| --- |
| license: apache-2.0 |
| tags: |
| - robotics |
| - vla |
| - openpi |
| - pi0 |
| - lerobot |
| - manipulation |
| - bimanual |
| library_name: openpi |
| pipeline_tag: robotics |
| --- |
| |
| # openpi_lab — real-robot π₀ checkpoints + the datasets they were trained on |
| |
| Two robots, each with its trained π₀ weights and the exact LeRobot dataset behind them. |
| |
| **G2** is the main release — trained, validated on hardware in four stages, and it completes |
| its task closed-loop from live camera observations. |
| **Piper** is a **reference example**: a second robot with a different arm count, action space |
| and control rate, provided so the pipeline can be followed on a contrasting setup. It ships |
| the checkpoints and data only; no evaluation results are claimed for it. |
| |
| ``` |
| g2/model/ π₀, 30k steps g2/dataset/ 58 ep / 48,332 frames / 10 Hz |
| piper/model/pi0/ π₀, 30k steps piper/dataset/ 125 ep / 71,702 frames / 30 Hz |
| piper/model/pi05/ π₀.₅, 30k steps |
| ``` |
| |
| | | **G2** | **Piper** | |
| |---|---|---| |
| | Robot | AgiBot G2, **dual** 7-DOF arm | AgileX Piper, **single** 6-DOF arm | |
| | Action / state | 16-D `[L_j1..7, L_grip, R_j1..7, R_grip]` | 7-D `[j1..j6, gripper]` | |
| | Action space | absolute joint rad + boolean gripper | joint **delta** from episode start + absolute gripper (m) | |
| | Cameras | head + hand_left + hand_right | head + hand | |
| | Control rate | **10 Hz** | **30 Hz** | |
| | Chunk | 50 | 16 | |
| | Tasks | 1 (`Make a yogurt bowl with cereal and fruit.`) | 4 (pen→cup, carrot→bowl, blocks→drawer, stack bowls) | |
| |
| ## Download |
| |
| ```bash |
| hf download siyuhsu/openpi_lab --include "g2/model/*" --local-dir ./g2_ckpt |
| hf download siyuhsu/openpi_lab --include "piper/model/pi0/*" --local-dir ./piper_pi0 |
| hf download siyuhsu/openpi_lab --include "g2/dataset/*" --local-dir ./g2_data |
| ``` |
| |
| ## Serving |
| |
| ```bash |
| # G2 |
| python examples/g2_dualarm/g2_serve_openpi.py --config pi0_g2_dualarm \ |
| --ckpt-dir ./g2_ckpt/g2/model --port 8000 |
| # Piper |
| python examples/piper/code/piper_serve_openpi.py --config pi0_piper_4task \ |
| --ckpt-dir ./piper_pi0/piper/model/pi0 --port 8000 |
| ``` |
| |
| Each server publishes its deployment contract in the connect-time metadata |
| (`action_chunk_size`, `action_rate_hz`, `robot_servo_hz`, `action_space`, `reset_pose`). |
| |
| > ⚠️ **Advance the action chunk at the DATASET rate, not the servo rate.** G2 is 10 Hz, |
| > Piper is 30 Hz. Actions are absolute (G2) or delta-from-start (Piper) joint targets; |
| > stepping G2's chunk at 30 Hz would execute it 3× too fast. |
| |
| ## Things that will bite you |
| |
| * **G2 gripper polarity is inverted between dataset and wire.** In the dataset `1.0` = OPEN, |
| `0.0` = CLOSED — the raw field is called `gripper_closed` and **the name is backwards** |
| relative to the physical behaviour. Verified from physical semantics: in episode 27 the |
| right gripper dim flips `1.0 → 0.0` at step 54, exactly as the arm reaches its deepest |
| point (the grasp). On that robot's DDS tool wire the convention is the opposite again. |
| Confirm your own wire convention before driving hardware. |
| * **G2's right gripper position sensor is dead** (constant 0.2173 in all 60 episodes), so |
| both gripper dims come from the *command* boolean, not a sensor. |
| * **G2 `_rs10` = resampled to a uniform 10 Hz grid.** Raw recordings are badly jittered — |
| but the cause is the on-robot **disk writer**, not the cameras or the control loop |
| (control runs at a steady 29.5–29.9 Hz; 60–65% of frames never reach disk). Naive |
| contiguous re-indexing distorts episode duration by −18%…+35%; resampling is +0.06%. |
| * **Do not JPEG-compress observations to save bandwidth.** Measured on the G2 checkpoint, |
| q92/q85 flips the *gripper decision* outright (|Δ| = 1.007 on a boolean dim, 3 of 6 |
| trials) while joint dims move only ~2°. Mean error hides this completely. |
| * **These policies are stochastic** (flow matching): identical input gives joint outputs |
| differing by ~1.2°. Repeated inference is not a determinism check. |
| * Piper's `action` is the recorded teleop target and **leads the state by ~3 frames**; |
| G2's satisfies `action[t] == state[t+1]` exactly. Do not assume one convention for both. |
| |
| ## Scope |
| |
| Single scene per task, 58 (G2) / 125 (Piper) demonstrations. Expect brittleness outside the |
| recorded prop layout. |
| |
| ## Code |
| |
| `examples/g2_dualarm/` and `examples/piper/` in the accompanying openpi fork, including the |
| real-robot clients, the staged validation tooling and the hardware-verification scripts. |
| |
