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This thread is unhelpfully mixing radar and ultrasonic sensors. Ultrasonic sensors, as your video explains, are primarily used as a parking aid; they are tuned

This thread is unhelpfully mixing radar and ultrasonic sensors. Ultrasonic sensors, as your video explains, are primarily used as a parking aid; they are tuned for too low a distance to be helpful in just about any kind of driving scenario at speed. Meanwhile, radar is the principal sensor used in systems like automatic emergency braking across the industry. It has no intersection with any of the parking stuff because it generally has to ignore stationary objects to be useful (hence the whole "Teslas crashing full speed into stopped vehicles" thing).

RC_ITR 4y ago
The first famous autopilot crash was because a white semi-truck was washed out by the sun and confused for an overhead sign. That's literally trivial for a car with radar to detect. Amazing how people talk about stuff they have no idea about when it comes to Tesla.
- eightysixfour 4y ago
  Not a fan of Tesla removing the sensors but a vehicle on a highway that isn’t moving the same direction as the car is not “trivial” with radar. No AEBs that use radar look for completely stopped objects after a certain speed because the number of false positives is so high.
  - RC_ITR 4y ago
    So, yes, cars that are programmed to have AEB: perform well at AEB and not other tasks. We are in agreement here. (I even agree with you that those cars use Radar for AEB). Now, where we disagree is you implying that cars with AEB-level radar (literally $10 off-the-shelf parts with whatever sensor fusion some MobilEye intern dreams ups) are somehow the same as self-driving cars (the goal of Tesla Autopilot). Every serious self-driving car/tractor-trailer out there uses radar as a component of its sensor stack because Lidar and simple imaging is not sufficient. And that's the point I was trying to make - we agree it's trivial for radar to find things they just need sensor fusion to confirm the finding and begin motion planning. This is why a real driverless car is hard despite what Elon would like you to believe. There is no one sensor that will do it. Full stop. And this cuts to the core of why Tesla is so dangerous. They are making a car with AEB and lane-keeping and moving the goal posts to make people (you included) think that's somehow a sane approach to driverless cars.
    - kalleboo 4y ago
      But if the radar just sees a static object and can't tell if it's an overhead sign or a car, and the camera vision is too washed out, how would sensor fusion help in your example?
      - sangnoir 4y ago
        Perhaps stop cheaping out on the cameras and procure those with high dynamic range. Then again those may be "expensive and complicate the supply chain with for a small delta"
        kalleboo 4y ago
        But then, again, what is the point of the radar?
      - cbsmith 4y ago
        Lidar would make it pretty obvious whether it's a sign or a car, even if the camera didn't tell you. The part where the lidar doesn't bounce back at vehicle level would be a dead give away.
        robertlagrant 4y ago
        A approaching incline has entered the chat.
        cbsmith 4y ago
        Approaching inclines aren't exactly hard to interpret from lidar either.
      - pcl 4y ago
        A human driver slows down and moved their head around to get a better view when the glare from the sun is too strong to see well. I’d expect a self driving car to similarly compromise on speed for the sake of safety, when presented with uncertainty.
  - LightG 4y ago
    Which is another reason that "full" FSD is at least a decade away and likely from another supplier, if at all. Cannot believe people are funding this.
- deleted 4y ago
  [deleted]
- Reason077 4y ago
  > ”The first famous autopilot crash was because a white semi-truck was washed out by the sun and confused for an overhead sign. That's literally trivial for a car with radar to detect.” That crash occurred on a car which was using radar. Automotive radar generally doesn’t help to detect stationary objects. Further, that crash occurred on a vehicle with the original autopilot version (AP1), which was based on Mobileye technology with Tesla’s autopilot software layered on top. Detection capabilities would have been similar to any vehicle using Mobileye for AEB at the time.
  - touisteur 4y ago
    I find very strange the claim that a moving doppler (pulsed doppler?) radar 'generally doesn't help to detect stationary objects'. I mean if the car is moving, it generates a doppler shift on all objects moving at a different speed, right? Maybe it's difficult for reasons of false alarm detection (too many stationary objects that are not of interest) but you can get very good results with tracking (curious about these radars' refresh rate), STAP, and classification/identification algorithms, especially if you have a somewhat modern beamformed signal (so, some kind instant spatial information). Active-tracking can also be of help here if you can beamsteer (put more energy, more waveform diversity on the target, increase the refresh rate). Can't these radars do any of those 'state of the art 20 years ago' stuff? There's something I don't get here and I feel I need some education...
    - Someone 4y ago
      > I find very strange the claim that a moving doppler (pulsed doppler?) radar 'generally doesn't help to detect stationary objects'. I mean if the car is moving, it generates a doppler shift on all objects moving at a different speed, right? I’m in the same boat as to not understanding why, but from what I have read the problem indeed isn’t that it doesn’t detect them, it’s that there are too many of them, and nobody has figured out how to filter out the 99+% of signals you have to ignore from the ones that may pose a risk, if it’s doable at all. I think that at last part of the reason is that spatial resolution of radar isn’t great, making it hard to discriminate between stationary objects in your path and those close to it (parked cars, traffic signs, etc). Also, some small objects in your path that should be ignored such as soda cans with just the ‘right’ orientation can have large radar reflections.
- stillworks 4y ago
  That's literally trivial for a car with radar to detect. In principle that is correct… but radars in automotive application are unable (or rather not used) to detect non-moving targets ? Asking this because I know first hand that the adaptive cruise function in my car must have a moving vehicle in front of it for the adaptive aspect to work. It will not detect a vehicle that is already stopped. The resolution of the radar is pretty good though, even if the vehicle in the front is just merely creeping off breaks… it does get detected if it is at or more than the “cruising distance” set up initially. The AEB function on my car depends on the camera.
  - cbsmith 4y ago
    Adaptive cruise control is solving a totally different problem. It is specifically looking for moving objects to match pace with. That's very different from autonomous driving systems. Radar is quite good at finding stationary metal objects, particularly. Putting it in a car, if anything, helps, because the station objects are more likely to be moving relative to the car...
  - ra7 4y ago
    The newer “4D imaging” radars can track stationary objects too. This is what the self driving companies have turned to in recent times.
  - tim-fan 4y ago
    My understanding is that your typical automotive radar will have insufficient angular resolution to reliably distinguish, say, an overpass from a semi blocking the road, or a pedestrian standing in the middle of the road from one on the footpath. Radar does however have the advantage of measuring object speed directly via the doppler effect, so you can filter out all stationary objects reliably, then assume that all moving objects are on the road in front of you and need to be reacted/responded to. So I think it's the case that radar can detect stationary objects easily, but cannot determine their position enough to be useful, hence in practice stationary objects are ignored.
- leetharris 4y ago
  What a smug post from someone who is completely wrong. The car that crashed had radar, vision, USS, AND it was based on another company's technology.
abracadaniel 4y ago
The kicker for me is that the area covered by the ultrasonic sensors is essentially all blind spots for the cameras. The sensors currently are able to tell you when something too low to see is getting within a few inches of the car. It also gives an exact distance when parking, so I can know that I'm parking exactly 2ft from the wall every time. As much as they claim otherwise, it simply cannot be a matter of fixing it in software. The cameras can't tell you what they can't see. They simply don't have the coverage to do this, and clearly don't even have the coverage to hit parity with radar enabled autopilot either.

RC_ITR 4y ago

The first famous autopilot crash was because a white semi-truck was washed out by the sun and confused for an overhead sign. That's literally trivial for a car with radar to detect. Amazing how people talk about stuff they have no idea about when it comes to Tesla.

eightysixfour 4y ago
Not a fan of Tesla removing the sensors but a vehicle on a highway that isn’t moving the same direction as the car is not “trivial” with radar. No AEBs that use radar look for completely stopped objects after a certain speed because the number of false positives is so high.
- RC_ITR 4y ago
  So, yes, cars that are programmed to have AEB: perform well at AEB and not other tasks. We are in agreement here. (I even agree with you that those cars use Radar for AEB). Now, where we disagree is you implying that cars with AEB-level radar (literally $10 off-the-shelf parts with whatever sensor fusion some MobilEye intern dreams ups) are somehow the same as self-driving cars (the goal of Tesla Autopilot). Every serious self-driving car/tractor-trailer out there uses radar as a component of its sensor stack because Lidar and simple imaging is not sufficient. And that's the point I was trying to make - we agree it's trivial for radar to find things they just need sensor fusion to confirm the finding and begin motion planning. This is why a real driverless car is hard despite what Elon would like you to believe. There is no one sensor that will do it. Full stop. And this cuts to the core of why Tesla is so dangerous. They are making a car with AEB and lane-keeping and moving the goal posts to make people (you included) think that's somehow a sane approach to driverless cars.
  - kalleboo 4y ago
    But if the radar just sees a static object and can't tell if it's an overhead sign or a car, and the camera vision is too washed out, how would sensor fusion help in your example?
    - sangnoir 4y ago
      Perhaps stop cheaping out on the cameras and procure those with high dynamic range. Then again those may be "expensive and complicate the supply chain with for a small delta"
      - kalleboo 4y ago
        But then, again, what is the point of the radar?
    - cbsmith 4y ago
      Lidar would make it pretty obvious whether it's a sign or a car, even if the camera didn't tell you. The part where the lidar doesn't bounce back at vehicle level would be a dead give away.
      - robertlagrant 4y ago
        A approaching incline has entered the chat.
        cbsmith 4y ago
        Approaching inclines aren't exactly hard to interpret from lidar either.
    - pcl 4y ago
      A human driver slows down and moved their head around to get a better view when the glare from the sun is too strong to see well. I’d expect a self driving car to similarly compromise on speed for the sake of safety, when presented with uncertainty.
- LightG 4y ago
  Which is another reason that "full" FSD is at least a decade away and likely from another supplier, if at all. Cannot believe people are funding this.
deleted 4y ago
[deleted]
Reason077 4y ago
> ”The first famous autopilot crash was because a white semi-truck was washed out by the sun and confused for an overhead sign. That's literally trivial for a car with radar to detect.” That crash occurred on a car which was using radar. Automotive radar generally doesn’t help to detect stationary objects. Further, that crash occurred on a vehicle with the original autopilot version (AP1), which was based on Mobileye technology with Tesla’s autopilot software layered on top. Detection capabilities would have been similar to any vehicle using Mobileye for AEB at the time.
- touisteur 4y ago
  I find very strange the claim that a moving doppler (pulsed doppler?) radar 'generally doesn't help to detect stationary objects'. I mean if the car is moving, it generates a doppler shift on all objects moving at a different speed, right? Maybe it's difficult for reasons of false alarm detection (too many stationary objects that are not of interest) but you can get very good results with tracking (curious about these radars' refresh rate), STAP, and classification/identification algorithms, especially if you have a somewhat modern beamformed signal (so, some kind instant spatial information). Active-tracking can also be of help here if you can beamsteer (put more energy, more waveform diversity on the target, increase the refresh rate). Can't these radars do any of those 'state of the art 20 years ago' stuff? There's something I don't get here and I feel I need some education...
  - Someone 4y ago
    > I find very strange the claim that a moving doppler (pulsed doppler?) radar 'generally doesn't help to detect stationary objects'. I mean if the car is moving, it generates a doppler shift on all objects moving at a different speed, right? I’m in the same boat as to not understanding why, but from what I have read the problem indeed isn’t that it doesn’t detect them, it’s that there are too many of them, and nobody has figured out how to filter out the 99+% of signals you have to ignore from the ones that may pose a risk, if it’s doable at all. I think that at last part of the reason is that spatial resolution of radar isn’t great, making it hard to discriminate between stationary objects in your path and those close to it (parked cars, traffic signs, etc). Also, some small objects in your path that should be ignored such as soda cans with just the ‘right’ orientation can have large radar reflections.
stillworks 4y ago
That's literally trivial for a car with radar to detect. In principle that is correct… but radars in automotive application are unable (or rather not used) to detect non-moving targets ? Asking this because I know first hand that the adaptive cruise function in my car must have a moving vehicle in front of it for the adaptive aspect to work. It will not detect a vehicle that is already stopped. The resolution of the radar is pretty good though, even if the vehicle in the front is just merely creeping off breaks… it does get detected if it is at or more than the “cruising distance” set up initially. The AEB function on my car depends on the camera.
- cbsmith 4y ago
  Adaptive cruise control is solving a totally different problem. It is specifically looking for moving objects to match pace with. That's very different from autonomous driving systems. Radar is quite good at finding stationary metal objects, particularly. Putting it in a car, if anything, helps, because the station objects are more likely to be moving relative to the car...
- ra7 4y ago
  The newer “4D imaging” radars can track stationary objects too. This is what the self driving companies have turned to in recent times.
- tim-fan 4y ago
  My understanding is that your typical automotive radar will have insufficient angular resolution to reliably distinguish, say, an overpass from a semi blocking the road, or a pedestrian standing in the middle of the road from one on the footpath. Radar does however have the advantage of measuring object speed directly via the doppler effect, so you can filter out all stationary objects reliably, then assume that all moving objects are on the road in front of you and need to be reacted/responded to. So I think it's the case that radar can detect stationary objects easily, but cannot determine their position enough to be useful, hence in practice stationary objects are ignored.
leetharris 4y ago
What a smug post from someone who is completely wrong. The car that crashed had radar, vision, USS, AND it was based on another company's technology.

abracadaniel 4y ago

The kicker for me is that the area covered by the ultrasonic sensors is essentially all blind spots for the cameras. The sensors currently are able to tell you when something too low to see is getting within a few inches of the car. It also gives an exact distance when parking, so I can know that I'm parking exactly 2ft from the wall every time. As much as they claim otherwise, it simply cannot be a matter of fixing it in software. The cameras can't tell you what they can't see. They simply don't have the coverage to do this, and clearly don't even have the coverage to hit parity with radar enabled autopilot either.