Papers by Author: Xue Liang Cui

Abstract: Analysis on the singularity of the 3-RPS parallel machine which probably occurs in the engineering application is presented. The influence of the singular configurations in the workspace of the parallel machine is interpreted. To improve the orientation capacity of the moving platform, a novel complex spherical joint is designed, however a special singularity namely coaxial singularity is resulted in. By optimizing the dimension parameters and designing a special moving platform, the singularity can be averted in the wanted workspace, and the nutation angle of the parallel machine can be enlarged to ±45 degree.

Abstract: Based on the screw theory, the force analysis of the 3-RPS parallel machine is illuminated. Been equivalent to a 6-chain parallel machine, the deformation harmony equation of the parallel machine under the outside generalized force is interpreted. The instantaneous stiffness model of the parallel machine, which includes the change of the force Jacobian matrix, is established. Considering the deviation of the position and orientation of the moving platform, which is resulted from the distortion of the PRS chains of the parallel machine, the influence of the change of the Jacobian matrix to the instantaneous stiffness model of the 3-RPS parallel machine is analyzed, and furthermore, it is verified with an instance.