MorphoBall: A Bio-Inspired Transformable Spherical Robot with Dual Terrestrial Gaits and Surface Swimming Capability
Jinyuan Liu, Guangzhi Tian, Yuqiang Jin, Ling Shi, Minglei Fu, Wen-An Zhang, Bo Chen
Abstract
MorphoBall is a bio-inspired, deformable spherical robot designed for multimodal locomotion across terrestrial and aquatic environments. By integrating a dual-mode drive system (spherical rolling and differential-drive) with a morphology-mediated propulsion mechanism, MorphoBall achieves adaptive mobility in diverse terrains, including flat ground, slopes, and water surfaces. A key innovation lies in the dual-function ciliary band, which provides both passive damping during terrestrial rolling and active propulsion during aquatic navigation. Model-based controllers are developed to regulate forward velocity, trajectory curvature, and roll tilt angle, demonstrating superior stability and responsiveness compared to baseline PID implementations. Experimental results validate MorphoBall's ability to autonomously navigate structured indoor environments and traverse unstructured outdoor terrains, achieving seamless mode transitions and completing missions 34% faster than single-morphology strategies. This work highlights the potential of morphology adaptation as a tool for enhancing environmental adaptability in mobile robotics.