Type synthesis for lower-mobility decoupled parallel mechanism with redundant constraints

A novel method for type synthesis of lower-mobility decoupled parallel mechanism with redundant constraints is proposed. Firstly, the definition of the redundant constraints is put forward. Then, number and topology structure synthesis is carried out based on the redundant constraints between the closed loop structure of parallel configuration. Next, the specific procedure for type synthesis of lower-mobility decoupled parallel mechanism is derived. Furthermore, the local freedom of the limbs was established through the relationship of motion-screw and constraint-screw between limbs. Finally, type synthesis of 2R1T decoupled parallel mechanism is established. The synthesized configuration theoretical output characteristics is a decoupled Jacobin matrix. The output characteristics are analyzed based on theoretical calculation and ADAMS simulation software. The simulation results and the theoretical calculation results are consistent. The proposed method can be applied to type synthesis of lower-mobility decoupled parallel mechanisms.