水下无人系统学报

Design of Torpedo Head without Cavitation and Performance Analysis Based on Computational Fluid Dynamics

JIN Shuan-bao, WANG Yong-sheng, YANG Qiong-fang

2010, 18(1): 001-5. doi: 10.11993/j.issn.1673-1948.2010.01.001

[Abstract](1236) [PDF 566KB](720)

Abstract:
The superposition of the equal intension of linear source and parallel flow is applied to the shape design of streamline profile of torpedo head to make the maximum pressure reduction coefficient of the torpedo head smaller than cavitation number, therefore the shape of torpedo head without cavitation is designed. The distribution of pressure and the maximum pressure reduction coefficient of the torpedo head are obtain with the theory of hydrodynamics. Then computational fluid dynamics (CFD) and a cavitation model are employed to simulate the performance of the torpedo head. The CFD calculation of pressure distribution on the torpedo head shows an error less than 1% compared with the theoretical result, indicating that the CFD method is valid. In addition, CFD post-processing technology is used to display the cavitation of the torpedo head, demonstrating no cavitation at all. That is to say, the designed torpedo head meet the qualification of no cavitation.

Parameters Optimization of Contra-Rotating Propeller Design

PAN Guang, XIAO Zhi-yong, HUANG Ming-ming, HU Hai-bao

2010, 18(1): 006-8. doi: 10.11993/j.issn.1673-1948.2010.01.002

[Abstract](1502) [PDF 322KB](626)

Abstract:
The purpose of contra-rotating propeller design is to obtain the best open propulsion efficiency(ηD),thus the ship can achieve the designed speed with minimum propulsion power.The propulsion efficiency,noise and cavitation of a contra-rotating propeller can be improved by parameters optimization of contra-rotating propeller. The parameters optimizazion of a contra-rotating propeller design includes the nonlinear restriction optimization of three parameters,i.e.advance coefficient J,disk ratio Ae/Ao and pitch ratio P/D.By using complex method,satisfactory parameters optimization result of the contra-rotating propeller can be obtained.

Positioning Method for Real Initiation Point of Warhead in Sea Trial of Torpedo

WANG Yong-liang, HOU Bao-e, SONG Jing-li

2010, 18(1): 009-13. doi: 10.11993/j.issn.1673-1948.2010.01.003

[Abstract](1709) [PDF 559KB](611)

Abstract:
To accurately measure the real-time position of warhead explosion in sea trial of torpedo and ensure trial effect,we discuss several positioning principles of initiation point of warhead in sea trial of torpedo,compare and analyze the operational effectiveness and applicable conditions of the positioning methods according to the measurements in sea trial,and select two positioning methods by respective shock wave′s bringing-time and shock wave′s walking-time for sea trial of torpedo.Test results verify the universality and the promotion value of the two methods.

Bearing Estimation via Amplitude Comparison of Wide-band Constant Beamwidth Beams for Circular Array

WANG Xiao-yu, YANG Yi-xin

2010, 18(1): 014-20. doi: 10.11993/j.issn.1673-1948.2010.01.004

[Abstract](1788) [PDF 793KB](701)

Abstract:
A method of wide-band beam amplitude comparison for bearing estimation is proposed. In the case of receiving wide-band plane wave signals by circular array, the estimated bearing value can be obtained by constant beamwidth beamforming and the following solution of a group of linear equations with three unknowns for the outputs of the constant beamwidth beams. The new method has smaller bearing estimation error than the wide-band beam amplitude comparison bearing estimation method based on the outputs of conventional wide-band beams of circular array. The simulation results verified the effectiveness and practicality of the proposed method

Research on Homing Mode of Anti-Torpedo Torpedo

HE Xin-yi, XIAO Qing-sheng, ZHANG Chi, LIU Jia

2010, 18(1): 021-25. doi: 10.11993/j.issn.1673-1948.2010.01.005

[Abstract](2167) [PDF 582KB](826)

Abstract:
According to the requirement of anti-torpedo combat and the current technical skills,we propose such homing modes for the anti-torpedo torpedo as active homing, passive homing, pulse detection homing, multistation homing and decoy homing,analyze the features of these modes and calculate the homing ranges.We draw the following conclusions:1) the combined homing mode of ‘long-range pulse detection homing + short-range passive homing’or of ‘long-range pulse detection homing + short-range decoy homing’ is suitable for the anti-torpedo torpedoes equipped on submarine; 2) the combined homing mode of ‘long-range multistation homing + short-range passive homing’ is suitable for the anti-torpedo torpedoes equipped on surface ship.

Real-time Parameter Estimation of Torpedo Homing Signal Based on STFT and its Application

GONG Guo-tian, LI Peng, ZHOU Hao, TANG Heng

2010, 18(1): 026-30. doi: 10.11993/j.issn.1673-1948.2010.01.006

[Abstract](1701) [PDF 579KB](645)

Abstract:
We propose a scheme of torpedo homing signal parameter real-time estimation of acoustic target by adopting the commercial off-the-shelf(COTS) technology,and realize the real-time estimations of pulse carrier frequency,pulse arrival time,pulse width and pulse interval for torpedo homing signal by using short time Fourier transform(STFT). The scheme decreases the data quantity of signal processing, and achieves precise estimation of torpedo homing signal parameter.The function and performance of this scheme are verified by commercial D/A board test.This scheme is developed with lower cost and shorter period,and is easy to be further developed.

Design and Analysis of Built-in Test for Torpedo Homing System

WANG Wei, SUN Qi, XU Jun

2010, 18(1): 031-34. doi: 10.11993/j.issn.1673-1948.2010.01.007

[Abstract](1897) [PDF 500KB](709)

Abstract:
Built-in test(BIT) of torpedo homing system is an important technique for improving testability,maintainability and fault diagnosis capability of torpedo homing system. We introduce a BIT technique for torpedo homing system by using a centralized BIT structure and in-board ROM-BIT hardware and software design method,analyze qualitatively the main function,structure division and design basis,give the flow chart of detection,and present several ways to reduce effectively false alarm rate(FAR) of the BIT.Analysis and calculation results show that the BIT technique meets design requirements with higher falult detection rate(FDR).

Data Fusion Simulation Model of Passive Sonar Target Wake Tracing Based on MGEKF

WANG Yan-kai, DING Yan

2010, 18(1): 035-40. doi: 10.11993/j.issn.1673-1948.2010.01.008

[Abstract](1725) [PDF 585KB](969)

Abstract:
Aiming at the demand of data fusion modeling of target tracing for anti-submarine warfare,a method of integrating the Simulink model into distributed interactive simulation system is presented.To realize the synchronization and data interaction, shared memory and S-function in Simulink are used for data communication.A data fusion simulation model of passive sonar target tracing for only angle measurement system is hence established based on Simulink. Simulation results show that the data fusion simulation model can meet the real-time requirement of distributed interactive simulation system.

Application of Simultaneous Localization and Mapping to AUV

LIU Ming-yong, ZHAO Tao, ZHOU Liang-rong

2010, 18(1): 041-48. doi: 10.11993/j.issn.1673-1948.2010.01.009

[Abstract](2346) [PDF 1036KB](1039)

Abstract:
Simultaneous localization and mapping (SLAM) is vital to worldwide autonomous navigation of autonomous underwater vehicle(AUV).We introduce the latest progress of SLAM algorithm for AUV both at home and abroad,with emphasis on SLAM algorithm in complicated underwater environment,and indicate the difficult problems in SLAM algorithm such as environment description,environment feature extraction,and uncertain information description.Moreover,we sum up some typical implementing methods of SLAM algorithm,and analyze the trends of SLAM algorithm research and development according to the special application environment of AUV.

Simulation of Forward Looking Sonar and Obstacle Avoidance for Autonomous Underwater Vehicle

DU Hui-xin, YAN Wei-sheng, ZHAO Tao

2010, 18(1): 049-52. doi: 10.11993/j.issn.1673-1948.2010.01.010

[Abstract](2174) [PDF 430KB](937)

Abstract:
In order to simulate the process of obstacle avoidance for autonomous underwater vehicle (AUV) in virtual environment, a visual simulation system of obstacle avoidance for AUV is developed on HP workstation based on the software platforms MultiGen Creator and Vega. A simulation method of forward looking sonar (FLS) is proposed. Utilizing the collision vector function proposed by Vega and the user defined volume collision method, the function of FLS is simulated. Meanwhile, using the data measured by sonar, the obstacle avoidance of AUV in virtual environments is achieved.Simulation results show that this visual simulation can make the simulation system approach actual situations, and satisfy the real time requirement of system simulation.

An Orientation Vector Algorithm Based on Improving Angle Increment Extraction

JIAO Liu-fang, XU Hui, SHI Xiu-hua, ZUO Rui

2010, 18(1): 053-56. doi: 10.11993/j.issn.1673-1948.2010.01.011

[Abstract](1382) [PDF 355KB](597)

Abstract:
Application of orientation vector algorithm to angular rate gyro will bring about a big error in converting angular rate into angle increment. We offer an improved three-sample orientation vector algorithm for effectively applying orientation vector algorithm to inertial attitude calculation of the gyro. This improved algorithm uses more nodes in extra two 1/3 periods than the classical algorithm, which makes every available nodes to be used at least five times without adding sample number, leading to a significantly smaller error in converting angular rate into angle increment. Simulation results show that the proposed algorithm can be effectively applied to angular rate gyro.

Modeling and Simulation of AUV Thermal Propulsion System Based on EASY5

LEI Jiang-tao, NIE Wei-dong, QU Da-wei, ZHOU Hua

2010, 18(1): 057-61. doi: 10.11993/j.issn.1673-1948.2010.01.012

[Abstract](1489) [PDF 756KB](722)

Abstract:
The closed-cycle control on thermal propulsion system of autonomous underwater vehicle(AUV)has an advantage over the open-cycle control in AUV intellectualization and trajectory optimization.We establish a model of closed-cycle control on fuel flow of AUV thermal propulsion system with multi-speed based on EASY5,simulate the design condition(steady-state),start-up process, and off-design condition of AUV thermal propulsion system.Compared with the bench test data of AUV,the simulation result shows that the proposed model is reliable and meets the requirement of engineering.

A Small Signal Linear Model of Transformer Isolated Bi-directional DC/DC Converter

WANG Chong-wu, LI Hong

2010, 18(1): 062-67. doi: 10.11993/j.issn.1673-1948.2010.01.013

[Abstract](1215) [PDF 534KB](629)

Abstract:
The transformer isolated bi-directional DC/DC converter is the key component of the traction system in hybrid electrical vehicles(HEVs).We present a linear mathematic model of transformer isolated bi-directional DC/DC converter for HEVs based on the dual time scale theory and the state space average method.The approximate models are important especially for analysis and closed-loop control design of converter circuits. The differential equations, which govern the converter operation, change periodically among a set of linear differential equations because of the switch effect. Based on the time scale a state variable is decomposed into a fast-scale variable and a slow-scale variable. The fast-scale variable of leakage inductance is eliminated by substituting the fast-scale variable into slow-scale variable equations, resulting in reduced order differential equations. From this set of reduced order differential equations a completely averaged model of the isolated DC/DC converter is derived. The simulation results reveal that the circuit and mathematical model are well consistent.The averaged state variables can be treated as a small component plus a DC component, so the averaged variable can be decomposed into a dynamic small signal part and a DC part. This linear small signal model is suitable for control design and analysis at a steady point which is decided by the DC component. A PI controller is designed with this linear model.

Eluding Method of Surface Ship Against Wake Homing Torpedo by Tactic Maneuver

CHEN Yan-hui, SUN Zhen-xin

2010, 18(1): 068-71. doi: 10.11993/j.issn.1673-1948.2010.01.014

[Abstract](1864) [PDF 469KB](748)

Abstract:
The defense against wake homing torpedo is one of the most difficult problems for surface shipIn this paper, the trajectory characteristic and the controlling and guiding principle of wake homing torpedo are discussed,and the elusion rules and application requirements for single surface ship defense are analyzed such as stop, turn, gyration and speed-upThree elusion methods of inserting an escort ship into the wake of capital ship,keeping parallel and narrow wakes, and keeping cross-tracks are proposed for surface ship formation defense.This study may be of benefit to enhancing the defense effectiveness of surface ships against wake homing torpedo, and increase battlefield survivability of surface ships

Discussion on Helicopter Security in Operational Application of Rocket Assisted Torpedo

JIANG Kai-feng, ZHOU Ming, MEN Jin-zhu

2010, 18(1): 072-75. doi: 10.11993/j.issn.1673-1948.2010.01.015

[Abstract](1612) [PDF 392KB](901)

Abstract:
The definition of shooting forbidden and danger zone of a rocket assisted torpedo is discussed on the basis of the guidance station of helicopter. The effects of helicopter guidance angle on detecting error,shooting distance, and shooting forbidden and danger zone are simulated,and rational guidance angle is thus obtained. The results may be of benefit to commanding decision of commanders on helicopters and warships.

An Evaluation Method of Submarine Acoustic Countermeasure Schemes

XIA Kui, ZHENG Yuan, HU Xian-feng

2010, 18(1): 076-80. doi: 10.11993/j.issn.1673-1948.2010.01.016

[Abstract](1696) [PDF 496KB](654)

Abstract:
The evaluation indexes of submarine acoustic countermeasure schemes include the success probability of submarine evasion,submarine electric energy value,evasive time and the launch store ratio of acoustic countermeasure.According to different targets of submarine warfare,we analyze the evaluation indexes about acoustic countermeasure,and present a new comprehensive evaluation method based on multi-index methods including dictionary order,analytic hierarchy process,weighted integral,technique for order preference by similarity to ideal solution(TOPSIS),elimination et choice translating reality-III(ELECTRE-III),preference ranking organisation method for enrichment evaluations (PROMETHEE) ,and so on,as well as concentrating order methods including average order,Borda founction,Dodgson founction, and so on.Simulation results show consistency with actual situation.

2010 Vol. 18, No. 1

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