--- license: apache-2.0 task_categories: - robotics tags: - robotics - retargeting - agilex-piper - lerobot --- # piper-retargeted Human demonstrations retargeted to an **AgileX Piper** arm with the Fidelity Dynamics dt-pipeline (stage 6). Two datasets, one repo. | archive | size | clips | frames | source | |---|---|---|---|---| | `piper_ego_retargeted.tar` | 2.2 GB | 1,574 | 164,601 | EgoDex-derived egocentric pick-and-place (`ego_filtered`, LeRobot v3.0, 30 tasks) | | `piper_stera_plate_retargeted.tar` | 332 MB | 226 | 30,584 | stera-10m plate handling (`plate200_pp`) | Each archive is **self-contained**: the observation video sits in the same clip directory as the trajectory it belongs to, so there is nothing to join. ## Layout ``` /clips//observation.mp4 # RGB observation for this clip /clips//retargeted.hdf5 # trajectories + per-frame IK error /clips//report.json # per-clip M1–M6 record, QA grades /manifest.json # aggregate stats + one row per clip /README.md ``` Video and trajectory are 1:1 per clip and share the clip's frame count and 30 fps timebase. Archives are uncompressed `.tar` — the MP4s are already compressed, so gzip would cost time and save nothing. `retargeted.hdf5`: | key | shape | meaning | |---|---|---| | `joint_positions` | (T, 14) | arms in R, L order — 6 joints + 1 gripper each | | `ik_errors_R` / `_L` | (T,) | per-frame IK position error, metres | | `base_R` / `_L` | (3,) | base placement chosen by BPP | | `timestamps` | (T,) | seconds, 30 fps | Attributes carry `joint_names`, `active_arms`, `parked_arms`, `arm_mode`, `n_arms`, `fps` and the M4/QA records. ## Robot `agilex_piper_bimanual`. Stage 6 loads one single-arm MJCF and drives it once per arm with its own base placement, so "bimanual" needs no two-arm model. Joints `joint1..joint6` plus jaw `joint7` (`joint8` is coupled `= -joint7`). The TCP is the `grasp_frame` fingertip midpoint, not `Link6`. Workspace placement used `WORKSPACE_CENTER_MODE=capmap`: the centre is the reachability-index-weighted centroid of this arm's own pose-reachable voxels (`[0.034, 0.000, 0.208]` over 18,479 voxels), not a reference robot's vector rescaled. Scale 0.8811 (reach ratio 1.037; Piper 0.897 m vs reference 0.865 m). ## Quality | | ego | stera | |---|---|---| | FK error (worst active arm) | mean **4.48 cm**, median 3.87, p90 7.63 | mean **10.53 cm**, median 7.20, p90 24.66 | | saturation | mean 0.426 | mean 0.506 | | QA PASS / WARN / FAIL | 262 / 1012 / 300 | 19 / 111 / 96 | | dominant FAIL cause | saturation (331) | saturation (89), self-collision (18) | **Filter, don't discard.** `qa_verdict` gates on the worst single arm joint's fraction of frames pinned at a limit, so one saturated DOF fails a clip whose tracking is otherwise good. `manifest.json` carries per-clip `ik_mean_cm` and `saturation` if you would rather threshold yourself. The stera set is substantially the weaker of the two. ### Per-dataset notes **ego** — both arms are active on every clip, but not equally busy: the right arm travels a median 1.00 m per clip against the left's 0.025 m and carries the error (4.25 vs 0.44 cm). A near-static arm can still saturate by resting against a limit; 139 of the 300 FAILs are left-arm. **stera** — single-arm (`--arm right`); the left arm is a constant park pose carrying no signal, so drop columns 7–13 for single-arm training. **29 of the 255 selected clips are absent** because the human demonstrator used their left hand, dropping the right below the 50% tracking threshold; they are listed in `manifest.json` under `skipped_clips`. Because M3.5 re-solves the moving arm to avoid the parked one, 18 clips FAIL on `selfcol` for a collision that will not exist once the left arm is dropped. ## Known limit About 73% of Piper's joint saturation is **wrist-driven** (joint4 and joint5; joint5's range is only ±1.22 rad, the tightest on the arm). A workspace re-placement cannot fix an orientation the wrist cannot reach, which is why the teleop-supervised refit is disabled for these runs — measured, it accepted 2 of 150 clips. The remaining lever is orientation-side, not placement.