Learning athletic humanoid tennis skills from imperfect human motion data

danielmorozoff 137 points 28 comments March 15, 2026
zzk273.github.io · View on Hacker News

Discussion Highlights (11 comments)

KolmogorovComp

Nothing constructive to say, besides that the video really shows we're entering into a Sci-fi era.

Void_

This just makes me want to play tennis right now. Such an addictive sports.

Aboutplants

Really impressive. In a few years there will be robotic AI instructors for the wealthy and their kids

ordu

It is interesting to watch. The movements of the robot are robot-like. I mean, wtf, there were no robot playing tennis before, but I have an idea how a robot playing tennis would be like, and this video confirms my expectations. Sharp, unsure movements, a lot of hesitation, ... Movies pictured robots like this long before this become possible, but how did producers guessed it? Or maybe movies rendered different kinds of robots, but this video bring into my memory only those, that look like this. A kind of confirmation bias?

ohyoutravel

Why can some Temu humanoid robot do this sort of impressive, coordinated, high-speed thing, but Tesla Optimus completely sucks at everything unless they’re moving at 0.02m/s (and even then they’re not great)? Like, train this thing on the latent space of folding my clothes out of the dryer and I will send you my money.

blueblisters

Very impressive. But it doesn’t solve the whole problem yet. The robot and ball pose is estimated by high speed mocap cameras, and is fed to the policy. I imagine estimating that with onboard cameras - how humans do it - is much harder. Almost all of closed loop robotics is a state estimation problem. Control is “solved” if you can estimate state well enough.

hbcondo714

Impressive! Looks like a nice alternative or evolutionary step for a ball machine. Either way, teach it to serve :)

V__

This is so interesting. Especially since it's kinda weird to train a robot to mimicking human play. I wonder what a perfect robot what actually behave like. It wouldn't need to split-step to activate muscles, the footwork would probably be minimal. I imagine a lot of different unusual looking swings to confuse human players, while still making perfect contact. It could make really late drop shots or even rotate the racket at the last moment for crazy angles. Would love to watch this.

ilaksh

We have just started ramping up practical use of imitation learning from human demonstrations in humanoids. A bigger development is that one or two projects are working on training foundational vision action language models based on large video datasets. I think before the end of summer general purpose physical knowledge and capabilities will start to be demonstrated by one or more humanoid AI or robotics groups. Maybe 18 months at the absolute latest. I'm guessing by next year or 2028 there will be services where you can order a robot to come cook and or clean for you. By 2029 it should be quite affordable to get a humanoid on a short term rental. Do we have any standard benchmarks for humanoids to do domestic tasks?

kace91

Now we intellectual workers can race physical workers to see who becomes obsolete first!

sam1r

So this is all pretty much theoretical, but very tightly woven strictly bounded protocols to be brought to production-- perhaps an accelerated alternative to perceive a much sooner ETA of 18months... Maybe its moreso about reaching out to the right people about this "white paper" worthy research. AFAIK, billions of dollars are poured into tennis mechanics at the highest level. Introduce this to the right group of people, I truly can see this funded to play Janik Sinner where he would pay as a service to play against his worst nightmare.

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