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6th IEEE International Symposium on Computational Intelligence in Robotics and Automation. A wearable inertial sensor system for human motion analysis. Tao Liu Robotics and Dynamics Lab Kochi University of Technology 2005-6-29. Introduction.
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6th IEEE International Symposium on Computational Intelligence in Robotics and Automation A wearable inertial sensor system for human motion analysis Tao Liu Robotics and Dynamics Lab Kochi University of Technology 2005-6-29
Introduction Some application fields of human motion analysis Functional electrical stimulation (FES) Human dynamic analysis Humanoid robot
Introduction Research Background • Some human motion analysis systems have been developed, but are complicated and expensive for product developments. • In this research, a six-D reaction force sensor had been finished, and the wearable motion analysis system is constructed for the dynamic analysis of human walking. • A more compact measurement system with intelligent computation methods will be the focused problem in this research.
Methods and Materials Hardware Description Gyro: ENC-03J Accelerometer: ADXL202 A/D converter card with 14 bit resolution
Two-axis Accelerometer ωy Ay Methods and Materials Hardware Description Base board of inertial sensors X: Gyro Ax 70mm Y: Gyro ωx 100mm
Methods and Materials Hardware Description Wearable motion measurement device with inertial sensors
Methods and Materials The Gait Phase Analysis Methods • Gait phases of a normal walking • Physical sense of each gait phase • Introduce the Fuzzy inference system into the detection of gait phases • Post-process of the FIS outputs (Pointer digital filter design) • The optical motion analysis system (In next step to validate above inference)
Methods and Materials The Gait Phase Analysis Methods • Gait phases of a normal walking Swing Toe-rotation Heel-rotation Stance
y ωy x ωx z Methods and Materials The Gait Phase Analysis Methods • Physical sense of each gait phases If ωx=0 AND ωy =0 AND Ax=0 AND Ay=0 Then ‘Stance Phase’; If ωy<0 AND Ax≠0 AND Ay≠0 Then ‘Swing Phase’; If ωy>0 AND Ax≠0 AND Ay≠0 Then If the case is before the ‘Swing Phase’ of the same walking cycle Then ‘Toe-rotation Phase’ Else ‘Heel-rotation Phase’. ωx: X-Rotational angular velocity ωy: Y-Rotational angular velocity Ax: X-Acceleration Ay: Y-Acceleration
Methods and Materials The Gait Phase Analysis Methods • Introduction of Fuzzy Inference System (FIS) Mamdani method is used in this FIS In this FIS, four inputs and one output were designed
Methods and Materials The Gait Phase Analysis Methods • Introduction of Fuzzy Inference System (FIS) Fuzzy Input De-fuzzy Output
Methods and Materials The Gait Phase Analysis Methods • Introduction of Fuzzy Inference System (FIS) Rules Designed for the FIS If ωx=0 AND ωy =0 AND Ax=0 AND Ay=0 Then ‘Stance Phase’; If ωy<0 AND Ax≠0 AND Ay≠0 Then ‘Swing Phase’; If ωy>0 AND Ax≠0 AND Ay≠0 Then If the case is before the ‘Swing Phase’ of the same walking cycle Then ‘Toe-rotation Phase’ Else ‘Heel-rotation Phase’.
Methods and Materials The Gait Phase Analysis Methods • Introduction of Fuzzy Inference System (FIS) The FIS is developed by using MATLAB Results View
Methods and Materials The Gait Phase Analysis Methods • Post-process of the FIS outputs (Pointer digital filter design) Output of FIS Last filter result
Methods and Materials The Gait Phase Analysis Methods Hi-Dcam • The optical motion analysis system Knee marker Ankle marker High speed camera by NAC Heel marker Toe marker
Experiment Study • Data sampling of two-axis Gyroscope and two-axis accelerometer • Gait phases analysis results in two walking tasks • Validating the analysis results using the optical motion analysis system
Experiment Study • Data sampling of two-axis Gyroscope and two-axis accelerometer
Experiment Study • Gait phases analysis results of an object
Experiment Study • Validating the analysis results using the optical motion analysis system
Experimental Results Analysis and Conclusion • The wearable inertial sensors system can be used for foot-motion analysis; • A fuzzy inference system was used on the detection of gait phase. • A digital point filter was design for the results data processing . • The results of gait phases analysis can be used for next step dynamic analysis when a reaction force measurement system is integrated into this analysis system.