This study evaluates the effectiveness of the posture estimation method using an inertial sensor in the standing position generating small translational acceleration. The estimation method is established the sensor fusion algorithm focused on the local coordinate system by using the Extended Kalman filter, and we estimated 3D posture in the relative coordinate system from acceleration and angular velocity. The measurement experiment was conducted to clarify the accuracy of the estimation method using the disturbance generator, the wearable motion sensors installing inertial sensor and the motion capture system. We compared the result for ankle joint angle estimated by previous method and proposed method and focused on translational acceleration. We indicated the effectiveness of proposed method in the motion measurement of standing with small translational acceleration.
