Dimensional synthesis of a 2-PRS-PRRU parallel manipulator

Abstract

This paper deals with the dimensional synthesis of a 2-PRS-PRRU (P, R, S and U standing for actuated prismatic, revolute, spherical and universal joint, respectively) parallel manipulator considering both dexterity and motion/force transmission. First, the inverse kinematic analysis of the parallel robot is presented. Next, the reciprocal of the condition number and the global conditioning index (GCI) based on a dimensionally homogeneous Jacobian matrix are used to evaluate the dexterity. Then, local transmission index (LTI) and good transmission workspace (GTW) are used for evaluation of the motion/force transmissibility of the 2-PRS-PRRU parallel manipulator. Finally, considering the GCI and GTW simultaneously, the parameter-finiteness normalization method is used to produce an optimal design. Both dexterity and motion/force transmission can be improved with the optimized link parameters.