Volvo Engineers Luminar Lidar into 2024 EX90
A Luminar Iris lidar in the 2024 EX90 is engineered to enhance both automated driving and safety.
Consumer skepticism over autonomous vehicles is running rampant, thanks largely to Tesla’s broken-record promises to make “Full Self Driving” a reality — along with high-profile accidents, fatalities, and a U.S. federal investigation of its Autopilot system. Tesla and other automakers also continue a public spat over the best technical or social solutions. And with everyone from General Motors to Mercedes-Benz struggling to leap beyond SAE-defined Level 2 driver-assistance, Volvo has apparently had enough.
With safety as its brand-defining hallmark, the Swedish OEM threw down a gantlet at the Stockholm unveiling of its electric EX90 SUV: In Volvo’s contrarian view, there is no need to pursue hands-free Level 2 systems such as GM’s Super Cruise, which still expect drivers to watch the road and retake control at a moment’s notice. To Volvo, driving will be either supervised or unsupervised. The space in-between is a potentially unsafe limbo, at least for now.
To that end, Volvo executives said their flagship EX90 will go on sale in 2024 with all the hardware required for fully unsupervised (SAE Level 4) driving. The system’s linchpin is the first rooftop-mounted lidar unit on an international-market passenger vehicle, developed by the Florida-based Luminar. Known as Iris, the full-stack system is considered semi-solid-state, its scanning mode using larger ‘macro’ scanning mirrors rather than MEMS’ micro mirrors. Iris’s light source is a 1550-nm fiber laser, the longer wavelength (vs. more typical 905-nm shorter-wavelength lasers) being harmless to the human eye. The lidar’s receiver uses indium gallium arsenide (InGaAs) microchip technology rather than silicon. Claimed resolution is greater than 300 points per square degree.
The Iris uses pulsed, time of flight (ToF) target illumination that Luminar engineers claim delivers an exceptionally fast measurement rate, an immediate understanding of reflectance, and no speed-dependent range error. Iris scans a vehicle’s surroundings in real time, firing millions of laser pulses to create a virtual 3D map, with no need for GPS or a cellular connection. The lidar itself has a 120° field of view (FoV) and a 26° dynamic vertical FoV. It’s part of 30-sensor array — including 16 ultrasonic sensors, five radars and eight cameras — to deliver 360-degree views around the electric SUV.
A camera in the EX90’s interior handles driver monitoring. It uses artificial intelligence (AI) that can detect not only driver inattention, but also driver intoxication or medical impairment. The camera works in conjunction with a cabin-focused onboard radar capable of detecting the breathing of occupants, from a strapped-in infant to a slumbering pet, to ensure nobody is accidentally left behind.
Lidar’s detection benefits
Elon Musk has been lidar’s most-famous skeptic, branding it as a “crutch” and a “fool’s errand.” But Musk now stands nearly alone among automakers and automated-driving tech experts who see a profusion of redundant onboard sensors as a good thing.
The cameras Tesla relies on almost exclusively can struggle in darkness, poor weather or blinding light, especially when trying to make sense of broad surfaces, noted Matthew Weed, Ph.D, an optical scientist, engineer and product director at Luminar. Imagine staring at a featureless wall, where only the edges stand out, he offered.
In contrast, the Luminar Iris can detect and classify objects to a maximum range of 600 meters (1969 ft.), even at night. It can spot a pedestrian or animal darting across the road at up to 250 m (820 ft.). It can “see” an errant tire in the road, or other small objects, at up to 120 m (394 ft.). And where the acuity of laser-based vision systems typically degrades through snow or rain, the Iris technology does so very gradually, Weed told SAE Media.
“You might lose some light energy when lidar hits snowflakes, but you still get enough back to get a useful, fundamentally 3D image,” he explained. If radar sensors struggle to definitively acquire an object ahead, or bird poop fouls a camera lens, lidar remains a trusty backstop.
“Even if you then lose the lidar, you’ve still stored the last few frames of environmental info,” Weed noted. “You still know the few hundred meters in front of you and can make reasonable assumptions of where and where not to operate.”
To a software integrator, lidar “lets you take steps of responsibility that other automakers haven’t yet road-mapped,” he asserted.
Ödgärd Andersson, CEO of the Volvo-owned autonomous software company Zenseact, said the redundancy engineered into the EX90’s perception system will help future Volvos solve tricky “edge cases” and make real-time decisions without such glitches as phantom braking.
“You have to have enough confident data to be able to act on it,” she said. “We can now see in scenarios that are very difficult for humans, including nighttime when there are statistically far more accidents.”
Based on its voluminous, half-century-old database of real-world accidents, Volvo confidently asserts that the lidar-based sensor suite – in tandem with new core computing and software –will reduce serious-injury accidents by up to 20% and eliminate one in 10 accidents overall.
Until recently, the public face of lidar was the large, “spinning chicken bucket” electromechanical rooftop systems on robotaxis from startups such as Google’s Waymo. While these older systems, with their stacked arrays, still are widely employed in vehicles used for mapping and testing, advances from Luminar and others in creating simpler, lower-cost systems (the Iris’s 2-axis scanner spins only the laser rather than spinning the whole lidar device) are defying predictions that lidar would remain too expensive, bulky or complicated for production vehicles.
That doesn’t mean the EX90 integration was a breeze, says T. Jon Mayer, who heads up Volvo’s California design center. When Volvo first saw the Luminar Iris lidar, “We thought, ‘Where are we going to hide this thing’?” Mayer says of a unit measuring nearly 18 inches (457 mm) tall and wide.
Mayer’s design team and Volvo engineers considered squeezing the lidar into the EX90’s grille, but quickly dismissed that idea. “All you’d see is the car in front of you, but we wanted to see 250 meters, day or night,” Mayer asserted, applying the analogy of animals whose eyes are universally up high: “You don’t see an animal walking with its eyes at its knees, whether it’s a lizard or a giraffe.”
So, the lidar is elegantly integrated into the EX90’s front roofline, where it resembles a small hood scoop shielded by a transparent cover. The teardrop-shaped unit is sculpted to allow airflow to pass over and reattach to the roof, creating as little turbulence as possible in this wind-cheating electric SUV. Water nozzles at the end of the EX90’s windshield wipers cleverly clean the lidar protective screen as they sweep near the roof. Two other nozzles clean side-facing fish-eye cameras embedded in exterior mirrors to greatly expand views through intersections.
“We see the lidar as a symbol of 21st century automotive safety, like our three-point seatbelt was in the 20th century,” Mayer says. That relative bird’s-eye view brings a more-subtle advantage, Weed noted: A higher angle-of-incidence makes it much easier to measure and make sense of the roadway.
“The lower to the ground you are, the less far you can detect the road and lane markers. Mounted on a tall truck, we can see for days,” he said.
Sweden’s Volvo, owned by Geely Holdings of China, will integrate the roof-mounted sensor on other models built on its SPA2 platform, including the South Carolina-built Polestar 3 from Volvo’s new EV division. Luminar’s tech already is going into a Chinese model from SAIC and should see light of day on both upcoming Mercedes-Benz models and Nissans built on a new EV platform.
Weed confirmed Luminar has steadily cut automakers’ cost for the Iris system to about $500-to-$1,000 range. A significant cost reduction came from a mixed-signal ASIC (application-specific integrated circuit) developed in-house that delivers higher performance than complex ADC (analog-to-digital converter) chips, he noted.
‘Diamonds of data’
Powerful Nvidia-based core computing is another key to the EX90’s performance. Andersson said it will use machine learning and collect data to help Volvo understand and refine operating behavior. The “diamonds of data” that Volvos collect will go into driving simulations to improve performance in tricky real-world scenarios, with Tesla-like improvements delivered via over-the-air (OTA) updates.
While GM, BMW, Mercedes-Benz and others have been rolling out hands-free systems featuring increasing sophistication, Volvo argues those systems have no proven safety benefit. Those Level 2 and 3 driver-assistance systems may even detract from safety, by lulling drivers into inattention or a false sense of security. Where GM touts its Super Cruise as strictly a convenience feature for now — avoiding any real claims for accident of injury reduction — Volvo insists it will never roll out semi-autonomous or autonomous functions until it has hard data showing accident reductions or other safety benefits.
“We fundamentally believe autonomous driving can and will be a safety gain,” asserted Lotta Jakobsson, senior technician for injury prevention.
The EX90’s hardware and software still will support Advanced Driver Assistance Systems (ADAS) that dovetail with commonly understood Level 2 functions such as automated emergency braking, pedestrian/cyclist detection and adaptive cruise controls. The new sensors will improve the reliability and performance of Volvo’s assisted-driving Pilot Assist system, including new steering support during lane changes.
Henrik Green, Volvo’s head of advanced technology and sustainability, underlined that his company will take its usual conservative approach to rolling out unsupervised driving via OTA software updates, likely beginning with limited use on geofenced highways. Green acknowledged Volvo has been slower than some rivals in bringing semi-autonomous functions to market. But the company must stay true to its values, he asserted.
“Safety comes before being fast,” Green said.