Trajectory deduplication (dedup/)
Near-duplicate removal over the 94,030-episode DROID LeRobot export (94,006 episodes with valid kinematic signals were assessed; 24 episodes with degenerate signals are kept by default). A duplicate is a near-identical re-recording of the same task; different tasks — including paraphrases resolved to different tasks, object swaps, or the same task done in a different place — are treated as diversity and never merged.
Method
- Merge task phrasings — instructions are canonicalised (synonym folding
for verbs/objects, prepositions to
<p>, articles dropped, order and attributes preserved): 31,304 distinct instruction strings → 28,458 task families. Episodes without an instruction (task_index 31051, 43,133 episodes) are grouped by their labeled verb+object chain instead. - Trajectory signature — keyframes = gripper open/close events +
end-effector deceleration points; the keyframe EE positions are
start-centred and arc-length-resampled to K=8 points → a 24-number
signature per episode (see
descriptors.npz). - Duplicate rule — same family AND mean per-point Euclidean distance < 3 cm AND identical gripper open/close pattern. Leader clustering: every member is within 3 cm of its cluster leader, so transitive chains cannot glue far-apart trajectories together.
- Keep TWO per cluster (
DEDUP_KEEP=2) — the cluster medoid plus the member farthest from the medoid (greedy max-min), retaining the cluster's residual spread. Clusters of size 2 are kept whole.
Results (eps = 3 cm, keep = 2)
| metric | value |
|---|---|
| episodes assessed | 94,006 |
| episodes in multi-episode clusters | 8,656 (9.21%) |
| multi-episode clusters | 2,260 (largest: 539 frozen no-instruction episodes) |
| episodes kept (hard dedup) | 89,870 |
| episodes removed | 4,136 (4.40%) |
A stricter keep-one-per-cluster variant is archived as
report_keep1.json / keep_list_keep1.txt (87,610 kept / 6,396 removed).
Files
episode_weights.jsonl— one line per episode:{episode_id, task_index, cluster_id, cluster_size, weight, representative}.representative: true⇔ kept by hard dedup (2 per multi-cluster). Soft weights: representatives 1.0, other members 1/cluster_size — use them to reweigh instead of dropping.seg_weights.jsonl—{seg_id, weight}for all 588,151 annotated segments (weight inherited from the episode; joinsannotations/segments.jsonl).keep_list.txt— episode_id per line, the 89,870 kept episodes.report.json— the stats table above.descriptors.npz—eids(94,006),tasks,descs(94,006×8×3 float32, metres, start-relative),grips(gripper pattern strings): everything needed to re-run clustering at a different eps / keep policy.keep_list_keep1.txt,report_keep1.json— archived keep-1 variant.