From CAD to URDF: Co-Design of a Jet-Powered Humanoid Robot Including CAD Geometry

TL;DR

This paper presents a co-design framework that integrates CAD geometry, control optimization, and structural safety analysis using FEM to improve the mechanical design and control performance of a jet-powered humanoid robot.

Contribution

It introduces a novel co-design approach combining multi-objective evolutionary algorithms and FEM analysis for robot design optimization.

Findings

Optimized robot links significantly improve control performance.

FEM filtering ensures structural safety margins are met.

Framework successfully applied to enhance iRonCub robot design.

Abstract

Co-design optimization strategies usually rely on simplified robot models extracted from CAD. While these models are useful for optimizing geometrical and inertial parameters for robot control, they might overlook important details essential for prototyping the optimized mechanical design. For instance, they may not account for mechanical stresses exerted on the optimized geometries and the complexity of assembly-level design. In this paper, we introduce a co-design framework aimed at improving both the control performance and mechanical design of our robot. Specifically, we identify the robot links that significantly influence control performance. The geometric characteristics of these links are parameterized and optimized using a multi-objective evolutionary algorithm to achieve optimal control performance. Additionally, an automated Finite Element Method (FEM) analysis is integrated into the framework to filter solutions not satisfying the required structural safety margin. We validate the framework by applying it to enhance the mechanical design for flight performance of the jet-powered humanoid robot iRonCub.