《中国康复理论与实践》 ›› 2025, Vol. 31 ›› Issue (9): 1101-1115.doi: 10.3969/j.issn.1006-9771.2025.09.014

• 辅助技术 • 上一篇    下一篇

基于自适应时序对齐的智能下肢假肢运动意图识别

苏本跃1,2,3(), 刘文瑶2,3, 宗文杰2,3, 王保乾2,3, 盛敏4   

  1. 1 铜陵学院数学与计算机学院安徽铜陵市 244061
    2 安庆师范大学计算机与信息学院安徽安庆市 246133
    3 安徽省铜基材料数字化智能制造工程研究中心安徽铜陵市 244061
    4 安庆师范大学数理学院安徽安庆市 246133
  • 收稿日期:2025-07-30 修回日期:2025-08-28 出版日期:2025-09-25 发布日期:2025-10-10
  • 通讯作者: 苏本跃,E-mail:subenyue@sohu.com
  • 作者简介:苏本跃(1971-),男,汉族,安徽芜湖市人,博士,教授,硕士研究生导师,主要研究方向:康复医学、模式识别、人工智能。
  • 基金资助:
    1.安徽省高校优秀科研创新团队项目(2023AH010056);2.铜陵学院联合培养硕士研究生创新基金项目(24tlcb01)

Adaptive temporal alignment-based motion intention recognition for intelligent lower-limb prostheses

SU Benyue1,2,3(), LIU Wenyao2,3, ZONG Wenjie2,3, WANG Baoqian2,3, SHENG Min4   

  1. 1 College of Mathematics and Computer Science, Tongling University, Tongling, Anhui 244061, China
    2 College of Computer and Information, Anqing Normal University, Anqing, Anhui 246133, China
    3 Anhui Engineering Research Center of Intelligent Manufacturing of Copper-based Materials, Tongling, Anhui 244061, China
    4 College of Mathematics and Physics, Anqing Normal University, Anqing, Anhui 246133, China
  • Received:2025-07-30 Revised:2025-08-28 Published:2025-09-25 Online:2025-10-10
  • Contact: SU Benyue, E-mail: subenyue@sohu.com
  • Supported by:
    Excellent Innovative Research Team of Universities in Anhui Province(2023AH010056);Innovation Fund Project for Joint Postgraduate Training of Tongling University(24tlcb01)

摘要:

目的 针对智能下肢假肢运动意图识别中因个体步态差异和固定时间窗提取数据导致的运动误分类问题,提出一种基于自适应时序对齐的运动意图识别方法。

方法 在下肢运动中,对于连续两个步态周期数据,基于不同稳态模式下的类间差异性,通过跨周期帧间差分检测步态模式一致性。针对检测为单一稳态模式的样本,引入动态时间规整算法将相邻周期运动序列进行对齐,以减小个体差异。提取Haar小波4层分解低频系数构建特征向量,最后通过支持向量机实现分类。试验方案设计为:利用3个惯性测量单元采集测试对象在13种运动模式中下肢的加速度和角速度信息,测试对象为10例健康受试者和1例经胫骨截肢受试者,13种运动模式包括5种稳态模式(平地行走、上楼、下楼、上坡和下坡)和8种转换模式(平地行走与上楼、下楼、上坡、下坡的相互转换)。

结果 经过对10例健康人的模拟测试和1例截肢者的测试,5种稳态模式的识别准确率分别为99.24%和100%,13种运动模式的识别准确率分别为98.51%和89.11%。

结论 本研究提出了一种自适应时序对齐的运动意图识别方法,该方法有效减小个体步态差异对特征表征的干扰,增强了步态特征的一致性与判别性,最终实现了识别性能的提升。

关键词: 运动意图识别, 智能下肢假肢, 惯性测量单元, 动态时间规整, 自适应时序对齐, 帧间差分, 单一步态模式

Abstract:

Objective To address the issue of motion misclassification caused by individual gait differences and fixed time window data extraction in motion intention recognition for intelligent lower limb prostheses, this study proposes a motion intention recognition method based on adaptive temporal alignment.

Methods In lower limb motion analysis, for continuous gait cycle data, inter-class variability across different steady-state modes was utilized to detect gait pattern consistency through inter-cycle frame differencing. For samples identified as single steady-state modes, the dynamic time warping algorithm was introduced to align adjacent motion sequences, thereby reducing individual variability. Haar wavelet 4-level decomposition was applied to extract low-frequency coefficients for feature vector construction, and classification was performed using a support vector machine. The experimental protocol was designed as follows: three inertial measurement units were used to collect lower limb acceleration and angular velocity data from subjects performing thirteen locomotion modes. The test subjects included ten healthy participants and one transtibial amputee. The locomotion modes consisted of five steady-state modes (level walking, stair ascent, stair descent, ramp ascent, and ramp descent) and eight transition modes (mutual transitions between level walking and stair ascent/descent, as well as ramp ascent/descent).

Results Simulation tests on ten healthy individuals and one amputee showed recognition accuracies of 99.24% and 100% for five steady-state modes, and 98.51% and 89.11% for all thirteen motion modes, respectively.

Conclusion This study proposes an adaptive temporal alignment-based motion intention recognition method. The proposed approach effectively reduces the interference of individual gait variability on feature representation, enhances the consistency and discriminability of gait features, and ultimately improves recognition performance.

Key words: motion intention recognition, intelligent lower-limb prostheses, inertial measurement unit, dynamic time warping, adaptive temporal alignment, inter-frame difference, single gait mode

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