Kinematic characterization of the Origami Spring with consideration to collision and deformation of components

Abstract

Origami Spring is one of the extendable Origamis which changes from a flat to a tower configuration. The important feature of the Origami Spring is that its whole structure simultaneously extends/contracts with a slight bending as a parasitic motion of the extension/contraction when only one of the segments is actuated. Therefore, such an observed macro motion of the Origami Spring can be regarded as a single DOF motion. Based on its folding diagram, the mobility of the Origami Spring was revealed to be three by the kinematic model obtained with regarding its folds as revolute joints. In order to figure out the discrepancy between the observation and mobility analysis, kinematic analysis of the Origami Spring has been carried out taking into consideration the collision and deformation of components. As the result of the analysis, it was clarified that the Origami Spring has actually three DOFs while one of the three DOFs generates a simple extension-contraction motion and the other two DOFs contribute to adjustments of its configuration to avoid collision of components within a small motion range. It was also presented that the observed behavior of the Origami Spring during extension and contraction can be explained by the internal energy based on deformation of components. Finally, the observed single DOF macro motion is reproduced with a model in which the deformation of the components is considered.