The Analysis Of Movement Mechanics And Modeling Of Human Lower Limb

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.