水下无人系统学报

A Reliability Evaluation Method for Underwater Vehicle Based on Running Time

ZHOU Chun-ming, Lü Hong

2012, 20(4): 241-244. doi: 10.11993/j.issn.1673-1948.2012.04.001

[Abstract](1332) [PDF 217KB](603)

Abstract:
To improve the existing evaluation method of running working reliability for an underwater vehicle, an equivalent evaluation method of running working reliability for an underwater vehicle is proposed by combining binomial distribution and exponential distribution according to the data of running time and success/failure data obtained from sea trial. The pro-posed method can solve the problem of lack of given time in the existing evaluation method, improve test data utilization, evaluate the running working reliability of an underwater vehicle more objectively and accurately.

Fuzzy Comprehensive Evaluation Method for Torpedo Comprehensive Performance

WEI Jian-long, TIAN Zheng, ZHAO Wei, LI Fu-xiao, YU Wei, LI Jie

2012, 20(4): 245-250. doi: 10.11993/j.issn.1673-1948.2012.04.002

[Abstract](1018) [PDF 351KB](527)

Abstract:
To effectively analyze and deal with fuzzy information of torpedo comprehensive performance, we present a fuzzy comprehensive evaluation method by using fuzzy theory, introduce its implementation detail, solve the weight by using the improved analytic hierarchy process (IAHP), analyze the evaluation result via an example, and discuss the proposed method. The results show that the proposed method is feasible and reasonable.

Comparison and Analysis of Two Calculation Methods of Space Time Covariance Matrix for Reverberation

Lü Wei, WANG Zhi-jie, LI Jian-chen, WANG Ming-zhou, HU Qiao

2012, 20(4): 251-255. doi: 10.11993/j.issn.1673-1948.2012.04.003

[Abstract](1015) [PDF 477KB](617)

Abstract:
Calculation of covariance matrix is a basis for space time adaptive processing(STAP). Two methods for cal-culating reverberation covariance matrix, the steering vector synthesis method adapting to theoretical analysis and the direct array data domain method adapting to engineering, are discussed in this paper. The principles and applications of the two methods are analyzed, and their calculation differences in the form, eigenvalue, power spectrum and improve-ment factor of reverberation covariance matrix are compared. Simulation results illustrate that the two methods are ob-viously different, and the direct array data domain method lays the more exact theoretical foundation for its application to STAP.

Application of Finite State Machine to Program Design of Torpedo Search Strategy

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

2012, 20(4): 256-260. doi: 10.11993/j.issn.1673-1948.2012.04.004

[Abstract](899) [PDF 139KB](523)

Abstract:
A design scheme of torpedo search strategy program based on finite state machine is presented to improve the design efficiency and readability of torpedo search strategy program, and to facilitate the modification of logic and de-bugging. The definition standard and model of homing state, event, and activity are established by analyzing the torpedo homing logic relations at such stages as searching, pursuit and identification of target. The state transition diagram of homing logic and the implementation of homing program are introduced based on the finite state machine theory. The model and design scheme are validated by simulation, and the results show that the program operation on state machine is stable; the debugging and pursuit are easy; especially, adding state, altering logic and debugging program become convenient.

Passive Detection Model for Underwater High-speed Small Targets with Application

HU Qiao, HAO Bao-an, YI Hong, YANG Yun-chuan

2012, 20(4): 261-266. doi: 10.11993/j.issn.1673-1948.2012.04.005

[Abstract](1098) [PDF 348KB](818)

Abstract:
For accurately detecting underwater high-speed small targets, a novel passive detection model is proposed based on the three-dimensional hyper beam forming (3D-HBF)method with flexible control of beam width and side lobe, and the fuzzy support vector data description (FSVDD) detector with excellent target detection capability. And its im-plementation method is also discussed. In the scheme, 3D-HBF is carried out to obtain the beam response vectors (BSV) from original underwater acoustic signals, and then the BSV are input to the FSVDD detector to detect and orient the underwater targets intelligently. The application of the proposed model to target detection of underwater high-speed small targets in sea trial demonstrates its better detection performance and higher detection success rate and localization accuracy, compared with the conventional beam forming based detection method.

A Digital Automatic Gain Control Method for Acoustic Receiver

MA Ding-kun, ZHANG Xiao-min, LUO Jian

2012, 20(4): 267-270. doi: 10.11993/j.issn.1673-1948.2012.04.006

[Abstract](1141) [PDF 339KB](810)

Abstract:
To suppress the effects of signal power, distance, and medium attenuation in propagation on the fuze action of underwater weapon, automatic gain control(AGC) is necessary for narrowing the dynamic scope of signal amplitude. We proposed an AGC method based on the number of signal amplitude over threshold, and analyze the principle of signal amplitude detection in this paper. To eliminate the influence of receiver noise on AGC errors, we presented a way to optimize the threshold selection. Application of our method to an underwater acoustic receiver system demonstrates its high control precision and anti-interference performance.

Global Path Planning for AUV Based on Sparse A* Search Algorithm

CHEN Shi, LIU Chun-wu, HUANG Zhi-ping, CAI Guo-shan

2012, 20(4): 271-275. doi: 10.11993/j.issn.1673-1948.2012.04.007

[Abstract](2087) [PDF 204KB](767)

Abstract:
Classical autonomous underwater vehicle (AUV) path planning algorithms, such as artificial potential field method and graph search algorithm, often result in the problems of easily converging on local optimum and low calcula-tion speed. To solve the problems, a new method for distributing random points is proposed based on the sparse A* search algorithm for constructing search space, where a random function is used to evenly distribute enough search nodes in the path planning area. This method can obviously reduce the calculation work and increase the search effi-ciency. After the original path is deduced, an intervisibility test is conducted to reduce the path turning points and get an optimal path. Simulation result shows that the proposed method is feasible and valid, and it features better global opti-mization and higher calculation speed.

Optimal Path Planning Method for Underwater Terrain-aided Navigation

SHEN Jian, LI Heng, ZHANG Jing-yuan

2012, 20(4): 276-280. doi: 10.11993/j.issn.1673-1948.2012.04.008

[Abstract](1219) [PDF 265KB](559)

Abstract:
To ensure that underwater terrain-aided navigation system can obtain enough terrain information in path planning, we propose an optimal path planning method considering comprehensively navigation tasks and terrain information. Firstly, we establish a distribution model of underwater terrain entropy information, then search optimum globally in matching area via the particle swarm optimization algorithm to obtain optimal path according with requirements by taking terrain information and path length as optimization target and considering the restraints of obstacle and maneuverability of an underwater vehicle. Finally, we simulate the matching process along the path by using the particle filter terrain matching method. Simulation re-sults show that the proposed method is feasible, and can give optimal path with enough terrain characteristics.

An Improved Navigation Positioning Method for Underwater Moving Target at Long Range

DU Zhao-ping, LIU Bai-feng, ZHAO Ye

2012, 20(4): 281-284. doi: 10.11993/j.issn.1673-1948.2012.04.009

[Abstract](999) [PDF 222KB](540)

Abstract:
Two conventional positioning methods for an underwater moving target, i.e. ship-borne hydrophone ar-ray-acoustic beacon tracking positioning method and ship-towed hydrophone array-acoustic beacon tracking positioning method, are of low tracking positioning accuracy, and of difficulty in implementation and equipment maintenance. So we presented an integrated guidance technology by equipping underwater target with optical fibre gyro and adopting dif-ferential global positioning system(DGPS) to measure and record in real time the attitude, velocity and position coordi-nates of an underwater moving target. The position coordinate data of the target are converted to synchronous underwa-ter acoustic multi-frequency and multi-pulse time-delay encoded signal for transmission, and the encoded signal is measured by ship-towed hydrophones and real-timely resolved by ship-borne base station, thus the measuring and con-trol ship can be guided to accomplish the tasks of tracking, positioning, and monitoring an underwater target at long range in real time. The sea trial result demonstrates the effectiveness of the proposed positioning technology.

Numerical Simulation of Torpedo Turbine Flow Passage Field and Performance Using ANSYS CFX

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

2012, 20(4): 285-289. doi: 10.11993/j.issn.1673-1948.2012.04.010

[Abstract](1412) [PDF 398KB](941)

Abstract:
Torpedo turbine flow passage field and performance are simulated by using computational fluid dynam-ics(CFD) software ANSYS CFX, and the general steps of designing torpedo gas turbine flow passage with CFD are in-troduced in order to predict the gas turbine flow passage field and performance and to promote application of CFD tech-nique to design of torpedo turbines. The results show that the predicted turbine efficiency agrees well with the test data. This study may offer a reference for development of new torpedo turbines.

Non-position-sensor Control for Counter-rotating PMSM Based on High Frequency Voltage Pulse Injection

XU Hai-zhu, XIE Shun-yi, CUI Wei-kai, WANG Song-lin

2012, 20(4): 290-294. doi: 10.11993/j.issn.1673-1948.2012.04.011

[Abstract](936) [PDF 303KB](1872)

Abstract:
To simplify the configuration of counter-rotating permanent magnet synchronous motor(PMSM) and improve its working performance, a non-position-sensor control technique for counter-rotating PMSM is studied. A mathematic model for counter-rotating PMSM is deduced according to the character of surface-mounted PMSM. A speed estimation method is proposed based on high frequency voltage pulse injection according to equal speed of inner and outer rotors in steady state. Moreover, a speed tracking observer is designed, and both simulation model and non-position-sensor con-trol system of counter-rotating PMSM are established. Simulation results agree well with theoretical analysis, which verifies that the proposed strategy is competent for non-position-sensor control of surface-mounted PMSM in full speed scope with accurate tracking performance, high robustness and quick response.

A Winding Eddy Current Loss Suppression Method for Power-type Axial Flux Permanent Magnet Machine with Coreless-stator

WANG Xiao-lei

2012, 20(4): 295-300. doi: 10.11993/j.issn.1673-1948.2012.04.012

[Abstract](1516) [PDF 386KB](690)

Abstract:
The power-type axial flux permanent magnet(AFPM) brushless machine without stator cores is used for pro-pelling device of underwater vehicle. However, high eddy current loss is induced in its stator windings because the windings are directly exposed to the time-varying air gap magnetic field, which influences the performance of the ma-chine. In this paper, the eddy current loss calculating formulas for two winding conductor sizes are deduced, and a solu-tion to reduce the eddy current loss in coreless-stator windings is proposed by substituting thin inter-twist wire for the flat conductor with rectangular cross-section. A two-dimensional finite element model of equivalent linear motor is con-structed to analyze and calculate the eddy current loss. Eddy current test of a 11 kW AFPM machine with coreless-stator verifies the validity and feasibility of the proposed theory and method．

Analysis of Operational Efficiency for Airdropped Torpedo on Anti-submarine Patrol Aircraft

XU Yi-cheng, SUN Ming-tai, LI Ju-wei

2012, 20(4): 301-305. doi: 10.11993/j.issn.1673-1948.2012.04.013

[Abstract](1569) [PDF 338KB](543)

Abstract:
This paper discusses the main influencing factors on attacking submarine operation by an airdropped tor-pedo from an anti-submarine patrol aircraft, and analyzes the target location dispersion error and the water entry dis-persion law of an airdropped torpedo. According to the working principle of a homing torpedo, a target detection model and a hitting judgment model are established, and the fundamental method for an anti-submarine patrol aircraft to attack submarine with an airdropped torpedo and the parameter solution method of dropping torpedo are introduced. and the relations between hit probability and the influencing factors are analyzed by using Monte Carlo simulation method.

An Idea of Designing a Submarine Threat Evaluation Model for Surface Vessels

LIN Zong-xiang, SUN Yong-kan, LI Xue-fei

2012, 20(4): 306-309. doi: 10.11993/j.issn.1673-1948.2012.04.014

[Abstract](1224) [PDF 136KB](499)

Abstract:
To improve decision-making ability of a surface vessel against a submarine, so as to decrease the counterat-tack possibility of the submarine in the process of antisubmarine warfare, the necessity of evaluation of submarine threat against surface vessel is analyzed, and the purpose and principle of the threat evaluation are discussed. An idea of de-signing a submarine threat evaluation model for surface vessels is put forward. The steps and architecture of the threat evaluation model are described in detail, and two main submodels, i.e. the attack intention inference model and the at-tack ability evaluation model, are discussed intensively. The idea may offer a reference for realizing submarine threat evaluation for surface vessels.

Preliminary Discussion on Generation and Control of Underwater Weapon Launching Noise

ZHANG Zhen-shang, CHENG Guang-tao

2012, 20(4): 310-313. doi: 10.11993/j.issn.1673-1948.2012.04.015

[Abstract](1339) [PDF 192KB](618)

Abstract:
Launching underwater weapon will generate impact vibration noise to weaken underwater acoustic stealth performance of the launching platform and reduce its operational effectiveness. The generation and propagation of the launching noise are analyzed, and the generation mechanism of the underwater noise as well as the main research trend of noise reduction are discussed. The generation of jet noise near launch tube nozzle is intensively analyzed, and some suggestions to reduce launching noise are offered for low noise design of underwater weapon launchers.

An Improved Manipulation Scheme for Emergency Baffle in Torpedo Launcher

HUANG Bo, ZHANG Yong, WEI Yong, ZHANG Xiao-fang

2012, 20(4): 314-316. doi: 10.11993/j.issn.1673-1948.2012.04.016

[Abstract](1483) [PDF 135KB](563)

Abstract:
The non-bubble torpedo launcher has a crucial effect on covert attack of submarine. According to the principle of non-bubble torpedo launcher for submarine, the actual working status of emergency baffle under different manipula-tion mode is analyzed, and the distinct deficiency of the existing electrohydraulic driving mode at large depth is found out. Thus, an improved manipulation scheme for emergency baffle is proposed, in which the time-fixed relay in the electrohydraulic manipulation system is replaced with a self-adjusting controller. Moreover, base on the requirement of practical technique and tactics and the characteristic of submarine equipment, a handy self-adjusting controller is de-signed, and some involved pivotal problems are explained.

Air Pressure Variation in Submarine Cabin after Launching Weapon

JIANG Bing-bing, LIU Yong-zhi, PANG Hong-zhao

2012, 20(4): 317-320. doi: 10.11993/j.issn.1673-1948.2012.04.017

[Abstract](1293) [PDF 136KB](535)

Abstract:
To understand the influence of air pressure variation in submarine cabin on human health after launching weapon, a formula for calculating air pressure variation in submarine cabin is derived according to the basic principle of submarine weapon launcher, the air state formula and the air pressure transmission theory. The feature and rule of the air pressure variation after launching weapon is investigated via simulation, and the harmful influence of air pressure varia-tion on human health is analyzed. In addition, a suggestion about air pressure control is offered on the basis of physiol-ogy and human protection theory.

2012 Vol. 20, No. 4

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