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6th International Conference on Mechatronics and Intelligent Robotics, ICMIR 2022

作者： Li, Xiaoyuan Hou, Hongying Wang, Kewen Meng, Chunxia Dalian Scientific Test and Control Technology Institute Binhai street 16 DaLian116013 China Science and Technology on Underwater Test and Control Laboratory Binhai street 16 DaLian116013 China

ISBN: (纸本)9781510656635

Target of underwater environments classification and distinguish using active sonar is very complex signal processing work, therefore, many research institutions in the world study the classification and recognition methods of underwater small targets using active *** recognition methods of static underwater small targets can be roughly divided into imaging method and echo method. The imaging method is based on high-frequency narrow beam to obtain the acoustic image of the target and its shadow while suppressing the reverberation interference, so as to realize the classification and recognition of the target. Imaging sonar has high working frequency, limited sonar range, and can not effectively identify false targets with similar geometry. Bright spot model and resonance scattering theory are important theoretical basis of target echo method. The two theories agree that the echo is the result of the interaction between the incident signal and the underwater target, which must contain the characteristics of the target, so it is feasible to detect the target by analyzing the characteristics of the echo signal. However, in the actual underwater target detection process, due to the weak target echo signal, complex seabed environment and target geometry, uncertain sound propagation conditions and so on, the target recognition based on echo method still has great challenges1,11,13-40 © 2022 SPIE.

关键词： Feature extraction

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Finite-Time Observer-Based Path-Following control of an Underactuated Surface Vehicle with Actuator Saturation and Fault

Finite-Time Observer-Based Path-Following Control of an Unde...

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2024 International Conference on Fuzzy Theory and Its Applications, iFUZZY 2024

作者： Zhang, Chengxiang Wang, Ning School of Marine Engineering Dalian Maritime University Dalian China State Key Laboratory of Maritime Technology and Safety China Dalian Key Laboratory of Green Power Control and Test for Intelligent Ships China

ISBN: (纸本)9798350352788

In this paper, a finite-time observer-based fault-tolerant control (F-FTC) scheme is proposed to address path following problem of an underactuated surface vehicle suffering from input saturation and actuator gain degradation. First, a finite-time observer is designed to accurately detect faults and complex system uncertainties within the faulty system. Second, a smooth dead-zone operator-based model is applied to avoid the potential non-differentiability in controller. Finally, the F-FTC is established by virtue of a first-order filtering system. Lyapunov theory is used to verify the closed-loop system stability while simulations experiments validate the merits of the proposed F-FTC scheme. © 2024 IEEE.

关键词： Dead zones

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Tuning interfacial charge transfer for efficient visible-light-driven photodegradation and simultaneous H_(2)evolution

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Journal of Materials Science & technology 2024年第1期168卷 35-49页

作者： Zhiyang Li Yaogang Chen Yinghe Zhang Wei Ai Qian Lei Tingjun Yao Dan Zhong Wenjie Liu Wenbiao Jin Lei Yang State Key Laboratory of Urban Water Resource and Environment Shenzhen Key Laboratory of Organic Pollution Prevention and ControlSchool of Civil and Environmental EngineeringHarbin Institute of Technology ShenzhenShenzhen 518055China Key Laboratory of Northwest Water Resources Environment and EcologyMinistry of EducationSchool of Environmental and Municipal EngineeringXi’an University of Architecture and TechnologyXi’an 710055China CNAS Accredited Test Center Guangdong Engineering Technology Research Center of Air PurificationHealthlead Co.Ltd.Shenzhen 518055China School of Science Harbin Institute of Technology ShenzhenShenzhen 518055China

The edge-graphitized carbon nitride(C_(3)N_(4)-C g)was prepared by secondary pyrolysis to construct ZnO/C_(3)N_(4)-C g(ZCN)type-Ⅱheterojunction photocatalyst via a facile sonication dispersion method,which achieved∼7.04-fold and∼18.3-fold enhanced visible-light-driven photocatalytic performance for refrac-tory micropollutant removal and simultaneous hydrogen(H_(2))evolution respectively compared to con-ventional ZnO/g-C_(3)N_(4)Step-scheme *** apparent quantum efficiency of the ZCN_(0.4)het-erojunction reaches 0.92%(λ=420 nm).Such excellent performance stems from that the edge-graphene moieties stitched onto the interface of heterojunction extend light absorption to the full visible spec-trum,meanwhile,the built-in electric field generated during Fermi level alignment accompanying fa-vorable band-bending structure provides an effective pathway for the rapid migration of photoinduced electrons via the edge graphene channel to improve interfacial charge separation ***,the midgap states introduced in ZCN heterojunction could temporarily retain photoexcited electrons to effectively inhibit the in situ carrier recombination for improved photocatalytic H_(2)***,ZCN/peroxymonosulfate system exhibited excellent anti-interference performance against complex water bodies under visible illumination due to the synergistic effect between the co-existing anions and organic ***,the eco-friendly nature of the ZCN/peroxymonosulfate system showed no biotoxicity of reaction filtrate on cell proliferation after treatment,which avoided secondary ***-ering the outstanding performance in photocatalysis,the ZCN system exhibits broad potential for practical applications in water pollution control and green energy production.

关键词： ZnO C_(3)N_(4)-C g Heterojunction Photodegradation Hydrogen evolution

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Modeling of Ship Target Radiated Noise Spectrum Characteristics

Modeling of Ship Target Radiated Noise Spectrum Characterist...

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Computer technology and Information Science (ISCTIS), International Symposium on

作者： Xuemeng Yang Science and Technology on Underwater Test and Control Laboratory Dalian China

This paper presents a comprehensive methodology for modeling ship target radiated noise spectrum characteristics, addressing the challenges of limited data availability. The proposed methodology includes data collection, preprocessing, feature extraction, and selection, along with the development of a noise spectrum model using advanced statistical techniques. Experimental evaluations using real-world ship noise data confirm the effectiveness of the proposed methodology in accurately capturing ship target radiated noise spectra. The findings have implications for underwater acoustic analysis and naval applications.

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Optimization of phase correction method based on multi frequency heterodyne principle

Optimization of phase correction method based on multi frequ...

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2023 International Conference on Optics and Machine Vision, ICOMV 2023

作者： WenZhe, Zou YaoQiong, Shen YuQing, Guan LiQin, Liu YunXia, Fu LiHua, Lei Shanghai Institute of Measurement and testing Technology Shanghai201203 China Shanghai Key Laboratory of Online Test and Control Technology Shanghai201203 China

ISBN: (纸本)9781510664777

A phase correction method based on multi frequency heterodyne principle is proposed for the phase jump error caused by multi frequency heterodyne phase solution. The traditional phase shifting method and multi frequency heterodyne are used to calculate the wrapping phase and the unwrapping phase. Aiming at the jump error in the unwrapping phase, the unwrapping phase is used to locate the error position. The wrapping phase is used as a reference to correct the position of the positioning error to obtain a new unwrapping phase. The experimental results show that under the optimization method, this method can effectively judge the jump, and obtain the unwrapping phase without jump error after eliminating the jump, which greatly improves the unwrapping accuracy and accuracy of the fringe pattern after phase unwrapping. © 2023 SPIE. All rights reserved.

关键词： Error correction

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Acoustic Signature Analysis and Numerical Simulation on Radiated Noise of underwater Contra-rotating Propellers

Acoustic Signature Analysis and Numerical Simulation on Radi...

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2021 OES China Ocean Acoustics, COA 2021

作者： Ma, Fu-Qiang Liu, Yan-Sen Xie, Li-Xun Hu, Wen-Shuai Science and Technology on Underwater Test and Control Laboratory Dalian China

ISBN: (纸本)9781728181905

The noise of contra-rotating propellers contributes a major part to the underwater vehicle. The special noise properties often become an important basis for detecting and identifying targets. This paper establishes the numerical simulation and calculation approach on the radiated noise properties of contra-rotating propellers, which was set up based on the theory of acoustic analogy and the large eddy simulation approach, and then the numerical simulation results are verified. Taking the DTMB contra-rotating propellers which consist of DTMB3689 and DTMB3849 as an example, the numerical calculation of the hydrodynamic performance of the contra-rotating propellers is carried out based on the solving method of Reynolds stress turbulence model and the results agree well with the experimental results. The disk velocity distribution, blade pressure distribution and hydrodynamic wake distribution of the contra-rotating propellers are analyzed. Analyzing the acoustic signature of contra-rotating propellers shows that the low frequency line spectrum not only reflects the multiplicative frequency feature, but also the additive frequency feature, and the relationship between the radiated noise of the contra-rotating propellers and its inherent structure and its motion state is correlated. © 2021 IEEE.

关键词： Hydrodynamics

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Multivariate Multiscale Sample Entropy for Multi-Channel underwater Acoustic Signal Analysis 7

Multivariate Multiscale Sample Entropy for Multi-Channel Und...

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7th IEEE Information technology, Networking, Electronic and Automation control Conference, ITNEC 2024

作者： Zhou, Jing Li, Yaan Wang, Mingzhou Shi, Lei School of Marine Science and Technology Northwestern Polytechnical University Xi'an China Xi'an Precision Machinery Research Institute National Key Laboratory of Underwater Information and Control Xi'an China

ISBN: (纸本)9798350370782

Multi-channel time series collected by arrays are prevalent in underwater acoustic signal processing and are crucial for uncovering the intrinsic characteristics of the observed system. This paper introduces the multivariate multiscale sample entropy (MMSE) to assess the complexity information in multi-channel underwater acoustic signals. Simulation analysis is employed to validate the effectiveness of the MMSE algorithm in extracting both within-channel and cross-channel information from multi-channel signals. Various types of simulated ship-radiated noise are generated to illustrate the MMSE algorithm's capability to differentiate between signals. Additionally, we employ MMSE to analyze various real-world signals, including ship-radiated noise, ambient noise, and interface reverberation. The MMSE results demonstrate its proficiency in differentiating various underwater acoustic signals compared to traditional frequency domain methods. © 2024 IEEE.

关键词： Frequency domain analysis

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Experimental Analysis of Statistical Property of Low Frequency Reverberation Envelope in Shallow Water

Experimental Analysis of Statistical Property of Low Frequen...

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2021 OES China Ocean Acoustics, COA 2021

作者： Cao, Feng Zhang, Xuegang Han, Jing Lv, Shuai Dalian Scientific Test and Control Technology Institute Science and Technology on Underwater Test and Control Laboratory Dalian China

ISBN: (纸本)9781728181905

Reverberation is the main background interference of active detection and identification, which is produced with active signal emission. It is traditionally assumed as a combination signal of a large amount of random scatters at the receiving hydrophone which leads to a Gaussian-distributed time-domain signal and a Rayleigh-distributed envelope following the central limit theorem. However, with the advent of high-resolution active sonar systems, the target-like scatter signals namely clutter arising from fluctuation or variety in seafloor or hydrographic would produce the non-Rayleigh reverberation with longer tail and it is a main factor restricting the active sonar long-range detection. Aiming at this phenomenon, the Rayleigh distribution model and two typical non-Rayleigh statistical models-the Weibull distribution and the K distribution model are studied using the low-frequency reverberation test data (signal center frequency at 420Hz) obtained from a typical shallow-water environment in the northern South China Sea. Based on the measured multi-sample reverberation data, the probability density distributions of different signal forms reverberation are calculated respectively. The parameters of different models are estimated by the method of moments (MOM) to perform the theory simulation and curve fitting, and then the correlation between data processing and model simulation results are calculated. Comparative analysis based on the experiments shows that the pulse length of transmitting signal has an important effect on the statistical characteristics of the reverberation in shallow water, which is reflected in the fact that the envelope distribution of short pulse-width reverberation presents stronger non-Rayleigh properties compared with long pulse-width reverberation. In addition, the long-range reverberation present stronger non-Rayleigh properties fitting with the non-Rayleigh models well relative to the short-range reverberation. The effect of frequency for

关键词： Reverberation

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Classification technology of underwater Targets in Decision Tree Based on Different Measurement Criteria

Classification Technology of Underwater Targets in Decision ...

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2021 IEEE International Conference on Signal Processing, Communications and Computing, ICSPCC 2021

作者： Sun, Yue Peng, Yuan Mu, Lin Zhang, Fengzhen Cao, Lin Science and Technology on Underwater Test and Control Laboratory Dalian China

ISBN: (纸本)9781665429184

In this paper, the selection of metrics for different branch attributes will affect the final division of different feature attributes. This article shares the principles of ID3 algorithm and CART algorithm using different information criteria, and use the princiciple of maximum information gain and the principle of minimum Gini index to generate decision trees. We use grid search and crass-validation methods to optimize CART algorithm, and finally we give the recognition accuracy of the feature data of the optimized algorithm. © 2021 IEEE.

关键词： Decision trees

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Research on jellyfish detection in cold source sea area of nuclear power plant based on high-resolution multibeam acoustic imaging

Research on jellyfish detection in cold source sea area of n...

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2021 International Conference on Computer Graphics, Artificial Intelligence, and Data Processing, ICCAID 2021

作者： Zhang, Jianfei Zhang, Xuegang Wu, Zhongpeng Science and Technology on Underwater Test and Control Laboratory NO. 14 Binhai Street Zhongshan District Liaoning Dalian116013 China

ISBN: (数字)9781510652170

ISBN: (纸本)9781510652163

The occurrence of cold source blockage in nuclear power plant not only affects the safety of power production, but also brings challenges to nuclear safety. Cold source reliability has become another important bottleneck restricting the development of nuclear power. Based on the consideration of improving the cold source safety of nuclear power plants, this paper studies the intrusion events of several typical marine organisms in nuclear power bases at home and abroad, analyzes the causes of the events, establishes a defense system in depth for marine organisms, identification, detection, early warning and hierarchical response, and uses underwater acoustic high-resolution multi beam detection method to detect marine organisms such as jellyfish and hairy shrimp, so as to obtain their echo characteristics, Analyze its distribution density in sensitive sea areas, and give effective early warning judgment. Among them, detection and early warning is the front-end disposal measure, which can provide emergency decision support for staff. Through the development and test of corresponding key equipment, the industrial safety risk is reduced, so as to improve the reliability of cold source. © 2022 SPIE.

关键词： Nuclear power plants

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