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    "story_id": "mp-2026-10-01-011",
    "source_story_id": "tmp-story-vla-moving-hazard-safety-filter",
    "edition_id": "mp-2026-10-01-morning-0084",
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    "position": 11,
    "story_type": "dispatch",
    "section": "safety-security",
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    "headline": "A Safety Filter Watched the Whole Robot Arm",
    "slug": "a-safety-filter-watched-the-whole-robot-arm",
    "dek": "Five ellipsoids guarded the gripper, wrist and forearm while optical flow tracked a moving hazard.",
    "summary": "Five ellipsoids guarded the gripper, wrist and forearm while optical flow tracked a moving hazard.",
    "body_text": "The training-free shield wraps five ellipsoids around a robot arm and filters commanded motion through one barrier program. A keep-out ellipsoid is fitted from RGB-D at reset and moved with sparse optical flow, avoiding repeated detection. Across simulation, collision fell from 65.62% to 27.27%; on a physical SO-101 arm, hazards were touched in 3 of 16 shielded episodes versus 11 of 16 unshielded ones. The remaining contacts show risk reduction, not complete protection.",
    "why_it_matters": "Five ellipsoids guarded the gripper, wrist and forearm while optical flow tracked a moving hazard.",
    "limitations": [
      "The remaining contacts show risk reduction, not complete protection."
    ],
    "importance": 8,
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    "first_published_at": "2026-10-01T09:00:00.000-04:00",
    "modified_at": "2026-10-01T09:00:00.000-04:00",
    "content_status": "new",
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        "text": "Five ellipsoids guarded the gripper, wrist and forearm while optical flow tracked a moving hazard.",
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        "qualification": "The remaining contacts show risk reduction, not complete protection."
      }
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    "source_ids": [
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    "tags": [
      "robot safety",
      "vision-language-action",
      "moving hazards"
    ],
    "image_url": null,
    "corrections": []
  },
  "sources": [
    {
      "source_id": "source-2026-10-01-011",
      "title": "arXiv preprint 2609.40007",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2609.40007",
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      "published_at": "2026-09-30T11:49:49.000-04:00",
      "accessed_at": "2026-10-01T08:18:00.000-04:00",
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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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    "title": "A Safety Filter Watched the Whole Robot Arm",
    "publisher": "The Machine Press",
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