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Automatic Emergency Braking

Sep 4, 2020
5
0
Vancouver Canada
In Autopilot, my car will slow and stop according to the car in front as expected. However, I feel like the automatic emergency braking feature is not working unless I'm in Autopilot. I'm not game to really "test" it, but the vehicle has never shown any inclination to stop itself when just driving manually. I expected that it would always be looking to avoid a frontal collision, even when not in Autopilot. Is my expectation wrong?

Note: The car also seems really poor at seeing fixed objects, even when in autopilot. I've had to brake hard for a stopped line of traffic on a few occasions, even when in autopilot. These have been times when the vehicle in front has stopped by the time the car "sees" it.

Seems to me like the car should/could be set up to simply not allow me to drive into stuff. It seems far from that right now.
 

HenryFarkas

Member
Jun 30, 2020
109
69
Maryland, US
On the other side of the same issue, when I'm in Autopilot, the M3 sometimes brakes for no apparent reason. This has been referred to in the forum as phantom braking, and I, too can attest that it happens.
 
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Sep 4, 2020
5
0
Vancouver Canada
On the other side of the same issue, when I'm in Autopilot, the M3 sometimes brakes for no apparent reason. This has been referred to in the forum as phantom braking, and I, too can attest that it happens.

I get that too from time-to-time. I can usually figure out why the car has slowed, what it has detected, but it's just that I feel it has overreacted. But yeah, very occasionally there seems to be no reason at all. The vehicle is getting better at that, though. The smoothness of lane-keeping when in autopilot has also improved over time. It used to be a bit "frantic"..
 

HenryFarkas

Member
Jun 30, 2020
109
69
Maryland, US
While we're writing about smoothness of lane-keeping, which, I agree, is improving, we should mention smoothness of stopping for red lights and stop signs. Smoothness of slowing down and stopping was terrible in June (of this year) when I bought my M3. It has improved lately, although that might be due to my changing the power setting to "chill." It's still not as smooth as an average human driver. Stopping for a traffic signal or stop sign should be smoother than a human driver could possibly accomplish, and it should be consistently smooth every time..
 
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UncleCreepy

Member
Mar 29, 2020
252
402
Lunenburg, ON
When you tried this, how close did you come to an actual collision?
I was driving manually. The battery was almost full and I had a car stopping in front of me. Since the regen was reduced, I didn't get as much deceleration as I was hoping for. Not wanting to use the friction brake, I kept my foot over the brake pedal without actually braking. The plan was only to brake if it was absolutely necessary. Usually I keep about one car length between myself and the car in front of me, but this time I knew I'd get as close as maybe 3 feet. And this is when the AEB kicked in and slammed the brakes.

I knew I wasn't going to hit the other car, but apparently the sensors weren't so sure.

Anyway, the collision warning triggers a lot earlier than AEB. By the time it triggered, my speed was maybe 6 mph or 10 kph. I can't say how it is at higher speeds and I have no intentions finding out.
 

andy92782

Member
Oct 14, 2018
272
410
Southern Calfornia
On the other side of the same issue, when I'm in Autopilot, the M3 sometimes brakes for no apparent reason. This has been referred to in the forum as phantom braking, and I, too can attest that it happens.

This happened to me yesterday. Second time in two weeks. It always seems to happen just before driving underneath an overpass. The guy behind me almost rear ended me, and he was sure to stay WAY back after it happened...

I don't trust AP anymore.
 

HenryFarkas

Member
Jun 30, 2020
109
69
Maryland, US
It might be caused by shadows across the road. On my local street, where there are no lane lines, I sometimes get phantom braking when I'm passing a parked car. I've stopped using AP on roads without painted lane markings. It usually works pretty well on roads with clear lane markings.
 

andy92782

Member
Oct 14, 2018
272
410
Southern Calfornia
It might be caused by shadows across the road. On my local street, where there are no lane lines, I sometimes get phantom braking when I'm passing a parked car. I've stopped using AP on roads without painted lane markings. It usually works pretty well on roads with clear lane markings.

Whatever the cause, it shouldn't be doing it. Definitely not this late in the game. Freeway overpasses are everywhere. I'm not going to use the system if it causes my nerves to tense up every time I approach one doing 70+ mph.

EDIT: There went ~$6K down the drain (I purchased Enhanced AP back in the day...).
 

HenryFarkas

Member
Jun 30, 2020
109
69
Maryland, US
Whatever the cause, it shouldn't be doing it. Definitely not this late in the game. Freeway overpasses are everywhere. I'm not going to use the system if it causes my nerves to tense up every time I approach one doing 70+ mph.

EDIT: There went ~$6K down the drain (I purchased Enhanced AP back in the day...).
Try it again after the next OTA update. Autopilot improves every so often. Every time there's an OTA software update, they tell you what the update addresses. If it addresses Autopilot, then they may have improved the phantom braking situation. I purchased my M3 in June with FSD. The phantom braking situation has improved since then, but it's not yet gone. The software will probably improve some more. It will have to improve if they expect people to send their Teslas out to work for a living without any human driver.

Frankly, I'm not planning to send my car out to work for me. The software update that I'm looking forward to is the one that will let me use my car as a backup source of electricity for my house during a power outage. That should be much easier for Tesla to accomplish.
 

Mash

Supporting Member
Supporting Member
Nov 10, 2019
985
715
Prague
Frankly, I'm not planning to send my car out to work for me. The software update that I'm looking forward to is the one that will let me use my car as a backup source of electricity for my house during a power outage. That should be much easier for Tesla to accomplish.
I have to disappoint you - there is no hardware on your car to let electricity flow from the car to outside. In fact - there is a hardware that blocks that by design. It impossible to do by software update. Charging circuit would have to be redesigned and exchanged.
 

HenryFarkas

Member
Jun 30, 2020
109
69
Maryland, US
I have to disappoint you - there is no hardware on your car to let electricity flow from the car to outside. In fact - there is a hardware that blocks that by design. It impossible to do by software update. Charging circuit would have to be redesigned and exchanged.
Actually, there is vehicle to grid (or home) capability just waiting for Elon Musk to turn it on. My guess is that it will work only with hardware attached to the house that doesn't yet exist, but according to the article below, Elon is planning to institute this feature.

Tesla quietly adds bidirectional charging capability for game-changing new features [Updated] - Electrek
 

HenryFarkas

Member
Jun 30, 2020
109
69
Maryland, US
The first time I read the above article in Electrek, it didn't have the video attached. Having already put the article up, I went back and played the video. It's a teardown of the power electronics. The guy doing the teardown comments that the electronics could be bidirectional with the replacement of a few parts, but as of the time the car in the teardown was manufactured, the power electronics were not bi-directional. Unfortunately, the video doesn't mention when that particular car was manufactured..
 
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Knightshade

Well-Known Member
Jul 31, 2017
12,858
19,095
NC

andy92782

Member
Oct 14, 2018
272
410
Southern Calfornia
My guess is vehicle-to-grid would only be possible today if an inverter was installed in the garage location. They could switch on the HVDC contactors (like while Supercharging) which could then power a "shore side" inverter.

But enough of that. This thread is about AEB and phantom braking, and with these latest releases, AP is unusable due to the high incidence of phantom braking.
 

Knightshade

Well-Known Member
Jul 31, 2017
12,858
19,095
NC
But enough of that. This thread is about AEB and phantom braking, and with these latest releases, AP is unusable due to the high incidence of phantom braking.


Weird... I've used it over 20,000 miles and can count on 1 hand the # of "phantom" braking incidences I've had.

This is almost exclusively on intended-use roads though, and (perhaps crucially for some incidences folks report) on interstates with correct speed limits in the database.

IIRC my AEB is set to late FWIW.
 
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