基于扩展卡尔曼滤波的超声波渡越时间估计

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

提出了一种基于扩展卡尔曼滤波的、适用于双回波重叠情况的超声波渡越时间估计方法。利用现有的单回波包络的经验模型,推导出了对应于双重叠回波包络的理论模型,并利用扩展卡尔曼滤波对其进行参数估计,以达到精确估计渡越时间的目的。由于两个回波的时间差和相位差对回波包络形状影响较大,因此对不同时间差和相位差条件均进行了仿真实验。实验结果表明:本方法能够准确地估计两个回波的渡越时间,并具有较高的抑制噪声能力。

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.