Dynamic finite-element analysis of a planar high-speed, high-precision parallel manipulator with flexible links.

摘要

This thesis performs a dynamic finite element analysis of a planar fully parallel robot with flexible links. The governing equations of motion are based on the linear theory of kineto-elastodynamics.; Results show that: (1) Convergence of the responses is achieved when each link is modeled with only one axially extendible high-order beam element, resulting in twelve flexible degrees-of-freedom; (2) The first mode's natural frequency (ω₁) varies significantly with the configuration, from zero Hertz to more than 500 Hertz. A large ω ₁ is associated with stiff configurations and warrants small amplitude dynamic vibrations. In contrast, a low ω₁ can lead to relatively large amplitude vibrations, provided that this mode is excited by the input motion; (3) The additional terms included in the governing equations of motion, namely Coriolis damping, and centrifugal and geometric stiffnesses, have a negligible contribution to the vibratory response in the present analysis.