Granted Patent B2

US 12,552,011 · App. 18/526,504 · Granted Feb 17, 2026

Inventors: Matthew Lawrence Elwin (Chicago, IL); Billie Jane Strong (Evanston, IL); Kevin M. Lynch (Evanston, IL); Randy A. Freeman (Mount Prospect, IL)

Assignee: Northwestern University

B25J5/007B25J9/1664B25J13/085B25J15/0019

Abstract

Claims (26)

1 . A robot system comprising:

a plurality of mobile manipulator robots, wherein each mobile manipulator robot includes:

a mobile robot base;

a robot manipulator mounted to the mobile robot base, wherein the robot manipulator includes a Delta robot, and wherein each actuated joint of each Delta robot is driven by a series-elastic actuator; and

one or more computers in communication with the mobile robot base and the robot manipulator, wherein the one or more computers are configured to simultaneously:

coordinate motion control of the mobile robot base and force control of the robot manipulator to manipulate a payload in cooperation with other mobile manipulator robots of the plurality; and

collaborate with zero, one, or a plurality of human users that are in contact with the payload.

2 . The robot system of claim 1 , wherein each series-elastic actuator includes a pair of antagonistic springs connecting an actuator-driven yoke to a link of the Delta manipulator.

3 . The robot system of claim 1 , wherein an encoder-instrumented unactuated gimbal with three degrees of freedom is mounted to the Delta robot.

4 . The robot system of claim 1 , wherein each mobile robot base comprises a wheeled robot base.

5 . The robot system of claim 4 , wherein the wheeled robot base comprises an omnidirectional wheeled robot base.

6 . The robot system of claim 1 , wherein the mobile manipulator robots communicate wirelessly with each other or a central control station.

7 . The robot system of claim 1 , wherein each mobile robot base is configured to sense its position and orientation.

8 . A robot manipulator comprising:

a Delta robot, wherein each actuated joint of the Delta robot is driven by an actuator incorporating one or more spring elements;

one or more computers in communication with the Delta robot and configured to measure and control translational forces in a frame fixed to a moving output platform of the Delta robot; and

an encoder-instrumented unactuated gimbal with three degrees of freedom mounted to the moving output platform of the Delta robot.

9 . The robot manipulator of claim 8 , further comprising a mobile robot base to which the Delta robot is mounted.

10 . The robot manipulator of claim 9 , wherein the mobile robot base is an omnidirectional wheeled mobile robot.

11 . A method of controlling a plurality of mobile manipulator robots, the method comprising simultaneously achieving, by a computing system, a desired linear force in a frame fixed to an output platform of a Delta robot while driving a mobile base to keep the output platform of the Delta robot as close as possible to a center of a workspace in which the Delta robot is operating.

12 . The method of claim 11 , further comprising determining, by the computing system, forces to be applied to a payload by the plurality of mobile manipulator robots collectively to cause the payload to feel weightless to one or more human users contacting the payload.

13 . The method of claim 11 , further comprising collectively estimating, by the mobile manipulator robots, a mass and one or more inertial properties of a payload that is to be manipulated.

14 . The method of claim 11 , wherein the computing system comprises a central control station.

15 . The method of claim 11 , further comprising determining, by one or more sensors and the computing system, a position and an orientation of the mobile base.

16 . The method of claim 15 , wherein the encoder-instrumented unactuated gimbal has three degrees of freedom.

17 . The method of claim 11 , wherein each actuated joint of each Delta robot is driven by a series-elastic actuator.

Assignments (1)

Continuity (2)

References Cited (40)