基于串联弹性原理和增广上三角分解辨识算法的踝关节阻抗估计方法  

Estimation method of ankle joint impedance based on series elastic principle and AUDI algorithm

作　　者：徐刚[1] 向馗[1] 唐必伟 庞牧野[1] XU Gang;XIANG Kui;TANG Bi-wei;PANG Mu-ye(School ofAutomation,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学自动化学院,湖北武汉430070

出　　处：《工程设计学报》2020年第5期552-559,共8页Chinese Journal of Engineering Design

基　　金：国家自然科学基金资助项目(61603284,51575412)。

摘　　要：研究人体关节阻抗对仿生机器人阻抗控制策略研究有重要意义。针对前期设计的踝关节阻抗测量装置(impedance detection device for ankle joint,IDDAJ)机械结构复杂及机理法建模难度大,提出了一种基于串联弹性原理和增广上三角分解辨识(augmented upper-diagonal decomposition identification,AUDI)算法的踝关节阻抗估计方法。为降低对IDDAJ驱动单元的性能要求,基于串联弹性原理,将其输入扰动中的大直流分量和动态高频分量分离;为降低建模难度,采用不受模型阶次影响的AUDI算法直接辨识IDDAJ阻抗模型,以获得更加准确的装置阻抗模型参数。根据联合阻抗测量原理,在得到IDDAJ阻抗模型后,采用AUDI算法辨识小腿肌肉不同激活程度下踝关节阻抗模型的参数。结果表明,采用AUDI算法辨识得到的IDDAJ阻抗模型的可靠性高于采用机理法得到的;在小腿肌肉放松状态下踝关节阻抗模型的参数处于同一数量级,踝关节阻抗模型的阻尼分量B、刚度分量K与小腿肌肉激活程度成正相关,这与现有文献中的结果一致。研究结果可为IDDAJ的研制和其他关节阻抗测量方法的研究提供参考。The research of the human joint impedance is of great significance to studying the impedance control strategy of bionic robots.In view of the complex mechanical structure of the impedance detection device for ankle joint(IDDAJ)designed in the early stage and the difficulty of modeling by the mechanism method,an estimation method of ankle joint impedance based on the series elastic principle and the augmented upper-diagonal decomposition identification(AUDI)algorithm was proposed.In order to reduce the performance requirements for the drive unit of the IDDAJ,the large DC(directcurrent)component and dynamic high frequency component required in the input disturbance was separated based on the series elastic principle.In order to reduce the difficulty of modeling,the IDDAJ impedance model was directly identified by the AUDI algorithm which was not affected by the model order,so as to obtain more accurate impedance model parameters of the device.According to the principle of union impedance detection,after the impedance model of IDDAJ was obtained,the impedance model parameters of the ankle joint under different activation levels of calf muscles were identified by the AUDI algorithm.The results showed that the reliability of the impedance model of IDDAJ identified by the AUDI algorithm was higher than that obtained by the mechanism method;when the calf muscles were relaxed,the impedance model parameters of the ankle joint were in the same order of magnitude,and the damping component B and stiffness component K of the ankle joint impedance model were positively correlated with the activation level of the calf muscles,which was consistent with the results in the existing literature.The research results can provide reference for the development of IDDAJ and the research of other joint impedance detection methods.

关 键 词：辨识算法 踝关节阻抗 肌肉激活程度 

分 类 号：TP23[自动化与计算机技术—检测技术与自动化装置] TP249[自动化与计算机技术—控制科学与工程]