魚型遊泳ロボットの設計に向けた水中における飛び移り座屈の周波数特性解析

抄録

Focusing on the highly maneuverable underwater motions unique to fishes, such as rapid turning and acceleration, we have studied fish type robots using snap-through buckling. In this paper, frequency characteristics of snap-through buckling in water are measured in order to provide a quantitative index for the design of a fish type robot using snap-through buckling. We proposed a mechanism for generating continuous and high frequency snap-through buckling using a scotch yoke mechanism, and developed an experimental system using the mechanism. The motion of the tail fin in water due to snap-through buckling was measured using the elastic body width and deflection length as parameters, and Bode plots were created for each condition. From the experimental results, it was quantitatively shown that there was a frequency characteristic of decreasing gain in the high-frequency range when snap-through buckling occurred in water. The frequency where the gain begins to decrease was approximated as the breaking point frequency, and it was found that the breaking point frequency was higher for larger elastic bodies and lower for larger deflection lengths.