Three 2-DOF 1T1R and One 3-DOF 2T1R Full-Hinged Novel Parallel Mechanisms With Zero Coupling Degree and Motion Decoupling: Design and Analysis

Abstract

This paper presents the design and analysis of a family of full-hinged partially-decoupled novel parallel mechanisms (PMs) featuring one/two translation(s) and one rotation (1T1R/2T1R). First, three 2DOF 1T1R and one 3DOF 2T1R novel spatial PMs are proposed, according to topology design theory of PM based on position and orientation characteristic (POC) equations. The 3DOF 2T1R PM is illustrated to show its topological characteristics, such as POC set, degrees-of-freedom (DOF), and coupling degree (k), which show that the PM does not produce parasitic motion, with the coupling degree k being equal to zero. Second, the kinematic and dynamic performances of the 3DOF 2T1R PM are analyzed, including symbolic forward position solutions based on its topological characteristics, the workspace based on both the forward and inverse position solutions, respectively, the singular configurations based on the inverse position solutions, and the dynamic analysis built by means of the virtual work principle based on the single-open-chain units. Finally, the potential application of the proposed 3DOF 2T1R PM, namely, lifting and transferring lightweight workpieces between two perpendicular conveyor belts on the floor, is introduced.