{
  "annotation_id": "02f63f4f-b76c-4f01-92b1-d758b69dc6e4",
  "date_created": "2026-03-02T18:01:21.745000Z",
  "date_modified": "2026-03-02T18:01:21.745000Z",
  "file_hash": "fe982b1aceb61e91d28a64f0cb86d57d00e58ef2ec8091b65bb39742cc2d4487",
  "private": false,
  "record": {
    "abstract": "We built a simple two-leg toy that can walk stably with no control system. It\nwalks downhill powered only by gravity. It seems to be the first McGeer-like\npassive-dynamic walker that is statically unstable in all standing positions,\nyet is stable in motion. It is one of few known mechanical devices that are\nstable near a statically unstable configuration but do not depend on spinning\nparts. Its design is loosely based on simulations which do not predict its\nobserved stability. Its motion highlights the possible role of uncontrolled\nnonholonomic mechanics in balance.",
    "arxiv_id": "physics/9711006",
    "authors": [
      "Michael J. Coleman",
      "Andy Ruina"
    ],
    "categories": [
      "physics.class-ph",
      "physics.med-ph"
    ],
    "title": "An Uncontrolled Toy That Can Walk But Cannot Stand Still",
    "url": "https://arxiv.org/abs/physics/9711006"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "93f3449f-928a-41ba-bb09-ef9fe614c1ba",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}