Development of a Mixed-Control Ankle Robot with Experimental Validation of Human Walking Performance

Abstract

Walking is not only essential for mobility but also contributes to quality of life and emotional well-being. However, for many older adults, age-related muscle fatigue makes walking physically demanding. To address this, we developed a wearable ankle-assist device designed to reduce walking burden and enhance comfort. The system supports multiple control strategies, including speed-based assistance and a combined speed-and-torque approach, each providing distinct levels of support across the gait cycle. To evaluate their effectiveness, six participants performed treadmill walking under four conditions: one without assist and three assistive modes. Among these, the mixed-control method, which integrates torque support with speed guidance, demonstrated the most significant improvement in walking distance and reduction in heart rate change. These findings suggest that targeted assistance at specific gait phases can effectively reduce physical strain and promote more comfortable and sustained walking.