In recent years, electromagnetic sensors like Radar are mostly used in cars especially in adaptive cruise control systems. It is regarded as a robust and inexpensive technology. Distances and speeds can be measured by enabling Radar but with the problem of detecting non-metallic obstacles like an animal, and human beings.
It has the ability to detect cheap short-range radar up to 30 meters and the expensive systems can measure a distance with a long-range up to 250 meters.
Mostly, the Radar up to 30 meters can be used as cross-traffic alarms for parking and entry sensors whereas the long-range of 250 meters can be for controlling distance on the motorway or in emergency braking systems.
LIDAR works on the same principle of electromagnetic operation but with optical where light beams are emitted by the sensor that can calculate object distance from its travel time.
The technology is mainly used in emergency brake assistant systems within the city for detecting obstacles to provide a reliable result at a relatively lower cost.
Compare to Radar, people can be detected better by LIDAR. The laser scanner has been considered as the most potential technological developed product from the next stage.
The LIDAR is of a special form with a rotating mirror to observe a 360-degree environment with a high resolution and a greater distance. It is indispensable and the technology is found only in prototype vehicles which are expensive.
Even then, large automotive suppliers like Continental and Bosch entered the business which was founded by start-ups only so the costs can fall in the future.
Source:- Commercial Vehicle Technology 2018 by Karsten Berns et al.