7-Day VLA Project: MuJoCo + π0-3.5B + BC-Z for Franka Panda Virtual Cup Grasping
Project Goal
No physical robot, pure simulation: input natural language commands like "Grab the cup and put it on the right side of table", and watch a virtual Franka 7-DOF robotic arm autonomously complete visual recognition → motion planning → grasp cup → place on right side of table — a complete VLA (Vision-Language-Action) closed loop.
Minimum Hardware Requirements
- GPU: RTX 3060/4060 with 12GB VRAM (required)
- CPU: 6+ cores
- RAM: 32GB recommended / 16GB minimum
- OS: Ubuntu 22.04 (WSL2 Ubuntu works; native Windows not recommended for MuJoCo)
- Timeline: 7 days phased implementation
Architecture Overview
NL Prompt → π0-3.5B (VLA Model) → Joint Control Commands → MuJoCo Simulator → Franka Panda Arm
Simulated RGB Camera Feed → π0 Visual Input (Closed Loop)7-Day Schedule
| Day | Task |
|---|---|
| D1 | Environment setup: CUDA, PyTorch, MuJoCo, simulation dependencies |
| D2 | Build Franka Panda tabletop scene in MuJoCo (cup, table, camera), manual control verification |
| D3 | BC-Z dataset download, filter cup-grasping subset, data preprocessing (image + action + text alignment) |
| D4 | π0-3.5B weights download, 4-bit quantization inference deployment, basic image→action pipeline |
| D5 | LoRA fine-tuning: train only LoRA adapters on BC-Z cup subset (memory-friendly, no full-parameter training) |
| D6 | Integration: real-time sim camera feed → π0 inference → motor commands → Franka execution |
| D7 | Debugging, evaluation, prompt optimization, iterative testing |
Key Technologies
- Simulation: MuJoCo 2.3.7 (free, open-source, MJCF Franka model)
- Dataset: BC-Z subset (filtered for cup grasping, 3-5GB from 32GB full dataset)
- Model: OpenPI π0-3.5B (Physical Intelligence open-source VLA, natively supports Franka)
- Fine-tuning: LoRA + 4-bit quantization (fits in 12GB VRAM)
- Pipeline: Real-time MuJoCo rendering → π0 inference → joint action → simulation step
Resources
- π0 Weights: huggingface.co/physical-intelligence/p0-3.5b
- BC-Z Dataset: huggingface.co/datasets/robotics/bc_z
- MuJoCo Franka Model: github.com/deepmind/mujoco_menagerie
- openpi Docs: github.com/Physical-Intelligence/openpi