• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2018, Vol. 54 ›› Issue (11): 151-160.doi: 10.3901/JME.2018.11.151

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Kinematics Analysis of a Novel 3T1R Parallel Manipulator with Full Rotational Capability

HE Leiying, TU Yekai, YE Wei, LI Qinchuan   

  1. Department of Mechanical and Electronic Engineering, Zhejiang Sci-Tech University, Hangzhou 310018
  • Received:2017-05-27 Revised:2017-10-18 Online:2018-06-05 Published:2018-06-05

Abstract: Parallel mechanisms (PMs) with 3T1R motion can be applied in many industrial fields. However, most of 3T1R PMs have a range of rotation less than 90°. A novel 3T1R PM with full rotational capability is proposed. The mechanism contains two identical (PRR)2RH hybrid limbs, each consists of a closed-loop subchain and a serial subchain. The full rotational capability is achieved by using two coaxial helical (H) joints with equal but opposite pitch connected to the moving platform. The mobility of 2-(PRR)2RH PM is analyzed based on Lie group theory, followed by the inverse and direct position solutions. The Jacobian matrix is derived based on velocity analysis, and singularity analysis is conducted to find all the singular configurations. Taking the condition number as the index, the performance distribution of the PM in the workspace is sketched. The results will provide theoretical foundations for further researches on the mechanism regarding optimal design and dynamic modeling.

Key words: full rotational capability, parallel manipulator, singularity, workspace

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