LIDAR, lasers, and logic: Anatomy of an autonomous vehicle

Autonomous vehicle LIDAR roofAutonomous vehicles are getting a lot attention as of late, and if this last CES prophesized anything, it’s that this tech trend has some serious mileage. With companies like Audi, Lexus, and Google exploring ways to push the driving experience into the 21st century, we’re not far from a future where driving is done by machine – not man. But before you can rush out to your local dealer (just kidding; none of these are at your local dealer) to catch a glimpse of our automated overlords, you’re going to notice one striking similarity across virtually all models: the LIDAR. We know what you’re thinking: The what-DAR?

Frikkin lasers

One of the most integral, expensive, and noticeable pieces of equipment found in an autonomous vehicle is the roof-mounted, Death Star-like LIDAR sensor. LIDAR, which stands for Light Detection and Ranging, is a remote-sensing technology that measures and maps the distance to targets, as well as other property characteristics of objects in its path. LIDAR essentially maps its surroundings by illuminating its targets with laser light and then analyzing that light to create a high resolution digital image.

While LIDAR sensors are employed in virtually all autonomous research vehicles, the technology has already featured in cars with adaptive cruise control systems (ACC).

In vehicles with ACC, a LIDAR device mounted on the front of the vehicle, like the bumper, is used to monitor the distance between that vehicle and any car in front of it. If the vehicle in front slows down or gets too close, ACC independently applies the brakes to slow the vehicle down. When road conditions open up, ACC allows a vehicle to accelerate to a speed preset by the driver. Refer to my review of the 2013 Mercedes SL550 for an example of a vehicle with adaptive cruise control.

Roof-mounted LIDAR sensors function a little differently, however, and behave similarly to what you’d see atop a satellite installation on an airfield or aboard a small fishing vessel.

Here we have a low-spinning dish (say 1 rpm) gathering long range, low resolution targeting of other objects (other vessels or aircraft for example). This low-res feedback may work for stationary installations, but vehicles need much higher resolution imagery and at much closer range.

Lexus LIDAR autonomous vehicle

While not official figures, the rpm count on, say, Lexus’s AASRV vehicle, shown at CES, might spin at 600 rpms. This increase in rpms allows the vehicle to map its surroundings with greater detail, speed (less than a dozen milliseconds), and accuracy, which is essential on a roadway where conditions are constantly changing.

Currently, LIDAR sensors are not built in-house, but they are commercially available – and expensive. Oh so very expensive. A top-of-the-line Velodyne sensor, for example, can fetch $70,000 a pop and can be found hypnotically spinning atop Google’s, Lexus’, and Audi’s research vehicles.

Roadmap to autonomy

LIDAR might be the most conspicuous piece of driverless tech, but as Paul Williamsen, Global Manager of Education and Training for Lexus International, tells me, the anatomy of autonomous vehicles, including LIDAR, encompasses four relatively broad domains:

  • Making a vehicle in which you can control the steering, the power delivery, and the breaking – all automatically.
  • Technology that allows the vehicle to sense the environment around it
  • The processing – what does that vehicle determine, what decisions does it make based on the sensing of what is going on around it
  • The output – what actions does the vehicle make based on that processing

The wave of the future

In addition to LIDAR providing sensory feedback, autonomous vehicles employ a not-so-new technology called millimeter-wave radar, which involves various infrared and optical sensors placed at the front of, sides, and rear quarters of a vehicle.

As you’ll no doubt recall from high-school science class, millimeter-wave radar emits extremely high frequency (short) wavelengths, which is ideal for detecting objects (cars, pedestrians, and large animals) in a vehicle’s immediate vicinity.

Mercedes SL 550 LIDARInfrared and optical sensors already feature heavily in current Audi, Lexus, Acura, Subaru, and Mercedes vehicles. Lexus’ 2013 LS 460, for example, sports what is called an Advanced Pre-Collision System (A-PCS). This works in conjunction with millimeter-wave radar, front facing near infrared projectors, and a front-mounted stereo camera. Essentially, A-PCS is designed to avoid low-speed collisions by scanning vehicles in the near-to-far vicinity, determining potential collisions, and emitting audio visual indicators if a danger is present, and eventually operating autonomously by applying emergency braking countermeasures.

As you can see, autonomous vehicle technology is a mixture of sensing and processing protocols. While millimeter wave radar sensors can be placed in and around the vehicle, such examples, like the ones seen on both Google and Lexus prototypes, typically feature even more sensors hung from brackets off a vehicle’s bumpers. These allow for even greater radar sensing to the sides of the vehicle, as opposed to just the front. This way, information can be gathered accurately in adjacent lanes, cross-streets and intersections.

The brains of the bunch

Of course, all this information needs to be collected and processed, which is why autonomous vehicles now and in the future will make use of relatively powerful onboard computers. As Lexus’ Paul Williamsen explains, “The vehicle we showed at CES actually has a number of high-powered computers in the trunk of the car, computers that you and I might have on your desktop.”

In contrast, the computers currently occupying space in our vehicles are relatively dim-witted by comparison, as Williamsen further explains, “the most powerful computer in a conventional vehicle is a very simple computer, because we need absolute complete reliability, they run at a fairly slow clock speed, they run at a fairly low amount of memory, and at a fairly simple number of words in their total programming and that’s because we need absolute boat-anchor levels of reliability”

“For autonomous vehicle research we are using computers … that are hundreds or thousands of times more powerful to do the processing, to put together the information of the complex LIDAR images and the information we are getting from multiple millimeter wave radar sensors.”

Driving, minus the driver

Velodyne LiDAR

So we have LIDAR, we have millimeter-wave radar, and we have an all-powerful Autobot brain running the show. But what’s actually driving digital Miss Daisy? For an autonomous vehicle to work, it needs to be controlled electronically, automatically, or to borrow a much more science-fictional term, robotically. These “robots” won’t overthrow the government, but instead kindly take over all the minutiae of driving. More than that, they all need to work in unison and, perhaps more importantly, independent of any human input.

In Toyota/Lexus’ case, its vehicles, namely its hybrid vehicles, already have what the company refers to as a “sophisticated hybrid system” capable of electronically controlling braking, steering, and acceleration. This particular domain of autonomous vehicle technology is essential, and is one of the reasons why Google utilizes Toyota/Lexus hybrids. In doing so, the Internet giant doesn’t need to develop its own electronically controlled interface, but instead simply figure out a way to reverse engineer the communications that allow it to create various steering, throttle, and braking commands.

While LIDAR is certainly the most visually prominent piece of driverless tech, every aspect of an autonomous vehicle is delicately intertwined with this spinning centerpiece. The automated steering controls depend on the millimeter-wave radar, while roof-mounted LIDAR frantically collects and maps vital information. That information needs to be processed, calculated, and ultimately fed back to the automated controls; thus completing this halcyon circle of automotive wizardry.

Movies & TV

Why First Man’s Oscar-nominated visual effects are a giant leap for filmmaking

Paul Lambert, the award-winning visual effects supervisor on First Man, reveals the innovative techniques that blended old footage with modern movie magic to make the Apollo 11 mission to the moon resonate with audiences 50 years later and…
Product Review

Mercedes-Benz updates the timeless G-wagen for the modern world

For decades, the G-Class has been an outlier in the Mercedes-Benz portfolio, a body-on-frame brute with the soul – and driving manners – of an off-road pickup. With the all-new G550, Mercedes seeks to smooth out some of the rough edges.
Emerging Tech

Awesome Tech You Can’t Buy Yet: Grow veggies indoors and shower more efficiently

Check out our roundup of the best new crowdfunding projects and product announcements that hit the web this week. You may not be able to buy this stuff yet, but it sure is fun to gawk!
Product Review

The 2020 Volvo V60 Cross Country is a do-it-all Swedish army knife

Volvo laced up its smallest station wagon in hiking clothes to create the V60 Cross Country. It's a lifted, all-wheel drive wagon that laughs at icy roads while coddling its occupants. We travel to Sweden to try it out.
Cars

2019 RAM 1500 Classic Warlock special edition: Badass style without the whoop

If you like the looks of blacked-out badass trucks without the cost of a desert racer, FCA announced the 2019 Ram 1500 Classic Warlock, a special edition pickup that focuses on appearance with only a touch of additional off-road capability.
Cars

2020 GMC Acadia toughens up on the outside, gets smarter on the inside

The 2020 GMC Acadia crossover gets styling updates and a more rugged AT4 trim level. Under the skin, the Acadia sports a new turbocharged four-cylinder engine and a wider array of tech features.
Cars

Nissan is using old Leaf batteries to power and connect off-the-grid campers

Nissan has teamed up with trailer manufacturer Opus to design a mobile, weatherproof power pack built with battery cells sourced from the first-generation Leaf. Called Roam, the pack stores enough electricity to power a camper for up to a…
Cars

Alfa Romeo’s latest Ferrari-powered F1 race car is ready to hit the track

Alfa Romeo is doubling down on Formula One racing after a decades-long hiatus. Now essentially a support team for Ferrari, its 2019 driver lineup includes a former world champion and a potential future star.
Cars

Researchers teach self-driving cars to predict pedestrians’ next moves

University of Michigan researchers are developing a system that teaches self-driving cars to predict pedestrian movement. Humans don't always act in their own best self-interest, so autonomous cars will need to practice protective driving.
Cars

Subaru’s latest VIZIV concept car is pumped full of adrenaline

The Subaru VIZIV Adrenaline is the seventh member of the Japanese automaker's family of VIZIV concept cars. It debuts at the 2019 Geneva Motor Show, but for now, all we're getting is a shadowy teaser image.
Cars

Audi is advancing the tech that teaches cars to talk to traffic lights

Audi is teaching its cars the language of traffic lights. The company developed technology that tells motorists what speed they should drive at in order to catch as many green lights as possible.
Cars

Waymo rules and Apple trails in California self-driving car benchmarks

California's DMV releases annual reports of self-driving car disengagements on public roads. In the most recent reports. Waymo had the best performance, GM Cruise came in second, and Apple's self-driving program was in last place.
Cars

Watch a modified Audi e-tron electric SUV drive straight up a ski slope

A modified Audi e-tron climbed up an 85-percent gradient on an Austrian ski slope in a tribute to a classic Audi commercial. The vehicle used for the stunt sported an extra electric motor and spiked tires.
Cars

Mamma mia! Alfa Romeo will unveil a new model at the Geneva Auto Show

Alfa Romeo told Digital Trends it will unveil a new model at the 2019 Geneva Auto Show. It stopped short of revealing what it has in store, but rumors claim it will be a crossover positioned below the Stelvio.