水下无人系统学报

Modeling and Simulation of Dynamic Characteristics of Slide Jump Steering Trajectory for Trans-media UAV

LI Jin-hong, YANG An-qiang, SU Ling-yun

2012, 20(6): 401-406. doi: 10.11993/j.issn.1673-1948.2012.06.001

[Abstract](1085) [PDF 394KB](649)

Abstract:
A trans-media unmanned aerial vehicle (UAV), flying near water surface, cannot obtain steering force by conventional air rudder, which results in difficult steering and poor maneuverability of the UAV. A slide jump steering method of the UAV on water surface and a dynamic model of slide jump steering flying of the UAV are hence proposed in this paper on the basis of the aerodynamics, the classic potential flow theory, and the two-element plane sliding theory. The slide jump steering characteristics of the UAV and the influencing factors are simulated with the model and ana-lyzed in detail. Moreover, some approaches for inhibiting UAV roll are given. Simulation results show that the wa-ter-entry angle and the fixed rudder angle of the UAV impose significant effects on its posture and trajectory pattern in the process of slide jump steering. This study may provide theoretical and calculation foundation for the UAV′s con-ceptual overall design, trajectory planning, flight reliability design and flight control system design.

Modeling and Simulation of Disturbance Motion for Submerged Mooring Platform

LIU Chuan-long, YUAN Xu-long, ZHAHG Yu-wen

2012, 20(6): 407-410. doi: 10.11993/j.issn.1673-1948.2012.06.002

[Abstract](1083) [PDF 327KB](590)

Abstract:
Submerged mooring platform is widely applied to hydrological monitoring devices such as buoy and subsur-face buoy, and to underwater battle platform such as moorage mine. The platform will drift, descend, pitch and yaw, or even perform a complicated cycling motion to influence the initial calibration of the carried devices. In this paper, a typical submerged moorage platform is studied by dynamic modeling and simulation. A three-dimensional equation of motion is established to analyze the balance and disturbed motion of the horizontal submerged platform attached by fork connection. The effects of system parameters and mooring parameters on the stability of disturbed motion are analyzed via simulation, and some methods for improving the stability of the platform are presented.

Corrosion Protection of Aluminum Alloy Shell of Torpedo Fuel Tank in US Navy

LIANG Zhi-jun, LIU Jin, WU Shi-dong, SHAN Zhi-xiong, LI Chun-yu

2012, 20(6): 411-413. doi: 10.11993/j.issn.1673-1948.2012.06.003

[Abstract](1088) [PDF 159KB](884)

Abstract:
The combined corrosion mechanism of the aluminum alloy shell in both fuel and seawater is introduced for torpedo fuel tank in US Navy. The anodic oxidation method and corrosion inhibitor are used for corrosion protection. For the corrosive shell, the advanced laser cladding renovation method is used to prevent deformation and big heat af-fected zone caused by fusion welding. The laser cladding renovation method can improve the quality of repair without weakening the performance of metallic matrix.

A Data Association Method for Torpedo Multiple-Target Tracking

YANG Xiang-feng, YANG Yun-chuan, GUO Lei

2012, 20(6): 414-418. doi: 10.11993/j.issn.1673-1948.2012.06.004

[Abstract](1000) [PDF 288KB](599)

Abstract:
Multiple-target tracking is one of the important aims in torpedo development, while data association is a basic for the multiple-target tracking. The torpedo multiple-target tracking process registers as a time-varying process of moving base. In this paper, the parameters of localization and running attitude from torpedo navigation system, as well as the target information detected by a torpedo, are utilized to achieve spatial registration via coordinate transformation. The sampling time is calculated in real time and same clock to achieve temporal registration. The Doppler velocity and the geodetic coordinates of target are used to construct four-dimensional data association coordinates. Normalized fuzzy Euclidean-distance is taken as an association rules. So a data association method for torpedo multiple-target tracking is proposed. Simulation result shows the validity of the proposed method.

Distribution Feature Extraction and Simulation of Submarine Echo Highlights Based on Target Azimuth Trend

XU Yu, ZHAO Jun, YUAN Bing-cheng

2012, 20(6): 419-423. doi: 10.11993/j.issn.1673-1948.2012.06.005

[Abstract](1048) [PDF 265KB](563)

Abstract:
Due to the feature extraction method of conventional submarine echo highlight calculates only the azimuth on limited peak points to analyze the target highlight feature, and the robustness is poor. This paper proposes a distribution feature extraction method of submarine echo highlights based on target azimuth trend, by mainly using the characteris-tics that the amplitude of target echo signal is larger than that of noise and the sub-echo signals from the same strong highlight signal embody approximate azimuth and distance information, and combining with the technique of dou-ble-channel short-time cross-spectrum. Firstly, the feature of target azimuth trend is obtained with the technique of dou-ble-channel short-time cross-spectrum. Secondly, the sub-echo signal series is classified by mainly using energy decision and the sub-echo signals′ azimuth and distance information, and then the spatial distribution feature of submarine echo highlights is achieved. Simulation results show that the proposed method is more robust than the conventional method. This study may provide a reference for analysis of submarine acoustic characteristics and acoustic countermeasure system.

A Method for Extending Doppler Tolerance of Underwater Spread Spectrum Signal

SU Jian-jun, FENG Xi-an, BAI Xiao-juan, LI Zhi-wei

2012, 20(6): 424-427. doi: 10.11993/j.issn.1673-1948.2012.06.006

[Abstract](1436) [PDF 266KB](620)

Abstract:
Spread spectrum signal is sensitive to Doppler frequency shift, which limits the service property of the spread spectrum signal. This paper proposes a method for echo pre-processing by analyzing the sensitivity of spread spectrum signal to Doppler frequency shift. Zero intermediate frequency I, Q channel signals are obtained through the orthogonal frequency mixing of echo. Then the signals are processed in the echo pre-processing system to obtain two output signals by time-delay processing method. The two output signals are further processed by a matching filter to achieve a combined signal which doesn’t contain Doppler frequency shift and time product. Numerical simulation demonstrates the validity of the proposed method with simplicity and smaller amount of computation.

Performence Analysis on Broadband Transducer with Matching Layer

TIAN Feng-hua, HE Wen-feng, ZHANG Jun

2012, 20(6): 428-431. doi: 10.11993/j.issn.1673-1948.2012.06.007

[Abstract](1357) [PDF 260KB](634)

Abstract:
A broadband transducer with matching layer was designed with finite element method（FEM）and ANSYS software to make modern torpedo adapt complicated environment. The acoustic velocity, density and thickness of the matching layer were adjusted to analyze the acoustic characteristics of the transducer, including syntonic frequency, transmitting voltage response, receiving sensitivity of free field voltage, and receiving transmitting frequency bandwidth, and to optimize its structure. Tank test of the transducer was conducted, and the results agreed well with computation. This study may offer a reference for sonar array design.

A Cooperative Navigation Method of EKF Moving Long Baseline for AUV Based on Pseudo-range Measurements

LIU Ming-yong, HUANG Bo, CAI Ting

2012, 20(6): 432-436. doi: 10.11993/j.issn.1673-1948.2012.06.008

[Abstract](1433) [PDF 240KB](561)

Abstract:
Moving long baseline(MLBL) localization of an autonomous undersea vehicle(AUV) will produce a certain amount of time-delay positioning error due to the slow acoustic signal propagation velocity in water and the movement of AUV itself, which cause differences in time and position in measuring the distances between an AUV and different buoys. In this paper, an extended Kalman filtering(EKF) MLBL time-delay algorithm based on pseudo-range measure-ment is proposed. In this algorithm, the EKF is adopted to reconstruct the measurement equation of the system via pushing-forward the AUV’s position states. So the measurement equation matches with the system measurement in time, and the error from time delay is eliminated. Theoretical analysis and simulation results show that the algorithm can significantly improve the accuracy of navigation and localization.

Underwater Terrain Matching Techniques Based on Combination of PMF and TERCOM Algorithms

LIU Hong, GAO Yong-qi, SHEN Jian

2012, 20(6): 437-442. doi: 10.11993/j.issn.1673-1948.2012.06.009

[Abstract](1489) [PDF 287KB](669)

Abstract:
Aiming at the problems that point-mass filter(PMF) algorithm is of great computation, slow convergence and initial error sensitivity, a combination scheme of terrain contour matching(TERCOM) algorithm and PMF algorithm is proposed. Firstly, the influence of search area resolution on the PMF algorithm is analyzed. Then a combination scheme taking TERCOM for coarse matching and PMF for fine matching is simulated and compared with the other scheme tak-ing PMF for coarse matching and TERCOM for fine matching. The result shows the former scheme behaves better in convergence and positioning accuracy for both rough and flat terrains with a good engineering application.

Discussion about Random Error Analysis of Torpedo Shooting

LI Chang-wen, REN Xing-zhe, WANG Peng

2012, 20(6): 443-448. doi: 10.11993/j.issn.1673-1948.2012.06.010

[Abstract](1228) [PDF 205KB](596)

Abstract:
Through the description of straightforward shooting of a straight running torpedo, the random error and some concepts of hitting problem are studied, and the difference between success probabilities based on true value and ob-served value of target movement element is pointed out. For objective probability, two analytic methods of computing probability are proposed based on the first order or second order approximation of the function of random error vector. According to a theorem about the formulas to compute the mean value, variance and eigenfunction of a common second order function of normal distributed random vector, an analytic method with the second order approximation is given. Results show that the two analytic methods have high precision, and the first order approximation method is better than the second order one in the case of computing the objective hitting probability of torpedo straightforward shooting.

Modeling and Simulation of Airborne Depth Charge for Driving out Submarine

SUN Ming-tai, REN Dong-yan, LI Ju-wei, WANG Yun-xiang

2012, 20(6): 449-453. doi: 10.11993/j.issn.1673-1948.2012.06.011

[Abstract](1442) [PDF 246KB](620)

Abstract:
The underwater blast power model of an airborne depth charge and the resisting shock wave model of a sub-marine hull are employed to compute the safe-radius to the depth charge and the largest effective-radius based on the analysis of driving out submarine principle. A method to ascertain the bomb-dropping aiming point position is proposed according to the bomb-dropping dispersion model and the target location model, namely, the aiming point of bomb-dropping is determined by weighing the probability of accomplishing driving out target mission and the probabil-ity of destroying a submarine. In addition, some examples with different target location conditions of sonobuoy and magnetic anomaly detector are simulated, and the results indicate that better operational effectiveness control can be achieved based on higher precisions of bomb-dropping and underwater target location.

A Virtual Training System for Torpedo Support Based on Petri Net

ZHANG Qi, HUANG Bo, MA Zhi-feng

2012, 20(6): 454-457. doi: 10.11993/j.issn.1673-1948.2012.06.012

[Abstract](1029) [PDF 330KB](629)

Abstract:
A scheme of virtual training system for torpedo support is proposed based on virtual prototype and simulation control technology to satisfy the training requirement of torpedo support. The torpedo support process based on mainte-nance knowledge description Petri net is discussed in detail. The modeling principle of torpedo support process is ob-tained by analyzing support resource, constraint condition and operational process, and then the simulation flow of the support training system is designed. Simulation indicates that Petri net can perfectly solve the restriction problem of resource and work result on operational process in the system.

Modeling and Simulation of Mother Ship Maneuver for Discriminating Port/Starboard of Target

LIN Zong-xiang, SUN Yong-kan, XIONG Zheng-xiang

2012, 20(6): 458-462. doi: 10.11993/j.issn.1673-1948.2012.06.013

[Abstract](788) [PDF 339KB](538)

Abstract:
To understand the turning angle for mother ship to discriminate the port/starboard of a target, the possible false deduction in the reasoning rule of discrimination is analyzed. A detailed model of mother ship maneuver for discrimi-nating port/starboard of a target is established, in which such factors as the maneuvers of mother ship and target, the maneuvering time of mother ship, and so on, are taken into account. Simulation results indicate that a smaller turning angle is needed to discriminate port/starboard of a target when mother ship′s maneuver direction is opposite to the board angle in which target locates, otherwise a larger turning angle is needed. The polynomial expressions of target board angle′s maximum and minimum just after mother ship maneuver are obtained by fitting the simulation data with the software 1stOpt. Subsequently, the reasoning rule for discriminating port/starboard of a target is improved for more re-liable discrimination.

Discuss on Prolonging Service-life for Underwater Weapon Warhead

HUANG Feng-jun, ZHAO Jin-hong, ZHANG Jun-hu

2012, 20(6): 463-466. doi: 10.11993/j.issn.1673-1948.2012.06.014

[Abstract](1239) [PDF 119KB](640)

Abstract:
Aiming at the problems existing in the serving process of underwater weapon warheads, relating to overtime service, safety, waste, destruction, etc, the demand and necessity for studying prolongation techniques of the warhead service-life is described, and the involved issues are pointed out. Construction and improvement of corresponding technology and management systems, as well as methods and ways of prolonging service-life, are discussed. The necessity of studying destruction and recycle of the warheads is demonstrated. Some suggestions are offered about the existing weak links, the issues claiming attention, the work needing to do, and the applicable space.

Design for Safety and Arming Logic in Torpedo Fuze of Electronic Security System

GAN Yu

2012, 20(6): 467-471. doi: 10.11993/j.issn.1673-1948.2012.06.015

[Abstract](1110) [PDF 269KB](606)

Abstract:
Based on the characteristic and identification mode of arming environment excitation, water pressure data of initial trajectory, safe distance data and target information are selected as arming environment excitation, and a safety and arming logic according with the trajectory characteristic of a torpedo is designed to realize good matching of arming environment excitation and safety as well as arming logic, and to ensure the safety of torpedo overall trajectory. The safety and arming logic is analyzed by using the Markov theory, and the calculated safety value is much larger than the criterion in the standard GJB373A for fuze security system, which can satisfy high safety design need for torpedo fuze.

Current and Future Technology for Anti-Torpedo Torpedo in the World

CUI Gui-ping

2012, 20(6): 472-475. doi: 10.11993/j.issn.1673-1948.2012.06.016

[Abstract](1796) [PDF 108KB](1621)

Abstract:
Major significant development stages of foreign anti-torpedo torpedo(ATT) is summarized. Main perform-ances of some developing ATTs in the world are introduced, and the advantages and disadvantages of each ATT’s tech-nical route are analyzed preliminarily. The generality and trend of ATT technology development in the world are dis-cussed in such aspects as high-frequency homing system, acoustic fuze, and omnidirectional heavy-charge blast warhead. In addition, some ATTs, which may be developed in the future, with different purposes and functions, are forecasted.

Application Prospect of Multidisciplinary Design Optimization to Torpedo Engine

LI Bin-mao, YU Shi-jun, QIAN Zhi-bo, CHENG Hong-jie

2012, 20(6): 476-482. doi: 10.11993/j.issn.1673-1948.2012.06.017

[Abstract](1416) [PDF 229KB](650)

Abstract:
Torpedo engine design technologies are introduced with their development. A new method for torpedo engine design based on multidisciplinary design optimization (MDO) is presented, including three phases——parts design, components design, and overall design. The application prospect of MDO to torpedo engine design is discussed with respect to system decomposition, system optimization model establishment, MDO strategy, optimization algorithm, and MDO platform construction.

2012 Vol. 20, No. 6

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