Control of medical robotic system manipulator about kinematic singularities

摘要

A medical robotic system includes an entry guide with articulatable instruments extending out of its distal end, an entry guide manipulator providing controllable four degrees-of-freedom movement of the entry guide relative to a remote center, and a controller configured to manage operation of the entry guide manipulator in response to operator manipulation of one or more input devices. As the entry guide manipulator approaches a yaw/roll singularity, the controller modifies its operation to allow continued movement of the entry guide manipulator without commanding excessive joint velocities while maintaining proper orientation of the entry guide.

主权项

1. A method for controlling a manipulator configured to move a medical device in first, second, and third rotational degrees of freedom in which the medical device is respectively rotatable about first, second, and third axes at a pivot point, and for resolving a control ambiguity caused by the first and third axes coinciding, the method comprising:
determining whether a commanded state of the medical device is within an allowed direction defined by a plane of rotation of the second rotational degree of freedom of the manipulator, if the commanded state is determined to be in the allowed direction, then commanding the manipulator to move the medical device to the commanded state by using the second rotational degree of freedom of the manipulator, and if the commanded state is determined not to be in the allowed direction, then commanding the manipulator to move the medical device to the commanded state by first changing the allowed direction using the third rotational degree of freedom so that the commanded state is within the allowed direction and then using the second rotational degree of freedom of the manipulator.