A method of stiffness analysis of parallel mechanisms

Abstract

This paper presents a method, called Parameter-Separation Method, for stiffness analysis of parallel mechanisms. By treating the effect of different parameters (i.e. external force and torque, translational and rotational displacement) separately, the method produces 4 criteria of stiffness analysis. A further method based on the first method is proposed when we conduct stiffness analysis on some parallel mechanisms whose inputs are of the same unit. It applies a special way to formulate dimensionally homogeneous Jacobian matrix with consideration of the input need, and comes up with 2 criteria to judge the stiffness of parallel mechanisms. These two methods are explained in detail, and their effects and relationship are demonstrated by stiffness analysis of a 4RRR redundantly actuated parallel mechanism. © 2009 Springer-Verlag Berlin Heidelberg.