DESIGN OF A SINGULARITY-FREE ARTICULATED ARM SUBASSEMBLY

Adding a redundant degree of freedom to the shoulder pointing system c omplex of an articulated arm subassembly makes it possible to achieve a maximal workspace that is free of singularities. This paper derives a functional constraint between three of the four joints of this new t ype of arm, achieving a singularity-free workspace encompassing the en tire reachable volume between the maximal- and minimal-reach surfaces. The large volume of dexterous workspace is verified by animation of t he resulting arm design. Graphical results from the animation are pres ented comparing the dexterous workspace of this new arm to that of the standard nonredundant articulated arm subassembly such as found in th e Puma manipulator.