Research Progress and Development Trend of Powered Transfemoral Prosthesis Control Technology

Powered transfemoral prostheses can significantly enhance the mobility and quality of life for lower-limb amputees by restoring natural walking functions in daily activities. This paper comprehensively reviews the current research status and development trends in control technologies for powered transfemoral prostheses, with particular focus on control methodologies, sensing systems, control frameworks, and application challenges. Firstly, the fundamental working principles and design objectives of powered transfemoral prostheses at home and abroad are introduced, and the main challenges of current control technologies are analyzed, such as improving gait symmetry, reducing energy consumption, and enhancing adaptability. Secondly, various sensors commonly employed in prostheses are explored, including six-axis force sensors, inertial measurement units (IMUs), and electromyography (EMG) sensors, and their roles in improving control accuracy and environmental adaptability are discussed. Subsequently, the hierarchical control framework is systematically summarized, including the estimation methods for user states and environmental information in high-level controllers, different mid-level control strategies based on impedance models versus reference trajectories, and recent advancements in human-in-the-loop optimization. The advantages and limitations of various mid-level control approaches in practical applications are critically discussed. Finally, future development directions in prosthesis control technology are prospected, particularly highlighting research prospects in personalized adjustment, intelligent control, and adaptability enhancement.