Structural Analysis And Synthesis Of Parallel Metamorphic Mechanism

The parallel metamorphic mechanism is the combination of parallel mechanism and the metamorphic mechanism. During different motion stages of the parallel mechanism, the degree of freedom and motion pattern can be changed, by changing configuration of the metamorphic mechanism.As a result, variable functions can be realized.Firstly, for the feature that the configuration of the single working stage of parallel metamorphic mechanism is the same as that of the parallel mechanism, the methods and steps of structural analysis of single working stage parallel metamorphic mechanism are summarized. Based on the description of the adjacency matrix of the metamorphic mechanism, screw adjacency matrix of single kinematic chain is proposed, which help reduce useless information. At the same time, it improves the information of the connection relation of adjacency matrix, and helps to analyze and describe the parallel metamorphic mechanism. Then, the screw theory is combined with the screw adjacency matrix and the 2-PRRR(R) parallel metamorphic mechanism is used as an example to analyze.Secondly, as for the effects of the configuration changes on the associated motion of parallel metamorphic mechanism, associated motion is analyzed based on the 3-(R)PS parallel metamorphic mechanism. By changing the configuration of the parallel metamorphic mechanism, under the premise of satisfying the same motion pattern, part of the associated motion is eliminated to improve the motion performance.Finally, the mechanism of parallel metamorphic mechanism is classified according to the nature of parallel metamorphic mechanism:constrained direction change, constraint quantity change, constraint type change, and single metamorphic kinematic chains are obtained. Finally,three kinds of parallel metamorphic mechanisms, 3-(R)PS, 2-PRRR(R) and 3-PRP(U), are integrated out which can transform a variety of degrees of freedom and motion patterns.