【作者】 吕云飞；

【导师】 孙大军；

【作者基本信息】 哈尔滨工程大学 ， 水声工程， 2010， 博士

【摘要】 矢量水听器是由无指向性的声压水听器和具有偶极子指向性的质点振速传感器复合而成,其矢量通道的指向性与频率无关,在低频和甚低频声场参数获取、远距离目标探测与定位中具有广阔的应用前景。矢量水听器同步、共点测量声场空间一点处的声压和质点振速的三个正交分量,相比较声压水听器,增加了信息量,为后续的信号处理提供了更广阔的选择空间。同时也对安装平台提出了新的要求,安装平台的选择和设计是确保矢量水听器应用的基本前提之一,尤其在低频和甚低频段。随着研究的深入,矢量水听器技术必将更广泛的应用在水声领域。本文在回顾了矢量水听器的低频校准技术、海洋浮标技术和被动目标方位跟踪技术的基础上,以甚低频矢量水听器潜标探测系统为背景,对低频和甚低频矢量水听器校准技术、低频和甚低频声场矢量观测系统和单矢量水听器目标方位跟踪技术进行了理论和试验研究。首先,论文针对低频和甚低频动圈式矢量水听器校准困难的问题,对水池中低频和甚低频矢量水听器校准技术进行了研究。借鉴空气声学相关原理,分析了矩形水池中低频声源辐射连续简谐波时的声场。在靠近声源的位置,声场中以直达声为主,并呈球面扩展规律。基于水池声场的这一特性,论文中提出了低频和甚低频矢量水听器的水池校准方法。水池中矢量水听器的校准是在球面波声场中进行的,为获得等效平面波声场中的结果,需要对测量的原始结果进行球面修正,文中给出了等效的校准方法。论文介绍了利用该校准方法在水池中对动圈式矢量水听器进行校准的工作,校准结果验证了该方法的可行性。其次,论文中进行了声场矢量观测系统的研究。针对矢量水听器工作时对安装平台姿态有一定要求的特点,设计了基于潜标的安装平台。潜标体的受力分析和海上试验结果都证明了潜标体在水下姿态平稳,满足矢量水听器工作要求。设计了低噪声数据采集单元,使观测系统能够正确的采集声场信息。设计了自容式存储单元和无线通讯网络,采集的数据可以自容式存储或实时上传至主站。多次海上试验表明,声场矢量观测系统中的潜标在水下姿态稳定,采集单元能够正确记录声场信息。该系统能够完低频和甚低频声场矢量信息的记录,是低频和甚低频声场矢量分析、远距离目标探测与定位技术研究的重要手段。再者,针对单矢量水听器的被动目标方位跟踪问题,在利用互谱声强法对目标方位进行预估计的基础上,提出了采用概率数据关联算法对在跟踪波门内的方位值进行关联,更准确的估计目标方位。目标的方位跟踪属于非线性跟踪范畴,方位角随时间的变化并非线性,论文引入了输入估计法来估计方位角的加速度值,改进了概率数据关联算法,对目标的方位角进行跟踪。针对多个目标存在时目标方位角轨迹可能存在交叉的情况,采用联合概率数据关联算法可以对目标进行分离跟踪。最优联合概率数据关联算法计算量大,论文中提出了一种新的近似解耦联合概率数据关联算法对目标方位角进行跟踪,减小了计算量。论文最后对全文进行了总结,并对下一步的工作进行了展望。更多还原

【Abstract】 Vector sensor is combined by sound pressure hydrophone and particle velocity sensor with dipole directivity, the directivity of vector channel is independent of frequency. Vector sensor has broad application prospects in acoustic field parameters acquisition and long range target detection at low and very low frequency. Compared with sound pressure hydrophone, vector sensor can synchronously measure sound pressure and three orthogonal components of particle velocity at the same location in acoustic field. It can provide more information and more choice for signal processing. The design of installation platform is one of the basic premise for vector sensor application, especially in low and very low frequency band. With a detailed study, vector sensor technology will be more widely used in underwater acoustic domain.In the thesis, vector sensor calibration technology, sea buoy technology and inactive target bearing tracking technology are reviewed. Based on subsurface buoy detection system with very low frequency vector sensor, the theoretical and experimental research is presented about vector sensor calibration technology in low and very low frequency band, vector acquisition system of acoustic field in low and very low frequency band and target bearing tracking algorithm with single vector sensor.Firstly, for the problem that moving-coil vector sensor calibration in low and very low frequency band is difficult, the vector sensor calibration method in tank is studied in low and very low frequency band. The relevant principles of air-acoustic are used for reference and acoustic field in rectangular tank is analyzed when low frequency sound source produces continuous harmonic wave. The direct sound of sound field is dominant near sound source and propagates by spherical expansion. Based on the character of sound field in tank, vector sensor calibration method in low and very low frequency band in tank is presented. When vector sensor is calibrated in spherical wave sound field in tank, for equivalent result of plane wave sound field, the raw measurement is spherically corrected and correction method is provided for calibration. In the thesis, the process of moving-coil vector sensor calibration in tank is introduced, results reveal that the calibration method is feasible.Secondly, vector acquisition system of acoustic field is studied in the thesis. For the character that there are some demands of vector sensor to installation platform, the installation platform is designed. The posture of subsurface buoy in sea water is proved stably by stress analysis of subsurface buoy and the results of sea trial and the installation platform is suitable for vector sensor. Low-noise data acquisition unit is designed for correct information acquisition of sound field. The self-contained storage unit and wireless communication net are designed and acquisition data can be self-stored in subsurface buoy or transmitted to main station in real time. Several sea trials show that the posture of vector acquisition system of acoustic field is stable and the system can correctly record information of acoustic field. The system can record vector information of acoustic field and is an important means of acoustic field vector analysis and long range detection in low and very low frequency band.Thirdly, for the problem of inactive target bearing tracking by single vector sensor, base on pre-estimation of target bearing by cross-spectral sound intensity method, the algorithm that the target bearings in validation gate are associated by probabilistic data association is presented and the estimation is more accurate. Target bearing tracking is non-linear problem and azimuth angle change with time is non-linear, so input estimation algorithm is used to enhance the performance of probabilistic data association for target bearing tracking. When there is bearing cross by multi-targets, joint probabilistic data association algorithm is used to track recognition. The computation quantity of optimal joint probabilistic data association algorithm is large, for reducing computation quantity, a new approximate decoupling joint probabilistic data association algorithm is presented and computation quantity is reduced.A summary of full thesis and the future prospects of research are in the final.更多还原