US 12,491,640 B2Granted

Apparatus, computer-implemented method and computer program for enabling the tracking of a robotic instrument to a passive controller

AssigneePrecision Robotics Limited

InventorsMalgorzata Kamedula, Zhang Lin, Jindong Liu

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Abstract

An apparatus including computer program code configured to cause the apparatus to: receive a command defining a desired pose of an end effector of a robotic instrument; determine, based on the command, joint parameters for each joint of the robotic instrument using an inverse kinematics algorithm to enable the end effector to mimic the desired pose as closely as possible, wherein the algorithm is configured to reiteratively calculate a pose of the end effector and identify the calculated pose with the smallest tracking error as a global solution if the tracking error is smaller than that associated with a current pose of the end effector, otherwise identify the current pose as the global solution; and wherein the apparatus is configured to generate a motor command to reconfigure the joints according to the global solution if the calculated pose with the smallest tracking error is identified as the global solution.

Claims18

Dependent claims

An apparatus comprising:

at least one processor;
and
at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus to:
receive a control command from a passive controller, the passive controller configured to remotely control a robotic instrument having a plurality of joints and an end effector, the control command defining a desired pose of the end effector, wherein the passive controller and robotic instrument have freedom of movement within respective control and instrument workspaces, and wherein the control workspace is mapped to the instrument workspace to allow the pose of the robotic instrument to track the pose of the passive controller as the passive controller moves within the control workspace;
determine, based on the control command, a global solution of joint parameters for each of the plurality of joints using an inverse kinematics algorithm to enable the end effector to mimic the desired pose as closely as possible within the instrument workspace, wherein the inverse kinematics algorithm is configured to:
determine one or more position limits of the robotic instrument within the instrument workspace to define one or more position constraints;
calculate an initial tracking error based on the one or more position constraints, a current pose of the end effector, and the desired pose using a first set of joint parameters;
calculate a plurality of tracking errors based on the one or more position constraints, the current pose of the end effector, and the desired pose using a plurality of sets of joint parameters different from the first set of joint parameters;
identify the set of joint parameters associated with the smallest tracking error as the global solution only if the smallest tracking error is smaller than the initial tracking error, otherwise identify the first set of joint parameters as the global solution;
and
wherein the apparatus is further configured to generate a motor command to reconfigure the plurality of joints according to the set of joint parameters associated with the global solution if the smallest tracking error is identified as the global solution.

8 more elements

A computer-implemented method comprising:

receiving a control command from a passive controller, the passive controller configured to remotely control a robotic instrument having a plurality of joints and an end effector, the control command defining a desired pose of the end effector, wherein the passive controller and robotic instrument have freedom of movement within respective control and instrument workspaces, and wherein the control workspace is mapped to the instrument workspace to allow the pose of the robotic instrument to track the pose of the passive controller as the passive controller moves within the control workspace;
determining, based on the control command, a global solution of joint parameters for each of the plurality of joints using an inverse kinematics algorithm to enable the end effector to mimic the desired pose as closely as possible within the instrument workspace, wherein the inverse kinematics algorithm is configured to:
determine one or more position limits of the robotic instrument within the instrument workspace to define one or more position constraints;
calculate an initial tracking error based on the one or more position constraints, a current pose of the end effector, and the desired pose using a first set of joint parameters;
calculate a plurality of tracking errors based on the one or more position constraints, the current pose of the end effector, and the desired pose using a plurality of sets of joint parameters different from the first set of joint parameters;
identify the set of joint parameters associated with the smallest tracking error as the global solution only if the smallest tracking error is smaller than the initial tracking error, otherwise identify the first set of joint parameters as the global solution;
and
wherein the method further comprises generating a motor command to reconfigure the plurality of joints according to the set of joint parameters associated with the global solution if the smallest tracking error is identified as the global solution.

5 more elements

Dependencies are inferred from the claim text.