Active Cruise Control Not Reducing Speed to 20 Mph

Active Cruise Control Not Reducing Speed to 20 Mph

Author
Discussion

MJC44

Original Poster:

8 posts

6 months

Saturday 23rd November 2024
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I have an issue with Active Cruise Control, on my X1 using OS9, which is set to automatically adjust my speed to the UK speed limits. It normally works fine changing my speed up or down as I enter a new speed zone. However I find that with it set so that it automatically speeds up to the new higher speed limit my speed can increase faster than I want it to so in the settings I have set it so that below 40 Mph the speed will be set to 7 Mph below any speed limit and above 40 mph it is set to 10 Mph below the limit and I find this ok and I can then manually insures the cruise control speed as I think fit.

The issue is that, without the 7 Mph lower limit set, when I enter a 20 Mph Zone the cameras detect the 20 Mph zone the car reduces speed to 20 Mph exactly as I want.

However when I have the 7 Mph below the speed limit set in the system then when entering 20 Mph areas, the Speed limit in the Heads Up Display is shown as going from 30 to 20 but the cruise control speed does not reduce. For example if I am traveling in a 30 Mph Zone with Cruise Control set at say 25 Mph when I enter the 20 Mph zone the 20 Mph speed limit is shown in the Heads Up Display but the Cruise Control stays at 25 Mph rather than reducing to 20 Mph. I am assuming that this is a software issue where, as the minimum speed that Cruise Control can be set at is 20 Mph and I have set an offset of minus 7 Mph, that the system can’t implement this instruction so doesn’t reduce the Cruise Control speed. I would have expected that it would reduce the speed to the lowest that it could ie 20 Mph.

Any body else having this issue?

Krikkit

27,288 posts

193 months

Saturday 23rd November 2024
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Everybody on the same version I'd imagine. I agree with your assessment that they've used the gating logic wrong with the limit adjuster being below minimum. Instead of just hitting minimum it's probably logging an error internally and aborting the speed change.

Mr Tidy

25,974 posts

139 months

Saturday 23rd November 2024
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Can't you just read the speed limit signs and control your right foot?

Works for me!

donkmeister

9,919 posts

112 months

Sunday 24th November 2024
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Or set the cruise offset to zero instead of pissing about going 7mph under. Are you an Uber driver by any chance?

E-bmw

10,655 posts

164 months

Sunday 24th November 2024
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Don't know if this is true for yours but some CC's won't go below a setting of 20 mph.

MJC44

Original Poster:

8 posts

6 months

Sunday 24th November 2024
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Of course I can and I have set it back to zero. It’s just the fact it doesn’t work as it should do that bugs me after paying for the system.

MikeM6

5,423 posts

114 months

Sunday 24th November 2024
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Is the problem that you have set the cruise control too low? If you have it set to be 7mph below the limit (not sure I understand why you would do this to be honest), then does that mean you would be trying to drive at 13mph in a 20 zone? Surely that is far too slow for the system to operate at.

Why not just leave it at the speed limit? If it's adaptive cruise, then I would imagine it would simply match the speed of the car in front anyway, so having it set to limit you at the limit posted is surely the correct thing to do.

Is it normal to delegate throttle control in a 20 zone? It would seem to me that, given the inherent hazards that you should detect before the car can, a driver ought to be fully in control of a vehicle in such an urban environment.

MJC44

Original Poster:

8 posts

6 months

Sunday 24th November 2024
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Hi Yes number one the driver has to be in control of the vehicle and monitoring what is happening.
However the Assisted Driving function allows you to let the system keep you at, above or below the speed limit, which should avoid speeding tickets when set at or below the limit.

The issue, that I have with it being set to the speed limit, is that when going from a 30 Mph Zone to a 70 Zone is that the car suddenly accelerates at a lot faster rate and to a higher speed than I would normally drive at. So the ability to set a level less than the speed limit means that I don't increase my speed too much.

You are correct that 13 Mph would be too low, but as the lowest speed that Cruise Control works at is 20 Mph I was hoping that it would default to that even with the 7 Mph Offset. But its not doing that so I will have to either have no offset and put it on standby when going to a higher speed zone. which I have been doing in order that it will function, when turned on, to slow me down when entering a 20 Mph area.

I main intention is to ensure that I am slowed down to 20 Mph when entering the 20 Mph zone and after that I usually dip the brake to turn cruise control off and then control the speed by throttle.

The area where I live has 20 Mph zones are springing up every day.


Super Sonic

8,771 posts

66 months

Sunday 24th November 2024
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Why not just brake when entering a 20mph zone?

E-bmw

10,655 posts

164 months

Sunday 24th November 2024
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Super Sonic said:
Why not just brake when entering a 20mph zone?
Clearly it seems the OP is far too busy to be involved in the driving process. wink

Caddyshack

12,276 posts

218 months

Sunday 24th November 2024
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The car accelerates more than the driver wants or to a higher speed…most cruise controls are very gentle at building speed. I didn’t think it was possible to accelerate too fast or to go too fast within a speed limit (in terms of comfort or want)

I often wonder what other drivers are up to when driving behind them, this may explain some of it.


I was following a lady in a local care team liveried car recently she was doing 13mph in a 30 and she was braking for corners.

CanAm

10,731 posts

284 months

Sunday 24th November 2024
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MJC44 said:
Hi Yes number one the driver has to be in control of the vehicle and monitoring what is happening.
However the Assisted Driving function allows you to let the system keep you at, above or below the speed limit, which should avoid speeding tickets when set at or below the limit.

The issue, that I have with it being set to the speed limit, is that when going from a 30 Mph Zone to a 70 Zone is that the car suddenly accelerates at a lot faster rate and to a higher speed than I would normally drive at. So the ability to set a level less than the speed limit means that I don't increase my speed too much.

You are correct that 13 Mph would be too low, but as the lowest speed that Cruise Control works at is 20 Mph I was hoping that it would default to that even with the 7 Mph Offset. But its not doing that so I will have to either have no offset and put it on standby when going to a higher speed zone. which I have been doing in order that it will function, when turned on, to slow me down when entering a 20 Mph area.

I main intention is to ensure that I am slowed down to 20 Mph when entering the 20 Mph zone and after that I usually dip the brake to turn cruise control off and then control the speed by throttle.

The area where I live has 20 Mph zones are springing up every day.
Why not just use the ISA (which by default is on at startup on all new cars) and limit your use of cruise control to actual cruising? You could then pootle along at your chosen 13 or 23 mph in built up areas with impunity, and not have to worry about Sudden Unintended Acceleration when moving into a higher spped limit area.


Edited by CanAm on Sunday 24th November 16:57

Wills2

25,448 posts

187 months

Sunday 24th November 2024
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The system has probably cottoned on to the fact that no one does 20mph in a 20 zone, unless you live in Khan's London.


drdino

1,182 posts

154 months

Monday 25th November 2024
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I guess there's no perfect way of implementing it, you are asking it to have the setpoint at 13mph which is below the minimum engagement speed. They could either trigger a disengagement (that would cause customer dissatisfaction) with the "Automatic adoption of speed limits not available" message displayed, go to the minimum it could do as per its limits (but then there would be a mismatch between your expectation and what it has done) or do nothing (again, causing dissatisfaction, possibly even a ticket if you weren't paying attention).

I'll see what my G20 with DAP does (albeit with ID7).

MJC44

Original Poster:

8 posts

6 months

Wednesday 27th November 2024
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Yes you are correct there is no perfect solution. But to be clear I am only wanting the speed when entering 20 Mph zones to reduce to 20, which I know is the minimum that the Cruise Control will operate at. I appreciate that with the 7 Mph offset the system thinks that I am asking it to reduce to 13 Mph.
However this results in the situation where if the car were set to cruise at 30 Mph without the offset the speed automatically reduces to 20 when entering a 20 zone, but with the offset the system ignores the 20 Zone and continues at 30, I would prefer, for safety reasons that it would at least reduce the speed to the minimum it could, ie 20, rather than continue at 30 Mph.
I have to say that I have now deactivated the Active Speed Control, as overall I don't find it as useful as I was initially thinking it would be.


Caddyshack

12,276 posts

218 months

Wednesday 27th November 2024
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MJC44 said:
Yes you are correct there is no perfect solution. But to be clear I am only wanting the speed when entering 20 Mph zones to reduce to 20, which I know is the minimum that the Cruise Control will operate at. I appreciate that with the 7 Mph offset the system thinks that I am asking it to reduce to 13 Mph.
However this results in the situation where if the car were set to cruise at 30 Mph without the offset the speed automatically reduces to 20 when entering a 20 zone, but with the offset the system ignores the 20 Zone and continues at 30, I would prefer, for safety reasons that it would at least reduce the speed to the minimum it could, ie 20, rather than continue at 30 Mph.
I have to say that I have now deactivated the Active Speed Control, as overall I don't find it as useful as I was initially thinking it would be.
They are really frustrating systems, active cruise can be a pain as well as a godsend