‘LiDAR’ and ‘RaDAR’ Technology: Autonomous Vehicles
In this fast paced world of automotive development, staying ahead requires knowledge to cutting-edge tools and technologies. ‘LiDAR’ and ‘RaDAR’ are such technologies widely used for navigational purpose in autonomous vehicles. In this article we shall explore how these technologies work by looking at their working principle, their benefits and use cases in different scenarios.
So, without taking any time let us deep dive into understanding the following concepts!
LiDAR (Light Detection And Ranging)
LiDAR (light detection and ranging) is a light-based remote sensing technology which uses light (eye-safe laser beams) to visualize the world in 3D, providing computer or ECU an accurate representation of the surrounding environment.
How does LiDAR works?
LiDAR basically works on principle of reflection of light, the idea behind is quite simple: The LiDAR sensor emits pulsed light waves into the surrounding environment, which is reflected off the objects and returned to the sensor, the sensor then uses the time it took for each pulse to return to the sensor to calculate the distance it traveled. Based upon the distance travelled and intensity of light received back a point on the 3D map is created by the ECU.
Repeating this process millions of times per second creates a precise, real-time 3D map of the environment. This 3D map is called a point cloud. An onboard computer can utilize the lidar point cloud for safe navigation.
RaDAR (Radio Detection And Ranging)
RaDAR (radio detection and ranging) works on the same principle as LiDAR with a big difference that it uses radio waves instead of laser or light.
How does RaDAR works?
Radio waves are transmitted from the sensor in the direction of interest which are bounced back and return back to sensor by objects in the surrounding. The sensor then compares the characteristics of these reflected waves against the transmitted waves to infer the position, distance and movement of nearby objects.
Use cases of ‘LiDAR’ and ‘RaDAR’
So, now since we know how LiDAR and RaDAR technology works the question is what are the use cases of both? How both differ from each other apart from the types of wave they use? In which scenario LiDAR is useful and in which case we should go for RaDAR techonology? Can both be used together? Why to go for LiDAR and RaDAR when we have on-board camera systems available for object detection?
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The following paragraph will answer these questions.
When is LiDAR useful?
LiDAR is usually preferred for tasks requiring meticulous mapping and object recognition in close environment such as road lanes, market areas and busy streets, as LiDAR is better able to perform accurate 3D mapping, obstacle detection, and environmental monitoring as compared to RaDAR by having lateral resolution of just few centimeters.
When is RaDAR useful?
Although RaDAR may not provide as much detail as LiDAR, it still has a number of advantages that make it a great candidate for navigation in autonomous vehicles. One reason is that, in contrast to LiDAR, Radar is less impacted by weather conditions like fog, rain, or snow as radio waves has high capability to travel longer distances owing to their higher wavelength but their lateral resolution is limited by the size of the antenna which is of several meters whereas LiDAR provides more compact solution. Therefore, RaDAR find its important application in air traffic control and radar astronomy.
Limitation of Camera systems?
Cameras are limited to only capture the environment which is in range of visible human eye whereas LiDAR and RaDAR provides more detailed information about surroundings with highed range to allow autonomous vehicle to detect and avoid obstacles more accurately even at high speed. Moreover, lidar systems work in any lighting condition giving them an advantage over cameras, which need light to be able to perceive their surroundings.
Can LiDAR and RaDAR be used together in autonomous vehicles?
Yes, today autonomous vehicles are not limited to only one type of technological solution and have become a complex system of interconnected sensors. ‘LiDAR’ and ‘RaDAR’ systems are used together along with camera systems to improve navigational capability of the autonomous vehicle for safer navigation, and better functionality in poor lighting or weather conditions.
To sum up, LiDAR, RaDAR and Camera systems are some of the necessary and complex technologies important for vision and navigation. Although each of them differ fundamentally but combination of them is essential for creating safe and successful self-driving vehicles.
Hope it was a good read and you gained good knowledge from this story. Thankyou!
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