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2020 2nd International Conference on Civil, Architecture and Urban Engineering, ICCAUE 2020

作者： Han, Jing Zhang, Xuegang Wu, Zhongpeng Cao, Feng Science and Technology on Underwater Test and Control Laboratory Dalian116013 China

This work devoted to research the temperature and salinity distribution in ocean turbulence. The sound velocity when ocean turbulence presented was calculated by the function relation between temperature, salinity, depth and sound velocity. The sound transmission loss was calculated when the ocean turbulence was presented or not and compared them. The sound field fluctuation resulted by ocean turbulence was analyzed. It was very significant to comprehend the mechanism and variation rule of ocean turbulence. Thus it was further study the effect of ocean turbulence on acoustic propagation. As an example, there was thermocline in the ocean water. The sound transmission loss was calculated when presented ocean turbulence or not. It analyzed the effect of ocean turbulence on acoustic propagation. The sound field fluctuation caused by ocean turbulence could reach 8dB. © 2020 Institute of Physics Publishing. All rights reserved.

关键词： Acoustic fields

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Evolving LSTM Networks for Time-Series Classification in EdgeIoT

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Mathematical Problems in Engineering 2023年第1期2023卷

作者： Cui, Pei Li, San Jiang, Kaina Liu, Zhendong Sun, Xingkai Science and Technology on Underwater Test and Control Laboratory Dalian China Wuhan Maritime Communication Research Institute Wuhan China Dalian Institute of Measurement and Control Technology Dalian China Beijing Huahang Radio Measurement Institute Beijing China

We proposed a novel approach to evolve LSTM networks utilizing intelligent optimization algorithms and address time-series classification problems in EdgeIoT. Meanwhile, a new optimizer called cultural society and civilization (CSC) algorithm is proposed to reduce the probability of stagnated in the local optima and increase the convergence speed. The suggested method could relieve the problem that the traditional data mining and pattern extraction methods cannot guarantee high accuracy and are hard to deploy on terminal devices. The proposed CSC algorithm and CSC-optimized LSTM model is examined on benchmark problems and demonstrates remarkable superiority over traditional methods and can be applied to support EdgeIoT for learning and processing. © 2023 Pei Cui et al.

关键词： Data mining

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Discrimination Between Broadband underwater Target Echo and Reverberation Based on Signal Spectral Flatness Feature

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Chinese Journal of Electronics 2019年第3期28卷 542-550页

作者： CHEN Yunfei LI Sheng JIA Bing ZHANG Yang WANG Zhenshan LI Guijuan School of Naval Architecture Dalian University of Technology Science and Technology on Underwater Test and Control Laboratory

Reverberation is the major interference of active detection, discrimination between target echo and reverberation is difficult when the reverberation is very strong. For the distinguishing of underwater target echo with strong interference, the modulation feature of echo and reverberation spectrum are characterized by signal spectral flatness measure, and the relationship between signal spectral flatness and target physical properties are theoretically formed. A method of discrimination between broadband underwater target echo and reverberation that based on signal spectral flatness characteristics difference is proposed and studied. Sea experiment results of complex underwater target broadband acoustic scattering have shown that signal spectral flatness characteristics of underwater target broadband echo and reverberation have obvious differences. Target echo and reverberation can be well distinguished using the proposed method.

关键词： Echo Reverberation Signal spectral flatness Benchmark

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Reconstruction and Evaluation of Ship Radiated Noise Signal in Ocean Channel

Reconstruction and Evaluation of Ship Radiated Noise Signal ...

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International Conference on Data Science and Business Analytics (ICDSBA)

作者： Chun Xia Meng Chun Yan Xia Xiao Yuan Li Science and Technology on Underwater Test and Control Laboratory Dalian China Dalian Scientific Test and Control Technology Institute Dalian China

Ship radiated noise can generally be regarded as a random process that undergoes steady states, but the complexity of its generation mechanism makes its spectral characteristics different from white noise signals. Realistic simulation of the time domain signal of ship radiated noise can improve performance of acoustic equipment. In this paper, the analysis methods of the ship's radiation noise line spectrum and continuous spectrum characteristics are studied. The near-field radiation noise data of a certain type of ship under the same operating conditions is analyzed in the time-frequency domain, and the statistically significant radiation noise spectrum characteristics are obtained. The probability density function is used to generate random numbers that meet this statistical characteristic to describe the frequency spectrum of underwater radiating sound sources at various frequencies, and the Fourier synthesis method is used to reconstruct the time-domain pass characteristic of the ship's radiated noise signal under arbitrary sound velocity conditions in shallow water. Finally, the evaluation method of the radiated noise signal modeling results is studied, and the reconstructed signal is evaluated by the similarity calculation between the measured and simulated signal. The results show that the reconstructed time domain signal has higher fidelity.

关键词： Time-frequency analysis Frequency synthesizers Statistical analysis Sea measurements Steady-state Frequency measurement Noise measurement

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Optimal design of emission waveform for acoustic scattering test under multipath interference

Optimal design of emission waveform for acoustic scattering ...

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作者： Jianglin WU Yunfei CHEN Bing JIA Guijuan LI Yang ZHANG Jintao YONG Science and Technology on Underwater Test and Control Laboratory

In order to reduce the impact of multi-path interference in the underwater target sound scattering test, the design of different forms of waveform such as CW-LFM+,CWLFM-,CW-HFM+ and CW-HFM-are mainly studied in this paper, the bellhop model is used to simulate the shallow sea multi-path propagation environment, and the one-way attenuation and two-way impulse response of the shallow sea multi-path channel are calculated. Based on this, the scattered signal of the point target after the combined signal passes through the shallow sea two-way channel is calculated, and according to the time-domain waveform and time-frequency diagram of the scattered signal of the simulated point target, the validity of model selection and parameter setting is verified. The ambiguity graph and contour line of the analog signal and the measured signal are calculated, so the transmission waveform with better time-frequency resolution can be selected, which provides support for the detection of the sound scattering signal of complex targets under multipath interference.

关键词： Waveform design shallow sea multipath combined signal ambiguity

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Echo Highlight Model of underwater Target and Design of FPGA Signal Simulation Module

Echo Highlight Model of Underwater Target and Design of FPGA...

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作者： Hu Chen Zhang Fengzhen Zhang Zhaohui Peng Yuan Jiang Yi Science and Technology on Underwater Test and Control Laboratory

The rapid development of FPGA provides a new platform for target signal simulation. In this paper, we first analyze the mathematical model of underwater target echo highlights, and then design a set of signal generating module based on FPGA, which can simulate the target echo signal under specific target characteristics according to the preset highlight table and copy signal. With 5° as the unit, the angle of incidence is switched between 0°-180 ° by using the mechanical keys. The angle can be displayed in real time through the digital tube. The output signal can be directly connected to the transducer and power amplifier to achieve a specific sound source level. Finally, the signal acquisition test of the simulation module is carried out. 37 angles in the range of 0°-180° were collected and analyzed. The distribution of echo highlights was compared with the table of highlights after matched filter. The module's performance meets the expectation.

关键词： echo FPGA highlight model signal simulation

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Research on underwater acoustic target recognition based on LOFAR spectrum and deep learning method

Research on underwater acoustic target recognition based on ...

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Automation, control and Robotics Engineering (CACRE), International Conference on

作者： Peibing Wang Yuan Peng Science and Technology on Underwater Test and Control Laboratory

ISBN: (数字)9781728198880

ISBN: (纸本)9781728198897

underwater acoustic target recognition has long been an internationally recognized problem. This paper combines the method based on LOFAR spectrogram and the deep convolutional neural network of deep learning hot spot method for underwater target radiated noise recognition, making full use of the separability information of target noise in different dimensions, and using the time spectrum chart as the depth Learn to enter data. In this paper, the basic principle and specific application process of the method are analyzed in detail, and the measured data are simulated and classified, and the simulation diagram and test results are given. The results show that the recognition rate of underwater target recognition with this method is high.

关键词： underwater acoustic target recognition LOFAR spectrum deep convolutional neural network

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Study on the characteristics of dolphins click signal

Study on the characteristics of dolphins click signal

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作者： ZHANG Zhaohui PENG Yuan Science and Technology on Underwater Test and Control Laboratory

Dolphins have a strong ability of target identification in the ocean, how to use it has become a new field of *** is mainly divided into three categories in the research of dolphin communication signals namely whistle, click and emergency signals. Dolphin Click sound is mainly used for target detection and recognition. In this paper, the research group designed a pool experiment to obtain the click signal when dolphin identify rubber bar, reef, aluminum bar and steel ball, and analyzes the signal form, frequency, spectrum change rule and other information from the perspective of time domain and time-frequency domain. The number of sine waves in click signal is analyzed when dolphins identify four kind of targets. We summarize six kinds of spectrum forms to classify the acquired acoustic signals, the probability of each spectrum form is analyzed and counted when dolphins detect and identify different *** results show that the click signal emitted by dolphins in target recognition is mainly one waveform click signal. The main energy of the frequency is concentrated at 0-200 khz.

关键词： Dolphin Click Signal Processing

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Experimental Study on Forward Acoustic Scattering in Stratified Water Turbulence

Experimental Study on Forward Acoustic Scattering in Stratif...

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作者： Jintao Yong Yunfei Chen Zhenshan Wang Bing Jia Rui Wang Jianglin Wu Science and Technology on Underwater Test and Control Laboratory

In this thesis, the forward acoustic scattering characteristics of two kinds of turbulence are experimentally tested and studied through the stratified tank simulation experiment. The fluctuation of the amplitude of the turbulent forward acoustic scattering signal with space and time is analyzed. The turbulent forward acoustic scattering intensity at different detection points in space and the variation trend of the turbulent forward acoustic scattering intensity at the same detection point with time are obtained. The experimental results show that the amplitude fluctuation frequency of the forward acoustic scattering signal decreases with time. In the density thermocline, the changing trend of the amplitude and transmission time of the acoustic signal at the adjacent position in the horizontal direction with time is similar, and the magnitude value is equivalent. The changing trend and magnitude of the acoustic signal amplitude at the adjacent depth in the vertical direction are different. The turbulence intensity has a significant impact on the amplitude fluctuation of forward acoustic scattering signal.

关键词： Turbulence Forward acoustic scattering Experimental test

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Experimental study on echo acquisition based on the correlation of low reverberation 49

Experimental study on echo acquisition based on the correlat...

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49th International Congress and Exposition on Noise control Engineering, INTER-NOISE 2020

作者： Yang, Baoshan Ma, Zhongcheng Zhu, Lingguo Liu, Wenzhang Dalian Scientific Test and Control Technology Institute 16 Binhai street Zhongshan District Dalian Liaoning China Science and Technology on Underwater Test and Control Laboratory 16 Binhai street Zhongshan District Dalian Liaoning China Harbin Engineering University No.145 Nantong street Nangang District Harbin City Heilongjiang Province China

ISBN: (纸本)9788994021362

In order to solve the problem of strong reverberation interference in the test of low-frequency echo characteristics of targets, the reverberation suppression method based on the time-space correlation characteristics of low-frequency reverberation is studied, and the real-time matching and suppression method of reverberation based on the separation of target echo and background reverberation based on target motion is proposed. The results show that, based on the matching processing of background reverberation and target echo parameters, this method can significantly reduce the low-frequency reverberation background in the test water area, and the reverberation in the lake test environment can be reduced by more than 10 dB, and the suppression effect is related to the correlation coefficient and phase difference of reverberation. This method has reference value for practical engineering application. © Proceedings of 2020 International Congress on Noise control Engineering, INTER-NOISE 2020. All rights reserved.

关键词： Reverberation

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