Method of constrained Cartesian control of robotic mechanisms with active and passive joints

Claim 1

A method of controlling a surgical robot mechanism having one or more active joints and one or more passive joints, where motion of said passive joints is constrained by one or more environmental constraints imposed on the mechanism, the method comprising the steps of: a. determining positions of said active joints and said passive joints of the mechanism; b. determining an actual pose of a target element; c. determining a pose difference between the actual pose and a desired pose of the target element; d. on a first iteration of the method, characterizing said environmental constraints on a motion of said passive joints, said environmental constraints comprising a surgical opening in a patient's body; e. Jacobian mapping effects of said environmental constraints, a motion of said active joints, and the motion of said passive joints on motion of the target element; f. characterizing a desired incremental motion of the target element; g. using the Jacobian mapping of the effects of said environmental constraints on the motion of said passive joints to determine an incremental active joint motion for each of said active joints, the incremental active joint motion producing an actual incremental motion of the target element, so that a difference between the desired incremental motion and the actual incremental motion of the target element is minimized; h. moving said active joints by the determined incremental active joint motion; and i. repeating steps a through h until the pose difference between the actual pose and the desired pose of the target element is less than a desired amount.

Claim 2

A method of controlling a surgical robot mechanism having one or more active joints and one or more passive joints, where motion of said passive joints is constrained by one or more environmental constraints imposed on the mechanism, the method comprising the steps of: a. determining positions of said active joints and said passive joints of the mechanism; b. determining an actual pose of a target element; c. determining a pose difference between the actual pose and a desired pose of the target element; d. on a first iteration of the method, characterizing said environmental constraints on a motion of said passive joints, said environmental constraints comprising a surgical opening in a patient's body; e. Jacobian mapping effects of said environmental constraints, a motion of said active joints, and the motion of said passive joints on motion of the target element; f. characterizing a desired incremental motion of the target element; g. using the Jacobian mapping of the effects of said environmental constraints on the motion of said passive joints to determine an incremental active joint motion for each of said active joints, the incremental active joint motion producing an actual incremental motion of the target element, so that a difference between the desired incremental motion and the actual incremental motion of the target element is minimized; h. moving said active joints by the determined incremental active joint motion; and i. repeating steps a through h until the pose difference between the actual pose and the desired pose of the target element is less than a desired amount.

Claim 6

A method of controlling a surgical robotic mechanism comprising a plurality of active joints and passive joints, the method comprising the steps of: a. determining positions of all of said active and passive joints of the mechanism; b. determining an actual pose of a target said element being rigidly attached at a distal end of said mechanism; c. determining a pose difference between the actual pose and a desired pose of the target element; d. on the first iteration, characterizing an environmental constraint on motion of the passive joints and imposing one or more task constraints on motion of the active joints of the mechanism, and on subsequent iterations using an actual incremental motion of the target element to update the characterization of the environmental constraint on the motion of the passive joints, said environmental constraint comprising a surgical opening in a patient's body; e. Jacobian mapping the effects of the environmental constraint, the motion of the active joints, and the motion of the passive joints on the motion of the target element; f. characterizing a desired incremental motion of the target element; g. using the Jacobian mapping of the effects of the environmental constraint on the motion of the passive joints and using the task constraints on the motion of the active joints to determine an incremental active joint motion for each of said active joints, the incremental active joint motions producing an actual incremental motion of the target element, so that the difference between the desired incremental motion and the actual incremental motion is minimized; h. moving the active joints by the determined incremental active joint motion, respectively; and i. repeating steps a through h until the pose difference between the actual and the desired pose of the target element is less than a desired amount.

Claim 7

A method of controlling a surgical robotic mechanism comprising a plurality of active joints and passive joints, the method comprising the steps of: a. determining positions of all of said active and passive joints of the mechanism; b. determining an actual pose of a target said element being rigidly attached at a distal end of said mechanism; c. determining a pose difference between the actual pose and a desired pose of the target element; d. on the first iteration, characterizing an environmental constraint on motion of the passive joints and imposing one or more task constraints on motion of the active joints of the mechanism, and on subsequent iterations using an actual incremental motion of the target element to update the characterization of the environmental constraint on the motion of the passive joints, said environmental constraint comprising a surgical opening in a patient's body; e. Jacobian mapping the effects of the environmental constraint, the motion of the active joints, and the motion of the passive joints on the motion of the target element; f. characterizing a desired incremental motion of the target element; g. using the Jacobian mapping of the effects of the environmental constraint on the motion of the passive joints and using the task constraints on the motion of the active joints to determine an incremental active joint motion for each of said active joints, the incremental active joint motions producing an actual incremental motion of the target element, so that the difference between the desired incremental motion and the actual incremental motion is minimized; h. moving the active joints by the determined incremental active joint motion, respectively; and i. repeating steps a through h until the pose difference between the actual and the desired pose of the target element is less than a desired amount.

Claim 10

A method for controlling a surgical robot, constrained by a surgical opening, said surgical robot comprising both active and passive joints, comprising steps of: quantifying constraints of a surgical opening in a body undergoing a surgical operation on said active joints and said passive joints; quantifying current positions of said active joints and said passive joints; quantifying an actual position of a target element using said current positions of said active joints and said passive joints; quantifying a desired position for said target element; calculating a Jacobian using said quantified constraints of the surgical opening in the body undergoing a surgical operation relating velocities in active joint space and passive joint space to velocities in Cartesian space for an incremental movement between said actual position and said desired position; and moving said active joints according to said Jacobian such that said surgical opening is undisturbed.

Claim 11

A method for controlling a surgical robot, constrained by a surgical opening, said surgical robot comprising both active and passive joints, comprising steps of: quantifying constraints of a surgical opening in a body undergoing a surgical operation on said active joints and said passive joints; quantifying current positions of said active joints and said passive joints; quantifying an actual position of a target element using said current positions of said active joints and said passive joints; quantifying a desired position for said target element; calculating a Jacobian using said quantified constraints of the surgical opening in the body undergoing a surgical operation relating velocities in active joint space and passive joint space to velocities in Cartesian space for an incremental movement between said actual position and said desired position; and moving said active joints according to said Jacobian such that said surgical opening is undisturbed.