Research On Structure And Performance Of Variable Topology Parallel Robot Mechanism

Variable topology parallel mechanisms have similar topology structures and dissimiliar characteristics. Further research for the variable topology parallel mechanism is not only good for the synthesis of novel parallel mechanisms, but also help to promote the ratio of efficient types and practicability. This dissertation systematically deals with the changing topology ways, discusses the influences of structure parameters on the performances, makes the contrasts between the topology structures changed fore and after followed by the application of variable topology mechanisms.Firstly, the strict mathematical definitions of configuration variable topology mechanism (metamorphic mechanism) and type variable topology mechanism were given respectively based on the study of essences and basic changing topology ways of variable mechanism, and carried on analysis with some examples. Thus, the theory system of variable topology mechanism was further perfected. The changing topology ways of planar and spatial parallel mechanisms were put forward respectively with the analysis of some examples on typical planar and spatial parallel mechanisms. At last, a large number of novel variable types were created.Secondly, the constraint features, position formulations, singularities and workspace of 4-TPT and 4-PTT parallel mechanisms were analyzed roundly according to the research of types followed by a novel method for the three diamensional decription of workspace on the basis of LabVIEW softwware. And it was analyzed that the influences of structure parameters on the performances, followed by contrasts between the topology structures changed fore and after. All the above provided a stable basis for type select.Thirdly, based on the Kinematic Jacobian and Force Jacobian matrixes, this paper analyzed the peripheral velocity and angular velocity transmission capacity index, force and moment transmission capacity index. Furthermore, the four performance atlases were plotted. Verifications of influences of topology structures on the dexterity of parallel mechanisms were good for paractical applications of 4-TPT and 4-PTT parallel mechanisms.Fourthly, according as all the above and contracture characteristics of 4-TPT and 4-PTT parallel mechanisms, the applications have been explored meaningfully. The kinematic capacity and kinemic capacity of both of the mechanisms were simulated followed by comparisons and verifications of capacity analysis.Through above analysis and studies, there was a stable foundation for the creative design of mechanism types as well as design and application of parallel robot system with the theoretic perfection and influences of topology structure parameters on performances of variable topology mechanism.