Abstract
Powered ankle prostheses effectively assist people with lower limb amputation to perform daily activities. High performance prostheses with adjustable compliance and capability to predict and implement amputee's intent are crucial for them to be comparable to or better than a real limb. However, current designs fail to provide simple yet effective compliance of the joint with full potential of modification, and lack accurate gait prediction method in real time. This paper proposes an innovative design of powered ankle prosthesis with serial elastic actuator (SEA), and puts forward a MLP based gait recognition method that can accurately and continuously predict more gait parameters for motion sensing and control. The prosthesis mimics biological joint with similar weight, torque, and power which can assist walking of up to 4 m/s. A new design of planar torsional spring is proposed for the SEA, which has better stiffness, endurance, and potential of modification than current designs. The gait recognition system simultaneously generates locomotive speed, gait phase, ankle angle and angular velocity only utilizing signals of single IMU, holding advantage in continuity, adaptability for speed range, accuracy, and capability of multi-functions.
Abstract (translated)
动力脚踝假肢有效地协助人们完成腿部缺失的人的日常活动。具有可调节 compliance 和能够预测和实现缺失腿意图的性能出色的假肢是至关重要的,以便它们能够与真实的腿部相媲美或更好。然而,目前的设计未能提供具有完整潜力的关节 compliance 的简单而有效的 compliance,也没有实时准确的步态预测方法。本文提出了一种创新性的设计,即使用 serial elastic actuator (SEA) 动力脚踝假肢,并提出了基于 MLP 的步态识别方法,能够准确和连续地预测更多的步态参数,用于运动感知和控制。假肢模拟生物关节,具有相似的重量、扭矩和功率,可以协助步行速度达到 4 米/秒。为 SEA 提出了一种新的平面 torsional spring 设计,其 stiffness、耐久性和修改潜力都比目前的设计更好。步态识别系统同时生成运动速度、步态阶段、脚踝角度和角速度,仅利用单个惯性测量单元(IMU)的信号,具有连续、适应速度范围、准确性和多功能能力的优势。
URL
https://arxiv.org/abs/2309.08323
