基于有限元方法的3-PPSR 大长径比柔性并联机器人刚度模型分析

Analysis on Stiffness Model of 3-PPSR Flexible Parallel Robot with High Aspect Ratio Based on Finite Element Method

  • 摘要: 为实现较大工作空间的运动,设计了一种大长径比的3-PPSR 结构的微操作柔性并联机器人.该机器人由压电马达驱动,采用大长径比柔性铰链连接,柔性铰链的变形范围在毫米级,适用于要求大变形的场合,同时具有结构简单、无奇异、无间隙、运动精度高等特点.由于系统的刚度直接影响系统的运动精度、承载负荷等性能,针对大长径比柔性铰链特点,运用有限元方法,建立了柔性铰链的数学模型,并采用整体刚度的方法,结合机构协调方程和力平衡方程,得到系统的柔性刚度模型.最后,采用ANSYS 比较了所建理论刚度模型结果与有限元模型分析的结果.分析结果表明,理论刚度模型合理,符合机构的运动特征.

     

    Abstract: A 3-PPSR flexible parallel robot with high aspect ratio for micromanipulation is designed to achieve a greater workspace. It is driven by a piezoelectric motor, connected by flexible hinges with high aspect ratio, the deformation of which is in the millimeter range, suitable for large deformation. And, it has the advantages of simple structure, non-singular motion, no gap and high motion precision. Because the stiffness of the system directly affects the motion accuracy and the load bearing performance, firstly the mathematical model of flexible hinge is established through finite element method, according to the characteristics of the flexible hinge with high aspect ratio. Then, the flexible stiffness model of system is set up by using the method of integral stiffness and combining coordination equation with force balance equation. Finally, the theoretical stiffness model is compared with the finite element analysis based on ANSYS. The result analysis demonstrates that the stiffness model is valid, and matches with the motion characteristics of the proposed mechanism.

     

/

返回文章
返回