Research on conceptual design,modeling and control of a novel planar 2-DOF parallel mechanism

FENG Shishun; ZHANG Junpeng; LIANG Dong; CHANG Boyan

doi:10.16578/j.issn.1004.2539.2026.04.004

Abstract：[Objective]To meet the demand for high-speed and compact automated equipment in scenarios such as logistics sorting and food handling,a novel planar 2-degree-of-freedom(2-DOF)parallel robot was designed and proposed to provide a reference for its engineering application through systematic configuration design and performance verification.[Methods]Firstly,based on a heuristic strategy,two new configurations,2-PUU-D and 2-PUU-R,were derived from a 3-PUU mechanism.The 2-PUU-R configuration with better symmetry was selected for in-depth study.Secondly,its forward and inverse position solutions were established using the closed-loop vector method,and the velocity and acceleration mapping relations between components and the end-effector were derived.Then,a simplified rigid-body dynamic model of the system was constructed based on the principle of virtual work,and its accuracy was verified via multi-body dynamic simulation using Simscape software.Finally,a nonlinear computed torque control(NCTC)strategy based on a back propagation(BP)neural network was proposed.A control model was built in the Simulink software environment,and comparative simulation was conducted against the traditional computed torque control(CTC).[Results]The dynamic model verification results show that the error between the theoretically calculated and simulated maximum driving force of the branch chains is less than 2.5 N,confirming the reliability of the model.The control simulation results indicate that the trajectory tracking error of the proposed BP-NCTC strategy reaches the order of 10-4 m,which is one order of magnitude more precise than that of the traditional CTC(10-3 m),demonstrating the superiority of the proposed strategy.The robot takes 0.365 9 s to complete"pick-and-place"operation.With a reasonable structural layout,it can effectively meet the requirements of high precision and high efficiency in industrial production.