An Extensible Continuum Robot With Integrated Origami Parallel Modules

This paper presents a novel design for extensible continuum robots in light of origami inspired folding techniques. The design starts from a modularized crease pattern, which consists of two triangular bases and three waterbomb bases, and the folding process for creating an origami parallel structure from the crease pattern. The process further progresses to generate a compliant module with the origami parallel structure and a helical compression spring. A novel extensible continuum robot with integrated compliant parallel modules is then proposed to imitate not only the bending motion but also the contraction of continuum apparatus in nature. Mapping the origami parallel structure to an equivalent kinematic model, the motion characteristics of the origami structure are unraveled in terms of kinematic principles. The analysis reveals the mixed rotational and translational motion of the origami parallel module and the virtual axis for yaw and pitch motion in particular. According to the kinematics of the proposed continuum robot and features of the integrated helical spring in each module, three actuation schemes and resultant typical working phases with a tendon driven system are presented. A prototype of the extensible continuum robot with six modules connected in serial is produced as a proof of concept. The functionality of the proposed continuum robot with integrated origami parallel structure as its skeleton and helical springs as the compliant backbone is validated by the preliminary experimental results.