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 medical robotic system comprising:
a medical device; a manipulator for manipulating the medical device in at least 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 a controller configured to resolve a control ambiguity caused by the first and third axes coinciding while commanding the manipulator to manipulate the medical device to a commanded state, wherein the controller resolves the control ambiguity by determining whether the commanded state is within an allowed direction defined by a plane of rotation of the second rotational degree of freedom of the manipulator, commanding the manipulator to manipulate the medical device to the commanded state if the commanded state is determined to be in the allowed direction by using the second rotational degree of freedom of the manipulator, and commanding the manipulator to manipulate the medical device to the commanded state if the commanded state is determined not to be in the allowed direction by first changing the allowed direction using the first 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.