What is lidar technology?

Most of today's advanced driver aids use a combination of radar and sonar to provide warning of invisible threats and help stop the vehicle before a collision occurs. Lidar is a technology that can perform similar functions to radar and sonar, but it is a next-generation system that may be the best option for the 'seeing' capabilities of AVs.

As automakers and other companies move into real-world testing and driving, it's clear that next-generation sensors and technologies offer compelling functionality.

What is Lidar?

Lidar is a 'light detection and ranging' technology (rough translation). The systems use lasers to map a three-dimensional model of the environment. Lidar's use of light allows it to map the environment more quickly and accurately than systems that use sound (sonar) or microwaves (radar). Lidar was developed by NASA to track satellites and distances in space but was picked up for use in other industries in the mid-1990s, when the US Geological Survey used lidar for tracking development of coastal vegetation.

Since then, technology has evolved and Lidar systems have become smaller and even more accurate. This has made Lidar an attractive option for adding 'eyes' to self-driving vehicles, as these vehicles need to quickly develop an image of the world around them to avoid hitting pedestrians , animals, obstacles and other vehicles.

Lidar systems map their environment by sending laser pulses outward. When the pulse comes into contact with an object or obstacle, it is reflected or bounced back to the lidar assembly. The system then receives the pulse and calculates the distance between it and the object, based on the time that has elapsed between sending the pulse and receiving the return beam.

Lidar does this quickly, with some emitting millions of pulses per second. As the beams return to the system, it begins to form a picture of what's going on in the world around the car, and can use computer algorithms to match shapes to the car, people and other obstacles.

How is Lidar used?

Radar has been used in the automotive world for many years and has been used in some forms of advanced driver assistance systems (ADAS). Blind spot monitoring uses radar to detect vehicles before changing lanes, adaptive cruise control uses radar to maintain a consistent distance between two vehicles on the road, and automatic emergency braking Dynamically uses radar to stop the vehicle before contacting an obstacle.

Lidar promises to improve on those features with more accurate environmental mapping and faster processing from the rapid nature of the system. Due to its 360-degree capabilities, Lidar will improve the accuracy and quality of safety warnings.

How Lidar works with AV

First, it's important to note that currently, autonomous or self-driving vehicles do not exist for sale to consumers. Vehicles like Tesla's or Cadillac's equipped with Super Cruise offer the ability to drive hands-free for extended periods, but do so only in extremely limited circumstances, such as on interstate highways.

As self-driving vehicles finally enter the world on a large scale, the amount of data needed and the speed at which it is collected is staggering. To incorporate a decision-making process anywhere remotely close to the level of complexity that the human brain can manage, autonomous vehicles need to have an accurate and real-time picture of Around the world. This is especially true in urban environments, where drivers encounter other people, animals, and a variety of vehicles within a short period of time.

Disadvantages of Lidar

Lidar is considered the standard for many companies working on autonomous vehicles, but the technology has not been fully adopted by all automakers . Tesla and its founder Elon Musk have criticized Lidar as the driving force behind AV awareness, because the technology only recreates an image of the surrounding environment rather than a representation of what is going on. .

An example of this is with small obstacles on the road. Lidar is more than capable of determining that there's something on the road that needs to be avoided, but it can't tell exactly what it's looking at. To lidar, a balloon hovering in the middle of the road looks exactly like a large rock, so there are times when a threat is not one to be taken seriously and times when a real threat may not be. recognized as such. In a vacuum, this isn't a big deal, but in the real world, it's not ideal for a vehicle to misunderstand what it's looking at.

Tesla argues, as do others, that using a vision-based system with cameras can achieve the same perception that lidar systems provide, but with the additional level of security that comes from images of realistic environment. Tesla's systems use cameras and learn over time, which makes them better able to deal with unpredictable environments. That functionality, combined with the fact that cameras are now much cheaper than lidar cameras, has led some to question the need for expensive sensors.

The answer to which sensor or camera would be best for autonomous vehicles is more complex than determining whether a car can 'see' or not. The tests that are still being conducted to date have largely been carried out in limited and somewhat controlled environments, which are not entirely representative of the conditions that AVs might see on a daily basis.