A Model of Caterpillar Locomotion Based on Assur Tensegrity Structures

This paper presents an ongoing project aiming at building a robot composed of Assur tensegrity structures, which mimics caterpillar locomotion. Caterpillars are soft-bodied animals capable of making complex movements with astonishing fault-tolerance. In our model, each caterpillar segment is represented by a 2D tensegrity triad consisting of two bars connected by two cables and a strut. The cables represent the major longitudinal muscles of the caterpillar, while the strut represents hydrostatic pressure. The control scheme in this model is divided into localized low-level controllers and a high-level control unit. The unique engineering properties of Assur tensegrity structures, which were mathematically proved last year, together with the suggested control algorithm provide the model with robotic softness. Moreover, the degree of softness can be continuously changed during simulation, making this model suitable for simulation of soft-bodied caterpillars as well as other types of soft animals.