Lidar is the most indispensable part of all sensors that are related to the automatic driving vision system. Affected by the continued fire of the global automatic driving field, the track is now becoming crowded, with the Velodyne's LiDar R & D capability and mass production strength to hold the "one brother" position, and then Quanergy, LeddarTech, and rapid development, and so on. The auto driving giants such as Baidu, Ford and Ann FOK continue to fan the flames, and the laser radar is bustling.
At the same time, with the continuous friction and collision between the old and new technology, the laser radar "Eighteen Rohan" has also started to set up different technological camps to pry the entire automatic driving "river and lake". Among them, the four main groups of laser radar battlefields have been set up by the mechanical rotation scanning of Velodyne, the representative of the MEMS, the Quanergy representative and the 3D Flash represented by LeddarTech. In addition, new technologies such as FM linear frequency modulation of Strobe, COR coherent light of Oryx Vision and the solid-state array of optical perber intelligent are also beginning to emerge, and become an innovative force to break the traditional laser radar technology.
1. Mechanical rotation scanning camp
In all kinds of laser radars, mechanical rotation scanning LiDar is the founder and the first blood path leading to the automatic driving battlefield under the guidance of "Jiang Hu one brother" Velodyne. Besides Velodyne, Quanergy, Ouster, Ibeo and domestic race technology are also working on the market of mechanical rotating scanning lidar. With the continuous refinement of the technology, more and more high line bundles (such as 128 line) LiDar products are also formally joined to the battlefield via the hands of Velodyne, and Velodyne is also carved in one stone to further consolidate the dominant position of its own industry, and the mechanical rotation scanning LiDar is still under the large-scale impact of the new solid laser radar technology. Be able to keep the initiative.
However, as far as long-term development and commercialization are concerned, the design principle and structure have tended to be fixed because of the use of many mechanical components in this type of product. The high price and average failure time is only 1000-3000 hours, which is difficult to reach the minimum requirement of 13000 hours. As a result, the market for multiparty application bottlenecks, the market for mechanical rotating scanning laser radar is not expected by car factories and technology developers, which has also made the Quanergy and Ibeo companies, which had been continuously ploughed in the field, began to switch to mixed solid-state and solid state laser radar product routes.
2, MEMS camp
Compared with the traditional mechanical multi line lidar, the MEMS type scanning using micro galvanometer scheme can greatly reduce the use of transmitters and receivers. This design can reduce the number of parts and components rapidly, and the cost of the corresponding parts can be reduced greatly. At the same time, it can be formed once, which greatly reduces the development cost of LiDar and improves the production capacity.
In addition, because it can be made into solid-state lidar, it is easier to achieve scale and commercialization. In recent years, it has been popular among more and more international manufacturers. At present, the development of MEMS lidar mainly includes Luminar, Innovusion, Innoviz in Israel and domestic manufacturers such as Sagitar. Although the products of American company Cepton have a part of MEMS, the company's laser radar is mainly implemented by micro motion technology, not pure MEMS LiDar technology.
3. Phased array camp
The phased array technology was originally derived from military radar, and a row of launchers carried by this kind of laser radar can change the direction of the laser beam by adjusting the relative phase of the signal. There is no mechanical action in the whole process, and the scanning is realized only by the electronic component itself. But on the whole, the technical threshold of the phased array is the most difficult one of the three solid state laser radar schemes, and the development cost is very high. At present, the enterprises that can truly realize the breakthrough are less, and the manufacturers are mostly in the stage of technical exploration.
In this route, Quanergy is a leading manufacturer of them, in addition to the Leishen intelligent domestic and Sagitar juchuang. As a matter of fact, there is no clear product development route in the industry, and there are various tricks of the family. For example, the leader of the field, Quanergy, mainly controls the production of the laser beam and the process of scanning. It only needs to adjust the density of the point cloud in different regions of the field of vision, so that the precision of the phased array radar can be controlled. Degree. Similar to MEMS, with the further deepening of the laser radar to the solid-state direction, the R & D route of phased array has also begun to rise rapidly in the field of laser radar in recent years, and has become a major backbone in the solid state laser radar camp.
4, 3D Flash camp
Compared with MEMS and phased array two solid-state laser radars, the 3D Flash laser radar is more like a camera. It is a non scanning laser radar product. The laser beam will diffuse directly to all directions and collect the reflected laser beam from the CMOS sensor similar to the camera imaging. It can record the whole scene quickly, and the difficulty is also the sensor to receive the signal. So at present, it is inferior to the first three kinds of performance. At present, the representative companies of Flash camp laser radar products are mainly LeddarTech, TetraVue, and domestic North awakening photons and North Ke Tian paint manufacturers.
5, other innovative camps
Linear frequency modulation FM
Since Strobe was bought by GM, FM LiDAR has been widely concerned by the industry. The laser radar mainly launches the LFM laser, and only needs to measure the phase and frequency of the return laser, and the system can directly obtain the distance and speed of the object around the vehicle. This greatly reduces the computational load of the vehicle brain, making it able to make decisions faster.
In addition, more advantages of FM LiDAR are stronger anti-interference ability, no sensitive photoelectric detectors, only the "echo wall mode" optical resonator can reduce the line width of the laser and bring more accurate signals, and the light from the resonator will return to the exciting light source, but the line width will be narrowed and then only need to be adjusted. With the optical characteristics of the whole resonator, a highly linear FM laser can be obtained, which meets the needs of the self driving vehicle. Cruise Automation's CEO Kyle Vogt also said that the size of a Strobe LFM can reach a size of 25 cents, and can reduce the cost of a laser radar by 99%, but the authenticity remains to be tested.
COR coherent light
The COR coherent optical product comes from the Israel Corp's Oryx Vision, which uses the technology called "nano antenna" to receive electromagnetic waves, thus obtaining more additional information. The advantage of this technology is to increase the scope and sensitivity of the auto driving car to the outside world, so that it has a clearer understanding of the surrounding environment and what is happening. The Oryx antenna can receive electromagnetic waves with a wavelength of 10 microns, so it can penetrate smog effectively, and it will not be affected by strong light like lidar.
In addition, Oryx's COR coherent optical LiDar does not have any movable components. The nano antenna technology is used instead of the photodetector, and the distance and speed information of the light points are obtained in the high resolution scanning of the surrounding environment. Moreover, the laser is a long wave terahertz infrared laser, which is invisible to the eye of the infrared light, so the COR coherent light LiDar system can achieve higher power than the ordinary laser radar.
Solid surface formation
The representative manufacturer of the solid surface formation is the domestic optical perber intelligence. The technical route is to pass the pulse laser through the homogenization device and illuminate the detection direction in accordance with the design angle. The backward scattering pulse laser is imaging on the surface array sensor through a special lens. Each pixel on the sensor can be detected by the laser echo, and the system can get the distance of the corresponding point by calculating the time of flight.
In design, the structure of this scheme is relatively simple, and it can be automated large-scale production. In terms of performance, the solid-state array scheme can achieve high spatial resolution. The array laser radar can increase the vertical resolution to an order of magnitude compared to the 64 line laser radar. It can not only determine the relative position of the obstacles, but also identify its properties, and avoid the bottleneck of the application of many traditional mechanical laser radars.
Hangzhou Smart Lidar Technology Co.,Ltd.
Contact:Mr Li
Phone:+86-13989489625
Tel:+86-571-28205716
E-mail:sales@smart-lidar.com
Address:Rm. 5A02, Bldg. T3, ChangHe Rd. 475, Binjiang Dist.Hangzhou 310052, China