Exploring Effective Approaches to the Modelling of Lattice-based Structures for Soft Robots

Abstract

Accurate simulation of complex lattice structures is essential for advancing their application in soft robotics, where deformation control and adaptability are critical. This study recurs to Finite Element Analysis (FEA) to compare three simulation methodologies for a pneumatic elastic lattice actuator: Method 0, which uses the detailed geometry of the lattice-based structure of the actuator, Method 1, a traditional homogenized model, and Method H, an approach incorporating hyperelastic material behavior. Method 0 captures detailed geometry but suffers from computational inefficiency and high error rates, with discrepancies exceeding 20% in some regimes. Method 1 simplifies the geometry, significantly improving simulation speed by 35 times and reducing errors with peaks around 15%, though it remains limited in broader pressure domains. Method H offers a balance between speed (up to 11 FPS) and accuracy, by better capturing nonlinear behaviors, achieving mean errors below 10% for all regimes. This study provides insights into selecting appropriate simulation methods for tessellated soft actuators, as well as passive lattice structures.