Systems and methods for facilitating access to edges of cartesian-coordinate space using the null space
AssigneeIntuitive Surgical Operations, Inc.
InventorArjang Hourtash
Life of this patent
Estimating the term…
Abstract
Devices, systems, and methods for providing increased range of movement of the end effector of a manipulator arm having a plurality of joints with redundant degrees of freedom. Methods include defining a position-based constraint within a joint space defined by the at least one joint, determining a movement of the joints along the constraint within a null-space and driving the joints according to a calculated movement to effect the commanded movement while providing an increased end effector range of movement, particularly as one or more joints approach a respective joint limit within the joint space.
Claims31
A robotic method comprising:
- providing a manipulator arm including a movable distal surgical 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;
- defining a position-based constraint of one or more joints within a joint space of the plurality of joints for which increased range of movement is desired;
- receiving a manipulation command to move the end effector with a desired end effector movement;
- calculating an end effector displacing movement of the one or more joints to effect the desired end effector movement, wherein calculating the end effector displacing movement of the joints comprises calculating joint velocities within a null-perpendicular-space of a Jacobian;
- and
- calculating a facilitating movement of a set of joint(s) of the plurality along the position-based constraint, the facilitating movement increasing the available range of movement of the end effector, wherein calculating the facilitating movement comprises calculating joint velocities of the one or more joints within a null-space of the Jacobian, the null-space being orthogonal to the null-perpendicular space;
- and
- driving the joints according to the calculated movements so as to effect the desired end effector movement while providing the increased range of movement of the end effector.
A 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 distal end effector and the proximal portion coupled to the base, the joints providing sufficient degrees of freedom to allow a range of joint states for a given state of the distal end effector;
- an input for receiving a manipulation command to move the end effector with a desired end effector movement;
- and
- a processor coupling the input device to the manipulator arm, the processor configured to:
- calculate an end effector displacing movement of the joints in response to the manipulation command by calculating joint velocities within a null-perpendicular-space of a Jacobian;
- define a position-based constraint of one or more joints of the plurality within an associated joint space, the constraint corresponding to an increased range of movement of the one or more joints;
- calculate a facilitating movement of the one or more joints within a null-space of the Jacobian that moves the one or more joints toward the constraint, the null-space being orthogonal to the null-perpendicular space;
- and
- transmit a command to the manipulator arm to drive the plurality of joints according to the calculated movements so as to effect the desired end effector movement concurrent with the desired movement of the one or more joints.
Dependencies are inferred from the claim text.