Method for ultrasonic time-of-flight estimation based on extended Kalman filter

A method for ultrasonic time-of-flight estimation based on Extended Kalman Filter (EKF) is proposed. A theoretical model of two mixed echoes is developed based on the experimental model of one echo. The parameters of the theoretical model are estimated based on the EKF to give exactly the time-of-flight of ultrasonic. Because the phase diversity and time delay between the two echoes can affect the shape of echo envelop obviously, simulation experiments are performed for all the conditions of phase diversity and time delay. Simulation results show that the proposed method is of high precision and great ability of noise reduction.