Brake Force Display Brake Lights?

[Dangermouse]

Twenty years ago I had an idea that brake lights could be arranged to light up progressively depending on how hard the driver was pressing on the pedal. The harder the driver pushed, the brighter the brake lights. I even considered patenting the idea if it hadn't already been done, but upon a cursory check I found that BMW had beaten me to it.

So I waited for this idea to come to market. I consider myself a car guy, subscribe to magazines, work on my own cars, that sort of thing, and am generally aware of technology available in most cars, so I was surprised to find out yesterday that BMW have been offering what they call Brake Force Display (BFD) on cars since 2004. And perhaps their competitors do also. How did I miss this?


Rather than monitoring the brake pedal position, their system monitors the cars deceleration via the ABS sensors and at rates higher than -5.0m/s2 the secondary "panic" brake lights are activated (these are either a completely separate brake lamp on cars with incandescent lighting or a supplementary set of LEDs on newer cars). Having read all this, I honestly don't recall seeing any cars brake lights do this.


Anyway, this got me thinking about our cars rear end and how low it is. It is generally accepted that the addition of a center mounted brake lights (CHMSL) is a good idea, but I was wondering how one could add an additional element for Brake Force a.k.a. Panic Braking. Some form of pressure pad under the pedal? A linear actuator to measure pedal position?

You could sacrifice one of the pairs of brake-lights and convert it to a BFD light, or make the CHMSL flash.

Has anyone looked into this? Thoughts? Not worth the effort?

[Ron]

Interesting!

I see our taillights being "low" but not "too low", but that's a cool idea! I like adapting to the CHMSL best, of the two. Maybe use a cheap G-Force meter/switch and thank them for doing the math already. (...wouldn't matter if you were accelerating backwards that hard ;-)
I remember seeing a BMW with brake lights that made me think he went overboard with LEDs... Could be it's easy to miss it being a BFD if you had not been following long enough to notice a difference... ( Lack of public education ;-)

[vwdmc16]

Ive heard about that on bmws, however even though i am a professional bmw mechanic, i have never seen one illuminate extra lights.

[Dangermouse]

Well thankfully I am not alone in my ignorance.

Chris, I know the E83, at least, has a separate bulb for this function. It's also used as a back up bulb for when the regular brake light bulb burns out.

[SS Spoiler]

I remember J C Whitney used to sell a small traffic signal light for your back window shelf. When you pressed on the gas the green light glowed, let off the gas [coasting] the amber light glowed and step on the brake the red light glowed. It let the driver behind you know exactly what you're doing. I still think it was a good idea.

[DMCMW Dave]

I remember J C Whitney used to sell a small traffic signal light for your back window shelf. When you pressed on the gas the green light glowed, let off the gas [coasting] the amber light glowed and step on the brake the red light glowed. It let the driver behind you know exactly what you're doing. I still think it was a good idea.

The also sold a stuffed white cat with eyes that lit up with the brake lights and turn signals. It was not such a good idea.

Only old guys will remember this.

22036

[Dangermouse]

Good grief Charlie Brown!

I suddenly want one.

[Tillsy]

The also sold a stuffed white cat with eyes that lit up with the brake lights and turn signals. It was not such a good idea.

Only old guys will remember this.

22036

Bwahahaha - that's awesome :hysterical:

[vwdmc16]

The also sold a stuffed white cat with eyes that lit up with the brake lights and turn signals. It was not such a good idea.

Only old guys will remember this.

22036

I built a race car with a guy that loved stuff like that. He made a quick how-to make one of those too.

http://jalopnik.com/238353/if-you-cant-buy-it-build-it-wanky-the-safety-cat

[Bitsyncmaster]

The also sold a stuffed white cat with eyes that lit up with the brake lights and turn signals. It was not such a good idea.

Only old guys will remember this.

22036

I remember those and the head would bob up and down. A little before the fuzzy dice hanging from the rear view mirror was cool.

[Dangermouse]

I built a race car with a guy that loved stuff like that. He made a quick how-to make one of those too.

http://jalopnik.com/238353/if-you-cant-buy-it-build-it-wanky-the-safety-cat

Man, that would be disturbing to follow on a dark night

[OverlandMan]

Not trying to make this into a Winky thread but I did see this on eBay after reading this thread: http://www.ebay.com/itm/WINKY-CAT-NEW-Sits-on-package-shelf-Eyes-light-with-brake-lights-/321209296880?pt=Vintage_Car_Truck_Parts_Accessorie s&hash=item4ac990e7f0&vxp=mtr

It appears to be a repro and certainly not as cheap as the <$6 one in the catalog back in the day.

[jangell]

Progressively lighting up brake lights is an interesting idea, although i think it would need to be separate lights -- simply making the lights brighter would probably not be obvious to other drivers, unless they saw the change in intensity as it happened. Meaning, I'd think it would be too subtle. You could make it so that at normal braking the light is fully lit, and have panic braking make the bulb super-bright, but I don't think that would necessarily be obvious to other drivers either.

I found some videos of the BMW system, which seemed to rely on an additional brake light (at least in the videos I found). That makes more sense than just making the existing lights brighter, as the brightness may be too subtle to read clearly. It also seemed to have three levels: Normal brake lights, normal lights plus the secondary brake lights, and normal lights plus the secondary lights plus flashing the HCSL (or reverse lights in one of the videos) at a rate of one or two a flashes a second. It seemed to keep them light/lights flashing even after the car had come to a complete stop.


I once saw a somewhat similar implementation on a motorcycle: when hard-braking, the brake light flashed quickly three times (strobed, really, taking less than a second for all three flashes), then stayed illuminated as a normal brake light. The quick flashes draw your attention to the vehicle, and the fact that it's the brake light made it clear that it was with regards to braking.

I also recall seeing a brake light with a built-in strobe on a truck. When the brakes were applied, the red strobe would flash once as the normal brake lights came on. It did this every time, though, not just when during a panic-stop. That seemed a bit more distracting, but it was probably done to keep people from crashing into the back of these specific trucks for whatever reason.

I haven't seen either of these since.


One method I'd been considering was using a cheap accelerometer (like in a cell phone) to trigger the "strobe three times" brake light method (likely with LED bulbs; incandescents likely aren't fast enough) when the brake pedal was pressed. Or maybe keep strobing until the G forces drop below an acceptable threshold (or until the brake is released). I'll have to get around to doing that someday...

-- Joe

[DMCVegas]

Man, that would be disturbing to follow on a dark night

You ain't seen nothing!


http://www.youtube.com/watch?v=Citgm1OHXE0#t=29

And right here (http://jalopnik.com/5387975/make-your-own-animatronic-screaming-skull-brake-lights-with-junkyard-parts) are the instructions and schematics on how to build your very own.

[Tillsy]

I once saw a somewhat similar implementation on a motorcycle: when hard-braking, the brake light flashed quickly three times (strobed, really, taking less than a second for all three flashes), then stayed illuminated as a normal brake light. The quick flashes draw your attention to the vehicle, and the fact that it's the brake light made it clear that it was with regards to braking.

There are brake lights available that do that - quickly flash a few times before illuminating normally. Nothing to do with hard braking, does it every time as a means to get attention.

[jangell]

Ah, ok. I didn't think it was triggering every time, but it did seem frequent; I may have just misread what the motorcyclist was doing or something.

-- Joe

[Dangermouse]

There are brake lights available that do that - quickly flash a few times before illuminating normally. Nothing to do with hard braking, does it every time as a means to get attention.

I've seen that on some Hondas. Don't know if it was an option when buying or not. It was just the CHMSL that flashed, but I certainly noticed it while following the car.

Flashed 4 or 5 times and then stayed on steady.

[vwdmc16]

You ain't seen nothing!


http://www.youtube.com/watch?v=Citgm1OHXE0#t=29

And right here (http://jalopnik.com/5387975/make-your-own-animatronic-screaming-skull-brake-lights-with-junkyard-parts) are the instructions and schematics on how to build your very own.


Ha that was made by my friend Phil too.

[DMCVegas]

I've seen that on some Hondas. Don't know if it was an option when buying or not. It was just the CHMSL that flashed, but I certainly noticed it while following the car.

Flashed 4 or 5 times and then stayed on steady.

That was a limited-time factory option. Honda, Toyota, Mercedes, and I think Saturn had them, but only for a couple of years. I, for one, absolutely hated this feature! It always looked like someone was trying to brake-check you, so you never knew if they were road-raging you or what. It was only out for a couple of years, because actually it's illegal according to the DOT here in the U.S.

If you're a bit more curious about this little footnote in automotive history and culture, have a look here. (http://regulations.justia.com/regulations/fedreg/2005/05/23/05-10136.html)

On a side note, when we bought our truck the dealer installed a license plate frame that included a flashing stop LED brake light that does the same thing. Now this set up never bothered me, and I like seeing it on other cars from the same dealer that I've been behind. I'm thinking that in addition to the CHMSL on the D that I currently have, I might just install something similar between the license plate lights on the rear end.

[Starglider]

I've added fog lights to the lower rear fascia, using LEDs and a couple of lenses from some defunct DMC-12 tail light units. It's a UK legal requirement but I get hardly any use out of fog lights in normal driving, so it's an interesting idea to trigger them on hard braking as well. Will have to look into it.