29 March, 2018, 12:00 am
TEMPE, Ariz./PITTSBURGH – When Uber decided in 2016 to retire its fleet of self-driving Ford Fusion cars in favour of Volvo sport utility vehicles, it also chose to scale back on one notable piece of technology: the safety sensors used to detect objects in the road.
That decision resulted in a self-driving vehicle with more blind spots than its own earlier generation of autonomous cars, as well as those of its rivals, according to interviews with five former employees and four industry experts who spoke for the first time about Uber’s technology switch.
Driverless cars are supposed to avoid accidents with lidar — which uses laser light pulses to detect hazards on the road — and other sensors such as radar and cameras.
The new Uber driverless vehicle is armed with only one roof-mounted lidar sensor compared with seven lidar units on the older Ford Fusion models Uber employed, according to diagrams prepared by Uber.
In scaling back to a single lidar on the Volvo, Uber introduced a blind zone around the perimeter of the SUV that cannot fully detect pedestrians, according to interviews with former employees and Raj Rajkumar, the head of Carnegie Mellon University’s transportation center who has been working on self-driving technology for over a decade.
The lidar system made by Velodyne – one of the top suppliers of sensors for self-driving vehicles — sees objects in a 360-degree circle around the car, but has a narrow vertical range that prevents it from detecting obstacles low to the ground, according to information on Velodyne’s website as well as former employees who operated the Uber SUVs.
Autonomous vehicles operated by rivals Waymo, Alphabet Inc’s self-driving vehicle unit, have six lidar sensors, while General Motors Co’s vehicle contains five, according to information from the companies.
Uber declined to comment on its decision to reduce its lidar count. In a statement late Tuesday, an Uber spokeswoman said: “We believe that technology has the power to make transportation safer than ever before and recognise our responsibility to contribute to safety in our communities.
“As we develop self-driving technology, safety is our primary concern every step of the way.”
Uber referred questions on the blind spot to Velodyne. Velodyne acknowledged that with the rooftop lidar there is a roughly three meter blind spot around a vehicle, saying that more sensors are necessary.