水下无人系统学报

Trajectory Organization and Propulsion Mode of Anti-torpedo Torpedo Based on double Attack Mode

LUO Kai, LI Dai-jin, DANG Jian-jun, WANG Yu-cai

2013, 21(5): 321-325. doi: 10.11993/j.issn.1673-1948.2013.05.001

[Abstract](1014) [PDF 1941KB](429)

Abstract:
The operational capacity of hard killing anti-torpedo weaponry, such as anti-torpedo torpedo, is essential for heavyweight warships. The hit probability of an anti-torpedo torpedo is low since it attacks from the fore-hemisphere of an incoming torpedo. This paper proposes a double attack mode including attacking and chasing, and provides trajectory organization and theoretical analysis method. This double attack mode can pursuit the target in the case of attack failure and improve the intercept hit probability significantly. Through theoretical trajectory calculation of the double attack mode, the theoretical operational performance indexes of an anti-torpedo torpedo with various propulsion modes are obtained via comparative analysis of the rocket jet propulsion, conventional turbine engine propulsion, turbine pump water jet propulsion and other propulsion modes. The allowable launch distance is more than 20 cab in turbine pump propulsion mode, which is 2.3 times of the allowable launch distance in rocket propulsion mode. By considering gener-ality, reliability, developmental potential and other factors, the turbine pump is the best power propulsion mode for an anti-torpedo torpedo.

Simulation on Impact Response to Water Entry of Underwater Acoustic Countermeasure Bullets

BANG Zhi-hui, LIU Rong-zhong, GUO Rui, ZHANG Jun

2013, 21(5): 326-331. doi: 10.11993/j.issn.1673-1948.2013.05.002

[Abstract](1228) [PDF 3852KB](419)

Abstract:
The water entry impact of underwater acoustic countermeasure bullets has a significant influence on the reli-ability of the bullet. A dynamic simulation model of water entry impact is established by arbitrary Lagrange-Euler(ALE) algorithm. The feasibility of the simulation is verified by an experiment of a spherical bullet entering into water. Fur-thermore, numerical simulations of water entry impact of underwater acoustic countermeasure bullets are conducted in different conditions to analyze the cavitation, the bullet motion and the shock response of shell, which are caused by the water entry impact of the bullet. The results show that the cavitation is significantly influenced by the shape of bullets; the bullet speed exhibits high attenuation characteristic at the early stage of water entry; with the water entry angle in-creasing, the stability of bullet entering into water enhances, but the axial impact resistance gets larger; compared to the aluminum shell, buffering effect of the plastic shell on the water entry impact of the bullet is larger.

Application of Survival Analysis Theory to Reliability Assessment of Torpedo Storage

XIE Yong, YUAN Bing-cheng, XIE Hui

2013, 21(5): 332-336. doi: 10.11993/j.issn.1673-1948.2013.05.003

[Abstract](1496) [PDF 2066KB](528)

Abstract:
In the case of storage failure time data having the censoring characteristic, it is of significance to scientifically and rationally assess torpedo storage reliability. In this study, on the basis of the censored data of torpedo storage time, the storage reliability of the torpedoes in a batch is assessed respectively by using the turnbull estimation method and the maximum likelihood estimation method in survival analysis theory, and the corresponding calculation program is coded by the software MATLAB. Calculation results of an example show that the survival analysis theory is effective for as-sessment of torpedo storage reliability in the case of storage failure time data censoring, and can obtain more reasonable assessment.

Calculation of Additional Turbulent Force by Slicing Method for Underwater Unpowered Vehicle under Layered Ocean Current

QIU Hai-qiang, YUAN Xu-long, WANG Ya-dong, LIU Chuan-long

2013, 21(5): 337-341. doi: 10.11993/j.issn.1673-1948.2013.05.004

[Abstract](909) [PDF 1977KB](385)

Abstract:
Conventional additional turbulent force calculation method based on constant ocean current velocity introduces large error in the trajectory calculation of an underwater unpowered vehicle due to complexity of ocean current, which influences the vehicle attitude of water outlet. This paper calculates the additional turbulent forces of the vehicle by using the slicing method based on the non-dimensional hydrodynamic coefficient obtained with CFD method, and compares the forces with the ones from conventional method under even ocean current and layered ocean current. Conclusions are drawn that the results obtained with both conventional and slicing methods are consistent with each other under even ocean current, while the slicing method can achieve more accurate result under layered ocean current by selecting proper slicing number.

Numerical Simulation Method of Correlation Noise for Vector Hydrophone

WANG Xu-hu, CHEN Jian-feng, AN Qin-li

2013, 21(5): 342-346. doi: 10.11993/j.issn.1673-1948.2013.05.005

[Abstract](1483) [PDF 2105KB](426)

Abstract:
The covariance matrix of vector hydrophone array output noise is necessary in the array′s design, performance analysis, and simulation of signal processing system. We analyze the output correlation of the vector hydrophone in isotropic noise field and obtain the general formulas for auto-and cross-correlation between two vector hydrophones. With analysis of the probability, a simple method for numerically simulating isotropic noise field is proposed. Numerical simulation results coincide with the theoretical ones, which indicates the proposed method is effective and can generate accurate numerical noise for optimization design of vector hydrophone array and simulation analysis of its signal pro- cessing system.

A Denoising Algorithm for Underwater Acrostic Signal Based on Blind Source Separation and Adaptive Filter

LIU Wei, TENG Wei, LUO Song

2013, 21(5): 347-350. doi: 10.11993/j.issn.1673-1948.2013.05.006

[Abstract](789) [PDF 1661KB](573)

Abstract:
In the application of underwater small aperture array direction finding system, the quality of received con-tinuous wave(CW) signal directly relates to the direction finding error. Due to the influences of multipath effect, fluc-tuation of signal, and underwater background noise, the actual signal detected is usually in low signal to noise ratio (SNR), and the phase estimation results are significantly discrete. According to the characteristics of the underwater CW signal and background noise, a denoising algorithm based on the combination of blind source separation and adaptive filter is proposed in this paper to improve SNR by denoising of received CW waveform. Simulation and lake trial show that the proposed algorithm gains a higher precision than that of the azimuth estimation method with direct application of signal.

UKF-Based Algorithm for MEMS/GPS Integrated Navigation System

LIU Ming-yong, GUO Yong, ZHANG Li-chuan, GAO Pei-lin

2013, 21(5): 351-354. doi: 10.11993/j.issn.1673-1948.2013.05.007

[Abstract](885) [PDF 1895KB](420)

Abstract:
To solve the problems of low navigation accuracy, slow convergence rate and unstable filtering accuracy caused by the strong nonlinearity of the extended Kalman filter(EKF) in micro electro mechanical system/global posi-tioning system(MEMS/GPS) integrated navigation system, an unscented Kalman filter(UKF) is proposed for the MEMS/GPS integrated navigation system. The UKF avoids the heavy derivation in EKF. Simulation results show that the two filtering methods: the error convergence rate of UKF integrated navigation system is faster, the accuracy is higher than the EKF. Comparison between the two algorithms shows that MEMS/GPS integrated navigation system with UKF achieves faster error convergence rate, higher navigation accuracy and enhanced navigation performance.

An Algorithm of Multi-AUVs Cooperative Location Considering Clock Synchronization

ZHANG Fu-bin, ZHANG Xiao-long, MA Peng

2013, 21(5): 355-359. doi: 10.11993/j.issn.1673-1948.2013.05.008

[Abstract](1291) [PDF 2022KB](411)

Abstract:
In the multi-AUVs cooperative navigation system, the leader AUVs are equipped with high-precision navigation and location equipments, the follower AUVs are equipped with low-precision navigation equipments, the leader AUVs and the follower AUVs are all equipped with underwater acoustic modem, and the follower AUVs use the broadcast information from the leader AUVs to obtain the distance to the leader AUVs. This paper aims at the clock asynchrony between the leader and follower AUVs to establish a relative offset model and a relative drift model of AUV clock. By taking the clock offset of a follower AUVs as unknown variable, a multi-AUVs cooperative location algorithm considering clock synchronization is proposed. Simulation results show that the algorithm can greatly improve the location accuracy of the follower AUVs and estimate the clock error of the follower AUVs at any time, thus enhance the performance of the multi-AUVs cooperative navigation system effectively.

Analysis of Temperature Field of Polymer Lithium-ion Battery under Discharge of High-ratio-current

HAO Wen-guang, WANG Jian-ping, WANG Zhi-qiang, TENG Xiao-dong, ZHAO Zi-qiang

2013, 21(5): 360-363. doi: 10.11993/j.issn.1673-1948.2013.05.009

[Abstract](895) [PDF 1961KB](410)

Abstract:
Polymer lithium-ion battery produces large amount of heat under discharge of high-ratio-current to influence the function and safety of a battery. We establish three models of the battery and calculate their temperature fields by using the software ANSYS under discharge of high-ratio-current. The three models are established in the conditions of isotropic thermal conductivity without considering the sizes of positive and negative electrodes, of anisotropic thermal conductivity without considering the sizes of positive and negative electrodes, and of anisotropic thermal conductivity considering the sizes of positive and negative electrodes, respectively. Conclusions are drawn that the sizes of positive and negative electrodes of a battery have great influence on the distribution of temperature field; the errors in the as-sumption of isotropic thermal conductivity are larger than the ones in the assumption of anisotropic thermal conductivity. Therefore, analysis of the temperature fields of polymer lithium-ion battery must comprehensively consider the sizes of positive and negative electrodes and the anisotropy of thermal conductivity.

Numerical Simulation on Flow Characteristic in Labyrinth Seal Passage

GUO Zhao-yuan, ZHANG Jia-he, WAN Rong-hua, JIA Rui, YANG Yan

2013, 21(5): 364-368. doi: 10.11993/j.issn.1673-1948.2013.05.010

[Abstract](1210) [PDF 2073KB](393)

Abstract:
To investigate leakage characteristic of labyrinth seal of steam turbine for engineering design, the flow fields in straight and stepped labyrinth seal passages are numerically simulated by computational fluid dynamics(CFD) method in different conditions and structural sizes and shapes. Subsequently, the flow characteristic in labyrinth seal is analyzed in detail. Simulation results show that the leakage can be effectively reduced by decreasing the pressure ratio, the clearance width, or the angle between axis and cavity edge, or by increasing the number of throttles, but the leakage is insensitive to the speed of rotor.

Analysis on Meshing Efficiency of Straight Conjugate Internal Gear Pair

WANG Zheng-li, ZHANG Zhen-shan, LIANG Wei-ge, ZHANG Fang-fang

2013, 21(5): 369-374. doi: 10.11993/j.issn.1673-1948.2013.05.011

[Abstract](925) [PDF 2337KB](448)

Abstract:
To improve the performance of thermal power as a whole for an underwater vehicle, the meshing efficiency of straight conjugate internal gear pair, which substitute for external gear pair of sea water pump, fuel pump and lubricating oil pump for an underwater vehicle, is investigated, the meshing characteristics of straight conjugate internal gear pair are analyzed on the basis of tangent polar coordinate, and a meshing efficiency function is derived based on the instantane-ous efficiency. Moreover, a formula for calculating the average meshing efficiency(short for meshing efficiency) is ob-tained through integrating in the meshing interval, and the influence of gear deformation on meshing quality is analyzed. Taking the gear pair in NBX3 pump for example, the curves of friction coefficient and gear ratio versus meshing effi-ciency are simulated, and the following conclusions are drawn: 1) tangent polar coordinate is feasible and convenient for analyzing the meshing characteristics of the internal gear pair; 2) meshing efficiency decreases with the increase in fric-tion coefficient, and the decreasing rate of meshing efficiency accelerates with increasing friction coefficient; 3) meshing efficiency decreases with the increase in gear ratio, and the straight conjugate internal gear pair gets higher meshing efficiency than involute internal gear pair.

Simulation of Acoustic Scattering Field of Underwater Targets Based on Approximate Kirchhoff Formula

XIONG Hong-jin, YUAN Bing-cheng, ZHAN Hao-ke, LUO Yin-bo

2013, 21(5): 375-377. doi: 10.11993/j.issn.1673-1948.2013.05.012

[Abstract](933) [PDF 1477KB](536)

Abstract:
Certain assumptions are taken into the classical Kirchhoff formula to obtain an approximate Kirchhoff for-mula for monostatic array, which is used to solve the acoustic scattering field of spherical targets. As a result, the curve of the acoustic scattering field of spherical targets is achieved by means of MATLAB, and the relations of the acoustic scattering field with the range and incident wave frequency are analyzed. Application indicates that the conclusions drawn from this study are applicable to detection and identification of buried targets underwater.

Countermeasure Method of Multi-torpedo Against Soft Defense Layer of Submarine

SUN Guo-zhen, XIE Zhi-qiang

2013, 21(5): 378-383. doi: 10.11993/j.issn.1673-1948.2013.05.013

[Abstract](863) [PDF 2190KB](406)

Abstract:
Based on the analysis of defense way of submarine weaponry, the soft defense capability of a submarine is discussed in detail, and the soft defense layer composed of anti-torpedo weaponry is analyzed and modeled. Due to a certain ambiguity of target submarine information, a fuzzy set is used to express various parameters of anti-torpedo weaponry, and accurate calculation is performed to get the exact values and a calculation model of damage degree. In the condition of only considering soft defense layer, the methods for computing hit probabilities of single-torpedo, dou-ble-torpedo and multi-torpedo are gained, and the effectiveness of combined operation is analyzed. Simulation results show that with the number of torpedo increasing the survival probability of torpedo through the soft defense layer is increased, and the surviving probability also increases for same type of torpedo with same hit probability.

Generalization and Application of Shooting Models of Submarine-launched Torpedo

LI Ben-chang, LIANG Tao

2013, 21(5): 384-387. doi: 10.11993/j.issn.1673-1948.2013.05.014

[Abstract](921) [PDF 1352KB](440)

Abstract:
This paper transforms the shooting models of submarine-launched torpedoes with various homing modes into a general equation according to the principle of solution encounter by using the method of parameter substitution, and clarifies the physical meanings of the key parameters, such as torpedo′s range, shooting angle, etc., for judging whether shooting occasion or the current situation meet the shooting requirements. The purpose of this study is to fulfill the standardization and modularization of a project, and to help project designers and tactics executants unanimously com-prehend relative conceptions.

Optimization of Speed Adjustment Strategy for Double-speed Acoustic Homing Torpedo

HU Hong-can, ZHOU Ming, LIN Zhong-xiang, KOU Zhu

2013, 21(5): 388-391. doi: 10.11993/j.issn.1673-1948.2013.05.015

[Abstract](814) [PDF 1519KB](488)

Abstract:
Solution of initial shoot parameters depends on the speed adjustment strategy of a multi-speed acoustic hom-ing torpedo. This study is on the premise that the torpedo-target distance as the multi-speed torpedo changes its speed is longer than the torpedo alarm distance of opponent submarine. A speed setting scheme of the double-speed torpedo is obtained for specified situation by analog calculation taking shorter attack time and longer surplus range as objective. Simulation result shows that the speed setting scheme is reasonable and convenient.

Operational Environment Modeling in Distributed Simulation of Torpedo Homing Performance

ZHANG Yong-ping, ZHANG Jing-yuan, YIN Wen-jin

2013, 21(5): 392-396. doi: 10.11993/j.issn.1673-1948.2013.05.016

[Abstract](962) [PDF 1816KB](389)

Abstract:
To reflect real operational environment in distributed simulation of torpedo homing performance, starting from the information interaction analysis of torpedo homing system and outside environment, the mechanism and guid-ing process of detecting targets are analyzed. And the models of complex marine environment and countermeasure are established for distributed simulation of torpedo homing performance with the distributed simulation technology. Simu-lation results show that these models are reasonable and effective for reflecting the real environment where a torpedo homing system works.

Analysis of Operational Requirement for New Type Anti-ship Amphibious Armoured Vehicle

LIU Chun-sheng, FENG Shi-qi, LIU Hou-gang, CHEN Xiao-ping

2013, 21(5): 397-400. doi: 10.11993/j.issn.1673-1948.2013.05.017

[Abstract](981) [PDF 1447KB](433)

Abstract:
Considering the situation in the South China Sea, we suggest that the new type anti-ship amphibious armoured vehicles be employed for amphibious anti-ship and anti-landing combats in defense of islands and reefs, then analyze the operational requirement for the anti-ship amphibious armoured vehicle. According to the weaponry performances on both attack and defense sides, we also analyze the anti-ship operational capability of the new type anti-ship amphibious armoured vehicle.

2013 Vol. 21, No. 5

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