The second reason is the availability of cheap lidars, within the reach of anyone, yet with interesting specifications. Little by little, the possibility of using open-source software to control a lidar has come beyond the experimental stage.
Lidar, Arduino, Raspberry Pi, Laser, ToF and moreEven without being a specialist in the techniques used, the combination of a lidar, whether fixed, oscillating or rotating, with an Arduino (or a Raspberry Pi) will take you far in distance measuring or digitizing a space by echolocation. At the top end of the range of lidar’s possibilities, it can offer a precision of a few centimetres when mapping a large hilly surface. The range can extend to hundreds of kilometres for spatial systems. Among possible applications are 3D scanning of environments (for example architecture, cities, caves, archeology), real time telemetry for piloting ground-based or flying vehicles, speed control of vehicles (flash!) precision topography of earth or other bodies in the solar system, or even in forestry to observe the canopy.
Triangulation, phase detection, time of flight (ToF)
However, before attempting obstacle detection or distance measuring and mapping, we should familiarize ourselves with the notion of the various measurements, such as triangulation, phase measurement of the reflected wave, or even measurement of the ‘time of flight’ of the light. We should at least know how to use the sensors and software used for solving these problems.
And what better way to inform ourselves than several (short) well made videos?
In the first, a fixed lidar, mounted on an oscillating arm controlled by an Arduino, gives some amazing results.
In this sequence, a fixed TOF lidar measures distance in real time:
Here, a rotating YDLiDAR X4 lidar is used with the Google programme Cartographer for a spectacular mapping experience.
On his YouTube channel, the same author offers other applications of mapping with ROS, YDLIDAR X4 and a Raspberry pi 3 B+.
Within its range, the Elektor e-shop offers several new products with which you can carry out such hand-on experiments (see below).