Pre collision alert system

[ChaoticFury09]

Wow, I had no idea. Thank's for the info! That explains a lot since it was not sounding off on my last track day. I just assumed the low setting was really low.

No problem. I’m glad I could help. I’m 99% sure and I’ve read it somewhere but I’ll have to search around for it.

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[Michael_vroomvroom]

Just to add another data point to this, or perhaps a rant as it turned out: this morning I almost hit someone. Two lane road through the city centre in the "morning rush". Left lane completely still (waiting for traffic light to turn green, as there is a stretch of road that is one lane only). In between the long line of cars not moving there is a pedestrian crossing and I'm following the flow in my lane at around 20 mph. Suddenly a dude walks out from between two cars into my lane (yes, on the pedestrian crossing). I slam the brakes, can feel the car slide forward on the tires a bit, and the engine stalls. Very, very, barely miss the idiot. No warning from the pre-collision system.

I've been wondering a bit if it only activates once you reach a certain speed, but from what I read, that speed is quite low (6 mph), so that should not have been the reason it did not activate today.
Another thing I read is that it's uses pedestrian "shapes" stored in memory, presumably comparing the shape in memory to the shape ahead. Since by the time I hit the brakes, only half the guy was visible (one leg, one arm), possibly not enough of his shape was yet visible to match the shape stored in memory and that is the reason it did not activate.

Almost makes me miss living in south-east Asia, where pedestrians will stand and wait at the zebra line, just hoping some car will be kind enough to stop, and then quickly and carefully hurry across, giving a thankful smile. Even though I don't like that so much (I like walking too), it's better than here, where they suddenly walk almost blindly into the zebra line, not giving an ounce of thought to whether the cars coming will see you and have enough time to stop or not. Then give you the stink eye because you have to slam the brakes.
Even worse in the Nordic countries, where you will frequently experience idiots, often with headsets on too, walking forward on the sidewalk, then without any warning at all suddenly step out into the pedestrian crossing without even casting a glance backwards. "I have the right of way here. Don't you dare hit me for any reason whatsoever." Yeah, I'll be at fault (unless dash cam showing the idiot will serve as mitigating circumstances), but you'll be dead or in the hospital at best. You had the right of way though. Hooray for you.

 

[Bikeman315]

Just to add another data point to this, or perhaps a rant as it turned out: this morning I almost hit someone. Two lane road through the city centre in the "morning rush". Left lane completely still (waiting for traffic light to turn green, as there is a stretch of road that is one lane only). In between the long line of cars not moving there is a pedestrian crossing and I'm following the flow in my lane at around 20 mph. Suddenly a dude walks out from between two cars into my lane (yes, on the pedestrian crossing). I slam the brakes, can feel the car slide forward on the tires a bit, and the engine stalls. Very, very, barely miss the idiot. No warning from the pre-collision system.

I've been wondering a bit if it only activates once you reach a certain speed, but from what I read, that speed is quite low (6 mph), so that should not have been the reason it did not activate today.
Another thing I read is that it's uses pedestrian "shapes" stored in memory, presumably comparing the shape in memory to the shape ahead. Since by the time I hit the brakes, only half the guy was visible (one leg, one arm), possibly not enough of his shape was yet visible to match the shape stored in memory and that is the reason it did not activate.

Almost makes me miss living in south-east Asia, where pedestrians will stand and wait at the zebra line, just hoping some car will be kind enough to stop, and then quickly and carefully hurry across, giving a thankful smile. Even though I don't like that so much (I like walking too), it's better than here, where they suddenly walk almost blindly into the zebra line, not giving an ounce of thought to whether the cars coming will see you and have enough time to stop or not. Then give you the stink eye because you have to slam the brakes.
Even worse in the Nordic countries, where you will frequently experience idiots, often with headsets on too, walking forward on the sidewalk, then without any warning at all suddenly step out into the pedestrian crossing without even casting a glance backwards. "I have the right of way here. Don't you dare hit me for any reason whatsoever." Yeah, I'll be at fault (unless dash cam showing the idiot will serve as mitigating circumstances), but you'll be dead or in the hospital at best. You had the right of way though. Hooray for you.

I hear you about pedestrians. I spent most of my life driving in New York City. Between the entitled New Yorkers and the tourists looking up it was a miracle most days that I didn’t hit someone.

Regarding Pre Collision Alert it didn’t go off because you reacted before the idiot got in front of you.

From the Ford website:
The Pre-Collision Assist feature uses camera technology to detect a potential collision with a vehicle or pedestrian directly in front of yours during day or nighttime driving.

The system will assist you if you don’t notice a dangerous situation before it’s to late. In your case you reacted first.

 

[shogun32]

Two lane road through the city centre in the "morning rush". Left lane completely still

A 2-lane road means 1 lane in each direction. I assume you mean a 4-lane road. (Damn American Engrish, I know...)

Suddenly a dude walks out from between two cars into my lane (yes, on the pedestrian crossing).

How did you not see his head and shoulders over the cars he was walking between before he got to your lane? Tall vans? In any event, the sensors are incredibly crude and only respond to relative motion (object reflection getting shorter with each pulse interval - QED closing distance ) in the clear air in front of them.

Depending on where that sensor is aimed it may be picking up 'intermittent' signals as the legs swish. Plus humans are water-filled balloons and not exactly good signal reflectors.

 

[Bikeman315]

A 2-lane road means 1 lane in each direction. I assume you mean a 4-lane road. (Damn American Engrish, I know...)


How did you not see his head and shoulders over the cars he was walking between before he got to your lane? Tall vans? In any event, the sensors are incredibly crude and only respond to relative motion (object reflection getting shorter with each pulse interval - QED closing distance ) in the clear air in front of them.

Depending on where that sensor is aimed it may be picking up 'intermittent' signals as the legs swish. Plus humans are water-filled balloons and not exactly good signal reflectors.

True but not unexpected. Ford freely admits this:

*Pre-Collision Assist with Automatic Emergency Braking (AEB) can detect pedestrians, but not in all conditions, and does not replace safe driving. See your owner’s manual for system limitations.

 

[Vlad Soare]

Regarding Pre Collision Alert it didn’t go off because you reacted before the idiot got in front of you.

From the Ford website:
The Pre-Collision Assist feature uses camera technology to detect a potential collision with a vehicle or pedestrian directly in front of yours during day or nighttime driving.

The system will assist you if you don’t notice a dangerous situation before it’s to late. In your case you reacted first.

That's what they say, but in reality I've seen it react while I was already reacting. That is, I was already braking, but the car thought I wasn't braking hard enough, so it suddenly applied the maximum braking force. The amount of profanity that came out of my mouth as it did that would have made a cabman blush. Even I didn't know I could curse that badly.

 

[Bikeman315]

Need to change your avatar.

 

[Vlad Soare]

 

[shogun32]

I was already braking, but the car thought I wasn't braking hard enough, so it engaged and applied the maximum braking force

More "airbus" sh*t. Damn it you computer weenies (I R one) you're not in control, so f'off! I suspect the rate of rear-end collisions will go up considerably the more of these "the stupid programmer knows better than the driver" cars get fielded - just like what happened when red-light cameras got installed.

 

[Michael_vroomvroom]

A 2-lane road means 1 lane in each direction. I assume you mean a 4-lane road. (Damn American Engrish, I know...)

Nah, two-lane road. One in each direction.

How did you not see his head and shoulders over the cars he was walking between before he got to your lane? Tall vans? In any event, the sensors are incredibly crude and only respond to relative motion (object reflection getting shorter with each pulse interval - QED closing distance ) in the clear air in front of them.

Not sure why not. Possibly he was behind a small van and tree, possibly he was a hobbit, or possibly I was not paying enough attention to the side of the pedestrian crossing hidden by cars, but there he suddenly appeared, right in front of me.

 

[Qcman17]

Nah, two-lane road. One in each direction.



Not sure why not. , possibly he was a hobbit,.....

Maybe he was wearing the ring that made him invisible

 

[Bikeman315]

Not sure why not. Possibly he was behind a small van and tree, possibly he was a hobbit, or possibly I was not paying enough attention to the side of the pedestrian crossing hidden by cars, but there he suddenly appeared, right in front of me.

All of us believe that we always see everything all the time. Right up until we don't. Stuff happens.

 

[Torched10]

Surprisingly, when I go to the display it only gives me the option to turn it to low, there isn't an option to turn it off. Hopefully it won't be beeping all the time at the track.

If you're in track mode it turns itself off automatically according to manual.

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