论文标题

通过利用不对称的多稳态来对折纸的动态折叠

Dynamic Folding of Origami By Exploiting Asymmetric Multi-Stability

论文作者

Sadeghi, Sahand, Li, Suyi

论文摘要

在这项研究中,我们通过利用共振激发,不对称的多稳定性和主动控制的结合来检查快速且可逆的折叠方法。潜在的想法是,通过在其共振频率上谐音激发多稳定的折纸,人们可以在其不同稳定的平衡之间迅速折叠,而无需使用响应式材料。为此,我们将双稳定的水炸弹底座作为原型例子。通过基于新的动态模型和实验测试的数值仿真,我们表明了水炸弹双稳定性的固有不对称性可以使动态折叠具有相对较低的驱动要求。例如,如果水炸弹最初定居其“弱”稳定状态,则可以使用碱基激发来诱导孔内的共振。结果,即使激发没有停止,折纸也会折叠并保持在另一个“强”稳定状态。另一方面,从强度开始的折纸动态更为复杂。由于动态折叠行为,不对称的势能屏障,共振频率的差异和激发振幅之间的非线性关系,水炸弹折纸容易显示出孔间振荡,而不是单向开关。因此,我们制定了一种主动反馈控制策略,该策略在关键时刻切断了基本激发输入,以实现从强稳定状态到弱状态的稳健和单向折叠。这项研究的结果可以适用于许多不同种类的折纸,并为快速和可逆的(自我)折叠创建一种新方法,从而推进了折纸在形状变形系统,适应性结构和可重新配置的机器人技术中的应用。

In this study, we examine a rapid and reversible origami folding method by exploiting a combination of resonance excitation, asymmetric multi-stability, and active control. The underlying idea is that, by harmonically exciting a multi-stable origami at its resonance frequencies, one can induce rapid folding between its different stable equilibria without the need for using responsive materials. To this end, we use a bi-stable water-bomb base as an archetypal example. Via numerical simulation based on a new dynamic model and experimental testing, we show that the inherent asymmetry of waterbomb bi-stability can enable dynamic folding with relatively low actuation requirements. For example, if the water-bomb initially settles at its "weak" stable state, one can use a base excitation to induce the intra-well resonance. As a result, the origami would fold and remain at the other "strong" stable state even if the excitation does not stop. The origami dynamics starting from the strong state, on the other hand, is more complicated. The water-bomb origami is prone to show inter-well oscillation rather than a uni-directional switch due to a nonlinear relationship between the dynamic folding behavior, asymmetric potential energy barrier, the difference in resonance frequencies, and excitation amplitude. Therefore, we develop an active feedback control strategy, which cuts off the base excitation input at the critical moment to achieve robust and uni-directional folding from the strong stable state to the weak one. The results of this study can apply to many different kinds of origami and create a new approach for rapid and reversible (self-)folding, thus advancing the application of origami in shape morphing systems, adaptive structures, and reconfigurable robotics.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源