Granted Patent B2

US 12,384,038 · App. 18/345,405 · Granted Aug 12, 2025

Inventors: Gabriel Nelson (Waltham, MA); Benjamin Stephens (Somerville, MA)

Assignee: Boston Dynamics, Inc.

B25J9/1682B25J5/00B25J9/1666B25J13/089B25J19/02B62D57/032Y10S901/01

Abstract

Claims (54)

1. A method comprising:

controlling, by data processing hardware of a legged robot, a first leg of the legged robot to move to a first touchdown location on a surface;

obtaining, by the data processing hardware, a first measurement indicating a distance between a center of mass of the legged robot and the first leg when the first leg touches down at the first touchdown location;

controlling, by the data processing hardware, the first leg to rise from the surface;

obtaining, by the data processing hardware, a second measurement indicating a distance between the center of mass of the legged robot and the first leg when the first leg is raised from the surface;

determining, by the data processing hardware, a second touchdown location on the surface for a second leg of the legged robot based on the first measurement and the second measurement; and

controlling, by the data processing hardware, the second leg of the legged robot to move to the second touchdown location on the surface.

2. The method of claim 1 , further comprising:

determining, by the data processing hardware, an estimated velocity of the legged robot based on a difference between the first measurement and the second measurement;

determining, by the data processing hardware, an estimated acceleration of the legged robot based on a sum of the first measurement and the second measurement; and

determining, by the data processing hardware, the second touchdown location based on the estimated velocity and the estimated acceleration.

3. The method of claim 2 , wherein determining the second touchdown location based on the estimated velocity and the estimated acceleration comprises determining, by the data processing hardware, a linear combination of the estimated velocity and the estimated acceleration.

4. The method of claim 2 , further comprising determining, by the data processing hardware, an expected path of the legged robot based on the estimated velocity and the estimated acceleration.

5. The method of claim 4 , further comprising:

detecting, by the data processing hardware, an expected collision of the legged robot with an object based on the expected path; and

adjusting, by the data processing hardware, the second touchdown location to avoid the expected collision.

6. The method of claim 1 , wherein a first height of the surface at the first touchdown location is different from a second height of the surface at the second touchdown location.

7. The method of claim 1 , further comprising controlling, by the data processing hardware, a body of the legged robot to move over the first leg when the first leg is touched down at the first touchdown location.

8. The method of claim 1 , further comprising:

detecting, by the data processing hardware, a slip of the first leg; and

adjusting, by the data processing hardware, the second touchdown location to account for the slip.

9. The method of claim 1 , further comprising determining, by the data processing hardware, the second touchdown location based on a damping ratio indicating a rate to suppress a perturbation arising from an external force.

10. The method of claim 1 , further comprising:

receiving, by the data processing hardware, a command indicating a desired change of velocity for the legged robot; and

determining, by the data processing hardware, the second touchdown location based on the desired change of velocity.

11. A legged robot comprising:

a body;

a plurality of legs coupled to the body, the plurality of legs comprising a first leg and a second leg;

data processing hardware; and

memory hardware in communication with the data processing hardware, the memory hardware storing instructions that when executed on the data processing hardware cause the data processing hardware to perform operations comprising:

controlling the first leg to move to a first touchdown location on a surface;

obtaining a first measurement indicating a distance between a center of mass of the legged robot and the first leg when the first leg touches down at the first touchdown location;

controlling the first leg to rise from the surface;

obtaining a second measurement indicating a distance between the center of mass of the legged robot and the first leg when the first leg is raised from the surface;

determining a second touchdown location on the surface for a second leg of the legged robot based on the first measurement and the second measurement; and

controlling the second leg of the legged robot to move to the second touchdown location on the surface.

12. The legged robot of claim 11 , wherein the operations further comprise:

determining an estimated velocity of the legged robot based on a difference between the first measurement and the second measurement;

determining an estimated acceleration of the legged robot based on a sum of the first measurement and the second measurement; and

determining the second touchdown location based on the estimated velocity and the estimated acceleration.

13. The legged robot of claim 12 , wherein determining the second touchdown location based on the estimated velocity and the estimated acceleration comprises determining a linear combination of the estimated velocity and the estimated acceleration.

14. The legged robot of claim 12 , wherein the operations further comprise determining an expected path of the legged robot based on the estimated velocity and the estimated acceleration.

15. The legged robot of claim 14 , wherein the operations further comprise:

detecting an expected collision of the legged robot with an object based on the expected path; and

adjusting the second touchdown location to avoid the expected collision.

16. The legged robot of claim 11 , wherein a first height of the surface at the first touchdown location is different from a second height of the surface at the second touchdown location.

17. The legged robot of claim 11 , wherein the operations further comprise controlling the body to move over the first leg when the first leg is touched down at the first touchdown location.

18. The legged robot of claim 11 , wherein the operations further comprise:

detecting a slip of the first leg; and

adjusting the second touchdown location to account for the slip.

19. The legged robot of claim 11 , wherein the operations further comprise determining the second touchdown location based on a damping ratio indicating a rate to suppress a perturbation arising from an external force.

20. The legged robot of claim 11 , wherein the operations further comprise:

receiving a command indicating a desired change of velocity for the legged robot; and

determining the second touchdown location based on the desired change of velocity.

Continuity (5)

References Cited (180)