Evaluation of dexterity measures for a 3-link planar redundant manipulator using constraint locus

This paper describes how to evaluate the performance of dexterity measures by investigating the properties of the inverse kinematic algorithms. These algorithms use redundancy to optimize the dexterity measure under the constraint of following a specified end-effector trajectory. To facilitate the investigation, a concept of the constraint locus is proposed. The constraint locus is the loci of configurations satisfying the necessary conditions for optimality of a dexterity measure in the configuration space. The topological properties of the inverse kinematic algorithm both on the configuration and operation spaces define the invertible workspace without singularities. Using the global properties of two dexterity measures, the authors provide a promising algorithm which provides a singular-free and conservative joint trajectory for tasks occupying almost the entire workspace