Robotic apparatus

Abstract

A robotic apparatus has eight actuators (M 0 -M 7 ) 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 an y 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 mater 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 . A method for controlling movement of a robotic instrument at a worksite, the method comprising:
 positioning a distal end of said instrument at the worksite in the vicinity of a portion of a moving target;   tracking the motion of said portion of said moving target; and   causing said robotic instrument to track the motion of said portion of said moving target, such that said instrument is substantially stationary relative to the portion of the moving target.   
     
     
         39 . The method of  claim 38 , said distal end of said instrument coupled to a wrist element, said wrist element coupled to an end effector, said wrist element having a plurality of wrist segments pivotally jointed together, the method further comprising:
 moving at least a portion of said wrist element to permit said end effector element to track motion of said moving portion without moving said longitudinal shaft of said instrument.   
     
     
         40 . The method of  claim 39 , said wrist element comprising a plurality of wrist segments pivotally coupled together, said wrist segments providing the instrument with redundant degrees of freedom of motion, the method further comprising:
 causing said end effector to track said movement by pivoting the wrist segments while the elongate shaft remains substantially stationary relative to an aperture, such that the distance between said end effector and said moving portion remains substantially fixed.   
     
     
         41 . The method of  claim 39 , said tracking the motion comprising:
 contacting said target directly with a portion of a motion detector, the portion of the motion detector supported by joints that move in relation to the moving target portion;   manipulating a remote master control to move the robotic instrument relative to said moving target; and manipulating said target.   
     
     
         42 . The method of  claim 38 , further comprising passing said robotic instrument through an aperture. 
     
     
         43 . The method of  claim 38 , wherein said target comprises an element in a nuclear facility. 
     
     
         44 . The method of  claim 38 , wherein said target comprises a radioactive substance. 
     
     
         45 . The method of  claim 38 , further comprising:
 detecting an image of at least said portion of said moving target; and   transmitting said image to a remote display device.   
     
     
         46 . The method of  claim 45 , further comprising:
 processing the image so that an observer observing the display device perceives the moving target to be substantially stationary.   
     
     
         47 . The method of  claim 45 , comprising detecting said image with a viewing camera. 
     
     
         48 . The method of  claim 38 , wherein the tracking step includes tracking the motion of said portion of said moving target by directly contacting said portion with a contacting surface of said motion sensor, wherein said motion sensor further comprises an articulated linkage, and a plurality of optical encoders. 
     
     
         49 . The method of  claim 38 , wherein the tracking step includes tracking the motion of said portion of said moving target by directly contacting said portion with a horseshoe-shape of the contacting surface of a motion sensor. 
     
     
         50 . The method of  claim 38 , said instrument having a distal wrist element coupled by a wrist joint to an elongate shaft, said wrist element movably coupled to an end effector, wherein said causing said instrument to track movement comprises causing a portion of said instrument distal of said wrist joint to track motion. 
     
     
         51 . The method of  claim 39 , said instrument comprising a longitudinal axis, and wherein said wrist element comprises at least two wrist segments, wherein said causing the portion of said instrument distal of said wrist joint to track motion comprises causing at least one of said wrist segments to translate along a segment axis substantially parallel to said longitudinal axis without moving said instrument proximal of said wrist element along said longitudinal axis. 
     
     
         52 . A servomechanical system comprising:
 a master unit having a movable master;   a slave unit having a surgical end effector, the slave moving the end effector in response to movement of the master;   a controller coupling the master unit to the slave unit so that an operator manipulating the master can direct the surgical end effector in performing a surgical procedure on a moving organ; and   means for stabilizing an image of a portion of the moving organ, wherein the stabilizing means comprises a sensor in direct contact with said portion of the organ, for measuring movement of said portion of the organ.   
     
     
         53 . The servomechanical system of  claim 52 , wherein the controller calculates a frame of reference of the heart using the measured organ movement, the system further comprising a camera arm that moves in response to the organ frame of reference. 
     
     
         54 . The servomechanical system of  claim 53 , wherein the slave moves the end effector in response to the organ frame of reference, such that the end effector appears substantially motionless relative to said moving portion of the organ. 
     
     
         55 . The servomechanical system of  claim 52 , wherein said sensor comprises a mechanical arm with an end that is placed against the moving organ while the end effector is used to perform the surgical procedure. 
     
     
         56 . The servomechanical system of  claim 52 , the slave unit further comprising an articulate robotic arm and a robotic surgical instrument releasably coupleable to a distal portion of said articulate arm, said instrument comprising:
 at least a first end effector element movably coupled to a wrist portion, and   an elongate shaft having a proximal portion coupleable to said articulate arm, said elongate shaft having a longitudinal axis and a distal end coupled to said wrist portion, said wrist portion having at least two segments, each of said segments having a segment axis, said segments movably coupled together in such a way that at least one of said segment axes can be positioned substantially parallel to said longitudinal axis of said elongate shaft;   wherein said controller controls movement of the instrument based on information provided by the sensor to the controller such that the distance between the end effector and said portion of the moving organ remains substantially constant.   
     
     
         57 . The servomechanical system of  claim 56 , wherein an operator is able to control movement of said instrument relative to the moving organ by providing input commands to said master unit, said input commands comprising the operator moving at least one master control handle, wherein movement of said instrument corresponds to a scaled increment of said movement of said master control handle. 
     
     
         58 . The servomechanical system of  claim 57 , wherein forces experienced by the instrument during a surgical procedure are reproduced at the master control handle to provide the operator with force feedback, wherein the reproduced forces at the master are scaled increments of the forces experienced by the instrument. 
     
     
         59 . The servomechanical system of  claim 58 , wherein the reproduced forces are reproduced in three degrees of freedom of movement of the master unit, corresponding to three degrees of freedom of movement of the instrument. 
     
     
         60 . The servomechanical system of  claim 58 , wherein the reproduced forces at the master correspond to an amplification of the forces experienced by the instrument. 
     
     
         61 . The servomechanical system of  claim 52 , the moving organ comprising a beating heart. 
     
     
         62 . An actuator set comprising:
 a plurality of actuators, each actuator having a first and a second terminal, the second of which is rotatable about an output axis relative to the first, which second terminal is adapted to engage a transmission element, each of the output axes having a component thereof that is parallel;   for each of the actuators, a transmission element that is looped around the rotatable terminal, forming two tension segments;   wherein each transmission element comprises:   a pair of low friction circular surfaces, along each of which passes one of the two tension segments, the pair of circular surfaces being centered about an axis that is substantially perpendicular to a component of the output axis of the respective actuator; and   a turnaround located along the path of the transmission element between the points at which it engages each pulley of the pair, such that tension is maintained on the transmission element.   
     
     
         63 . The actuator set of  claim 62 , the plurality of actuators comprising at least three actuators, the actuators arranged such that the output axes are substantially parallel. 
     
     
         64 . The actuator set of  claim 62 , the plurality of actuators comprising at least three actuators, the actuators arranged in two sets, which sets join in at most one actuator, such that, for each set, the output axes are substantially coplanar. 
     
     
         65 . The actuator set of  claim 62 , the plurality of actuators comprising at least three actuators, each of the actuators having associated therewith an actuator plane in which the respective output axis lies, and which actuator plane is substantially equidistant and between the pair of tension segments, the actuators arranged such that the respective actuator planes are spaced from each other a sufficient distance so that the respective tension segments may pass to the circular surfaces free of interference with any tension segment that is associated with any others of the plurality of actuators. 
     
     
         66 . The actuator set of  claim 62 , the plurality of actuators comprising at least three actuators, the actuators arranged in two sets, which sets form a V shape. 
     
     
         67 . The actuator set of  claim 66 , the actuators arranged such that the apex of the V shape points away from the pairs of circular surfaces. 
     
     
         68 . The actuator set of  claim 62 , the actuators arranged such that the apex of the V shape points toward the pairs of circular surfaces. 
     
     
         69 . The actuator set of  claim 66 , the plurality comprising six. 
     
     
         70 . The actuator set of  claim 62 , the actuators comprising rotary motors. 
     
     
         71 . The actuator set of  claim 63 , the actuators further being supported in a structure that maintains clearance between actuators located at the ends of the open links of the V, such that other elements of a mechanism actuated by the actuators can move between the actuators that are located at the ends of the V. 
     
     
         72 . The actuator set of  claim 62  further comprising, for each of the transmission elements, transmission support members that train the transmission elements along substantially parallel paths to a point for each where it couples to an element that is movable through a different degree of freedom. 
     
     
         73 . A robotic apparatus comprising a base unit and an effector unit, the base unit comprising an actuator set of any of the preceding claims, wherein the actuator set comprises a plurality of actuators configured to actuate the base linkage and the effector linkage, the base unit further comprising:
 a support;   a base linkage, connected at a support end to the support, and connected at an effector end to the effector unit;   
       the effector unit comprising:
 a base end, connected to the effector end of the base linkage; 
 an end effector; 
 an effector linkage comprising a plurality of links and joints, which effector linkage extends from the base end to the end effector; 
 
       wherein:
 for each joint, an effector transmission element is connected to a link that is adjacent the joint and that also has a base coupling site distant from the link connection; and 
 for each effector transmission element, a transmission clamp connects the effector transmission element to a corresponding base transmission element, thereby coupling the effector transmission element, and thereby its associated link, to a movable terminal of one of the plurality of actuators. 
 
     
     
         74 . The robotic apparatus of  claim 73 , the base linkage further comprising a receptacle for the engagement of a movable counterweight, thereby permitting fine-tuning of counterbalancing the base linkage and the effector unit. 
     
     
         75 . The robotic apparatus of  claim 74 , the receptacle comprising an opening in a link that is in thermal communication with each of the actuators of the actuator set, the apparatus further comprising a counterweight, sized to engage the receptacle, the counterweight including passages to allow the passage of cooling fluid therethrough. 
     
     
         76 . The robotic apparatus of  claim 73 , at least one of the actuators comprising a hydraulic actuator. 
     
     
         77 . The robotic apparatus of  claim 73 , further comprising a controller coupled to the actuators, the controller configured to control the slave according to an Inverse Jacobian controller. 
     
     
         78 . The robotic apparatus of  claim 77 , the Inverse Jacobian controller configured to:
 command at least one of the actuators with micro freedom gains; and   command at least one of the actuators with macro freedom gains that are much larger than the micro freedom gains.   
     
     
         79 . The robotic apparatus of  claim 78 , the macro and micro freedom gains sized such that the ratio of a representative one of the micro freedom gains to a representative one of the macro freedom gains is on the order of a ratio of a representative one of the micro freedom inertias to a representative one of the macro freedom inertias. 
     
     
         80 . The robotic apparatus of  claim 78 , further comprising a master controller configured to control a master device for controlling the robotic apparatus according to a Jacobian Transpose controller; the apparatus further comprising:
 an environment position sensor, arranged to generate a signal that corresponds to the translational position of a reference point in an environment in which the robotic apparatus may reside, the Inverse Jacobian controller further commanding the macro freedom actuators and micro freedom actuators to move the effector in concert with the environment reference point, and the Jacobian Transpose controller further configured to command the master to move a master reference point to follow only motion of the effector reference point that does not correspond to motion of the environment reference point, thereby presenting the effect to a user who is in contact with the master reference point that the effector is interacting with an environment that is substantially motionless.   
     
     
         81 . The apparatus of  claim 80 , the environment position sensor configured to generate a signal that corresponds to the translations of an environment reference point on a beating mammalian heart.