Phantom braking

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MelindaV

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Has Elon said HOW phantom braking and crashing into stopped cars (2 sides of the same coin) will be fixed (beyond just improving the neural net)? I know he hates Lidar but wouldn’t this address the problem? It’s going to have to be fixed if FSD is ever considered safe.
it will not be lidar. Lidar is not priced competitively enough to be used on a production rollout car. at least not to date, or in the foreseeable future.
 

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This -20 offset workaround would be great if it just disables Auto PSL Adjustment (possible bulk of Phantom Braking) and engages at current throttle speed.

Thanks !! Worth a shot for sure.
I've been running this -20 offset for like a month now. I have to say it has improved things a lot.

However, I do miss it starting off at the posted speed limit when I engage TACC, not a huge deal, but I do miss it.

It is not full proof. One thing I have learned is that when the car does say slow down aggressively, say by a mere 20 mph, it feels like it slammed on the brakes hard, maybe it did, but I think it feels worse than it really is.

I was driving home on a 120 mile trip the other day and I did have a couple phantom brakes. But each one seemed, albeit overly cautious and not something I would ever do, but there were reasons for them. I'm ok with that.

In one case, I was zooming into a toll booth quicker than I normally do (I usually slow way sooner than 95% of the other drivers). I typically cancel TACC early to get good regen. But there was a car jockeying for a slot so I kept my speed up a little longer (more in line with other cars). More so to communicate to the other driver my intent for my lane choice, nothing aggressive. Out of the blue the car aggressively slowed down. Crap, I'm in a 35 mph zone doing 60. So if it's a large offset it will still change speed. Now it might have seen the toll booth as an obstacle. It was still a fair distance away. But it had good reason to slow down. Nothing on the screen, no warnings.

Another case was a Semi pulled over on the shoulder. I immediately looked down at the screen after it "Phantom Braked" and the Semi was not showing. There was no reason to brake, but I can see why it might have been cautious. Again no warning, no beep. Semi did look "out of place".

One other case was cars jockeying in lanes ahead but not in my lane.

Before the -20 Offset I used have so many cases of phantom braking with no clear reason at all, expect an overpass ahead (and sometimes not). Since doing the -20 offset that has not happened once.
I'm tempted to turn that back to normal (0 offset) to see how it's doing.
 
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Madmolecule

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I had a couple instances of phantom braking yesterday. 2019.24. I was the first time in a few months since this has occurred. Both times were shadows under a bridge, but on a flat surface this time. It definitely frustrated the driver behind me. It wasn’t as severe as it was in the past but very noticeable. I want to get a an “autopilot on board” sign but I can’t find one for sale, It used to be on eBay. We need someway to say sorry it’s not me, being an ahold.
 

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undergrove

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I've been running this -20 offset for like a month now. I have to say it has improved things a lot.

However, I do miss it starting off at the posted speed limit when I engage TACC, not a huge deal, but I do miss it.

It is not full proof. One thing I have learned is that when the car does say slow down aggressively, say by a mere 20 mph, it feels like it slammed on the brakes hard, maybe it did, but I think it feels worse than it really is.

I was driving home on a 120 mile trip the other day and I did have a couple phantom brakes. But each one seemed, albeit overly cautious and not something I would ever do, but there were reasons for them. I'm ok with that.

In one case, I was zooming into a toll booth quicker than I normally do (I usually slow way sooner than 95% of the other drivers). I typically cancel TACC early to get good regen. But there was a car jockeying for a slot so I kept my speed up a little longer (more in line with other cars). More so to communicate to the other driver my intent for my lane choice, nothing aggressive. Out of the blue the car aggressively slowed down. Crap, I'm in a 35 mph zone doing 60. So if it's a large offset it will still change speed. Now it might have seen the toll booth as an obstacle. It was still a fair distance away. But it had good reason to slow down. Nothing on the screen, no warnings.

Another case was a Semi pulled over on the shoulder. I immediately looked down at the screen after it "Phantom Braked" and the Semi was not showing. There was no reason to brake, but I can see why it might have been cautious. Again no warning, no beep. Semi did look "out of place".

One other case was cars jockeying in lanes ahead but not in my lane.

Before the -20 Offset I used have so many cases of phantom braking with no clear reason at all, expect an overpass ahead (and sometimes not). Since doing the -20 offset that has not happened once.
I'm tempted to turn that back to normal (0 offset) to see how it's doing.
I just completed a 120 mile round trip into L.A. on a familiar route, using for the first time Firmware 28.2. I experienced no episodes of phantom braking with two exceptions.

The first was the usual place in the perpetual construction zone on the I-5 around Santa Clarita where the car thinks the speed limit drops from 65 to 40 for a few hundred feet--this area has undergone so many changes in the last year that I do not drive it at night even without Autosteer, because you never know what you might encounter--no wonder the Tesla might be confused. It is only one specific spot.

The second was a brief slight slow down on a rural 4 lane undivided highway--not what I would normally call braking, but there were no other vehicles anywhere nearby. This road was being repaved for most of the last year and was intermittently under lane and speed limit restrictions. Maybe our Teslas have a memory of these things and remain extra cautious for a while ; ).

We have been using the -20 setting for about 9 months, and true phantom braking has been pretty rare and getting rarer.

On my first long drive on 28.2 in moderately heavy traffic in L.A. even caution braking seemed rarer and much smoother. Auto lane changes seemed smoother, more patient, and smarter.

This is very preliminary, but consistent with our impression that each major update gets gradually better. I am interested to see if others have similar impressions of 28.2.

It is not Full Self Driving, but with TACC, Autosteer, or NOA we feel much safer with the combination of our eyes and the Tesla's.
 

MelindaV

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The second was a brief slight slow down on a rural 4 lane undivided highway--not what I would normally call braking, but there were no other vehicles anywhere nearby. This road was being repaved for most of the last year and was intermittently under lane and speed limit restrictions. Maybe our Teslas have a memory of these things and remain extra cautious for a while ; ).
I think the second example (maybe your first example too) would be explained by the prior drivers slowing in those specific areas and Tesla recording that as the 'real life' speed limit for those areas.
My freeway interchange (from a 65MPH to a 55MPH freeway) has a pretty sharp right hand curve while still within the 65MPH section and AP will drop to 50 for about 20-30 yards before jumping back up to the new 55MPH speed limit (showing on the display the correct 65/50 speed sign). Most every day, the other traffic is at or below 50MPH anyway, so it is not noticeable, but when going thru the interchange later at night or when there is little traffic, it is abrupt and wacky. (IOW, I have my foot over the accelerator ready to keep it at the cruising speed). Over the last 10+ months of driving the car, it has always dropped to 50 at that one spot, but over time, where those 20-30 yards of reduced TACC speed happens has shifted a little backwards or forwards on the interchange ramp - so does seem dynamic per historical data Tesla is collecting. (and again, in normal traffic, or when following someone that maybe isn't familiar with the ramp or someone with a less stable car it is very normal to be traveling at 50mph at that spot).
 

MelindaV

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How does the relative speed limit affect Phantom Braking.
I've always had mine set to +0 and rarely have any phantom braking. Because of my normal traffic, I am almost always going under the set speed as well - if that makes any difference.
Since some are noticing setting their relative speed significantly under the speed limit, then tapping it up to the speed they want to go, gets fewer phantom braking issues, there may be something to the set speed.
 

Madmolecule

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To worn other drivers I have ordered some "Autopilot on Board" signs from Alibaba. It we be a couple weeks before I have them to ship. But I listed them on ebay. I have the for $8 with free shipping
, but I am certainly willing to take less if interested.

Ebay listing

suction-car-sign-reflective-magnetic-sticker-baby-jpg.28220
 

Madmolecule

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Its not and excuse at all. But when my car does stupid stuff, I dont want to get shot. (I live in the south - shot first ask questions later). Hopefully FSD will be an excuse, but other drivers have no idea if I had a sign that said FSD on board. Non-Tesla owners aren't aware that Elon keeps changing the definition of autopilot. But thanks for straitening that out for me.
 

undergrove

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How does the relative speed limit affect Phantom Braking.

In TACC or Autopilot, with the Speed Limit set to Relative and the Offset to 0, the Tesla will adjust your speed to what it perceives to be the posted speed limit (indicated in the upper right of the area of the screen with the car avatar). If you engage TACC or Autopilot while going slower, it will immediately speed up to the perceived limit.

If you raise or lower the Offset, the Tesla will adjust speed to the perceived limit plus or minus the Offset.

The -20 setting is a special case. When you engage TACC or Autopilot it becomes like a traditional cruise control. It sets and maintains the speed at which you engage. It does not change the set speed as the speed limit changes. You have to do that manually with the right thumb wheel.

One theoretical cause of true phantom braking, which occurs when there is no traffic to cause a caution reaction, is that the Tesla briefly thinks the speed limit has changed--sometimes due to a slow surface street on an over- or underpass. If you look at your screen quickly enough, you can see it change the limit--generally only for a few seconds.

The -20 setting will generally eliminate this kind of sudden slowdown. There still seem to be a few specific locations where there is a persistent brief slowdown for no apparent reason, such as what MelindaV and I have described. These happen even with the -20 setting, but I have found them to be quite rare.

What I would call "Caution Braking," when the Tesla is clearly reacting to surrounding traffic or objects, is not affected by the -20 setting, but I think this has improved steadily with each major firmware update.

My initial impression of 28.2 is that it is significantly smoother and smarter in all maneuvers on TACC, Autopilot, and NOA. My last drive into L.A. was impressive.
 

undergrove

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Its not and excuse at all. But when my car does stupid stuff, I dont want to get shot. (I live in the south - shot first ask questions later). Hopefully FSD will be an excuse, but other drivers have no idea if I had a sign that said FSD on board. Non-Tesla owners aren't aware that Elon keeps changing the definition of autopilot. But thanks for straitening that out for me.
I think MelindaV's point is that Autopilot/NOA is not Full Self Driving. It is not as good as a skilled alert human driver and is not represented as being so.

However, I feel that with my own eyes and all of my Tesla's eyes and sensors, I am much safer than driving without. It has made driving much less stressful and more enjoyable. Nevertheless, especially in complex situations, I always feel I need to be ready to take over at any time.

Autopilot/NOA is far from perfect, but it continues to amaze me how far it has come in less than a year,
 

Madmolecule

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I got it. I have teslas. They warned me all the time to pay attention and keep my hands on the wheel. I have driven cars before. I understand the liability. But the auto pilot does not drive the way most people drive all the time. It is too considerate sometimes and other times just stupid. When it reacts to other cars or highway conditions I find it sometimes confusing to the other drivers. I don’t know a way to react quick enough to phantom breaking at 80 miles an hour. I don’t fee, I was ever at risk of wrecking but I was concerned about the guy behind me running into me and thunking I had done it on purpose for some reason.
 

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In TACC or Autopilot, with the Speed Limit set to Relative and the Offset to 0, the Tesla will adjust your speed to what it perceives to be the posted speed limit (indicated in the upper right of the area of the screen with the car avatar). If you engage TACC or Autopilot while going slower, it will immediately speed up to the perceived limit.

If you raise or lower the Offset, the Tesla will adjust speed to the perceived limit plus or minus the Offset.

The -20 setting is a special case. When you engage TACC or Autopilot it becomes like a traditional cruise control. It sets and maintains the speed at which you engage. It does not change the set speed as the speed limit changes. You have to do that manually with the right thumb wheel.

One theoretical cause of true phantom braking, which occurs when there is no traffic to cause a caution reaction, is that the Tesla briefly thinks the speed limit has changed--sometimes due to a slow surface street on an over- or underpass. If you look at your screen quickly enough, you can see it change the limit--generally only for a few seconds.

The -20 setting will generally eliminate this kind of sudden slowdown. There still seem to be a few specific locations where there is a persistent brief slowdown for no apparent reason, such as what MelindaV and I have described. These happen even with the -20 setting, but I have found them to be quite rare.

What I would call "Caution Braking," when the Tesla is clearly reacting to surrounding traffic or objects, is not affected by the -20 setting, but I think this has improved steadily with each major firmware update.

My initial impression of 28.2 is that it is significantly smoother and smarter in all maneuvers on TACC, Autopilot, and NOA. My last drive into L.A. was impressive.
That is exactly my understanding as well.

Was your 28.2 drive with -20 or not?
 

undergrove

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That is exactly my understanding as well.

Was your 28.2 drive with -20 or not?
Yes. Because we live in farm country, all of our trips involve driving on winding two lane country roads to get to a city or highway. Autopilot works very well on these roads but the default speed is 55. Due to critters and farm machinery, etc. it is generally not safe to drive that fast, especially at night. When engaging TACC or Autosteer it was too annoying to have to quickly whip the thumb wheel down to keep the car from jumping to 55, so we leave it at -20.

A side benefit is that we seem to have missed out on a lot of the phantom braking that many have been experiencing.

I think on a long trip on major highways we might put the offset back to 0.
 

undergrove

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I got it. I have teslas. They warned me all the time to pay attention and keep my hands on the wheel. I have driven cars before. I understand the liability. But the auto pilot does not drive the way most people drive all the time. It is too considerate sometimes and other times just stupid. When it reacts to other cars or highway conditions I find it sometimes confusing to the other drivers. I don’t know a way to react quick enough to phantom breaking at 80 miles an hour. I don’t fee, I was ever at risk of wrecking but I was concerned about the guy behind me running into me and thunking I had done it on purpose for some reason.
At 80 mph reactions have to be much quicker, so it is not surprising that the Tesla might be much more jerky. I wouldn't trust my own reactions at that speed.

We almost always drive at or below the posted limits--45 to 65 mph--slower in heavy traffic. Our recent experience has been that the Tesla generally reacts pretty smoothly and intelligently at those speeds. There are still edge cases where we have to intervene.

We also have the follow setting at 6 or 7, which seems to give the Tesla more time to react. I know many people feel they can't use that setting in their driving conditions, but it has worked fine for us in Ventura and L.A. Counties.