The number of lines determines the resolution of the lidar. The laser pointer radar works in a rotating scan mode. One light source is swept around to get a 360-degree horizontal circular line of sight. This is why the "big flower pot" on the roof of the unmanned car has to rotate constantly. The more light sources, the denser the line of sight, and the higher the resolution of the real-time map. Zhang Zhiwu uses the analogy of sketches: Sketches are composed of lines. The denser the lines, the clearer the painting.
The earliest domestic 16-line products were launched in 2016 and currently have a maximum of 40 lines. To manufacture multi-line number of lidars, domestic manufacturers generally face the problem of complicated processes. Increasing the number of lidar lines in the traditional way is like splicing radiators that are getting wider and wider, causing the product volume to be doubled and greatly increasing the difficulty of mass production. According to Jin Yuanhao, CEO of Lidar Technology Co., Ltd .: "In the current process conditions, increasing the number of lines requires increasing the number of printed circuit boards, and the volume of lidar will also increase significantly. The scale and integration must be taken into account.
The reason why foreign manufacturers can make 64 or 128-line laser pointers is that the chip of the internal components plays a decisive role: reducing the size of the lidar, reducing heat dissipation, and helping mass production.
This requires special chips with large capacity, fast transmission speed, and efficient information processing. At present, domestic laser radar companies generally purchase German osram transmitters. In response, Huang Wuling, a domestic expert in smart car research, emphasized that "core chips, especially transmitters and detectors, need to be improved in terms of localization and anti-interference."
Unlike mobile phone chips, receiver chips do not pursue the largest number of transistors per unit area, but have higher requirements for resolution. The original demand was small, tens of thousands of tablets a year. In the past two years, the air outlet suddenly turned to high-resolution high-quality laser pointer sensors. "The reception of laser signals has a high level of integration. Originally, it was a 1 × 1 single-point sensor. Nowadays, cars require high resolution, which is 1064 × 768." Jin Yuanhao said. Production of products with this resolution according to an independent process is about the same size as a half of a car's front windshield, which is unrealistic to use. Therefore, domestic products are starting to catch up with chips with less resolution.