Kinematic design for robotic arm

Patent metadata

Field	Value
Publication number	US-9827678-B1
Application number	US-201615155388-A
Country	US
Kind code	B1
Filing date	May 16, 2016
Priority date	May 16, 2016
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

An example robotic arm includes a base linkage and a first end effector connected to a second end of the base linkage through a first rotational joint. The robotic arm additionally includes a control arm. The control arm includes a first linkage and a second linkage, each having a first end and a second end. The first end of the first linkage is connected to the second end of the base linkage through a second rotational joint. The first end of the second linkage is connected to the second end of the first linkage through a third rotational joint. The control arm also includes a second end effector connected to the second end of the second linkage through a fourth rotational joint. The first, second, third, and fourth rotational joints are configured to rotate in or parallel to a first plane.

First claim

What is claimed is:

1. A robotic arm comprising:
a base linkage having a first end and a second end;
a first end effector connected to the second end of the base linkage through a first rotational joint configured to allow the first end effector to rotate in a first plane; and
a control arm comprising:
a first linkage having a first end and a second end, the first end of the first linkage connected to the second end of the base linkage through a second rotational joint configured to allow the first linkage to rotate in or parallel to the first plane;
a second linkage having a first end and a second end, the first end of the second linkage connected to the second end of the first linkage through a third rotational joint configured to allow the second linkage to rotate in or parallel to the first plane; and
a second end effector connected to the second end of the second linkage through a fourth rotational joint configured to allow the second end effector to rotate in or parallel to the first plane.

2. The robotic arm of claim 1 , wherein at least one of the first actuated rotational joint, the second actuated rotational joint, the third actuated rotational joint, and the fourth actuated rotational joint is actuated by a harmonic drive mounted within the joint.

3. The robotic arm of claim 1 , further comprising a control system configured to:
provide instructions to actuate the first rotational joint to rotate the first end effector to a first orientation;
provide instructions to actuate the second rotational joint to rotate the control arm to a second orientation;
provide instructions to actuate the third rotational joint to align the second end effector with the first end effector based on the first orientation and the second orientation; and
provide instructions to actuate the fourth rotational joint to operate the second end effector in coordination with the first end effector.

4. The robotic arm of claim 1 , wherein:
the control arm is offset from the base linkage in a direction perpendicular to the first plane by a first distance to allow the robotic arm to fold into a compact form, wherein folding into a compact form comprises:
positioning the first linkage parallel to the base linkage such that the second end of the second linkage is positioned adjacent to the first end of the base linkage; and
positioning the second linkage parallel to the base linkage and the first linkage such that the second end of the second linkage is positioned adjacent to the first end of the first linkage and the second end of the base linkage; and
the robotic arm is controlled by a control system configured to provide instructions to cause the robotic arm to fold into the compact form.

5. The robotic arm of claim 1 , wherein the first end of the base linkage is connected to a support base through a fifth actuated joint configured to move the base linkage with at least one degree of freedom.

6. The robotic arm of claim 5 , wherein the robotic arm is controlled by a control system configured to:
provide instructions to cause the control arm to move the second end effector to grasp an object between the second end effector and the first end effector by pressing the object against the first end effector using the second end effector;
provide instructions to cause the base linkage to move the object grasped between the second end effector and the first end effector to a drop-off location by causing the fifth actuated joint to move the base linkage with the at least one degree of freedom; and
provide instructions to cause the control arm to move the second end effector to release, at the drop-off location, the object grasped between the second end effector and the first end effector.

7. The robotic arm of claim 5 , wherein the robotic arm is controlled by a control system configured to:
provide instructions to actuate the first rotational joint to rotate the first end effector to a first orientation;
provide instructions to actuate the second rotational joint to rotate the control arm to a second orientation;
provide instructions to actuate the third rotational joint to align the second end effector with the first end effector based on the first orientation and the second orientation; and
provide instructions to actuate the fourth rotational joint to operate the second end effector in coordination with the first end effector;
provide instructions to actuate the fifth actuated joint to move the base linkage with the at least one degree of freedom;
provide instructions to maintain a constant pitch of the first end effector by adjusting the orientation of the first end effector as the base linkage is moved with the at least one degree of freedom; and
provide instructions to maintain the second end effector in a constant position in relation to the first end effector by adjusting the orientation of the control arm in response to adjustments in the orientation of the first end effector.

8. The robotic arm of claim 5 , wherein the robotic arm is controlled by a control system configured to:
provide instructions to cause the control arm to move the second end effector to push an object onto the first end effector;
provide instructions to cause the base linkage to move the object disposed on the first end effector to a drop-off location by causing the fifth actuated joint to move the base linkage with the at least one degree of freedom; and
provide instructions to cause the first end effector to drop off, at the drop-off location, the object disposed on the first end effector.

9. The robotic arm of claim 1 , wherein the base linkage comprises an actuated telescopic linkage configured to extend a length of the base linkage.

10. The robotic arm of claim 9 , wherein the first end of the base linkage is connected to a base through a fifth actuated joint configured to move the base linkage with at least one degree of freedom; and wherein the robotic arm is controlled by a control system configured to:
provide instructions to cause the control arm to move the second end effector to grasp an object between the second end effector and the first end effector by pressing the object against the first end effector using the second end effector;
provide instructions to cause the base linkage to move the object to a drop-off location while the object is grasped between the second end effector and the first end effector by:
causing the fifth actuated joint to move the base linkage with the at least one degree of freedom; and
causing the actuated telescopic linkage to extend the length of the base linkage in order to reach the drop-off location; and

provide instructions to cause the control arm to move the second end effector to release, at the drop-off location, the object grasped between the second end effector and the first end effector.

11. The robotic arm of claim 1 , wherein:
the first end effector is a shovel tool;
the second end effector is a sweeping tool; and
the robotic arm is controlled by a control system configured to provide instructions to cause the sweeping tool to move an object onto the shovel tool.

12. The robotic arm of claim 1 , wherein:
the first end effector is a storage container;
the second end effector is a gripper; and
the robotic arm is controlled by a control system configured to provide instructions to cause the gripper to pick up an object and place the object in the storage container.

13. The robotic arm of claim 1 , wherein the robotic arm is controlled by a control system configured to determine a range of motion limit of at least one of the first rotational joint, the second rotational joint, the third rotational j

Assignees

• X Dev Llc

Inventors

• Gilbertson Seth
• Weber Jeff
• Wilson Robert

Classifications

• Y10S901/01

  Mobile robot · CPC title

• A47L11/4055

  for lifting the tools to a non-working position · CPC title

• A47L11/4011

  Regulation of the cleaning machine by electric means; Control systems and remote control systems therefor · CPC title

• B25J19/007

  Means or methods for designing or fabricating manipulators · CPC title

• B25J11/0085

  Cleaning · CPC title