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Triple inverted pendulum in transition control A classic control problem, done in real time. This setup moves smoothly between all eight equilibrium points of a triple inverted pendulum. The system reacts every 1 millisecond, which shows how fast modern control loops can be. • Real-time control at 1 ms...

168,186 views • 9 months ago •via X (Twitter)

48 Comments

srinivijay's profile picture
srinivijay9 months ago

Great demonstration. I know a regular inverted pendulum is the principle behind Segway and similar tech. Where is the triple inverted pendulum used?

Ilir Aliu's profile picture
Ilir Aliu9 months ago

mainly employed in research and education to test advanced nonlinear control algorithms, with emerging applications in robotics for multi-joint stability, aerospace for attitude control, and biomedicine for prosthetic limb balancing

Darren Dawson's profile picture
Darren Dawson9 months ago

Hello 3 body problem

Ilir Aliu's profile picture
Ilir Aliu9 months ago

illustrating how modern algorithms tame chaotic systems

Ikario's profile picture
Ikario9 months ago

@Darren_Dawson And more than 3 ?

Tvirtāks's profile picture
Tvirtāks9 months ago

@IlirAliu_ @Darren_Dawson Give it to a control systems student and don't tell them it's any difficult

Ikario's profile picture
Ikario9 months ago

@IlirAliu_ @Darren_Dawson Yeah like cold fusion 🤭

Tvirtāks's profile picture
Tvirtāks9 months ago

@IlirAliu_ @Darren_Dawson I think you're confused a bit This isn't a "solution to 3 body problem" like some xeeters claim That's a completely different thing The pendulums are kept actively outside the chaotic realms. The video is not ~solving chaos nor ~predicting general movement

Darren Dawson's profile picture
Darren Dawson9 months ago

@ikario404 @IlirAliu_ I know, attire is dead, I forgot.

T's profile picture
T9 months ago

Wow. Impressive. I bet most people don't realize the complexity behind this. From modeling to actuation. What's the feedback system? Vision?

Ilir Aliu's profile picture
Ilir Aliu9 months ago

feedback system relies on four encoders measuring cart position and pendulum angles, combined with a time-varying Linear Quadratic controller for error correction, rather than vision-based sensing

Camilla Mazzoleni's profile picture
Camilla Mazzoleni9 months ago

I remeber doing this project with an RL agent during my probabilistic AI course at ETH, very fun project

Ilir Aliu's profile picture
Ilir Aliu9 months ago

And footage pics of that time?

Ki's profile picture
Ki9 months ago

'The system reacts every 1 millisecond, which shows how fast modern control loops can be.' Interesting point... Humans can't even perceive sub 4ms. I'm to understand this robot is operating at about .25ms to accomplish trajectory tasks.

Nav Patel's profile picture
Nav Patel9 months ago

This will be my go-to video when I'm trying to describe to a non-technical person why self-driven cars are better than human ones.

Dwight Crow's profile picture
Dwight Crow9 months ago

holy shit. that's superhuman

OobyVoots's profile picture
OobyVoots9 months ago

> reacts every millisecond must be written in python

John Denney's profile picture
John Denney9 months ago

1 ms sampling is slow in computer time. I worked on a microprogrammed disk controller in the early 1980s that had delay loops to wait for the next bit to be read. One bit took about 250 nanoseconds to arrive. The slow part is the positioning solenoids.

Brandon Kirkpatrick's profile picture
Brandon Kirkpatrick9 months ago

This is cool! I saw a similar animated video (Pezza's Work - YouTube) using neural nets for control.

Ilir Aliu's profile picture
Ilir Aliu9 months ago

Can you find it again?

Brandon Kirkpatrick's profile picture
Brandon Kirkpatrick9 months ago

I just sent you a DM.

Michael Odden's profile picture
Michael Odden9 months ago

This is certainly a cool project. But re "how fast modern control loops can be": I was working on systems with 1ms sampling 15 years ago, and that was on a legacy product even then. The only area where I've met people treating 1ms as fast is web.

the Rich's profile picture
the Rich9 months ago

@DanielleFong @asingleoat

Dan McCarty's profile picture
Dan McCarty9 months ago

sorry but 1ms is pretty slow. try usecs or even nsecs for tight loops.

Ray Hunter's profile picture
Ray Hunter9 months ago

Impressive. When I was studying, the single inverted pendulum was cutting edge control theory. Now kids have access to all sorts of balance balls and wheels and theory has moved on significantly.

The Panic's profile picture
The Panic9 months ago

Incredible.

Todd Shaw's profile picture
Todd Shaw9 months ago

Humans don't stand a chance😵

Jim Lux's profile picture
Jim Lux9 months ago

Indeed. But a more impressive inverted pendulum example is Astra’s ill fated launch 3.2 with the rocket translating sideways, stably.

Lincoln Margison - Game Development's profile picture
Lincoln Margison - Game Development9 months ago

Is this learnt (RL etc)? Or is it 'solved' where there's an answer/formula?

Man of La Mancha's profile picture
Man of La Mancha9 months ago

Very impressive transitions. Millisecond operations are slow though, I wonder what that comment refers to?

Lord of Bathrobes's profile picture
Lord of Bathrobes9 months ago

are you using gym to train the model which controls this or am i misreading the engine behind all this

Ilir Aliu's profile picture
Ilir Aliu9 months ago

Video that I found and thought it would be interesting to share

Lord of Bathrobes's profile picture
Lord of Bathrobes9 months ago

the comments in the yt video are perfect. describing physics as 'evil magic' is sorta lyrical from the right perspective. also surprised this is 2 years old.

Oskar's profile picture
Oskar9 months ago

I like how it thinks it needs to do a transition swing to get from the second lowest to the lowest state 😆👍

Ascanio 🌍☮️'s profile picture
Ascanio 🌍☮️9 months ago

Matlab über alles 🤩

Nicholas Shanks's profile picture
Nicholas Shanks9 months ago

I can do the last one.

Faber Tornator's profile picture
Faber Tornator9 months ago

It is probably way harded to do this than to control the landing of those rocket first stages.

Alter3D Reality's profile picture
Alter3D Reality9 months ago

OK guys, we've solved chaos now, and we..... *looks at the state of the world* never mind.

Stephen Schwinn's profile picture
Stephen Schwinn9 months ago

Control engineering p0rn. Love it!

Andréa Gourion's profile picture
Andréa Gourion9 months ago

Really stunning! Is it done with an RL controller or with a model-based framework?

Michal Broniek's profile picture
Michal Broniek9 months ago

Wooooow!

tweirdude's profile picture
tweirdude9 months ago

This is the most impressive thing I've seen today, it's absolutely amazing how the robot manages to control a triple pendulum considering the difficulty of a two pendulum problem, this is insanely beautiful

Søren Reinke's profile picture
Søren Reinke9 months ago

Wow that is really amazing :)

Chris P Bacon's profile picture
Chris P Bacon9 months ago

really impressive

Lőrinc Bauer's profile picture
Lőrinc Bauer9 months ago

😱😱

Long ph's profile picture
Long ph9 months ago

Impressive! Is there a github repo?

Jędrzej Michalczyk's profile picture
Jędrzej Michalczyk9 months ago

Cool, funny thing I made a double pendulum simulation a few days ago. It targets embedded control like this, checkout if you want to go possibly faster than simulink generated code.

Selim Şeref Kara's profile picture
Selim Şeref Kara9 months ago

Not optimized code is detected! Last move was totally unnecessary, simply stop would have been sufficient to drop.

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