摘要
为了研究人体行走时适应负载横向动态干扰的机制,从而设计可靠的穿戴式机器人辅助策略,提出采用基于双自由度受迫振动模型构建人-负载耦合系统。基于机械振动原理分析人-负载耦合系统特性,给出不同行走频率对人和负载位移的影响,提出人体通过调节行走频率适应负载横移扰动影响的假设;搭建负载横向动态干扰人体行走实验平台,获得实验对象无负重行走以及负载横向扰动下的肌肉协同特征及腿部激励频率,并与仿真结果进行对比分析。实验结果表明:负载横移扰动下人体行走是一个适应性调整并最后进入动态稳定的过程。其中,在负重情况下的人体上肢躯干摆动幅度比无负重情况下摆动增幅大60%,人体通过调整行走频率以及相关肌群肌肉协同策略来减少负载横向动态干扰带来的上肢躯干摆动影响。在负重情况下,不同行走速度的步态频率均趋向于人-负载耦合系统的固有频率,设定常速频率与固有频率相同,慢速下行走到达稳态时腿部激励频率上升4.30%,快速下腿部激励频率下降2.71%,负重下的行走控制策略与无负重下的行走控制策略相比发生了改变,以适应负载横移扰动带来的影响。
To investigate the mechanism of humans’adapting to the load fore-aft dynamic interference during walking and design a reliable wearable assistive robot strategy,a human-load coupling system is modeled as a two-degree-of freedom forced vibration system in this study.Firstly,based on the principles of mechanical vibration,the characteristics of the human-load coupling system is analyzed to examine the influence of different walking frequencies on human and load displacement.A hypothesis is proposed that humans adapt to the influence of load fore-aft disturbance by adjusting their walking frequency.Then,an experimental platform of load fore-aft dynamic disturbance is built to examine the muscle synergy characteristics and leg excitation frequencies of subjects walking without any added load and under load fore-aft disturbance.Compared with simulation results,the experimental results show that human walking under load fore-aft disturbance is a process of adaptive adjustment that eventually reaches dynamic stability.Specifically,under loaded conditions,the amplitude of upper limb and trunk swing is amplified by more than 60%compared to unloaded conditions.The influence of load fore-aft dynamic disturbance on upper limb and trunk swing is reduced by adjusting the walking frequency and muscle synergies.Under loaded conditions,the walking frequencies at different walking speeds tend to converge towards the natural frequency of the human-load coupling system.When the walking frequency is set to be equal to the natural frequency,the leg excitation frequency increases by 4.30%during slow walking and decreases by 2.71%during fast walking when reaching a steady state.The walking control strategy is changed compared to unloaded conditions to adapt to the influence of load fore-aft disturbance.
作者
刘艺格
刘凯
唐必伟
罗晶
庞牧野
LIU Yige;LIU Kai;TANG Biwei;LUO Jing;PANG Muye(School of Automation,Wuhan University of Technology,Wuhan 430070,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2024年第3期162-171,共10页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(62203341)。
关键词
负载横移
适应性调整
人-负载耦合
负重行走
load traverse
adaptive adjustment
human-weight-bearing coupling
walking with weights
