基于声波传播时间估计的气流速度测量方法

 为实现对亚声速和超声速气流速度的统一测量,提出了一种基于声传感器的新型测量方法。首先,根据声波在亚声速和超声速气流中的传播特性,利用特定的测量装置建立了声波传播时间与气流速度之间的数学模型,从而将气流速度的测量问题转化为声波传播时间的测量问题。然后,在此基础上,利用计时法和最大似然估计(MLE)方法来估计声波传播时间;其中,计时法在实时性上优势明显,而MLE方法则在可靠性上优于前者。最后,分别从阵元位置扰动性、计时误差和克拉美-罗界(CRB)3个方面对所提算法的性能进行了分析与仿真验证。结果表明,该算法能够实现对亚声速和超声速气流速度的精确测量。

Airspeed measurement method based on propagation time estimation of acoustic waves

A novel airspeed measuring method based on acoustic sensors, applying to both subsonic and supersonic circumstances, is presented. Firstly,according to the propagation property of acoustic waves in subsonic and supersonic air current, the relationship between propagation time of acoustic waves and airflow velocity is derived for a given measuring equipment. Then, based on that, a timing method and a maximum likelihood estimation (MLE) algorithm are proposed to estimate the traveling time of acoustic waves. The timing method gains an advantage over the MLE algorithm in real-time, while the MLE algorithm is more reliable than the former. Finally, the performance of the proposed algorithms are verified by simulations and analyzed in terms of the perturbation of sensor position, the airspeed estimation error caused by timing error and the Cramér-Rao bound (CRB) on the estimation error of propagation time. The results show that the proposed algorithms are able to measure subsonic and supersonic airspeed with high accuracy.