Throwing Motion Control of the Pendubot via Unstable Zero Dynamics

Abstract

This paper describes a control strategy for throwing motion of the Pendubot based on the concept of unstable zero dynamics. An underactuated two-link planar robot called the Pendubot is investigated to realize dexterous actions of the superior limb in human throwing motion. In the proposed control strategy, the zero dynamics is intentionally unstabilized when the end-effector of the Pendubot is constrained on a geometric path via output zeroing control. Numerical simulations and experimental results confirm the effectiveness of the proposed control strategy.