A Proposal of Hand/Eye-Vergence Dual Visual Servoing for Enhancing Trackability

Abstract

Visual servoing with a hand-eye configuration tends to be vulnerable for hand's dynamical oscillations, since nonlinear dynamical effects of whole manipulator and dynamical coupling among actuating joints stand against tracking ability—abbreviated here as trackability, i.e. a performance to keep a target object projected at the center of camera's view while the target moves. A proposal to achieve high trackability is that visual servoing of the hand and the camera be separately controlled independently by decoupling each other, and such controlling method is proposed in this paper. The effectiveness of the decoupled hand and eye-vergence visual servoing method has been evaluated through simulations incorporated with actual dynamics of 7-DoF robot with additional 3-DoF eye-vergence mechanism, where the stability of closed loop dynamics has been verified by Lyapunov analysis.