Development Of Electro Mechanical Motion Capture System Based On Ergonomics

With the rapid development of science and technology,the research of human motion characteristics is becoming more and more important.The research of human motion capture,as a kind of research subject with strong overlapping,is closely related to the development of science and technology.Nowadays,the principle of motion capture technology has been developed from the original Rotoscope to the motion capture scheme based on optical and acoustic principles.Above all,the motion capture scheme based on mechanical and electrical principle has obvious advantages in cost,precision and real time compared with other technical schemes,which has great research value.The key of electromechanical motion capture system is the design of its mechanical structure and the corresponding motion analysis method.Based on the analysis of the structure of the joints of the human body,this paper analyzes and summarizes the movement characteristics of the human joints,and establishes the corresponding multi rigid body kinematics model.On this basis,the overall structure of the motion capture system is designed,and the coordinate calculation method of each reference point is given according to the D-H method.The method of calculating the human motion posture based on MATLAB and the method of programming are established.Finally,the experimental prototype is made to verify the feasibility of the proposed scheme.The main contents are as follows:(1)This paper introduces the background and significance of motion capture technology and analyzes the reference of the research on the exoskeleton robot.The development status of motion capture system at home and abroad is also discussed in this paper.(2)Based on the study of the structure and motion principle of the joints,the motion characteristics,freedom degree and range of the joints are analyzed.Particularly,a simplified model of spinal motion is presented by analyzing the function of the spine and the macro characteristics of the human motion.(3)Based on the analysis of human joint motion,the whole structure of motion capture system is designed,including the main considerations in design flexibility to the path of human joint motion when the introduction of redundant degrees of freedom.At the same time,based on the complexity of the structure and the macroscopic characteristics of human motion,the degree of freedom is rearranged.Based on the mechanical structure,the installation scheme of the sensor is given.The calculation method of each datum point is given according to the D-H method.Based on the analysis of the distribution characteristics of the reference points in the space coordinates,a mathematical model is established to describe the human posture,and presents a method of motion calculation and program implementation based on MATLAB.(4)According to the design of the mechanical structure and motion capture scheme,an experimental prototype of the motion capture system was made.The selection and error analysis of angle sensor and data acquisition card are introduced.Through the human motion capture experiment,the rationality and feasibility of the motion capture scheme are verified.