Adaptive Cruise Control - Golf 7.5

[ABCD]

New owner of GTi 6 sp manual with DAP.
The ACC works well on the open road and seamlessly winds back speed if it encounters slower moving vehicles. However unlike a similar system I have used in a Mercedes it does not recognise stationary vehicles. For example travelling along with it set to say 80 and then you come across a car in the distance waiting at a red light. There is no apparent attempt to slow and I have not been game to test it - even at the point I eventually lose my nerve and hit the brakes it requires a pretty abrupt stop to pull up.
I am wondering whether this might be something to to with my car having a manual transmission but I am keen to hear whether others with ACC in auto equipped cars have this same experience and thus if it is a "feature" of the VW ACC system, or of course that there is a somewhat worrying glitch with mine!!
And a related question to this I under the impression that the Golf Performance models had Emergency Braking or something similar ie in the scenario above approaching a stationary object the car should (eventually) automatically hit the brakes if the driver fails to do do?

[Jap]

Says in the Manual it won’t recognise stationary cars

[gregozedobe]

I think the slow speed emergency braking is quite different to the ACC braking. I know my R has jammed on the brakes a couple of times when it thought I was in danger of hitting something (the dip going from my driveway to the road worries it, so I just lightly rest my foot on the brake pedal to reassure it I have the situation under control and it seems happy). It is very sudden and sharp and juddery when it activates.

My ACC sometimes has conniptions when a car is turning in front of me even though I can see it will be well out of the way by the time I get there. The ACC has applied the brakes on me a couple of times, so now I just press on the accelerator if I feel it hesitating.

[ABCD]

Yep discovered the slow speed emergency braking already. Doing what must have been first reverse park - into a typically tight parking space where I live - and it slammed on the brakes on me. Very violent and over the top application - I thought initially I had hit the car behind.
Have been too busy driving the car to read the 400 odd pages of size 8 font that is the Owners Manual but I have just read the ACC section to discover it indeed does not recognise stationary vehicles. Even then it is still not clear whether this is referring to stationary vehicles parked in the kerbside lane for example. I would have thought it could at least make an effort to recognise and respond to stationary vehicles in the lane I am travelling in but clearly mine is not able to do so which for me significantly limits its usefulness to all but open road driving.

[crainger]

I have 2018 MK7.5 GTI Auto. It will slow and stop behind stationary vehicles. It's a little hair raising in sport, but in comfort mode for ACC is pretty normal, still a little late for my taste.

Once pulled up it will move off with the traffic on it's own, or if start/stop kicked in I just tap the accelerator and it's off on it's own again. In comfort it's slow to catchup with traffic. In sport it's up to speed again.

It's nothing like the emergency brake. That is something else, It's hard, way harder than I'd ever felt before, even at 40km. I had this happen when a teenager ran in front of my car in a laneway.

So maybe it doesn't work like the above in a manual, but it took me a while to work up the nerve to let the system brake on it's own. Even now I prefer to turn it off and coast to a traffic light.

[Kachingg]

I have 2018 MK7.5 GTI Auto. It will slow and stop behind stationary vehicles. It's a little hair raising in sport, but in comfort mode for ACC is pretty normal, still a little late for my taste.

Once pulled up it will move off with the traffic on it's own, or if start/stop kicked in I just tap the accelerator and it's off on it's own again. In comfort it's slow to catchup with traffic. In sport it's up to speed again.

It's nothing like the emergency brake. That is something else, It's hard, way harder than I'd ever felt before, even at 40km. I had this happen when a teenager ran in front of my car in a laneway.

So maybe it doesn't work like the above in a manual, but it took me a while to work up the nerve to let the system brake on it's own. Even now I prefer to turn it off and coast to a traffic light.

It is the best on a drive home when your knackered and could not be bothered just engage acc and be wafted home

Love it

[dArK5HaD0w]

On the MY17 Superb with ACC and DSG, it will not gracefully pull up (from any speed) behind an already stationary vehicle. It will scream "Brake!!" in red and jam on the brakes.

the user manual states the same thing too.
i found this the "**** in my pants" way.


it has no issues coming to a stop if the car in front (being followed) comes to a stop.
this is done gracefully
and resumes gracefully.

[LibraR]

It seems that if the vehicle in front was moving and then stops (such as occurs in heavy traffic) it pulls up just fine (and restarts if the stop was less than a couple of seconds). Not so if you are blissfully ACC-ing your way down the freeway and happen across a jam of stationary cars in front.

It may we’ll scream to a halt at the imminent crash avoiding second, but like others here, have not felt the scientific urge to test it lest there is the massive rear ender at 100km per hour... 😳

A bit of a butt-puckerer the first time. I’m on to it now.

I realise this is different to the slow speed impact avoidance which can be a shock but as the speed is very low, is far less disconcerting than the lack of velocity reduction when bearing down on the line of traffic sitting on the motorway ahead of you...

[kamold]

It's all about the delta.
If you're travelling at 80kmh and the traffic in front around a bend is all of a sudden stopped, the radar software has to interpret that as either oncoming traffic, or parked cars.
This isn't a level 5 autonomous vehicle. It's a 'driver assistance' system.

If you are travelling in a straight line at 80kmh and the car in front is already radar locked and suddenly stops, your car will also stop.
The systems are designed to work on divided motorways where there are understood parameters (ie curves will not exceed 15 degrees radius, traffic is travelling unimpeded because of on/offramps, no traffic lights etc.)
Understanding the design limitations and working within them leads to a greater appreciation of what the systems do well.
TJA works well because it has a vehicle in front to track. Not just relying on road markings.

So experiment safely what the limits of the assist systems are (ie closely supervise with hands hovering around the wheel, foot hovering on the brake) and then once you understand them you will be able to supervise the systems to make your drives less stressful.

[ABCD]

Hi all OP here and thanks for the replies. My reference for my original query is a 2015 E class Mercedes that I happened across for a few days earlier this year and got to fiddle with a lot of its gadgetry including MB's version of ACC. My initial recollection was that the Merc could when ACC active recognise stationary vehicles. However reading a few of your responses I am now beginning to wonder whether my recall might be inaccurate ie that the Mercedes was being slowed and comfortably brought to a complete stop by the car that it was "locked" in to, as opposed to the scenario I originally posed ie belting along in an empty lane with ACC active and being able to recognise and respond to an already stationary car in the distance.

[X-Rated]

Adaptive Cruise Control - Golf 7.5

Hi all OP here and thanks for the replies. My reference for my original query is a 2015 E class Mercedes that I happened across for a few days earlier this year and got to fiddle with a lot of its gadgetry including MB's version of ACC. My initial recollection was that the Merc could when ACC active recognise stationary vehicles. However reading a few of your responses I am now beginning to wonder whether my recall might be inaccurate ie that the Mercedes was being slowed and comfortably brought to a complete stop by the car that it was "locked" in to, as opposed to the scenario I originally posed ie belting along in an empty lane with ACC active and being able to recognise and respond to an already stationary car in the distance.

Exactly. I’ve just sold a 2014 Mercedes A-Class, and moved into a 2017 Mk 7.5 Golf. The M-B active cruise control performed similarly to the Golf ACC. If you’re locked on to a preceding vehicle, it’ll bring you to a stop behind him. But if he’s already stopped, beyond radar range, it won’t.

This makes sense - as you wouldn’t expect it to brake you to a stop approaching an empty T-junction with, say, trees on the far side. The radar can only identify its target as a car if there is a speed differential of < your speed between you and him. If he’s doing 10kmh and you’re approaching from directly behind at 80kmh, difference (80-10) = 70, therefore target must be moving, ie: a car. If he’s stopped, and you’re approaching at 80kmh, difference (80-0) = 80, therefore target could be a road sign or a brick wall or a tree, so, as the system can’t positively identify the target as a car, it doesn’t slow you down. You wouldn’t want it to, otherwise as soon as the radar beam happened to pass through ANY stationary object it’d be jumping on the brakes.

Disclaimer: I’ve used various aircraft radars for the last 30+ years, and my thinking is based on the fact that the underlying physics involved in the design of MB/VW car’s cruise control radar must be the same.

A.

[dArK5HaD0w]

from the user manual......

- Emergency Braking at Low Speed
if risk of collision between 5 to 45 km/h - the system triggers automatic braking.

- Advance Warning
advance/pre warning is triggered when risk of collision with a moving object when travelling between 30 to 210 km/h. no braking is applied.
advance/pre warning is triggered when risk of collision with a stationary object when travelling between 30 to 85 km/h. no braking is applied.

- Automatic Braking
if the driver does not react to the advance warning with a moving object, the system begins to automatically brake.
if the driver does not react to the advance warning with a stationay object, the system begins to automatically brake in a speed range of 30 to 60km/h.

- Brake Assist
if the driver brakes inadequately with an impending collision, the system automatically increases the braking force.

[Mitch204]

With ACC and cruise control set at 100kmh my Golf R Grid will apply brake if there is a corner I can comfortably take at say 60kmh...normal?

[Guest001]

With ACC and cruise control set at 100kmh my Golf R Grid will apply brake if there is a corner I can comfortably take at say 60kmh...normal?

Good luck with that

[Mitch204]

Good luck with that

Meaning????