【作者】 洪晓明；

【导师】 叶明； 孟明；

【作者基本信息】 杭州电子科技大学 ， 控制理论与控制工程， 2009， 硕士

【摘要】 研制下肢假肢是为了改善残疾人的生活质量和促进医疗福利事业的发展,同时智能假肢也是机器人学和生物医学工程领域深受关注的研究方向。智能下肢假肢通过检测穿戴者的运动状态来控制假肢运动,从而提高步态的灵活性、协调性和安全性。我国下肢残疾者人数众多,国内在智能下肢假肢的研究水平上也明显落后于欧美发达国家,因此为肢体残疾人提供性能优良、价格低廉的假肢器械是残疾人事业发展的重要任务。人体下肢运动分析和建模是研究假肢的重要内容,本文紧密围绕国家自然科学基金资助项目“膝上假肢的运动力学信息获取与多运动模式控制方法研究(60705010)”,主要做了以下几个方面的工作:建立人体下肢运动生物力学信息获取系统,利用表面电极获取下肢运动肌电信号;利用多轴加速度传感器来检测大腿和小腿的倾角,获取肢体的姿态以及膝关节角度和角速度;下肢的脚与地面之间接触状态和作用力等信息采用足底安装压力传感器的方式检测。根据人体的结构和运动学的分析,建立人体下肢运动数学模型。比较动力学建模中通常采用的拉格朗日法、牛顿-欧拉法等的优缺点,选用拉格朗日建模方法,从系统能量角度出发构建人体下肢的动力学模型,并进行动力学分析,得到关节力矩。基于Matlab/SimMechanics仿真工具箱人体下肢运动系统建模,选取了平地行走、上坡、上阶梯三种不同的运动模式,每种运动模式下分为摆动期和支撑期两个阶段,建立相应的模型,以各关节的角位移、角速度、角加速度为输入,仿真得到各种运动模式下髋关节和膝关节力矩。在平地行走模式下,将求解拉格朗日方程所得到的关节力矩与Matlab/SimMechanics建模仿真所得的力矩进行比较,两者基本吻合,证明了建立的模型比较合理。运用数学统计方法对下肢运动参数进行分析,首先应用新阈值消噪方法对肌电信号进行消噪处理,用平均值法提取特征向量,利用回归分析的方法研究表面肌电信号与关节力矩之间的关系,通过数据分析,表明关节力矩与表面肌电信号近似成线性关系,在此基础上得出了关节力矩与表面肌电信号的表达式。运用回归分析中多项式拟合方法对力矩与时间的关系进行建模,得出了各种运动模式下关节力矩与时间的关系,为下肢假肢的控制方法研究提供了实验与理论的依据。更多还原

【Abstract】 To improve the living quality and welfare benefits of amputees, researches have been made on lower limb prostheses, which is also an attentive research project in the fields of robotics and biomedical engineering. Intelligent lower limb prosthesis control the prosthetic movement by detecting the movement state of the wearer, thereby enhancing the flexibility of gait, coordination and security. As to the research progress, the level of domestic research has lagged behind developed countries in Europe and America, However, there are a good number of people with disabilities on lower limbs, Therefore, to provide high-performance and low-cost prosthetic devices for the disabled is the important task.The analysis and modeling of human lower limb is an important content of study of the prosthesis, The article closely around the National Natural Science Foundation-funded project (60705010) ,mainly doing the following areas:Human lower limb biomechanics information retrieval system is established, surface electrodes are used to obtain lower limb movement EMG; multi-axis acceleration sensor is used to detect the inclination of the thigh and calf, access to physical gestures as well as the knee angle and angular velocity; the plantar pressure sensor is used to detect Inter-contact state and force and other information between the foot and the ground.According to the human body structure and movement mechanics analysis, to make the mathematical model of human lower limb movement, As to the advantages and disadvantages of dynamic modeling method in the commonly used, including Lagrangian method, Newton-Euler law, Lagrangian modeling method is chosen, from the view of the system energy to build a dynamic model of human lower limb, and also dynamic analysis to gain the joint torques.Based on Matlab / SimMechanics simulation toolbox, to make the human lower limb motor system model, select flat walk, uphill and on the ladder three different sports modes, each sports mode is divided into swing phase and support phase two stages, the establishment of the corresponding model, angular, angular velocity, angular acceleration as input, a variety of hip, knee torque are gained as simulation of models. In the plains walking mode, the comparison of the torque derived from Lagrangian method solving equation and the torque derived from modeling and simulation Matlab /SimMechanics, they are similar, that establishment the reasonable of the model.The mathematical statistical methods are used for analysis of lower limb movement parameters, first EMG signal de-noised by the new threshold de-noising method, with the feature vector extracted by average method, the relationship between surface EMG and joint torque are analyzed, we found joint torque and surface EMG are approximate linear relationship, on this basis, expressing joint torque and surface relation. Using regression analysis polynomial fitting method to find the relationship between torque and time in a variety of exercise modes for the lower limb, all of these providing experimental and theoretical basis to the study of human lower limb control method.更多还原