水下无人系统学报

Five-Degree-of-Freedom Dynamic Model for Torpedo-Parachute System

DENG Li-tao, CAO Xiao-juan, MA Xia, YANG Chun-wu

2011, 19(1): 001-5. doi: 10.11993/j.issn.1673-1948.2011.01.001

[Abstract](1821) [PDF 221KB](708)

Abstract:
In the conventional torpedo-parachute system, the effect of parachute is simplified to a force acting on torpedo tail and being along airflow direction, which leads to inaccuracy in numerical analysis of coning motion. According to the fundamental principles of aerodynamics, we establish a five-degree-of-freedom dynamic model of terminal descent of torpedo-parachute system based on the Newton and Kirchhoff formulas by applying the principles and analytical methods of parachute dynamics and multi-body dynamics. Simulation result demonstrates the reliable convergence and stability of the present system. This system may be applied to the engineering design of torpedo-parachute system.

Parametric Design of Cylinder Shell Based on Spreadsheet

SONG Bao-wei, YE Jing, CAO Yong-hui

2011, 19(1): 006-9. doi: 10.11993/j.issn.1673-1948.2011.01.002

[Abstract](1630) [PDF 217KB](686)

Abstract:
To shorten design period of autonomous underwater vehicle (AUV), this paper presents a new approach by taking optimization design of an AUV cylinder shell construction as an example. The UG′s modeling ability and the MATLAB′s scientific computing function are combined effectively by virtue of the spreadsheet, and the 3D model of cylinder shell is updated according to the optimization result. This paper highlights the way of data transmission between MATLAB and UG via spreadsheet. This study shows that the present method can greatly shorten the structure design period, reduce the engineers’ workload, and make it possible to serialize the product structure design.

Parametric Three-Dimensional Modeling for Torpedo Contra-Rotating Propeller Based on UG OPEN / API

HE Hui-jiang, LI Nan

2011, 19(1): 010-13. doi: 10.11993/j.issn.1673-1948.2011.01.003

[Abstract](1454) [PDF 199KB](996)

Abstract:
Optimization design of contra-rotating propeller is an important part in torpedo shape design. This paper pre-sents a parametric three-dimensional modeling method for contra-rotating propeller based on UG’s second deve- lopment tools OPEN/API, and a parametric model of torpedo contra-rotating propeller is hence established. The modeling method can simplify the analysis process of optimization design of contra-rotating propeller.

High Precision Frequency Estimation Method of Torpedo Acoustic Fuse Target Echo

XIE Sheng, CHEN Hang, YU Ping

2011, 19(1): 014-19. doi: 10.11993/j.issn.1673-1948.2011.01.004

[Abstract](1740) [PDF 433KB](816)

Abstract:
The estimation accuracy of Doppler frequency is affected by the body target effect in near field region of submarine and torpedo, therefore a fast and accurate frequency estimation method is presented in this paper to acquire Doppler frequency in submarine target echo. This method is a combined frequency estimation method based on Rife algorithm and Quinn algorithm, making full use of the low computational complexity of Rife algorithm and the good anti-noise performance of Quinn algorithm. Aiming at the problem that Rife algorithm and Quinn algorithm have larger frequency estimation error when signal frequency is close to the discrete frequency of the discrete Fourier transform (DFT), the modified items of the frequency from Rife algorithm and Quinn algorithm are weighed to improve the fre-quency estimation precision. The simulation result shows that the present method has stable frequency estimation per-formance with less computation, and its root mean square error (RMSE) approaches much closer to Cramer- Rao lower bound (CRLB) than the Rife and Quinn algorithms, which can well meet the requirement of torpedo acoustic fuse for predicting burst point accurately.

High Resolution Acoustic Imaging for Torpedo Target Recognition with Sparse Array

FAN Shu-hong, WANG Ying-min, YUE Ling, KANG Wen-yu

2011, 19(1): 020-26. doi: 10.11993/j.issn.1673-1948.2011.01.005

[Abstract](1693) [PDF 425KB](756)

Abstract:
Underwater acoustic imaging and image guidance are the most effective ways to torpedo target recognition and intelligent precision guidance in modern complex underwater acoustic countermeasure of battlefield environment. In order to realize target image recognition and precise image guidance in torpedoes, aiming at torpedo applications, this study presented an acoustic imaging method with high azimuth and range resolutions by means of preformed dense nar-row beams and image signal processing of each narrow beam. A novel high frequency non-uniform sparse array and the beamforming method were put forward to generate dense narrow beams and achieve high azimuth resolution. And the algorithms of high range resolution imaging processing with wideband signal were proposed for each beam further processing and achieving high range resolution. Additionally, a method for target acoustic image optimization based on double thresholds segmentation and fuzzy clustering analysis was developed. Hence, target high resolution acoustic imaging was implemented with lower hardware complexity of the imaging system and convenience. Computer simula-tions and experiments indicate that the acoustic imaging scheme is effective to achieve target acoustic images with high azimuth and range resolutions.

A Signal Detection Method for Ship Laser Wake Homing Torpedo

GUO Hu-sheng, LIU Qi-zhong, CHEN Chen

2011, 19(1): 027-30. doi: 10.11993/j.issn.1673-1948.2011.01.006

[Abstract](1344) [PDF 300KB](716)

Abstract:
In torpedo′s detecting underwater target with laser, the backscattering echo is much stronger than the useful tar-get-reflected signal, which makes signal detection and processing very difficult. Therefore, we present an effective laser wake detection method, in which a new adaptive interference canceling method is employed via recursive least square（RLS）algorithm to eliminate the backscattering echo, and to detect the target signal complex by using dynamic adaptive threshold and other strategies. Experimental result illustrates that the water backscattering echo can be effective eliminated and the target signal can be extracted with the present method with higher convergence and tracing velocities. A laser wake homing torpedo can make use of this method to detect ship laser wake.

A Time Series Modeling and Real Time Filtering Method for FOG Random Noise

HU Jun-wei, LIU Ming-yong, ZHANG Jia-quan

2011, 19(1): 031-34. doi: 10.11993/j.issn.1673-1948.2011.01.007

[Abstract](1264) [PDF 177KB](623)

Abstract:
In order to reduce the random noise of fiber optic gyroscope (FOG), the random noise of FOG is analyzed and modeled by time series analysis method. Based on the established auto regression moving average（ARMA）(2, 1) model, a method that combines modified recursive extended least squares (RELS) algorithm and Sage-Husa adaptive Kalman filter algorithm is proposed to compensate the static output random noise of FOG in real-time. In addition, the standard Kalman filter algorithm is used for comparison. Simulation results show that the proposed method achieves better com-pensation effect and more effective inhibition of the FOG random noise.

A New Nonlinear Variable Structure Guidance Law for Torpedo

DING Hao, YOU Wen-li, TENG Da

2011, 19(1): 035-38. doi: 10.11993/j.issn.1673-1948.2011.01.008

[Abstract](1721) [PDF 261KB](790)

Abstract:
Torpedo′s target pursuit capability highly dependents on the design of high performance guidance law. In this paper, equations for 3D relative motion between torpedo and targets are built by using global coordinates. Variable structure theory is used to design a new torpedo nonlinear guidance law, and the convergence of the variable structure guidance law is validated. Simulation is conducted for target sine maneuver, and the result is compared with that of the H∞ guidance law. The comparison shows that the variable structure guidance law can help torpedo pursue target within shorter time, and the azimuth angle and pitching angle always keep around the initial values. Furthermore, the normal load doesn’t increase with the decrease of the distance between torpedo and target. So, the present guidance law is ef-fective for torpedo pursuit with good robustness.

A Count Assessment Method of Navigation Localization Accuracy Based on Dual Circular Area for AUV

ZHANG Ning, ZHANG Fu-bin, BAO Hong-jie, ZHANG Yong-qing

2011, 19(1): 039-42. doi: 10.11993/j.issn.1673-1948.2011.01.009

[Abstract](1648) [PDF 196KB](734)

Abstract:
Navigation localization accuracy is an important technical index for an autonomous underwater vehicle (AUV). The probability circle assessment method is not easy to make a quick decision when the navigation accuracy is much lower than the accuracy index and the probability circle radius is selected too small, or it is possible to make a wrong decision when the navigation accuracy does not meet the index and the probability circle radius is set too big. To solve this problem, an assessment method using the dual circular area for underwater navigation accuracy is proposed in this paper. By properly adjusting radiuses of the two circular areas based on the principle of risk-sharing between the devel-oper and the user, the proposed method can reduce the impacts of navigation system errors on assessment, and make quick decisions when AUV navigation accuracy is much lower than the navigation index. Simulation results demonstrate the feasibility and effectiveness of the proposed method.

A Storage Reliability Evaluation Method of Lithium Battery Based on Capability Degenerate Data

HUANG yan, SONG Bao-wei, XIE Ya-li

2011, 19(1): 043-47. doi: 10.11993/j.issn.1673-1948.2011.01.010

[Abstract](1585) [PDF 185KB](727)

Abstract:
The high power lithium batteries often display few failures but more energy loss in storage. Their energy pa-rameters and metrical data are indeterminate and incomplete. In order to evaluate the storage reliability of the battery, this paper presents a method, in which a fuzzy membership function is established to estimate the incomplete data of the battery based on normal data. The storage reliability of the battery can be obtained with this method. Comparison of several groups of battery data proved that the method is effective and practical.

Numerical Simulation about Combustion Performance of Choked Combustor of Turbine

QIAO Hong, ZHAO Wei-bing, MA Xiao-li, SHI Hai-chao

2011, 19(1): 048-54. doi: 10.11993/j.issn.1673-1948.2011.01.011

[Abstract](1565) [PDF 558KB](664)

Abstract:
In order to study the form of turbine combustor and verify its performance, a new choked combustor scheme which is suitable for tri-propellant and matches the lower gas inlet pressure of a turbine under low operating condition was proposed. The combustion characteristics of scheme under multi-operating conditions were simulated based on computational combustion dynamics. Simulation results show that the tri-propellant burns completely, the water vapor-izes entirely, the flow field in the combustor is satisfactory, and the front pressure of the nozzle ring meets the require-ment of the turbo-pressure. This new choked combustor with its simulation results may benefit the design of turbine combustors with tri-propellant.

Operational Effectiveness Evaluation for Intelligent Mine Based on Grey Theory

ZHANG Dong, SONG Yu-nong

2011, 19(1): 055-58. doi: 10.11993/j.issn.1673-1948.2011.01.012

[Abstract](1102) [PDF 169KB](596)

Abstract:
Intelligent mine is the major weapon in the future naval blockade. Based on the evaluation system of intelli-gent mine, this paper determines the evaluation index weights by employing the improved weight analysis, and estab-lishes an evaluation model with the improved gray theory. Taking intelligent mine as an example, the operational effec-tiveness is evaluated quantitatively with this model. The results show that the model can make full use of the judgement information from commanders to reflect the actual operational effectiveness correctly. This model may be beneficial to the application of intelligent mine in the future naval blockade.

Two Probability Model of SLMM Hitting Predetermined Obstacle Zone

LENG Xiang-wen, ZHAO Xiao-zhe, ZHANG Xu, ZHU Hong-bo

2011, 19(1): 059-62. doi: 10.11993/j.issn.1673-1948.2011.01.013

[Abstract](1477) [PDF 193KB](663)

Abstract:
Based on the operational specialty of submarine launched mobile mine(SLMM), two general models which describe the probability of SLMM hitting predetermined obstacle zone were established. Two examples were simulated to verify the models. The simulation results of both models concerning regularity, accuracy and adaptability were com-pared. The conclusions may be applied to the analysis of characteristics of SLMM position dispersion and the optimiza-tion of mine obstacle configuration.

Operational Model for Intercepting Uncertain Type of Torpedo with Hovering Depth Charge

YAO Feng-liang, JIA Yue, DING Bei

2011, 19(1): 063-67. doi: 10.11993/j.issn.1673-1948.2011.01.014

[Abstract](1133) [PDF 217KB](746)

Abstract:
How to use hovering depth charge to intercept torpedo is one of the main problems in surface ship torpedo defense. Fuzzy mathematics knowledge is used in this paper for dividing a torpedo warning distance into near, middle, and far fields to establish torpedo warning distance functions and estimate torpedo course and speed. Hence, an opera-tional model for surface ship to intercept uncertain type of torpedo with hovering depth charge is constructed. Simulation via the Monte-Carlo method is performed, and the result shows that intercepting uncertain type of torpedo with hovering depth charge is the most available measure, which can achieve the purpose of completely damaging the torpedo and ensuring the safety of surface ship.

Inner Trajectory Modeling and Simulation of Hydraulic Energy Accumulated Torpedo Launcher

TIAN Bing, WANG Shu-zong, LIAN Yong-qing

2011, 19(1): 068-71. doi: 10.11993/j.issn.1673-1948.2011.01.015

[Abstract](1655) [PDF 199KB](1560)

Abstract:
For its low launching noise and absence of increasing pressure in chamber, the hydraulic energy accumulated torpedo launcher has held navies′ interest around the world. In this paper, to research the inner trajectory characteristic of the launcher, an inner trajectory model for the launching course is built on the basis of the structure and launching theory by proper simplification and hypothesis. Simulation is performed with MATLAB/Simulink, and the result shows the validity of the model. Tactical and technical indexes of the launcher should be considered in determination of its structure parameters and initial energy storage to meet the requirement for inner trajectory characteristic.

An Incoming Torpedo Warning System Based on Ship Early Underwater Defense

LI Wei, WANG Hong-sheng, TIAN De-hai

2011, 19(1): 072-76. doi: 10.11993/j.issn.1673-1948.2011.01.016

[Abstract](1497) [PDF 195KB](855)

Abstract:
According to the requirement of threat information acquisition for ship early underwater defense, this paper analyzes the tactic and technical indexes of incoming torpedo warning system, including the detection range, working band, action space, signal recognition, automation and time continuity, explains the information sources and the signal characteristics extraction of the incoming torpedo warning system in terms of the prior information, initial noise, sail noise, active acoustic homing signal and target signal classification. Furthermore, this paper also discusses the basic principles, design features, and key technologies of the incoming torpedo warning system in the case of passive towed linear cluster-type multi-element array sonar. This study may provide reference for torpedo design optimization under countermeasure condition.

A Test Method of Gas Turbine Performance Analog for Underwater Vehicle

CHEN Gang, SHI Hai-chao, YI Jin-bao, ZHAO Hai-Tao

2011, 19(1): 077-80. doi: 10.11993/j.issn.1673-1948.2011.01.017

[Abstract](1753) [PDF 280KB](763)

Abstract:
Aiming at the shortcomings in power system test, the fundamental principle of gas turbine for underwater vehicle is analyzed. Based on the aerodynamics and the flow field similarity theory, the test principle and method of gas turbine performance analog are discussed, and a test method for verifying design condition is presented through analo-gize the performance of gas turbine under low condition. This study may be regarded as a reference in gas turbine per-formance verification and test facilities development.

2011 Vol. 19, No. 1

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