New performance indices for 6-dof UPS and 3-dof RPR parallel manipulators

Abstract

In this paper we introduce two new posture-dependent performance indices for 6-dof UPS and 3-dof RPR parallel manipulators. One is based on an object-oriented metric in the workspace (end-effector dependent) and the other one takes the angular velocities of the passive joints into consideration (end-effector independent). Both newly defined indices are invariant under rigid-body motions and similarities, they have a geometric meaning, and they can be computed in real time. Moreover these indices can also be used for robot design, especially the end-effector independent index is suited for that problem by taking the geometry of the manipulator into consideration. We also optimize the design of 6-dof UPS and 3-dof RPR parallel manipulators with respect to both newly presented indices.

Improving Dynamic Performance of Stewart Platforms through Optimal Design Based on Evolutionary Multi-objective Optimization Algorithms

“…Nawratil proposed two new performance indices: an endeffector dependent index defined through operation ellipsoid and an end-effector independent index called control number (CTN). Optimal designs of 6-DoF and 3-DoF parallel manipulators are investigated based on the newly defined indices [8]. Jiang investigated the optimal design of generalized Gough-Stewart platforms based on an analytical dynamic isotropy measure proposed from the inverse mass matrix in joint space [9].…”

Dynamic Modeling and Performance Analysis of a 3-DOF Pan Mechanism for a Cooking Robot#

“…There have been various kinds of kinematic performance indices, including the manipulability measure (Hong and Kim, 2000;Mansouri and Ouali, 2009), the condition number (Nawratil, 2009), the dexterity index (Angeles and LopezCajun, 1992;Li and Xu, 2007), and the global performance index (Liu et al, 2006). Compared with the kinematic performance indices, the dynamic performance index is seldom studied.…”