Systems and methods for tracking a path using the null-space

A method for moving a manipulator assembly that is adapted to support a tool that includes a tool tip, the manipulator assembly comprising a proximal portion coupled to a base, and a plurality of joints between the tool tip and the base, the plurality of joints having sufficient degrees of freedom to allow a range of differing joint states for a given state of the tool tip, and the method comprising:

• defining a position-based constraint of one or more joints of the plurality of joints within a joint space of the plurality of joints, the position-based constraint including one or more paths corresponding to a desired movement of the one or more joints within the joint space of the plurality of joints;
• calculating a tracking movement of the plurality of joints so as to move one or more positions of the one or more joints of the plurality of joints towards the position-based constraint, wherein calculating the tracking movement of the plurality of joints comprises calculating joint velocities of the plurality of joints from joint-velocity directions that correspond to the tool tip not moving;
• and
• driving the plurality of joints according to the calculated tracking movement.

A system comprising:

• a manipulator assembly that is adapted to support a tool that includes a tool tip, the manipulator assembly comprising a proximal portion coupled to a base, and a plurality of joints between the tool tip and the base, the plurality of joints having sufficient degrees of freedom to allow a range of differing joint states for a given state of the tool tip;
• one or more processors operably connected to the manipulator assembly, the one or more processors being configured to perform operations including:
• defining a position-based constraint of one or more joints of the plurality of joints within a joint space of the plurality of joints, the position-based constraint including one or more paths corresponding to a desired movement of the one or more joints within the joint space of the plurality of joints;
• calculating a tracking movement of the plurality of joints so as to move one or more positions of the one or more joints of the plurality of joints towards the position-based constraint, wherein calculating the tracking movement of the plurality of joints comprises calculating joint velocities of the plurality of joints from joint-velocity directions that correspond to the tool tip not moving;
• and
• causing the manipulator assembly to drive the plurality of joints according to the calculated tracking movement.

A non-transitory readable memory storing a processor-implemented program for moving a manipulator assembly that is adapted to support a tool that includes a tool tip, the manipulator assembly comprising a proximal portion coupled to a base, and a plurality of joints between the tool tip and the base, the plurality of joints having sufficient degrees of freedom to allow a range of differing joint states for a given state of the tool tip, and the processor-implemented program including instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• defining a position-based constraint of one or more joints of the plurality of joints within a joint space of the plurality of joints, the position-based constraint including one or more paths corresponding to a desired movement of the one or more joints within the joint space of the plurality of joints;
• calculating a tracking movement of the plurality of joints so as to move one or more positions of the one or more joints of the plurality of joints towards the position-based constraint, wherein calculating the tracking movement of the plurality of joints comprises calculating joint velocities of the plurality of joints from joint-velocity directions that correspond to the tool tip not moving;
• and
• driving the plurality of joints according to the calculated tracking movement.