Optimization of a 6-DOF parallel robotic manipulator based on kinematic performance indexes

Parallel manipulators are well known because of their high dynamic performances and low positioning errors, having attracted great attention from researchers in the last few years. Generally speaking, the performance of a robotic manipulator is highly dependent on its structural configuration. Thus, after its choice, the mechanical structure must be defined, i.e., the set of mechanical parameters defining the structure must be dimensioned. At this stage some performance criterion may be optimized. In this paper the kinematic optimization of a 6-dof parallel robotic manipulator is considered. Since local optimization methods are especially useful when applied to manipulators with small workspaces, or designed to operate over small subsets of their workspaces, several global performance indexes are compared and the resulting manipulator structures are analysed in this paper.