Leg configuration for spring-mass legged locomotion

{
  "publication_number": "US10189519B2",
  "country": "US",
  "kind": "B2",
  "title": "Leg configuration for spring-mass legged locomotion",
  "abstract": "Devices and methods for legged locomotion, including a robotic leg for spring-mass legged locomotion incorporating passive dynamics.",
  "claims": [
    "1. A robot for legged locomotion, comprising: a body; a leg having first, second, and third links, with the first and second links pivotally mounted to one another and with the second and third links pivotally mounted to one another, the first link having opposing first and second ends with the first end pivotally mounted to the body; a first actuator mounted at the body and configured to rotate the first link about the first end of the first link; a second actuator mounted at the first link and configured to rotate the second link relative to the first link, wherein the first and second actuators are operable to swing the leg and extend/retract the leg along a leg length direction; and a first leg spring disposed in series between the first link and the third link, and a second leg spring operably connected in series between the second actuator and the second link, the leg springs configured to store energy therein during a first portion of a stance and configured to recover the stored energy during a second portion of the stance to provide passive dynamics for locomotion.",
    "2. The robot of claim 1, comprising a gimbal actuator operably connected between the first link and the body.",
    "3. The robot of claim 2, wherein at least one of the first actuator, second actuator, and gimbal actuator includes a cycloid transmission.",
    "4. The robot of claim 2, wherein at least one of the first actuator, second actuator, and gimbal actuator includes a motor.",
    "5. The robot of claim 1, comprising two gimbal actuators operably connected between the first link and the body, the gimbal actuators each having an axis of rotation which axes are not oriented parallel to one another.",
    "6. The robot of claim 1, comprising two gimbal actuators operably connected between the first link and the body, the gimbal actuators each having an axis of rotation which axes are oriented perpendicular to one another.",
    "7. The robot of claim 6, wherein the axes of the two gimbal actuators are each oriented orthogonal to an axis of rotation of the first actuator.",
    "8. The robot of claim 1, comprising a first rotational element mounted at the body, the first actuator and rotational element operably connected such that the first actuator is configured to rotate the first rotational element to rotate the first link about the first end of the first link.",
    "9. The robot of claim 8, comprising a second rotational element mounted at the first link, the second actuator and second rotational element operably connected such that the second actuator is configured to rotate the second rotational element to rotate the second link relative to the first link.",
    "10. The robot of claim 9, comprising a cable pulley transmission operably connected between at least one of: (a) the first rotational element and the first actuator, and (b) the second rotational element and the second actuator.",
    "11. The robot of claim 9, comprising a cycloid transmission operably connected between at least one of: (a) the first rotational element and the first actuator, and (b) the second rotational element and the second actuator.",
    "12. The robot of claim 9, wherein the second leg spring is disposed in series between the second link and the second rotational element.",
    "13. The robot of claim 9, comprising a transmission operably connected between the first and second rotational elements, the transmission configured to transmit rotational movement of the first rotational element to the second rotational element.",
    "14. The robot of claim 9, wherein the second rotational element is disposed between the first and second links and attaches the first link to the second link.",
    "15. The robot of claim 9, wherein the second rotational element is mounted at the second end of the first link.",
    "16. The robot of claim 9, wherein the first rotational element is disposed between the body and first link and attaches the first link to the body.",
    "17. The robot of claim 9, wherein the first rotational element is mounted at the body.",
    "18. The robot of claim 1, wherein the first actuator is configured to rotate an angle of the leg.",
    "19. The robot of claim 1, wherein the second actuator is configured to control the leg length of the leg.",
    "20. The robot of claim 1, wherein the leg includes a transmission disposed between the first link and the third link.",
    "21. The robot of claim 20, wherein the transmission includes a link.",
    "22. The robot of claim 1, wherein the second and third links have respective longitudinal axes, and the second and/or third links are rotatable about their respective longitudinal axes to provide yaw and adduction/abduction of the leg.",
    "23. The robot of claim 1, comprising a transmission operably connected between the first and third links, the transmission configured to transmit rotational movement of the first link to the third link."
  ],
  "description_excerpt": "This invention was made with government support under contract number W91CRB-11-1-0002 awarded by the Defense Advanced Research Projects Agency (DARPA). The government has certain rights in the invention.\n\nThe present invention relates generally to devices and methods for legged locomotion, including a robotic leg for spring-mass legged locomotion incorporating passive dynamics.\n\nHumans and other animals have the remarkable ability to negotiate an unknown and changing environment, not only without falling, but also with a level of efficiency currently unmatched in existing robotic systems. Literature suggests that a large portion of this agility may be due to the natural behavior of the animal's body in addition to neurological feedback control. Morphology and materials of limbs (their mass, elasticity of tendons, lever arms between joints, etc.) can enable efficient and immediate feedback control and stabilization at the hardware level. Using this hardware-in-the-loop control premise, natural looking walking and running gaits can emerge from the “natural” (“free” or “passive”) dynamics of the mechanism.\n\nPassive dynamics exist for any physical system, whether premeditated or not, and whether favorable or detrimental to the task at hand. For highly dynamic behaviors, with large accelerations, impacts, and/or energy transfers, passive dynamics can significantly affect the performance.",
  "cpc": [
    "B62D 57/032",
    "B62D 57/02",
    "Y10S 901/01"
  ],
  "ipc": [
    "B62D 57/032",
    "B62D 57/02"
  ],
  "assignees": [
    "Oregon State University"
  ],
  "inventors": [
    "Jonathan Hurst",
    "Mikhail Sobiegraj Jones",
    "Andrew Martin Abate"
  ],
  "filing_date": "2016-05-27",
  "publication_date": "2019-01-29",
  "grant_date": "2019-01-29",
  "priority_date": "2015-05-29",
  "application_number": "US-201615166517-A",
  "family_id": "57397972",
  "cited_by_count": 25,
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}