共查询到20条相似文献,搜索用时 15 毫秒
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光纤水听器是在传统的水听器的基础上,从一个全新的光纤技术出发,实现传统的水声传感和声纳数据传输一体化,从而改善声纳系统的可靠性,并且降低其制造、使用和维护的总成本的新型水听器.文章简要介绍了光纤水听器的工作原理和结构,包括干涉型光纤水听器、强度型光纤水听器、光纤光栅水听器等三种.详细地对它们在国内外的发展以及应用方面进行了介绍. 相似文献
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Christopher M. Clark Christina Forney Esfandiar Manii Dylan Shinzaki Chris Gage Michael Farris Christopher G. Lowe Mark Moline 《野外机器人技术杂志》2013,30(3):309-322
This paper presents a prototype system that enables an autonomous underwater vehicle (AUV) to autonomously track and follow a shark that has been tagged with an acoustic transmitter. The AUV's onboard processor handles both real‐time estimation of the shark's two‐dimensional planar position, velocity, and orientation states, as well as a straightforward control scheme to drive the AUV toward the shark. The AUV is equipped with a stereo‐hydrophone and receiver system that detects acoustic signals transmitted by the acoustic tag. The particular hydrophone system used here provides a measurement of relative bearing angle to the tag, but it does not provide the sign (+ or ?) of the bearing angle. Estimation is accomplished using a particle filter that fuses bearing measurements over time to produce a state estimate of the tag location. The particle filter combined with a heuristic‐based controller allows the system to overcome the ambiguity in the sign of the bearing angle. The state estimator and control scheme were validated by tracking both a stationary tag and a moving tag with known positions. Offline analysis of these data showed that state estimation can be improved by optimizing diffusion parameters in the prediction step of the filter, and considering signal strength of the acoustic signals in the resampling stage of the filter. These experiments revealed that state estimate errors were on the order of those obtained by current long‐distance shark‐tracking methods, i.e., manually driven boat‐based tracking systems. Final experiments took place in SeaPlane Lagoon, Los Angeles, where a 1‐m leopard shark (Triakis semifasciata) was caught, tagged, and released before being autonomously tracked and followed by the proposed AUV system for several hours. © 2013 Wiley Periodicals, Inc. 相似文献
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基于矢量传感器的海洋声场观测潜标系统 总被引:1,自引:0,他引:1
以三维矢量传感器为核心,构建海洋矢量声场观测潜标系统。潜标由定深锚固定,工作于指定海深,可完成海洋矢量声场信息的观测与存储。矢量传感器输出的矢量声信号,经前置预处理后采样,并以文件分配表(FAT)32文件格式存储于潜标微型快擦写存储卡(CF)中;矢量传感器水下姿态由潜标中三维地磁姿态仪实时给出。潜标集成USB传输模块,回收后可通过USB串口完成数据上传PC机。海试结果表明:潜标系统可正确记录海洋矢量声场信息,且可稳定水下工作90d以上。 相似文献
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《Digital Signal Processing》2006,16(2):149-163
The class of alpha-stable distributions is better for modeling impulsive noise than Gaussian distribution in array signal processing. After briefly introducing the statistical characteristics of stable distribution and the fractional lower order statistics, including the covariation and the fractional order correlation, this paper proposes a new FOC-ESPRIT method of 2-D direction finding based on the fractional order correlation and subspace technique for underwater 2-D source localization using a vector hydrophones array under alpha-stable noise conditions. A vector hydrophone comprises two or three spatially co-located, orthogonally oriented identical velocity hydrophones (each of which measures one Cartesian component of the underwater acoustical particle velocity vector-field) plus an optional pressure hydrophone. Simulation experiments show that the proposed method is robust in a wide range of characteristic exponent values of stable distribution. Its performances are better than those of the conventional second-order statistics based ESPRIT algorithm, furthermore, the fractional order correlation is more suitable than the covariation in practical applications. 相似文献
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仿生矢量水听器水下监测记录装置 总被引:2,自引:1,他引:2
介绍了仿生矢量水听器水下监测记录装置的结构与功能,该装置使用FPGA控制ADS8365来采集两个仿生矢量水听器的声压与振速信号,并将采集到的数据用Flash进行存储,在实验完毕后将数据通过USB口读出,本系统也可以实现水声数据的实时监测与传输;为分别从方案设计、硬件实现及软件系统等方面进行了详细的研究和描述. 相似文献
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An optimal design problem for piezoelectric composite hydrophones is considered. The hydrophone consists of parallel piezoelectric rods embedded in a poroustransversely isotropic polymer matrix. We find the shape, volume fraction, and spatial arrangement of the piezoceramic rods, and the structure of the matrix material that maximizes the hydrophone performance characteristics. We found that the optimal composite consists of a hexagonal array of rods with small volume fraction, in a highly anisotropic matrix that is characterized by negative Poisson's ratios in certain directions. The performance characteristics of hydrophones with such a matrix are significantly higher than those with anisotropic polymer matrix. The results can be viewed as theoretical upper bounds on the hydrophone performance. 相似文献
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针对均匀传感器线阵应用被动合成孔径技术进行扩展阵列中存在阵元数较多利用率较低,且噪声累积误差问题,提出了一种基于最小冗余线阵的阵列扩展方法.该算法将四阶累积量方法和被动合成孔径技术相结合,能够采用较少的阵元获得较大的阵列有效孔径.先用四阶累积量方法对最小冗余阵作匀速直线运动采集的连续测量量作预处理,获得虚拟均匀线阵效果... 相似文献
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文章以现场可编程门阵列(FPGA)为控制核心,设计并实现了双音多频信号(DTMF)的产生与检测,DTMF信号的产生是在FPGA内部将两个不同频率的正弦波形合成一个双频数字信号,通过D/A转换器变为模拟信号输出。DTMF信号的检测以Goertzel算法为核心,计算出8个频点的幅值,通过比较大小判断出相应的电话号码。经过工程测试,该设计能够达到DTMF信号的产生与检测要求,结果表明,将DTMF编解码算法集成于FPGA系统中,使DTMF信号系统变得简单灵活,充分发挥了FPGA的优势。 相似文献
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声纳的应用极其广泛,海洋渔业以及军事应用使得声纳技术得到了大力发展;声纳湿端数据传输的可靠性、实时性是声纳系统性能得到保障的前提;设计一用于声纳湿端数据远传的DWDM光电交换模块;在该模块中,使用以太网交换芯片和两个DWDM光模块对数据进行多路转发并实现光通路的冗余备份,提升了系统可靠性的同时使网络拓扑更为灵活;由于DWDM光模块可将电信号转换为波长可选定的光信号,故通过若干该模块协同使用,可实现多路光信号复用即同时传输多条声纳水下阵缆的数据;经实际开发与测试,该模块以太网业务性能指标符合设计需求,且该模块已在某声纳工程项目中得到了应用,并可为其他领域数据远传工程应用提供设计参考。 相似文献
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为了避免矿井机车撞人事故的发生,提出了基于数字信号处理器结合现场可编程门阵列(DSP+FPGA)架构的轨道行人检测系统.通过A/D采样芯片对摄像机输出的模拟信号进行采样,将采集的数字信号由FPGA进行预处理;通过外部存储器接口(EMIF)将预处理后的信号传送至DSP,由DSP执行自适应阈值的边缘检测;基于极角、极径约束的霍夫(Hough)变换,降低维度的梯度方向直方图(HOG)特征提取,结合支持向量机(SVM)行人检测等算法;通过以太网接口,将检测的行人信息传送至上位机显示.实验结果表明:设计的轨道行人检测系统,检测效果良好,帧率可达8 fps,满足矿井环境对安全应用的要求. 相似文献
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为了提高光电式扭矩测量系统的灵敏度和系统的抗干扰的能力,设计了一种基于现场可编程门阵列(FPGA)和多路状态比较的扭矩测量系统,利用光电式多码道编码盘的旋转角测量功能进行扭矩测量.介绍了多码道码盘输出的多路信号的特征和状态细分的方法,并分析了扭矩测量的原理.硬件上采用FPGA来实现逻辑控制和数据的计数、锁存,简化了系统电路.并且把计数和状态信号传输到上位机进行处理显示,以便实时分析扭矩信号的振动.试验结果验证了该方案可应用于大型机械的动态扭矩测量系统. 相似文献
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