【作者】 宋扬；

【导师】 莫世奇；

【作者基本信息】 哈尔滨工程大学 ， 工程硕士（专业学位）， 2019， 硕士

【摘要】 随着水下稳态辐射噪声测量技术和减振降噪技术的不断发展,各类水下航行器及水下武器的稳态辐射噪声已经显著降低,因此各个国家开始将研究方向逐渐向水下瞬态辐射噪声的测量技术集中。本文研究分析瞬态信号的测量量,其中主要研究瞬态信号的起始时刻和结束时刻以及瞬态信号能量的检测与计算方法。本文以空投入水及船转舵辐射噪声信号为研究对象,因此首先研究了空投入水信号及船转舵噪声信号的来源、产生过程及产生原因,并建立了空投入水辐射噪声和船转舵辐射噪声的模型。其次由于瞬态信号的起始时刻和结束时刻的获取需在检测器输出结果的基础上进行计算,因此研究了短时能量检测器,高阶量统计检测器,Power-Law检测器以及CFAR Power-Law检测器检测瞬态信号起始时刻和结束时刻的性能。分别对空投入水信号和船转舵信号模型进行检测,比较三种检测方法在不同信噪比下的检测结果,分析数据段长度,重叠度等参数对检测结果的影响,对比处理信号的特点,选择合适的参数进行检测。接着文章重点分析了瞬态信号的信噪比、能量、信号起始时刻与结束时刻,有效时长、最大峰值和平均峰值。其中,主要研究了在检测器的输出结果基础上,设计用来计算信号起始时刻和结束时刻的门限,从而对瞬态信号测量量提出指导性意见。此外,本文根据瞬态信号的特点,将平均声强器进行改进得到加权平均声强器直方图估计算法来对瞬态信号进行方位估计。分别使用门限计算所得的起始时刻和结束时刻与信号真实的起始时刻和结束时刻对信号进行截断,然后再进行方位估计,对比二者的方位估计效果。最后通过处理水池和松花湖的试验数据,进一步验证算法的可靠性。更多还原

【Abstract】 With the continuous development of underwater steady radiated noise measurement technology and vibration and noise reduction technology,the steady radiated noise of various underwater vehicles and underwater weapons has been significantly reduced.Therefore,various countries begin to focus their research direction on Underwater Transient radiated noise measurement technology.In this paper,the measurement index of transient signal is studied and analyzed.The detection and calculation methods of the initial and end time of transient signal and the energy of transient signal are mainly studied.In this paper,the radiated noise signals of air-input water and ship rudder are taken as the research objects.Firstly,the sources,generation process and causes of air-input water and ship rudder noise signals are studied,and the radiated noise models of air-input water and ship rudder are established.Secondly,because the acquisition of the start and end time of the transient signal needs to be calculated on the basis of the output of the detector,the performance of the short-time energy detector,the high-order statistical detector,the Power-Law detector and the CFAR Power-Law detector in detecting the start and end time of the transient signal is studied.The air input water signal and rudder steering signal model are detected separately.The results of three detection methods under different signal-to-noise ratios are compared.The effects of data length and overlap on the detection results are analyzed.The characteristics of signal processing are compared and the appropriate parameters are selected for detection.Then the paper focuses on the analysis of signal-to-noise ratio,energy,signal start and end time,effective time,maximum peak and average peak of transient signal.Based on the output of the detector,the threshold for calculating the start and end time of the signal is designed to provide guidance for the measurement of transient signals.In addition,according to the characteristics of transient signals,the weighted average intensity histogram estimation algorithm is improved to estimate the azimuth of transient signals.The signal is truncated by the start and end time of threshold calculation and the real start and end time of signal respectively,and then the azimuth estimation is carried out.Comparing the azimuth estimation results of the two methods.Finally,the reliability of the algorithm is further verified by processing the experimental data of the pond and Songhua Lake.更多还原