Collision avoidance strategy
Sean_Q_
into oncoming traffic:
http://www.nationalpost.com/news/world/story.html?id=2253911
On a bike coming the other way, is this situation survivable?
Collision avoidance would require a fast mental calculation
of a space/time/velocity intersection problem, something like
an outfielder running to catch a fly ball. Except that
the baseball player has seconds to make the calculation;
a biker has only milliseconds.
I wonder if anyone has done a technical analysis. Say I'm riding
my S40 at 60 mph in the right lane of an undivided 4-lane highway
(2 lanes each way).
At any given moment there is a wedge-shaped area ahead of me with
the pointy end at my current position, representing my "volition zone"
(for lack of a better name) ie, all the points in two dimensional space
I can choose to ride through.
The faster I'm going, the narrower the wedge. However, its sides
may curve, and they change shape over time due to road geometry,
changes in speed (braking or acceleration), the presence of other
vehicles and the road shoulder.
The out-of-control cage is coming at me at an angle. It also has
a wedge-shaped possibility zone, but its movements are uncertain.
Actually its zone may not be a cleanly shaped wedge as the cage may
roll or hit another vehicle ahead of me; prior collision debris
also poses a threat.
The overlap of these two areas is the potential collision zone.
It looks roughly like a parallelogram, but with non-parallel edges.
Well, so far so good, but this is only a static 2-dimensional view.
What I really need is a something that includes time and collision
probability.
This would be a Collision Probability Map. It's 4-dimensional, making
it conceptually difficult. The axes (assuming polar coordinates)
are Bearing, Distance, Elapsed Time and Collision Probability.
The optimal collision avoidance strategy would be to choose any point
on this map where the collision probability is lowest. Preferably zero!
There are collision warning systems for aircraft. A mid-air collision
over Uberlingen, Germany in 2002 could have been avoided had the pilots
relied solely on these devices, but the local ATC overruled them:
http://en.wikipedia.org/wiki/2002_%C3%9Cberlingen_mid-air_collision
Would a similar system be feasible for bikes? Is civilian radar on
highways even legal? The annunciation would have to be very fast --
maybe a HUD showing the rider a continual threat assessment
in graphical form with recommended avoidance strategies.
SQ
'06 Zook S40 / '85 Dnepr MT-11 / various long-term low-payoff projects
S'mee
Easily...but I'll let you figure out HOW.
Datesfat Chicks
>
> There are collision warning systems for aircraft. A mid-air collision
> over Uberlingen, Germany in 2002 could have been avoided had the pilots
> relied solely on these devices, but the local ATC overruled them:
> http://en.wikipedia.org/wiki/2002_%C3%9Cberlingen_mid-air_collision
>
> Would a similar system be feasible for bikes? Is civilian radar on
> highways even legal? The annunciation would have to be very fast --
> maybe a HUD showing the rider a continual threat assessment
> in graphical form with recommended avoidance strategies.
The thoughts you pose are reasonable.
1)Radar is legal, subject to power and frequency restrictions. I don't know
if they are in production, but adaptive cruise control prototoypes would
determine distance to the vehicle ahead and adjust speed.
2)TCAS (you can look that up on Wikipedia) has a few advantages in operation
that you can't get in an automotive scenario.
First, there is the absence of other obstacles (just air and airplanes).
This turns it into a 3D problem with airplanes only.
Second, the time separation between airplanes is far larger than with ground
vehicles. Cars can easily be within a couple seconds of each other. Not so
with airplanes. This means for aircraft that you can devise a system that
relies on pilot action rather than automatic action. The pilots have time.
Phrased a bit differently, TCAS works because airplanes are already far
enough apart that one airplane can't progress from a normal trajectory to a
collision in a short period of time. Cars can. Imagine you're driving down
a 2-lane highway and another driver coming the other way decides to provoke
a serious accident. The time between when the vehicle is in a normal
position with no hint of abnormality and the collision would be under one
second. Not so with aircraft.
Nothing TCAS-like for cars would work because cars are too close together in
time. The collision avoidance would have to be undertaken automatically.
People aren't quick enough.
3)The Uberlingen crash was unfortunate. American air traffic control rules
say that TCAS has precedence over ATC (after all, TCAS is on the scene, ATC
is not). From memory, Uberlingen was really training error and/or crew
error.
Datesfat
The Older Gentleman
> It's every biker's nightmare: a car crosses a divided freeway
> into oncoming traffic:
>
> http://www.nationalpost.com/news/world/story.html?id=2253911
>
> On a bike coming the other way, is this situation survivable?
Hmf. I once had to avoid a motorist who appeared out of the rain,
driving on the wrong side of the dual carriageway. I swear my heart
stopped.
>
> Collision avoidance would require a fast mental calculation
> of a space/time/velocity intersection problem, something like
> an outfielder running to catch a fly ball. Except that
> the baseball player has seconds to make the calculation;
> a biker has only milliseconds.
>
> I wonder if anyone has done a technical analysis.
I'm sure the data to answer this is out there, though maybe not all in
one place.
--
BMW K1100LT Ducati 750SS Honda CB400F Triumph Street Triple
Suzuki TS250ER GN250 Damn, back to six bikes!
Try Googling before asking a damn silly question.
chateau dot murray at idnet dot com
oasysco
Gentleman) wrote:
> Sean_Q_ <no.s...@no.spam> wrote:
> > It's every biker's nightmare: a car crosses a divided freeway
> > into oncoming traffic:
>
> >http://www.nationalpost.com/news/world/story.html?id=2253911
>
> > On a bike coming the other way, is this situation survivable?
>
> Hmf. I once had to avoid a motorist who appeared out of the rain,
> driving on the wrong side of the dual carriageway. I swear my heart
> stopped.
Yeah, but's what the OP wants to avoid!
TOG@Toil
Details, details.... ;-)
Rob Kleinschmidt
> The out-of-control cage is coming at me at an angle. It also has
> a wedge-shaped possibility zone, but its movements are uncertain.
> Actually its zone may not be a cleanly shaped wedge as the cage may
> roll or hit another vehicle ahead of me; prior collision debris
> also poses a threat.
>
> The overlap of these two areas is the potential collision zone.
> It looks roughly like a parallelogram, but with non-parallel edges.
>
> Well, so far so good, but this is only a static 2-dimensional view.
> What I really need is a something that includes time and collision
> probability.
>
> This would be a Collision Probability Map. It's 4-dimensional, making
> it conceptually difficult. The axes (assuming polar coordinates)
> are Bearing, Distance, Elapsed Time and Collision Probability.
>
> The optimal collision avoidance strategy would be to choose any point
> on this map where the collision probability is lowest. Preferably zero!
Doesn't seem like it'd need to be a four dimensional map.
More like two dimensional + time = three dimensional.
A more common but similar problem is the left turn that cuts
you off. Do you try to go round the front, round the back
or perhaps turn hard right and try to parallel the car .
I've twice had to cross over the opposite lane and head to
the far shoulder. Both of these were really my own stupid
fault though. Also had to evade a few left turns, once by
steering behind and once by turning right myself.
Best question is probably whether the oncoming car is under
control or not and is the driver likely to be able competently
correct for the situation. My bet would generally be no, but
this might vary from one situation to the next.
Datesfat Chicks
news:1j9mh7n.cns743j5j5b8N%totallyde...@yahoo.co.uk...
>
> I swear my heart
> stopped.
A shame that it restarted.
Datesfat
The Older Gentleman
Twibil
>
>
> > Hmf. I once had to avoid a motorist who appeared out of the rain,
> > driving on the wrong side of the dual carriageway. I swear my heart
> > stopped.
>
> Yeah, but's what the OP wants to avoid!
So? Then don't ride motorcycles except maybe in the middle of dry
lakes on bright sunny days when you can see for 20 miles in every
direction.
Otherwise you will occasionally have a heart-stopping moment when some
doofus does something sudden and unpredictable right in front of you.
Ben Kaufman
>It's every biker's nightmare: a car crosses a divided freeway
>into oncoming traffic:
>
>http://www.nationalpost.com/news/world/story.html?id=2253911
>
>On a bike coming the other way, is this situation survivable?
>
>Collision avoidance would require a fast mental calculation
>of a space/time/velocity intersection problem, something like
>an outfielder running to catch a fly ball. Except that
>the baseball player has seconds to make the calculation;
>a biker has only milliseconds.
If all you have is milliseconds then your fate is already sealed by physics.
I greatly doubt it. An airplane may be traveling 10 times faster than a car but
the safe distance between aircraft in "opposing" lanes is set at 100 to
1000 times greater than between cars so there is much more time to react and
decide what to do. Additionally, the aircraft has more degrees of freedom and
much less likely it will be "boxed in" by nearby aircraft.
Datesfat Chicks
> Datesfat Chicks <datesfa...@gmail.com> wrote:
>
>> "The Older Gentleman" <totallyde...@yahoo.co.uk> wrote in message
>> news:1j9mh7n.cns743j5j5b8N%totallyde...@yahoo.co.uk...
>> >
>> > I swear my heart
>> > stopped.
>>
>> A shame that it restarted.
>>
> Oh dear. And what prompted that observation?
Your posts on this newsgroup.
Datesfat
BrianNZ
>
> "The Older Gentleman" <totallyde...@yahoo.co.uk> wrote in message
> news:1j9nfi6.yatb9em6eao0N%totallyde...@yahoo.co.uk...
>> Datesfat Chicks <datesfa...@gmail.com> wrote:
>>
>>> "The Older Gentleman" <totallyde...@yahoo.co.uk> wrote in message
>>> news:1j9mh7n.cns743j5j5b8N%totallyde...@yahoo.co.uk...
>>> >
>>> > I swear my heart
>>> > stopped.
>>>
>>> A shame that it restarted.
>>>
>> Oh dear. And what prompted that observation?
>
> Your posts on this newsgroup.
>
> Datesfat
So injury, disfigurement or death is bad for a thief, but you wish death
upon a person for his comments?
A very selective definition of 'freedom of speech'
Sean_Q_
> Doesn't seem like it'd need to be a four dimensional map.
> More like two dimensional + time = three dimensional.
The collision probability is the dependent variable; ie the value
that I want to determine. The other 3 variables are the ones I get
to choose. That's why I called it a 4-dimensional map.
However, I control distance and time only indirectly, via my brakes
and throttle (assuming the effects of steering on these two is
negligible). Therefore it might be more useful to define these
contributing variables in terms of controls that I manipulate
directly: steering, brakes and throttle.
Or just steering + acceleration, where acceleration is a signed quantity
(negative = brakes, positive = throttle).
Starting with the simplest case for the sake of argument, I'm on
a paved, two-lane country road. One lane each way. Say there's a guard
rail on my side or a steep bank so escaping off-road to the right
is not an option. (Any Brits, Kiwis, Ozzies etc if you're there please
read this through a mirror).
These conditions severely limit steering as an factor so it becomes
basically a 2-dimensional map. The X axis is acceleration. The Y axis
is collision probability ranging from 0 (on the X axis) to a maximum
value of 1.
As a guess, a typical probability curve might be skewed like this:
http://billkosloskymd.typepad.com/photos/uncategorized/2007/09/20/skewneg.gif
Let's say an oncoming car veers into my lane such that if I take
no evasive action the collision probability is 1 (ie, certain).
This is the vertical line on the graph labeled "mode", where
acceleration X = 0.
The graph for this case says that if I speed up the collision
probability drops off rapidly with increasing acceleration.
This makes sense, because if I can cross the car's path
ahead of the car, I'm safe pretty well no matter what
the car does (unless the driver is a homicidal psycho doing
a U-turn to come after me).
If I choose to brake the odds for survival are less (graph
tapers slower). It isn't safe anywhere in the car's range of
possible routes.
On a two-lane road the best strategy might be to punch the handlebars
sharply to the right so as to fall off on a hard left turn and head
for the weeds on the other side or recover on the shoulder.
A risky maneuver, but I'm already at risk. Hopefully I have
enough situational awareness of other nearby traffic to avoid
any third parties.
SQ
The Older Gentleman
> "The Older Gentleman" <totallyde...@yahoo.co.uk> wrote in message
> news:1j9nfi6.yatb9em6eao0N%totallyde...@yahoo.co.uk...
> > Datesfat Chicks <datesfa...@gmail.com> wrote:
> >
> >> "The Older Gentleman" <totallyde...@yahoo.co.uk> wrote in message
> >> news:1j9mh7n.cns743j5j5b8N%totallyde...@yahoo.co.uk...
> >> >
> >> > I swear my heart
> >> > stopped.
> >>
> >> A shame that it restarted.
> >>
> > Oh dear. And what prompted that observation?
>
> Your posts on this newsgroup.
>
Jolly good. Well, you can join KrustyUS and Don in the delusional
corner.
S'mee
wrote:
> "The Older Gentleman" <totallydeadmail...@yahoo.co.uk> wrote in messagenews:1j9nfi6.yatb9em6eao0N%totallyde...@yahoo.co.uk...
>
> > Datesfat Chicks <datesfat.chi...@gmail.com> wrote:
>
> >> "The Older Gentleman" <totallydeadmail...@yahoo.co.uk> wrote in message
> >>news:1j9mh7n.cns743j5j5b8N%totallyde...@yahoo.co.uk...
>
> >> > I swear my heart
> >> > stopped.
>
> >> A shame that it restarted.
>
> > Oh dear. And what prompted that observation?
>
> Your posts on this newsgroup.
Then I suggest you leave little OCD boy...you obviously don't have
enough (much less thick enough) hide to be here. Go hang out in one of
those little moderated forums where little real info is shared and
everybody is a goooood sheeple, just like your spineless gutless self.
S'mee
> >news:1j9nfi6.yatb9em6eao0N%totallyde...@yahoo.co.uk...
> >> Datesfat Chicks <datesfat.chi...@gmail.com> wrote:
>
> >>> "The Older Gentleman" <totallydeadmail...@yahoo.co.uk> wrote in message
> >>>news:1j9mh7n.cns743j5j5b8N%totallyde...@yahoo.co.uk...
>
> >>> > I swear my heart
> >>> > stopped.
>
> >>> A shame that it restarted.
>
> >> Oh dear. And what prompted that observation?
>
> > Your posts on this newsgroup.
>
> > Datesfat
>
> So injury, disfigurement or death is bad for a thief, but you wish death
> upon a person for his comments?
>
Just proves he's either a commie or a socialist....never could see a
difference between the two.
c
> On a two-lane road the best strategy might be to punch the handlebars
> sharply to the right so as to fall off on a hard left turn and head
> for the weeds on the other side or recover on the shoulder.
>
> A risky maneuver, but I'm already at risk. Hopefully I have
> enough situational awareness of other nearby traffic to avoid
> any third parties.
>
> SQ
1) you wouldn't really rather be flattened and squished than perhaps
flying a bit and landing?
2) could you even do that? short of approaching a cliff, could you
ever willfully put your bike down at speed, flattening yourself?
you know some of this is just luck ... the rest is what's between your
ears, and you just have to do yer best ...
Datesfat Chicks
> Datesfat Chicks <datesfa...@gmail.com> wrote:
>
>> "The Older Gentleman" <totallyde...@yahoo.co.uk> wrote in message
>> news:1j9nfi6.yatb9em6eao0N%totallyde...@yahoo.co.uk...
>> > Datesfat Chicks <datesfa...@gmail.com> wrote:
>> >
>> >> "The Older Gentleman" <totallyde...@yahoo.co.uk> wrote in
>> >> message
>> >> news:1j9mh7n.cns743j5j5b8N%totallyde...@yahoo.co.uk...
>> >> >
>> >> > I swear my heart
>> >> > stopped.
>> >>
>> >> A shame that it restarted.
>> >>
>> > Oh dear. And what prompted that observation?
>>
>> Your posts on this newsgroup.
>>
> Jolly good. Well, you can join KrustyUS and Don in the delusional
> corner.
BTW, you should know that I was just clowning around (i.e. I'm not serious
and my feelings don't go in that direction at all). I appreciate all of
your good advice over the past couple of years.
But "my heart stopped" just seemed to be crying for that kind of acidic
reply. I couldn't help myself.
Take care,
Datesfat
Datesfat Chicks
news:f662b680-9cc3-4d4a...@z10g2000prh.googlegroups.com...
To the best of my knowledge, TOG has not hired you as an apologist.
You sticking up for him like that only convinces me that you have the hots
for him and are trying to impress him. I suggest you get him some candy and
flowers and tell him how you feel.
Datesfat
Leszek Karlik
<datesfa...@gmail.com> wrote:
[...]
> You sticking up for him like that only convinces me that you have the
> hots for him and are trying to impress him. I suggest you get him some
> candy and flowers and tell him how you feel.
You're trying to write caustic usenet posts.
How cute :-)
--
Leszek 'Leslie' Karlik
NTV 650
Twibil
wrote:
>
>
> To the best of my knowledge, TOG has not hired you as an apologist.
Idiosyncrasies aside, it's called "having friends".
Should you ever have one (oh unlikely thought) you'll come to
understand.
S'mee
wrote:
> "S'mee" <stevenkei...@hotmail.com> wrote in message
>
> - Show quoted text -
Your pathetic attempt at humour is noted. Now take your ocd meds and
go to bed little boy...the adults are talking.
S'mee
You use your words better than $20 whore sir! 8^)
Stephen Cowell
"Sean_Q_" <no....@no.spam> wrote
> Rob Kleinschmidt wrote:
>
>> Doesn't seem like it'd need to be a four dimensional map.
>> More like two dimensional + time = three dimensional.
>
> The collision probability is the dependent variable; ie the value
> that I want to determine. The other 3 variables are the ones I get
> to choose. That's why I called it a 4-dimensional map.
I have visions of jumping up on the seat, then being
propelled through the air above the mess below...
of course, shit happens way too fast, and you end
up where you end up... awake or (most likely) not.
If you have young children, and aren't wearing a
full-face helmet, you are a fool and an idiot.
IMO, of course.
Saw another ugly orange spray-painted roadkill
puzzle on the way to work today... big MPOI
(motorcycle point-of-impact) circle, other strange
graphics... scratches and fluid stains on the tarmac.
They don't pull out the spray paint unless someone
dies.
There's a cross added to the one on April 20th I
posted about... it says 'Hang Up... Save A Life'.
Was a cellphone involved? Is it morbid to wonder?
Fuksake, be safe. Happy Turkey. Enjoy whatcha got.
__
Steve
.
Twibil
>
>
> You use your words better than $20 whore sir! 8^)
There, there, Taggart: just flaming a man and a horse...
The Older Gentleman
> But "my heart stopped" just seemed to be crying for that kind of acidic
> reply. I couldn't help myself.
Ah!
S'mee
Right sir...obtw YOU can find that damn frog yourself this time.
Twibil
>
>
> Right sir...obtw YOU can find that damn frog yourself this time.
Daddy *loves* his Froggy!
S'mee
<drag out paper and pen>
could you say that again? <GR&RLH>