System and methods for positioning a manipulator arm by clutching within a null-perpendicular space concurrent with null-space movement

A robotic method comprising:

• providing a manipulator arm including a movable distal end effector, a proximal portion coupled to a base, and a plurality of joints between the end effector and the base, the plurality of joints having sufficient degrees of freedom to allow a range of differing joint states for a given end effector state within a surgical work space, wherein the end effector comprises an instrument shaft that pivots about a remote center adjacent a minimally invasive aperture within the work space during a surgical procedure;
• floating a first set of joints of the plurality of joints within a null-perpendicular space of a Jacobian, wherein the null-perpendicular space is a joint velocity space in which movement of the first set of joints results in movement of the distal end effector within the work space;
• driving the plurality of joints so as to maintain the remote center at a controlled position in the work space;
• sensing a manual backdriving movement of the distal end effector to a desired position within the work space;
• calculating an auxiliary movement of a second set of the plurality of joints to effect a desired movement of the manipulator arm, wherein calculating the auxiliary movement comprises calculating joint velocities of the second set of joints within a null-space of the Jacobian, the null-space being orthogonal to the null-perpendicular space, wherein the null-space is a joint velocity space in which joint movement maintains the state of the end effector;
• and
• driving the second set of joints according to the calculated auxiliary movement concurrent with maintaining the position of the remote center and the desired movement of the manipulator arm.

A robotic method comprising:

• providing a manipulator arm including a movable distal end effector, a proximal portion coupled to a base, and a plurality of joints between the end effector and the base, the plurality of joints having sufficient degrees of freedom to allow a range of differing joint states for a given end effector state, wherein the distal end effector comprises an instrument shaft that pivots about a remote center adjacent a minimally invasive aperture within a surgical work space during a surgical procedure;
• floating a first set of the plurality of joints within a null-perpendicular space of a Jacobian, wherein the null-perpendicular space is a joint velocity sub-space in which movement of the joints results in movement of the remote center within the work space;
• driving the plurality of joints so as to maintain a controlled position of the end effector within the work space;
• sensing a manual backdriving movement of the remote center to a desired location within the work space;
• calculating an auxiliary movement of a second set of the plurality of joints to effect a desired movement of the manipulator arm, wherein calculating the auxiliary movement comprises calculating joint velocities of the second set of joints within a null-space of the Jacobian, the null-space being orthogonal to the null-perpendicular space, wherein the null-space is a joint velocity space in which joint movement maintains a state of the distal end effector;
• and
• driving the second set of joints according to the calculated auxiliary movement during floating of the first set of joints concurrent with maintaining the controlled position of the end effector and the desired movement of the manipulator arm.

A robotic method comprising:

• providing a manipulator arm including a movable distal end effector, a proximal portion coupled to a base, and a plurality of joints between the end effector and the base, the plurality of joints having sufficient degrees of freedom to allow a range of differing joint states for a given end effector state within a surgical work space, wherein the end effector comprises an instrument shaft that pivots about a remote center adjacent a minimally invasive aperture within the work space during a surgical procedure;
• floating a first set of joints of the plurality of joints within a null-perpendicular space of a Jacobian, wherein the null-perpendicular space is a joint velocity sub-space in which joint movement results in movement of both a position of the distal end effector and a location of the remote center within the work space;
• sensing manual backdriving movement of the end effector to a desired position within the work space and movement of the remote center to a desired location within the work space;
• calculating an auxiliary movement of a second set of joints of the plurality of joints to effect a desired state or movement of the manipulator arm, wherein calculating the auxiliary movement comprises calculating joint velocities of the second set of joints within a null-space of the Jacobian, the null-space being orthogonal to the null-perpendicular space, wherein the null-space is a joint velocity sub-space in which movement of the second set of joints maintains a state of the end effector and the remote center;
• and
• driving the second set of joints according to the calculated auxiliary movement while floating the first set of joints so as to allow manual backdriving movement of both the distal end effector and remote center to a desired position and location, respectively, within the work space concurrent with the desired state or movement of the manipulator arm.

A robotic system comprising:

• a manipulator arm configured for robotically moving a distal end effector relative to a proximal base, the manipulator arm having a plurality of joints between the end effector and a proximal portion coupled to the base, the plurality of joints having sufficient degrees of freedom to allow a range of differing joint states for a given end effector state within a surgical work space, wherein the end effector comprises an instrument shaft that pivots about a remote center adjacent a minimally invasive aperture within the work space during a surgical procedure;
• an input for receiving a manipulation command to effect a desired tissue manipulation movement of the end effector;
• and
• a processor coupling the input to the manipulator arm, comprising a manipulation mode and a clutch mode,
• the processor in the manipulation mode configured to calculate joint movements to provide the desired end effector movement in response to the manipulation command,
• the processor in the clutch mode configured to:
• float a first set of joints of the plurality of joints within a null-perpendicular space of a Jacobian to allow manual backdriving movement of the end effector to a desired position within the work space, wherein the null-perpendicular space is a joint velocity sub-space in which movement of the joints results in movement of the end effector;
• calculate an auxiliary movement of a second set of joints of the plurality of joints to effect a desired movement of the manipulator arm, wherein calculating the auxiliary movement comprises calculating joint velocities of the second set of joints within a null-space of the Jacobian, the null-space being orthogonal to the null-perpendicular space;
• and
• drive the second set of joints according to the calculated auxiliary movement concurrent with floating of the first set of joints.

A robotic system comprising:

• a manipulator arm configured for robotically moving a distal end effector relative to a proximal base, the manipulator arm having a plurality of joints between the end effector and a proximal portion coupled to the base, the plurality of joints having sufficient degrees of freedom to allow a range of differing joint states for a given end effector state within a surgical work space, wherein the end effector comprises an instrument shaft that pivots about a remote center adjacent a minimally invasive aperture within the work space during a surgical procedure;
• an input for receiving a manipulation command to effect a desired manipulation movement of the end effector;
• and
• a processor coupling the input to the manipulator arm, the processor configured to with a manipulation mode and a clutch mode,
• the processor in the manipulation mode configured to calculate movement of the joints in response to the command so as to move the end effector with the desired manipulation movement, and
• the processor in the clutch mode configured to:
• float a first set of joints of the plurality of joints within a null-perpendicular space of a Jacobian to allow manual backdriving movement of the end effector and/or an associated remote center about which the end effector pivots, wherein the null-perpendicular space is a joint velocity sub-space in which movement of the first set of joints results in movement of the end effector and/or the remote center within the work space;
• calculate an auxiliary movement of a second set of joints of the plurality of joints to effect a desired movement of the manipulator arm, wherein calculating the auxiliary movement comprises calculating joint velocities of the second set of joints within a null-space of the Jacobian, the null-space being orthogonal to the null-perpendicular space, wherein the null-space is a joint velocity sub-space in which joint movement maintains the state of the end effector and/or associated remote center;
• and
• drive the second set of joints according to the calculated auxiliary movement concurrent with the desired movement of the end effector and/or associated remote center.