首页|Adaptive Control of Lower-Limb Exoskeletons for Walking Assistance Based on Inter-Joint Coordination

Adaptive Control of Lower-Limb Exoskeletons for Walking Assistance Based on Inter-Joint Coordination

扫码查看
Unilateral motor impairment can disrupt the coordination between the joints,impeding the patient's normal gait.To assist such patients to walk normally and naturally,an adaptive control algorithm based on inter-joint coordination was proposed in this work for lower-limb exoskeletons.The control strategy can generate the reference trajectory of the affected leg in real time based on a motion coordination model between the joints,and adopt an adaptive controller with virtual windows to track the reference trajectory.Long Short-Term Memory(LSTM)network was also adopted to establish the coordina-tion model between the joints of both lower limbs,which was optimized by preprocessing angle information and adding gait phase information.In the adaptive controller,the virtual windows were symmetrically distributed around the reference trajectory,and its width was adjusted according to the gait phase of the auxiliary leg.In addition,the impedance parameters of the controller were updated online to match the motion capacity of the affected leg based on the spatiotemporal sym-metry factors between the bilateral gaits.The LSTM coordination model demonstrated good accuracy and generality in the gait database of seven individuals,with an average root mean square error of 3.5° and 4.1° for the hip and knee joint angle estimation,respectively.To further evaluate the control algorithm,four healthy subjects walked wearing the exoskeleton while additional weights were added around the ankle joint to simulate an asymmetric gait.From the experimental results,it was shown that the algorithm improved the gait symmetry of the subjects to a normal level while exhibiting great adapt-ability to different subjects.

Lower-limb exoskeletonAdaptive controlGait symmetryInter-joint coordinationMotion estimation

Chaoyang Li、Lincong Luo、Zhi Liu、Tianchi Chen、Songxiang Liu、Ye He、Xiaoan Chen、Lei Li、Wei Tech Ang

展开 >

School of Mechanical Engineering,Chongqing University,Chongqing 400044,China

Rehabilitation Research Institute of Singapore,Singapore 308232,Singapore

Department of Orthopedics,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology,Wuhan 430022,China

School of Mechanical and Aerospace Engineering,Nanyang Technological University,Singapore 639798,Singapore

展开 >

Graduate Scientific Research and Innovation Foundation of Chongqing,China国家留学基金委项目

CYB19062CSC202206050121

2024

仿生工程学报(英文版)
吉林大学

仿生工程学报(英文版)

CSTPCDEI
影响因子:0.837
ISSN:1672-6529
年,卷(期):2024.21(4)