Re: Riding up front?

Keane wrote:
On Wed, 22 Jul 2009 09:10:36 -0500, Rudeney <rudeney@xxxxxxxxxxxxxx>
wrote:

Keane wrote:
On Sun, 19 Jul 2009 23:49:40 -0500, Rudeney <rudeney@xxxxxxxxxxxxxx>
wrote:

It also seems to me that a comparatively insignificant investment in sensors and computer software could create a system that to keep track of the exact location and velocity of each train and alert a controller (or even shutdown the entire system) in the event of an impending collision.
Insignificant investment for a real-time telemetry acquisition system?
You can't be serious. This isn't Test Track. It's miles of beam.
But those miles of beam are already wired. I'll bet that there's a not very expensive way to monitor a train's location based on electrical load and resistance along the power supply lines.

That's still not going to tell you speed or direction.

But it could report velocity because the load and resistance at each point on the track will be constantly changing. Yes, this might require the addition of some sensors along the beams, but it wouldn't have to be one every inch or anything crazy liek that. It might just need to be one every hundred yards, and then mounted on the electrical feed instead of the beam. I know it can work, I just don;t know how accurate or expensive it would be. It's just a "brainstorm".

You're either
going to have to have some sort of a RFID or GPS system to do that.
(Or you can have the monorail itself transmit telemetry data.)

Even if each train was transmitting real-time telemetry data, the cost to build such as system is still not that expensive. I'll bet I could do it for $2M or even less. In terms of spending on safety, especially if you put it into terms of future wrongful death or injury settlements, that would be pocket change to The Mouse.

There are a half dozen cars on the market that, for less than $100K, can do this with their cruise control systems, so why can't the Monorail system handle it?
How would this have prevented the accident?

Avoidance collision systems are front mounted.
So mount the sensors on both front and back.

I've always wondered what happens when an ACS meets an ACS.
Assuming they operate on the same frequencies, do they interfere
with each other?

They do not interface. They may share a frequency, but they use unique digitally encoded signals.

It compares a radar
image to your speed delta. The monorail that caused the accident
was moving backwards, using an override, which probably would have
overridden the collision system. That's what overrides are for.
Understanding the way PRE-SAFE works, I don't see a reason to ever give the driver a way to disable it. If it determines that it's too late (within milliseconds) for the driver to react and apply the brakes to avoid a certain collision, it intervenes. Since it can apply the brakes with a shorter reaction tine than a driver, it can actually avoid the accident. Remember, this isn't like with cars on the open road where one can pull into your lane unexpectedly. These are rail trains so there is either another train on your rail or not.

Heavy rain will disable such a system. (So will snow, but heaven
forbid it snow that hard in Orlando... :-))

Actually, rain is not so much an issue.

Straight beam applications like Radar don't work well around
curves, either.

They typically use three sensors so they get a "doimensional" view of the track. PRE-SAFE can tell a car in the lane ahead from one in an adjacent lane, a low overpass ahead, a cup in the road, etc.

The logic of the system either sees an imminent collision and intervenes, or not. I cannot think of a single situation where you'd actually want a Monorail to collide with another train.

No, but you'd have to disable it (or have an override) for entering
stations, and even the hotels. They'd all look like *huge* monorails
sitting on the track.

Again, the system I am familiar with (PRE-SAFE) would not have that problem. It can actually "see" the difference.

This was at night. If you see some big honkin' headlights in the
camera behind you as you're backing up, you stop. :-)

But could a driver, looking in a small monitor or mirror, differentiate headlights on the same beam vs. an adjacent one? Liek I;ve been saying, properly designed ACS systems can.

(And there is no safety system that can correct for every driver
error.)

Nope, but to have a safety system that has to be disabled to perform a normal operation seems ludicrous.

Keane, who has to leave for another of those wonderful spinal taps...

I hope that all goes well.

--

- RODNEY

Next WDW Vacation?
Who knows!


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