Dual arm master controller for a bilateral servo-manipulator

• US 4,883,400 A
• Filed: 08/24/1988
• Issued: 11/28/1989
• Est. Priority Date: 08/24/1988
• Status: Expired due to Fees

• Current Assignee: Martin Marietta Energy Systems, Inc. (Martin Marietta Corporation)
• Original Assignee: Martin Marietta Energy Systems, Inc. (Martin Marietta Corporation)
• Inventors: Perkins, Gerald S., Kuban, Daniel P.
• Primary Examiner(s): Spar, Robert J.
• Assistant Examiner(s): ELLER JR, JAMES
• Application Number:
  US07/236,068
• Time in Patent Office: 461 Days
• Field of Search: 414/730, 414/2, 414/5, 414/8, 414/1, 414/3, 414/4, 414/6, 414/7, 901/8, 901/9
• US Class Current: 414/2
• CPC Class Codes: B25J 3/04 involving servo mechanisms servo-actuated heads B25J15/02

Abstract

A master controller for a mechanically dissimilar bilateral slave servo-manipulator is disclosed. The master controller includes a plurality of drive trains comprising a plurality of sheave arrangements and cables for controlling upper and lower degrees of master movement. The cables and sheaves of the master controller are arranged to effect kinematic duplication of the slave servo-manipulator, despite mechanical differences therebetween. A method for kinematically matching a master controller to a slave servo-manipulator is also disclosed.

Claims

1. A master controller for controlling a mechanically dissimilar slave servo-manipulator;

the slave servo-manipulator comprising a first slave member, a first slave joint and a first slave drive train cooperating to define a first degree of slave movement, a second slave member connected with said first slave member, a second slave joint, and a second slave drive train operative through said first and second slave joints so as to define a second, lower degree of slave movement, said first and second slave drive trains including gears located at said first and second slave joints, said gears defining at said first slave joint a first torsional cross-coupling ratio, and said gears defining between said first and second slave joints a first positional cross-coupling ratio; and

said master controller comprising a first master member, a first master joint and a first master drive train cooperating to define a first degree of master movement, a second master member connected with said first master member, a second master joint, and a second master drive train operative through said first and second master joints so as to define a second, lower degree of master movement, said first and second master members and said first and second master joints being mutually arranged so as to replicate identically the kinematic arrangement of said first and second slave members and said first and second slave joints, said first and second master drive trains including sheaves located at said first and second master joints, said sheaves defining at said first master joint a second torsional cross-coupling ratio equal to said first torsional cross-coupling ratio, and said sheaves defining between said first and second master joints a second positional cross-coupling ratio equal to said first positional cross-coupling ratio.

2. A master controller as claimed in claim 1, wherein said first and second slave drive trains include torque tube means for transmitting torque to said gears, and said first and second master drive trains include cable means for transmitting torque to said sheaves.

3. A master controller for controlling a mechanically dissimilar slave servo-manipulator, said master controller comprising:

an arrangement of master members and master joints identically replicating the kinematic arrangement of the slave servo-manipulator, the arrangement including first and second master joints that kinematically replicate first and second slave joints of the slave servo-manipulator, respectively; and

means for transmitting torsional loads through said first and second master joints of said arrangement, said transmitting means being mechanically dissimilar from corresponding torsional load transmitting means of the slave servomanipulator, said master controller transmitting means including a first drive element located at said first master joint for producing a first degree of movement in said arrangement, a second drive element located at said first master joint and a third drive element located at said second master joint, said second and third drive elements cooperating to produce a second, lower degree of movement in said arrangement, wherein said first drive element is proportioned relative to said second drive element so as to match the torsional cross-coupling ratio of the first slave joint, and said second drive element is proportioned relative to said third drive element so as to match the positional cross-coupling ratio existing between the first and second slave joints.

4. A method for controlling a slave servomanipulator, said method comprising the steps of:

manually operating an arrangement of members and joints that kinematically replicate the slave servo-manipulator; and

producing cross-coupling loads in said arrangement identical to cross-coupling loads produced in the slave servo-manipulator, wherein the identical cross-coupling loads are produced by;

transmitting torsional loads along the joints of said arrangement with a mechanical drive train different from that of the slave servomanipulator, matching the cross-coupling load at each joint in the arrangement to the cross-coupling load of the corresponding joint of the slave servomanipulator, and

matching the positional cross-coupling ratio between joints in the arrangement to the positional cross-coupling ratio between corresponding joints of the slave servo-manipulator.

5. A method as claimed in claim 4, wherein said torsional load transmitting step includes operating cables and sheaves located in said arrangement while operating torque tubes and gears in the slave servo-manipulator.

6. A master controller for controlling a slave servo-manipulator, comprising:

at least one manually manipulative arm including a shoulder joint, an upper arm member extending from said shoulder joint, a forearm member, an elbow joint operative between a proximal end portion of said forearm member and said upper arm member, means for actuating a tong arrangement of the slave servo-manipulator, and a wrist joint operative between a distal end portion of said forearm member and said actuating means;

a plurality of motors located adjacent one another at said shoulder joint;

means for transmitting the output of said motors to said members through said joints, said transmitting means including sheaves located at said joints and a plurality of cables within said members extending between said joints and engaging said sheaves, said sheaves having diameters so as to provide a torque cross-coupling that substantially duplicates the torque cross-coupling in the corresponding slave joints;

said sheaves also providing positional cross-coupling between adjacent joints of said master controller that substantially duplicates the positional cross-coupling between corresponding joints of the slave servo-manipulator.

7. A method for kinematically matching a master controller with a mechanically dissimilar slave servo-manipulator unit, comprising the steps of:

determining a torsional cross-coupling fraction in a joint of said slave unit;

determining a positional cross-coupling fraction between joints of said slave unit;

matching the determined torsional crosscoupling fraction by selecting drive ratios at a geometrically corresponding joint of said master controller; and

matching the determined positional crosscoupling coupling by selecting relative drive ratios between geometrically corresponding joints of said master controller.