Compared with microwave radars, which have the same application in the car, the laser radar working in the optical band has a higher distance resolution, angular resolution and speed resolution than the microwave level of 2-3 orders of magnitude. Therefore, the lidar in the measurement process can bring distance, angle, reflection intensity, speed and other richer information, with these data can generate multi-dimensional target images, to help us or the system has a more detailed awareness of the target.

In addition, due to the short laser wavelength, can launch a very small divergence angle (μ rad order) of the blue laser pointer beam, multi-path effect is small, that is not formed directional emissions, and microwave or millimeter wave generated multipath effects, anti- To achieve low altitude, low altitude target detection. The laser active detection has a characteristic that does not depend on the external lighting conditions or the radiation of the target itself. It is only necessary to obtain the target information by detecting the echo signal of the laser beam emitted by itself, so that all-weather work can be realized. However, the laser radar is susceptible to atmospheric conditions and the dust of the working environment, to achieve the all-weather working environment in the present terms or the most difficult thing.

In fact, the premise of laser radar technology is 3000mw laser pointer ranging technology. We can usually see the distance measurement method, from the categories can be divided into: laser time-of-flight method and triangular method. In simple terms, they are suitable for long distance ranging and short distance ranging. The TOF method can be divided into: pulse modulation (pulse ranging technology), the use of the target to the optical signal diffuse to measure distance; phase modulation, the intensity of the laser continuous wave modulation, by the phase difference to measure the distance information The The choice of LIDAR for different methods depends largely on its type and practical application.

Lidder is also divided into many categories. Starting from the modulation, there are mainly direct detection of lidar and coherent detection of lidar. Commonly used, including autopilot, robot, mapping used, is basically a direct probe lidar. More special, such as wind, speed and the like radar, the general use of coherent modulation. If you start from the application, that classification is more, such as laser range finder, 5000mw laser pointer three-dimensional imaging radar, laser radar, laser detection radar and so on. Among them, the laser three-dimensional imaging radar contains our well-known laser mapping, as well as automatic driving in the single-line laser radar and multi-line laser radar.

In the current automatic driving, there are single-line laser radar and multi-line laser radar points. Due to the high sampling frequency required in the application, triangulation and pulse ranging are used in close and long distance measurements, respectively. Among them, the single-line laser radar mainly through a high frequency pulse burning laser pointer range finder, plus a one-dimensional rotation scan to achieve the measurement. And its angular resolution can be higher than the multi-line laser radar, so pedestrian detection, obstacle detection (small target detection) and the front of the obstacle detection and so on, than the multi-line laser radar has more advantages. Multi-line program is also mainly for multi-channel single-line collection, which is also subject to volume and optical path restrictions.

First of all, the laser radar is used in infrared laser, this laser itself in the infrared band radiation is much lower than the visible light. Furthermore, the application will use a very narrow filter, directly to the strong background light filter, and then use infrared light to detect. So that we can get a high-quality lane line image, through the image of the gray, you can easily detect the lane line. In general, with a 20000mw laser pointer radar to do lane line detection, performance will be better than the camera.