Configuration Synthesis Method of Multi-Mode Parallel Mechanism Based on Variable Mobility Branch

In order to obtain more configurations of multi-mode parallel mechanism with the expected motion modes, a new configuration synthesis method of multi-mode parallel mechanism is proposed in this paper. The generation principle of parallel mechanism with multiple motion modes is analyzed. The relation between the motion of moving platform and the motion of branch is obtained. The finite motion and instantaneous motion of existing variable mobility branches are analyzed, and variable mobility branches are decomposed into variable mobility generators. By using variable mobility generators to construct variable mobility branches, a configuration synthesis method of multi-mode parallel mechanism based on variable mobility branch is proposed. Taking the multi-mode parallel mechanism with 2T1R and 2R1T motion modes as an example, a new class of multi-mode parallel mechanisms are obtained. The proposed method enriches the configuration synthesis theory of multi-mode parallel mechanism and the synthesis results enrich the configurations of multi-mode parallel mechanism.