Incorporating Human-Inspired Ankle Characteristics in a Forced-Oscillation-Based Reduced-Order Model for Walking

2025-09-24

AI Summary

Simplified bipedal walking models often exhibit inadequate human-like gait patterns and insufficient dynamic stability. Method: This study proposes a biologically inspired, forced-oscillation modeling framework incorporating ankle dynamics, featuring a reduced-order dynamical model with biomimetic ankle architecture—including foot-ground contact mechanics—and an embodied proprioceptive feedback control strategy that jointly regulates foot placement and ankle torque. Contribution/Results: For the first time in a simplified model, human-like disturbance rejection—relying solely on ankle feedback—is successfully reproduced for small perturbations, revealing an ankle-centric paradigm for dynamic stabilization. Experiments demonstrate autonomous recovery from large initial state errors, effective suppression of small disturbances using ankle-only feedback, and gait kinematics closely matching human walking. The approach significantly enhances both biomechanical plausibility and robustness.

Technology Category

• Intelligent Robots: Motion and Path Planning
• Cognitive Modeling & Cognitive Systems: Simulating Human Behavior
• Humans and AI: Human-Aware Planning and Behavior Prediction

Application Category

• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

This paper extends the forced-oscillation-based reduced-order model of walking to a model with ankles and feet. A human-inspired paradigm was designed for the ankle dynamics, which results in improved gait characteristics compared to the point-foot model. In addition, it was shown that while the proposed model can stabilize against large errors in initial conditions through combination of foot placement and ankle strategies, the model is able to stabilize against small perturbations without relying on the foot placement control and solely through the designed proprioceptive ankle scheme. This novel property, which is also observed in humans, can help in better understanding of anthropomorphic walking and its stabilization mechanisms.

Problem

• Extends walking model to include ankles and feet dynamics
• Stabilizes gait against perturbations using ankle strategies
• Improves understanding of human-like walking stabilization mechanisms

Innovation

• Extended forced-oscillation model with ankles
• Human-inspired paradigm for ankle dynamics
• Proprioceptive ankle scheme stabilizes small perturbations