水下无人系统学报

Review on the Development of Diver Detection Sonar System

HUANG Ying-song, GE Hui-liang, WANG Fu-yin, XIE Yong

2020, 28(1): 001-9. doi: 10.11993/j.issn.2096-3920.2020.01.001

[Abstract](971) [PDF 2737KB](861)

Abstract:
Diver attack has become one of the serious threats against harbors and near-shore waters. Underwater diver detection is an important new research direction in the field of non-traditional security. Corresponding research is of great significance for the security and defense of key waters such as harbors, large vessels, coastal entertainment sites and offshore oil rigs. This paper first discusses the main characteristics of the diver, points out the difficult problems in diver detection, and elaborates the relevant principles of the diver detection sonar(DDS). Then, it takes the representative products made in Britain, Israel, Canada, China and other countries as examples to introduce the current development status of DDS systems in detail. Finally, it summarizes the research results of the DDS in China, points out the gap of DDS technology between China and foreign countries, and forecasts the development trend of the DDS technology.

Key Technologies of Underwater Acoustic Glider: A Review

SUN Qin-dong, LAN Shi-quan, WANG Chao, WANG Wen-long

2020, 28(1): 010-17. doi: 10.11993/j.issn.2096-3920.2020.01.002

[Abstract](2239) [PDF 2142KB](185)

Abstract:
Underwater acoustic glider has the characteristics of long voyage, long endurance, high invisibility and low cost. It is an advantageous platform for the underwater moving target detection and fine measurement of marine hydrological environment. This paper review the research progress of underwater acoustic gliders in the world, and briefly describes their system compositions and functions. The key technologies of underwater acoustic glider design and scale application are discussed, including vibration and noise reduction, autonomous control, attitude control, multi-mode hybrid propulsion, acoustic sensor design and application, target attribute autonomous discrimination, safe deployment, and recycling. This paper may provide reference for the development of similar unmanned undersea detection equipment in China.

CFAR Detection of Range-Extended Target in Pareto II Reverberation

LUO Hai-li, XU Da, CHEN Mo-jiang, HAO Cheng-peng

2020, 28(1): 018-23. doi: 10.11993/j.issn.2096-3920.2020.01.003

[Abstract](360) [PDF 452KB](230)

Abstract:
With the improvement of modern sonar range resolution, the number of effective scatters in each space pro-cessing unit is greatly reduced, the reverberation distribution model is no longer subject to the central limit theorem, and the target echo occupies a continuous number of distance units. If the Gaussian reverberation model and the model of point target are still used in this case, the detection performance of the high-resolution sonar system would be greatly reduced. This paper discusses the detection method for the range-extended target in Pareto II reverberation based on geometric mean-constant false alarm rate(GM-CFAR), and analyzes the detection performances of the binary integrator, the fuzzy algebraic product integrator, and the fuzzy algebraic sum integrator through the Monte-Carlo method. Simulation results show that the three integrators can effectively detect range-extended targets in Pareto II reverberation, and the detection performances of these two fuzzy logic integrators are better than that of the binary integrator. In addition, the fuzzy algebraic sum integrator works better under multiple jamming targets background than the other two integrators. This research may provide a reference for improving the detection performance of high resolution sonar.

Nonlinear PD Controller Design for Autonomous Undersea Vehicle-Manipulator System

LI Xiao-gang, WANG Hong-du, LI Ming

2020, 28(1): 024-32. doi: 10.11993/j.issn.2096-3920.2020.01.004

[Abstract](440) [PDF 573KB](253)

Abstract:
For dealing with the nonlinearity, strong coupling and complexity of the working environment of autonomous undersea vehicle-manipulator system(AUVMS), a linear extended state observer(LESO)-based control scheme is designed, in which an AUV with two-link manipulator is divided into 5 subsystems. In each subsystem, external disturbances(such as ocean current, surge and vortex) and internal uncertainties(imprecise modeling, coupling effect and measurement error) are lumped as total disturbances, and LESO and linear feedback control law are designed for estimation and compensation, respectively. The convergence of LESO and the dynamics of estimation error are analyzed. Considering that the power and torque generated by the power device of undersea vehicle are limited, the upper limit of the control input should be set according to the physical characteristics of the power device in practical circumstance, however few literatures have studied the saturation control of undersea vehicle with manipulator system. Therefore, a nonlinear proportional-derivative(PD) controller with input saturation limit is designed and its stability is analyzed. The nonlinearity, high coupling and complex disturbance of the AUVMS are dealt with by using the “total disturbance” concept of the LESO, and the input saturation controller is adopted to ensure the industrial applicability of the control scheme. In addition, the effectiveness of the proposed control algorithm is verified by simulation and comparison with traditional proportional-integral-derivative(PID) control and slide mode control.

Numerical Analysis on Active Acoustic Homing Performance of Anti-Submarine Torpedo under the Action of Noise Jammer

ZHANG Fang-fang, LI Wen-zhe, DONG Xiao-ming, SONG Jia-ping

2020, 28(1): 033-38. doi: 10.11993/j.issn.2096-3920.2020.01.005

[Abstract](466) [PDF 434KB](194)

Abstract:
To reveal the effect of high-frequency noise jammer on active acoustic homing performance of anti-submarine torpedo, models of active acoustic homing and high-frequency noise jammer are established considering acoustic per-formance of submarine. The effect of the jammer at different relative azimuths and initial distances, as well as the homing performance of anti-submarine torpedo under high-speed steering evasion, is numerically analyzed by using the separate variable method. Results show that: 1) the interference effect of the high-frequency jammer is enhanced with the decrease of the absolute value of its relative azimuth and the initial distance, and the homing distance of the anti-submarine torpedo is hence reduced; 2) submarine adopting high-speed reverse-direction maneuvering evasion after release jammer will further reduce the homing distance of the torpedo, but will not change the interference sector of the jammer. This research may provide a basic model and data support for operational effectiveness analysis of anti-submarine torpedo.

A Target Tracking Algorithm for UUV Based on Huber M-CKF

WANG Bin, WEN Quan, FAN Shi-dong

2020, 28(1): 039-45. doi: 10.11993/j.issn.2096-3920.2020.01.006

[Abstract](869) [PDF 578KB](223)

Abstract:
To improve the target tracking accuracy for unmanned undersea vehicle(UUV), a robust M maximum likelihood estimation cost function is introduced into Huber-cubature Kalman filter(H-CKF) for UUV’s target tracking, and the CKF matrix is linearized by changing the normalized innovation covariance. UUV motion model and observation model are established to compare the Huber M-cubature Kalman filter(HM-CKF) with the converted measurement Kalman filter, the cubature Kalman filter and the extended Kalman filter(EKF) under different non-Gaussian noise interferences, and the results show higher filtering precision and stability of the HM-CKF than the traditonal algorithm in complicated undersea acoustic environment.

An Estimation Algorithm of Maneuvering Target Movement Elements

CHENG Shuai, ZHANG Qin-nan, WANG Li-wen

2020, 28(1): 046-50. doi: 10.11993/j.issn.2096-3920.2020.01.007

[Abstract](441) [PDF 388KB](145)

Abstract:
For estimation of maneuvering target movement elements, the Kalman filter method based on the uniform acceleration model has more applications, however, due to the defect of Kalman filter itself, this method is only applicable to the target with uniform acceleration in the straight line movement situation, but is impossible to estimate the motion elements of the target in turning. In order to overcome this problem, an estimation algorithm of maneuvering target movement elements is proposed in this paper. Through periodic reset of the covariance matrix of Kalman filtering, the algorithm can make the absolute value of the gain matrix always keep larger, make the correction effect of estimation at a satisfactory level, and ultimately solve the estimation problem of maneuvering target movement elements including turning movement. Mathematical simulation results show that the proposed estimation algorithm has strong tracking ability for maneuvering target, and meets the requirement of estimation error. It is simple and easy to be realized in engineering.

Research on Acoustic Scattering of Underwater Complicated Target Based on Sound-Solid Coupling

ZHOU Ye, WEN Wei, HAN Jian-hui, YANG Ri-jie

2020, 28(1): 051-56. doi: 10.11993/j.issn.2096-3920.2020.01.008

[Abstract](530) [PDF 1042KB](860)

Abstract:
In view of the low simulation fidelity of the existing simple model for actual underwater target, the scattered acoustic field of the two-dimensional simple model of submarine after excitation is simulated numerically by using the COMSOL sound-solid coupling algorithm and the perfectly matched layer(PML). The result is compared with that of the same model calculated by using the finite element analysis software ANSYS, and both results are basically consistent, verifying the effectiveness of the COMSOL sound-solid coupling algorithm in calculating the scattered acoustic field of large target. Furthermore, the interior cabin structure and its structural material attributes are established for a submarine structure, which improves the fidelity of the model to the actual target, and the sound field of re-radiation after excitation is simulated. The simulation results may be taken as a reference for the numerical analysis of active sonar signals and the development of underwater active detection equipment.

Flux-Weakening Control of PMSM Based on Three-Degree-of-Freedom Dynamic Internal Model Decoupling

YOU Qian-liang, WEI Hai-feng, CHANG Xu, TIAN Hui-feng

2020, 28(1): 057-66. doi: 10.11993/j.issn.2096-3920.2020.01.009

[Abstract](354) [PDF 1935KB](187)

Abstract:
Aiming at the problem that the dynamic performance of permanent magnet synchronous motor(PMSM) of undersea vehicle propulsion system in flux-weakening operation is unsatisfactory, the influence of direct-quadrature axis current regulator on the dynamic performance of PMSM is studied based on the PMSM flux-weakening theory, and a flux-weakening control strategy of PMSM based on three-degree-of-freedom dynamic internal model decoupling is proposed. Considering the fact that traditional internal model decoupling cannot take the decoupling effect, response speed and steady-state error into account at the same time, current regulation factors are introduced to modify the decoupling controller. On this basis, to the problem that the direction of quadrature axis current regulation is opposite to the expected direction of the system when the output torque leaps, the information of quadrature axis current is added into the current regulation factors and the fuzzy controller is used to optimize the current regulation factors in real time. Simulation and experimental results show that the proposed strategy can synthetically solve the problems of unsatisfactory performance of quadrature axis current regulator and serious current coupling in flux-weakening operation, improve the dynamic performance of PMSM, and has the triple functions of anti-saturation, current decoupling and flux-weakening control.

Two-Dimensional Numerical Simulation of Underwater High-Speed Gas Jet and Complex Wave System

HOU Zi-wei, HUANG Xiao-long, LI Ning, WENG Chun-sheng

2020, 28(1): 067-74. doi: 10.11993/j.issn.2096-3920.2020.01.010

[Abstract](387) [PDF 878KB](153)

Abstract:
Aiming at the generation and development of underwater high-speed gas jet, based on the Euler two-fluid model and the space-time conservation element and solution element(CE/SE) method, a model of jet with high speed and high pressure in free water is established, and the gas-liquid two-phase numerical simulation of the external flow field of underwater nozzle is carried out to analyze the flow field characteristics of initial jet, as well as the complex wave systems and shapes in the process of underwater high-speed gas jet injection. And the phenomenon of “hitting back” inside the jet is preliminarily discussed. The results show that the flow field presents slow axial development and rapid radial expansion due to the blocking effect of water after the underwater gas jet injection at high speed. A complex wave system in which the leading shock wave, the reflected shock wave and the intercept shock wave cross each other is formed in the high pressure zone of the gas front. The interaction of complex wave systems makes the jet develop downstream continuously with an axial concave shape, and irregular shape of the main jet interface appears. The gas retrospecting phenomenon occurs in the process of jet propagation, which leads to the “diamond” shape in the jet. The complex change of the flow field pressure at nozzle outlet caused by propagation of wave systems and their interaction has an important effect on the propulsion performance of underwater engines.

Modeling and Simulation Analysis of Torpedo’s Water-Entry Impact Based on CEL Algorithm

WANG Sheng, GUO Jun, ZHAO Qi, BIAN Min-hua, TIAN Shu-hong

2020, 28(1): 075-80. doi: 10.11993/j.issn.2096-3920.2020.01.011

[Abstract](511) [PDF 2900KB](146)

Abstract:
To improve the accuracy of the strength simulation of overall torpedo in the torpedo’s water-entry impact calculation, the coupled Eulerian-Lagrangian(CEL) algorithm is used, and the calculation model is modified via experiment. The linear reinforced elastic-plastic constitutive model of the material is introduced into the model in order to improve the accuracy of calculation results. The connection characteristics of the connecting structure of torpedo cabin shells are considered to guarantee simulation accuracy. Conclusions are drawn that the connection characteristics should be fully considered in treatment of the connecting structure and the connecting structure should be rationally simplified, and the two wedge-ring bands of the wedge-ring structure have the functions of buffering and vibration reduction. This study may be helpful for the designs of water-entry schemes of rocket-assisted torpedo and air-dropped torpedo, and may provide a reference for the analyses of torpedo water-entry impact and wedge-ring connecting structure.

Multi-Medium ALE Algorithm-Based Simulation of Vertical and High-Speed Water Entry of Cylinder

WANG Zhen, WU Mao-lin, SUN Yu-song, PENG Jing-hui

2020, 28(1): 081-88. doi: 10.11993/j.issn.2096-3920.2020.01.012

[Abstract](467) [PDF 1661KB](226)

Abstract:
Aiming at the problem of high-speed water entry load of large-caliber flat-head revolving body launched by offshore platform in the future, the validity of the multi-medium arbitrary Lagrange-Euler(ALE) algorithm for calculating such problems is verified via water entry load and cavity in order to investigate the dynamic response of the round chamfer of cylinder head to the vertical water entry of the cylinder, so as to make the shape design of flat-headed cylinder with the round chamfer meet the requirement for high-speed water entry strength. The vertical water entry process of the cylinders with different chamfers at a velocity of 300 m/s is numerically simulated, and the dynamic responses under the impact of water entry are obtained. By analyzing the velocity and acceleration of the cylinder in water entry, conclusions are drawn as follows: 1) In the initial stage of water entry, with the increase of the cylinder head chamfer, the attenuation of velocity becomes smaller; 2) The impact acceleration of the cylinder oscillates as it enters water; 3) The round chamfer of a certain size can effectively reduce the impact acceleration of the cylinder when it enters the water, and the peak value of impact acceleration of spherical-headed cylinder entering water is less than one tenth of that of flat-headed cylinder; and 4) The peak load of a flat-headed cylinder in vertical water entry process is linearly and positively correlated with the area of its head dome. This study may provide reference for the research on the impact process of cylindrical structure and the design of high-speed body.

A Sonar Image Recognition Method Based on Convolutional Neural Network Trained through Transfer Learning

ZHU Zhao-tong, FU Xue-zhi, HU You-feng

2020, 28(1): 089-96. doi: 10.11993/j.issn.2096-3920.2020.01.013

[Abstract](866) [PDF 1084KB](344)

Abstract:
A sonar image recognition method using convolutional neural network trained by transfer learning is proposed aiming at the data shortage problem in making use of conventional training method for sonar image recognition. Based on the principle of transfer learning, the existing pre-trained network is fine-tuned and retrained to reduce the demand for training data. Pool experiment of the scale model verifies the effectiveness of this method. Experimental results show that, on the basis of AlexNet pre-trained network, the transfer learning method uses less training data compared with the conventional learning method, and achieves a recognition rate of 95.81% in a short time. The experiment also compares the performance of the network after the transfer learning based on six kinds of pre-trained networks, and the result shows that the recognition rate of the transfer network based on VGG16 is the highest, which can reach 99.48%. It is verified that the deeply convolutional neural network has certain noise tolerance ability, and can ensure a high recognition rate in the background of strong noise.

Design and Experimental Research of Low-Frequency Broadband Multi-Beam Sonar System

YUE Lei, JIANG Chun-hua, LUO Song, WANG Xin-yi, NA Jie-si, MA Xue, LIU Bao-jun, HE Qi-yu, DING Ming-hui

2020, 28(1): 097-106. doi: 10.11993/j.issn.2096-3920.2020.01.014

[Abstract](817) [PDF 4846KB](160)

Abstract:
The present situation and characteristics of the acoustic detection technology and equipment for submerged and buried targets, including sub-bottom profiler, synthetic aperture sonar, and three-dimensional imaging systems, are summarized, and their problems and shortcomings are analyzed. In view of the detection requirements for length-finite submerged and buried pipeline targets, the reverberation suppression and spatial discrimination ability of the low-frequency broadband multi-beam sonar for detecting submerged and buried pipeline targets are analyzed. The technical specification, usage mode, technical scheme of acoustic detection array, signal processing flow, software interface and software processing flow are designed. The characteristics of the designed low-frequency broadband multi-beam sonar are summarized. The lake trial of submerged and length-finite pipeline targets detection verifies that the low-frequency broadband multi-beam sonar can detect the submerged pipeline targets reliably and effectively.

Design of a Broadband Piezoelectric Single Crystal Transducer

LIU Yi-ming, TIAN Feng-hua, SONG Zhe, WANG Tao, LÜ Lin-xia

2020, 28(1): 107-112. doi: 10.11993/j.issn.2096-3920.2020.01.015

[Abstract](421) [PDF 473KB](381)

Abstract:
To improve the low-frequency performance, working bandwidth, transmitting voltage response and recei- ving sensitivity of the composite bar transducer, a broadband piezoelectric single crystal transducer is designed with PMN-PT piezoelectric single crystal as the driving element, and the matching layer technology is adopted to expand its bandwidth. The finite element software is employed to establish finite element models of the piezoelectric single crystal transducer and a similar piezoelectric ceramic transducer, and quantitative evaluation of single crystal PMN-PT materials is completed. Pool test shows that compared with the transducer with PZT-4 material, the designed broadband transducer has lower frequency and wider bandwidth, and its transmission voltage response is 3~5 dB higher and receiving sensitivity is 1~12 dB higher, indicating that the designed transducer has better acoustic detection performance.

Application of Feature Selection Based on GA-KPCA in Underwater Target Recognition

YAN Liang-tao, XIANG Xiao-li

2020, 28(1): 113-117. doi: 10.11993/j.issn.2096-3920.2020.01.016

[Abstract](369) [PDF 494KB](177)

Abstract:
The complexity of underwater radiated acoustic field and underwater acoustic channel results in intercoupling of the noise signals received by sonar, modulation distortion, and strong nonlinearity. In this paper, the kernel function is used to map the nonlinear data of the original feature space to the high-dimensional feature space; the principal compo-nents analysis(PCA) method is used to extract the features from the high-dimensional feature space, and the genetic algorithm(GA) is used to optimize the kernel parameters, thus an underwater target feature selection method based on GA-kernel principal components analysis(KPCA) is established. Actual sample data validation shows that, to a certain extent, this method compensates the insufficiency of the traditional linear PCA method in dealing with nonlinear data, and it has higher recognition accuracy.

2020 Vol. 28, No. 1

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