Sudden slowing on AP at highway speed

[kiwi]

I still get phantom braking... although the causes do seem to be changing over time as AP develops.
Braking used to happen often under bridges (shadows), but that hasn't happened for a long time.
Braking used to happen on empty roads and in busy traffic during the day, and it still does that
(its quite a scary event in busy traffic).
Some people suggested reducing following distances from "4" to "3". I've tried that,
but it still happens.

I don't do long trips with AP very often, but it usually happens at least once on every trip,
so its still pretty regular.

 

[rgedad]

I have a June 2018 MX. I have had this happen about 5 times since we have had the car.
I travel at Speed limit up to +5 and have the follow-on distance set to 6 (Very conservative - Old fart distance).
Seems to be most prevalent when on a light colored roads (Concrete) with a strong overhead sun casting a very defined shadow under the bridge ahead. Light to no traffic. I live in Texas so lots of days with clear skies and light colored roads.
I now assume the car is just afraid of Trolls who are living under the bridges when it happens, and just kick the accelerator and move on. Biggest issue is calming down my wife when it happens - she is still quite nervous about the Autopilot feature - so I never use it with her in the car unless on the interstate and in the center lanes. Never worry about the people traveling behind me - nothing I can do about fools driving too close in any case.

 

[Tony17MXred22”]

So I just drove 1200 miles from Portland To Palm Springs. I used the AP feature a lot and I had zero situations with braking unexpectedly. I think Tesla maybe improving this situation. Now that I have 15,000 miles and a year under my belt on AP. I guess i pretty much know when to use AP and when not to use it.

Thanks
Tony

 

[gnuarm]

Yes, I have had similar braking, but not so hard usually. I've never had it seem to lock up the brakes, just a hard slow down, usually just for a moment. I think maybe once it slowed so much I got worried of cars behind me. Mostly I'm worried about trucks. You can say they are responsible for following at a safe distance, etc. But if they slam into you and you die, Tesla will claim you didn't have your hands on the wheel for six seconds before the accident and you will still be dead. Heck, driving on cruise control I've had trucks so close behind me I thought they were trying to open my trunk! The X keeps speed perfectly while the truckers go a lot faster down hill.

 

[Aieukl378]

When this happens send a Bug Report to Tesla: voice command/"bug report braking"

 

[Jonathantuba]

Phantom braking does occur occasionally I find, but it is not that violent and I step on the power if it does - not the brake - and that cancels.

 

[jboy210]

AP saved my bacon yesterday. Some idiot got on the freeway in front of me. He drifted through my lane to the center lane to my left. Since he cleared the lane, AP accelerated toward the set speed.

After 5 seconds I was getting closer to this guy's truck. Then he realizes that he wants to be in my lane. He cuts over in front me without looking. AP hits the brakes hard, and turns the car right and part way on to the shoulder. After a second or so, AP realizes the guy has completed cutting me off, and gracefully steers to the left and behind this idiot. Only then do I notice that through all of this, he never turned off his left turn signal from getting on the freeway!

 

[doghousePVD]

EAP prevented an accident for me a few days ago. A sports car in the left lane veered very sharp right across my lane trying to make a missed exit. Car slammed on the brakes hard, went from 75 to 40 instantly. Then after the sports car crossed my lane, my car hard accelerated back to 75. I think I maybe could have prevented the accident, but probably not. The EAP paid for itself in two seconds. I am very impressed.

 

[gnuarm]

AP saved my bacon yesterday. Some idiot got on the freeway in front of me. He drifted through my lane to the center lane to my left. Since he cleared the lane, AP accelerated toward the set speed.

After 5 seconds I was getting closer to this guy's truck. Then he realizes that he wants to be in my lane. He cuts over in front me without looking. AP hits the brakes hard, and turns the car right and part way on to the shoulder. After a second or so, AP realizes the guy has completed cutting me off, and gracefully steers to the left and behind this idiot. Only then do I notice that through all of this, he never turned off his left turn signal from getting on the freeway!

You could say the AP got you into a mess before making up for it. I think the AP accelerates a bit too fast in situations like that. I'd like it to accelerate more gently when space opens in front of you. It also seems to do a poor job of seeing what's ahead and breaking too hard to avoid banging into things such as cars in your lane. As long as the car is in front of you within some distance the whole time it does fine. But once the traffic gets further out and they have to slow or stop, they aren't seen very quickly at all.

 

[ajdelange]

I agree that the car accelerates to quickly when traffic in front gets out of the way or starts to accelerate when a clump breaks up. My objection stems not only from the fact that I'm now a timid old fart but that she sucks 75 kW when doing this.

 

[jboy210]

I agree that the car accelerates to quickly when traffic in front gets out of the way or starts to accelerate when a clump breaks up. My objection stems not only from the fact that I'm now a timid old fart but that she sucks 75 kW when doing this.

I am old, and that acceleration is about all the excitement I get some days!

 

[kiwi]

I am old, and that acceleration is about all the excitement I get some days!

Sudden braking provides all the excitement I could ever want.

 

[gnuarm]

I am old, and that acceleration is about all the excitement I get some days!

I have had to cancel the sudden acceleration more than once because it was accelerating into a dangerous situation. Auto pilot seems to have very little understanding of what is actually in front of the car. If one car moves out of the way and another is only a little further down the road, it will not see the further car and accelerate into a stopped car even. Or through an intersection where it should be slowing anyway.

You have to keep a close eye on the auto pilot. There are now a couple of people who can't tell you that since they are no longer with us. That's something I worry about. It is very easy to get too wrapped up in mucking with the heating controls or something else inside the car rather than paying close attention to the road.

 

[jboy210]

I have had to cancel the sudden acceleration more than once because it was accelerating into a dangerous situation. Auto pilot seems to have very little understanding of what is actually in front of the car. If one car moves out of the way and another is only a little further down the road, it will not see the further car and accelerate into a stopped car even. Or through an intersection where it should be slowing anyway.

You have to keep a close eye on the auto pilot. There are now a couple of people who can't tell you that since they are no longer with us. That's something I worry about. It is very easy to get too wrapped up in mucking with the heating controls or something else inside the car rather than paying close attention to the road.

What do you the following distance sensitivity set to on your car? This is setting you adjust by twisting the knob on the end of cruise/autopilot stalk. I find 1 and 2 being too close for me and it feels like it is runs up the back of cars in front. So I use 3. The AP uses this setting when resuming following distance. And since a Tesla accelerates right now, it can seem jarring to see the rear of a car in front coming up quickly.

And I know what you mean by getting wrapped in the AP controls. I am private pilot/owner and you see this in flying. When you have a lot of complex systems you need to develop procedures for not getting wrapped up in the automation or communications. Trained airline pilots have flown perfectly good airliners into the ground because they were preoccupied with a light on the panel being flaky, or into the side of mountains because they entered an code incorrectly into the AutoPilot.

 

[mvgenabe]

Iemand met een model x die mij uit de nood kan helpen?
0496 02 17 59

 

[mvgenabe]

Somebody in Belgium with model X?

 

[mvgenabe]

Hi! Is here somebody with a model x in Belgium to help me? We need a tesla model x to pull something on an event. Only electrical cars allowed.. very urgent. Many thanks to help me...

 

[Batt Car]

So I have had the breaking happen twice and I figured out what caused it for me. It was glare on the highway (sun glare of course). I had time to circle back and confirm it. Basically the cameras see the glare and it must appear like something is directly in front of the car so it starts rapid deceleration. Ran it a couple times with no cars around me and each time the behavior was the same.

 

[gnuarm]

What do you the following distance sensitivity set to on your car? This is setting you adjust by twisting the knob on the end of cruise/autopilot stalk. I find 1 and 2 being too close for me and it feels like it is runs up the back of cars in front. So I use 3. The AP uses this setting when resuming following distance. And since a Tesla accelerates right now, it can seem jarring to see the rear of a car in front coming up quickly.

Mostly I set it to 7 and close it up to 5 or maybe 4 in crowded conditions. I'd rather lose position to a few jerks than to sacrifice much safety. 1 is WAY too close for me.

And I know what you mean by getting wrapped in the AP controls. I am private pilot/owner and you see this in flying. When you have a lot of complex systems you need to develop procedures for not getting wrapped up in the automation or communications. Trained airline pilots have flown perfectly good airliners into the ground because they were preoccupied with a light on the panel being flaky, or into the side of mountains because they entered an code incorrectly into the AutoPilot.

When considering the controls in the car I often think of pilots. I know the airlines, airplane makers and FAA spend a lot of effort considering these issues when they try to make the planes safer.

One that messed me up several times today is the similarity between the turn signal stalk and the AP control. I would want to take the AP off because someone was tailgating me while I was in the left lane and I needed to drop back behind someone in the right lane to let the tailgater pass. I would accidentally push the turn signal stalk forward lighting up my high beams. Or make any of several other similar mistakes confusing the two. It didn't help that I was nearing the end of a 12 hour driving day. Way too many long charging stops for a 500 mile trip. We were combining charging with socializing which meant the long stops were not needed so we still had to make long charges where they were needed and still failed to be able to skip a charger. In fact this trip is starting to convince me the current state of EVs just plain make them unsuitable for trips.

Anyway, I think the AP stalk should be on the other side of the steering wheel or maybe some other type of control.

These problems aren't just in airplanes. I recall reading that the head of Daimler-Benz learned a couple died because the husband confused the windshield wiper and the headlight controls turning off the headlights. I remember cars at that time had identically shaped controls on opposite sides of the steering wheel for these two functions. Having the similarly operating turn signal and AP stalks side by side seem to be an equally poor choice.

 

[Rossy]

We see this in Oregon Eastbound on HWY26 at the Helvetia overpass. Once westbound towing a trailer.
But two weeks ago heading West from Oregon coast at NIGHT the car slammed on the brakes while cruising at 55-60mph. We all felt like minor whiplash after that one. Recommendation...keep foot near the gas.

I was driving south on i5 in Washington state two weeks ago going 70-75mph on autopilot with navigation on and suddenly the brakes locked up and the car was coming to a sudden stop. I hit the brakes my self and then the accelerator as quick as I could. I looked in my rear view mirror and luckily there was nobody following me. Wow that was close. So I told the guys at my service center in Portland Oregon about what happened and he said “ya we have heard that happens at times”. I asked him if I had been rear ended would Tesla stand behind the accident? He said no that the autopilot with navigation is beta status. He said I would have to give him the exact location on i5 and he would pass it onto engineering and they would have to go in and change the programming in the system to tell the cars not to jam the brakes at that location. That did not sound very reassuring to me.

I also notified Tesla corp from my Tesla account and they responded with a boiler plate statement that was not very satisfying. I love my car and its the best automobile I have ever had. I was counting the other day and I have owned more than 50 cars so far and this is the best. However If I were to be killed in an accident because of some programming error that would be tragic. I love the autopilot and have driven 14,000 miles in ten months using a lot of autopilot. This is the second time the car did this brake locking up situation. The first time it was just for a split second and then then car recovered and accelerated on its own.

So I think I know why the car is doing this. I would like to advise others to be aware of this situation. I believe the car thinks its running into a wall when this braking accrues. What I believe is happening is when I am driving on a downhill interstate with an overpass in the middle of the hill the car sees the dark background of the hillside and when the overpass comes into play is when the car gets close to the overpass and the car thinks because its a solid straight line on the horizon / overpass it thinks there is a wall in front of the car and slams the brakes on.

Has anybody else had this happen?

Thank you
Tony