System and method for breakaway clutching in an articulated arm

• US 10,449,008 B2
• Filed: 06/21/2018
• Issued: 10/22/2019
• Est. Priority Date: 03/17/2014
• Status: Active Grant

• Current Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Original Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Inventors: Miller, Daniel, Swarup, Nitish, Turner, Michael, Hourtash, Arjang M., Griffiths, Paul G., Mohr, Paul W.
• Primary Examiner(s): Figueroa, Jaime
• Application Number:
  US16/014,619
• Publication Number:
  US 20180296284A1
• Time in Patent Office: 488 Days
• Field of Search: 700245, 700258
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2018/00672 lower
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2034/305 Details of wrist mechanisms at distal ends of robotic arms
• CPC Class Codes: A61B 2090/035 preventing further rotation
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: B25J 13/085 Force or torque sensors B25J13/082, B25J13/084 take precedence
• CPC Class Codes: B25J 13/088 with position, velocity or acceleration sensors
• CPC Class Codes: B25J 9/1689 Teleoperation
• CPC Class Codes: B25J 9/1694 characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion

Abstract

A system and method of breakaway clutching in a computer-assisted medical device includes an articulated arm having one or more first joints and a control unit coupled to the articulated arm and having one or more processors. The control unit operates each of the first joints in multiple states. The multiple states include a locked state, wherein movement of respective first joints is restricted, and a float state, wherein movement of the respective first joints is permitted. The control unit further switches one or more second joints selected from the first joints from the locked state to the float state when a stimulus on the second joints exceeds one or more unlock thresholds and switches the second joints from the float state to the locked state when a velocity of each of the second joints is below one or more lock thresholds.

Claims

1. A device comprising:

an arm comprising a first joint; and

a control unit coupled to the arm and comprising one or more processors;

wherein the control unit;

switches the first joint from a locked state of the first joint to a float state of the first joint in response to a stimulus associated with the first joint exceeding a first unlock threshold, wherein movement of the first joint is more restricted in the locked state of the first joint than in the float state of the first joint; and

switches the first joint from the float state to the locked state in response to a velocity associated with the first joint falling below a first lock threshold.

2. The device of claim 1, wherein:

the arm further comprises a second joint; and

the control unit further switches the second joint from a locked state of the second joint to a float state of the second joint in response to the stimulus associated with the first joint exceeding the first unlock threshold.

3. The device of claim 1, wherein the control unit further commands, on condition that the first joint is in the float state, the first joint to move to a commanded position based on a current actual position of the first joint, or to a commanded velocity based on a current actual velocity of the first joint.

4. The device of claim 1, wherein the control unit further releases one or more brakes on the first joint when the first joint is a non-actuated joint and the first joint is in the float state.

5. The device of claim 1, wherein the control unit further switches the first joint from the float state to the locked state when the velocity of the first joint is below the first lock threshold continuously for a predetermined period of time.

6. The device of claim 1, wherein the control unit further commands, on condition that the first joint is in the float state, the first joint to move to a current actual position of the first joint.

7. The device of claim 1, wherein:

the control unit further commands, on condition that the first joint is in the float state, the first joint to move to a commanded position based on a current actual position of the first joint; and

the commanded position is between the current actual position and a previous commanded position.

8. The device of claim 1, wherein:

the control unit further commands, on condition that the first joint is in the float state, the first joint to move to a commanded velocity based on a current actual velocity of the first joint; and

the commanded velocity is lower than the current actual velocity.

9. The device of claim 1, wherein the control unit further prevents switching of the first joint to the float state when an operating mode of the device corresponds to a transport mode, a teleoperation mode, a commanded motion mode, or a docked to a patient mode.

10. A method of controlling a device having an arm, the method comprising:

switching, using a control unit having one or more processors, a first joint of the arm from a locked state of the first joint to a float state of the first joint in response to a stimulus associated with the first joint exceeding a first unlock threshold, wherein movement of the first joint is more restricted in the locked state of the first joint than in the float state of the first joint; and

switching, using the control unit, the first joint from the float state to the locked state in response to a velocity associated with the first joint falling below a first lock threshold.

11. The method of claim 10, further comprising switching a second joint of the arm from a locked state of the second joint to a float state of the second joint in response to the stimulus associated with the first joint exceeding the first unlock threshold.

12. The method of claim 10, further comprising commanding, on condition that the first joint is in the float state, the first joint to move to a commanded position based on a current actual position of the first joint, or to a commanded velocity based on a current actual velocity of the first joint.

13. The method of claim 12, wherein the commanded position is the current actual position or is between the current actual position and a previous commanded position.

14. The method of claim 12, wherein the commanded velocity is lower than the current actual velocity.

15. The method of claim 10, wherein the control unit further prevents switching of the first joint to the float state when an operating mode of the device corresponds to a transport mode, a teleoperation mode, a commanded motion mode, or a docked to a patient mode.

16. The method of claim 10, further comprising switching the first joint from the float state to the locked state when the velocity of the first joint is below the first lock threshold continuously for a predetermined period of time.

17. A non-transitory machine-readable medium comprising a plurality of machine-readable instructions which when executed by one or more processors associated with a device are adapted to cause the one or more processors to perform a method comprising:

switching a first joint of an arm of the device from a locked state of the first joint to a float state of the first joint in response to a stimulus associated with the first joint exceeding a first unlock threshold, wherein movement of the first joint is more restricted in the locked state of the first joint than in the float state of the first joint; and

switching the first joint from the float state to the locked state in response to a velocity associated with the first joint falling below a first lock threshold.

18. The non-transitory machine-readable medium of claim 17, wherein the method further comprises switching a second joint of the arm from a locked state of the second joint to a float state of the second joint in response to the stimulus associated with the first joint exceeding the first unlock threshold.

19. The non-transitory machine-readable medium of claim 17, wherein the method further comprises commanding, on condition that the first joint is in the float state, the first joint to move to a commanded position based on a current actual position of the first joint, or to a commanded velocity based on a current actual velocity of the first joint.

20. The non-transitory machine-readable medium of claim 17, wherein the method further comprises switching the first joint from the float state to the locked state when the velocity of the first joint is below the first lock threshold continuously for a predetermined period of time.