Theory of parallel mechanisms

Abstract

This book contains mechanism analysis and synthesis.In mechanism analysis, a mobility methodology is first systematicallypresented. This methodology, based on the author's screw theory,proposed in 1997, of which the generality and validity was only provedrecently, is a very complex issue, researched by various scientistsover the last 150 years. The principle of kinematic influence coefficientand its latest developments are described. This principle is suitablefor kinematic analysis of various 6-DOF and lower-mobility parallelmanipulators. The singularities are classified by a new point ofview, and progress in position-singularity and orientation-singularityis stated. In addition, the concept of over-determinate input isproposed and a new method of force analysis based on screw theoryis presented.In mechanism synthesis, the synthesis for spatial parallel mechanismsis discussed, and the synthesis method of difficult 4-DOF and 5-DOFsymmetric mechanisms, which was first put forward by the author in2002, is introduced in detail. Besides, the three-order screw systemand its space distribution of the kinematic screws for infinite possiblemotions of lower mobility mechanisms are both analyzed.