Whole body manipulation on a legged robot using dynamic balance

Patent metadata

Field	Value
Publication number	US-11667343-B2
Application number	US-201916433779-A
Country	US
Kind code	B2
Filing date	Jun 6, 2019
Priority date	Dec 13, 2016
Publication date	Jun 6, 2023
Grant date	Jun 6, 2023

Abstract

A robot system includes: an upper body section including one or more end-effectors; a lower body section including one or more legs; and an intermediate body section coupling the upper and lower body sections. An upper body control system operates at least one of the end-effectors. The intermediate body section experiences a first intermediate body linear force and/or moment based on an end-effector force acting on the at least one end-effector. A lower body control system operates the one or more legs. The one or more legs experience respective surface reaction forces. The intermediate body section experiences a second intermediate body linear force and/or moment based on the surface reaction forces. The lower body control system operates the one or more legs so that the second intermediate body linear force balances the first intermediate linear force and the second intermediate body moment balances the first intermediate body moment.

First claim

What is claimed is:

1. A robot system comprising: a body comprising:
an upper body section comprising a movable end-effector;
a lower body section comprising a leg configured to contact a surface; and
an intermediate body section coupling the upper body section and the lower body section; and
a control system implemented with a processor, the control system comprising:
an upper body control system configured to operate the movable end-effector, the movable end-effector experiencing a first force based on operation of the movable end-effector, and the intermediate body section experiencing at least one of a second force or a first moment based on the first force; and

a lower body control system configured to:
receive, from the upper body control system, information associated with the at least one of the second force or the first moment;
operate the leg based on the operation of the movable end-effector, the leg experiencing a third force from the surface based on operation of the leg, and the intermediate body section experiencing at least one of a fourth force or a second moment based on the third force; and
balance at least one of the fourth force to the second force or the second moment to the first moment to balance the body.

2. The robot system of claim 1 , wherein the upper body control system is further configured to identify the lower body section as a virtual link coupled to the intermediate body section.

3. The robot system of claim 1 , wherein:
the lower body control system is further configured to position the intermediate body section according to one or more first degrees of freedom based on the operation of the leg;
the upper body control system is further configured to position the intermediate body section according to one or more second degrees of freedom based on the operation of the movable end-effector; and
the upper body control system is constrained from positioning the intermediate body section according to the one or more first degrees of freedom.

4. The robot system according to claim 3 , wherein:
positioning the intermediate body section according to the one or more first degrees of freedom causes translation of the intermediate body section along a first axis and a second axis; and
positioning the intermediate body section according to the one or more second degrees of freedom causes rotation of the intermediate body section about at least three axes and causes translation of the intermediate body section along a third axis.

5. The robot system according to claim 1 , wherein:
the lower body section comprises two legs, and each leg includes a respective foot configured to contact the surface directly;
for a given position of each foot, the lower body control system is configured to determine whether the lower body control system can balance a respective fourth force to the second force or the second body moment to the first moment; and
in response to determining that the lower body control system cannot balance the respective fourth force to the second force or the second moment to the first moment, the lower body control system is configured to reposition at least one of the feet on the surface.

6. The robot system according to claim 5 , wherein the lower body control system is further configured to adjust the repositioning of the at least one of the feet according to a gait.

7. The robot system of claim 1 , wherein the lower body control system is further configured to operate the leg in response to the operation of the movable end-effector while the leg is moving according to a gait.

8. A robot system comprising: a body comprising:
an upper body section comprising a movable end-effector;
a lower body section comprising a leg configured to contact a surface; and
an intermediate body section coupling the upper body section and the lower body section; and
a control system implemented with a processor, the control system comprising:
an upper body control system configured to operate the upper body section, the intermediate body section experiencing at least one of a first force or a first moment based on operation of the upper body section; and
a lower body control system configured to operate the lower body section based on the operation of the upper body section, the intermediate body section experiencing at least one of a second force or a second moment based on operation of the lower body section,
wherein the lower body control system is configured to balance at least one of the second force to the first force or the second moment to the first moment, and
wherein the upper body control system is constrained from using a same one or more degrees of freedom to position the intermediate body section that the lower body control system uses to position the intermediate body section.

9. The robot system of claim 8 , wherein the upper body control system is further configured to communicate, to the lower body control system, information relating to the first force and the first moment.

10. The robot system of claim 8 , wherein the upper body control system is further configured to identify the lower body section as a virtual link coupled to the intermediate body section.

11. The robot system according to claim 8 , wherein:
the lower body control system is configured to position the intermediate body section according to one or more first degrees of freedom to cause translation of the intermediate body section along a first axis and a second axis; and
the upper body control system is configured to position the intermediate body section according to one or more second set of degrees of freedom to cause rotation of the intermediate body section about at least three axes and cause translation of the intermediate body section along a third axis.

12. The robot system according to claim 8 , wherein:
the lower body section comprises two legs, and each leg includes a respective foot configured to contact the surface directly;
for a given position of each foot, the lower body control system is configured to determine whether the lower body control system can balance a respective second force to the first force or the second moment to the first moment; and
in response to determining that the lower body control system cannot balance a respective second force to the first force or the second moment to the first moment, the lower body control system is configured to reposition at least one of the feet on the surface.

13. A robot system comprising: a body comprising:
an upper body section comprising a movable end-effector;
a lower body section comprising a leg configured to contact a surface, wherein the lower body section comprises two legs, and each leg includes a respective foot configured to contact the surface directly; and
an intermediate body section coupling the upper body section and the lower body section; and
a control system implemented with a processor, the control system comprising:
an upper body control system configured to operate the upper body section, the intermediate body section experiencing at least one of a first force or a first moment based on operation of the upper body section; and
a lower body control system configured to operate the lower body section in response to the operation of the upper body section, the intermediate body section experiencing at least one of a second force or a second moment based on operation of the lower body section,
wherein the lower body control system is configured to balance at least one of the second force to the first force or the second moment to the first moment wherein to balance at least one of the second force to the first force or the

Assignees

• Boston Dynamics Inc

Inventors

• Blankespoor Kevin
• Stephens Benjamin
• Hudson Nicolas
• Abe Yeuhi
• Barry Jennifer

Classifications

• B25J9/1633

  compliant, force, torque control, e.g. combined with position control · CPC title

• B25J9/162 Primary

  Mobile manipulator, movable base with manipulator arm mounted on it · CPC title

• G05B2219/40298

  Manipulator on vehicle, wheels, mobile · CPC title

• Y10S901/01

  Mobile robot · CPC title

• B62D57/032 Primary

  with alternately or sequentially lifted supporting base and legs; with alternately or sequentially lifted feet or skid (B62D57/024 takes precedence) · CPC title