Analysis of novel flexure-based joint

Abstract

As robots and other actuated mechanisms get smaller, so must their moving parts. A novel flexure-based joint was developed for Squishbot1 by a team at MIT, which can be made small (sub-cm), or much larger. Here, pseudo-rigid-body modeling is used in conjunction with the geometry of the joint mechanism in order to create analytic models of the forces at play in the joint, so as to better enable their design and use. Two mechanisms are analyzed: one in which the flexure is pinned to the moving legs, and one in which it is fixed. Systems of equations are generated for fixed flexure and pinned flexure joints, which are provided for the reader to use in order to develop their own mechanisms, and optimize them to their own applications. The fixed flexure, no leg contact model is tested for a particular configuration, and less than 3% error is found between the experimental and model data. The advancement of small (sub-cm) actuated mechanisms will push forward the development of small robots, and expand the terrains and applications in which robots can work.