A Study on Estimation of Ground Contact, Gait Velocity and Position Using Wearable Sensor

This paper proposes the estimation method of gait velocity and position using wearable sensor system installing inertial sensor. This method decides the ground contact using the angular velocity and the posture information. The posture information is estimated from angular velocity and acceleration by the sensor fusion algorithm using the Extended Kalman filter. The gait velocity is calculated by using the angular velocity and the position vector from ground to the inertial sensor attaching on lower thigh in the ground contact states. We conducted the measurement experiment of 10m gait using the wearable sensor system. The gait velocity and position are estimated by using the measurement information. We can decide the ground contact by using the angular velocity and the posture information, and we estimated the gait velocity considering the ground contact and the rotational motion of lower thigh segment. Hence, we could obtain the gait velocity and position indicating the compensated values. Therefore, we indicated the effectiveness of proposed method. This method can be used to gait analysis using the wearable sensor system using inertial sensor.