From Structural Design to Dynamics Modeling: Control-Oriented Development of a 3-RRR Parallel Ankle Rehabilitation Robot

TL;DR

This paper details the design and dynamic modeling of a wearable 3-RRR parallel mechanism for ankle rehabilitation, emphasizing a comprehensive development pipeline from structural design to simulation, with future control enhancements planned.

Contribution

It introduces a control-oriented development process for a novel 3-RRR parallel ankle robot, integrating structural design, kinematic and dynamic modeling, and preliminary simulation validation.

Findings

Stable joint coordination verified in simulations

Smooth motion tracking under rehabilitation trajectories

Foundation laid for personalized ankle rehabilitation systems

Abstract

This paper presents the development of a wearable ankle rehabilitation robot based on a 3-RRR spherical parallel mechanism (SPM) to support multi-DOF recovery through pitch, roll, and yaw motions. The system features a compact, ergonomic structure designed for comfort, safety, and compatibility with ankle biomechanics. A complete design-to-dynamics pipeline has been implemented, including structural design, kinematic modeling for motion planning, and Lagrangian-based dynamic modeling for torque estimation and simulation analysis. Preliminary simulations verify stable joint coordination and smooth motion tracking under representative rehabilitation trajectories. The control framework is currently being developed to enhance responsiveness across the workspace. Future work will focus on integrating personalized modeling and adaptive strategies to address kinematic singularities through model based control. This work establishes a foundational platform for intelligent, personalized ankle rehabilitation, enabling both static training and potential extension to gait-phase-timed assistance.