Re: Riding up front?

"Rudeney" <rudeney@xxxxxxxxxxxxxx> wrote in message
news:h4202l$r1v$1@xxxxxxxxxxxxxxxxxxxxxxxxx
Yep, and a more sophisticated version of that system uses front-mounted
sensors that are connected to the cruise control. You can then set it to
"pace" the car ahead of you at a safe distance. These systems have been
in place on luxury cars for years, but they are making their way to to
mainstream brands. The latest implementation of this technology will not
only alert you that you are getting to close to other cars when driving
(not just parking, but at highway speeds) but it can also intervene and
apply the brakes to avoid a collision. If the computer system determines
that a collision is imminent and unavoidable, it will then do things like
close all windows and the sunroof, unlock the doors, and pretension the
seatbelts and move seats and headrests into the safest positions. Some
systems even have special bumper mechanisms that are extended to add more
energy absorption during the crash. Again, this sort of technology is
available on consumer automobiles that sell for around $100K.


True. But any kind of active sensors, whether they be radar, motion, etc
would at best only be able to lessen an impact only slightly. Just last
night I read that the stopping distance under full emergency brakes of an
*empty* monorail train going 40MPH is approximately 300 feet. A loaded train
would obviously take longer. And a monorail can't swerve like a car can.
I don't think any kind of automobile collision-avoidance system available
out there is capable of detecting objects that far away. Parking sensors are
dealing with maybe 10 feet. Sensors used while driving are only detecting a
car-length or two away.

Plus, how would such a system be able to differentiate a stopped train on
the beam in front of you from an oncoming train along the TTC/Epcot stretch,
where the trains are separated by only a few feet laterally? You'd have to
dial the detection zone so narrow that it would become entirely ineffective
on curves.

But I do agree that a GPS-based system would be a start, at least for
relaying train locations to a central location, perhaps as a supplemental
screen on the console of each train. A red MAPO would automatically bring
that screen up. Perhaps also display whenever the MAPO override button is
being pressed.
But again, systems like that aren't infallible, and I wouldn't want to give
it automated control of the train. The distance between the beams on the
TTC/Epcot run is probably within the margin of error for most GPS systems.
Throw in a cloudy day with lowered satellite communication, and all of a
sudden you have a train slamming on the E-brakes from full speed because it
thinks that the approaching train going in the opposite direction suddenly
jumped onto its own beam.

I don't recall if I mentioned it on here or in another forum, but I do think
that the lack of MAPO transmitters on the spur lines should be re-thought.
Perhaps install transmitters that put out a signal so the train specifically
knows it's heading for a spur beam, eliminating the need for the MAPO
override. Also, in addition to the current speed limitation while using MAPO
override, perhaps install limits to its use, either time or distance. Thus,
the MAPO override can ONLY be used to drive the distance it would take to
get through a switch that's causing the MAPO system to get mixed signals.
You then have to come to a full stop before engaging the override again.
MAPO transmitters would then allow regular driving on the spur lines,
without the need to start-stop-start-stop all the way to the shop.

-Rob




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