A Heuristic Study of Relegation of Control in Constrained Robotic Systems

Abstract

A major control problem in the robotic field is the simultaneous and independent control of constrained trajectories and forces of constraint. The trajectories and the forces are related through the mechanical structure of the system. The task of the controller is to influence the mechanical coupling and allow separate control of the trajectories and the forces. A feasible control strategy is by relegation of control to the state or to the input. Relegation by inputs implies assigning the control of trajectories and forces to independent groups of inputs. In this paper, exact and approximate input relegation strategies are investigated. The effectiveness of the input relegation strategy is tested by digital computer simulation of a three link planar robot in a periodic rubbing maneuver.