水下无人系统学报

Evaluation and Analysis of Torpedo Acquisition Management

QIAN Dong, CUI Li, XIAO Chang-mei

2010, 18(5): 321-329. doi: 10.11993/j.issn.1673-1948.2010.05.001

[Abstract](1578) [PDF 231KB](772)

Abstract:
Cost and schedule overruns, performance shortfalls have puzzled the armament acquisition departments for long time. It is necessary to investigate this phenomenon. This paper introduces the armament acquisition management and evaluation method in the United States, and analyzes the evaluation results. According to the statistic data, the torpedo acquisition phenomenon in US is analyzed. Some approaches for improving acquisition process are proposed, including requirement analysis, gradual acquisition, specification determination, technology readiness levels (TRLs) evaluation, and project management maturity levels evaluation, etc.

Numerical Simulation of Unsteady Hydrodynamic in the Process of Underwater UUV Docking

PAN Guang, HE Yu-zhi, WU Wen-hui, HUANG Qiao-gao

2010, 18(5): 330-334. doi: 10.11993/j.issn.1673-1948.2010.05.002

[Abstract](1710) [PDF 352KB](838)

Abstract:
During the docking recovery process of unmanned underwater vehicle(UUV), unsteady hydrodynamic interference occurs between the recovery device and UUV. In this study, the finite volume method (FVM) and the dynamic unstructured mesh technique were used to simulate the docking process of UUV. SIMPLEC algorithm and k-ε model in the Descartes coordinates were also adopted. The rules of hydrodynamic versus distance and the relative distribution of pressure field at different velocity and angle of attack were obtained. By comparing the UUV simulation results with the trial ones in far field, the feasibility of the FVM based on dynamic mash technique in dealing with hydrodynamic interference was verified in the process of UUV docking.

Virtual Reality of Shipborne Dispenser′s Metal Hose Releasing for Wire-Guided Torpedo

WANG Yan, ZHAO Xiong-hui, SHAO Wei

2010, 18(5): 335-338. doi: 10.11993/j.issn.1673-1948.2010.05.003

[Abstract](1831) [PDF 247KB](732)

Abstract:
When torpedo′s wire-guided system releases wires, it needs a length of metal hose to protect the wires. It is hard to test its releasing process and load change due to the high releasing speed. So we establish a model by virtual prototype simulation technology, and analyze the dynamic performance of the metal hose during releasing process. Simulation results agree well with real releasing process. This study may offer a method for the design and test of successive dispensers.

Research on Impact Characteristics of High Speed Vertical Water Entry of an Axisymmetric Body

WEI Zhao-yu, SHI Xiu-hua

2010, 18(5): 339-342. doi: 10.11993/j.issn.1673-1948.2010.05.004

[Abstract](1639) [PDF 266KB](950)

Abstract:
Water entry of an axisymmetric body affects its trajectory, and causes dynamic response of the shell structure and internal components. In this paper, the numerical simulation technology in the large commercial software MSC.dytran is used to simulate the most dangerous vertical water entry of a disk-ogive head axisymmetric body . Hence, the impact and trajectory characteristics and the track of a vertical water entry are achieved. In addition, the early supercavitation phenomenon is simply reviewed. This study may contribute to the design of an axisymmetric body′s head shell for enhancing its resistance of impact, the design of water entry trajectory, and the location of the axisymmetric body.

Application of Encryption Technology to Data Processing System for Torpedo

LUO Gao-qi, GENG Cong

2010, 18(5): 343-345. doi: 10.11993/j.issn.1673-1948.2010.05.005

[Abstract](1158) [PDF 146KB](819)

Abstract:
Data processing system(DPS) is difficult to be extended to the field of torpedo due to the data safe problem. The multi-encryption technology based on the safety requirements of torpedo data processing system is discussed. Using the hybrid encryption algorithm of the international data encryption algorithm (IDEA) and RSA, an encryption scheme of torpedo data processing system is put forward based on the date transmission technology of Hash function. Application results show that this scheme can ensure data safety and accelerate the encryption and decryption.

Design of Ultra-low Power System for Passive Underwater Target Localization

ZHAO Yan-an, ZHANG Xiao-min, YU Yang, MA Ding-kun

2010, 18(5): 346-351. doi: 10.11993/j.issn.1673-1948.2010.05.006

[Abstract](1887) [PDF 323KB](771)

Abstract:
In order to satisfy the needs of ultra-low power, long working time, and high accuracy for new generation passive underwater target localization system, we designed a hardware platform based on ultra-low power devices THS1206 and TMS320VC5509A, and a software platform based on the cross-spectrum algorithm with perfect accuracy and real-time performance. Benefiting from the adoption of much more time delay information, the whole system holds high localization accuracy as well as satisfactory real-time performance. Experimental results show that the designed system gains low power consumption (less than 70 mW), high real-time computation performance and localization accuracy, meeting the special requirements for the new generation passive underwater target localization system.

Underwater Target Modeling Technology Based on Modified Highlight Model

LIU Wen-yuan, ZHAO Jin-hai, SONG Yong-feng, ZHANG Jie

2010, 18(5): 352-356. doi: 10.11993/j.issn.1673-1948.2010.05.007

[Abstract](1954) [PDF 296KB](829)

Abstract:
When a complicated underwater target is irradiated by active sonar, different parts of the target will fall into one another’s shadows along the incidence direction, resulting in cross-coverage and model echo distortion. Aiming at this problem, shading coefficient is introduced based on light projecting principle. A simple solution is presented by deducing the shading coefficient of each component, and the existing highlight model is modified. Simulation results show that the modified highlight model can mirror the submarine echo more accurately, and the experimental data also verify the validity of the model.

Torpedo Guidance Simulation System Based on OpenMP

CHEN Fa-yang, KANG Feng-ju, ZHAO Xiao-dong

2010, 18(5): 357-361. doi: 10.11993/j.issn.1673-1948.2010.05.008

[Abstract](1200) [PDF 240KB](752)

Abstract:
To improve the parallelism degree and execution efficiency of a torpedo guidance simulation system, we introduced parallel programming standard OpenMP and multi-core processors into the simulation system. Software framework of the simulation system was designed using object-oriented programming, and the characteristics and parallel relationship of each task were analyzed. Furthermore, OpenMP was used for parallel processing, and the simulation system operated on Silicon Graphicsn (SGI) workstation with eight-core processors. Simulation results show that the time-consumption on average in single computation step can be reduced to 7~8 ms. Compared with the other torpedo simulation system, our method significantly reduces the computing time, and effectively improves the implementation efficiency of the simulation system.

Design of AUV Navigation Computer System Based on New Type of Floating-point DSP

LIU Ming, ZHANG Yan, XU De-min

2010, 18(5): 362-366. doi: 10.11993/j.issn.1673-1948.2010.05.009

[Abstract](1809) [PDF 190KB](896)

Abstract:
To realize lower cost and power consumption，and smaller volume, a miniature navigation computer system based on new type of floating-point digital signal processor(DSP)——TMS320F28335 is designed to replace similar system on dual-processors. The computing capability of the floating-point unit can satisfy the performance requirements of navigation algorithm. System functions of data collection and communication can be achieved with on-chip six-channel A/D converter, three asynchronous serial interfaces, and dual controller area network (CAN) buses. Data can be saved in a off-chip low-cost nonvolatile large memory, and a DSP array is constructed via the on-chip high speed interface. Simulation results indicate that the system functions of data collection，communication and navigation calculation can be accomplished in one cycle time, and the high-performance navigation computer system is implemented with minimum number of chips.

Transfer Alignment Techniques of Strapdown Inertial Navigation System for Sub-launched Missile

CHENG Ming-wen, LIU Yong-zhi, XU Xian-qiang

2010, 18(5): 367-370. doi: 10.11993/j.issn.1673-1948.2010.05.010

[Abstract](1837) [PDF 340KB](725)

Abstract:
With the development of modern wars, sub-launched missile has played an important role in medium-scale attacks. So fast and accurate transfer alignment of strapdown inertial navigation system(SINS) on moving submarine becomes a crucial technique. We investigate the misalignment angle and the uncertain angle between master inertial navigation system(MINS) and strapdown inertial navigation system（SINS） making use of H∞ filter method, then model and simulate the design of the transfer alignment based on angular rate and acceleration matching. Simulation results show that with our method the higher precision and shorter response time for the transfer alignment of sub-launched missile are obtained without needing submarine for any other maneuvering.

Framework of Integrated Development Environment for Torpedo Guidance System

WU Xu-Guang, NIU Yun, WANG Hao, WU Xiang

2010, 18(5): 367-370. doi: 10.11993/j.issn.1673-1948.2010.05.011

[Abstract](1537) [PDF 189KB](685)

Abstract:
To meet the requirements of software development for torpedo guidance systems (TGS), the framework of the embedded software integrated development environment (IDE) for TGS is studied. The proposed solutions can integrate the design, debug and experiment tasks of TGS into an IDE based on Eclipse. By designing Eclipse plug-ins, the IDE can integrate the functional components in TGS software and provide a uniform and friendly graphical user interface (GUI) for system designers. The advantages of the designed IDE include shorter design period, lower design cost, and openness. The components for the next generation of TGS can also be integrated into the proposed IDE.

Numerical Investigation to Gas Turbine Performance of Underwater Vehicle

YI Jin-bao, ZHAO Wei-bing, SHI Hai-chao

2010, 18(5): 376-380. doi: 10.11993/j.issn.1673-1948.2010.05.012

[Abstract](1673) [PDF 275KB](749)

Abstract:
A three-dimensional, viscous, steady computational fluid dynamics(CFD) analysis is performed for investigating gas turbine flow field and performance of underwater vehicle by solving RANS-Navier-Stocks equations and RNG- turbulence model. The flow detail and losses of the turbine are studied in designing and off-designing conditions. The effect factor on turbine efficiency is analyzed. The results show that the flow characteristics of nozzle are independent of turbine blade flow. When pressure ratio is less than a critical value, the performance of turbine degrades rapidly as pressure ratio decreases. The turbine efficiency gets the maximum at another critical pressure ratio, and descends fast with pressure ratio decreasing when pressure ratio is less than the critical value.The turbine efficiency also descends as rotational speed decreases.

Application and Simulation of VSS-DTC Control on Torpedo Electric Driving System

GUO Zhi-rong, CHENG Wen-xin, WANG Ding

2010, 18(5): 381-384. doi: 10.11993/j.issn.1673-1948.2010.05.013

[Abstract](1584) [PDF 188KB](760)

Abstract:
Aiming at the issues of structure complexity and limitations of motor speed and capacity in torpedo DC driving system, an electric driving system with permanent magnetic synchronous motor(PMSM) is proposed by adopting direct torque control(DTC). To solve those problems associating with conventional DTC of PMSM, such as high flux, large torque ripple, and variable switching frequency, a new variable structure sliding mode (VSS) control strategy is introduced. Simulation results show that VSS-DTC method improves the dynamic and static operational performances of the torpedo DC driving system.

Discussion on Rotational Speed Fluctuation of External Shaft on Thermal Power System for Underwater Vehicle

ZHAO Jin-hong, WANG Qin-juan, HUANG Feng-jun, ZOU Guang-can

2010, 18(5): 385-388. doi: 10.11993/j.issn.1673-1948.2010.05.014

[Abstract](1655) [PDF 167KB](724)

Abstract:
The abnormal speed fluctuation of the external shaft was found in a thermal power system test. We systematically analyze the working properties of engine，electric generator, vehicle shell and rudder actuator, which are closely connected with the external shaft of engine, and establish a mathematic model to support the analysis and estimation. The conclusion is drawn that the rotational speed fluctuation of the engine external shaft is caused by the change of the electrical power load on electric devices, and this change of the electrical power load also disturb the roll control circuit. The improper response to the disturbance causes frequent movement of the differential rudder actuator, which makes the rotational speed of engine external can not get complete recovery in the end.

Numerical Simulation of Flow Field in Firing Valve for Underwater Launch System Based on Fluent/Simulink

ZHANG Xiao-fang, WANG Shu-zong

2010, 18(5): 389-392. doi: 10.11993/j.issn.1673-1948.2010.05.015

[Abstract](1572) [PDF 234KB](1297)

Abstract:
The firing valve is the important device in underwater torpedo launch system. The mass flow rate of gas through the valve determines the interior trajectory of torpedo and transient characteristic of the launch system. A new simulation method is proposed in this paper, which combines three-dimensional compressible flow equations for governing the gas flow in the valve and one-dimensional ordinary differential equations for governing the thermodynamics of air bottle and cylinder. Simulation is performed using the co-simulation method which couples the commercially available computational fluid dynamics(CFD) software FLUENT and one-dimensional dynamic simulation software Simulink together. The mass flow rate values computed by the CFD simulation coincide well with the analytical ones, which validates the simulation method. The results may facilitate the further research of the flow-induced vibration and aerodynamic noise of the launch system.

Multispeed Guidance Method for Wire-guided Torpedo

ZHANG Chi

2010, 18(5): 393-396. doi: 10.11993/j.issn.1673-1948.2010.05.016

[Abstract](1904) [PDF 211KB](716)

Abstract:
According to the technical requirement and tactical condition for guiding and controlling a wire-guided torpedo, we analyze the problem in guiding a wire-guided torpedo at low velocity, and present a new guidance method named “multispeed guidance method”. Simulation results show that the method can extend the available shooting area of the torpedo launch platform, and increase the ship′s maximum speed which the torpedo can attack. And we propose a method for implementing guidance and control of a wire-guided torpedo with different speeds. This study may be of significance for improving the guidance and control scheme of submarine torpedo and enhancing the effectiveness of the multispeed torpedo.

Simulation on Firing Parameters Optimization of Parallel Salvo for Shipborne Acoustic Homing Torpedo

LIU Xin, TANG Xian-ping, CHU Lei, QIU Qi-ji

2010, 18(5): 397-400. doi: 10.11993/j.issn.1673-1948.2010.05.017

[Abstract](1735) [PDF 194KB](768)

Abstract:
In order to study the solution of the salvo parameters for shipborne acoustic homing torpedo, we set up a model to calculate salvo parameters according to the process of torpedo parallel course salvo. Simulations are conducted with emphasis on the optimizations of spread dispersion angle and spread coefficient for the different ranges of torpedo. Simulation result shows that the torpedo hit probability is affected significantly by torpedo firing parameters of parallel salvo.

2010 Vol. 18, No. 5

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