With the development of artificial intelligence, lidar has also received extensive attention. In the field of robotics, lidar can help robots understand surrounding map information in an unknown environment, provide good environmental awareness for subsequent positioning and navigation, and help robots achieve Smart walking.
What is Lidar?
Lidar is a sensor used to obtain precise location information, just like human eyes, which can determine the location and size of an object, and consists of a transmitting system, a receiving system, and information processing.
Its working principle is to send a detection signal (laser beam) to the target detection object, and then compare the signal (target echo) emitted by the target with the transmitted signal, and after appropriate processing, the relevant information of the target can be obtained, for example, the target Parameters such as distance, azimuth, height, speed, attitude, and even shape can be used to detect, track and identify targets.
Advantages of Lidar
Lidar works in the optical band, and the frequency is 2 to 3 orders of magnitude higher than that of microwave. Therefore, compared with microwave radar, lidar has extremely high range resolution, angular resolution and speed resolution.
Strong anti-interference ability
The laser has a short wavelength, can emit a laser beam with a very small divergence angle, has a small multipath effect (will not form a directional emission, and produce a multipath effect with microwave or millimeter waves), and can detect low altitude or ultra low altitude targets.
Unaffected by light
Lidar can perform detection tasks around the clock. It only needs to emit its own laser beam, and obtain target information by detecting the echo signal of the emitted laser beam.
Small size and light weight
Generally, the volume of ordinary microwave radar is huge, the mass of the whole system is recorded in tons, and the diameter of the optical antenna is several meters or even tens of meters. The lidar is much lighter and more dexterous, and the appearance is only centimeter-level. Moreover, the structure of the lidar is relatively simple, the maintenance is convenient, and the operation is easier.
Application of Lidar in Robotics
If the robot is allowed to recognize objects, walk, avoid obstacles, etc., it first needs to provide the robot with lidar technology to help the robot map, determine its own positioning and perceive the surrounding environment, and locate the surrounding objects. Take the sweeping robot as an example. The sweeping robot is currently the most widely used field of lidar. The lidar and SLAM algorithm can allow the sweeping robot to perform intelligent cleaning in the room, drawing the map during the cleaning process, and realizing the transmission to the mobile phone, even if the user If you are not at home, you can check the cleaning situation through your mobile phone and arrange cleaning in other places.
From the above figure, we can understand that in the field of robotics, China’s companies engaged in lidar include Xinda Technology, Silan Technology, Sagitar Technology, Hesai Technology, and many other well-known companies, basically focusing on the research and development of solid-state lidar. , And Xinda Technology is the first batch of manufacturers to make lidar, which has occupied more than 70% of the market share. In the research and development of lidar, Xinda Technology focuses on 2D graphic design, not only has made technical upgrades, but also worked hard. To achieve cost reduction, to a certain extent solve the problem of the use cost of navigation and positioning modules, and expand the application level. At present, the latest generation of RPLIDAR A3 lidar can achieve a 25-meter radius ranging, and the measurement frequency can achieve 16K/S, and it can be used indoors and outdoors.
Lidar has played an important role in helping robots walk intelligently. In addition to the robotics field, lidar is also widely used in many industries such as unmanned driving, AR/VR, and 3D printing.