Just for Elevator Mike

10baseT

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• Mar 12, 2006

• #1

I have just had the pleasure of riding the worlds fastest passenger elevator in Taipei , and what an experience !

Of course , you aren't allowed to "fly" this thing yourself , and the pilot plays a clever game of getting her passengers to look at the ceiling where there is a night scene , while this thing accelerates to 1100M/min in about 5 floors . This thing runs an active balance system where dampers move back and forward to counteract the effect of the other lift passing in the shaft , and also a pressurized cabin to prevent popping ears on the way up and down .
Not really relevent , but an incredible bit of engineering .

Probably more interesting are the 4 660 tonne steel dampers that stay still while the building sways 1.5 meters around them in stormy weather .

 

elevmike

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• Mar 12, 2006

• #2

Not really relevent , but an incredible bit of engineering .

You Bet! Hats off to the engineers at Toshiba! Hi rise hi speed elevators are really a different animal. One thing you didn’t mention was composting for rope stretch during accel/decel ramps. These units are akin to building the SR71 back in the 1950s. Everything is new and different. Truly incredible.

 

Peter Nachtwey

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• Mar 12, 2006

• #3

elevmike said:

Not really relevent , but an incredible bit of engineering .

One thing you didn’t mention was composting for rope stretch during accel/decel ramps.

Click to expand...

That is easy as long as the amount of stretch per newton is constant.

 

Gerry

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• Mar 12, 2006

• #4

elevmike said:

One thing you didn’t mention was composting for rope stretch during accel/decel ramps.

Click to expand...

Now all those to whom English is a second language are rummaging through their dictionaries and scratching their heads in utter confusion wondering just what the heck garden waste has to do with ropes on an elevator.

 

Lancie1

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• Mar 12, 2006

• #5

Confused in Seattle

Gerry,

I am pondering that also. Possible meanings I have thought of for composting:

compensating for rope stretch during accel/decel ramps
controlling...
correcting...
computing...
conserving...
comparing....
competing...
composing...
complementing...
complying...
compressing...
considering...
consorting...
contracting...
compromising...
conspiring...

However, maybe in the Elevator World, “composting” is what you do with the elevator when you don’t allow for rope stretching!

 

Last edited: Mar 12, 2006

CroCop

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• Mar 12, 2006

• #6

Composite(ing)

The materiels that you make the elevator rope out of that will strech yet remain strong regardless of the force (mass*Acceleration) put on it.

 

Gerry

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• Mar 12, 2006

• #7

Lancie1 said:

However, maybe in the Elevator World, “composting” is what you do with the elevator when you don’t allow for rope stretching!

Click to expand...

I think that would be 'compacting'.

 

elevmike

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• Mar 12, 2006

• #8

Ha Ha! I spell so bad even MS Word cant fix it...

Peter, the problem is the ropes dont necessarly stretch at a constant due to envirmental conditions and the natural elongation over time. New ropes will stretch considerably in the 1st few weeks, and less over time. As the lays compress the ropes will have less "bounce". So on super fast-super rise units feedback is from an accelerometer on the car, rather then directly from the main driver. Otherwise you'd be riding a yo-yo on the end of a rubber band.

 

Peter Nachtwey

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• Mar 12, 2006

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No big deal and another physics question

Slow changes over time just mean the system must be tuned over time. That still isn't hard. There is plenty of time between motions to adjust its tuning even if there isn't a lot of computing power. Also, one can measure the weight ( mass ) while loading.
It is like controlling a mass on a spring. So what is the big deal?

1100 m/min in 5 floors. How many Gs is that? Anybody? Lets assume 5 meters per floor.

Mike, what is the maximum allowable acceleration rate for elevators?

 

10baseT

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• Mar 12, 2006

• #10

I'll attach some photos a little later , it is truly an amazing piece of engineering . The car is capable of carrying 2600Kg - Now , we now the acceleration , and the time , what is the peak power required if we state that the weight of the car is negligable ?

 

elevmike

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• Mar 12, 2006

• #11

It is like controlling a mass on a spring. So what is the big deal?

Dampining from the other (supporting) end of the spring? Most anything but death can be delt with with enough $$$$... The big deal is with the engineering econimics.

Mike, what is the maximum allowable acceleration rate for elevators?
What do you think you can tolerate? and what would be considered comfortable by most would provide two very differance answers. Generally 3.0ft ps^2. but do to the fact that with most of our applications we're more concerned with ride comfort then zooming people to the 110th floor, I cant really answer your question with out looking it up in the code. Maybe tomarrow..

 

Peter Nachtwey

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• Mar 12, 2006

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3ft/sec^2 is less than .1 G. If 10baseT is correct the elevator is accelerating greater than .6Gs! That would make my legs shorter and definitely stretch the cable. Do you call the cable wire rope like they do in the navy?

A mass on a spring is easy.
http://www.engin.umich.edu/group/ctm/PID/PID.html

If there is another mass and spring attached to the mass, I can still control that too, but it would take much more than a PID.

 

Gerry

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• Mar 13, 2006

• #13

Peter Nachtwey said:

If 10baseT is correct the elevator is accelerating greater than .6Gs! That would make my legs shorter and definitely stretch the cable.

Click to expand...

If it's a linear ramp - infinite jerk?? Not only short legs but most likely a short neck once you reach your floor.

I expect they limit jerk for the sake of passengers' well-being and so probably use an S-curve ramp resulting in even higher peak acceleration.

 

504bloke

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• Mar 13, 2006

• #14

Heres a bit of info i googled on it, looks very impressive

http://www.elevator-world.com/magazine/archive01/0309-003.shtml

along with a picture

http://home.businesswire.com/portal/site/home/index.jsp?epi-content=PUBLIC_IMAGE_VIEW&newsId=20041215005991&newsLang=en&contentItemId=1200954

 

10baseT

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• Mar 13, 2006

• #15

In actually fact the feeling of stomach in boots is very small , I also figure that the trick that the pilot uses of getting you to look at the ceiling at a little planetarium show also helps to reduce the perception of movement . Seriously , I have been on much slower lifts where the acceleration felt more .
Of course , this is only a matter of perception , and I have no doubt use of "S" curves features highly .