Modeling Effects on Free Vibration of a Two-Link Flexible Manipulator

In this article, the frequency characteristics of a two-link flexible manipulator in an arbitrary position are investigated by using two analytical models. In particular, two formulations based on Euler-Bernoulli beam theory are herein used to derive analytical modal data for different slenderness ratios of robotic manipulators. The comparison between the results stresses that, except for extremely flexible manipulators, appreciable discrepancies can occur; these latter can be attributed to axial vibrations which, are neglected in one model, but are instead introduced in the other as proposed by the present authors. A finite element analysis validates this latter model thus making the authors confident on the ability of the model to provide more accurate results for a larger class of robotic manipulators.