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F1-VLA

Shanghai AI Laboratory, Harbin Institute of Technology (Shenzhen) · 2025-09

VLAFlow·Diffusion VLA4.2Bflow matching

A VLA that generates future visual scenes (foresight) in a next-scale manner before actions and uses them for planning.

View architecture diagram in the galleryPaper ↗

Paper

F1: A Vision-Language-Action Model Bridging Understanding and Generation to ActionsarXiv 2509.06951

Overview

Category
Flow·Diffusion VLA
Type
VLA
Released
2025-09
Organization
Shanghai AI Laboratory, Harbin Institute of Technology (Shenzhen)
Open weights
Yes
Parameters
4.2B

Architecture

Backbone LLM
Gemma · PaliGemma initialization
Vision encoder
SigLIP (PaliGemma)
Action head
foresight generation + flow matching expert (flow matching)
Chunk
Not disclosed
Control rate
Not disclosed
Architecture (original summary)
Mixture-of-Transformer: understanding expert (PaliGemma initialization) + foresight generation expert (VAR residual VQ-VAE next-scale, 4 scales at inference) + flow matching action expert (inherited from π0)

Training

Pretraining accelerators
Not disclosed (no GPU type·count·time in App. B)
Pretraining duration
Not disclosed
Pretraining steps & batch
Stage I 512K steps·batch 1280·lr 3.0e-4 (cosine); Stage II 100K steps·batch 2880·lr 5.0e-5 (constant)
GPU/TPU-hours
Not disclosed
Fine-tuning
Stage III batch 128·lr 5.0e-5 (cosine), hardware·time not disclosed; post-training on about 1.8K in-house trajectories
Data type
Real-robot teleoperation + simulation (LIBERO)
Data scale
330.9K trajectories · 73.8M frames, 136 tasks, 5 embodiments (AgiBot-World 187K/66.4M, Bridge-v2 53.2K/1.9M, Fractal 87.2K/3.8M, LIBERO 1.7K/0.3M)
Main datasets
AgiBot World, OXE Bridge v2, OXE Fractal, LIBERO
Tasks & evaluation
LIBERO 98.2/97.8/95.4/91.3, average 95.7; SimplerEnv Bridge 72.9; Genie real-robot 9 tasks average 82.2% (grasp 92.6%)
Robot
Genie G1, Franka, ARX LIFT II, WidowX, Google Robot (single-arm·bimanual)

Inference

Inference device & speed
Not disclosed (limits foresight to 4 scales for real-time control)
Inference memory
Not disclosed
Weights bf16 (calc.)
8.4 GB
Where it runs
Not disclosed

Reinforcement learning & base

Reinforcement learning
Not used · Imitation learning (behavior cloning) only
Base control
Fixed · No mention of base movement (Genie-1·ARX LIFT II manipulation; dynamic tasks use a conveyor belt)

Notes

Key features
A VLA that generates future visual scenes (foresight) in a next-scale manner before actions and uses them for planning. Achieved 82.2% average success rate on 9 real Genie tasks.
Notes
Initialized from the π0 action expert·PaliGemma (README requires lerobot/pi0_base). App. B hyperparameters newly confirmed in verification (Unverified in notes).
Verification
Corrections applied

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