

Elevator Dispatch Algorithms - kumarski
http://www.smartplanet.com/blog/pure-genius/intelligent-elevators-answer-vertical-challenges/8191

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peter_l_downs
Very cool. It's interesting to note that Elevator Dispatch Algorithms are very
similar to harddisk read/write algorithms. Hard drives have to accept read
("pick up") and write ("drop off") requests at different disk addresses
("floors") and figure out the most efficient way to handle all of the
requests. In this analogy, traditional hard disks are simply very, very tall
buildings wrapped around a cylinder.

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shabble
So much so that the classic (spinning platter) disk scheduler is named 'The
Elevator Algorithm'[1]

[1] <https://en.wikipedia.org/wiki/Elevator_algorithm>

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wtracy
That's actually what I expected this article to be about!

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cullenking
My dad is an elevator mechanic and just recently switched from Schindler to
Thyssen Krupp. It's always boring to go see him at work now - all the new
buildings as well as the modernized old buildings are almost exclusively
switched over to digital systems. The old systems are incredibly interesting -
huge cabinets full of relays! The smell of ozone and the sound of thousands of
relays clicking in consortium is really enjoyable to see. Imagine the relay
computer videos that come across here on occasion, but put in ten large
cabinets of the relays and you get an idea of the sound.

Of course, touch the relay without a relay pick and you'll get a 120v shock :)

The stuff put together in the 80's is a combo of relay logic and old school
processors, where you get to load the program in using paper tape!

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alexsb92
Do you know of any videos where we can hear the sound of that many relays? I
believe i've heard sounds similar to what you are describing in movies, but
I'm not sure if those were the same thing, or if they were accurate.

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ewang1
<http://youtu.be/gBr3RHhTpPk?t=1m9s>

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cullenking
Nice find - now imagine a machine room for a bank of 10 elevators :)

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mbrameld
When I was a kid my father worked for Southern Bell. I used to go in with him
on trouble calls to the local office and it was a building full of rows and
rows of relays like those. Smelled awesome.

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Falling3
What's funny is just how simple these algorithms are. All it really took was
something looking at this from a slightly different perspective.

The best optimizations I've done at my job have been exactly that. Looking at
things a little differently and even removing steps. It's really a testament
to open-mindedness and creativity.

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femto
Here is my favourite elevator optimisation story [1]. Customers were
complaining that the lifts were taking too long to arrive. It turned out the
root problem was boredom, and the solution was to install mirrors in the
lobby. The mirrors allowed people to fill in the time by admiring themselves
and others. A neat illustration of how there are sometimes simple non-
engineering solutions!

[1]
[http://books.google.com.au/books?id=xyIRdiAbpr8C&lpg=PA1...](http://books.google.com.au/books?id=xyIRdiAbpr8C&lpg=PA16&ots=F6LghCJrb7&pg=PA16#v=onepage&q&f=false)

\--- Update: Q: Have I been suckered by an urban myth here? I have a vague
recollection of knowing this story before the publication date of the source I
gave, and it seems to be well used in "management" books but no mention of
specifics or a primary source.

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nodata
The book might be called "Are Your Lights On? How to Figure Out What the
Problem Really Is"

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femto
Further poking around comes up with an article that claims the story
originates with a consultant friend of Russell Ackoff (the author of the book
I linked to), and took place in a New York hotel in 1955. A bit more specific,
but I'm still a bit suspect since Ackoff doesn't seem to mention these details
in his writing. Presumably if it is mentioned in the earlier book that you
point to, Ackoff must have published or mentioned it elsewhere. I've done this
one to death now, so I think I'll move on.

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simcop2387
So how long before they can predict the future to be at the right place at the
right time every time?

It's certainly how interesting how critical a good setup can be to get a large
skyscraper to actually work well. If they take too long to get to the people
waiting then they need to leave or get to work. The old game SimTower is
actually a pretty decent simulation of this kind of effect (if not still
overly simplified).

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rmserror
SimTower was /actually/ just built around an elevator simulator. "You guessed
right," she said. "Sim Tower was built around a real elevator simulation
program we bought from a Japanese guy."
[http://www.gamasutra.com/view/feature/2150/the_designers_not...](http://www.gamasutra.com/view/feature/2150/the_designers_notebook_the_.php)

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mprovost
In the early 90s I did a high school science project at a research lab that
was working on a smart elevator project for Otis. Everyone had a NeXT
workstation and a Symbolics LISP machine. And they wore ties. It's hard to
imagine getting a job now where you would get that much money spent on your
computers. Most people are lucky if they get two screens.

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darklajid
Actually I'm surprised by the praise. This kind of elevator isn't uncommon
here, both in towers and hotels. And it makes so much sense.. In both
scenarios you probably want some kind of access restrictions, be it 'You work
on floor 10 so that's where you can go" or "You can go to the cafeteria on the
top or the floor of your room".

This system, the way I know it, solves both this problem and allows the
elevator software to plan ahead.

Side note: Paternoster are quite cool. I prefer them to most 10-20 year old'
real' elevators.

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mherdeg
Paternosters scare me because of <http://i.imgur.com/MgRFK.jpg>

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mmphosis
elevator UI

 _the Miconic 10, a smart elevator system that allows users to enter their
floor onto a keypad._

 _"The first U.S. installation of Miconic 10 was at the Ameritech building in
Indianapolis in 1993. The next generation added a radio frequency
identification, or RFID, reader to the keypad to identify passengers, so
tenants could swipe their ID badge or card to call an elevator. In 2009,
Schindler launched the third generation, called PORT (it stands for “Personal
Occupant Requirement Terminal”), a software-driven system that uses a touch-
screen and learns movement patterns, enabling it to personalize its offerings
to each passenger._

I was just at a hotel where I had to:

    
    
       1.  press the up button
       2.  swipe a room (key) card on the elevator
       3.  often swipe again because the card needs to swipe a certain way, swipe for other people who were equally confused
       4.  press the floor number(s)
    

versus

    
    
       1.  press the up button
       2.  press the floor number
    

I would imagine that guests would have a room (key) card with RFID, and that
by default the lobby elevators would read the card and by default offer to go
to the floor that the room is on, and from the room floor elevators it would
by default offer to go to the lobby. The "keypad" or touchscreen would only
need to be used if you wanted to go to another floor: pool, restaurant,
conference room, etc...

The elevators need to clearly indicate where they are going.

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darklajid
At work:Six elevators, two (?) panels per floor. If you come near one of these
panels it lights up and offers a touchscreen with all possible floors. By
default the lobby and the parking deck. If you swipe your access card in front
of that panel, the selection is expanded to include the floors you're cleared
for. Select a floor and you'll be told which elevator door is going to open.

So: For leaving the building: One press. For your way up to work. Swipe,
press.

Up and down buttons are idiotic if you specify the floor anywhere..

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xmpir
we are fine with our old-school 20th century (contructed 1980) elevator. i
don't like the idea of the elevator knowing who i am.

but that could be a nice part of ocean's fourteen... hack the elevator!

