A Reduced Order Model Derivation for Lightweight Arms with A Parallel Mechanism

Abstract

RALF (Robotic Arm, Large and Flexible) with a parallel link mechanism has been developed at School of Mechanical Engineering at Georgia Institute of Technology. The structure consists of two ten foot long links and an actuator link which is parallel to the first link and drives the second link. In this paper, a derivation of a reduced order model for RALF by the modal cost analysis methods is shown. The original models are based on the first 5 component modes of each link. Two sets of mode shapes are considered which result from different boundary conditions on the components (links). The reduced order model which consists of the first 2 modes of each link is optimal from the control point of view. The evaluation of the reduced order model is made by the comparison between the frequency responses and the modal cost analysis results.