Tesla's Autopilot system uses cameras and radar, but not laser-based lidar as some other self-driving systems do. The company said its system would have had trouble distinguishing a white semi-trailer positioned across a road against a bright sky.
Autopilot, the semiautonomous driving technology in Tesla Motors vehicles, will rely on radar rather than information primarily gathered by camera sensors to initiate braking, CEO Elon Musk said on Sunday.
The company is making the change after Joshua Brown was killed in May in Florida when the Autopilot in his Tesla Model S did not to recognize a truck in his path and initiate braking. Autopilot will now use radar and camera sensors together to determine braking events, rather than sensors supplemented by radar information.
The transition to radar will be made available to Tesla vehicles worldwide via software upgrade, and is expected to roll out within two weeks. The technology was developed by Tesla after the company ended its partnership with software company Mobileye in July.
"This is adding another layer of safety, but this does not mean perfect safety," Musk said.
The new radar detection is expected to recognize obstacles more than one car away and use fleet learning to avoid braking for minor objects like a soda can or small animal. Emergency braking will also be initiated by the vehicle when Autopilot is inactive.
The update will also make it more difficult for drivers to keep their hands off the wheel while Autopilot is engaged. If a driver has been warned three times within one hour to put his hands on the wheel, he must park the car before Autopilot can be activated again.
The automaker has received scrutiny from the National Highway Traffic Safety Administration for accidents that have occurred while Autopilot was engaged. However, the agency has expressed support for the safety benefits of automated driving technology.
"We should be desperate for anything we can find to save people's lives," NHTSA Administrator Mark Rosekind said at a July conference.
Musk declined to call the change a recall, saying it was merely a software upgrade. "[NHTSA] appear[s] to be pretty happy with the changes," he said.