Autopilot-to-TACC (autopilot cancel) bad interaction

[Tazman]

It should disable bot. Downside of an inadvertent crash>upside of additional convenience risk of sudden deceleration notwithstanding. As a minimum, hold speed constant vs increase.

 

[KZKZ]

I wonder what others here think about what happens when cancelling autopilot while speed restricted on a non-divided highway.

Example:

1. I am traveling at 60MPH with autopilot engaged on a 2-lane road.
2. I enter a 40MPH zone as I pass through a small residential area, and the car displays the speed-restricted message as it slows to 45MPH.
3. I turn the wheel to avoid a road surface defect (e.g. pothole) or because Autopilot deals poorly with a sharp curve.
4. The car leaves autopilot but remains in TACC mode, and accelerates to the full 60MPH speed that was set in step 1.

I understand why this happens -- because there is no speed restriction for pure TACC, but there is one for autopilot -- but this strikes me as a very, very bad interaction of the speed-restriction and TACC features. The car should, I believe, never accelerate automatically when a driver assistance feature is disengaged.

It needs to retain a little more state: when it transitions from a speed-restricted autopilot condition into TACC-only, it needs to reset the TACC speed to the restricted speed. Anything else can cause acceleration that from the driver's point of view is sudden and unexpected -- and that's not good.

Do others agree?

Note that though one can train oneself to always cancel autopilot with the brake rather than the steering -- and I am a staunch advocate that autopilot-assisted driving is a skill that itself requires the driver to learn and practice a number of new habits for safety, this among them -- it is also possible to cancel autopilot accidentally by bumping or too firmly nudging the wheel.

I don't know whether this interaction also happens in the case of the flashing red "TAKE OVER IMMEDIATELY" e.g. when autopilot loses the lane line on a sharp curve. If it does, that'd be particularly bad. There's a section of road near here where the speed limit drops from 55 (straight as an arrow, too) to 30 with a series of very sharp curves where autopilot frequently requires a driver takeover. I never let autopilot enter that area without manually reducing the set speed precisely because I'm worried about this interaction; but I live here, so I know! A driver from another area could be surprised.

Thanks for the detailed descriptions of this scenario. I can see where this could catch the driver off guard.

 

[sloopee]

I totally agree with this. Sometimes when it says AP unavailable on this road so it just loses TACC but keeps autosteer on and i decide to take over autosteer by instinctively turning the wheel the car would leap to the TACC speed previously set.

 

[TaoJones]

I totally agree with this. Sometimes when it says AP unavailable on this road so it just loses TACC but keeps autosteer on and i decide to take over autosteer by instinctively turning the wheel the car would leap to the TACC speed previously set.

Am surprised that they've let this one out as, ostensibly, a deferred defect.

Wonder when they'll fix it... I've encountered similar behavior multiple times (Autosteer drops off and the car speeds up to a previously-set higher TACC speed limit). It's not good.

See, if we had release notes with each OTA release, maybe we'd know. But that would be too easy.

I recall trying to report it a couple of times via the verbal "Bug report" command, and each time was without connectivity. Ran into that a lot this past series of road trips. Then I forgot to email them about it when I got back, but clearly this is a big enough miss that they a) have to know about it, b) must have encountered it during beta testing, c) considered it an edge case, and d) into the bucket it went for prioritization for a future fix.

In a perfect and transparent world, we'd get a vote (not a majority vote - just a vote) via crowdsourcing with regard to owner sentiment for fixing whichever bugs there might be. Clearly, priority 1s and 2s are going to get fixed without any help needed whatsoever from us, but there's always a bunch of lower-priority grab bag stuff for which maybe Tesla would appreciate some owner input with regard to what to fix next. Today, that happens via phone calls and emails and audio bug reports, but it's hardly at the level of anything that would resemble transparency or comprehensiveness.

 

[Big-Al]

I've noticed this problem too and find it disconcerting when I turn off auto-steer and the TACC remain engaged, causing the car to surge in speed. I've found that the most effective solution is to push back once on the autopilot stalk, which disengages both the auto-steer and the TACC.

 

[Chopr147]

I wonder what others here think about what happens when cancelling autopilot while speed restricted on a non-divided highway.

Example:

1. I am traveling at 60MPH with autopilot engaged on a 2-lane road.
2. I enter a 40MPH zone as I pass through a small residential area, and the car displays the speed-restricted message as it slows to 45MPH.
3. I turn the wheel to avoid a road surface defect (e.g. pothole) or because Autopilot deals poorly with a sharp curve.
4. The car leaves autopilot but remains in TACC mode, and accelerates to the full 60MPH speed that was set in step 1.

I understand why this happens -- because there is no speed restriction for pure TACC, but there is one for autopilot -- but this strikes me as a very, very bad interaction of the speed-restriction and TACC features. The car should, I believe, never accelerate automatically when a driver assistance feature is disengaged.

It needs to retain a little more state: when it transitions from a speed-restricted autopilot condition into TACC-only, it needs to reset the TACC speed to the restricted speed. Anything else can cause acceleration that from the driver's point of view is sudden and unexpected -- and that's not good.

Do others agree?

Note that though one can train oneself to always cancel autopilot with the brake rather than the steering -- and I am a staunch advocate that autopilot-assisted driving is a skill that itself requires the driver to learn and practice a number of new habits for safety, this among them -- it is also possible to cancel autopilot accidentally by bumping or too firmly nudging the wheel.

I don't know whether this interaction also happens in the case of the flashing red "TAKE OVER IMMEDIATELY" e.g. when autopilot loses the lane line on a sharp curve. If it does, that'd be particularly bad. There's a section of road near here where the speed limit drops from 55 (straight as an arrow, too) to 30 with a series of very sharp curves where autopilot frequently requires a driver takeover. I never let autopilot enter that area without manually reducing the set speed precisely because I'm worried about this interaction; but I live here, so I know! A driver from another area could be surprised.

I plan on doing all sorts of experiments with my S when it comes in. One ride I take maybe 2-3 times a month is the Taconic State Parkway. I actually love that ride but many people are too nervous to take it. Keeps the traffic low I am very curious how the AP will handle that pkwy. 55 MPH quickly goes down to 40 mph with several hairy turns. Being from NY you are probably aware of the TSP. At one point the curve makes a complete U-turn around the mountain and if S/B downhill. Tesla regen. or not you will be hitting the brakes. At that location I can see it being very dangerous to have the car accelerate on it's own.

 

[xkwizit]

I found this thread very interesting especially the different driving habits. When avoiding something I wouldn't normally do it at speed I am traveling. My instinct is to press the brakes and then swerve. Which results in both TACC and AS canceling out. But I do see the point that @somejoe777 and others are saying and may have experienced the unexpected acceleration. I agree that moving the steering should also equate to user taking over and thus cancel TACC as well.
@Chopr147 - when the car detects a curve it slows down to a reasonable speed to negotiate the curve if the curve has been built with enough width. However very sharp turns like 90degree are something that the car cannot handle.

 

[KZKZ]

Thanks for the further clarification on this interaction. The more I hear the description of the issue the more I wonder how much thought Tesla really put into AP before releasing it to the general public. This type of design issue really should have been picked up through their own testing.

 

[thimel]

I personally like it the way it is. I grap the wheel when auto steering misbehaves much more often than I cancel TACC. When I know I want to cancel both e.g. when exiting the freeway, I lightly press the accelerator to minimize regen and then push the cruise control stalk away from me to disengage both.

 

[fren]

1. I am traveling at 60MPH with autopilot engaged on a 2-lane road.
2. I enter a 40MPH zone as I pass through a small residential area, and the car displays the speed-restricted message as it slows to 45MPH..

i thought with autopilot the car would not change it's speed ( 60 to 40 mph ), thought it was your responsability to reduce manually?
other question : in France on highway speed is limited to 130 km/h and if raining 110km/h , if autopilot is on and rain detected will it slow from 130 o 110 too ?
thx,

 

[Pruitt]

My thought is that, when autosteer is deactivated when TACC is in a speed-limit-following mode, the system gives you the option to resume non-restricted speed, perhaps by flipping the TACC lever towards you once. Otherwise it stays in speed-limit-following mode.

As far as that goes, I'd like to be able to set TACC into a speed-limit-following mode for any road, regardless of autosteer engagement.

 

[rhumbliner]

As far as that goes, I'd like to be able to set TACC into a speed-limit-following mode for any road, regardless of autosteer engagement.

I'll second that suggestion. To me it's much more logical to think of these driving aids as two separate capabilities: speed-keeping and lane-keeping. TACC should always follow posted speed limits regardless of the state of auto-steer.

Lately I've been driving thru a lot of small towns and I use TACC to just follow the traffic in front of me -- slowing down thru town and speeding up on the other side. But it's really disconcerting to have the car I front of me slow down to turn off the highway and have MS suddenly accelerate to 55 mph in a 30 mph zone.

 

[BQst]

I turn the wheel to avoid a road surface defect (e.g. pothole) or because Autopilot deals poorly with a sharp curve.

The car leaves autopilot but remains in TACC mode, and accelerates to the full 60MPH speed that was set in step 1

Agree. Have had this exact experience as well. Wish tacc automatically adjusted to match the speed autopilot was maintaining?

Ben