床反力計測に基づく立位姿勢の推定

抄録

Standing balance evaluation of human enables us to predict the risk of falling due to aging and to clarify the effect of balance improvement training. The evaluation needs human posture and joint torques with external stimulus. In general, posture is measured by a motion capture system (MC) or inertia measurement units (IMU). To estimate the joint torques, it is necessary to add force plates to these sensing devices. However, MC and IMU are not practical from the view point of installation and precision. To solve the problem, this study tries to estimate posture on saggital plane and joint torques from only a force plate during standing on a shaking table. For the estimation, we regard human body as two-links (upper body and lower body) model and propose a method composed of three processes. In the first process, we regard the subject as a single link model and estimate its posture. In the second process, accelerations of upper body and lower body are estimated by using posture of the single link model. In the last process, posture of two links is calculated by integration of the accelerations estimated in the second process. This method utilizes Kalman filter in the calculation of all processes. The validity of the present method was verified by posture estimation in floor sway test.