Dynamic modeling and analysis of the 3-■RS power head based on the screw theory and rigid multipoint constraints

作者：MA YiWei^*; TIAN YanLing; LIU XianPing; LU ChengHao

来源：Science China Technological Sciences, 2023, 66(07): 1869-1882.

This study presents a dynamic modeling and analysis methodology for the 3-■RS parallel mechanism.First,an improved reduced dynamic model of component substructures is proposed using the dynamic condensation technique and the rigid multipoint constraints at the joint/interface level,leading to a minimum set of generalized coordinates for external nodes.Next,the mapping between interface constraint stiffness and global stiffness is illustrated,resulting in an analytical stiffness model of joint substructures.Subsequently,the derived component and joint substructures are synthesized into the entire mechanism based on the Lagrange equation.Finally,a case study illustrates that the lower-order dynamic performances predicted within the proposed approach have the same trend as those obtained from a complete-order finite element model.The root mean square discrepancy of the lower-order natural frequencies between the two models is less than 5.92%,indicating the accuracy and effectiveness of the proposed model.The developed approach can highly and efficiently predict the dynamic performance distributions across the entire workspace and guide the optimal functional design under the virtual machine framework.

• 单位
  天津大学