Technically speaking, at present, traditional lidar technology is very mature, and solid-state lidar and hybrid solid-state lidar are still in their infancy. Therefore, the laser lidar used by companies in self-driving cars is mainly based on mechanical laser pointer radar. From the perspective of the entire lidar industry, manufacturers of high-precision automotive lidar products are mainly concentrated, such as Velodyne and Quanegy in the United States, and IBEO in Germany. In recent years, some companies focusing on automotive lidar have also appeared, and some companies Lidar companies, who have changed their fields, have devoted themselves to the research and development of automotive lidar products because of the broad development prospects of autonomous vehicles. At present, they have achieved remarkable results.
Like lidar, millimeter-wave radar is also a mainstream sensor used in ADAS systems for autonomous vehicles. Its wavelength is between centimeter wave and light wave, with short wavelength and frequency bandwidth. It has strong ability to penetrate fog, smoke and dust, can work around the clock, small and compact, and high recognition accuracy. It can help autonomous vehicles accurately ” “See” to the distance to nearby vehicles, so as to provide drivers with lane change assistance, autonomous speed control, collision warning and other help to improve driving comfort and reduce the incidence of accidents. And in terms of price, the unit price of millimeter-wave radar is far lower than that of lidar, which is a relatively easy to obtain sensor technology.
According to the current mainstream classification, automotive millimeter-wave radar frequencies mainly include two types of 77GHz and 24GHz. The former has a shorter wavelength and the green laser pointer has a longer detection distance, so it is mostly used for detection of vehicles in front; the latter is usually used for detection around vehicles , Such as blind spot detection. In addition, there are some millimeter-wave radars in other frequency bands, such as 60GHz in Japan and 79GHz used in Taiwan.