Using Multi-Stable Origami Mechanism for Peristaltic Gait Generation: A Case Study

This study proposes and examines a novel approach to generate peristaltic locomotion gait in a segmented origami robot. Specifically, we demonstrate how to harness elastic multi-stability embedded in a soft origami skeleton to create an earthworm-like locomotion. Origami is attractive for building soft robots because it can exhibit the essential compliance and reduce the part count. Most importantly, it can work as an actuation mechanism. Moreover, embedding multi-stability into an origami skeleton allows it to remain in any of the stable states and switch between different states via a series of jumps. In this paper, we use two serially connected bistable Kresling segments, each featuring a generalized crease pattern design and a foldable anchoring mechanism, to develop a driving module for crawling soft robot. Multi-stability analysis of this dual-segment module reveals a four-phase actuation cycle, which is then used to generate the peristaltic gait. Instead of controlling the segment deformations individually like in earthworm and other crawling robots; we only control the total length of our driving module. This approach can significantly reduce the total number of actuators needed for locomotion and simplify the control requirements. The purpose of this paper is to combine the best features of multi-stable mechanisms and origami to advance the state of art of earthworm inspired crawling soft robot. Our results demonstrate the potential of using multi-stable origami mechanisms to generate locomotion gaits without the need of complex controllers.