Study On Some Problems In Constraint Chain Of No-full DOF Parallel Machine Tool

Parallel machine tool, namely so-called parallel robot, has been one successful paradigm that parallel robot technology is applied to manufacturing machine tools. Since GINNINGS&LEWIS Company displayed VARIAS sample on international exMbition in Chicago in September in 1994, it has being obtained comprehensive attention from domestic and alien scholars. In no more than ten years, the research works on parallel machine tools have developed longitudinally to the extent that the technology has attained actual utilization while limited- DOF parallel machine tool is a hotspot of research. The study on limited- DOF parallel machine tool is insufficient in fundamental theory and engineering application.This paper is on the base of national high technology project (863-512-30-07) -technological development in billet thinning robot, and national natural science fund (59875012) - theory research and prototype development on tri-shank robot with six DOF as machine tool. On above basis, configuration DOF and constitution design are studied according to the characteristics of no-full DOF parallel machine tool. Such aspects as the track programming of the movement and simulation, dynamical characteristic and analogue, static analysis and emulation, stiffness analysis and simulation have been investigated deeply and systematically.By investigating inland and outland research status quotation and critical technology, more exhaustive research direction is demonstrated in limited- DOF parallel robot theory and its application domain and the intention and significance on the project are interpreted.By studying the method to construction design and the influence of kinetic restriction of embranchment chain of limited- DOF parallel robot on motive platform DOF, and putting forward the definition on restriction chain and active chain, restriction chain structure and active chain kinematics pair are determined in the light of the DOF of parallel machine tool.Discussing the relation between' respective embranchment chain DOF and joint DOF, and discerning restriction chain construction and active chain embranchment shank joint form, DOF configuration method of no-full DOF parallel machine tool is brought forward.After analyzing kinematics and dynamic character 3-TPT parallel machine tool developed by Northeastern University by its simulation model constructed in ADAMS, kinetic and dynamic curves are obtained. Those break a new path to Robert structure design and dynamic property analysis and resolve visualized motion.By the means of investigation for 3-TPT parallel machine tool developed by...