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Auto-Pilot Minimum Speed?

This just happened, so I haven't gone through and reviewed all of the details for the latest update which was downloaded yesterday. I'll review it today, but thought someone may have a quick reply.

I was driving down a local two lane road and wanted to try out of the auto-pilot. The road has the appropriate lines, but has a speed limit of 30 mph. When I engaged the auto-pilot the auto speed went immediately to 45 mph, causing me to disengage prior to reaching that speed. I tried again, driving at 30 mph when engaging and same thing - a jump to 45. Is there a minimum speed limit of 45 mph with the auto-pilot?
 

Max*

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You can control the speed of AP by click up (higher speed) or down (lower speed) on the AP stalk. Soft click = +/-1mph, hard click is +/-5mph to the nearest 5mph increment (i.e. you're doing 45mph and click hard down you'll be down to 40mph. you're doing 43mph, and click hard down, you'll also be down to 40mph)
 

mspohr

Well-Known Member
Jul 27, 2014
10,429
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This just happened, so I haven't gone through and reviewed all of the details for the latest update which was downloaded yesterday. I'll review it today, but thought someone may have a quick reply.

I was driving down a local two lane road and wanted to try out of the auto-pilot. The road has the appropriate lines, but has a speed limit of 30 mph. When I engaged the auto-pilot the auto speed went immediately to 45 mph, causing me to disengage prior to reaching that speed. I tried again, driving at 30 mph when engaging and same thing - a jump to 45. Is there a minimum speed limit of 45 mph with the auto-pilot?
That's odd. My experience has been that it sets the speed to 5 mph over the posted speed. In town, posted is 25 and it sets it to 30. Just out of town there is a short stretch of 35 and it ups it to 40. Then the road goes to 45 and it sets the speed to 50. I like the way this works since it avoids setting the speed too high... but your experience seems to be different.
 

Saghost

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Oct 9, 2013
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There's a minimum, but it is much lower than that (the documents say it won't engage below 18 mph unless it sees a car to follow.)

What are your Speed Assist settings on the car? You can set an absolute or relative to detected limit speed there which TACC will default to under some conditions.
 

jerry33

(S85-3/2/13 traded in) X LR: F2611##-3/27/20
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Mar 8, 2012
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Does anyone know how it works on streets with stop sign but when you're not following a car? Does it detect the stop sign and stop?
No. It doesn't detect stop signs or pedestrians. Right now it's really for highway use so you can somewhat skip the boring parts. Eventually, it will do all those things (although some suggest it will need new/updated hardware to do so).
 

Max*

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No. It doesn't detect stop signs or pedestrians. Right now it's really for highway use so you can somewhat skip the boring parts. Eventually, it will do all those things (although some suggest it will need new/updated hardware to do so).
EM (I think it was EM?) said that the current hardware generation can handle stop signs and traffic lights. And I believe it should be able to, at least in some sense handle them (at least stop, and have the user tell it to go once the intersection is clear).

Will they actually implement it? who knows.
 
So really it's a TACC/DRCC on steroids which added the auto steer function?

I am looking at either the MS or the '16 Prius 4 Touring with the Premium Convenience Package which has full speed dynamic laser cruise control (5-130mph), lane departure with steering assist (a slimmed down auto steer), and auto parking (parallel and perpendicular) so it sounds like I'm not really missing much for the price difference...

I saw some video of auto pilot on surface streets but it looks like you have to be following a car, otherwise the MS will get confused and (possibly?) won't stop at a light or stop sign if you're not following anyone? Can someone please confirm?
 

Max*

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So really it's a TACC/DRCC on steroids which added the auto steer function?

I am looking at either the MS or the '16 Prius 4 Touring with the Premium Convenience Package which has full speed dynamic laser cruise control (5-130mph), lane departure with steering assist (a slimmed down auto steer), and auto parking (parallel and perpendicular) so it sounds like I'm not really missing much for the price difference...

I saw some video of auto pilot on surface streets but it looks like you have to be following a car, otherwise the MS will get confused and (possibly?) won't stop at a light or stop sign if you're not following anyone? Can someone please confirm?

Autopilot is most useful on long drives. You get on the highway, and the car does it's thing. It stays in lane (some people take their hands off the wheel, some keep a light grip so that the highways which have a nag, won't nag you), it keeps distance, etc.

There are a lot of companies which offer similar "autopilot" capabilities (MB, Infiniti, Acura, etc.), supposedly Tesla's is slightly better than the competition.
 

Saghost

Well-Known Member
Oct 9, 2013
8,224
7,087
Delaware
I saw some video of auto pilot on surface streets but it looks like you have to be following a car, otherwise the MS will get confused and (possibly?) won't stop at a light or stop sign if you're not following anyone? Can someone please confirm?

In the current released version, Autopilot isn't paying any attention to Stop signs or traffic lights. Conveniently, it will stop in response to a car ahead stopping, but it isn't reading and responding to traffic signals or cross traffic/right of way, so if you use it in those environments you need to be watching everything just as much as if you didn't have AP, and be ready to intervene if necessary.

As far as I can see, there's no reason the current cars couldn't learn to stop at red traffic lights and stop signs with the next software update, but hardware limitations mean it'll require a human driver to tell the car when it can accelerate again (at least for the stop sign, and probably some traffic lights.)
Walter
 

Todd Burch

12-Year Member
Nov 3, 2009
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Smithfield, VA
There are a lot of companies which offer similar "autopilot" capabilities (MB, Infiniti, Acura, etc.), supposedly Tesla's is slightly better than the competition.

"Slightly better" is doing it a bit of a disservice, unless by "slightly better" you mean half the number of required lane intrusion interventions as the next best implementation, the only one with auto lane change, the only one that will park the car without a driver in the vehicle, the only one that shows 3 lanes of traffic on the display, potentially the longest time between nags (in general)...

I also use it on city streets all the time. Tesla's system might be the only one that will follow a car without lane markings or cross through an unmarked intersection without going haywire or disengaging...but I'm not sure about that.
 

Todd Burch

12-Year Member
Nov 3, 2009
8,325
35,182
Smithfield, VA
And to answer some of the questions:

There is no minimum speed for engaging autopilot. I do it all the time sitting stopped at a light. The only requirement is that you cannot have your foot on the brake when you want to engage it. Autopilot will follow traffic all the way down to a stop, and remain engaged while stopped or in bumper-to-bumper traffic. Having said that, TACC (the intelligent cruise control) has a minimum setting of 18 mph...meaning that if you are not following a slow moving vehicle, the car will not go slower than 18 mph. (So no luck setting it to 4 mph for a parade unless you want to follow another float fairly closely :)).

As for the "5 mph over" thing that people are referring to:

The driver assistance settings have a speed offset you can set, which indicates how much over or under the speed limit you want to travel by default. When the car knows the speed limit (using a combination of map databases and sign recognition using the camera--whichever gives the more conservative speed I believe), pulling on the CC stalk and holding it for a moment will set your TACC speed to the speed limit plus your desired offset. Moreover, on roads below a certain "class" (generally undivided and local roadways), autopilot will not drive more than 5 mph over the known speed limit. If the speed limit is unknown, it will not exceed 45 mph.
 

andrewket

Well-Known Member
Dec 20, 2012
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There's a minimum, but it is much lower than that (the documents say it won't engage below 18 mph unless it sees a car to follow.)

What are your Speed Assist settings on the car? You can set an absolute or relative to detected limit speed there which TACC will default to under some conditions.

Speed assist is only for warnings. These options have no impact on TACC. It's a common misunderstanding.
 

Todd Burch

12-Year Member
Nov 3, 2009
8,325
35,182
Smithfield, VA
Speed assist is only for warnings. These options have no impact on TACC. It's a common misunderstanding.

Actually, Saghost's description is accurate. As I wrote above, if the car knows the speed limit and you pull the stalk and hold, it will set the TACC speed to that speed limit plus the offset. And as Saghost said, in certain conditions engaging TACC with a quick pull will set the speed to the speed limit + offset.
 
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Max*

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"Slightly better" is doing it a bit of a disservice, unless by "slightly better" you mean half the number of required lane intrusion interventions as the next best implementation
http://www.caranddriver.com/feature...logy-of-semi-autonomy-and-test-results-page-6

Have you driven other cars, or is your opinion based on the article?

the only one with auto lane change

The auto lane change is somewhat of a gimmick, as it can't detect if there are cars behind you, and sometimes it doesn't want to change lanes when there are no cars. In addition, the auto lane change is very slow, if I need to change lanes normally (not if I'm driving out in the boonies, where there are very few cars), I'm often forced to disable AP, change lanes, and then re-enable AP.

the only one that will park the car without a driver in the vehicle

This is 100% a gimmick. When it can parallel park or perpendicular park with no one in the car, then I'll give them more weight.

the only one that shows 3 lanes of traffic on the display

I'll give you that.

potentially the longest time between nags (in general)...

Your hands should be on the wheel at all times, even with the Tesla (sure, no one does it), so the nags should be irrelevant ;).

I also use it on city streets all the time. Tesla's system might be the only one that will follow a car without lane markings or cross through an unmarked intersection without going haywire or disengaging...but I'm not sure about that.

I have it cross through intersections too, but it often drifts out of lane, and then has to correct when it sees the lane markings again. I don't use that feature often.


So I stand by my statement. We're not talking about day and night differences anymore. Tesla did a great job with the PR on AP. But there are many other companies who offer the technology at a slightly reduced maturity level.

If I said Tesla is only slightly better than other EV's, then you could call me crazy. As there are no other performance EVs in the same price range, and it is a night and day difference. Same with supercharging. But no, AP does not fall into that category.
 

Todd Burch

12-Year Member
Nov 3, 2009
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Smithfield, VA
Have you driven other cars, or is your opinion based on the article?

The article contains a decent experimental test. Not sure why it's not relevant, but I base it on that article, plus Road & Track and several other articles that say it's the best out there, plus youtube videos of other systems operating in the real world.

The auto lane change is somewhat of a gimmick, as it can't detect if there are cars behind you


Well you could argue most of the stuff in a luxury sedan is a gimmick. That's irrelevant to the argument.

No, it can't detect if there are cars well behind you and closing quickly on you. But it will see slightly behind, to the side, and slightly ahead. That doesn't invalidate its usefulness.

sometimes it doesn't want to change lanes when there are no cars.

In areas where autopilot is intended to be used, I find it to work almost 100% of the time. If it doesn't change lanes, I've found that almost always there is an understandable reason--e.g. the lane is a solid white line or the start of a turn lane, or there is a vehicle too close to where the nose would be to allow a safe following distance.

In addition, the auto lane change is very slow, if I need to change lanes normally (not if I'm driving out in the boonies, where there are very few cars), I'm often forced to disable AP, change lanes, and then re-enable AP.

I disagree here too...I think it changes lanes at the "recommended" speed. Obviously there are times where you will want to change lanes faster (e.g. you're coming up on traffic stopped in your lane), but for highway driving as intended the lane change speed seems right to me.

This is 100% a gimmick. When it can parallel park or perpendicular park with no one in the car, then I'll give them more weight.

Yes, a gimmick...but that does not invalidate the point. Parallel or perpendicular parking with no one in the car is just as gimmicky.

Your hands should be on the wheel at all times, even with the Tesla (sure, no one does it), so the nags should be irrelevant ;).

Given the number of threads with people annoyed by them, and the number of Mercedes and other drivers that attach weights to their steering wheels, I'd have to disagree that it's irrelevant there too. But I see your smiley wink :).

I have it cross through intersections too, but it often drifts out of lane, and then has to correct when it sees the lane markings again. I don't use that feature often.

Sure, it's not perfect...but if you're following another car, it's pretty reliable (assuming that car doesn't illegally change lanes in the middle of the intersection)...and as long as there's no significant curve or jog in the middle of the intersection, it tracks pretty well. I would say that on a typical daily commute, I cross through about 100 urban/suburban intersections on autopilot (probably 75% of the intersections on my daily drive where I'm not turning), and I only have to correct the system probably less than 10% of the time--and most of those are slight pulls one way or the other. OK, you don't use it much, but it's still something other systems can't do.

Tesla did a great job with the PR on AP. But there are many other companies who offer the technology at a slightly reduced maturity level.

Except that Car & Driver, Road & Track, and several other car magazines don't seem to think the differences are as small as you do. Sorry, I just put more weight in the opinion of people whose job it is to test and criticize cars...especially when no Tesla advertising goes to pay for those magazines.

Autopilot is obviously nowhere near autonomous driving. There are plenty of situations where you have to take over...I'm not arguing that. But clearly your idea of "slightly better" and my idea of "slightly better" are pretty different.
 

RAW84

Member
Oct 6, 2014
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327
Boston
I think autopilot is best on city streets. TACC will follow traffic all the way to a full stop. You just have to monitor what it is doing. I think TACC also remembers the last speed set which may explain the jump to 45 mph. I've had the same thing happen.

You think autopilot is best on city streets? Really???


It's adequate on many city streets but it's definitely best on highways. In addition to paying no mind to pedestrians, stop signs and stoplights, it also pays no mind to potholes, manhole covers, uneven sections of the road, speed bumps etc. Those issues are a lot less common on a highway designed for higher speeds.
 

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