Robust control of electrohydraulic soft robots

• Published in: Frontiers in robotics and AI Vol. 11; p. 1333837
• Main Authors: Volchko, Angella, Mitchell, Shane K, Scripps, Tyler G, Turin, Zoe, Humbert, J Sean
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 02-08-2024
• Subjects: H infinity synthesis; HASEL actuators; linear system theory; robust control; soft robotics; uncertainty analysis; uncertainty analysis; H infinity synthesis; robust control; linear system theory; soft robotics; HASEL actuators
• ISSN: 2296-9144; 2296-9144
• DOI: 10.3389/frobt.2024.1333837

This article introduces a model-based robust control framework for electrohydraulic soft robots. The methods presented herein exploit linear system control theory as it applies to a nonlinear soft robotic system. We employ dynamic mode decomposition with control (DMDc) to create appropriate linear models from real-world measurements. We build on the theory by developing linear models in various operational regions of the system to result in a collection of linear plants used in uncertainty analysis. To complement the uncertainty analyses, we utilize
("H Infinity") synthesis techniques to determine an optimal controller to meet performance requirements for the nominal plant. Following this methodology, we demonstrate robust control over a multi-input multi-output (MIMO) hydraulically amplified self-healing electrostatic (HASEL)-actuated system. The simplifications in the proposed framework help address the inherent uncertainties and complexities of compliant robots, providing a flexible approach for real-time control of soft robotic systems in real-world applications.