Cars with emergency city braking

[Richie]

How much trust do you need to put in it to do this.

My dad had a C300 from Mercedes as a loaner and it had it, his work set up bubble wrap in a big wall and it crashed right through it lol

Thats because, on some of them, the camera system uses the numberplate of the car in front to detect distance and not the physical object itself. Do the same test but attach a numberplate to it.

Ford had an event at my local place a while back and they had an unflatable wall which at a numberplate attached. I drove a Kuga at it a few times (including with my eyes closed) and it worked brilliantly.

 

[Howard]

Got this on some of the trucks at work, experienced it once so far when a transit shot in front of me on the m25 as it made a late dash for his exit, scared the **** out of me when it activated but it worked, without it I'm sure I'd have hit him.

Holy christ that's impressive!!

 

[matthab]

Have it on the Leon. Its good and isn't intrusive, the warnings sometimes pop up when it isn't needed.

Worked very well when a child stepped out in the road behind a parked car. Didn't think it was possible to get whiplash from your own car.

 

[Semple]

Got this on some of the trucks at work, experienced it once so far when a transit shot in front of me on the m25 as it made a late dash for his exit, scared the **** out of me when it activated but it worked, without it I'm sure I'd have hit him.

Is that with an empty load though? I wonder if Volvo's system somehow calculates the extra stopping distance needed for the extra load you're carrying.

I can actually imagine a lot of lorry drivers not liking this system for the exact scenario that you posted. You'll have a lot of drivers cutting lorries up because they know that the lorry will auto brake.

 

[paradigm]

You'll have a lot of drivers cutting lorries up because they know that the lorry will auto brake.

Far worse will be when drivers start assuming that lorries have auto-braking and then try it in front of a truck that didn't have the system fitted

 

[joeyjojo]

Worked very well when a child stepped out in the road behind a parked car. Didn't think it was possible to get whiplash from your own car.

What would have happened if you didn't have it?

 

[paradigm]

He'd have braked, without being able to be as precise as the car (with regards to brake pressure, without activating ABS), and certainly with a slower reaction time.

 

[Scania]

Is that with an empty load though? I wonder if Volvo's system somehow calculates the extra stopping distance needed for the extra load you're carrying.

I can actually imagine a lot of lorry drivers not liking this system for the exact scenario that you posted. You'll have a lot of drivers cutting lorries up because they know that the lorry will auto brake.

I had 28 tons of Pepsi on my trailer, the whole load needed restacking after it shot forward mind you!

 

[Ryan-3]

Kudo's to the guy in the estate car testing it on that FH.

 

[Montala]

I didn't even realise that sort of thing was generally available, but it appears to be fitted to the new Mazda CX-3 I am thinking of buying shortly!

Very interesting!

 

[SDK^]

I can vouch the system in my Golf works fine after it initiated an emergency stop from 45mph, because the system identified a large plastic bag blowing in front of my car. It scared the *beep* out of me

 

[Minstadave]

Are these systems that smart? I'd have thought they just jam the brakes on 100% and just stop as quick as possible once a possible collision is detected.

 

[matthab]

What would have happened if you didn't have it?

I was all ready on the brakes and would have stopped but it was nice to have something to aid in case.

 

[Tom_ed1987]

I had an A-class hire car with this system and it nearly made me poo myself. Pulling in behind a lorry in L1 (not at all in an aggressive way) just before taking an exit on the motorway and despite my speed being nicely matched the car clearly judged I was about to run into the back of it & slammed on. Could have easily caused a massive accident if someone was racing up behind me to make a gap.

 

[Hotwired]

I had an A-class hire car with this system and it nearly made me poo myself. Pulling in behind a lorry in L1 (not at all in an aggressive way) just before taking an exit on the motorway and despite my speed being nicely matched the car clearly judged I was about to run into the back of it & slammed on. Could have easily caused a massive accident if someone was racing up behind me to make a gap.

I can vouch the system in my Golf works fine after it initiated an emergency stop from 45mph, because the system identified a large plastic bag blowing in front of my car. It scared the *beep* out of me

Doesn't make the system sound sketchy at all.

 

[Finglonga]

My GTI only ever braked hard once when a cyclist shot out of an alley onto the road in front of me. I trust it to stop should something major happen but because the brakes are so good I will probably get rear ended. Uses the same radar as the cruise control and drops the insurance group considerably.

 

[Frozennova]

Are these systems that smart? I'd have thought they just jam the brakes on 100% and just stop as quick as possible once a possible collision is detected.

They'll use wheel speed sensors etc to apply as much force as possible until a certain percentage of slip angle is detected then trigger the ABS at a guess

 

[acemastr]

Here's a debate:

Is the ABS engaged the most amount of braking possible, or just prior to this engagement?

 

[chaparral]

I can vouch the system in my Golf works fine after it initiated an emergency stop from 45mph, because the system identified a large plastic bag blowing in front of my car. It scared the *beep* out of me

What speeds does the golf one work up to ?
This says Volkswagen one only works at speeds up to 18mph http://www.volkswagen.co.uk/technology/braking-and-stability-systems/city-emergency-braking

City Emergency Braking

Automatically activated at speeds under 18mph, it uses a laser sensor to detect the risk of an impending collision and automatically primes the brakes to make them more sensitive.

This found this about the ford one
http://www.euroncap.com/en/ratings-rewards/euro-ncap-advanced-rewards/2011-ford-active-city-stop/

Ford Active City Stop is a system which helps to avoid or to mitigate accidents at low speeds. At speeds up to 30km/h, a lidar (Light Detection And Ranging) sensor positioned at the top of the windscreen scans the area up to around 7.6m ahead of the vehicle for possible obstacles. If the vehicle detects a braking, slower-moving or stationary vehicle in front and it determines that a collision is likely, the brakes are pre-charged. If the driver remains inactive (no steering or braking input), the car applies the brakes automatically and reduces engine torque.
At relative speed differences less than 15 km/h then Active CityStop may help the driver to entirely avoid the collision with the obstacle in front. If the relative speed difference between the two vehicles is between 15 and 30 km/h the impact is unavoidable through braking alone but Active City Stop will aim to reduce speed prior to the impact.
If the driver intervenes to try to avoid the accident, either by accelerating hard or by steering , Active City Stop will deactivate. Active City Stop is unusual for an autonomous emergency braking system in that it does not give the driver a warning of the impending collision, and brakes very hard, very late. This is intentional: the way in which the system intervenes is not comfortable and drivers will not become reliant on it to avoid around-town accidents.

 

[Frozennova]

Here's a debate:

Is the ABS engaged the most amount of braking possible, or just prior to this engagement?

In terms of stopping distance or pressure applied?

In terms of stopping distance I would imagine it's just before ABS engagement