Detection and Ranging”. It's an optical sensor technology that measures the distance to an object by irradiating an object with a laser beam while scanning it and measuring the time required for the object to bounce back, and identify the position and property of the object.

The development of LiDAR was originally utilized as a survey technique for measuring topography, buildings, forestry structures, etc. by loading it on artificial satellites and airplanes. Recently, small and light-weight LiDAR have also been developed, and they can be mounted on UAV (drone), which are unmanned airplanes, and surveyed to generate precise 3D mapping data.

In addition, LiDAR is expected to play an important role in the field of autonomous driving by utilizing its advanced visual recognition functions. LiDAR is used to create 3D mapping data and to recognize the surrounding environment (pedestrians, cars, etc.) required for autonomous driving.

Roles played by LiDAR in autonomous driving

Even if it is said to be an autonomous driving, level segments of automation are clearly defined.
The image of “Level-Cla​ssificatio​n​ of Automated Driving Systems” based on the SAE (Society of Automotive Engineers) announced from U.S. NHTSA (National Highway Traffic Safety Administration) is shown below for reference.

Up to Level 2 is a category of ADAS based on automatic braking, ACC (Adaptive Cruise Control) and LKAS (Lane Keep Assist System). Level 3 or higher is called the true autonomous driving level. Autonomous driving is advancing day by day, but in today's technology, the three sensors equipped in autonomous driving vehicles are mainly cameras, millimeter-wave radars and LiDAR.
Among them, LiDAR has excellent azimuth resolution, which makes it possible to accurately detect distances and positional relations with surrounding obstacles compared to cameras and millimeter-wave radars, and also to detect objects with low radio reflectivity (such as signs and trees) without difficulty. Therefore, LiDAR is positioned as an indispensable sensor technique for true practical automated driving that is worth more than the level 3 or 4 of the previous image.

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