Study on nonlinear crawling locomotion of modular differential drive soft robot

Abstract

This paper presents a novel modular differential drive soft robot (MDDSR) and its nonlinear model of crawling locomotion. The MDDSR consists of three differential drive soft modules (DDSMs) in series, and each module constructed by two bending soft actuators in parallel to be equally or differentially driven can achieve inchworm-like crawling movement with capability of straight and steering motion. Through sequential motions of the DDSMs, the MDDSR can perform straight and steering crawling locomotion. A nonlinear state-space kinematic model with the principle of minimum frictional work is built to characterize the MDDSR’s crawling locomotion, which is based on nonlinear bending behavior of the soft actuator and nonlinear crawling motion of the DDSMs. Feasibility of the proposed robot and its model is verified through locomotion experiments.