Fig. 2
From: Ambulatory assessment of walking balance after stroke using instrumented shoes
Sensor fusion. The upper part (kinematics) is an extended Kalman filter that fuses the signals from the accelerometer (y Acc ) and gyroscope (y Gyr ) and applies zero velocity, height and ultrasound range measurement updates (d US ). Outputs are 3D position (p), velocity (v) and orientation (R) estimates of the forefoot segments. For kinetic estimation, data from the 3D force/moment sensors (y F and y M ) are used to estimate 3D CoM. With y M ) are used to estimate 3D CoM. With subscript k the samples are indicated. The estimation frequency is 50 Hz and ultrasound range updates are applied at approximately 13 Hz