摘要
为辅助手功能障碍患者在日常生活中更好地进行手部的康复训练与活动,提出一种基于柔性铰链的仿生外骨骼机械手。首先,基于弹性力学建立直梁型与半圆弧梁型柔性铰链刚度之间的映射关系模型,通过有限元模型改进半圆弧梁型柔性铰链的刚度设计式,并利用三铰链串联式外骨骼手指有限元模型验证单铰链刚度设计式的通用性和有效性;其次,基于修正后的刚度设计式,设计基于柔性铰链的仿生外骨骼机械手,通过绳索实现屈曲运动,通过柔性铰链的储能实现伸展运动,并根据齐次坐标变换建立相关的运动学模型,研究绳驱下的运动特性;最后,对试制的原型机进行屈曲性能与抓握能力的实验验证。外骨骼手指的仿真结果表明:单铰链的刚度设计式可用于复杂机构中各铰链的刚度计算,其误差值不大于3.5%;所试制的原型机手部执行构件仅重125 g,方便使用者日常携带。屈曲性能的实验结果表明:改进的刚度设计式减小了半圆弧梁型柔性铰链40%的刚度计算误差,使误差控制在5%以内,能快速获取满足弯曲条件的铰链几何尺寸。抓握能力的实验结果表明:两名健康受试者测量出外骨骼手单指能稳定输出8 N的指尖力,满足日常生活所需。因此,该外骨骼机械手可提供正常的关节活动度,其轻质便携及抓握能力高的特性还能辅助手功能障碍患者进行手部康复训练与日常活动。
In order to help patients with hand dysfunction perform hand rehabilitation training and activities better in daily life,this paper proposed a bionic hand exoskeleton based on flexible hinge. Firstly,based on elastic mechanics,the mapping relation model of stiffness between the straight beam and semi-circular beamtype flexible hinge was established. Then the stiffness design equation of semi-circular beam-type flexible hinge was improved by the finite element model and the universality and effectiveness of the equation were proved by the finite element model of three-hinge series finger exoskeleton. Secondly,based on the improved equation,this paper designed a bionic hand exoskeleton based on flexible hinge,which could realize buckling motion through ropes and stretch motion through flexure hinge. And the kinematics model was established by homogeneous coordinate transformation to study the motion characteristics of rope drive. Finally,experiments of bending performance and grasping ability were carried out on the prototype. The simulation results of finger exoskeleton showed that the stiffness design equation of single hinge could be used to calculate the stiffness of each hinge in the complex mechanism,and the error value was no more than 3. 5%. In this study,the weight of hand executive component of prototype was only 125 g,which was convenient for users to carry in daily life. The experimental results of bending performance showed that the improved stiffness design equation reduced the calculation error of 40% stiffness of semi-circular beam-type flexible hinge,and made the error within 5%,so that the geometric dimensions of the hinge satisfying the bending condition could be obtained quickly. The experimental results of grasping ability showed that two healthy subjects could measure the stable output of 8 N fingertip force from the single finger of the exoskeleton hand,which could meet the needs of daily life.Therefore,the hand exoskeleton could not only provide normal range of motion of the joints,but also
作者
孟巧玲
沈志家
陈忠哲
聂志洋
Meng Qiaoling;Shen Zhijia;Chen Zhongzhe;Nie Zhiyang(Institute of Rehabilitation Engineering and Technology,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Engineering Research Center of Assistive Devices,Shanghai 200093,China;Key Laboratory of Neural-functional Information and Rehabilitation Engineering of the Ministry of Civil Affairs,Shanghai 200093,China)
出处
《中国生物医学工程学报》
CAS
CSCD
北大核心
2020年第5期557-565,共9页
Chinese Journal of Biomedical Engineering
基金
国家自然科学基金(61803265)。
关键词
柔性外骨骼
柔性铰链
结构设计
刚度分析
仿生设计
flexible exoskeleton
flexible hinge
structure design
stiffness analysis
bionic design
