A design tool for a single vertex compliant-facet origami mechanism including torsional hinge lines

Principles from origami art are applied in the design of mechanisms and robotics increasingly frequent. A large part of the application driven research of these origamilike mechanisms focuses on devices where the creases (hinge lines) are actuated and the facets are constructed as stiffelements. In this paper, a design tool is proposed in which hinge lines with torsional stiffness and flexible facets are used to design passive, instead of active mechanisms. The design tool is an extension of a model of a single vertex compliant facet origami mechanism (SV-COFOM) and is used to approximate a desired moment curve by optimizing the design variables of the mechanism. Three example designs are presented: a constant moment joint (CMJ), a gravity compensating joint (GCJ) and a zero moment joint (ZMJ). The CMJ design has been evaluated experimentally, resulting in a root-mean-squared error (RMSE) of 6.4×10 -2 N.m on a constant moment value of 0.39N.m. This indicates that the design tool is suitable for a course estimation of the moment curve of the SV-COFOM in early stages of a design process.