Human-robot interaction via the transfer of power and information signals

Constrained motion in a class of human-controlled robotic manipulators called extenders is discussed. Extenders are defined as a class of robot manipulators worn by humans to increase mechanical strength while the wearer's intellect remains the central control system for manipulating the extender. The human, in physical contact with the extender, exchanges power and information signals with the extender. The present analysis focuses on the dynamics and control of human-robot interaction in the sense of the transfer of power and information signals. General models for the human, the extender, and the interaction between the human and extender are developed. The stability of the system of human, extender, and the object being manipulated is analyzed, and the conditions for stable maneuvers are derived. An expression for the extender performance is defined to quantify the force augmentation. The trade-off between stability and performance is described. The theoretical predictions are verified experimentally