Adaptive Cruise Fails to Brake to a Stop - Nearly Hits Car!

[CraigI]

Apple I consider damaging to the industry I work in, and their practices and ideologies are bad for everyone, and AFFECT everyone by reducing consumer choice, so I consider them to affect me, my industry and i'll continue to criticise them for it!

In any case, I don't tend to comment on Apple stuff unless asked my opinion on it, or the topic is directly about it (eg, the in-car integration with mobile OS thread the other day). Or someone else is talking nonsense about it!

So yes, double standards then.

By the way, I love Apple products, have 8 or perhaps 9 (may have a shuffle hidden away somewhere) within the household. Having tried numerous alternatives (Samsung, HTC, Nokia, Blackberry) ended up with an iPhone on my latest upgrade and won't go back.
Apologies if that has caused you undue distress.

Back on topic, OP get it back to Audi and get it checked out.
At the end of the day, whether I like the option or not, you have paid for it, so if you think something isn't working as it should, get it checked.

 

[Diamond White]

Am I right in assuming, that the adaptive part can be turned off and it can be used as standard CC.

 

[cemerson]

No, the adaptive part is permanent. Though why you'd want to turn it off I'm not sure!

 

[cemerson]

By the way, I love Apple products, have 8 or perhaps 9 (may have a shuffle hidden away somewhere) within the household. Having tried numerous alternatives (Samsung, HTC, Nokia, Blackberry) ended up with an iPhone on my latest upgrade and won't go back.
Apologies if that has caused you undue distress.

Why would it cause me undue distress? It's your loss, not mine

 

[ddscot]

I think the technology is pretty cool from a safety point of view, remember watching an A4 demo on youtube with ACC and Presense and the idea is if you were "asleep" and didn't know you were steaming up somebody else's backside at 80MPH it could save both car occupants lives, pretty good idea in those exact circumstances and one of those things I think is a "last resort" not to be depended upon but nice idea.

Could you have been going round a bend at the time as that is an issue that some systems had earlier on, losing lock to the target in front?

 

[cemerson]

The ACC in the A3 seems remarkably good at tracking cars around corners and in lanes

 

[steeve]

I too use cruise and find it helpful. But I don't have to keep switching it on and off, as you know its possible to reduce the speed and then increase it, but I'm doing it by watching the road ahead and making that decision. I'm sure the vast majority of adaptive users will be as alert as those without it, but sadly there will be people who will rely on it and it doesn't work in all situations, the muppets out there will see it as an aid to allow them even greater opportunity to answer the phone, send texts, make phone calls and check emails.
As I'm sure no one on here is irresponsible enough to do any of those things whilst driving.

We've all heard the stories of motor home users in the US setting cruise and then nipping in the back to make a cuppa........

 

[AU11 ALS]

I've experienced two different functions of this system, one in a Golf GTD where the ACC brought the car to a complete stop and also accelerated away when the stationary car in front moved, the second was in a Q5 where the car did not brake to a stop and i had to step in.

I tested the Q5 with all settings and the performance of the system was the same in all. Not sure if it was working as it should but it certainly didn't impress me like the Golf version did

What I have found though is the ACC makes motorway driving much more relaxed and better paced, making my ing journeys less tiring and arriving more alert

 

[Leeber]

No, the adaptive part is permanent. Though why you'd want to turn it off I'm not sure!

Really? I'm very surprised to read this! I tried a Golf with ACC before test driving the S3 and the Golf system had both an adaptive and non-adaptive mode. Didn't think to check if that was the case on the Audi as I just assumed it would be the same.

 

[cemerson]

Are you sure the golf had that? Unless there's a setting in the MMI which I've missed, that's the case.

Although again, why would you want to turn it off? It functions the same as a cruise control with the added bonus that it won't crash into the car in front if you are going a bit faster. Why would you want to enable it to crash? Seems strange!

 

[Leeber]

Are you sure the golf had that? Unless there's a setting in the MMI which I've missed, that's the case.

Although again, why would you want to turn it off? It functions the same as a cruise control with the added bonus that it won't crash into the car in front if you are going a bit faster. Why would you want to enable it to crash? Seems strange!

Absolutely positive. When I attempted to engage the cc it was initially in normal cruise mode. The rep explained how to activate the adaptive mode before re-engaging it, worked like a charm after that.

As you say though, it's hard to envisage a scenario where you would choose not to have the adaptive mode selected so perhaps it's not such a big deal.

 

[luadr1]

Are you sure the golf had that? Unless there's a setting in the MMI which I've missed, that's the case.

Although again, why would you want to turn it off? It functions the same as a cruise control with the added bonus that it won't crash into the car in front if you are going a bit faster. Why would you want to enable it to crash? Seems strange!

It would be useful in case of a radar sensor malfunction.

 

[cemerson]

If you think functionality should be arranged around the assumption that things will go wrong, perhaps

 

[Kingfisher]

all very interesting!
I was thinking that ACC was a likely BENEFIT and was thinking I may spec it - now not at all sure!
I enjoy driving, not piloting and I'm all for safety items.
No safety aids can excuse a driver from paying full attention to what they are doing, ever. It's the same with ABS
I'm used to CC, but I find I can really only use it in roadworks and restricted speeds on motorways - yes it's useful but most of the motorways I drive on are often too busy to use it safely ( M4 M25 M40 M3 M6) - and I can always get better economy than CC can!!

Oh I've been driving for 47 years and approx. 400k miles in a car and 300k on two wheels so I'm reasonably experienced !!

 

[Leeber]

If you think functionality should be arranged around the assumption that things will go wrong, perhaps

Indeed the Airbus that I drive for a living is arranged in exactly that way.

Perhaps I'll leave my spare wheel at home too!

 

[cemerson]

CC is hardly essential for the control of driving though, so not likely a system that will be designed with backup in mind.

Do they teach you how to fly Airbuses these days or just let the plane do it all for you?

 

[cemerson]

By the way, this a great talk about the future of this technology:

https://www.youtube.com/watch?v=p_KE51EtKhc

 

[arad85]

Anything which might endanger life if it goes wrong needs to be designed to fail safe. Period.

 

[cemerson]

'A car' then.

A cruise control, if it detects a problem, will just not you use it. Simple as that. It's impossible to get 100% fail safe, just reduce risk by building in redundancy, backups for mission critical applications, but it isn't worth it for secondary systems as the need for a backup isn't there.

 

[Leeber]

That my friend is a huge topic of debate within the profession ATM. We all rely on automation for the vast majority of the time that we're in the air for two main reasons. Firstly hand-flying the aircraft takes a lot of concentration, to do so for an entire flight is exhausting (depending on the length of the flight of course), we wouldn't be able to do 20 flights a week if we had to do all them without automatics. Secondly, by allowing the automatics to take care of the task of actually allowing the plane to fly itself it frees up our tiny brains so that we can maintain better situational awareness i.e what's going on in the skies around you. We do make every effort to keep our skills alive though by switching off the autopilot and polling the bird the old fashioned way when it's entirely appropriate.

Anyhow, Luadr's point is valid IMHO, you would expect some redundancy to be built into the system, I doubt it would cost anything. I see ACC as similar to an autopilot. It's not there to do your job for you, just to make it easier and allow you the capacity to have a better situational awareness. You still have to be ready to intervene when it's not playing nice.

 

[cemerson]

I'm aware of the debate, and all the Boeing vs Airbus 'methodologies'. I'm a pilot myself (though gliders..) and quite involved with Aviation generally.

I think the Air France accident in 2009 shows exactly what happens when people have too much faith in the systems and not enough situational awareness or awareness of limitations.

 

[Leeber]

I'm aware of the debate, and all the Boeing vs Airbus 'methodologies'. I'm a pilot myself (though gliders..) and quite involved with Aviation generally.

I think the Air France accident in 2009 shows exactly what happens when people have too much faith in the systems and not enough situational awareness or awareness of limitations.

That doesn't surprise me one bit. If the various usernames are anything to go by, there are quite a few of us lurking around this forum. I'm surprised no-one else has chimed in.

We had quite a lot of training as a result of the Air France tragedy, from what I understand of that incident it was a combination of the avionics feeding them duff/conflicting info along with very experienced pilots being so maxed out that they forgot what we all learn in our first 10 hours of flight training, the relationship between power, attitude and performance.

Anyhow, this is way off topic. The OP stated that a fault or failure of the ACC should be accompanied by an audible tone to let you know that you're back in control. I agree, that's exactly what happens when an aircraft AP is disengaged/fails. However I don't think that it's ok to hang yourself on someone's rear bumper just because you have ACC engaged, regardless of how "advanced" your driving skills are. You need to leave enough room for you to realise that the system has fallen over and then intervene without endangering either car (if indeed that's possible).

ACC is a fantastic feature which has the potential to enhance safety as long as it's limitations are fully understood and it's used correctly.

I would also be interested to know the outcome of any investigation if the dealer doesn't just try and fob it off.

 

[cemerson]

Might be worth asking what the ACC radar looks like seeing as we recently discovered there were 2 different types - is it the round type, or the flat one?

 

[drtav13]

I've been using acc ( acc high , the one with the bulb ) daily for the past 8 months and I really think that it is an impressive and very accurate system. Depending on how quickly it has to respond you might not get all available warnings.
Normally the first action is a warning beep followed by a momentarily press of the brakes , the final action is to completely stop the car.

A couple of months ago I've entered a blind turn and I was running around 120 km .
Unfortunately an accident has occurred exactly at the turn and the drivers involved haven't managed to place a warning triangle at the entry of the turn.
To my surprise the car came to complete stop just as was realizing what has happening and prior to my reaction.
I believe that I could have stopped the car by myself , but I wouldn't bet my money on it.
I didn't get an early warning brake or warning sound , the car just pressed hard on the brakes and at the same time the screen turned to a red warning triangle and also beeped.

I'm also using it on heavy traffic when I'm really bored , in conjunction with s-tronic is fantastic.

I've read an article on how this system works and it mentioned that it's designed to react as late as possible so that you don't drop your attention while driving. If you really want to test the possibilities of the system you have to play chicken with the cars in front of you ( just don't blame me if something goes wrong )

The only problem I've noticed so far is that the system has a difficulty to detect the car in front of you in case there is a height difference ( e.g. Bumpy roads).
The delay to detect the car under those conditions could be critical to stop the car in time and might cause an accident . Personally I'm not brave enough to test this scenario but on any other occasion I'm certain that the car will stop.

 

[cemerson]

The only problem I've noticed so far is that the system has a difficulty to detect the car in front of you in case there is a height difference ( e.g. Bumpy roads).
The delay to detect the car under those conditions could be critical to stop the car in time and might cause an accident . Personally I'm not brave enough to test this scenario but on any other occasion I'm certain that the car will stop.

But that's fine - I have noticed this too, and now we are both aware of a limitation of the system. The more you use the system and explore it, the more you know about its limitations, and you (and I, and anyone else reading this) now know to be alert over this kind of terrain, and what to look out for. The same thing happens in other situations.

I've never tried distance 1 (I think that's a bit too close personally), but am normally on distance 2, or 3 if very wet, probably would use 4 if there was snow / ice around.

 

[constvoid]

Regarding the ability to fail back to 'normal' cruse control mode - when I was researching whether to order the ACC (not that there was ever really much doubt) I did come across some info on other VAG ACCs (may have been Audi or possibly VW) which implied this was possible by holding the CC lever in the 'off' position (ie against the spring loading) for a number of seconds. I've never actually tried this on the A3 as, like others have suggested so far, why would you want to if it's working properly in ACC mode.

There's no mention of this in the manual, and if it's not implemented on the A3 i can only assume it's a safety feature in it's own right - if you were used to running in ACC mode and it had actually been switched back to normal CC mode (e.g. by another driver) then you might end up risking a collision if you were relying on ACC slowing down. Mind you, pre-sense, if it's enabled, should still alert you, as that is independent of ACC.

 

[lee_fr200]

These distance settings what do they actually represent and how many distance options are there

So distance 1 = ?
Distance 2 =

Etc etc

 

[misthills]

These distance settings what do they actually represent and how many distance options are there

So distance 1 = ?
Distance 2 =

Etc etc

They actually represent times rather than distances (if you are going slowly the distance is much smaller than when going quickly).

Distance 1 = ~1 second = 28 meters @ 60mph
Distance 2 = ~1.3 second = 36 meters @ 60mph
Distance 3 = ~1.8 second = 50 meters @ 60mph (default)
Distance 4 = ~2.4 second = 67 meters @ 60mph​

 

[cemerson]

Yes, one of the things I like about it is that it spaces things out a lot more on the motorway, makes a lot of sense being based on times obviously

 

[lee_fr200]

Well in all honesty I'd set it at maximum distance then because on a busy motorway you don't need the hassle of been up someone's ****

 

[misthills]

Well in all honesty I'd set it at maximum distance then because on a busy motorway you don't need the hassle of been up someone's ****

For long distance driving that works well but distance 4 tends to leave large gaps that other cars keep sliding into. The adaptive takes over and pushes you back even further allowing another car in. You will probably find yourself adjusting the setting based on the situation (it's easy as it is just a toggle on the cruise control stalk).

 

[royalsteve68]

Maybe it makes sure you're not taking a nap in there...what is world coming to ? Cars that park themselves, adaptive cruise control, auto lights, auto wipers,etc...soon one won't need a driving licence in order to drive a motor vehicle !

eh, but ive selected parking aid and parking assist, auto lights, auto wipers and acc. you mean this doesn't mean I cant have a sleep at the wheel....darn!

joking aside though is I only view these systems purely as aids as audi have rightly called them. However acc is the one aid im a little wary of eg do I trust it

 

[cemerson]

Isn't one day being able to use a car without needing a licence a good thing?

Steve: You'll get used to ACC soon enough. It has very few quirks, works remarkably well, and you'll soon learn the limitations and best uses of it.

 

[luadr1]

Isn't one day being able to use a car without needing a licence a good thing?

Steve: You'll get used to ACC soon enough. It has very few quirks, works remarkably well, and you'll soon learn the limitations and best uses of it.

What are, in your opinion, its limitations?

 

[cemerson]

If you scroll a few posts up, you'll see that steepish hills are one of them. Slow speeds for the manual (and making sure you are in the right gear), changing lane while doing 80mph directly behind someone doing 20mph won't be too pretty I imagine, it won't see stationary things (though pre-sense front will, not to be relied on though), it sometimes (at slow speeds) slows down when things pull into a right hand filter lane and slow right down in front of you (left isn't so much an issue, but it will still slow down not realising that they'll be out the way very soon). It usually won't undertake a vehicle in the lane to the right unless it has seen a car in front of you also undertake, which is a good thing as it doesn't know if that car may be partly in your lane. You can override this just by briefly pulling the CC stalk back to 'confirm' the undertake (if you've given them a chance to move over and they still don't understand how lanes work...), etc. You just get a feel for what the system can do. You learn most about a system or vehicle by exploring the edge cases and the boundaries.

If I fly a new type of glider for the first time for example, I'll get a much better idea of the handling and behaviour of it if I stall it, do some steep turns, really push it to the boundaries (safely at height), than if I just fly well within the limits at all times, and it can be useful to know what to expect in certain cases (eg, if you get into that situation low to the ground).

 

[cemerson]

I did come across some info on other VAG ACCs (may have been Audi or possibly VW) which implied this was possible by holding the CC lever in the 'off' position (ie against the spring loading) for a number of seconds. I've never actually tried this on the A3 as, like others have suggested so far, why would you want to if it's working properly in ACC mode.

I did try this yesterday on the way home, while the ACC was both active, and also when it was on but inactive, it didn't do anything either time - the adaptive part stayed on.

 

[Silky-S3]

If you scroll a few posts up, you'll see that steepish hills are one of them. Slow speeds for the manual (and making sure you are in the right gear), changing lane while doing 80mph directly behind someone doing 20mph won't be too pretty I imagine, it won't see stationary things (though pre-sense front will, not to be relied on though), it sometimes (at slow speeds) slows down when things pull into a right hand filter lane and slow right down in front of you (left isn't so much an issue, but it will still slow down not realising that they'll be out the way very soon). It usually won't undertake a vehicle in the lane to the right unless it has seen a car in front of you also undertake, which is a good thing as it doesn't know if that car may be partly in your lane. You can override this just by briefly pulling the CC stalk back to 'confirm' the undertake (if you've given them a chance to move over and they still don't understand how lanes work...), etc. You just get a feel for what the system can do. You learn most about a system or vehicle by exploring the edge cases and the boundaries.

If I fly a new type of glider for the first time for example, I'll get a much better idea of the handling and behaviour of it if I stall it, do some steep turns, really push it to the boundaries (safely at height), than if I just fly well within the limits at all times, and it can be useful to know what to expect in certain cases (eg, if you get into that situation low to the ground).

Didn't know about the undertake thing. Cheers

 

[constvoid]

In addition to this, if you're in a queue of traffic, where where traffic on the left is moving more quickly that that on the right, contrary to the normal UK situation, the ACC eventually 'learns' that you've moved to a country which drives on the right, such that when you leave the queue, and traffic returns to to the normal left-to-right speed pattern, it can be reluctant to overtake a car on the left. Again pulling the stalk. or just accelerating past it manually eventually sorts it out. You may need to do this 2 or 3 times before it's back to normal.

 

[cemerson]

I've not noticed that one!

 

[constvoid]

It might only happen if you get this reverse queueing situation near the beginning of your journey. I live within a few minutes drive of a busy section of 3-4 lane motorway and have seen this happen a few times. When I first had the car, and someone posted here that the ACC was reluctant to 'undertake' I posted in reply saying I hadn't seen that and how would it know you weren't driving on the right. I guess I know now.