Living in the 21st century is learning about an unsolvable problem, waiting two weeks, then stumbling across people who solved it

@lil-j-waters

15 күн бұрын

well said

@ronfitzhenry3726

13 күн бұрын

So true

@adolfsnape1481

11 күн бұрын

it's unsolvable by hand, but you can simulate it using a computer.

This truly is the world's first video of 56 transition controls for a triple inverted pendulum.

@noahtekulve2684

Жыл бұрын

And also one of the videos ever!

@Vini-BR

Жыл бұрын

HAHAHAHAHAHAHA 😆

@ragnarocks9121

Жыл бұрын

This video numbers among the other videos on youtube

@AnonyMous-pi9zm

Жыл бұрын

Before seeing this video, I had never seen this video!

@brickbooms

Жыл бұрын

This is definitely a video of all time

From description: “The sampling time is 1 ms” Wow, that’s not nearly as fine as I would have expected for a 3 pendulum control system, and yet it doesn’t seem to have any trouble at all.

@JavierSalcedoC

8 күн бұрын

yeah thought the same, probably the friction of the parts is high enough for the algorithms to work. In my ignorance I´d say that doing this with friction zero could be impossible?

@bolt7

Күн бұрын

@@JavierSalcedoC Zero friction makes it impossible to statically balance (without constant adjustments), but given the point is to dynamically balance them (actively move around) there's no reason it would be impossible.

6:55 that 5-3 was poetry

@harriehausenman8623

Жыл бұрын

One of my favs too!

@nsv8613

9 күн бұрын

The 6-3 is also so mesmerizing 7:15

@HDL_CinC_Dragon

Күн бұрын

I laughed out loud with that one. Just incredible how effortless it looks.

Honestly, I would have been skeptical that this would even be possible. Just…wow.

@lostmykeys85

Жыл бұрын

The mathematics involved are being done … so fast …

@DSAK55

Жыл бұрын

I can do one of them

@niquel5831

Жыл бұрын

@@DSAK55 I can do 7 of them.

@mezaomar

Жыл бұрын

@@lostmykeys85 Well it says "1ms"

@GeorgeSmileyOBE

Жыл бұрын

Congratulations.

I feel like this is the engineer's version of the sorting algorithm video

It can't be reasoned with. It can't be bargained with. It doesn't feel pain. And it absolutely will not stop until momentum is dead.

The fact that it can go from position 1 to any is already impressive as hell. Then it can go from ANY position to ANY other without returning to any other intermediate position is crazy to me. And from unstable positions to other unstable positions. Sooooooo freaking Impressive.

@someonesomewhere1240

Жыл бұрын

At 5:46, 8:15 it's maybe being a little bit cheeky on this front, but still... damn impressive.

@markdunlop4

Жыл бұрын

Not taking anything away from how awesome this is but 2 to 6 and back goes through 5

@michaelanderson7924

Жыл бұрын

Just a pedantic note: these positions are technically “marginally stable” But this in no way makes it any less impressive!

@DaftFader

Жыл бұрын

@@someonesomewhere1240 I think it's impossible to swing all three outstretched from bottom full extension to top full extension without it crossing another equilibrium position due to inertia. If they just full send it fully extended the entire swing, they'd be unable to correct without the thing collapsing back down, and wouldn't be able to stop it dead upright like that, this is probably the only way to do it (or shortest path at least). There are a few movements that fall to similar restraints, and some transitions are just going to have to pass through other equilibrium points. As long as they aren't fully stopping there I think it's unavoidable.

@TomBertalan

Жыл бұрын

​@@michaelanderson7924 why, because of the cart DoF? I think you can disregard that.

I never thought that triple pendulum could be controlled. This video definitely needs more attention!!!

@RuLeZ1988

Жыл бұрын

This is really impressive. I believe each axis has different weights, and also the distance between the axis of the connection in the very background is shorter than the other connections. This Setup with these different weights play probably a very important role to make these transitions possible. I wonder if these transitions would be still possible, if the weight on each axis would be the exact same or if it then would be near to impossible to control the pendulum like that.

@Alucard-gt1zf

Жыл бұрын

Of course it's possible, that's the whole point of chaos theory

@stevekim9662

Жыл бұрын

​@@Alucard-gt1zf Yes but it's impressive cause although it is theoretically possible, it is close to impossible in reality.

@bigmike-

Жыл бұрын

In theory, it's possible to control an arbitrary number of pendulums - it's just that the difficulty goes up significantly with each additional pendulum added to the system.

@DaftFader

Жыл бұрын

@@bigmike- Yeah the margin for error goes down "exponentially" the more you add.

In my last school year, 2018, my .ath teacher told us, if we could figure out how to predict/control a triple pendulum we would be (math-)famous. Well, he was right 😂

I love how simple the actual machine is; its the code and theory working the magic, not some particularly fancy machine itself

@DanielH212MC

Жыл бұрын

The precision capabilities of the machine also impresses me a lot. It probably has to perform such fine adjustments that we can't even see some of them.

@tomb816

Жыл бұрын

@@DanielH212MC Yeah, but precision CNC machines can hold tolerance to below 1 micron. The equipment and pc controls have been around for quite some time. The coding is definitely the feat of engineering that was accomplished w/ this demonstration.

@Bubu567

Жыл бұрын

@@DanielH212MC Closed loop servos are amazing. The feedback is being used to balance the pendulums. This feature has recently been coming to steppers as well, which will be amazing for hobbiest who can't afford servos.

@RuLeZ1988

Жыл бұрын

Not only the code itself does make it work. I believe each axis has different weights, and also the distance between the axis of the connection in the very background is shorter than the other connections. This physical Setup with these different weights play probably a very important role to make these transitions possible. I wonder if these transitions would be still possible, if the weight on each axis would be the exact same or if we then reach the limit in which it would not be impossible anymore to control the "triple inverted pendulum" like that.

@sixstringedthing

Жыл бұрын

@@RuLeZ1988 This demo is only possible due to the principle of inertia, which is a function of mass and force (a mass at rest will resist an applied force that attempts to move it in any direction, a mass in motion will resist any force that attempts to change the direction of that motion). The rig does not allow the designers to vary the force (torque) applied to the individual pendulum elements since they are free-swinging. Therefore, the only way this demonstration can work is if the pendulum elements all have a different mass, those masses being different enough to allow fine manipulation of input forces within the resolution of the control system/hardware so as to affect the elements individually and collectively with respect to their inertia within the bounds of some incredibly complex mathematical equations. The angular position/momentum feedback from each element (and the overall system) is then measured and corrected for at very high speed/resolution to arrive at the desired equilibrium. Of course, it should be possible to build such a machine with pendulum elements of the same length, as long as their masses were different enough to work within the resolution/frequency/tolerance confines of the hardware, control system and code. All of that said, I have absolutely no idea how bringing the masses/lengths of the elements closer together would affect the fiendishly complex calculations and coding required to make the machine reliably transition from any given equilibrium state to any other. That shit is just.... *boom* ... mind-blowing. :)

Holy crap this is probably one of the most amazing feats of engineering I've ever seen.

@DogmaFaucet

Жыл бұрын

Holy crap! I haven't seen you since the G+ days...

@ltmcolen

Жыл бұрын

If you like CNC machines you might enjoy this even more kzread.info/dash/bejne/ipWMp7SYj8-vhZM.html

@djmips

Жыл бұрын

I feel like it's something that anyone can appreciate.

@sunway1374

Жыл бұрын

How about the SpaceX rockets returning to land?

@vihreelinja4743

Жыл бұрын

lol

1:35 the instant stop is incredible

@kennyhubbell813

Жыл бұрын

I watched it a couple times because I thought it was a jump cut at first.

@bengravell5086

Жыл бұрын

Advancing frame-by-frame you can really see how the control algorithm knows to "stack" each of the links vertically from bottom to top. Incredible!

@Roach_Dogg_JR

Жыл бұрын

Looks like a reversed video almost.

@melody3741

Жыл бұрын

@@Roach_Dogg_JR all physics is technically reversible

@duckmeat4674

Жыл бұрын

@@melody3741 reverse my toast please

Any sufficiently advanced technology is indistinguishable from magic. - Arthur C. Clark

@rexus72

Жыл бұрын

This is definitely witchcraft.

@Kiteboardshaper

Жыл бұрын

Exactly what I thinking right the way thru this video, and I programmed an inverted pendulum system in my engineering degree

@MagnusWissler

Жыл бұрын

Clarke*

@arthurschildgen5522

Жыл бұрын

Arthur magic

@PanoptesDreams

Жыл бұрын

No it's called mathematics.

What I always love most about these kinds of things is when they transition back to the stable equilibrium; it's like, when they're going to any of the other states, it looks unnatural enough that my brain just takes it at face value, but when it's dropping back down suddenly my brain jumps in like "Hey, we've seen stuff like this (pendulums, rope, chain, etc.) dropping down and swinging around countless times, so we know what it'll look like here", and then it suddenly comes to a stop at the stable equilibrium with almost none of the usual swinging back and forth around it, and it just feels *wrong*

Of all the 56 transition controls for a triple inverted pendulum videos out there, this is by far my favorite.

As a non-engineer/mathematician I can only admire how this looks like a simple task but understand how incredible this is.

@SuperPhunThyme9

Жыл бұрын

I WANNA SEE FOUR

@flyingmoose

Жыл бұрын

Heck it’s hard enough to balance a broom on my palm, I can’t image a broom with a hinge, let alone 2 hinges…

@META_mahn

Жыл бұрын

As an engineer who studied this kind of stuff, the real ass pain behind this is the funky math that went behind all of this...the theory is simple however. Once you solve for the equations though, SimuLink is a really powerful tool and really can just handle a lot of this with some clever usage of computer logic. The real impressive part isn't even the balancing. It's the ability to send the machine from 0 to any state. Dealing with the "swing-up" control was probably the worst part about developing this.

Holy shit, this is amazing. I once programmed a controll function for a single inverse pendulum and I was so very proud when I could get it to stand indefinitely and adjust to minor aoutside influences after working on it for several weeks. I can't begin to immagine how complex the function for this has to be. I really hope you didn't have to sacrifice too many virgins to some elder god to acchieve this.

@labibbidabibbadum

Жыл бұрын

If it was anything like my university engineering lab, there would have been plenty of spare virgins available.

I dont know why KZread would recommend this to me but it's sure nice it did. the first transitions were impressive enough on their own but being able to switch between any equilibrium is mind boggling to me.

This is highly under-rated fundamental robotic control. Very nicely done indeed.

@VestigialHead

Жыл бұрын

Yes with this system you could make a robot that can balance much better than any human and walk and run and remain bipedal under nearly any circumstance.

@klerulo

Жыл бұрын

@@VestigialHead I am guessing that the software was built using IK formulae and a lot of PID constants, with a lot of manual tuning. Have you considered trying a neural model, giving it an external monitor to observe its own results, and letting it attempt to train itself?

@yuukil5522

Жыл бұрын

@@klerulothis is beyond simple PID control

@klerulo

Жыл бұрын

@@yuukil5522 I recognize that. Like I said, my guess is that this is based on formulae that encode inverse kinematics--but those formulae would suggest desired behaviors, which in turn would require driving the actuator to achieve those goals, and that requires basic PID. It's one element of what is likely very many, in a classical higher-level control loop. What I'm curious about is, could the same results be achieved using a neural, self-trained control mechanism instead?

@atomatopia1

Жыл бұрын

@@klerulo Theoretically speaking I’d say yeah it’s possible. I don’t know the details of this system but seems simple enough to represent mathematically and thus with sufficient design and training time would be possible to train a neural network to navigate.

I love the swagger with which it goes to the stable equilibrium, just stopping the motor for a bit is not cool enough 😎

@AlexTaradov

Жыл бұрын

It is not the same as simply letting it go. The idea of control is that you have optimization parameter, which is transition time in this case. Without active control it it would swing for a long time. In the recommended there is this video kzread.info/dash/bejne/n5mBucivkZCwmdI.html , which shows the difference between controlled and uncontrolled transitions.

@Synthetica9

Жыл бұрын

@@AlexTaradov oh yeah, I suppose the bearings would have to be super smooth, my brain imagined more of a dampening factor

@thomastendamme4059

Жыл бұрын

@@AlexTaradov Their 0 to 7 looks so clean!

What’s insane is you don’t see the man offshot while pulling the pulley ropes back and forth really quickly to make this all happen. Props to BTS rope guy.

@PronteCo

Жыл бұрын

I guess you could say you're a BTS stan

@MV-vv7sg

Жыл бұрын

@@PronteCo not so much into Korean Pop music sorry.

@ingenuity23

Жыл бұрын

@@PronteCo behind the scences

@PronteCo

Жыл бұрын

@@MV-vv7sg i know. It was a joke.

@Baneslayer

13 күн бұрын

Challenge accepted.

I would love to see this demonstration with lights on each pivot and a long exposure effect. That would look amazing!

@bencressman6110

Жыл бұрын

Brilliant idea

@Connection-Lost

Жыл бұрын

You don't have to say everything you think

@salender4683

Жыл бұрын

@@Connection-Lost Apply that to yourself

@harriehausenman8623

Жыл бұрын

@@Connection-Lost I just thought about that!

@noahtekulve2684

Жыл бұрын

​@@salender4683 love this

This is very, very impressive! It even feels a little scary, and I can’t even put into words why…

@boRegah

Жыл бұрын

Yes, exactly

@strykerjones8842

Жыл бұрын

The why is because these motors and systems are either currently or in the future will be what controls Boston Dynamics type robots. Spoiler alert they aren’t going to be dancing with them and they won’t be missing any shots like in the Terminator movies either.

@andrewfleenor7459

Жыл бұрын

It's profoundly, casually superhuman at a task you probably never considered just because it would be so ludicrously hard to do by hand, not just physically, like lifting something heavy, or intellectual, but both. And inverted pendulums are probably not the only thing it can do. Probably there are more practical applications that I also won't think of until I see them. For me it illuminates a gap in my imagination w.r.t the capabilities of robots.

@charlespatt

Жыл бұрын

I think it's because it reminds me of all the dancing skeleton cartoons I saw as a child! 😂

@Yora21

Жыл бұрын

This should not be possible! Logically we understand that it should be "technically possible", but the problem seems so complex that it's hard to believe it can actually be done in reality.

I'm completely amazed and the rest of my family brushes it off thinking I'm weird and not seeing the magic. Oh well.

@Petr75661

Жыл бұрын

maybe you have the knack... kzread.info/dash/bejne/dqxqqtGjfKXZnto.html

@99seaweed

Жыл бұрын

Lols, you have to understand how difficult it is to appreciate it. And it doesn’t help that the video makes it “look easy”

@saint79209

Жыл бұрын

It's like balancing 3 broomsticks on a finger.

It's a sad day for the world's first video of 55 transition controls for a triple inverted pendulum. But I think they can, together, share joy in this accomplishment. In all seriousness though, this is fantastic. This is the kind of robotics work that allows for the craziest kind of innovation that one would never expect if someone didn't work out the math and physics behind this, put it to code, and build a practical rig to demonstrate it. All of which are enormously time-consuming for this tiny, sub-10 minute video that only got recognition because its uniqueness makes it a prime candidate for success in a system of algorithm-driven content promotion. Imagine the wonder and inspiration this has inspired now, reaching a third of a million people! The value must be immeasurable.

Interesting how some transitions pass through intermediate equilibria. 6→2 and 2→6 are good examples of that.

@NoNameAtAll2

Жыл бұрын

yeah, it went through 5 briefly

I notice the pendulum segments are all different lengths - is that necessary for selective control of the individual segments? Like I notice in 2-> 5, the strategy relies on being able to swing the 3rd segment but not the first two

@joda7697

Жыл бұрын

it is necessary, yes

@tedshaneyfelt2263

Жыл бұрын

The different frequencies from the respective lengths must be the basis for some independence in control. Brilliant.

@chrisweaver41

Жыл бұрын

A+, impressive!

@megamaser

Жыл бұрын

It helps, but it's not strictly necessary. You can always disproportionately affect different arms even if they have identical dimensions.

@pyropulseIXXI

Жыл бұрын

@@joda7697 no, it is not necessary. These lengths do make it easier, though

I’ve spent so much time admiring and simulating double pendulums, exploring their intricacies and visualizing their evolution- and here you are stabilizing a TRIPLE pendulum with some algorithm that I can’t even begin to comprehend. This is seriously on another level

I like that the Most Replayed graph essentially plots the y coord of distal part of the 3rd arm.... we love those n->7 transitions!

@williamcampbell9859

55 минут бұрын

Omg you're right! Hahaha

이 영상이 만들어지기까지 얼마나 많은 대학원생분들이 희생되었을지 상상조차 가지 않읍니다...

@JustinMeyer

Жыл бұрын

"Many Bothans^Wpost-docs died to bring us this information" kekeke

@Nic7320

Жыл бұрын

All of them. They didn't go out and see daylight for three years.

@Scyth3934

Жыл бұрын

Translation: "I can't even imagine how many graduate students must have been sacrificed before this video was made..."

@sapienspace8814

4 ай бұрын

I may know of one 😉

The longer you watch, the more impressive you realize this is.

@billey30

Жыл бұрын

I'll be honest. Whenever I clicked on this video, I honestly didn't know what I was clicking on. And for the first minute or two, I was like "why is this video?" 😆. However, after a couple more minutes, I was LITERALLY blown away.!!!!

At first I thought the comments were being sarcastic. This video needs 8 billion views

The key is that each link is different length thus the natural swinging frequency is different for each link. By moving actuator at specific link resonant frequency it can move the desired link more than others. Nonetheless it’s incredible to see it in action working flawlessly.

@eitanspuzzles

Жыл бұрын

That is not very likely how it works. It's a PID control system, using a feedback loop to constantly tune the position of the cart.

@Matuterocks

Жыл бұрын

I've heard they use machine learning and chaos theory to achieve these what these machines do

@christianridings1870

Жыл бұрын

@@eitanspuzzles ain’t no way this is just PID control

@stevelentz9458

Жыл бұрын

If you look closely you can see mass added to the ends of 1 and 2, I think this is really the key, since the inertia of each segment will be different.

@aaronbeekay

Жыл бұрын

@@stevelentz9458 I think those are resolvers (to measure the angular position of the joints).

Well, there is a lot of math behind this. Loved it. This will definitely gather more attention in a close future.

I would not have anticipated the algorithm serving me 56 transition controls for a triple inverted pendulum, but here I am watching 56 transition controls for a triple inverted pendulum

The most important to me: It has a limited and quite small platform, so it must not only perform those tricks, but also adjust the pieces to then go back to the center Just aatonishing!

This feels very much like a pre-2010 YT video. The title says what the video is about, no commentary, and the comments are filled with impressed people. Good stuff!

I’m don’t think the average person realizes how insane and amazing this actually is.

@somal1anwarlord197

Жыл бұрын

No! Everyone knows how insane that is! We all played at some point with a pendulum

@parthenocarpySA

Жыл бұрын

Thank God the above average people like you can truly appreciate it

@swolleneyes

Жыл бұрын

The insane person realizes how average and actually this amazing think do

@dannlefou7070

Жыл бұрын

@@swolleneyes I love you.

By far one of the best transitions is at 4:25, from 1 to 7, truly amazing

from 6:55 - 7:30 are my favorite series of transitions

@grantcivyt

Жыл бұрын

Those were very cool. Thanks for linking. I was about to leave early! 😀

@_wetmath_

Жыл бұрын

yeah same

I didn't know what this video was gonna be, but it now certain feels like one of the best videos I'm gonna see in a while.

It's incredible how these brilliant minds could control the 56 transitions of a triple inverted pendulum but failed miserably at hanging a black sheet without wrinkles

@anthonyrepetto3474

4 күн бұрын

Your comment illuminated so much of what felt odd to me about this... thank you!

This is absolutely incredible! How hasn’t this video broken a million views?

@jacotacomorocco

Жыл бұрын

Few people understand the achievement sadly..

@myfatassdick

Жыл бұрын

I’m pretty sure it’s a reupload because I remember commenting on this a few years ago but now it’s not here and this was only from 7 months ago

@NotMe-ej9yz

Жыл бұрын

1) The video name is incredibly complicated to decipher if you don't already know what this is so why bother watching something when you don't even understand the name. 2) it's 10 minutes long and most people nowadays aren't gonna invest that much time to watch something they've never heard of. And 3) it's a video about math, robotics, and physics so most normal people aren't interested (or actually hate in the case of math and physics) those topics. We obviously aren't most people lol Bonus answer: The thumbnail sucks

Can’t wait to see what six flags does with this technology

Very impressive control performance. I wrote a Master Thesis for twenty five years ago for double inverted pendulum using Robust control, which was the hot topic at that time. The mechanic construction didn't aloud each pendulum to rotate fully around, so the start was done by hand to level both in upright position. The order for the controller went sky high and the loop shaping weight was designed for using the two eigenvalues for the pendulum otherwise the motor didn't have power enough.

I might be a nerd but this is more fascinating than 99% of the content I've seen in the past 5 years.

That is just the biggest flex I've ever seen. Just wow.

As an engineer, just seeing this makes me wonder the level of numeric methods and computing processing that this took, truly amazing

I'm not into engineering and I have no idea why this video was suggested, nor why I clicked on it. But I'm glad I did. That's truly incredible 👏

I have no idea what this is or why the algorithm decided to bless me with it, but I dig it. Thanks, algorithm. Thalgorithm.

The 3-6 and 6-3 transitions are straight fire 🔥🔥🔥

Reminiscent of an acrobat lifting up above their head and balancing a teammate on their hands, then letting them down again. Amazing how not just a double but a triple pendulum can be controlled with enough sensory feedback. Amazing!

Simply astounding. My knowledge of control theory and design practice is pretty limited, but even at my layperson level I can understand how impressive this project is. I would love to know if this demo rig and its control software were developed by building a double pendulum iteration first, or whether the designers just decided to aim high and went straight for developing this Big Daddy version! Edit: I've just gone through the mental process of trying to figure out how to explain why this video is so cool to my family and friends, and the more I think it through the more mind-bendingly complex and impressive it gets. I've kinda sorta got a handle on how the various equilibrium states are achieved, on a theoretical level at least (no idea how the math would be translated into functional code though). But cleverly stringing subroutines together to go directly from any given state to any other without passing through a known stable equilibrium on the way is simply magic as far as I'm concerned.

I don't know why 'the algorithm' sent me here, but it is truly wise and knows all our needs.

FLIPPING MAGICIANS!! I can;t even comprehend how much time you must have spent to achieve this precision madness!!

this is incredible mastery of control

Unbelievably cool. My mind is blown.

this is insane and so cool! the fact that it manages to make some of those unstable eqs look almost stable is wild, and it does it effortlessly

The mathematics and physics of this should be STRICTLY beautiful. But this is just more than math and physics. This is art found with hard science. This is simply beautiful.

This was absolutely mesmerising. It feels alive. Jovial. Mischievous. Those slow smooth slides maintaining balance? Damn. Phenomenally impressive. Bravo.

going from 6 to 7 is wild that's some damn precision

Love the mini servos in each joint!

I don't often watch triple inverted pendulum control videos, but when I do they are from the Embedded Control Lab.

더 많은 공학도들이 이 영상을 보고 영감을 받으면 좋겠네요.

This is some of the most beautiful motions I have ever seen

What I love so much about things like this is that it shows something that looks pointless, but behind the scenes, this kind of control mechanism is what makes a lot of stabilization systems work, and helps the world function better and better. While not directly comparable, at least some of how this must function lies within aircraft autopilot systems, cruise control in most cars, and probably some of the "magic" stuff smart phones can do utilizing their sensors while taking video or photographs.

What a random recommendation from KZread wtf, this is very impressive but is it truly the world's first of this kind?

영상 유익하네요!!

So impressive !

It is devastating. As a kicked-ass student who tried to deal with gain scheduling in master programme of control, I can just say congratulate you. I noticed that the controller oscillates to keep some unstable equilbriums stable. You may reduce those oscillations but still it is amazing. Thanks.

The amount of transitions in these controls is impressive.

Out of all of the triple inverted pendulum transitions, that was certainly all of them.

I am not that good in maths but I read how chaotic pendulum systems can be. Triple! This is incredible.

That must have taken the whole afternoon to figure out the equations for that

The fact that this is done with just 1 actuator is mind blowing

This... Was one of the best thing i've ever seen There are three me that are wondering: 1) How do i construct a physics theory to properly describe when and how to give/remove energy from the system to make it do this? 2) How do i set up machines and sensor in a way that can give me feedback fast and acurate enough to properly balance it even when it's in his most unstable equilibrium spot? 3) How do i program a feedback loop that can automatically do small correction based on the points above? i'm a physics student and my friends are another physics students, an automation engineering student and a informatic student (not sure about specializations) so this was spectacular thinking about every part of our studies... I loved seeings this

@chrisdonnell7200

Жыл бұрын

The tools for this are called "control theory", they involve a good bit of physics and math from multiple domains. It's a very deep subject, and this triple pendulum is non-trivial to control the way they do. However, single "cart-pendulum system" (good thing to Google) are pretty standard control subjects that many university students do, and would definitely be both reasonably achievable and a great starting point for this if you wish to get more complex in future.

@chrisdonnell7200

Жыл бұрын

The simplest control strategy is something you've probably heard of, the PID controller. In essence it's saying "if I want something to go in X direction, I should apply X input", intuitive enough from Newton's Laws. PID is good enough to balance a single cart-pendulum. After that you can get into linear controls, which essentially generalizes the PID system and utilizes linear algebra to more formally describe and control a system. For a system as complex as the triple pendulum you almost certainly need more complex, non-linear/optimal control systems which are much more difficult to design.

@silver_3552

Жыл бұрын

@@chrisdonnell7200 thanks a lot, i will most certainly check it out... After i give my next exam that is almost a week from now

@scowell

Жыл бұрын

@@silver_3552 Basically, an inverted pendulum... a controlled rocket is very similar to an inverted pendulum.

@silver_3552

Жыл бұрын

@@scowell i see, that's an interesting analogy that i didn’t think of... There is so much to learn and i'm really glad i've written that message and to all that have responded giving me something to search

This is excellent. However the numbers (start and target equilibrium, shown at top-right) are difficult to follow 'intuitively'. A better visualisation might be to keep the table (shown at 0:13 - 0:21) onscreen, and fill-in the boxes as the demonstration progresses. For example, using 'amber' to indicate which transition is about to be done (or is in progress), then 'green' once that transition has been achieved. (Or perhaps hashed- and then solid-colour, for the benefit of those who are colourblind.) I would also be interested to know how the relative-lengths of the pendulums affects the feasibility of this demonstration. I would guess that the three pendulums need to be different lengths, such that different frequencies of input motion will affect each pendulum differently. But is the order significant? ( 'Short-medium-long', versus 'long-medium-short', 'medium-long-short', etc.) I could also be wrong... is it possible with three pendulums of the same length?

@urimiroo

Жыл бұрын

Thank you for the suggestion. We will think about it later. For the length of the pendulum, we use the following rules: short-medium-long as shown in the video. Same length is not a good idea because the mechanical structure prevent it from happening.

@CatNolara

Жыл бұрын

iirc same length pendulums would mean you could get singularities, which are not desirable. Like imagine the first joint being at 0 degrees and the second at 180 degrees, then the third joint would be exactly in the same axis as the first joint and become uncontrollable. On the maths side it would make the equations to divide by zero or something similar in that point.

@urimiroo

Жыл бұрын

@@CatNolara If all the pendulums have same length, then they will collide while they are rotated. Remember that we have to install a rotary encoder at each joint. It means that it needs some space to avoid the collision.

@InTimeTraveller

Жыл бұрын

@@urimiroo if the problem is purely structural, would it be a solution to have the pendulums offset from each other in the z direction (while they are laying flat)? As in, have the pendulums not almost touching but a bit more spaced apart in order to have room for the encoder? I guess this is going to require a lot extra work to mount them that way though. But anyway, the question I guess is, do the physical dimensions of the pendulums play a role into the model? Does the system need to be modelled differently if you put in different size pendulums (or different size order) than the ones you have now?

@InTimeTraveller

Жыл бұрын

@@CatNolara what you're describing is irrelevant of the lengths of the vectors, but is an artifact of using Euler angles to describe rotations and it's called gimbal lock. That is why you don't use Euler angles to describe the rotations of 3 axis systems but you use quaternions (which are essentially vector representations of 3D rotations) and then you avoid this problem.

This is amazing. Congratulations ans all my respect for the builder. It deserves the length of its title.

The way it matches the swing speed for balance is incredible

During my automatic control studies in the 1990's I was still tought, that this is assumed be im possible due to the missing mathmatical proof. I like this demonstration of scientific development and progress. Congratulations.

@joshuahudson2170

Жыл бұрын

I'll bet there's still no math proof either, and the PIC just assumes a solution exists and happens to work.

@KristopherBel

Жыл бұрын

I was also taught this was impossible because of the lack of a proof, but watching it started to doubt I was taught that, so thanks for your comment.

@Cineenvenordquist

8 күн бұрын

Like, heat death of universe stability or gtfo, or you never saw poipoi dancers?

If I try really hard, I can sometimes balance a broom on my finger.... so, I got that going from me.... which is nice...

This is awesome. Firstly, its a single input multi output system, and these are intrinsically difficult to control. I suspect that it is seriously non-linear because of the trig functions as the elements go around their circles. The distal element are longer (= slower response ) that the medial elements. I think this is the only thing that allows it to work. If the distal pendulums were faster that the medial ones then you couldn't make the medial ones respond fast enough to control the distal ones and it would all go to crap. All in all this is VERY impressive my master thesis (a long time ago in a galaxy far far away) was in time optimal position control. One of the texts we studied was by workman and emani-nani and they had a scheme called XAPTOS (for extended approximate time optimal position control. That system used an extra set of poles (Blocking zeroes? its been a long time) to add an oscillatory mode so the output stays constant as the system settles. Apparently it is used in container ship unloading cranes to move the containers containers as fast as possible. The crane cab oscillates back and forth while the container moves smoothly up and down from ship to truck or vice versa.

I didn’t expect to be so amazed

It's unstable at some of the positions, but the non-linearity of the geometry stabilizes it. Excellent work!

@rarebeeph1783

Жыл бұрын

I'd imagine the majority of the stability is achieved through powered microcorrections, moving the base to adjust the angles of the pendulums relative to each other.

@crackwitz

Жыл бұрын

ALL of these except position 0 (all down) are unstable. The point of this thing is indeed that the apparatus counters, using motions of various magnitude and speed.

Is there a research paper or some simulink code I may view?

My gosh that’s amazing. Next they will solve the three body problem.

truly, one of the videos of all time.

now this is some big brain stuff

I find this strangely relaxing to watch. It also made me laugh out loud, probably because I imagined the machine to be sentient as it performed one feat of juggling after another. I could almost hear it saying "Huuu...UUP!!" I clapped at the end.

It really says something about how insanely precise this machine is that it makes this look so easy.

You are wizards of mechanisms!

Fascinating.. But what do you do with this?

@urimiroo

Жыл бұрын

It's a benchmark plant for lots of control engineers. Furthermore, people who do research on reinforcement learning, this system is a great challenge. For classical control engineer, this system can be used for education purpose because, to swing this up, we need great amount of knowledge on control theory.

I'm a programmer and not an engineer but this is very cool. Some really neat behind the scenes stuff I bet and lots of hours.

this is the stuff i want youtube to recommend me

That is a really impressive amount of control.

Holy shit.

@andyhervert9650

Жыл бұрын

*Pinned comment*

@hdheuejhzbsnnaj

Жыл бұрын

@@andyhervert9650 If I show people this and they don't understand why this is impressive I know we'll never be friends. It's really handy to have this quick social filter, and explains at least 20 of your views.

impressive! Are you now working on the 240 different transitions for a quad - pendulum ?

I've seen the 55 transition controls for a triple inverted pendulum a million times but I never thought I'd get to see the 56 transition controls for a triple inverted pendulum in my lifetime.

Science voodoo! Dead limbs standing! Very cool transitions, incredible work.