Topological design and analysis of a novel 2T1R parallel mechanism with symbolic position solutions and motion decoupling

GUO Yue; LI Ju; SHEN Huiping

doi:10.16578/j.issn.1004.2539.2025.09.005

Abstract：[Objective]The two-translation-one-rotation(2T1R)parallel mechanism shows good engineering application potential due to its simple structure and low cost,but the current research on new 2T1R mechanism configurations lags behind,contrasting sharply with the research enthusiasm for 1T2R mechanisms.To fill the research gap of 2T1R parallel mechanisms,a pure lower-pair constructed 2T1R parallel mechanism was designed based on the theory of position and orientation characteristic(POC)set to meet the diversified requirements of engineering applications for mechanism performance.[Methods]Firstly,the topological structure of the mechanism was systematically analyzed using topological analysis methods,and key topological features were extracted.Then,a kinematic model was constructed based on topological features,and symbolic forward and inverse position solutions of the mechanism were derived,followed by solving the velocity and acceleration of the moving platform.On this basis,the geometric parameters of the workspace and singular configurations of the mechanism were determined through theoretical analysis.The driving force variation law of the mechanism was solved by means of dynamic modeling.Finally,the conceptual design of the mechanism was completed in combination with practical application scenarios.[Results]The study shows that the pure lower-pair 2T1R parallel mechanism not only has the characteristic of symbolic forward position solution,but also can realize partial motion decoupling with excellent dynamic performance.Meanwhile,its advantages of low cost and large operation space are significant,providing reference and practical guidance for subsequent mechanism optimization design and engineering application.