Robotic apparatus

Abstract

A robotic apparatus has eight actuators (M0-M7) and a linkage (LINK 0-LINK 5) that actuates an end effector. Three serial macro freedoms have large ranges of motion and inertias. Four serial micro freedoms have small ranges of motion and inertias. Translation of the end effector in any direction is actuated by at least one micro joint and at least one macro joint. The apparatus can be part of a master and slave combination, providing force feedback without any explicit force sensors. The slave is controlled with an Inverse Jacobian controller, and the master with a Jacobian Transpose controller. A slave having more degrees of freedom (DOFs) than the master can be controlled. A removable effector unit actuates its DOFs with cables. Beating heart surgery can be accomplished by commanding the slave to move with a beating heart and cancelling out any such motion in the motions perceived by the master.

1 - 37 . (canceled) 
     
     
         38 . An apparatus comprising:
 a base positioner having at least two degrees of freedom; and   a shaft having a proximal end and a distal end, the proximal end of the shaft removably coupled to said base positioner, said shaft further translatable relative to said distal portion along a longitudinal axis; and   a wrist unit coupled to the distal end of the shaft, the wrist unit movable in at least four degrees of freedom, wherein at least two of the four degrees of freedom are redundant relative to each other.   
     
     
         39 . The apparatus of  claim 38 , the wrist unit movable in no more than four degrees of freedom. 
     
     
         40 . The apparatus of  claim 38 , the wrist unit comprising first and second fingers each rotatable about a yaw axis, the at least two redundant degrees of freedom comprising rotation of the wrist unit about first and second pitch axes perpendicular to the yaw axis, the first and second pitch axes being parallel and offset relative to each other. 
     
     
         41 . The apparatus of  claim 40 , the at least four degrees of freedom comprising rotation of the shaft about the longitudinal axis. 
     
     
         42 . The apparatus of  claim 41 , wherein the yaw axis is the most distal degree of freedom of the wrist relative to the base positioner, and the rotation is the most proximal degree of freedom of the wrist relative to the base positioner. 
     
     
         43 . The apparatus of  claim 40 , further comprising:
 first and second capstans rotatably coupled to a distal portion of the wrist unit by respective first and second capstan joints;   first, second, third, and fourth intermediate idler pulleys mounted on the first pitch axis to independently rotate about the first pitch axis;   first and second cables engaging, in a first circumferential orientation, the first and second intermediate idler pulleys respectively, the first and second cables further engaging the first capstan;   third and fourth cables engaging, in a second circumferential orientation opposite the first circumferential orientation, the third and fourth intermediate idler pulleys respectively, the third and fourth cables further engaging the second capstan.   
     
     
         44 . The apparatus of  claim 43 , further comprising:
 fifth, sixth, seventh, and eighth intermediate idler pulleys mounted on the second pitch axis to independently rotate about the second pitch axis, wherein the second pitch axis is more distal from the base positioner relative to the first pitch axis;   the first and second cables further engaging the fifth and sixth intermediate idler pulleys respectively, and the third and fourth cables further engaging the seventh and eighth intermediate idler pulleys, respectively.   
     
     
         45 . The apparatus of  claim 40 , further comprising force sensors capable of measuring forces exerted on the fingers. 
     
     
         46 . The apparatus of  claim 45 , said force sensors capable of measuring forces exerted on the fingers in a direction perpendicular to said first and second pitch axes. 
     
     
         47 . The instrument of  claim 43 , the first and second capstans having different diameters. 
     
     
         48 . The apparatus of  claim 38 , the base positioner comprising a remote center positioner. 
     
     
         49 . The apparatus of  claim 38 , the shaft releasably coupleable to a distal portion of said base positioner. 
     
     
         50 . The apparatus of  claim 38 , the shaft comprising a sliding bracket coupling the shaft to the base positioner, the apparatus further comprising:
 actuators disposed at the sliding bracket, the actuators coupled to the wrist unit by cables to rotate the wrist unit about at least one of said at least four degrees of freedom.   
     
     
         51 . The instrument of  claim 50 , further comprising an instrument base coupled to the proximal end of the shaft by a rotary joint, the instrument base comprising a slidable bracket housing the actuators. 
     
     
         52 . The instrument of  claim 51 , the instrument base further comprising support brackets connected together by a support rod and two guide rails. 
     
     
         53 . The apparatus of  claim 40 , the wrist unit comprising:
 a first distal joint coupled to said distal end of said elongate shaft, said first distal joint having a first joint axis substantially perpendicular to said longitudinal axis;   a first distal link movably coupled to said first distal joint;   a second distal joint coupled to said first distal joint via said first distal link, said second distal joint having a second joint axis substantially parallel to said first joint axis;   a second distal link movably coupled to said second distal joint; and   a third distal joint coupled to said second distal joint via said second distal link, said third distal joint movably coupled to said fingers.   
     
     
         54 . The apparatus of  claim 53 , further comprising a master controller having a master unit linkage, wherein input commands from an operator to said master unit linkage cause the controller to control movement of the base positioner, the shaft, and the wrist unit according to said input commands. 
     
     
         55 . The apparatus of  claim 54 , wherein the shaft and the wrist unit contain no actuators for causing motion about the first and second distal joints. 
     
     
         56 . The apparatus of  claim 54 , wherein forces experienced by the wrist unit are reproduced at the master controller to provide an operator with force feedback, wherein the reproduced forces at the master controller are scaled increments of the forces experienced by the wrist unit. 
     
     
         57 . The apparatus of  claim 38 , the at least two degrees of freedom of the base positioner and the translation along the longitudinal axis corresponding to macro degrees of freedom, the at least four degrees of freedom of the wrist unit corresponding to micro degrees of freedom, wherein at least one macro degree of freedom and at least one micro degree of freedom are redundant with respect to each other. 
     
     
         58 . The apparatus of  claim 57 , wherein each macro degree of freedom is redundant with respect to a micro degree of freedom.