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IliaLarchenkoĀ 
posted an update 2 days ago
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I placed 🄈 2nd in the LeHome Challenge (ICRA 2026), and šŸ„‡ 1st of 62 teams in the first simulation round. Now I'm open-sourcing the full solution — code, tech report, and final weights.

The task: teach a cheap two-armed robot (SO-ARM101) to fold 4 garment types — long/short tops and pants. Garment category is hidden at eval. Round 1 in sim (auto-scored), round 2 on a real robot (jury-scored).

I trained a VLA policy with an RL loop on top. The key ideas:

🧠 The policy is its own value function. From the same forward pass that picks the next action chunk, cheap heads predict success probability, task completion %, garment type, and future keypoint distances + a Q-residual. Those become the advantage signal for RL — no separate critic.

šŸ” A fully asynchronous RL loop coordinated only through the HF Hub: 1 trainer (H200) ships a fresh checkpoint ~every 40 min while N rollout workers (and a human doing teleop / DAgger corrections) collect data in parallel. Nobody waits — it uses the off-policy nature of the loop to the fullest.

šŸ“ˆ Binary success is too sparse, so I densify it into per-frame advantage via GAE — from objective keypoint checkpoints, the success-probability value baseline, and completion %.

šŸŽ›ļø The RL combines AWR + RECAP. I also tune the inference knobs — execution length, playback speed, inpainting overlap, CFG scale, best-of-N — with a per-parameter Thompson-sampling bandit folded into rollout collection.

šŸ”§ Round 2: with only ~1 week and no access to the eval robot — so the pipeline was sim → my robot → their robot, leaning on heavy augmentation to make the policy more robust.

šŸ“ Blog: https://ilialarchenko.com/projects/lehome2026
šŸ“„ Tech report: Learning to Fold: prizewinning solution at LeHome Challenge 2026 (1st place online, 2nd offline) (2606.27163)
šŸ”§ Code: https://github.com/IliaLarchenko/lehome_solution
šŸ¤— Sim policy: IliaLarchenko/lehome_sim
šŸ¤— Real policy: IliaLarchenko/lehome_real
🌐 Challenge: https://lehome-challenge.com/
IliaLarchenkoĀ 
posted an update 7 months ago
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šŸ† BEHAVIOR Challenge 1st Place – Solution Summary

My team recently won 1st place in the BEHAVIOR Challenge at NeurIPS.
The competition focused on training a single policy to complete 50 long-horizon household tasks in simulation.

We built an end-to-end policy based on Pi0.5 with a bunch of custom modifications. Everything is open-sourced, and it should be useful for anyone exploring VLAs or adapting them to specific tasks.

Key Architecture Changes:
- Replaced language model with 50 trainable task embeddings (no text at all)
- Correlated noise for Flow Matching: ϵ ∼ N(0, 0.5I + 0.5Σ) using dataset action covariance
- Learnable mixed-layer attention: each action expert layer attends to a trainable mix of all VLM layers
- System 2 stage tracking: model predicts task stage, we smooth it with voting and feed it back as context

Training:
- Multi-sample Flow Matching: 15 FM samples per VLM pass to reduce gradient variance
- Delta action space + per-timestamp normalization
- FAST auxiliary loss and stage prediction loss
- Trained on 224Ɨ224 RGB + proprioception only
- We use 4 fine-tuned checkpoints, all derived from a multi-task model trained on all 50 tasks

Inference Optimizations:
- Soft inpainting: predict 30 actions, execute 26, use 4 as an input for the next chunk
- Correlation-aware guidance of inpainting to keep action chunks smooth
- 1.3Ɨ speedup via cubic spline compression
- General correction rule: reopen gripper after failed grasps

šŸ”— Code and Models:
- Code: https://github.com/IliaLarchenko/behavior-1k-solution
- Weights: IliaLarchenko/behavior_submission
- Paper: Task adaptation of Vision-Language-Action model: 1st Place Solution for the 2025 BEHAVIOR Challenge (2512.06951)
IliaLarchenkoĀ 
posted an update over 1 year ago
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I am presenting Decoder-Only Transformer (DOT) Policy a simple Behavioral Control policy that outperforms SOTA models on two simple benchmark tasks:

āœ… PushT (pushing an object to a goal) – 84% success on keypoints, 74% on images (previous best: 75% / 69%)
āœ… ALOHA Insert (precise bimanual insertion) – 30% success (previous best: ~21%)

The best part? DOT is much smaller (sometimes 100 times less parameters) than previous SOTA models, trains faster, and avoids complexity:
🚫 No generative models (Diffusion, VAE, GANs)
🚫 No discretization/tokenization of actions
🚫 No reinforcement learning or multi-stage training
āœ… Just learns from human demos, plain and simple

This is still early — more complex real-life tasks need testing, and no guarantees it will actually work well there, but I think it's interesting to share. Sometimes, simpler approaches can be just as effective (or even better) than complex ones.

šŸ”— Open-source code and detailed description: https://github.com/IliaLarchenko/dot_policy

Trained models on Hugging Face:
IliaLarchenko/dot_pusht_keypoints
IliaLarchenko/dot_pusht_images
IliaLarchenko/dot_bimanual_insert