• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2015, Vol. 51 ›› Issue (23): 28-35.doi: 10.3901/JME.2015.23.028

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Kinematic and Stiffness Analysis of Lower-mobility Parallel Mechanisms Based on QR Decomposition

WANG Chang1,2,  ZHAO Tieshi1,2,  ZHAO Yanzhi1,2,  GENG Mingchao1,2,  LI Erwei1,2   

  1. 1. Hebei Provincial Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University, Qinhuangdao 066004;
    2. Key Laboratory of Advanced Forging & Stamping Technology and Science (Yanshan University), Ministry of Education of China, Qinhuangdao 066004
  • Received:2014-12-20 Revised:2015-08-10 Online:2015-12-05 Published:2015-12-05

Abstract: A method to build the kinematic of lower-mobility parallel mechanism is mentioned based on the matrix QR decomposition. The forward and inverse kinematic model is built based on the first and second order influence matrix. The velocity and acceleration constraint matrix are also built. Based on the principle of virtual work, the flexibility matrix and directional stiffness are built. The coupling kinematic of the 3RPS mechanism is analyzed. The directional stiffness of 3RPS is analyzed to verify the structural constraint, and the directional stiffness is visually describes by the distribution of spherical coordinates.

Key words: kinematic, lower-mobility parallel mechanisms, QR decomposition, stiffness