Design and Experiment of a Multi-driving Mode Bionic Hydraulic Knee Joint for Lower Limb Prosthesis

Abstract Achieving high drive efficiency remains a significant challenge in active knee prosthesis design. Inspired by human knee biomechanics, this study presents a novel biomimetic hydraulic drive system integrated with three human-like mechanisms: antagonistic muscle driving mechanism, dynamic simulation of muscle forces, and multi-stage collaborative energy supply. The system features a multi-stage hydraulic-rope hybrid transmission enabling adjustable damping and compliant motion control, coupled with a dual-cylinder configuration that boosts driving efficiency while delivering 29.7 Nm peak torque. A pump-valve hybrid control strategy is developed to dynamically adjust the flow and driving torque across gait phases, enhancing response speed and angular tracking accuracy. Through computational modeling, simulation, and prototype validation, we demonstrate that the proposed hydraulic drive system achieves efficient and responsive knee flexion and extension while meeting functional demands, reducing energy consumption by 20–50% compared to traditional pump-controlled systems. This study introduces a novel strategy for developing multimodal muscle-joint collaborative mechanisms, establishing a foundational framework for next-generation, high-performance bioinspired prostheses.