Suggestion from Patrick to Mike!

[u2205]

Mike asked me to post these at the Mochizuki so he could remember them!

The one that I thought of was to limit each elevator at the Double Tree to only 5 floors each to make the access quicker!

An addition that I think is really critical to the sound system is the dbx 120A. What is does takes the lowest notes of the sound (120Htz and below) and puts them an octave lower. This makes the bass at the raves and concerts much more "pumping" and the sounds doesn't have to be near hearing loss levels!

[JeffT]

One thing that makes many elevator systems amazingly slower is a long delay before the doors close after the floor has been selected, or after the person exits at a floor. This was a significant factor at the 2007 hotel. It might have been at the Doubletree in 2005, too, but my memory is a little fuzzy. This is likely a configuration setting that can be changed by the elevator operator, so talking to the hotel about it is a possibility. This, if possible, is a free way to increase the speed of the system without any actual mechanical changes (changes to motor speed, acceleration, even door motor speed). However, hotels may deliberately keep this value high to make it easier for people using luggage carts.

Limiting floors of the elevators might work, but the elevators won't "know" about this when they stop to get people going down, so I'm not sure how much it will help. It might be worth trying.

The ideal elevator system increases efficiency immensely by doing three key things:

1. The floor is selected on the outside, when calling the elevator. This allows the computer to group passengers in cars by floor. After pressing a button to choose a floor, a display next to the button tells you which car you are assigned to and you go wait by it. There are no floor buttons inside the elevator. If you accidentally enter the wrong elevator, you are forced to exit at some other floor, but then you can choose your floor again. When an elevator stops, a panel above each car lists the floors that it is heading to. This is also displayed on the inside.

2. The scheduling computer attempts to minimize the sum of the squares of the passengers' estimated waiting time (time from floor selection to arrival). Squaring the value prevents "starvation", a technical term essentially meaning that an individual passenger cannot be "sacrificed" to make everyone else's trip a bit shorter. (So it cannot, say, ignore all passengers on a certain floor to make everyone else's trips collectively a little shorter.)

3. The system uses traffic patterns from previous days, weeks, months, etc., as well as the current activity levels in the last few minutes, to predict current activity levels in the next few minutes. This helps the scheduling algorithm. For example, at certain times of the day, certain floors might be busy as starting floors, and at other times, as destination floors.

These elevator systems are still rare, likely because they are expensive, but there are a few hundred of them installed throughout the US.

[JeffT]

I don't know about the Double Tree spicifically, but I know that most elevators can be programmed to only stop at certain floors.

Oh I see what you're saying...do it automatically rather than having volunteers direct people. That's definitely something we can check into.

[Mr_Phelps]

Thanks, by the time I got home I had forgotten about that.  At least the equipment made it back to the locker!

We will need to chat with the hotel about the elevators also.  They may have some method in place already when large events are in the hotel.  I'm wondering how much just controlling the access at the lobby would impact things.  Or maybe putting up signs for ouir attendees to please use certain elevators at certain floors.  Just have to find out what the hotel would go for.

Still, it was a great idea Mr_Mustash!

[JeffT]

Thinking this through, I don't think it will work. It's probably not possible to set the elevators this way given the current configuration. When you call the elevator from the first floor, there would be no way for the computer to know which floor you want to go to; hence, which car to respond to the call. The only way it would work is if all the cars idled at the first floor with the doors open, which delays calls from other floors. There would have to be signs at each car explaining to enter the correct one, and signs in each car saying that if you want to travel between floor zones, you need to go via the first floor. Such a configuration would also be much less efficient during off-peak times, offsetting the benefit during busy times, or requiring reconfiguration at many points in time and putting up/taking down the signs.

Instructing attendees would only work during busy times, when all three cars are in use. Otherwise, there would be no way to force the correct car to respond to a call. Because cars would still travel to the other floors to respond to calls on other floors heading down, I think the benefit would be minimal at best. It's hard to know without simulating it or knowing the algorithm that the elevators use.

[JeffT]

Perhaps...it's hard to tell how much it would help or not, but it might help.

The "elevator algorithm" refers to a general class of system (such as flushing a write cache in a hard disk) and when it refers truly to elevators, it only refers to a single car system. As soon as more than one car is added to the system, it complicates things greatly, and you need an algorithm that assigns cars to calls based on a minimization of sum of squares to be truly efficient.

It's true that each car obeys the "elevator algorithm", but consider this: Two cars are in use, the other is idling on the first floor. Person on floor 15 calls the elevator going down. Is the request serviced by one of the cars in use, or by the third unused car? The answer depends not only on the scheduling algorithm, but on traffic analysis--on the likelihood that an additional person will call the elevator afterward, and on what floor they will call it from. That's why it is so complex.

If the system uses a destination floor call system, then cars don't even obey the "elevator algorithm" anymore, and are not limited to servicing requests only in one direction. For example:

Two people on the first floor have called for floors 10 and 15, and the computer assigns them to the same elevator. The elevator arrives and takes them off. On floor 10, another person calls for floor 1. It makes sense for that person to enter the elevator at the first stop on floor 10 to let out the person on floor 10; this avoids it having to stop on floor 10 a second time while going down, even though the person going from floor 10 to floor 1 has to make a stopover at floor 15. With a simple up/down selector, this optimization is not possible.

Second example:

Imagine a 100-floor building, and the middle of the night where there is hardly any traffic. There is a single car available. A person on floor 2 calls the elevator to go to floor 100. Just as the doors are closing after the passenger has entered, a person on floor 1 also calls the elevator to go to floor 100. It makes sense for the elevator to start out going down and pick up the floor 1 passenger and take them both to floor 100. But an elevator following the "elevator algorithm" is unable to make this optimization. (Exercise for the reader: Figure out why I had to specify that traffic was very light for this example.)

[Antares]

http://forums.ohayocon.org/viewtopic.php?t=99&sid=e5db7ca06d85dcf21b6e7c78ddafc40f

We just need to get Elevator Squall!!


"...he basically gave up time at the con to make sure people who had further to travel got on the elevator first. He also made sure people with huge props for their costume were able to get on without damaging their stuff."

[MichaelEvans]

Well, one way of making simple systems work in more complex ways can be to limit sub-portions of the system.

So in this case if we have N elevators, all would service the 'event space' floors (1 and 2 IIRC?), but each individual elevator would only accept floors within a destination block ( (Max - Event Floors) / N.count * N.instance + Event Floors to the bottom of the next N's block ).  Thus the elevator would only got to floors 1-2, and a fixed range of floors.   One way of speeding things up slightly would be to lift this restriction going down (Either from inside only, or from the outside).  It would cause slightly more potential elevator stops at the lower floors, but they'd also tend to be more filled during busy times.

I think that is probably a fairly accurate description of "express elevators", at least as I recall seeing ranges and am guessing at how they could work logically.

Ideally you would have signs on EVERY level for every elevator, with proper explanation localized to that level.

[JeffT]

Michael, I see what you are saying about the express elevators.

Those, normally, however, have separate up/down call buttons that aren't linked.

The problem at the Doubletree is, they would have to support unlinking the cars to do this. Are there three separate up/down call buttons, or just one or two? If there aren't three separate ones, it can't be done for sure.

The only other way to do it is to make each elevator, when it is not in use, return to the first floor and idle with the doors open, so that it is possible to explicitly choose which elevator to enter, or, if it is not there, to know to wait by it because it will always return. (I've seen idling with the doors open exist before, in one building, although it wasn't for this purpose.)

Keeping in mind that regardless of what the configuration of the button panels allows, the software must allow it, too. I suspect more sophisticated elevator computer software (which probably comes embedded into a hardware unit) costs just as much as mechanical improvements that we would intuitively think cost more, just because of the high cost of embedded software development, when measured in the form of efficiency improvements per dollar.

[MichaelEvans]

Unfortunately I don't think they'd like homebrew improvements for that either... probably something about safety and standards.

As for the idling idea.  They needn't idle with doors open.  A call to a floor that's on an elevator's whitelist could simply que that floor for all elevators.

[JeffT]

But the floor selection buttons are on the inside of the cars! So having the doors open is the only way you can get to them.

(Sorry if I misled into thinking that the Doubletree had a destination call system. It doesn't; it just has ordinary up/down call buttons. I was just describing the optimal system which is in use in a few places.)

Yeah, safety and standards are why software for this type of embedded system is so expensive. You can't just lay down code like you can if you're making some casual Internet app.

[MichaelEvans]

I don't think I described it well.  There are a few ways of looking at it, so I'll break it out by button-view.

• On any given floor, pressing a button would add that floor to the queue of any elevators who are allowed to go to that floor as part of the primary service.
• Within the elevator, buttons for any floors in the up direction will only be taken from the allow list for that elevator (1-2?) + (Block range of floors)
• Within the elevator, buttons for any floors on the way down will take any at all OR any in the same list.

In this way, it doesn't matter which elevator you want, and this will tend to draw the elevators to gravitate towards the ground floors, which during busy times will help.

During off-peek times this behavior is once again counter-productive (all elevators being called down.)  However it's more productive from a staffing standpoint, since they needn't change it back and customer service going up won't suffer much.

Of course, between 12 and 8am direction won't really matter much anyway...

I wonder what capabilities their elevator software has?