Lidar is an indispensable laser pointer sensor for autonomous driving. The system framework of the partial algorithm layer for unmanned driving. The acquisition of high-precision maps relies heavily on lidar and cameras. After obtaining high-precision maps, we combined GPS and IMU, encoders, and real-time perception of the environment to perform map matching and positioning. For path planning and motion control, the vehicle’s CAN bus is ultimately used to control the vehicle.
In terms of perception, we generally use lidar, camera, and millimeter-wave radar as sensors for sensing external objects. Among them, lidar can do object recognition, classification and tracking, and the camera can also do object classification and tracking. Millimeter wave radar is mainly used for object obstacle recognition. The three sensors, millimeter wave radar, camera and lidar, have some overlapping points. This is determined by the nature of the sensors themselves, they have their own indispensable functions.
Millimeter-wave radar is mainly used for obstacle detection; it is difficult for the camera to obtain a three-dimensional object model, including its interference to the environment. It also depends on the influence of this illumination, but the camera is very good at classifying and tracking objects; lidar is generally used For positioning, obstacle detection, object classification, dynamic object tracking and other applications. In fact, before that, the development of the lidar industry was relatively slow. But now, including the urgent needs of upstream suppliers and downstream customers, we strongly hope to promote the realization of cost reduction and mass production of lidar.
Lidar is currently divided into two categories: scanning lidar and non-scanning lidar. The mechanical rotating lidar (transmitting, receiving, and coaxial rotating lidar) is currently relatively mature, and more programs are used for unmanned driving downstream. The more representative ones are Velodyen and Ibeo, including the mechanical lidar that we are currently in mass production. The hybrid solid state is also a mechanically rotating red laser pointer radar. The other is MEMS. The MEMS-based scanning radar is currently in the research state, and its principle is to change the optical path through the MEMS scanning mirror.
There is also a phased array laser radar (OPA), which is actually a scanning laser radar, because it is achieved by changing the optical path through the point-by-point scanning method, that is, the phase of the laser emitted between multiple small antennas .