The Science Behind Elevators

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Spanning Tree

Spanning Tree

Күн бұрын

What algorithm should an elevator follow to decide which floor to visit next? What if there are multiple elevators? What should the elevators prioritize? In this video, we take a look at some of the algorithms and priorities that elevator systems might take into account.
0:00 The Elevator
2:09 Multiple Elevators
3:24 A Modern Approach
Interested in reading more about the science of elevators? Check out this Popular Mechanics article, which served as one of the inspirations for this video.
www.popularmechanics.com/tech...
***
Spanning Tree is an educational video series about computer science and mathematics. See more at spanningtree.me
To be notified when a new video is released, sign up for the Spanning Tree mailing list at spanningtree.substack.com/
Spanning Tree is created by Brian Yu. brianyu.me/
Email me at brian@spanningtree.me to suggest a future topic.

Пікірлер: 305
@ripwallet3318
@ripwallet3318 3 жыл бұрын
I clicked on the video without looking at the channel name or views. The quality of the video was so good that I thought it must've had millions of views. Amazing job!
@puneetchhabra411
@puneetchhabra411 2 жыл бұрын
Really!! Commendable 👍👍
@Dhruv12x
@Dhruv12x Жыл бұрын
the effort put it in deserves credit !
@eggs761
@eggs761 Жыл бұрын
Oh my sorry there was a giant monkey outside
@firelordkevin2768
@firelordkevin2768 Жыл бұрын
Good vid but get a new mic and record with sound damping
@TheBrawlmastah
@TheBrawlmastah Жыл бұрын
Except the sound quality is shit
@pitchblack5422
@pitchblack5422 Жыл бұрын
Crazy how many little design decisions we overlook every day, I have used elevators for almost all my life but ive never once thought to think that their might be more behind the scenes to improve our experience
@Kris4Infinity
@Kris4Infinity Жыл бұрын
Only shows how many things we all overlook everyday- and how we take some things for granted heh-
@pitchblack5422
@pitchblack5422 Жыл бұрын
@@Kris4Infinity for sure
@rishabhanand5563
@rishabhanand5563 Жыл бұрын
Most of us don't even realise how much its going on inside our body unless you are a doctor😂
@xninja2369
@xninja2369 Жыл бұрын
@@rishabhanand5563 that was a good one
@Starkl3t
@Starkl3t Жыл бұрын
I've thought about it since I was a kid lol. Some of us are curious I guess.
@chronxdev
@chronxdev Жыл бұрын
I've actually coded up an elevator algorithm before, and it was a huge pain in the ass. The calling algorithm is definitely one of those non-trivial things that no one ever really stops to think about or appreciate
@hariranormal5584
@hariranormal5584 Жыл бұрын
I tried implementing it in a game using basic logic gates, following a circuitry which was used by lifts back in the 60's.
@VermaAman
@VermaAman Жыл бұрын
Oh I've thought about it a lot whenever I wait for an elevator in my office, I wonder what's the algorithm behind it. It fascinates me that how they work.
@the_CreativeGenius
@the_CreativeGenius Жыл бұрын
Can u predict algorithm behavior based on reinforcement learning? Kindly?
@pianissimo7121
@pianissimo7121 Жыл бұрын
I am a beginner programmer and thought about this problem. Understood it was way beyond my level and gave up.
@d5kenn
@d5kenn Жыл бұрын
For some odd reason, I've devoted an unreasonable amount of passive headspace to what it would take to write a complete elevator algorithm, including how to handle people pressing floors while it's moving, and accounting for private floors. So I was tickled to see this explanation. Thanks!
@d5kenn
@d5kenn Жыл бұрын
@@tylisirn omg. Thank you. This hol...I mean game, was made for me.
@liriani
@liriani Жыл бұрын
@@tylisirn wow this is very interesting
@eennou
@eennou Жыл бұрын
@@tylisirn Thanks man, that’s fun!
@colinwood9717
@colinwood9717 Жыл бұрын
When I was a teenager first learning how to program (in actionscript!), I once had the idea to code up an elevator algorithm. I glad I never got around to it, because it seems way too complicated for 13 year old me 😂
@pieter5466
@pieter5466 Жыл бұрын
@@tylisirn I KNEW THIS HAD TO EXIST (or I might have made it). The Internet has delivered again in the form of yt commentsssss
@AdrianHereToHelp
@AdrianHereToHelp Жыл бұрын
I have always thought that elevators have one of the most insane design features, in that they ask you whether you want to go up or down It sounds obvious, but that's the kind of stuff every programmer *wishes* they could add, just stopping the user and saying "hey, so how do you actually want this to work?", and elevators just did it and it became standard and no one questions it now. Incredible
@zbowmasteri
@zbowmasteri Жыл бұрын
but I have the feeling many people even dont get this and push whatever button or both, to make the elevator appear faster :D
@retrogiftsuk4812
@retrogiftsuk4812 Жыл бұрын
Those elevators look dangerous. Stand in the wrong place on a floor and an elevator could pass through the ceiling and flatten you! Joking aside, this is a great video. Loving the channel. 😀
@affyne
@affyne Жыл бұрын
heres your fear coming true TRIGGER WARNING! kzbin.info/www/bejne/bajHgZqQdrdoosk
@shiroyasha_007
@shiroyasha_007 Жыл бұрын
😀
@iameverywhere8551
@iameverywhere8551 Жыл бұрын
😀
@xninja2369
@xninja2369 Жыл бұрын
I thought same
@ersetzbar.
@ersetzbar. Жыл бұрын
One needs to optimize an algorithm for max wait time. How long can you stretch wait times, how slow can you make it move , so that a maximum of 10% od people use the stairs
@erayk96
@erayk96 Жыл бұрын
I stayed in a hotel in Sunny Beach - Bulgaria a couple years ago. There was only one elevator and it was SO slow, the first time I got on it, I wanted to leave before we reached the first floor. It was a shock, nobody expects an elevator to be that slow. At first we thought it was faulty, but it wasn't. We started laughing at the absurd slowness of the elevator. Only used it a couple of times going up, never when going down :D I could easily walk upstairs at the same speed as the elevator, and if I hurried just a little bit, I was faster than it.
@ersetzbar.
@ersetzbar. Жыл бұрын
@@erayk96 opposite of my previous work there was one similarly slow. it even had the feature that when you pressed 6 it also triggered 4. the people who worked in the top floor "loved" it
@2fortsmostwanted
@2fortsmostwanted Жыл бұрын
Nothing gets your heart rate up like an elevator that’s not working properly, whether you get on it or take the stairs.
@ersetzbar.
@ersetzbar. Жыл бұрын
@@2fortsmostwanted poetic
@gary6364
@gary6364 Жыл бұрын
An elevator that goes back and forth between floors, intentionally avoiding everyone’s destination, and keeps picking up confused passengers would do the job
@quinton1661
@quinton1661 Жыл бұрын
One really neat system I've seen is to select your destination floor before you get into the elevator car. A screen tells you which elevator to enter and takes you to the floor. At first, this system had no buttons inside the elevator, but they eventually retrofitted them probably because it's confusing for anyone not used to it. This system allowed the computer to more effectively schedule the cars.
@nelsonahlvik6650
@nelsonahlvik6650 Жыл бұрын
It's called Destination Dispatch
@DieNetzente
@DieNetzente Жыл бұрын
Never seen it, but it was exactly my thought. Algorithm could be improved if the elevator would know the destination before arriving on a floor. However, people are already confused by the two buttons (up and down) as they tend to press both of them, hoping the elevator would arrive faster
@galpratama
@galpratama Жыл бұрын
I’ve been used this kind of elevator in certain hotels, and boy it was confusing as first, but so effective
@EoRdE6
@EoRdE6 Жыл бұрын
The elevator in the building I used to live in had you input your destination on a screen which would assign you an elevator and call it, it could then group passengers for the same floor together, or the same range of floors, and it knew how many passengers were assigned to each elevator and when it was at capacity. Very clever system.
@MST339
@MST339 Жыл бұрын
Every passenger has to punch in his floor at the lobby, and watch for elevator assignment. Everyone, yes. And one must go down to the lobby, reach the console, do the same, in order to go to another floor.
@Anson_AKB
@Anson_AKB Жыл бұрын
i recently encountered such a system in a hospital with something like 15+ floors and 10+ elevators. each(!) floor had a panel where everybody(!) needed to select his destination, then got an elevator assigned on a screen display by elevator number with a little diagram where that is. after entering that elevator, you wouldn't have to select the floor again (there even were no buttons besides overwrites for stop/emergencycall and the doors), and you magically would quickly (with no interference by "button pushers", and mostly together with only few other people/transports that had the same source and destination) be brought to the correct destination.
@erayk96
@erayk96 Жыл бұрын
Let's say you had friends over, and all 3 of you leave your apartment for drinks at a bar. What happens then? Do you input how many people are waiting for the same destination, or does each person have to input the same destination again and again? Or is it just simply it cannot correctly know how many passengers are assigned to that elevator in that case?
@EoRdE6
@EoRdE6 Жыл бұрын
@@erayk96 there are multiple screens on each floor and it takes about 1 second to enter the destination so you either A. Hit floor 1 three times or B. Hit it once and hope the elevator doesn't get overcrowded
@erayk96
@erayk96 Жыл бұрын
@@EoRdE6 Well, that makes sense. For some reason I thought the input process would be longer than a regular elevator :D Thanks!
@misterfunnybones
@misterfunnybones Жыл бұрын
There used to be a 4 storey building at 1014 Homer St in Vancouver that had a slow elevator that went to the floors in the order they were selected, so if you wanted floor 4 & the riders entering selected 3, then 2 & then you press 4, it went literally 3, 2, 4. So savvy riders would block newbies from pressing anything until a discussion of floor preferences was completed, then floors would be selected for greater efficiency. Needless to say, the stairs were well used.
@kigood
@kigood 2 жыл бұрын
This video is incredible! The explanations were clear and concise and the animation was simple and helpful. Bravo!
@MackAttack101
@MackAttack101 Жыл бұрын
man i've been thinking about this for a while, how elevators decide on what floor to go to. it's super cool to find a video that explains it so well.
@PedroContipelli2
@PedroContipelli2 2 жыл бұрын
Amazing content on interesting subjects that I don't see anyone else covering. Great job!
@seandreihere
@seandreihere Жыл бұрын
I love how this made me interested in learning the algorithm behind the elevator.
@prosamis
@prosamis Жыл бұрын
Lovely video! Way higher quality than I expected clicking onto it
@parantbellum
@parantbellum Жыл бұрын
Fascinating. I never had to face the elevator problem, but more than a decade ago I started writing systems who are able to learn and adapt their behavior; it's funny how 2 days in they are still "stupid" and predictable, but how their decisions puzzle me after just a month. Or how two identical systems behave differently depending upon the environment they are placed in. Thanks for this video, you've got yourself a new subscriber :)
@shashankhegde4007
@shashankhegde4007 Жыл бұрын
I don’t know how this channel does not have more views, such a great content. Please don’t stop. Keep doing your great work
@dreamcatcher9712
@dreamcatcher9712 3 жыл бұрын
Awesome explanation, informative and helpful 👍 Do more videos on algorithms
@julienbourgouint9671
@julienbourgouint9671 Жыл бұрын
I was asking myself this question for a long time and I love this video handled it. key points : In the single lift case - going to the nearest waiting person may mean a far user has to wait for ever - not a viable solution. - there is a solution that eventually serves every user (all the way up then down then again). - that solution can be slightly improve by not going all the way if there is no one waiting. In the multiple lifts case - it's dump if 2 lifts just follow each others. Hence lifts should specialise. - the best algo depends on the building characteristic and what we are trying to minimise. - the best algos can be find with reinforcement learning.
@Samuel-gw1hz
@Samuel-gw1hz 4 жыл бұрын
Great quality, I appreciate a lot !!
@punditgi
@punditgi Жыл бұрын
Amazing channel with a truly gifted creator! Bravo, monsieur! ❤🎉😊
@veebatechworld530
@veebatechworld530 Жыл бұрын
Looks simple, it gave overview of design and working model . Thanks to you.
@Hieucd97
@Hieucd97 2 жыл бұрын
Great video! I was just thinking about this problem while waiting for an elevator
@MdARahim
@MdARahim 3 жыл бұрын
Great Video! cute animation, nice explanation! Thanks for the video.
@wictimovgovonca320
@wictimovgovonca320 Жыл бұрын
Just to throw another wrinkle into the algorithm, check out double-deck elevators. They service two adjacent floors at the same time. The reason is to reduce the floor space for elevator shafts as you can service (in theory) twice as many people using the same elevators. At the start of the day you go to the basement of the building if your destination is an even-numbered floor, and to the ground floor if your destination is an odd-numbered floor. If you are in the even level, and someone in the odd level pressed floor 7 but nobody requested floor 6 then the elevator would stop to service the other level but your doors would remain closed - a bit disconcerting the first time you take it. They do support exceptions like someone wanting to travel from floor 5 to floor 8, but if you enter from the ground level you cannot press floor 8.
@matth8617
@matth8617 Жыл бұрын
Very interesting that this got recommended to me. Since august, I’ve been living in a dorm at college. My dorm has 2 elevators in it and since I’ve never used an elevator this often, I started to think about it. For the last semester and a half, I’ve been thinking about this “elevator algorithm” and KZbin just seemed to read my mind lol
@heyheybobbyj
@heyheybobbyj Жыл бұрын
A great day is when a video pops up on my recommended that teaches me something I never thought about before. Great video
@MrDanielmahaniel
@MrDanielmahaniel Жыл бұрын
This is so cool and something I would’ve never even thought about. Thanks!
@eponymouscharacter
@eponymouscharacter Жыл бұрын
Great video. I was thinking about this yesterday. Didn’t say anything to anyone about it, didn’t search anything on my phone or laptop. Just wondering in my head. And then this popped up in my feed the next day. Crazy.
@Daiyuki117
@Daiyuki117 Жыл бұрын
This video unlocked childhood memories of some game that looked a lot like the presentation, and you have to think about the elevator systems like this to ever have an efficient building.
@entitxy_4810
@entitxy_4810 Жыл бұрын
Great vid, one solution i have to minimize most wait times is a timed system where a floor's importance to be served is exponentially calculated (for example timeWaited^1.5), where the elevator usually goes to near floors first (by multiplying nearby floor's importance by a higher number the closer it is, like current*3, off by one*2.5, etc), but eventually far floors would get higher priority. Nonetheless this is a problem that has no single truly correct solution, a lot is based on context (an optimal hospital elevator needs to prioritize based on the patient's condition, probably including an elevator stationed on the intake floor to provide critical patients service as quick as possible; an optimal buisness elevator might prioritze based on approximate rank of the person badging into the system, wasting as little of the CEO's time as possible but letting managers and employees wait a little) - however, these require more logic/devices integrated into the circuit (for the hospital a nurse has to badge in and rank their patient's criticality 1-10, for example)
@Non-disjunction
@Non-disjunction Жыл бұрын
Amazing video, thank you
@Jarturoac
@Jarturoac Жыл бұрын
This problem sounds a lot like an scheduler from an operative system having to choose which process gets the CPU and when. In this sense I think that that the "Highest response ratio next" algorithm (HRRN) might be a good attempt at solving the problem
@d19sbp
@d19sbp Жыл бұрын
I was in a hotel once where you had to pres the "going up" button even when going down, if you pressed the "going down" button you would end up with an overcrowded elevator every time
@yelissasue
@yelissasue Жыл бұрын
Wow! I am feeling weirdly proud of myself for realizing it was Brian talking just one minute in! How nice it is that we meet again in a random video dear sir! Nice channel! Lots of love from edx cs!
@pabloguzman583
@pabloguzman583 2 жыл бұрын
A trully wonderfull video, i wish ir had better audio cuality
@shufflecat3334
@shufflecat3334 Жыл бұрын
How would I manage elevators? I would maximize travel speed as much as possible. You would enter on the ground floor, and after a brief pause, you would be slammed into the ground as the elevator begins accelerating upwards at 2.5 Gees. Then, after the elevator overshoots the requested floor, it would accelerate downwards slightly faster than 1 Gee, meaning that you would be in free fall for a second or two. Once the destination has been reached, the doors will remain open for exactly 400 milliseconds to give you a chance to exit. After the doors close, the elevator would briefly visit the basement for cleaning before returning to the ground floor to pick up more passengers.
@debadityanath4398
@debadityanath4398 Жыл бұрын
perfect approach, if i ever make building with elevators, i will use this
@toddkes5890
@toddkes5890 Жыл бұрын
Sounds like the elevator from "Who framed Roger Rabbit"
@hariranormal5584
@hariranormal5584 Жыл бұрын
Jokes aside, the actual driving of the elevator is important for time saving. Bigger lifts actually now use fast accelerating motors, and very quick de accelerations. But it comes at a cost! As reliability should not be compromised, but still need greater efficiency. So the approach on how the elevator knows when to slow down, when to fully apply the breaks, when to open doors, all when keeping in mind other safetys is a bit complicated. But it can be done. And seeing those machines do their job fast is beautiful. Search for the video "Awesome Efficient Kone M series" by Beno
@mehrdadmohajer3847
@mehrdadmohajer3847 Жыл бұрын
Thx. Early 80's got group assignment ( whole class in Computer Science ) to come up with such a Algorithem . I couldn´t do well, finding it difficult to make flow chart fulfilling our aim. I learned however to Appreciate This and other ROBATICs as such, made by Human ingenuity, hard work & endurance on their way to " Goal-Achievements ".Cheers🍻
@carnage_10
@carnage_10 Жыл бұрын
thank you for the video
@laurenlin2
@laurenlin2 3 жыл бұрын
A fun and interesting video!
@zachytacky5465
@zachytacky5465 4 жыл бұрын
and yet they still cant figure out how to put some good music in them
@amandadangerfieldpiano
@amandadangerfieldpiano 2 жыл бұрын
Hahaha!
@sagittarius5466
@sagittarius5466 Жыл бұрын
This was surprisingly interesting
@trygvehalsbutenschn1125
@trygvehalsbutenschn1125 Жыл бұрын
Great video!
@QDLee01
@QDLee01 Жыл бұрын
Please make more videos these are great
@lkekama
@lkekama Жыл бұрын
Great video. One thing I'd add to elevators if I could, would be to enable them to display the amount of wait time to passengers waiting for one.
@WilburJaywright
@WilburJaywright Жыл бұрын
TYJ, I’ve had this question for years!
@ryanford9310
@ryanford9310 2 жыл бұрын
Fantastic video your doing well for your sub count
@PLNCPedroLucas
@PLNCPedroLucas Жыл бұрын
Now image all that (except the neural network stuff) with relays... Oh wait, it's how they used to be! Since the 1910's! And in the 1950's with vacuum tubes (and later with discrete transistors) they also managed to account for the cab load / time inside cab factor. Awesome machines. Fascinating to watch it working. It's noisy too haha
@justinmayhew6848
@justinmayhew6848 Жыл бұрын
I assumed elevator algorithms would be simple clicking into the video, but oh was I wrong! Great video, who would have thought there would be so much complexity in something seemingly mundane
@Tarou9000
@Tarou9000 Жыл бұрын
Wow, kinda glad this showed up in my feed while working on an elevator for a mall. As a programer programing a virtual environment resources aren't something to care about so you can simply put more of what i call "elevator complex" with a simple algorithm that just takes one person and simply taking them to their desired spot. The machine learning system sound very interesting but i feel that's too complex for my level.
@monzerfaisal3673
@monzerfaisal3673 Жыл бұрын
I am a delivery driver that goes to 60+ buildings per day. Have tried many different elevators so naturally I've started to wonder about just this. Great video!
@sarthakjain1824
@sarthakjain1824 Жыл бұрын
That was perfect video
@anjourney99
@anjourney99 Жыл бұрын
The ideas behind the video are interesting, as we should think about how we optimize daily tasks, rather adding more sub-tasks
@vadiks20032
@vadiks20032 Жыл бұрын
it's fascinating how some simple things actually take a lot of effort and time to actually implement properly
@petersaundersuk
@petersaundersuk Жыл бұрын
I used to live in a 21 storey apartment block with two lifts. Both lists serviced the ground floor, 1st floor and 21st floor (it's in London so the 1st floor is up 1 level from the ground). Lift 1 serviced all the remaining odd numbered floors and lift 2 the even numbered floors. From any level above the ground floor you could only call a lift to go down so if you wanted to go from the 3rd floor to the 6th floor you would have to go to the ground level first unless you are lucky enough that somebody was already going up and the lift happened to stop on your floor. If a lift hadn't been used for a while, it would go to the 10th or 11th floor to wait for the next resident calling it. While this seems a really strange way to work, it was actually quite efficient and when the lift engineers changed the programming, people generally had to wait longer for the lift to reach them. I could never quite work out why this was 🤔
@MaskedDeath_
@MaskedDeath_ Жыл бұрын
"How would you manage an elevator sytem?" Me, an engineering student studying automation: *panicked noises*
@anantmalik
@anantmalik Жыл бұрын
Thank you to all the engineers who create such self learning machines, algorithms etc. Unknown people who we never know about. O.O
@rhettorical
@rhettorical Жыл бұрын
Worth noting that one reason for the complexity is that users can input requests at random. A more efficient system from the elevator's perspective, but less convenient from the users' perspective, would be to have everyone input their requests to be serviced at once, so the elevator(s) can decide optimal routing before they ever start moving. I run into issues like this at my job quite frequently. I might design something to be optimal from my point of view, only to have end users, testers, or designers come to me with a request to design things from a different perspective. It's inconvenient for me, but creates interesting challenges for making things more user-friendly.
@shimaalcarrim7949
@shimaalcarrim7949 Жыл бұрын
This channel is 💥
@justingolden21
@justingolden21 Жыл бұрын
I kept thinking about this and discussed with my friend and he kept giving overly simple answers, but I kept asking deeper questions, like when he said "a queue" I said does each elevator have one, is there one global queue, what happens when there are more people waiting than elevators, can you avoid starvation, what is "optimal", speed, time in elevator, average wait time, mean or median wait time, longest wait time, etc.
@lewisjones284
@lewisjones284 Жыл бұрын
That moment when you are given an assignment and KZbin provides you the solution immediately
@galbutler
@galbutler Жыл бұрын
this channel is so underated wtf
@DataUser1357421En
@DataUser1357421En Жыл бұрын
How about keeping track of all the variables such as waiting time and energy usage, and create a function to convert the current planned route (with all the nuances like speeding up and slowing down) to relevant variables (a prediction of waiting times), then create a score that optimize whatever variable you want to optimize, then constantly re-calculating estimated score based on the sequence of planned stops and updated variables, and adjusting the planned stops in real time, as much as is physically possible? Or maybe that is what they are already doing?
@Jason9637
@Jason9637 Жыл бұрын
That is exactly how it works. The AI decides the path, and the humans give it a score based on whatever they are trying to optimize. The AI will then learn to optimize for the best score.
@brenda0006
@brenda0006 Жыл бұрын
During covid, my local hospital only allowed 4 people on an elevator at a time. This didn't really impact me that much since I usually just travelled between G and 2 for my infusions so I'd just take thr stairs. But if I have a specialist appt I have to go up to level 9, so when I got sick of waiting one busy afternoon, I decided to take the stairs since 2 floors wasn't too bad... well after the 4th or 5th floor I regretted it and felt bad for being unfit... until I found out a week later that I was having a flareup 😅 so I don't mind waiting now haha.
@hotlinefrenzy
@hotlinefrenzy Жыл бұрын
That frustration when I get to wait for the elevator on 4th floor and it completely ignores my request, heading up and down on below floors, just to eventually switch direction and pass through to the 7th and finally down again. Now I know exactly why it happens 😅
@revelmonger
@revelmonger Жыл бұрын
I was literally thinking about how this could be solved with a priority queue when you mentioned the similarity.
@RaselKhan-gd1of
@RaselKhan-gd1of Жыл бұрын
Impressive
@pieter5466
@pieter5466 Жыл бұрын
One interesting aspect of these algorithms and whichever performance metric chosen, is the (presumably declining) marginal return as more optimizations are added.
@zardinus1
@zardinus1 Жыл бұрын
this is cool.
@thenamen935
@thenamen935 Жыл бұрын
At my university they have installed very intelligent elevators. So the building has a total of 15 floors and about 12'000 students every day. So this building has got 4 sets of 3 elevators each. If you get to the elevator instead of pressing "up" or "down" you actually chose which floor you want to get to. Now a screen instantly tells you which of the three elevators you should take. The computer consideres how many people are waiting, how many people want to get from which floor to which, which elevator is nearby, how many people are in the elevator and so on. You rarely have to wait longer than 2minutes for an elevator and aren't in it longer than a minute or so. And I think that is pretty impressing considering the size of the building (one floor is as high as 2-3 floors in a normal house) and the amount of students who have to use it at the same time (everyone changes rooms within the same short time period).
@nidodson
@nidodson Жыл бұрын
I always wondered why there aren't buttons on each floor for what floor you want. Then it highlighting which floor requests go to which shaft, which seems like it would be more optimal.
@iidentifyMyselfAfemalepotato
@iidentifyMyselfAfemalepotato Жыл бұрын
Great
@ericgolightly8450
@ericgolightly8450 Жыл бұрын
I love learning about elevators
@670839245
@670839245 Жыл бұрын
My late grandma's home was in a 24-floor building. There are two elevators next to each other, and when no one calls an elevator, it tends to keep one at 1F and the other at 12F. When we call the elevator from 16F, this somehow often happens: - The 1F elevator moves first. IDK why, but my guess is a bug makes the 12F elevator open its door before it goes up, and elevator recognizes that the 12F elevator is now unavailable due to the open door, thus moving the 1F elevator up. - The 12F elevator finally closes its door on its own - at this point, the other elevator is at 8F - With both elevators finally both available and the 12F one being closer, the 12F one now starts moving up towards 16F, and the other one just awkwardly makes a stop at 8F.
@rakdance
@rakdance Жыл бұрын
In many buildings, there is now a new technique being employed for elevators, where the passenger waiting doesn't just press the button for up or down, but, inputs their destination floor. Now the elevators not only know where there are waiting passengers, but, also where they intend to go. The elevator bank then tells the passenger which elevator car is coming for their destination, and when the door opens, it displays all the floors that that car is going to. Every time I get to a building with this system, I'm wondering how the elevators are optimized.
@paulban889
@paulban889 Жыл бұрын
An interesting idea would be for the passenger to input the floor they are going to at the point they are summoning the elevator from. This way the computer would know the desired destination of those wishing to use it before sending the elevator. This might result in a more optimal route calculation.
@Mark00747
@Mark00747 Жыл бұрын
"The Science Behind Elevator Algorithms" seems more appropriate, since there is a lot more to elevator science. (Think about mechanics for example.)
@kityew23
@kityew23 Жыл бұрын
One logic that should definitely be implemented into elevator algorithm is the carrying weight. If an elevator full of passengers is approaching its max capacity, then it should stop stopping at every floor attempting to pick up more passengers, especially when assuming most people are likely headed for the lobby / a popular floor.
@emperorsascharoni9577
@emperorsascharoni9577 Жыл бұрын
Would just say move to earliest press of the button after last passenger gets off then after collecting this passenger collect any people moving in same direction. If earliest press is top or bottom floor also take and deliver people on the way to them. Any passenger pressing opposite direction of current travel (would only get in if pressing wrong call button) will be delivered last, also taking people who go the same direction with. This would be somewhat of a tradeoff between wait time and Efficiency.
@rishi_rajani
@rishi_rajani Жыл бұрын
I believe Image Processing is a much needed feature too
@RilianSharp
@RilianSharp Жыл бұрын
there was one bank of elevators i encountered where it seemed like pressing the button a bunch of times in a row made a previously dormant elevator wake up and come get us. but idk, i didn't have time to experiment or find the people who designed it.
@Gideonrex1
@Gideonrex1 Жыл бұрын
I was thinking to optimize on the summation of squared wait times so that individuals waiting longer have a larger influence
@Gideonrex1
@Gideonrex1 Жыл бұрын
@@gregoryford2532 why would minimizing the summation of squared wait times maximize wait times. Doesn’t make sense.
@yash1152
@yash1152 4 ай бұрын
0:47 woww, so, these are the (umh, can't recall the name..) disk lookup/servicing algorithms from "operating system" right? the scan, c-scan, look, c-look, FIFO, ... (oh god, i don't even remember names of the algos 😓) and problem mentioned is formally called "starvation". awesome. interesting. intriguing. and these visuals are making me want to try implementing these algos in scratch language as i want to visually live these algorithms.
@yash1152
@yash1152 4 ай бұрын
1:43 yeah, here :)
@yash1152
@yash1152 4 ай бұрын
3:36 > _"can try one scheduling algorithm"_ yeahh, got it. "disk scheduling algo" - but yeah, just "scheduling algo" seems better/more general term
@siyustuff213
@siyustuff213 Жыл бұрын
damn ive never actually thought about how the elevators in my apartment decide which floors to visit well in my case its rather simple as its mostly just transport between ground and apartment but still very interesting
@Check_001
@Check_001 Жыл бұрын
What are these elevators? I guess they are mostly for business buildings and such, where people actually have a need for travelling up. In most of our houses we have just one button, supposedly because it rarely has sense for anyone to go to the upper floors, it's just to go to the first one
@zoronic6248
@zoronic6248 Жыл бұрын
I swear to GOD you did videos for Harvard's CS50 edX course. Good work btw
@zoronic6248
@zoronic6248 Жыл бұрын
Ah, I was right. Followed the link in your bio. The satisfaction is strong in this one.
@gauravkhaire56
@gauravkhaire56 Жыл бұрын
I heard his sound and was like "The CS50 guy?" and then I clicked on channel , read brian yu and immediately subbed🎉
11 ай бұрын
These elevators should have weight measure systems too, like, if the weight of the elevator is at 80% or above the limit, it should skip requests of other floors. And in public place like hospitals where a lot of people do not know well how the elevator function, the go down/up should be made clear so that people won't accidentally go in wrong direction elevators.
@Labib_1453
@Labib_1453 8 ай бұрын
what about automata theory.. which fsa can describe how it works/shceduled 🤔
@macprofire
@macprofire Жыл бұрын
Does optimizing for minimal waiting time really leave people stuck? Eternal waiting doesn‘t seem that minimal to me. Maybe the described approach was wrong, but the goal is still valid
@craigleverenz
@craigleverenz Жыл бұрын
There's a shopping mall in my city which has about 10 floors. All the elevators are glass and have a sign by the button that reads "elevators may skip floors to prioritise those with the longest wait times". The stupid thing about this algorithm is, every floor ends up waiting the longest possible time for the elevator to come and pick them up.
@DavidMcCoul
@DavidMcCoul Жыл бұрын
They’re talking about A.I. and machine learning at the end!
@JuchePasa
@JuchePasa Жыл бұрын
What about Paternoster lifts?
@howtolagmuch8706
@howtolagmuch8706 Жыл бұрын
Man, I could watch those little guys use the elevators for hours and not get bored
@gameclipz9890
@gameclipz9890 Жыл бұрын
respect for algorithms is incresed however i feel that sectional partitions mau cause more efficiency isent it!
@Cyberfoxxy
@Cyberfoxxy Жыл бұрын
Always thought elevators was an interesting subject. Mostly because it a problem. And when I wait for an elevator. I start thinking of solutions. If you have one elevator. Of course you need to use the base algorithm. But I think it would be effective when idle to have it move to the first floor. When you have multiple elevators things are getting interesting. One could always wait in the middle. I there's also "abuse". I found that it takes roughly the same time to open and close the door and the time of takes to travel all the way to the bottom. In my building we had a company that spanned 2 floors and they were frequently clogging up the flow because they couldn't be bothered to take the stairs one floor. That adds 2 stops and a 10 second travel time is now about 40 seconds. Such floors could be assigned a lower priority making them only serviced on every second run. Unfortunately more and more elevators don't show it's number while you're waiting. So you can't glean anything other than it sucks.
@Henrix1998
@Henrix1998 Жыл бұрын
I think an Elevator Simulator game, like a traffic simulator, could be great fun for a while
@hariranormal5584
@hariranormal5584 Жыл бұрын
There are definitely some, but depends on your purpose. Skyscrapersim is a dead project
@Victor_Gvne
@Victor_Gvne Жыл бұрын
In my building you have to indicate on a screen which stairs you are going before entering the elevator, and then the screen tell you to take a particular elevator, for exemple the C one among 8 of them. It can be a next video 🤷
@zxuiji
@zxuiji Жыл бұрын
There's still a faster way for the elevators to operate, queue the calls with timestamps and go to the first in the queue, picking up any others that were queue'd along the way, whatever direction it had to go to get to the 1st in queue it will then prioritise that direction before going to the next in queue, dropping off any that needed to go further down that direction along the way
@7iceman
@7iceman Жыл бұрын
Where can i change this algorithm for my University elevator?
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