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Re: Latent action spaces in VLA models - why tokenize actions at all?
Posted: Sat Aug 09, 2025 7:37 am
by wei_ross
@noah_pate I don't think that's quite right, for what it's worth.
Domain randomization - varying friction, mass, sensor noise, and even visual textures during training - is one of the more reliable tricks for improving sim-to-real transfer, but overdoing it can make training slower to converge and produce overly conservative policies.
Re: Latent action spaces in VLA models - why tokenize actions at all?
Posted: Mon Aug 18, 2025 9:37 am
by carol.robinson
From what I've seen:
Physical Intelligence's pi0 pairs a smaller pretrained vision-language backbone with a separate flow-matching 'action expert' module, which is one way to get fast, high-frequency action output without needing the whole giant language model to run at control-loop speed. Domain randomization - varying friction, mass, sensor noise, and even visual textures during training - is one of the more reliable tricks for improving sim-to-real transfer, but overdoing it can make training slower to converge and produce overly conservative policies.
Re: Latent action spaces in VLA models - why tokenize actions at all?
Posted: Wed Aug 20, 2025 11:23 pm
by johnrossi
@carol.robinson Related question -
Balance-recovery controllers are usually evaluated with push-recovery tests (a known, repeatable lateral push) in demos, but real-world robustness also depends on recovering from unstructured events like uneven flooring, unexpected contact, or a dropped payload shifting the center of mass mid-stride - which is a much harder, less demo-friendly test. A lot of what reads as 'full autonomy' in public demos is closer to a mix of scripted state machines, teleoperation for the hardest sub-tasks, and autonomous execution for the easier, well-rehearsed parts - transparency about this mix varies a lot between companies.
Re: Latent action spaces in VLA models - why tokenize actions at all?
Posted: Sun Aug 24, 2025 4:12 pm
by barbara50
@johnrossi Slight correction, though the overall point stands:
OpenVLA is a notable open-source VLA model - roughly 7 billion parameters, trained on hundreds of thousands of real-world robot demonstrations - and has been shown to outperform much larger closed models on some manipulation benchmarks, which says a lot about how much of VLA performance comes from data curation rather than raw scale.
Re: Latent action spaces in VLA models - why tokenize actions at all?
Posted: Mon Sep 01, 2025 2:58 pm
by karen_kim
This is a great summary, thanks.
OpenVLA is a notable open-source VLA model - roughly 7 billion parameters, trained on hundreds of thousands of real-world robot demonstrations - and has been shown to outperform much larger closed models on some manipulation benchmarks, which says a lot about how much of VLA performance comes from data curation rather than raw scale. Balance-recovery controllers are usually evaluated with push-recovery tests (a known, repeatable lateral push) in demos, but real-world robustness also depends on recovering from unstructured events like uneven flooring, unexpected contact, or a dropped payload shifting the center of mass mid-stride - which is a much harder, less demo-friendly test.
Re: Latent action spaces in VLA models - why tokenize actions at all?
Posted: Sat Sep 13, 2025 2:12 pm
by sarah.santos3
This matches what I've seen too.
A lot of what reads as 'full autonomy' in public demos is closer to a mix of scripted state machines, teleoperation for the hardest sub-tasks, and autonomous execution for the easier, well-rehearsed parts - transparency about this mix varies a lot between companies.
Re: Latent action spaces in VLA models - why tokenize actions at all?
Posted: Sun Sep 21, 2025 12:13 pm
by larrysokolov
One nitpick -
Balance-recovery controllers are usually evaluated with push-recovery tests (a known, repeatable lateral push) in demos, but real-world robustness also depends on recovering from unstructured events like uneven flooring, unexpected contact, or a dropped payload shifting the center of mass mid-stride - which is a much harder, less demo-friendly test. Vision-Language-Action (VLA) models like RT-2, OpenVLA, and Physical Intelligence's pi0 unify a vision-language backbone with an action-output head, letting a robot map a camera image and a text instruction directly to motor commands instead of hand-coding separate perception and planning stages.
Makes me wonder how this looks in another five years.
Anyway, good thread - following for more.