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  "story": {
    "story_id": "mp-2026-10-25-011",
    "source_story_id": "tmp-story-cohelix-propeller-tracking",
    "edition_id": "mp-2026-10-25-morning-0107",
    "edition_url": "https://themachinepress.com/edition/2026-10-25",
    "position": 11,
    "story_type": "dispatch",
    "section": "robotics",
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    "headline": "Four Propellers Share One Moving Geometry",
    "slug": "four-propellers-share-one-moving-geometry",
    "dek": "An event-camera tracker estimates one homography across a quadrotor while keeping separate rotation states for each spinning propeller.",
    "summary": "An event-camera tracker estimates one homography across a quadrotor while keeping separate rotation states for each spinning propeller.",
    "body_text": "A moving event camera sees blade rotation mixed with camera motion, background events and half- or double-rate ambiguities. CoHelix assigns events to four coplanar propellers, updates each rotation state separately and lets accepted measurements from any propeller refine one shared projective geometry. The paper emphasizes lock—the fraction of time an estimate remains within two percent of synchronized ground truth—rather than mean error alone. On moving-camera recordings, CoHelix reached 62.9 percent lock versus 39.8 and 22.2 percent for two comparisons; on a private target-follower set it reached 95.9 percent. The private set and fixed initialization limit generalization, and the tracker does not prove safe flight control.",
    "why_it_matters": "An event-camera tracker estimates one homography across a quadrotor while keeping separate rotation states for each spinning propeller.",
    "limitations": [
      "The private set and fixed initialization limit generalization, and the tracker does not prove safe flight control."
    ],
    "importance": 8,
    "canonical_url": "https://themachinepress.com/story/mp-2026-10-25-011/four-propellers-share-one-moving-geometry",
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    "first_published_at": "2026-10-25T09:00:00.000-04:00",
    "modified_at": "2026-10-25T09:00:00.000-04:00",
    "content_status": "new",
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        "text": "An event-camera tracker estimates one homography across a quadrotor while keeping separate rotation states for each spinning propeller.",
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        "qualification": "The private set and fixed initialization limit generalization, and the tracker does not prove safe flight control."
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    "source_ids": [
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    "tags": [
      "event cameras",
      "quadrotors",
      "tracking",
      "projective geometry"
    ],
    "image_url": null,
    "corrections": []
  },
  "sources": [
    {
      "source_id": "source-2026-10-25-011",
      "title": "arXiv preprint 2610.31384, original v1",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2610.31384v1",
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      "source_type": "primary_research",
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      "published_at": "2026-10-22T10:52:37.000-04:00",
      "accessed_at": "2026-10-25T08:17:14.361-04:00",
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  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
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  "cite_this_report": {
    "title": "Four Propellers Share One Moving Geometry",
    "publisher": "The Machine Press",
    "published_at": "2026-10-25T09:00:00.000-04:00",
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