According to Sinolink Securities, due to the absence of a rotating mechanical structure, all the horizontal and vertical perspectives of laser detection are realized electronically, and because the assembly and debugging can be automated, it can be mass-produced, which greatly reduces the cost and improves the durability of the equipment, and solid-state lidar is an inevitable development route. At present, LiDAR mass producers are starting to develop LiDAR with better performance, smaller size, higher degree of integration, and lower cost, but the technical roadmap of solid-state LiDAR has not yet been finalized, and it is mainly divided into three categories: MEMS, OPA, and 3D Flash.
MEMS LiDAR
MEMS lidar replaces the traditional mechanical rotation device by integrating MEMS micro-galvanometers on silicon-based chips, and the laser reflected by the micro-galvanometers forms a wide scanning angle and a large scanning range. It has a wide range of applications in autonomous driving, robotics, industrial automation, and other fields. Compared with traditional mechanical lidar, MEMS lidar has the characteristics of small size, light weight, low cost and high durability. MEMS lidar controls the scanning of the laser beam through the fast and precise movement of the micromirror, achieving high-precision angle control and fast scanning, so as to obtain high-resolution scanning images.
Figure: Principles of MEMS LiDAR Technology (Source: Strange Knowledge)
According to Sinolink Securities, the advantage of MEMS lidar is that the MEMS micro-galvanometer is relatively mature, which can achieve solid-state laser scanning at a lower cost and higher accuracy, and can be scanned for objects that need to be identified and landed quickly.
Optical phased array OPA lidar
Optical phased array is an advanced light wave control technology that controls the direction of the beam by adjusting the phase difference of multiple emitting units, enabling fast scanning without mechanical parts. In the field of autonomous driving, OPA lidar is considered an ideal sensor because it can provide high-precision 3D imaging and environmental awareness. In addition, due to the ability of OPA lidar to provide high-resolution, high-speed, and high-reliability scanning, this scanning method is also considered to be one of the ultimate solutions for autonomous driving lidar in the future.
Figure: OPA LiDAR principle
3D Flash LiDAR
3D Flash LiDAR is a pure solid-state LiDAR technology that emits a large area of laser light covering the detection area in a short period of time, and then uses a highly sensitive receiver to complete the image of the surrounding environment. Compared to other types of lidar, Flash lidar does not have any scanning parts, so it is easier to pass the automotive specification, suitable for large-scale, cost-effective, and reliability applications.
Sinolink Securities comprehensively analyzed the three technical routes of MEMS, OPA and 3D Flash, and believed that due to the low cost of MEMS lidar and the low-cost mass production in a short time, the mass production of L3 autonomous vehicles may be dominated by MEMS lidar. In the mass production stage of L4 or above autonomous vehicles after 2022, it is possible that the sidelobe benefits of OPA or the human eye protection problem of 3D Flash will be solved to a greater extent, and there is a chance that MEMS will be replaced as a solid-state lidar with no moving parts.
After introducing the three types of solid-state lidar, the next article will analyze the development trend of solid-state lidar miniaturization, software, and ASIC integration.
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Development Trend of Multi-Sensor Fusion for Autonomous Driving (1)
