A passive admittance controller to enforce Remote Center of Motion and Tool Spatial constraints with application in hands-on surgical procedures
This work addresses safety and control issues in hands-on surgical procedures, representing an incremental improvement in robotic assistance for surgery.
The paper tackled the problem of restricting manipulator motions in minimally invasive surgery to enforce safe tool manipulation through a remote center of motion and avoid forbidden regions, resulting in a passive admittance controller that ensures stability and smooth motion in experiments with a KUKA LWR4+ setup.
The restriction of feasible motions of a manipulator link constrained to move through an entry port is a common problem in minimum invasive surgery procedures. Additional spatial restrictions are required to ensure the safety of sensitive regions from unintentional damage. In this work, we design a target admittance model that is proved to enforce robot tool manipulation by a human through a remote center of motion and to guarantee that the tool will never enter or touch forbidden regions. The control scheme is proved passive under the exertion of a human force ensuring manipulation stability, and smooth natural motion in hands-on surgical procedures enhancing the user's feeling of control over the task. Its performance is demonstrated by experiments with a setup mimicking a hands-on surgical procedure comprising a KUKA LWR4+ and a virtual intraoperative environment.