Core Viewpoint - The article discusses the development and advantages of a new type of ankle rehabilitation robot that utilizes redundant drive mechanisms to enhance rehabilitation outcomes and address limitations of existing devices [1][2]. Group 1: Ankle Rehabilitation Robot Overview - The ankle joint is crucial for weight-bearing but is prone to injuries, making rehabilitation essential for recovery [1]. - Traditional rehabilitation methods are lengthy and inconsistent, leading to the exploration of robotic assistance for more effective and continuous treatment [1]. - Current ankle rehabilitation robots are categorized into platform-type and wearable-type, with platform-type robots being the primary choice for functional rehabilitation due to their ability to perform complex movements [1]. Group 2: Challenges in Existing Designs - Existing designs of ankle rehabilitation robots often have complex structures that are difficult to manufacture and assemble, impacting their effectiveness [1][2]. - Many traditional robots do not adequately consider the stretching movements necessary for rehabilitation, which can limit their effectiveness [1][2]. Group 3: New Robot Design and Features - The new ankle rehabilitation mechanism (PARM-N) and its redundant drive form (PARM-R) are designed to accurately simulate three core movements required for rehabilitation: dorsiflexion/plantarflexion, inversion/eversion, and axial traction [2]. - The design simplifies the structure while enhancing performance, reducing manufacturing costs and assembly complexity [3][5]. Group 4: Performance Analysis - The kinematic analysis of the mechanism is crucial for performance evaluation and optimization, with the study employing methods like the Newton-Raphson method for solving position equations [6][10]. - The redundant drive mechanism avoids singular configurations that can hinder rehabilitation effectiveness, while the non-redundant configuration has multiple singular forms [10][19]. Group 5: Stiffness and Optimization - Stiffness performance is analyzed using virtual spring methods, with results showing that the redundant drive mechanism exhibits better stiffness characteristics in specific ranges compared to the non-redundant design [22][29]. - A multi-objective size optimization approach is applied to enhance the overall performance of the mechanism, resulting in significant improvements in both motion/force transmission and stiffness metrics [28][29]. Group 6: Research Publication - The findings of this research have been published in the journal "Mechanism and Machine Theory," highlighting the contributions of the team from Nanjing University of Aeronautics and Astronautics [18].