A Pillbug-Inspired Morphing Mechanism Covered with Sliding Shells

TL;DR

This paper introduces a pillbug-inspired morphing mechanism with sliding shells, combining slider-crank and scissor mechanisms, enabling shape morphing and rolling motion for robotic applications.

Contribution

It presents a novel pillbug-inspired morphing structure with a combined mechanism and protective shells, including design, synthesis, and a functional robot prototype.

Findings

Successfully demonstrated shape morphing and rolling motion in a 3D model

Developed a robot with two modes: curling for hill descent and spreading for linear movement

Validated the mechanism's effectiveness through physical testing

Abstract

This research proposes a novel morphing structure with shells inspired by the movement of pillbugs. Instead of the pillbug body, a loopcoupled mechanism based on slider-crank mechanisms is utilized to achieve the rolling up and spreading motion. This mechanism precisely imitates three distinct curves that mimic the shape morphing of a pillbug. To decrease the degree-of-freedom (DOF) of the mechanism to one, scissor mechanisms are added. 3D curved shells are then attached to the tracer points of the morphing mechanism to safeguard it from attacks while allowing it to roll. Through type and dimensional synthesis, a complete system that includes shells and an underlying morphing mechanism is developed. A 3D model is created and tested to demonstrate the proposed system's shape-changing capability. Lastly, a robot with two modes is developed based on the proposed mechanism, which can curl up to roll down hills and can spread to move in a straight line via wheels.