US5239246A
Expired / Lapsed
US
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Force reflection with compliance control
Assignee: United States, ADMINISTRATOR OF NASA, Secretary of
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Filing: 1992-07-08
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Granted: 1993-08-24
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Expires: 2012-07-08
Abstract
Abstract Two classes of systems for force-reflecting control that enable high force-reflection gain are presented: position-error-based force reflection and low-pass-filtered force reflection, both combined with shared compliance control. In the position-error-based class, the position error between the commanded and the actual position of a compliantly controlled robot is used to provide force reflection. In the low-pass-filtered force reflection class, the low-pass-filtered output of the compliance control is used to provide force reflection. The increase in force reflection gain can be more than 10-fold as compared to a conventional high-bandwidth pure force reflection system, when high compliance values are used for the compliance control.
Inventors
- 👤 Won S. Kim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:17
CPC Classifications
B; B25; B25J; B25J9/00; B25J9/16; B25J9/1628; B25J9/1633
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
345 words
In a system for teleoperation of a robot arm providing an operator with force reflection through a force-reflecting hand controller in combination with a shared compliance control for each Cartesian coordinate axis of the teleoperation system, a force-reflecting control architecture combined with shared compliance control architecture in one system comprising, means for transmitting from said hand controller a commanded position signal, HC, with gain, G ps , a robot servo system at said robot arm responsive to a servo control input signal for driving said robot arm to an actual commanded position, and producing a signal representative of actual position of said robot arm, a signal mixer coupling said servo control input signal for a commanded position to said robot servo system, said signal mixer modifying said servo control input signal in response to a low-pass filtered contact force signal to produce an actual servo control signal that is a function of the difference between said servo control input signal and said low-pass filtered contact force signal with compliance control feedback gain, G cc , for actual positioning of said robot arm, means for sensing contact force generated by said actual positioning of said robot arm for producing a contact force signal proportional to a force of reaction due to contact or torque when said arm is in contact with an object, a low-pass filter coupling said contact force signal to said mixer with said compliance control feedback gain as said low-pass filtered contact signal, means for producing a force reflection signal that is a function of said commanded position signal, HC, with gain G ps , transmitted to said robot arm and a selected one of two signals, namely a signal representing actual position of said robot arm effected by said robot servo control signal, and said force contact signal without compliance control feedback gain, G cc , and means for transmitting said force reflection signal to said hand controller, whereby said operator responds to said force reflection hand controller for producing a following commanded position signal for transmittal to said robot servo system.
Claim 2
Dependent Claim
345 words
In a system for teleoperation of a robot arm providing an operator with force reflection through a force-reflecting hand controller in combination with a shared compliance control for each Cartesian coordinate axis of the teleoperation system, a force-reflecting control architecture combined with shared compliance control architecture in one system comprising, means for transmitting from said hand controller a commanded position signal, HC, with gain, G ps , a robot servo system at said robot arm responsive to a servo control input signal for driving said robot arm to an actual commanded position, and producing a signal representative of actual position of said robot arm, a signal mixer coupling said servo control input signal for a commanded position to said robot servo system, said signal mixer modifying said servo control input signal in response to a low-pass filtered contact force signal to produce an actual servo control signal that is a function of the difference between said servo control input signal and said low-pass filtered contact force signal with compliance control feedback gain, G cc , for actual positioning of said robot arm, means for sensing contact force generated by said actual positioning of said robot arm for producing a contact force signal proportional to a force of reaction due to contact or torque when said arm is in contact with an object, a low-pass filter coupling said contact force signal to said mixer with said compliance control feedback gain as said low-pass filtered contact signal, means for producing a force reflection signal that is a function of said commanded position signal, HC, with gain G ps , transmitted to said robot arm and a selected one of two signals, namely a signal representing actual position of said robot arm effected by said robot servo control signal, and said force contact signal without compliance control feedback gain, G cc , and means for transmitting said force reflection signal to said hand controller, whereby said operator responds to said force reflection hand controller for producing a following commanded position signal for transmittal to said robot servo system.
Claim 3
Dependent Claim
45 words
A system as defined in claim 1 wherein said means for producing said force reflection signal produces a signal proportional to the difference between said actual robot position signal and said commanded position signal, HC, transmitted with gain, G ps , by said hand controller.
Claim 4
Dependent Claim
46 words
A system as defined in claim 1 wherein said means for producing said force reflection signal produces a signal proportional to the difference between said servo control input signal from said signal mixer and said commanded position signal transmitted to said mixer by said hand controller.
Claim 5
Dependent Claim
47 words
A system as defined in claim 1 wherein said force reflection signal comprises said contact force signal, which is itself a function of said commanded position signal, filtered by said low-pass filter without said position signal, filtered by said low-pass filter without said gain, G ps .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-23 | 1997-02-22 | 1997-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-23 | 2001-02-22 | 2001-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-23 | 2005-02-22 | 2005-08-24 | $7700.00 | Window Closed / Lapsed |