| Measuring motions of human being is of great importance, as it is widely used in clinical diagnosis, motion capture, ergonomics, bionics etc. In the present thesis, a motion measuring and analyzing system for human upper limb based on Polhemus electromagnetic tracking system has been developed.In the present thesis, the author briefly introduced human anatomical structure, and discussed common methods for tracking and measuring human motions as well as commonly used kinematics models for human motion tracking and detection. The author attempted to extract unit motions from typical activities of daily living (ADL) using a video-recording camera. After assessment and dissection of 40 selected ADL performed by 9 healthy adult volunteers, 16 unit motions were extracted. As a conclusion, ADL can be successfully completed if freedoms of each joint meet all requirements of these unit motions.The author further specifically discussed the principles and methodologies of the human motion tracking based on an electromagnetic system. Having identified the drawbacks in current models, the author presented an improved method to determine the actual orientations of elbow flexion-extension axis and wrist flexion-extension axis using the electromagnetic tracking system, redefined the seven degrees of freedom (DoF) of human upper limb, and eventually proposed an optimized model of human upper limb. The author also provided the mathematical method to calculate the above-mentioned orientations and seven DoF in motion with data collected by the electromagnetic sensors, and successfully programmed the algorithm with MATLAB.Finally, experiments were performed to measure the actual elbow flexion-extension, wrist flexion-extension, and changes in 7 DoF of human upper limb in 2 unit motions. The results show that the optimized human upper limb model and the methods of calculating the 7 DoF are reliable and convenient. |
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