Musculoskeletal Simulation-Based Multi-Criteria Optimization Framework for Exoskeleton Design

Abstract

Robotic exoskeletons can enhance human locomotion by reducing its metabolic cost. Designing effective wearable assistive devices requires a systematic approach that accounts for the influence of device kinematics/dynamics and effects of assistance torques on human performance. While comprehensive human-subject experiments to evaluate multiple designs are often impractical, musculoskeletal simulations can serve as a powerful tool for optimizing exoskeleton designs and their corresponding assistance strategies. This paper presents a musculoskeletal simulation-based multi-criteria design optimization framework to systematically evaluate and compare various exoskeleton configurations under realistic physical constraints. In this study, the multi-criteria optimization framework is used to characterize the trade-off between metabolic efficiency and power use of mono- and bi-articular lower-limb exoskeleton configurations under optimal assistance torques. The multi-criteria optimization results provide a fair basis for rigorous comparison among various exoskeleton configurations and their corresponding optimal assistance torque profiles, considering realistic actuator saturation limits and the detrimental effects of exoskeleton reflected inertia on metabolic consumption. The results offer valuable insights to guide assistive exoskeleton designs under real-world constraints.