水下无人系统学报

Review of Power Battery for UUV with Development Trends

CAI Nian-sheng

2010, 18(2): 081-87. doi: 10.11993/j.issn.1673-1948.2010.02.001

[Abstract](2160) [PDF 881KB](736)

Abstract:
The current status and development trends of power battery for unmanned underwater vehicle(UUV) are summarized. The existing primary and secondary batteries can not meet the energy requirements for future UUV owing to insufficient energy density on the basis of comparison between the specific energy of typical electrochemical energy source systems and the required specific energy for long-term UUV development. Aluminum-oxygen semi-fuel cell and proton exchange membrane(PEM) or solid oxide fuel cells (SOFC) have very high specific energy, e.g. liquid hydrogen and liquid oxygen PEM fuel cells have the specific energy of 350~760 Wh/kg, and the dedecane liquid oxygen SOFC has the specific energy of 400~450 Wh/kg.

Motion Elements Solution Method of Underwater Target Based on Modified Polar Coordinates Kalman Filter

LI Jin-long, YIN Shao-ping, DONG Chun-peng

2010, 18(2): 088-90. doi: 10.11993/j.issn.1673-1948.2010.02.002

[Abstract](1810) [PDF 323KB](730)

Abstract:
Addressing the bearing-only positioning of two arrays in a surface ship torpedo defense, we present an algorithm of modified polar coordinates Kalman filter, and analyze the influences of measuring error of bearing data and time-space interrelation on tracking performance. Simulation results show that the modified polar coordinates Kalman filter can quickly and steadily estimate the target motion elements, and enhance the stability of the algorithm. The proposed algorithm is suitable for engineering application.

A Prediction Method for Structural Noise Radiation of Torpedo Based on AutoSEA

LIU Kai, ZHU Shi-jian, DING Shao-chun

2010, 18(2): 091-94. doi: 10.11993/j.issn.1673-1948.2010.02.003

[Abstract](1474) [PDF 514KB](621)

Abstract:
Structural noise radiation prediction is the base and premise of torpedo acoustic design.A statistical energy analysis(SEA) model of torpedo structure is established by using AutoSEA to predict structural noise radiation level of torpedo based on a arithmetic example. Case simulation results show that the SEA method is suitable for the analyses of structural vibration and sound radiation characteristics of torpedo, and can be used in engineering application.

Application of Ethernet to Torpedo Information Communication

ZHANG Jing, WANG Zhi-jie, CAO Xiao-juan

2010, 18(2): 095-98. doi: 10.11993/j.issn.1673-1948.2010.02.004

[Abstract](1403) [PDF 507KB](728)

Abstract:
The Ethernet-based electric systems in torpedo can be conveniently tested, maintained, and updated for the hardware and software. We study the division of Ethernet nodes in torpedo, and propose an Ethernet-based system structure of torpedo to improve torpedo information communication efficiency. By using the configuration of VLAN frame we determine the priorities of information communication in torpedo according to the importance of the information to ensure real-time communication. This method can effectively decrease the collision of information communication from multiple Ethernet nodes to enhance the reliability of communication in torpedo. Moreover, taking typical Ethernet nodes in a torpedo as example, we discuss the segmentation of VLAN, the design of data frame structure, and the determination of information priority.

Techniques for Low Probability of Intercept Sonar

HE Hui-jiang, LIU Jun-kai, LIU Xue-chen, LIANG Zhi-jun

2010, 18(2): 099-103. doi: 10.11993/j.issn.1673-1948.2010.02.005

[Abstract](1874) [PDF 621KB](758)

Abstract:
Based on the equation of low probability of intercept(LPI) factors of sonar, an implementation strategy of LPI signal transmitted technique and bistatic(or multiple bases) technique is presented for the LPI sonar by combining the sonar′s characteristics and the experiences in LPI radar application.Moreover, five LPI sonar signal design techniques, including low frequency signal technique, great time and bandwidth integrator technique, complex-code technique, random or nonlinear system technique, and time-frequency hopping technique are described with emphasis on the factors of space, time, frequency and power. The characteristics of LPI signal wave are analyzed, and several sonar signals with good LPI performance are designed. Simulation results of descending-frequency comb signal and non-linear frequency modulation (NLFM) pulse series signal demonstrate that the designed sonar signals have good LPI performance.

Gerschgorin Disk Estimation Method for Number of Coherent Signals Based on Correlation Toeplitz Matrix

BAI Jun, SHEN Xiao-hong, WANG Hai-yan, ZHANG Ying-feng

2010, 18(2): 104-108. doi: 10.11993/j.issn.1673-1948.2010.02.006

[Abstract](1726) [PDF 517KB](569)

Abstract:
Most algorithms of high direction of arrival(DOA) estimation are on the basis of decomposing characteristic sub-space, so accurate estimation of the coherent signal number is very important to the effectiveness of the algorithms. We present an improved Gerschgorin disk criterion estimation method for the number of coherent signals based on linear equally spaced array. A group of vectors is obtained by correlating each receiving array element with output signal of reference array element. The output Toeplitz matrix of array is constructed with the vector by using Toeplitz matrix structure algorithms, then a decoherent Gerschgorin disk estimation matrix is achieved to estimate the number of coherent signals via Gerschgorin disk criterion. Simulation results show that this method can obtain decoherent signals, extend the application of Gerschgorin radii, and effectively enable the estimation of coherent signal number without losing the valid aperture of the array.

Algorithm of Underwater Passive Target Tracking and Experimental Research Based on Asynchronous Beacon in UUV Range Test

SONG Xu-dong, KANG Wen-yu

2010, 18(2): 109-111. doi: 10.11993/j.issn.1673-1948.2010.02.007

[Abstract](1775) [PDF 308KB](734)

Abstract:
Conventional cooperative underwater measuring method is not sufficient for long-range monitoring of trace in the evaluation and acceptance trial of unmanned underwater vehicle (UUV). We present a new method by obtaining initial position and frequency information which are derived from the global positioning system(GPS) and acoustical transmitter of UUV to estimate UUV motion state parameters with PLE-Kalman algorithm. A tracking algorithm of motion state is proposed by following UUV trace. Simulation results show that the present method can track underwater motion trace of UUV perfectly.

Noise Level Evolution of Low-frequency Ocean Ambient Noise Caused by Ship Sources

SHI Jie, ZHANG Xiao-min, HOU Tie-shuang, HAN Peng

2010, 18(2): 112-116. doi: 10.11993/j.issn.1673-1948.2010.02.008

[Abstract](2070) [PDF 581KB](765)

Abstract:
Ocean ambient noise is the main interference source on all underwater acoustic detection systems.This noise has changed significantly during the past decades, so the spectrum characteristics and rules obtained decades ago can not be used for present research.To better understand the evolution of ocean ambient noise,we summarize the changes of low-frequency ocean ambient noise level caused by ship noise sources over the period from 1950s to present on the basis of a large number of literatures,analyze the trend and cause of ocean ambient change,and draw a conclusion that the rapid increase in ships results in an increase in low-frequency ambient noise level.

Topological Matched Filtering Algorithm for Chaotic Echo of Active Sonar

ZHOU Sheng, DENG Peng

2010, 18(2): 117-122. doi: 10.11993/j.issn.1673-1948.2010.02.009

[Abstract](1776) [PDF 659KB](662)

Abstract:
We present a topological matched filtering algorithm to reduce noise of chaotic echo, which applies embedding theory that reconstruction trace of embedded phase is in topological equivalence with original time series.According to the predefined phase trace of clean chaotic data,we correct the observed noisy chaotic signal in an incremental mode to match this filter as close as possible to the original phase trace.So chaotic signal can be extracted from noisy signal by using the topological matched filter.We optimize the search algorithm with grid search to find nearest neighbors. Simulation results show that this algorithm has a good signal filtering effect even when the signal to noise ratio decreases to 0 dB, and is suitable for white noise, Lorenz chaotic signal and ocean ambient noise. With this algorithm two types of broadband signals can be separated to effectively, recover the original clean chaotic echo.

A Navigation Method for AUV Based on a Single Moving GPS Intelligent Sonobuoy

ZHANG Jia-quan, LIU Ming-yong, LI Wen-bai

2010, 18(2): 123-127. doi: 10.11993/j.issn.1673-1948.2010.02.010

[Abstract](2095) [PDF 487KB](681)

Abstract:
Aiming at the limitation of the traditional autonomous underwater vehicle(AUV) navigation with auxiliary global positioning system(GPS), a method for AUV navigation using a single moving GPS intelligent sonobuoy (GIS) is presented. A novel AUV navigation antenna is designed based on the principle of ultra-short baseline (USBL),therefore the angles and ranges between the GIS and hydrophones of AUV navigation antenna can be measured. Then, via using vector relation and coordinates of the GIS, the measurement equation is obtained. By applying Kalman filter (KF),the coordinates of the hydrophones can be estimated, and then the location of AUV is derived. Simulation results demonstrate that this approach can overcome the shortcomings of the traditional methods, and has good flexibility and stealth, which may provide some theoretical foundations for the accurate long-range localization, path planning and collaborative navigation of AUVs.

Simulation on Movement of Fracture Zone and Cavity for Wake Homing Torpedo

HUANG Wen-ling, SHI Neng-sheng

2010, 18(2): 128-131. doi: 10.11993/j.issn.1673-1948.2010.02.011

[Abstract](1477) [PDF 477KB](664)

Abstract:
The fracture zone and cavity of a ship impose a great effect on a wake homing torpedo, even lead to torpedo reverse guidance, resulting in low torpedo hit probability and high range loss. We analyze the movement law of 3-beam wake homing torpedo in the fracture zone and cavity with different sizes and shapes, and the change law of torpedo′s maximal turning angle with relevant torpedo trajectory through multi-state simulation based on Matlab. Simulation results show that the fracture zone and cavity with smaller sizes (the zone width ≤7.25 m, the cavity radius≤8.24 m) have no effect on torpedo movement, while torpedo turning angle is equal to 0. ;when the turning angle is larger than 0. , torpedo movement is more complex in fracture zone than in cavity, which may provide a reference for trajectory design against fracture zone and cavity of 3-beam wake homing torpedo.

Direct Self-repairing Control of Rudder Fault for AUV

LIU Qi-liang, XU De-min

2010, 18(2): 132-135. doi: 10.11993/j.issn.1673-1948.2010.02.012

[Abstract](1358) [PDF 362KB](691)

Abstract:
To improve the reliability of autonomous underwater vehicle (AUV) control system, a direct self-repairing control scheme based on the model following method is proposed. The AUV can be made to regain its balance working state rapidly by finding a direct self-repairing control law, which will play its role just at the moment of fault and is independent on the certain information of fault. This scheme can achieve complete self-repairing multiple faults upon rudder without fault recognition, make no loss to the performance of AUV when it has no fault, and gain the good ability to avoid the deviation due to disturbance. All of these characteristics of the scheme and conclusions are strictly proved mathematically and supported by simulation results.

Calculation and Visualization of Magnetic-Measurement Sensor Data

ZHOU Feng, LIU Wei-dong, LI Le

2010, 18(2): 136-140. doi: 10.11993/j.issn.1673-1948.2010.02.013

[Abstract](1298) [PDF 643KB](672)

Abstract:
In order to enhance magnetic defense capability,the magnetic field of ship must be degaussed termly.We obtain the conversion of the magnetic field from the practical measuring depth to normal measuring depth, via the magnetic dipole model of ship′s magnetic field. Through converting the model data from the format of spatial points to that of 2D array, the model′s spatial pattern is plotted; and by using the mapping relation between magnetic intensity and gray scale,4D visualization of the model is implemented to provide an exact and direct approach for optimization of the model. The visualization of ship′s magnetic field in both practical measuring depth and normal depth as well as the 3D graph, isodynamic line map and section offer degaussing operators clear instructions to monitor the magnetic-measurement sensors, decide on the intensity of degaussing current, and evaluate the the degaussing effect.

Research on HIL Simulation of Underwater Thermal Power System

LUO Kai, SUN Jun-liang, DANG Jian-jun, WANG Yu-cai

2010, 18(2): 141-145. doi: 10.11993/j.issn.1673-1948.2010.02.014

[Abstract](1702) [PDF 606KB](794)

Abstract:
A real-time simulation computer, a back-pressure simulation device, a load pressure simulation device, a speed adjusting and driving device form the core of a hardware-in-the-loop(HIL) simulation system for an underwater thermal power system. A proportional and a proportional-integral control algorithms are used in the back-pressure and load pressure closed loop control system. We adopt low-pass digital filters to improve the stability of the numerical simulation model, and modify the dynamic behavior of the model to make the HIL simulation system coincide with the actual torpedo thermal power system. Simulation results show that the dynamic simulation precision of the back-pressure, the load pressure and the rotary speed of engine reaches 0.5%, 1.5% and 1.5%, respectively. The system obtains high simulation accuracy.

Simulation on Three Phase PWM Rectifier Using Space Vector Pulse Width Modulation(SVPWM)

WANG Chong-wu, LI Hong

2010, 18(2): 146-151. doi: 10.11993/j.issn.1673-1948.2010.02.015

[Abstract](1539) [PDF 561KB](773)

Abstract:
Space vector pulse width modulation(SVPWM) is one of the most widely used control methods for three phase pulse width modulation(PWM) rectifiers because of its simple configuration and fixed switching frequency. We establish a three phase PWM rectifier model based on SVPWM by using Matlab/Simulink in synchronous rotary coordinates. The SVPWM adopts adjacent discrete vectors to track the continuous reference vector with only restraint to vectors working time rather than vectors sequence in one period during the tracking process. We also analyze the influences of different space vector sequences of the SVPWM on the harmonic wave and power factor of three phase PWM. The results indicate that the three phase SVPWM can output high quality waveform with lower reactive power component, while the two phase SVPWM has low switching frequency and fast response to be suitable for large power rectifiers.

Influence of Restricted Airspace of Rocket-assisted Torpedo on Guidance Station by Shipboard Helicopter

MEN Jin-zhu, ZHOU Ming, WANG Bing-kui

2010, 18(2): 152-155. doi: 10.11993/j.issn.1673-1948.2010.02.016

[Abstract](1787) [PDF 320KB](762)

Abstract:
In order to ensure the security of shipboard helicopter when it guides rocket-assisted torpedo to attack submarine, we analyze the formation cause of restricted airspace in rocket-assisted torpedo firing, and propose a method of dividing the restricted airspace. Consequently, we discuss the guidance station by shipboard helicopter, determine the localizable area of shipboard helicopter to target, and obtain the value range of guidance distance and guidance angle.

Development and Implementation of Virtual Collaborative Training System for Torpedo Technical Preparation

HUANG Bo, ZHANG Ben-sheng, ZHANG Yong, LI Wen-long

2010, 18(2): 156-160. doi: 10.11993/j.issn.1673-1948.2010.02.017

[Abstract](1301) [PDF 774KB](717)

Abstract:
Conventional training of torpedo technical preparation has definite requirements for armament, site and persons, and leads to unavoidable wear and tear of the armament, which will restricts promotion of torpedo technical preparation level. We present a virtual collaborative training system for torpedo technical preparation based on VRML and JAVA, according to the cooperativity and directivity of the technical preparation training, and describe such key techniques as simulation of three dimensional scenes, assembling and disassembling of parts, communication between VRML and JAVA, and operation on two dimensional panels. Application results show that the system is stable and can meet the requirements of actual training, including the collaborative and individual training simulations for different stations and subjects. This system may provide torpedo troops with a scientific and highly effective training platform of torpedo technical support with cheap system maintenance.

2010 Vol. 18, No. 2

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