水下无人系统学报

Feasible Region Programming Method and Analysis of Influential Factors for Design of Torpedo Nose Cap

QIAN Li-xin, LIU Fei, HU Yan-hui, ZHAO Jian-bo

2016, 24(3): 161-165. doi: 10.11993/j.issn.1673-1948.2016.03.001

[Abstract](703) [PDF 649KB](395)

Abstract:
A feasible region programming method for designing frangible nose cap with tangent ogive is established by analyzing the aerodynamic loading in the air and the impulsive loading during water entry process. The method is employed to investigate the impact dynamics of a nose cap at water entry and the feasible region design with given boundary conditions. Furthermore, water-entry experiments of the nose cap are conducted. The results indicate that the feasible region defines the theoretical boundary of nose cap structure, the flight speed in the air determines the critical water-entry velocity in feasible region and the width of the region, and the ogive's length-to-diameter ratio has significant influence on the width of feasible region.

Autonomous Abutting Joint Flow and Control Algorithm for AUV Based on Ultra-short Baseline

ZHAO Chao-wen, ZHANG Song, LI Hui

2016, 24(3): 166-171. doi: 10.11993/j.issn.1673-1948.2016.03.002

[Abstract](1164) [PDF 1483KB](732)

Abstract:
Because of the energy carried by an autonomous underwater vehicle(AUV) is limited, the AUV has to au-tonomously navigate to underwater base station after finishing a task. This paper analyzes current situation of the underwater base station, especially analyzes the abutting joint principle of the subsumption station, and proposes an abutting joint flow based on ultra-short baseline. Firstly, according to different guidance information and the distance between AUV and abutting joint station, autonomous abutting joint process of an AUV is divided into four phases, i.e. long-range phase, middle-range phase, short-range phase and end-range phase. Secondly, characteristics, working flow and control algorithm of every autonomous abutting joint phase are analyzed in detail. Finally, these control algorithms are simulated via VS2008, and the AUV is tested in a lake. The results show that the proposed autonomous abutting joint flow and algorithm are feasible, and they may have a good prospect in engineering applications.

Hydrodynamic Characteristics of Conical Cavitator with Fins

LI Fu-yuan, DANG Jian-jun

2016, 24(3): 172-176. doi: 10.11993/j.issn.1673-1948.2016.03.003

[Abstract](1238) [PDF 583KB](460)

Abstract:
To explore the hydrodynamics of a conical cavitator with fins, numerical simulation is performed to obtain the hydrodynamics of a conical cavitator with different fins. The obtained simulation data are analyzed, and the variations of drag and lift forces on the conical cavitator with the angle of attack, as well as the influences of the wedge angle, shape of fin, and cone angle of cavitator on the hydrodynamics, are achieved. The conversion formula between wedge angle and attack angle is verified with the simulation data. Simulation results show that the conical cavitator with proper fins can improve the control force without increasing the drag to an underwater vehicle.

Detection Range Prediction of Passive Sonar in Shallow-water Area Based on the HMG Method

GAO Fei, PAN Chang-ming, LI Sheng-quan, SUN Lei, CHEN Fu-sen

2016, 24(3): 177-183. doi: 10.11993/j.issn.1673-1948.2016.03.004

[Abstract](994) [PDF 711KB](496)

Abstract:
A research is conducted by combining experiment data and simulation model based on the hydrology meteor-ology geology(HMG) method to evaluate the influence of the underwater acoustic environment effect on sonar detection range. Firstly, the HMG prediction theory is discussed based on the sonar equation, and a sonar parameters combination expression is proposed. Then, the ocean environment background field is constructed combining with shallow-water acoustic survey in the East China Sea, and its acoustic parameters distribution of the water and boundary are analyzed. Finally, the Kraken’s numerical acoustic transmission model and the empirical model of wind-generated noise are verified with measured data, and the passive sonar detection range is simulated for different wind speeds and sound speed profiles with the HMG method. The results show that: 1) the HMG method can simulate the effect of the underwater acoustic environment effect on sonar detection range; 2) the transmission loss and ambient noise increase with wind speed at sea surface, which decreases the sonar detection range; and 3) the sound speed profile influences detection range by affecting acoustic boundary loss, and the detection range gets the biggest in vertically uniform sound speed environment. This research may provide a reference for the underwater passive sonar detection and the stealth of an underwater vehicle.

Availability Analysis on Application of Active Acoustic Homing to Anti-ship Torpedo

HE Xin-yi, CHEN Jing, GAO He, LU Jun

2016, 24(3): 184-188. doi: 10.11993/j.issn.1673-1948.2016.03.005

[Abstract](1190) [PDF 982KB](466)

Abstract:
To understand the availability of applying active acoustic homing to an anti-ship torpedo, the operational en-vironment and object of the torpedo are analyzed, and conclusion is drawn that active acoustic homing should not be taken as a main technology for anti-ship torpedo homing. Main reasons are as follows: 1) the thermocline may lead to the problem that torpedo′s acoustic pulse signal cannot establish acoustic contact with a surface ship, thus resulting in the failure of anti-ship attack; 2) the diffuse reflection effect and high radiation noise which come from surface ship’s evasive maneuvering after receiving torpedo alarm may result in loss of active acoustic homing against ship; 3) mirror effect of the sea surface will significantly increase the false alarm rate of active acoustic homing against ship. In addition, according to the operational requirements for an anti-ship torpedo and the development of related technology, the development trend of anti-ship torpedo homing technology is prospected.

Design of Vector Hydrophones for Suspended Anti-torpedo Depth Charge

LIU Qing-Hui, DENG Nan-Ming, WANG Hao

2016, 24(3): 189-193. doi: 10.11993/j.issn.1673-1948.2016.03.006

[Abstract](820) [PDF 339KB](432)

Abstract:
A cylindrical vector hydrophone for suspended anti-torpedo depth charge was designed to achieve the inter-ception of an incoming torpedo. The measurement principle of a co-oscillating cylindrical vector hydrophone was derived based on the receiving and responding acoustic wave models of a rigid cylindrical swing receiver. The interrelationship among the parameters of a co-oscillating cylindrical vector hydrophone which uses piezoelectric accelerometers was analyzed by simulation. And the vector hydrophone′s technical performance parameters were selected and designed to meet usage requirements of the suspended anti-torpedo depth charge. Simulation results show that in the allowances of sensitivity and phase difference, less strict geometrical dimension requirement of the acoustic rigid moving cylinder may facilitate the design of the co-oscillating cylindrical vector hydrophone of suspended anti-torpedo depth charge.

Effects of Two-axis Turntable Position Errors on Accelerometer Calibration Accuracy

CAO Ya-li, ZHANG Fu-bin

2016, 24(3): 194-199. doi: 10.11993/j.issn.1673-1948.2016.03.007

[Abstract](1183) [PDF 286KB](405)

Abstract:
The accuracy of a strapdown inertial navigation system(SINS) directly determines the underwater navigation accuracy of an autonomous underwater vehicle(AUV). In this paper, the two-axis turntable position errors(including hori-zontal installation error, gradienter leveling error, non-orthogonal installation error, etc.) were analyzed, and the turntable errors were defined directly in the turntable coordinate system. According to the existing of inertial device error model, six ideal position calibration paths were selected, real projection value of acceleration of gravity in the coordinate system was obtained, the calibration process with turntable error was derived by using analytic method(without considering the relationship between the errors), and calibration error estimation of parameter was accomplished through reasonable design of calibration path and effective mathematical algorithm. Simulation calibration results show that the proposed calibration method is feasible in a short time, and the calibration error parameter value is within the reasonable error range, which proves the correctness of the proposed calibration path scheduling algorithm.

Near-Surface Depth Control Based on Robust Backstepping Sliding Mode for Small Underwater Vehicles

SHAO Zhi-yu, WANG Ya-jie

2016, 24(3): 200-205. doi: 10.11993/j.issn.1673-1948.2016.03.008

[Abstract](797) [PDF 680KB](421)

Abstract:
Near-surface motion state of a small underwater vehicle is influenced by wave disturbance to lower the control accuracy. To suppress wave disturbances, a longitudinal model of the small underwater vehicle was built in this study, and a depth controller was designed with the control method of robust backstepping sliding mode. A near-surface wave disturbance model and a depth control model were established to simulate the depth control method by using Matlab/Simulink. Simulation results show that the designed depth controller is easy to be implemented with small overshoot, short setting time and strong robustness. This study may provide theoretical and technical support for solving the problem of wave disturbance in depth control.

Development Trend of Power Battery for Torpedo Based on Equipment Demand

GAO Xin-long, WANG Yu-xuan, LI Xue-hai

2016, 24(3): 206-210. doi: 10.11993/j.issn.1673-1948.2016.03.009

[Abstract](1095) [PDF 227KB](1038)

Abstract:
With the development of torpedo weapon towards long range, high speed and informatization, the research on torpedo power battery encounters new challenges. This paper describes the development features of torpedo weapon, reviews the development of the high energy batteries, e.g. lithium-silver oxide battery, lithium-carbon fluoride battery, hydrogen-oxygen fuel battery, and thermoelectric battery, and analyzes their applications to torpedo power source. Sub-sequently, three development trends of torpedo power battery are forecast as follows: 1) sufficiently increasing performance potential for the aluminum-silver oxide battery; 2) designing new-type high power battery; and 3) developing integrated power source technology.

Modeling and Simulation of Underwater Propulsion System Based on Hydroreactive Aluminum Metal Fuel

LU Jun, HAN Yong-jun, MA Wei-feng, GAO Yu-ke, GUO Zhao-yuan, LI Xin

2016, 24(3): 211-216. doi: 10.11993/j.issn.1673-1948.2016.03.0010

[Abstract](896) [PDF 487KB](1195)

Abstract:
Hydroreactive aluminum metal fuel can greatly increase the range of an unmanned underwater vehicle due to its high energy density. In this paper, the working principle of the propulsion system is introduced. The system is modeled based on the thermodynamics analysis. An iteration method is proposed for the solution of the model. Using the model, the key thermal parameters of the system are calculated, and their impacts on system performance are analyzed. Simulation results indicate that the proposed system is superior to the existing system powered by lithium battery. In addition, the system heat efficiency can be further improved by optimizing its key thermal parameters.

Finite Element Analysis of Low-Noise Seawater Pump Based on ANSYS Workbench

LI Yong-dong, ZHANG Hai-ying, MA Xiao-lu, BAI Kun-xue, GAO Ai-jun

2016, 24(3): 217-221. doi: 10.11993/j.issn.1673-1948.2016.03.011

[Abstract](783) [PDF 918KB](835)

Abstract:
Finite element method is applied in static and dynamic analyses of low noise seawater pump′s key components for a torpedo. The force and vibration characteristics of the key components in specific conditions are acquired through ANSYS Workbench, and the continuing dynamic characteristics of ring gear are predicted through harmonic response analysis. This study may provide a theoretical support for design and test of low noise seawater pumps, and is helpful for shortening development period, saving costs and improving design quality.

A Model of Torpedo Storage Life Test under Temperature Stress

ZHANG Bai-yong, LIU Kai, SUN Jiong, LI Hong-sheng, LIN Yang

2016, 24(3): 222-226. doi: 10.11993/j.issn.1673-1948.2016.03.0012

[Abstract](582) [PDF 307KB](471)

Abstract:
To estimate torpedo storage life, the main environmental factors influencing torpedo storage life were analyzed and the accelerated life test of a torpedo under temperature stress was conducted. In addition, Arrhenius model was used to estimate the torpedo storage life. Methods for the accelerated life test and for determining parameters of Arrhenius model were presented, and accelerated life tests of the selected main components affecting torpedo storage life were performed to validate these methods. The results show that the research in this paper is efficient for assessing the accelerated life test and estimating the torpedo storage life at room temperature.

Test Methods for Acoustic Counter-Countermeasure of Torpedo Based on Different Evaluation Grade

QI Li-xin, WU Jian-lan

2016, 24(3): 227-234. doi: 10.11993/j.issn.1673-1948.2016.03.013

[Abstract](563) [PDF 287KB](504)

Abstract:
On the basis of different evaluation grade, two different test methods for acoustic counter-countermeasure of a torpedo were designed. The first method verifies the tactical and technical indexes and function of acoustic coun-ter-countermeasure of a torpedo via sea trial, and the second method evaluates the torpedo operational capability of acoustic counter-countermeasure evaluation based on combination of sea trial and simulation test. The support conditions and implementation procedures of the tests, as well as the method or standard for evaluation of test results, were presented. The design ideas of the two tests can be applied to finalizing test of a torpedo for evaluating both tactical/technical indexes and operational capability of acoustic counter-countermeasure, and the implement procedures of the proposed test methods are economical and feasible. This study may provide a reference for test and evaluation of acoustic counter-countermeasure of a torpedo.

Analysis on Flow Field in Launch Valve of Submarine′s Torpedo and Missile Launch System under Emergency Launch Condition

WANG Xian-ming, DUAN Hao, WANG Yun

2016, 24(3): 235-240. doi: 10.11993/j.issn.1673-1948.2016.03.014

[Abstract](759) [PDF 2213KB](305)

Abstract:
The purpose of launch valve in submarine′s torpedo and missile launch system is to control the flow and pressure of gas, so as to ensure the accuracy of launching process. In this paper, a mathematical model of flow field in the launch valve under emergency launch condition is established with commercial CFD software, and the model is simulated by means of the shear stress transmission(SST) model and dynamic mesh technique. Simulation results show detailed and intuitive distributions of transient pressure and transient velocity of the interior flow field at all stages. These results can provide a theoretical basis for optimization design of channels of the launch valve, and can also provide a reference for research of vibration and aerodynamic noise of the submarine launch system.

2016 Vol. 24, No. 3

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