The Tempe, Arizona crash involving a self-driving Volvo XC90 SUV from Uber that resulted in a death of a 49-year-old woman earlier this month is raising questions about the overall design of the company’s latest autonomous vehicle fleet, specifically in regards to the number of safety sensors it has. Whereas the firm’s original Ford Fusion models were equipped with seven LiDARs and ten radars, the SUVs that replaced them in 2016 feature only a single LiDAR module on the roof and seven radars, with the only upgrade being observable in the number of conventional cameras they have, which has been raised from seven to twenty.
The lack of additional LiDARs increases the volume of the car’s blind spots compared to the initial Ford Fusion models and rivaling autonomous vehicles, Reuters reported earlier this week, citing several industry experts and a handful of former employees of Uber’s Advanced Technologies Group. LiDAR sensors — which were also at the center of Uber’s recently concluded legal clash with Alphabet’s Waymo — rely on laser pulses to map their surroundings and identify traffic participants, as well as other objects. By lowering the number of such modules, Uber made its vehicles more susceptible to failing to detect potential dangers on the road, including jaywalking pedestrians, one of whom was killed by its experimental vehicle on March 18.
A single LiDAR sensor is not enough to provide maximum safety guarantees due to its narrow vertical angle that makes it unable to detect objects close to the ground and car itself, which is why using multiple such modules is recommended. Uber’s car is equipped with a LiDAR solution manufactured by Velodyne which also supplies numerous other companies. In a statement provided to Reuters, Velodyne President Marta Hall said side LiDARs are a necessity for having a vehicle fully capable of avoiding pedestrians, particularly at night. The Tempe crash happened before dawn in poor lighting, with the video footage of the incident released by local authorities suggesting the jaywalking victim was difficult to spot. Uber halted all of its self-driving trials following the crash but also got its testing permit suspended by Arizona Governor earlier this week. The future of the company’s autonomous driving program remains unclear, with the firm also not reapplying for renewing its California permit which expires at the end of this month.