Pneumatically actuated and safely compliant skeletal joints for robotic characters

Patent metadata

Field	Value
Publication number	US-9457466-B2
Application number	US-201414460725-A
Country	US
Kind code	B2
Filing date	Aug 15, 2014
Priority date	Aug 15, 2014
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

A robot that includes two or more skeletal or rigid links interconnected by a joint. The joint is pneumatically actuated and includes a pneumatic joint actuator that allows the robot's skeletal links to be moved in an expressive manner. The pneumatic actuator includes a pair of opposing air bladders encased within a housing or body of the joint. Each air bladder is positioned on an opposite side of an actuating lever arm, which is rigidly attached to one of the skeletal links and is pivotally mounted on the joint body or housing. Movement of the actuating lever arm causes the attached skeletal link to pivot. To obtain this selective movement, one of the two air bladders is filled with a gas, such as air, while the other is left un-inflated or less inflated, and this forces the lever arm and attached skeletal link to pivot about their mounting point.

First claim

We claim:

1. A robotic joint assembly, comprising:
a first skeletal link with a body extending from a first end to a second end;
a joint, mounted to the second end of the first skeletal link, comprising a joint housing with sidewalls defining an interior space and further comprising a pivotal mounting element supported in the joint housing;
a second skeletal link with a body extending from a first end to a second end, wherein the first end of the body is pivotally coupled to the pivotal mounting element of the joint housing; and
a pneumatic joint actuator comprising first and second gas bladders positioned within the interior space of the joint housing, wherein the second skeletal link is pivoted with inflation of at least one of the first and second gas bladders,
wherein the first skeletal link comprises a first flow conduit extending through the body of the first skeletal link that is coupled at one end to an inlet to the first gas bladder and wherein the first skeletal link further comprises a second flow conduit extending through the body of the first skeletal link that is coupled at one end to an inlet to the second gas bladder.

2. The assembly of claim 1 , further comprising an actuating lever arm extending outward from the first end of the body of the second skeletal link into the interior space to be disposed between the first and second gas bladders, wherein movement of the actuating lever arm urges the first end of the body of the second skeletal link to pivot about the pivotal mounting element.

3. The assembly of claim 2 , wherein the selective inflation of the first gas bladder causes the first gas bladder to apply a first actuation force on a first side of the actuating lever arm and inflation of the second gas bladder causes the second gas bladder to apply a second actuation force on a second side opposite the first side, whereby the first and second actuation forces are opposing forces.

4. The assembly of claim 2 , wherein the joint housing comprises encasement barriers in the interior space defining, with the sidewalls of the housing, first and second encasements in which the first and second gas bladders are placed and wherein the actuating lever arm extends between first and second encasements.

5. The assembly of claim 1 , wherein the first and second gas bladders comprise an inflatable bag formed from a flexible and compliant material.

6. The assembly of claim 1 , further comprising a first control gas supply fluidically linked to the first flow conduit and a second control gas supply fluidically linked to the second flow conduit, wherein the first and second control gas supplies are independently operable to provide a pressurized gas to the first and second flow conduits to perform the selective inflation of the first and second gas bladders.

7. The assembly of claim 6 , further comprising a joint controller providing control signals to the first and second control gas supplies to perform the selective inflation to move the second skeletal link through a predefined motion profile.

8. The assembly of claim 7 , further comprising first and second pressure sensors sensing pressures in the first and second flow conduits and, in response, providing pressure feedback signals to the joint controller, wherein the joint controller processes the pressure feedback signals and generates the control signals based on the pressure feedback signal processing and wherein the pressures are maintained, by the joint controller, below a predefined maximum, whereby the first and second gas bladders are compressible in response to an external force being applied to the first or second skeletal link.

9. A robotic joint assembly, comprising:
a first skeletal link with a body extending from a first end to a second end;
a joint, mounted to the second end of the first skeletal link, comprising a joint housing with sidewalls defining an interior space and further comprising a pivotal mounting element supported in the joint housing;
a second skeletal link with a body extending from a first end to a second end, wherein the first end of the body is pivotally coupled to the pivotal mounting element of the joint housing;
a pneumatic joint actuator comprising first and second gas bladders positioned within the interior space of the joint housing, wherein the second skeletal link is pivoted with inflation of at least one of the first and second gas bladders;
an additional joint housing pivotally attached to the second end of the body of the second skeletal link;
a third gas bladder filled with a fixed volume of a gas, wherein the third gas bladder extends through or on the body of the second skeletal link with a first end positioned in the interior space of the joint housing and abutting one or more exterior surfaces of the first end of the second skeletal link and with a second end positioned in an interior space of the additional joint housing; and
an additional actuating lever arm extending outward from the second end of the second skeletal link into the interior space of the additional joint housing,
wherein the first end of the third gas bladder is compressed during pivoting of the second skeletal link on the pivotal mounting element and, in response, the second end of the third gas bladder is expanded causing the second end of the third gas bladder to apply an additional actuating force, whereby the additional joint housing pivots on the second end of the body of the second skeletal link.

10. The assembly of claim 1 , wherein the second skeletal link is pivoted about a longitudinal axis of the body of the second skeletal link with the inflation of at least one of the first and second gas bladders.

11. A robot with expressive and compliant movement, comprising:
first and second structural elements;
a joint joining a portion of the first structural element to a portion of the second structural element, wherein the second structural element is pivotal about the portion of the first structural element; and
a pneumatic actuator comprising a first gas bladder and a second gas bladder positioned in the joint, wherein the second structural element pivots in a first direction when the first gas bladder is inflated to a pressure greater than a pressure in the second gas bladder and wherein the second structural element pivots in a second direction opposite the first direction when the second gas bladder is inflated to a pressure greater than a pressure in the first gas bladder;
a first flow channel in the first structural element with an outlet coupled to an inlet of the first gas bladder; and
a second flow channel in the first structural element with an outlet coupled to an inlet of the second gas bladder, whereby control gas may selectively be directed to flow through the first structural element to one or both of the first and second gas bladders to actuate the joint.

12. The robot of claim 11 , wherein a lever arm extends from an end of the second structural element to be disposed between the first and second gas bladders, whereby the first and second gas bladders apply opposing actuation forces on opposite sides of the lever arm.

13. The robot of claim 11 , further comprising first and second gas supplies independently operable to provide the control gas to the first and second gas bladders, respectively, and wherein the robot further includes a joint controller controlling operation of the first and second gas supplies to a rotate or move the second structural by pressurizing the first and second gas bladders to first and second pressures.

14. The robot of claim 11 , wherein the first and second gas bladders are formed of flexible material sele

Assignees

• Disney Entpr Inc

Inventors

• Robertson James R
• Jackson Philip J

Classifications

• B25J17/0233

  with radial compliance, i.e. perpendicular to the longitudinal wrist axis · CPC title

• B25J19/068

  Actuating means with variable stiffness · CPC title

• B25J19/063

  working only upon contact with an outside object · CPC title

• B25J17/00

  Joints · CPC title

• B25J19/0091

  Shock absorbers (in general F16F) · CPC title