Are laser radars used in robots? What function is it used for? Which companies in China are doing better?

Lidar is a radar system that emits laser beams to detect characteristics such as the position and speed of targets. In terms of working principle, there is no fundamental difference from microwave radar: a detection signal (laser beam) is emitted to the target, and then the received signal reflected back from the target (target echo) is compared with the transmitted signal, and after appropriate processing , relevant information about the target can be obtained, such as target distance, orientation, altitude, speed, attitude, and even shape parameters, so as to detect, track and identify aircraft, missiles and other targets.

But this article does not talk about aircraft missiles. This article mainly introduces the lidar on the car, commonly known as vehicle-mounted lidar. The vehicle-mounted lidar is also called a vehicle-mounted three-dimensional laser scanner, which is a mobile type. Three-dimensional laser scanning systems are currently one of the most effective tools for urban modeling.

What is a 3D laser scanner?

The three-dimensional laser scanner uses the characteristics of fast propagation speed and good linear shape of laser to emit the laser and receive the returned information to describe the surface shape of the physical being measured. Due to the different reflectivity of the measured object, the returned information received is also strong or weak. The so-called three-dimensional scanning uses the horizontal rotation of the scanner to cover an entire area. This process is very similar to folk 360-degree panoramic photography. The difference is that the "negative" we get is not an image but a surface shape composed of thousands of points, which is called a point cloud in measurement terms. Please see the hull of the ship on the right. It looks like a picture, but it is actually composed of countless laser points. Different colors are manifestations of different reflectivities returned by the laser.

Vehicle/ship-mounted lidar

Whether it is a vehicle-mounted, ship-mounted or even airborne lidar, the principle is to load a three-dimensional laser scanner and a POS system onto the vehicle. . The purpose is to establish DTM models in a longer and farther range. The purpose of GPS application is to let the car "know" its position at any time to facilitate fitting. .

In any mobile surveying system, the navigation system, which is the source of geographical coordinates given to point clouds and images, is a key component. Navigation systems generally use GPS and inertial navigation units. However, complex conditions on the ground, such as trees. Buildings and overpasses often block GPS signals.

Therefore, an advanced navigation system must include other auxiliary sensors and complete data processing methods so that the accuracy of its route can be guaranteed even when the GPS signal is lost