Kinematic performance evaluation of a bioinspired 5-DOF parallel driving mechanism with multi-loop coupled chain

This paper deals with the kinematic performance evaluation of a bioinspired 5-DOF parallel driving mechanism (PDM) PRTU-X5. The PRTU-X5 consists of five open-loop active limbs and one passive hybrid kinematic chain. To tackle the challenge of evaluating the kinematic performance of this 5-DOF PDM with multi-loop coupled kinematic chains, this study presents a divide-and-conquer based evaluation strategy, utilizing the functional sequences and kinematic decoupling to simplify the complex mechanism topology analysis issue into sub-issues of sub-mechanism systems. The local evaluation indices of the sub-mechanisms are derived by integrally utilizing the transmission and interaction performance evaluation criteria. The local comprehensive evaluation index (LCEI) is then defined. Under the guidance of the bionic motion atlas of manual two-arm cooperation, the positioning and orientation capability are evaluated. Finally, the performance maps are plotted to visualize the kinematic performance of the PRTU-X5. The evaluation results show the feasibility and validity of the proposed strategy and indices and provide a foundation for the dimension optimization of the PRTU-X5. This work can serve as a reference for other parallel mechanisms with complex mechanism topology.