TESLA Motors has announced sweeping changes overnight to the way its cars see objects in front of them – and slam on the brakes in an emergency.
Rather than using a camera to detect an object in front of the car before slamming on the brakes in an emergency, the carmaker will now rely solely on the radar system once used as a back-up.
It’s the first major revision to Tesla’s automatic emergency braking system since a Tesla Model S driver was killed after his car slammed into the side of a white semi-trailer crossing the road in front of him after the system’s camera allegedly failed to pick it up in bright sunlight.
The change in focus is part of the rollout of the eighth version of its experimental autonomous driving software – the carmaker goes to great pains these days to warn drivers that they can’t rely fully on the technology to take over control, and must keep a watchful eye on things at all times.
“...The most significant upgrade to Autopilot will be the use of more advanced signal processing to create a picture of the world using the onboard radar,” Tesla said in a statement announcing the change.
“The radar was added to all Tesla vehicles in October 2014 as part of the Autopilot hardware suite, but was only meant to be a supplementary sensor to the primary camera and image processing system.
“After careful consideration, we now believe it can be used as a primary control sensor without requiring the camera to confirm visual image recognition.”
Tesla then goes on to explain how difficult it is for the car to “see” the world around it using radar.
“Photons of that wavelength travel easily through fog, dust, rain and snow, but anything metallic looks like a mirror,” it said.
“The radar can see people, but they appear partially translucent. Something made of wood or painted plastic, though opaque to a person, is almost as transparent as glass to radar.
“On the other hand, any metal surface with a dish shape is not only reflective, but also amplifies the reflected signal to many times its actual size.
“A discarded soda can on the road, with its concave bottom facing towards you can appear to be a large and dangerous obstacle, but you would definitely not want to slam on the brakes to avoid it.
“Therefore, the big problem in using radar to stop the car is avoiding false alarms.”
According to Tesla, slamming on the brakes at every false reading “would at best be very annoying and at worst cause injury”.
To help, the Tesla radar system now recognises more points, which it then uses to build a map of the world around it.
Tesla said it would also use its cars to build a database of false alarms, so that if its cars constantly jump on the brakes at a dip in the road, the software learns that it doesn’t need to be so overly sensitive the next time it passes through that section of road.
It said the technology was also now at the stage where it could bounce the radar off the road and under vehicles in front, allowing it to “see” up to two cars ahead and react accordingly if it needed to jump on the brakes in an emergency.
Tesla owners can have their car’s software updated automatically via the mobile phone network. The carmaker says upgrades are timed so that they happen while the car is parked.
Owners also need to agree to have the software installed on the car, via a menu that pops up on the car’s large central screen.
The changes to the automatic emergency braking system are among around 200 changes rolled out in the new software package.
While Tesla is a member of the Federal Chamber of Automotive Industries, which represents the interests of car manufacturers in Australia and reports their monthly new-car sales, Tesla does not report its sales in Australia.