Decoupled six degree-of-freedom teleoperated robot system

• US 5,784,542 A
• Filed: 10/23/1996
• Issued: 07/21/1998
• Est. Priority Date: 09/07/1995
• Status: Expired due to Term

• Current Assignee: California Institute of Technology, The Guillermo Rodriguez Revocable Trust
• Original Assignee: California Institute of Technology
• Inventors: Paljug, Eric, Steve, Charles, Guillermo, Rodriguez, Das, Hari, Barlow, Ed, Ohm, Timothy, Schenker, Paul, Boswell, Curtis
• Primary Examiner(s): Davis, George B.
• Application Number:
  US08/734,967
• Time in Patent Office: 636 Days
• Field of Search: 395/95, 395/80, 395/92, 395/83, 395/82, 901/27, 901/28, 901/34, 901/36
• US Class Current: 700/260
• CPC Class Codes: A61B 2034/742 Joysticks
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 34/35 for telesurgery
• CPC Class Codes: A61B 34/37 Master-slave robots A61B34/35 takes precedence
• CPC Class Codes: A61B 34/71 Manipulators operated by drive cable mechanisms
• CPC Class Codes: A61B 34/74 Manipulators with manual electric input means
• CPC Class Codes: A61B 34/77 Manipulators with motion or force scaling
• CPC Class Codes: B25J 13/02 Hand grip control means handles or pedals for crane control B66C13/56; for measuring the force applied to control members G01L5/22; hand-held casings for switching devices, e.g. joy-sticks H01H9/0214
• CPC Class Codes: B25J 17/0241 One-dimensional joints
• CPC Class Codes: B25J 19/02 Sensing devices
• CPC Class Codes: B25J 3/04 involving servo mechanisms servo-actuated heads B25J15/02
• CPC Class Codes: B25J 9/1045 comprising tensioning means
• CPC Class Codes: B25J 9/1607 Calculation of inertia, jacobian matrixes and inverses
• CPC Class Codes: B25J 9/1689 Teleoperation
• CPC Class Codes: G05B 2219/39457 Tendon drive
• CPC Class Codes: G05B 2219/41032 Backlash
• CPC Class Codes: G05B 2219/45123 Electrogoniometer, neuronavigator, medical robot used by surgeon to operate

Abstract

The present invention is a low friction, low inertia, six-axis force feedback input device comprising an arm with double-jointed, tendon-driven revolute joints, a decoupled tendon-driven wrist, and a base with encoders and motors. The input device functions as a master robot manipulator of a microsurgical teleoperated robot system including a slave robot manipulator coupled to an amplifier chassis, which is coupled to a control chassis, which is coupled to a workstation with a graphical user interface. The amplifier chassis is coupled to the motors of the master robot manipulator and the control chassis is coupled to the encoders of the master robot manipulator. A force feedback can be applied to the input device and can be generated from the slave robot to enable a user to operate the slave robot via the input device without physically viewing the slave robot. Also, the force feedback can be generated from the workstation to represent fictitious forces to constrain the input device'"'"'s control of the slave robot to be within imaginary predetermined boundaries.

Claims

1. A robot manipulator coupled to an external device, said robot manipulator comprising:

an actuator base with plural actuators said actuator base having means for receiving forces generated by said external device;

an end effector interactive with an operator;

a force feedback sensor coupled between said end effector and said actuator base for receiving said forces from said actuator base, converting said forces into feedback forces, and providing said feedback forces to said operator;

plural arms extending seriatim between said end effector and said actuator base;

plural joints connected between pairs of adjacent arms;

wherein each one of said plural joints comprises means for mechanically coupling respective ones of said actuators to respective ones of said joints through intermediate ones of said joints, and wherein said means for mechanically coupling is decoupled from said intermediate joints;

a user interface for receiving user commands;

a servo controller coupled to said arm and wrist joints for reading actual positions of said arm and wrist joints; and

a real-time kinematic processor coupled to said user interface and said servo controller for receiving said user commands and said actual positions of said arm and wrist joints, for computing forward and inverse kinematic relationships and for controlling said arm and wrist joints in accordance with said user commands and said computed relationships.

2. The invention as set forth in claim 1, wherein said external device is a slave manipulator.

3. The invention as set forth in claim 1, wherein said external device is a programmed processor for producing fictitious forces.

4. The invention as set forth in claim 3, wherein said means for mechanically coupling comprises:

a first keying drive component coupled to a second keying drive component;

a first passing drive component coupled to respective ones of said actuators for receiving rotational motion; and

a second passing drive component coupled to said first passing drive component for receiving said rotational motion from said first passing drive component and for transmitting said received rotational motion to one of said plural joints;

wherein said first and second keying drive components are constrained to rotate about one another to define an instantaneous center of rotation;

wherein said first passing drive component rotates with respect to said second passing drive component about said instantaneous center of rotation.

5. The invention as set forth in claim 4, wherein said first keying drive component is a first keying pulley and said second keying drive component is a second keying pulley.

6. The invention as set forth in claim 5, further comprising plural keying cables for rotatably coupling said first keying pulley to said second keying pulley and for rotationally constraining said first keying pulley to said second keying pulley so that said first and second keying pulleys rotate with respect to one another about said instantaneous center of rotation.

7. The invention as set forth in claim 4, wherein said first and second keying drive components are keying spur gears.

8. The invention as set forth in claim 4, wherein said first and second passing drive components are passing spur gears.

9. The invention as set forth in claim 4, wherein said first passing drive component is a first passing pulley and said second passing drive component is a second passing pulley.

10. The invention as set forth in claim 9, further comprising plural passing cables for rotatably coupling said first passing pulley to said second passing pulley and for rotationally constraining said first passing pulley to said second passing pulley so that said first and second passing pulleys rotate with respect to one another about said instantaneous center of rotation.

11. The invention as set forth in claim 3, wherein all actuators drives of said manipulator are located within said actuator base.

12. The invention as set forth in claim 3, wherein each of said joints comprises dual independent antibacklash drive transmission preloaded with respect to one another.

13. The invention as set forth in claim 3, wherein said plural joints further comprises an antibacklash mechanism for transmitting motion without backlash from respective ones of said plural actuator drives to respective ones of said joints, said antibacklash mechanism comprising:

at least a first transmission stage comprising first dual drive components, wherein both of said first dual drive components are rotatably coupled to said respective ones of said plural actuator drives and are independently rotatable with respect to one another; and

at least a second transmission stage comprising second dual drive reduction means, wherein each one of said second dual drive reduction means is rigidly attached to one of said first dual drive components and is rotatably coupled to said respective ones of said joints, whereby rotational motion of said respective ones of said plural actuator drives is transmitted through said first and second stages, to said respective ones of said joints without backlash.

14. The invention as set forth in claim 1, further comprising a universal joint coupled to said end effector.

15. The invention as set forth in claim 1, wherein said universal joint includes dual bearing rings attached to pitch and yaw actuation links to provide decoupling of said pitch and yaw actuation links and zero backlash in all axes.

16. A robot manipulator system, comprising:

a slave manipulator coupled to a master manipulator, each of said manipulators comprising,

an actuator base with plural actuators,

an end effector,

plural arms extending seriatim between said respective end effector and said respective actuator base, and

plural joints connected between pairs of respective adjacent arms;

wherein said master manipulator further comprises a force feedback sensor coupled between said end effector and said actuator base for receiving forces from said slave manipulator, converting said forces into feedback forces, and providing said feedback forces to an operator; and

wherein each one of said plural joints of said slave and master manipulators comprises means for mechanically coupling respective ones of said actuators to respective ones of said joints through intermediate ones of said joints, and wherein said means for mechanically coupling is decoupled from said intermediate joints.

17. The invention as set forth in claim 16, wherein said means for mechanically coupling comprises:

a first keying drive component coupled to a second keying drive component;

a first passing drive component coupled to respective ones of said actuators for receiving rotational motion; and

a second passing drive component coupled to said first passing drive component for receiving said rotational motion from said first passing drive component and for transmitting said received rotational motion to one of said plural joints;

wherein said first and second keying drive components are constrained to rotate about one another to define an instantaneous center of rotation;

wherein said first passing drive component rotates with respect to said second passing drive component about said instantaneous center of rotation.

18. The invention as set forth in claim 17, wherein said first keying drive component is a first keying pulley and said second keying drive component is a second keying pulley.

19. The invention as set forth in claim 18, further comprising plural keying cables for rotatably coupling said first keying pulley to said second keying pulley and for rotationally constraining said first keying pulley to said second keying pulley so that said first and second keying pulleys rotate with respect to one another about said instantaneous center of rotation.

20. The invention as set forth in claim 17, wherein said first and second keying drive components are keying spur gears.

21. The invention as set forth in claim 17, wherein said first and second passing drive components are passing spur gears.

22. The invention as set forth in claim 17, wherein said first passing drive component is a first passing pulley and said second passing drive component is a second passing pulley.

23. The invention as set forth in claim 17, wherein all actuators drives of said manipulator are located within said actuator base.

24. The invention as set forth in claim 16, further comprising plural passing cables for rotatably coupling said first passing pulley to said second passing pulley and for rotationally constraining said first passing pulley to said second passing pulley so that said first and second passing pulleys rotate with respect to one another about said instantaneous center of rotation.

25. The invention as set forth in claim 16, wherein each of said joints comprises dual independent antibacklash drive transmission preloaded with respect to one another.

26. The invention as set forth in claim 16, wherein said plural joints further comprises an antibacklash mechanism for transmitting motion without backlash from respective ones of said plural actuator drives to respective ones of said joints, said antibacklash mechanism comprising:

at least a first transmission stage comprising first dual drive components, wherein both of said first dual drive components are rotatably coupled to said respective ones of said plural actuator drives and are independently rotatable with respect to one another; and

at least a second transmission stage comprising second dual drive reduction means, wherein each one of said second dual drive reduction means is rigidly attached to one of said first dual drive components and is rotatably coupled to said respective ones of said joints, whereby rotational motion of said respective ones of said plural actuator drives is transmitted through said first and second stages, to said respective ones of said joints without backlash.

27. The invention as set forth in claim 16, further comprising a universal joint coupled to said end effector.

28. The invention as set forth in claim 16, wherein said universal joint includes dual bearing rings attached to pitch and yaw actuation links to provide decoupling of said pitch and yaw actuation links and zero backlash in all axes.

29. The invention as set forth in claim 16, wherein each of said respective actuator base comprising plural motors and plural encoders.

30. The invention as set forth in claim 29, further comprising:

a control chassis coupled to said respective encoders of said master and slave manipulators;

a workstation coupled to said control chassis; and

an amplifier chassis coupled to said control chassis and said respective motors of said master and slave manipulators to precisely emulate movement of said master manipulator by said slave manipulator.

31. A multiple degree of freedom microsurgical robot manipulator, comprising:

a slave manipulator coupled to a master manipulator, each of said manipulators comprising,

a plurality of miniaturized decoupled robot joints comprising a plurality of arm joints each having a first keying pulley constrained to rotate about a second keying pulley, thereby defining an instantaneous center of rotation to effectuate one degree of freedom movement, and a miniaturized wrist joint coupled to one of said arm joints and having a tip and three degrees of freedom;

a plurality of miniaturized driving cables, each coupled an actuator drive at a proximal end and coupled to one of said joints at a distal end; and

a computer control system coupled between said master and said slave manipulators for precisely emulating movement of said master manipulator by said slave manipulator.

32. The invention as set forth in claim 31, wherein each of said actuator drives comprises a plurality of motors with rotational motion and having optical encoders for effecting micro-rotation of said motors and for transmitting said rotational motion of said motors to said driving cables.

33. The invention as set forth in claim 32, wherein said robot further comprises an antibacklash mechanism for transmitting motion without backlash from respective ones of said actuator drives to respective ones of said joints, said antibacklash mechanism comprising:

at least a first transmission stage comprising first dual drive components, wherein both of said first dual drive components are rotatably coupled to said respective ones of said actuator drives and are independently rotatable with respect to one another; and

at least a second transmission stage comprising second dual drive reduction means, wherein each one of said second dual drive reduction means is rigidly attached to one of said first dual drive components and is rotatably coupled to said respective ones of said joints, whereby rotational motion of said respective ones of said actuator drives is transmitted through said first and second stages, to said respective ones of said joints without backlash.

34. The invention as set forth in claim 31, further comprising plural keying cables for rotatably coupling said first keying pulley to said second keying pulley and for rotationally constraining said first keying pulley to said second keying pulley so that said first and second keying pulleys rotate with respect to one another about said instantaneous center of rotation.

35. The invention as set forth in claim 31, wherein said first and second keying pulleys are keying spur gears.