水下无人系统学报

Mapping Relationship between Wave Parameters and Wave-Driven Velocity of Wave Glider

SUN Xiu-jun, LI Zong-xuan, YANG Yan, ZHOU Ying, SANG Hong-qiang

2020, 28(5): 471-479. doi: 10.11993/j.issn.2096-3920.2020.05.001

[Abstract](271) [PDF 1658KB](319)

Abstract:
It is difficult to accurately reflect the mapping relationship among the wave height, wave period under real sea con-ditions, and wave-driven velocity of a wave glider via computer simulation or water tank experiments. In this study, wave height, wave period, velocity, and position coordinate data were obtained using an acoustic Doppler current profiler(ADCP), wave sensor, and global positioning system(GPS), which were installed on a Black Pearl wave glider. The wave-driven velocity vector of the wave glider is calculated by subtracting the profile velocity vector from the ground velocity vector. The profile velocity vector is directly measured using the ADCP, whereas the ground velocity is measured using the ADCP bottom tracking mode and GPS data. Finally, scatter plots of wave-driven velocity, wave height, and wave period are constructed, and the mapping relationship between wave-driven velocity and wave parameters is determined by fitting curves. The deduced wave-driven velocity in this study is positively correlated with the wave height and negatively correlated with the wave period within a certain range of parameters. The relationship serves as an important basis for the optimal design of the wave dynamic transfer mechanism of a wave glider.

Optimal Approach of Weak Underwater Acoustic Signal Detection Based on Passive Time-Reversal Stochastic Resonance

XIAN Min-yuan, ZHAO Chun-yan, HE Ke, WANG Dong-shi, FU Jin-bao, Lü Xiao-peng, JI Zhao-sheng

2020, 28(5): 480-496. doi: 10.11993/j.issn.2096-3920.2020.05.002

[Abstract](177) [PDF 746KB](166)

Abstract:
The multipath effect in channel transmission and the low signal-to-noise ratio(SNR) of the received signal significantly increases the difficulty in underwater weak signal detection. Herein, based on a theoretical model of underwater acoustic rays, an optimal detection method for underwater weak signal parameters based on passive-time-reversal stochastic resonance(PTR-SR) is proposed. This method combines the advantages of time-reversal and stochastic resonance, uses a time reversal method to transform underwater multipath interference into signal gain, and uses the stochastic resonance method to transfer part of the noise energy into the target signal. Furthermore, by deducing the optimal solution of the gain amplitude parameter A_sr, the SNR gain of the received signal in the lower SNR region is further improved, and a simulation is performed. The simulation results show that the PTR-SR combined detection method performs better than the traditional method. It can effectively enhance the signal input–output SNR gain and detect weak signals more effectively at lower SNRs, providing a new theoretical and technical support for underwater weak signal detection technology.

Near-field and Far-field Scattering Characteristics of Underwater Low-frequency Spherical Acoustic Wave

ZHANG Jian, ZHOU Qi-zheng, WANG De-shi

2020, 28(5): 487-495. doi: 10.11993/j.issn.2096-3920.2020.05.003

[Abstract](232) [PDF 839KB](251)

Abstract:
To investigate the scattering mechanism of underwater low-frequency acoustic waves, a uniform asymptotic solution of near- and far-field acoustic pressures is derived. First, the infinite series solution of the scattering acoustic pressure for low-frequency spherical acoustic waves encountering spherical obstacles such as soft and hard impedance is provided. Based on the assumptions of low frequency, near- and far-field, the approximate forms of the Bessel and Hankel functions are employed to derive the asymptotic solution. By assuming that the acoustic source is near the scatter, a uniform asymptotic solution of the near- and far-field scattering acoustic pressures is derived. Subsequently, the near- and far-field scattering characteristics of a spherical acoustic wave are investigated. The results show that the low-fre- quency scattering acoustic pressure can be expressed as a superposition of fields because of a monopole source and dipole sources, the uniform asymptotic solution derived is consistent with the classical solution at low frequency. When the source is near the obstacle and the receiver is far from the source or obstacle, the echo strength of the soft sphere is shaped like a circle, whereas those of the hard and impedance spheres are shaped as “gourds”. When the source is far from the obstacle and the receiver is near the source, the echo strengths are related to the shape of the incident wave. The results are useful for controlling acoustic scattering and detecting low-frequency waves of underwater targets.

Sliding Mode Control of ROV Propeller Based on Duct Propeller Load

XU Peng-cheng, ZENG Qing-jun, CHEN Yao-wei, ZHU Zhi-yu, DAI Xiao-qiang, LING Hong-jie

2020, 28(5): 496-504. doi: 10.11993/j.issn.2096-3920.2020.05.004

[Abstract](571) [PDF 2105KB](132)

Abstract:
To satisfy the requirements of motion control and propulsion system control of a self-developed underwater assisted oil recovery remote operated vehicle(ROV), a new type of ROV propeller permanent magnet synchronous motor (PMSM) sliding mode controller based on the load characteristics of a ducted propeller is proposed herein. The ROV and its propulsion system are expounded, a mathematical model of the ROV propulsion system based on the duct propeller load characteristic is established, and the ROV propulsion motor speed controller based on the global fast terminal sliding mode algorithm is designed. Through simulation analysis, the dynamic response performances of PMSMs of different control algorithms based on the duct propeller load are analyzed. The simulation results show that the proposed new sliding mode controller enable the ROV propulsion system to achieve a faster dynamic response speed and better stability. Furthermore, the global fast terminal sliding mode controller designed in this study is verified in terms of its feasibility and effectiveness when applied to an underwater propulsion control system for underwater-assisted oil recovery.

Path Planning of Multi-AUVs Based on Multi-ant Colony Cooperative Search Algorithm

YUE Wei, XI Yun, GUAN Xian-he

2020, 28(5): 505-511. doi: 10.11993/j.issn.2096-3920.2020.05.005

[Abstract](904) [PDF 570KB](186)

Abstract:
To solve the cooperative search problem of multiple autonomous undersea vehicles(AUVs) in an unknown en-vironment without considering the sonar detection distance and single optimization index, a collaborative path planning algorithm for multi-ant colonies based on prior information is proposed based on the comprehensive effect of detection distance on target discovery probability, AUV turning, and collision avoidance threat. First, based on the prior information of the target distribution, a target probability distribution map based on the grid of the search area is established. Subsequently, the pheromone concentration is initialized based on the probability distribution of the target, and the prior information is used to guide ant searches. State transition rules are designed based on the target probability size to maximize the probability of finding the target. Finally, the pheromone concentration is updated based on the advantages and disadvantages of the search path solution, and the effectiveness of the search strategy is verified by simulation.

Robotic Fish Motion Control Algorithm Based on Visual Information Loss

XIE Jing-peng, LI Zong-gang, DU Ya-jiang, GE Li-ming

2020, 28(5): 512-519. doi: 10.11993/j.issn.2096-3920.2020.05.006

[Abstract](215) [PDF 2934KB](120)

Abstract:
To solve the problem of visual information loss in multi-robotic fish motion control, a motion compensation control algorithm is proposed. First, for the recognition status of a robotic fish, a judgment strategy using the secondary filtering method based on event frequency is expounded. Subsequently, the mathematical model of the straight-line tracking method with semi-closed loop control is established. Through the calculation and planning of an action matrix, the approximate linear motion control of the robotic fish is realized. Subsequently, based on the time–angle relationship, the circle tangent method is derived to realize the turning motion control of the robotic fish in the time domain. Simulation and experimental results show that the proposed algorithm can solve the motion control problem of bionic robotic fish when visual information loss occurs.

Target Tracking Error Simulation and Analysis of Acoustic Homing Torpedo

YANG Xiang-feng, XIONG Shu-zhen, SHI Lei

2020, 28(5): 520-525. doi: 10.11993/j.issn.2096-3920.2020.05.007

[Abstract](766) [PDF 645KB](278)

Abstract:
Active acoustic homing torpedo target tracking exhibits the characteristics of base motion and time-varying observation. When using the Kalman filtering method to track the target, it is necessary to use the torpedo navigation attitude parameters and torpedo detection target information as well as transform the torpedo detection target coordinate from the torpedo coordinate system to a geodetic coordinate system through coordinate transformation. Therefore, the detection error of the homing system and the attitude error of the navigation and positioning system affect the tracking performance. Herein, the source and transmission paths of the target tracking error of an active acoustic homing torpedo are analyzed. The tracking performances of the yaw angle error, torpedo speed error, and detection error are simulated and analyzed. The simulation results show that the yaw angle error does not significantly affect the target speed estimation and course angle estimation. The torpedo speed error is linearly transmitted to the target, the velocity estimation error is equal to the torpedo speed error, and the torpedo speed error does not affect the course. The detection error can be eliminated via filtering, and the motion parameters can effectively approximate the true value after multibeat filtering.

Parameterized Analysis and Optimization of Undersea Vehicle Resistance

LIU Feng, LIANG Xu, MIAO Yi-rani, TU Chao-hua, ZHAO Yan-kai

2020, 28(5): 526-531. doi: 10.11993/j.issn.2096-3920.2020.05.008

[Abstract](201) [PDF 977KB](185)

Abstract:
In this study, the resistance performance and analysis efficiency of an undersea vehicle is improved, and a parameterized analysis flow of resistance is designed. The second development of STAR-CCM+ software is performed using the Java language. The reading and processing of control parameters and calculation results in the design process are realized using iSIGHT software, and the parameterized modeling and analysis of undersea vehicle resistance is realized. The optimal Latin hypercube is used to generate sample points, and the corresponding direct route resistance value is obtained through parameterized analysis. The sensitivity and main effect of design variables on the direct route resistance are analyzed. The sample points are fitted using a response surface model, and an approximate model of direct run resistance with a high fitting accuracy that satisfies engineering requirements is obtained. The optimal model of the direct route resistance of the underwater vehicle is established, and the nonlinear quadratic programming method is applied to solve the problem, unlike the initial scheme. The direct route resistance reduced by 10.78%, and the design efficiency improved significantly.

Simulation of Phase Transition Process of Underwater Thermal Glider Based on FLUENT

LIU Hong-jin, HU Yu-li, YANG Wei, HAO Ze-hua

2020, 28(5): 532-537. doi: 10.11993/j.issn.2096-3920.2020.05.009

[Abstract](154) [PDF 1219KB](277)

Abstract:
The solid-liquid phase transition is key to enable a thermal glider to absorb and utilize the ocean temperature difference energy. The solid-liquid phase transition process is affected by many factors. Herein, based on the existence of natural convection, the effect of pressure on the solid-liquid phase transition process of a thermal glider is introduced. The simulation model of phase-change heat transfer in the heat pipe of an underwater thermal glider is established, and the heat pipe heat-transfer process under different pressures is simulated using ANSYS FLUENT 18.0 software. It is discovered that the pressure can change the melting temperature of the material and affect the phase transformation. With the increase in pressure, the melting temperature of the material increases, and the time required to achieve complete melting under the same temperature increases however, the time required for solidification decreases. If the melting point is higher than the temperature of the warm water layer, then the phase-change material cannot complete the phase-change process, and the thermal glider will not be able to operate stably. The simulation results facilitate the study of the phase-transition process of underwater thermal gliders.

Numerical Simulation and Analysis of Hydrodynamic Scale Effect of Pump-jet Propulsor

SUN Ming-yu, DONG Xiao-qian, YANG Chen-jun

2020, 28(5): 538-546. doi: 10.11993/j.issn.2096-3920.2020.05.010

[Abstract](195) [PDF 3956KB](154)

Abstract:
Scale effects are important in accurately predicting the hydrodynamic performance of pump-jet propulsors. By solving the Reynolds-averaged Navier-Stokes equation, the open-water performances of model-scale pump-jet propulsors and full-scale pump-jet propulsors are simulated, and the hydrodynamic difference caused by scale effect is analyzed. It is discovered that the differences between model- and full-scale hydrodynamic performances are mainly attributable to the rotor furthermore, the scale effect is reflected in the hydrodynamic performance of each component of the propulsor, i.e., the scale effect of the duct is the most significant, whereas that of the rotor contributed the most to the overall hydrodynamic performance of the propulsor.

Comparative Analysis on Control Mode of Low-Speed High-Torque Motor Used in UUV

LIU Ya-bing, WANG Hai-qing, HU Qin-long, WU Song, HU Li-min, ZHANG Guo-nan

2020, 28(5): 547-554. doi: 10.11993/j.issn.2096-3920.2020.05.011

[Abstract](225) [PDF 1271KB](251)

Abstract:
This paper focuses on the study of a low-speed high-torque propulsion motor used by unmanned undersea vehicles. The key technologies of the inverter using square-wave and sinusoidal drive modes are introduced. The method of advance commutation by a rotary variable differential transformer in the square-wave drive mode and a variable control method based on voltage feedback in sinusoidal drive mode are proposed. The results from multinomial experiments show that the sinusoidal drive mode offers more advantages in terms of current pulsation, efficiency, and motor temperature. The phase current can be decreased using the advance commutation method in square waves. The motor functioned well, even when the voltage of battery packs decreased from the use of the variable control method.

Active Acoustic Bait Simulation System Based on COMSOL

TANG Li-yuan, WANG Hai-tao, WANG Bin

2020, 28(5): 555-562. doi: 10.11993/j.issn.2096-3920.2020.05.012

[Abstract](541) [PDF 1660KB](282)

Abstract:
The “receiving and sending” mode is one of the important symbols of the intelligentization of modern active acoustic bait. To solve the distortion of the transmission function of a receiving/transmitting acoustic field and the leakage of the transmitting string under this mode, an active acoustic bait array element domain signal simulation system is established using COMSOL in this study. The system architecture and modular design ideas are described, and six major functional modules are designed: model building, acoustic finite element, marine environment, receiving, transmitting, and signal processing modules. The simulation algorithm of the target/simulated target’s scattering acoustic field transfer function based on the finite-element and plate-element methods is introduced it provides signal processing functions such as spectrum analysis, time–frequency analysis, and envelope extraction. The transfer function between the input voltage of the acoustic bait receiver and the output voltage of the transmitter is simulated by establishing a mathematical model of the acoustic field cross-leak feedback between the transmitter and receiver in the acoustic vibration coupling state. The system is deployed on a cluster computer through a COMSOL server. Unlike existing studies pertaining to “receiving and sending” technology, the effect of the acoustic and vibration coupling of the equipment is considered, and the complete bait operating process using the array time-domain signal as the result is simulated in this study. A specific code is implemented in the background, the interactive interface is simple and easy to operate, and the modules communicate through shared files, which are universal and extensible. After several runs, the system performance stabilizes and the calculation speed is high. By comparing the simulation results and theoretical solutions of the classic spherical electronic cabin model, the accuracy of the system is verified.

Operational Effectiveness Evaluation of Anti-Torpedo Torpedo Weapon System Based on Simulation

CAO Meng, ZHAO Qi, JIANG Ji-jun

2020, 28(5): 563-570. doi: 10.11993/j.issn.2096-3920.2020.05.013

[Abstract](198) [PDF 406KB](164)

Abstract:
To address the necessity of operational effectiveness evaluation for an anti-torpedo torpedo weapon system (ATTWS), an index system is established based on analyzing the operational process and applying an improved subjective and objective weight calculation algorithm to calculate index weights. Subsequently, a simulation is performed to evaluate the operational effectiveness. Operational scenarios are implemented in the simulation. Finally, based on simulation examples, evaluation methods applicable to ATTWS operational effectiveness evaluation are investigated. Thereafter, the result of the operational effectiveness simulation is analyzed and conclusions are provided. This study provides conditions for the comprehensive evaluation of operational effectiveness based on the battlefield countermeasure environment and can support effectiveness evaluations in different environments.

Anti-ship Torpedo Damage Effectiveness Evaluation-index System

LI Hong-tao, XI Hui-wei, LI Jia-tong

2020, 28(5): 571-576. doi: 10.11993/j.issn.2096-3920.2020.05.014

[Abstract](162) [PDF 387KB](167)

Abstract:
The damage effectiveness of an anti-ship torpedo is mainly determined by three factors: warhead, target, and torpedo and target encounter conditions. To construct an evaluation index system of damage effectiveness based on the damage mechanism of contact explosion and close-range non-contact explosion for anti-ship torpedoes, the effects of explosion, water environment, warhead, charge, and target ship on explosive power are investigated to determine the explosive power index. Subsequently, the effects of explosion site, explosion distance, depth of attack, and impact angle on target damage are investigated to determine the torpedo and target intersection condition index. Finally, the effects of ship hull parameters, hull material, protection structure, and anti-sinking property on ship survivability are investigated to determine the vulnerability index of ship structure.

Application of Reliability Enhancement Test for Torpedo Products

PANG Duo, CHEN Huan, CAO Meng, ZHANG Yue-qing

2020, 28(5): 571-576. doi: 10.11993/j.issn.2096-3920.2020.05.015

[Abstract](176) [PDF 393KB](222)

Abstract:
The reliability enhancement test induces step stress to stimulate the failure of products. It has a short period and reveals failure rapidly, and is a useful method for increasing the inherent reliability of products. However, a reliability enhancement test for torpedo products has not been fully popularized. To solve this problem, based on the characteristics of torpedo products and the technology of reliability enhancement test, the specific method of reliability enhancement test applied to torpedo products is given in this study, including the reliability enhancement test process, confirmation of test products, analysis of environmental stress and typical test profiles. The method is discovered to be logical and feasible it can serve as a reference for the reliability enhancement test of torpedo products.

2020 Vol. 28, No. 5

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