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    "story_id": "mp-2026-10-18-009",
    "source_story_id": "tmp-story-lettuce-path-safe-robot",
    "edition_id": "mp-2026-10-18-morning-0100",
    "edition_url": "https://themachinepress.com/edition/2026-10-18",
    "position": 9,
    "story_type": "dispatch",
    "section": "robotics",
    "editorial_classification": "editorial",
    "headline": "The Lettuce Harvester Learns That Reaching Is Not Enough",
    "slug": "the-lettuce-harvester-learns-that-reaching-is-not-enough",
    "dek": "A sim-trained policy protects the approach corridor, transfers to a UR10e without real-world fine-tuning and completes 86.1 percent of harvest attempts.",
    "summary": "A sim-trained policy protects the approach corridor, transfers to a UR10e without real-world fine-tuning and completes 86.1 percent of harvest attempts.",
    "body_text": "A robot can hit the target point and still damage a crop on the way in. PSA-PPO adds corridor-aware constraints, trajectory-history safety encoding and task-specific success criteria to a target-conditioned reaching policy trained entirely in Isaac Lab. On 150 scheduled physical targets, it reached 94.7 percent, beating three classical planners while reducing final-approach jerk. Integrated with RGB-D perception and an end effector, the system reached 94.4 percent of targets and completed 86.1 percent of 144 lettuce harvest attempts. The results come from a controlled hydroponic setup and do not establish commercial farm readiness.",
    "why_it_matters": "A sim-trained policy protects the approach corridor, transfers to a UR10e without real-world fine-tuning and completes 86.1 percent of harvest attempts.",
    "limitations": [
      "The results come from a controlled hydroponic setup and do not establish commercial farm readiness."
    ],
    "importance": 8,
    "canonical_url": "https://themachinepress.com/story/mp-2026-10-18-009/the-lettuce-harvester-learns-that-reaching-is-not-enough",
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    "first_published_at": "2026-10-18T09:00:00.000-04:00",
    "modified_at": "2026-10-18T09:00:00.000-04:00",
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        "text": "A sim-trained policy protects the approach corridor, transfers to a UR10e without real-world fine-tuning and completes 86.1 percent of harvest attempts.",
        "source_ids": [
          "source-2026-10-18-009"
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        "qualification": "The results come from a controlled hydroponic setup and do not establish commercial farm readiness."
      }
    ],
    "source_ids": [
      "source-2026-10-18-009"
    ],
    "tags": [
      "robotics",
      "agriculture",
      "sim-to-real"
    ],
    "image_url": null,
    "corrections": []
  },
  "sources": [
    {
      "source_id": "source-2026-10-18-009",
      "title": "arXiv preprint 2610.22337, original v1",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2610.22337v1",
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      "source_type": "primary_research",
      "is_primary_source": true,
      "published_at": "2026-10-15T13:54:16.000-04:00",
      "accessed_at": "2026-10-18T08:23:52.920-04:00",
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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": "The Lettuce Harvester Learns That Reaching Is Not Enough",
    "publisher": "The Machine Press",
    "published_at": "2026-10-18T09:00:00.000-04:00",
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