5 ms·

The pre-collision avoidance should have kicked in either way. My Subaru has saved me once or twice when a car in front of me braked harder than I realized, and

The pre-collision avoidance should have kicked in either way. My Subaru has saved me once or twice when a car in front of me braked harder than I realized, and they’re not even claiming anything close to full self driving.

londons_explore 5y ago
The Subaru wouldn't stop for a stationary vehicle though. Most of those systems either don't work at all for stationary vehicles, or work far less reliably. They're mostly designed for the case you described - car ahead slows suddenly and the driver isn't paying attention.
- ashtonkem 5y ago
  > Most of those systems either don't work at all for stationary vehicle Citation needed. Subaru claims their eye sight system will detect and attempt to brake for a stationary vehicle. Whether or not they’ll managed to halt the vehicle is obviously speed dependent, but obviously slowing down before the crash is vastly superior to maintaining speed.
- anu7df 5y ago
  Care to clarify what you mean here? Had a subaru outback with eyesight a few years ago and I tested it with stationary objects in path multiple times (cardboard boxes and such). The subaru braked and stopped short of the objects 100% of the time.
  - londons_explore 5y ago
    When the vehicle you're about to collide with is moving slowly, there are good radar returns, so you can use both vision and radar to make the decison. When the vehicle is stationary, the radar data has to be heavily filtered because radar has poor angular resolution and there are a lot of other stationary objects, many that you don't want to stop for at similar angles, like overhead road signs. That means you're relying purely on vision, which alone has a lot of false positives and negatives, so detection thresholds need to be set much lower. Doesn't mean it won't work. Just means it's less likely to work, especially in the dark and the rain, where radar would normally be a big part of the signal.
    - faeyanpiraat 5y ago
      When I was driving a 2014 Volvo, it also automatically stopped before hitting a stationary cardboard box (up to 30 kph)
    - ashtonkem 5y ago
      Not all these systems are radar. Subaru uses cameras, in fact.
kwhitefoot 5y ago
My 2015 Model S does that too. And also often detects stationary vehicles that it thinks might be in the way.

londons_explore 5y ago

The Subaru wouldn't stop for a stationary vehicle though. Most of those systems either don't work at all for stationary vehicles, or work far less reliably. They're mostly designed for the case you described - car ahead slows suddenly and the driver isn't paying attention.

ashtonkem 5y ago
> Most of those systems either don't work at all for stationary vehicle Citation needed. Subaru claims their eye sight system will detect and attempt to brake for a stationary vehicle. Whether or not they’ll managed to halt the vehicle is obviously speed dependent, but obviously slowing down before the crash is vastly superior to maintaining speed.
anu7df 5y ago
Care to clarify what you mean here? Had a subaru outback with eyesight a few years ago and I tested it with stationary objects in path multiple times (cardboard boxes and such). The subaru braked and stopped short of the objects 100% of the time.
- londons_explore 5y ago
  When the vehicle you're about to collide with is moving slowly, there are good radar returns, so you can use both vision and radar to make the decison. When the vehicle is stationary, the radar data has to be heavily filtered because radar has poor angular resolution and there are a lot of other stationary objects, many that you don't want to stop for at similar angles, like overhead road signs. That means you're relying purely on vision, which alone has a lot of false positives and negatives, so detection thresholds need to be set much lower. Doesn't mean it won't work. Just means it's less likely to work, especially in the dark and the rain, where radar would normally be a big part of the signal.
  - faeyanpiraat 5y ago
    When I was driving a 2014 Volvo, it also automatically stopped before hitting a stationary cardboard box (up to 30 kph)
  - ashtonkem 5y ago
    Not all these systems are radar. Subaru uses cameras, in fact.

kwhitefoot 5y ago

My 2015 Model S does that too. And also often detects stationary vehicles that it thinks might be in the way.