How Lidar Works — and Why It’s an Essential Component of Autonomous Vehicles

Lidar is necessary for all levels of automation — and it’s the one piece of hardware which most of those in the race to build the best autonomous vehicles deem essential.

In this post, you will learn more about Lidar technology, how it works and the way it has impacted the development of self-driving cars. Keep on reading.

What Is Lidar? An Introduction

At its core, Light Detection and Ranging (LIDAR for short) is a remote sensing technology which is used to measure distances. One of Lidar’s predecessors is radar, but unlike radar which sends out radio waves, it emits pulses of infrared light to detect objects.

The Lidar sensor utilizes the same eye-safe lasers as the standard barcode readers you’ve seen cashiers use time and time again.

However, the Lidar laser emits billions of pulses per second at 360 degrees. This is meant to provide a complete, all-around image of the surrounding world.

Lidar technology has many uses, including scanning and real-time mapping — both of which serve autonomous vehicles. The next paragraph will focus on how Lidar operates on top of a self-driving car, so keep on reading.

Understanding the Basics of How Lidar Works

Those spinny things on top of self-driving cars might look kind of silly, but they are quite remarkable.

In a nutshell, here’s how they work: pulses of light are emitted from the lasers which spin in circle. When they hit an object such as a tree, they bounce back to the Lidar sensor.

Distance is measured based on how long it takes the pulses of infrared light to travel back.

The results are then compiled into a point cloud, which can be defined as a set of data points in space.

This happens millions of times per minute, which means millions of data points and calculations are taking place at incredible speed. The result is a constantly-updated map of the world around the car.

This map is so detailed it can be used to safely guide autonomous vehicles on the road — which makes it extremely useful.

The remarkable thing about Lidar is it functions almost instantaneously for both stationary and moving objects. In other words, it showcases movements and works for moving pedestrians, bicyclists and other vehicles in traffic.

What’s more, compared to most of today’s radars, Lidar is far more target selective and more precise.

2 Ways in Which Autonomous Vehicles Rely on Lidar Technology

1. Lidar Provides an Incredibly-Detailed 3D Representation of the Car’s Surroundings

It’s true autonomous vehicles use other sensors to “see” their surroundings — most commonly cameras and radar. However, these often fall short when compared to Lidar’s precise laser vision.

As opposed to cameras which provide a 2D vision, flat image of the environment, Lidar showcases a 3D representation of its surroundings.

A self-driving car needs to safely travel at speeds of over 50 miles and make decisions every second, constantly adjusting for new data coming in from the environment.

So you can see why Lidar technology, which can reveal the world around the car in startling detail, is crucial.

What’s more:

• Lidar significantly reduces blind spots and wide-angle hazards thanks to its 360 degrees view and extended sensor range of up to 300 meters. Not only that, but it also has enough range resolution to accurately know what is going on around it.
• As opposed to cameras which sometimes struggle in the dark, Lidar technology is effective in low-visibility, nighttime conditions as well because it is its own source of light.
• Lidar can detect the intensity of the laser beam returning to its receives, which means it can measure brightness. As a result, it can pick out on shiny items such as lane lines and even letters on signs or other vehicles.

2. Lidar Plays an Essential Role in a Car’s Ability to Understand the Environment

Lidar not only acts as the eyes of the car, but also as part of its mechanism to make accurate, split-second decisions — a critical requirement of autonomous vehicles operating safely in real-life road conditions.

And to make accurate decisions, a car has to have a precise understanding of its environment. For instance, it must discern a paper bag flowing in the wind from a small child running towards the car.

One of the aspects which makes Lidar so valuable is it not only highlights objects, but makes them recognizable as well by offering computer-friendly data in the form of exact measurements.

And once a car’s computer has the data it needs to identify objects, it can predict how those objects will behave and thus how it should adjust its driving (break/change lanes to avoid impact if it’s a child, maintain course if it’s only a paper bag).

We’re not quite there yet.

Lidar is considered to be a somewhat immature technology, which means there is still a lot that needs to be figured to make Lidar a viable product for the autonomous vehicle industry which is beneficial at scale.

Now You Know

I hope this article has helped you grasp a better understanding of how Lidar works and why it’s a vital part of autonomous cars being a reality everybody can enjoy without compromising safety.

As things stand now, Lidar technology is still expensive and would increase the price of a self-driving car with at least $4,000. But its potential to advance roadway safety for cars which don’t need a steering wheel, prevent crashes and save lives is undeniable.

So it’s no surprise the leading players in the self-driving car race are investing top dollars in developing their own versions of Lidar in-house.

This increased interest for Lidar translates into exciting things for the future of the self-driving car.

For that, look forward to the second part of this Lidar series in which I’ll go into more details about solid-state Lidar and how it can help tomorrow’s autonomous vehicles push things even further.

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