Design, fabrication and modeling analysis of a spiral support structure with superelastic Ni-Ti shape memory alloy for continuum robot

Abstract

In order to improve the working ability of continuum robots in confined space, a novel central support structure with the spiral cutting pattern is proposed in this paper. The spiral hollow scheme was selected through analysing different cutting patterns of the thin-walled superelastic Ni-Ti shape memory alloy (SMA) tube. Then the laser cutting process and heat treatment for fabricating the structure were analysed. The analysis results of their impact on the material characteristics proves that the laser cutting and heat treatment ensure the performance of the material. The single-segment and multi-segment prototypes both showed prospective motion ability in the flexural rigidity and continuous deformation tests respectively. Then the flexural rigidity model of the spiral structure was proposed, which was proved effective by comparing the model simulation and finite element analysis results. Furthermore, the central support structures with different flexural rigidities can be customized, which has broad application prospects in continuum robots.