基于电液直驱的动力踝足假肢对行走步态的影响

An electro-hydrostatic powered ankle-foot prosthesis improves the locomotion gait of lower-limb amputees

针对传统被动式踝足假肢不具备主动出力功能,不能很好地满足下肢截肢患者需求的问题,本文提出了一种基于电液直驱系统的全主动液压驱动踝足假肢系统,并研究其对于下肢截肢患者行走步态的影响。该系统采用无刷直流伺服电机、双向齿轮泵、液压缸作为核心驱动部件,通过基于神经肌肉模型的前馈控制器实时拟合踝关节阻抗特性,实现踝关节的主动柔顺和主动出力功能。仿真结果表明:与传统被动假肢相比,该系统可以很好地拟合人体踝关节的动态特性,能够在行走过程中提供合适的缓冲和动力,能够有效地改善截肢患者的行走步态。

The traditional passive ankle prosthesis cannot meet the need of lower-limb amputees because it cannot provide an active force.Thus,this paper proposes a powered ankle prosthesis based on the direct-drive electro-hydraulic system and studies its effect on the walking gait of lower-limb amputees.A brushless DC servo motor,a bidirectional gear pump,and a hydraulic cylinder operate as kernel components and provide the initiative compliance and active force output of the ankle by fitting its impedance control in real-time using a neuromuscular model-based feedforward controller.The simulation results show that this system fits the dynamic characteristics of the human ankle to a greater extent in comparison with the traditional passive ankle prosthesis,offering lower-limb amputees the appropriate buffer and power when walking and effectively improving their walking gait.