Solving contact and grasp uncertainties

Abstract

This paper extends previous work on (suboptimal) Kalman filter based identification of geometric uncertainties that occur during the manipulation of an object in contact with its environment. The setup consists of a force-controlled robot which has grasped a cylindrical peg; the relative position and orientation of the peg with respect to the robot end effector are only approximately known. The peg is moved over a surface, whose position and orientation are also uncertain. This paper describes how to estimate the above-mentioned uncertainties, even if some of the geometric uncertainties are instantaneously indeterminate, i.e., their influences on the force and/or velocity errors are instantaneously indistinguishable. Experimental results illustrate the theoretical background of the estimation problem.