Structure Synthesis of 4-DOF (3-Translation and 1-Rotation) Parallel Robot Mechanisms Based on the Units of Single-Opened-Chain

Based on the units of single-opened-chain limb, some topological characteristics of rank-degenerate parallel robot mechanisms are revealed, and a systematic and effective new method for structure synthesis of 4-DOF (3-translation and 1-rotation) parallel robot mechanism is put forward in this paper. 50 new mechanisms are synthesized and classified. The method proposed in this paper is of universal significance and has been used for the structure synthesis of rank-degenerate parallel robot mechanisms with other kinematics output types.