Tetraspine: Robust terrain handling on a tensegrity robot using central pattern generators

Abstract

In order to produce a new mode of robust robotic locomotion and better understand how vertebrates coordinate motion with a compliant spine, we are developing a modular tensegrity robot inspired by the spine. The robot, called Tetraspine, is composed of rigid tetrahedron-shaped segments connected by six strings. Distributed impedance controllers coupled with central pattern generators (CPGs) generate tunable motion in the structure, making this the first mobile terrestrial tensegrity robot controlled by CPGs to the authors' knowledge. By eliminating rigid joints between segments and increasing compliance in the structure, Tetraspine is robust to perturbations; it traverses several types of irregular terrain successfully in simulation. Experiments in prototype hardware have proven the viability of the impedance controller and overall structure for locomotion.