CONSTRAINED CARTESIAN MOTION CONTROL FOR TELEOPERATED SURGICAL ROBOTS

This paper addresses the problem of optimal motion control for teleope rated surgical robots, which must maneuver in constrained workspaces, often through a narrow entry portal into the patient's body, The contr ol problem is determining how best to use the available degrees of fre edom of a surgical robot to accomplish a particular task, while respec ting geometric constraints on the work volume, robot mechanism, and th e specific task requirements, We present a method of formulating desir ed motions as sets of task goals in any number of coordinate frames (t ask frames) relevant to the task, optionally subject to additional lin ear constraints in each of the task frames, Mathematically, the kinema tic control problem is posed as a constrained quadratic optimization p roblem and is shown to be computable in real time on a PC, We will pre sent experimental results of the application of this control methodolo gy to both kinematically deficient and kinematically redundant robots, Specifically, we will discuss the control issues within the context o f a representative set of tasks in robot-assisted laparoscopy, which i ncludes (but is not limited to) teleoperated navigation of a laparosco pic camera attached to a surgical robot, A system based on this contro l formalism has been used in preclinical in vivo studies at the Johns Hopkins University Medical Center and the early experience with the sy stem will be summarized.