水下无人系统学报

Dynamic Modeling and Simulation on Flexible Intercepting Net

LEI Jiang-tao, YANG Zhi-dong, KANG Le, LI Hao-yi

2017, 25(1): 007-10. doi: 10.11993/j.issn.1673-1948.2017.01.002

[Abstract](978) [PDF 389KB](392)

Abstract:
For torpedo attack in a certain course area, the flexible intercepting net can achieve good interception effect. In this paper, the net is discretized based on the lumped mass method, and the intercepting net is divided into end nodes and intermediate nodes, which are connected with massless virtual spring. Following the Newton’s second law, the governing equations of the discrete nodes are established, then the dynamic differential equation of the end node, the intermediate node and the floating body is established. The mesh group algorithm and the numerical method for solving the dynamic equation of the floating structure net are given for simplified solution to net deformation. The rationality of the model is verified by dynamic simulation. This research may provide a theoretical reference for intercepting torpedo with flexible intercepting net.

Filter Design Based on EDA Software

ZHOU Guo-ming, WANG Jian-ping

2017, 25(1): 011-17. doi: 10.11993/j.issn.1673-1948.2017.01.003

[Abstract](737) [PDF 1660KB](387)

Abstract:
In the torpedo communication and control systems, filters are used to deal with analog signals. Conventional design of the filter is realized by the method of theoretical calculation and experimental verification, having such disadvantages as big workload, long development cycle, and difficult early-stage verification. In this paper, taking the design of a 4th-order high-pass filter circuit with a cut-off frequency pass band of 10 kHz as an example, a filter design method based on the electronic design automation(EDA) technology is introduced, in which the special design software Filterlab2.0 is employed to select the filter circuit parameters and structure, and the circuit simulation software Multisim13.0 is adopted to verify the filter parameters. This method can complete the design of required filter quickly, accurately and intuitively. A filter prototype is built for simulation test, and the result verifies the feasibility of the proposed filter design method.

Influence of Negative Gradient Sound Velocity Profile on Anti-ship Effect of Active Acoustic Homing Torpedo

XIE Yong, LIU Qing-hui, ZHU Wen-zhen, WANG Xin

2017, 25(1): 018-21. doi: 10.11993/j.issn.1673-1948.2017.01.004

[Abstract](1052) [PDF 764KB](430)

Abstract:
The anti-ship effect of an active acoustic homing torpedo depends on the performance of acoustic homing system and the sound velocity profile characteristics. Aiming at the negative gradient sound velocity profiles in the shallow sea areas of China, this paper analyzes the effect mechanism on sound ray propagation, and concludes that the negative gradient sound velocity profile may lead to attacking failure of active acoustic homing anti-ship torpedo, shortened homing distance, and discontinuous target tracking, which will affect the anti-ship effect of active acoustic homing. Finally, an example is given. This research may provide the basis for further enhancing effectiveness of active homing anti-ship torpedo.

A Complete Coverage Path Planning Method of UUV under Complex Environment

WEN Zhi-wen, YANG Chun-wu, CAI Wei-jun, MAO Jin-ming

2017, 25(1): 022-26. doi: 10.11993/j.issn.1673-1948.2017.01.005

[Abstract](1193) [PDF 682KB](944)

Abstract:
A new method with high coverage rate and low repetition rate is presented to solve the complete coverage path planning problem for an unmanned underwater vehicle(UUV) under complex environment. The method integrates ant colony algorithm and biologically inspired neural network. In this method, environment is modeled with grid cell and biologically inspired neural network, and the neuronic activity is introduced into the ant transition probability formula. As a result, the shortcomings of ant colony algorithm, e.g., scanning and learning environment in advance are needed and computation is complicated, are overcome, and the defects of high complexity, high randomness and high repetition rate of the biologically inspired neural network are avoided. Simulation experiment in complex environment shows that complete coverage path planning of UUV can be efficiently implemented by the proposed method, and the method can get rid of the dead corner in the shortest route. The present method has higher coverage rate and lower repetition rate. This research may provide a reference for further improvement of the UUV complete coverage path planning in dynamic environment.

Optimization of Topology Structure for Torpedo Control System Based on Genetic Algorithm

LIN Yang, SUN Jiong, LIU Kai, ZHANG Bai-yong

2017, 25(1): 027-31. doi: 10.11993/j.issn.1673-1948.2017.01.006

[Abstract](1187) [PDF 367KB](389)

Abstract:
Aiming at the optimization of communication network architecture of torpedo control system, a simple model is established for a certain type of torpedo. The total length of the lines for connection in the control system and the reliability of network are chosen as the optimizing target, the solving efficiency of genetic algorithm and the ability of searching global optimal solution are improved, and the solution to the target optimization problem is achieved by programming with MATLAB. The result shows that the optimized topology structure is better than the original one in the total length of connection lines and the network reliability.

Design of Shell-integrated Condenser for Underwater Power System with Closed-loop Cycle

HAN Yong-jun, YANG Cheng-shi, PENG Bo, GUO Zhao-yuan, LU JUN, MA Wei-feng, WANG Jin-zhong

2017, 25(1): 032-36. doi: 10.11993/j.issn.1673-1948.2017.01.007

[Abstract](1053) [PDF 454KB](434)

Abstract:
A mathematical model of shell-integrated condenser is established for an underwater power system with closed-loop cycle. Design and calculation software is developed for the condenser by using MATLAB. Comparing the calculations with the actual test data, it is proved that the design and calculation software is of high reliability. It can provide data reference for design-ing and developing shell-integrated condenser, optimizing structure and performance of the shell-integrated condenser, and improving efficiency of design and development.

Modeling and Simulation of Counter-rotating Turbine Power System for Underwater Vehicle

ZHAO Min-quan, WANG Xin-ping

2017, 25(1): 037-44. doi: 10.11993/j.issn.1673-1948.2017.01.008

[Abstract](1317) [PDF 441KB](468)

Abstract:
To study the power system of counter-rotating turbine for an underwater vehicle, a control scheme of counter-rotating turbine power subsystems is proposed. The first stage turbine is controlled by the fuel flow, the second stage turbine is controlled by adjusting the proportional relief valve′s pressure of a sea water pump to change the absorbing power. Then mathematical models of the closed cycle control system are established respectively for each stage turbine. The speed changing characteristics in constant depth and the steady speed characteristics at varying depth of the underwater vehicle are simulated. The results indicate that the changing characteristics of the parameters are in accordance with the expected values and the changing process of the power system is fast and steady.

Reliability Evaluation Model of Torpedo in Preventative Maintenance

WANG Hao, CHEN Dong-ke, LIU Qing-hui

2017, 25(1): 045-48. doi: 10.11993/j.issn.1673-1948.2017.01.009

[Abstract](805) [PDF 475KB](327)

Abstract:
For the shortcomings of torpedo performance test technology adopted in torpedo preventive maintenance, a torpedo reliability evaluation model is established based on the actual torpedo preventive maintenance and the Markov chain model so as to understand changing trend of torpedo reliability under certain preventive maintenance strategy. Further, the rationality of a preventive maintenance strategy is demonstrated. The research process and the design of the model focus on the actual working conditions of a torpedo in preventive maintenance period. The quantitative results obtained can comprehensively and systematically describe the reliability variation of a torpedo during the period of preventative maintenance, and can facilitate the determination of torpedo maintenance strategy.

An Evaluation Method of Autonomous Navigation Accuracy for Autonomous Underwater Vehicle

YE Hao-liang, WANG Song-lin, HE Cheng-gang

2017, 25(1): 049-53. doi: 10.11993/j.issn.1673-1948.2017.01.010

[Abstract](1262) [PDF 296KB](747)

Abstract:
To evaluate autonomous navigation accuracy for an autonomous underwater vehicle(AUV), the concept and definition of autonomous navigation accuracy specification are clarified via reference for related methods in other industries. Considering the test methods for engineering, the requirement for test sample of AUV autonomous navigation accuracy is proposed, the constraint conditions are set for screening the test samples, and sample selection is standardized. Two evaluation methods of AUV autonomous navigation accuracy, i.e. counting method and measurement method, are presented, and actual data are used for calculation. The result verifies the reasonability and feasibility of the proposed evaluation method of AUV autonomous navigation accuracy.

Evaluation Method of Failure Free Test Data for Exponential Life Distribution Products

FU Zhao-hui

2017, 25(1): 054-58. doi: 10.11993/j.issn.1673-1948.2017.01.011

[Abstract](773) [PDF 243KB](410)

Abstract:
The reliability test of weapon loading often produces failure free test data. By making use of the memoryless of exponential distribution, it is generally considered that the failure free test time of n same-type products is equal to the total test time of n products for one product to work without failure. In engineering applications, however, this method has limitation. This paper explains the reason why this method cannot be fully used for calculation by making use of the bathtub curve, that is, there is a mistake when the total load time is up to the failure condition. To solve this problem, a modified method for calculating the reliability of loading is proposed, and the lower confidence bound is given. The feasibility of the proposed method is verified by an example.

Safety Analysis of EED in Nuclear Electromagnetic Pulse Radiation

WANG Dian-xiang, ZHANG Rui, JI Xiang-fei, YAO Hong-zhi, ZHAO Tuan

2017, 25(1): 059-64. doi: 10.11993/j.issn.1673-1948.2017.01.0012

[Abstract](912) [PDF 879KB](483)

Abstract:
To solve the problem that the 2.3/23 ns high-altitude nuclear electromagnetic pulse(HEMP) radiation proposed in United States military standard can seriously affect weapon system and electric explosive device(EED), the testing system of HEMP radiation effect was employed to perform safety research on EED under electromagnetic radiation. The relationships of bridge-wire resistance and foot line length of EED with the induced current and energy under HEMP radiation were obtained. The results show that: 1) the energy consumption rate of the bridge-wire resistance is constant; 2) the energy consumed by the resistance rises and the induced energy rises linearly with the bridge-wire resistance; 3) the peak induced current in bridge-wire depends on the equivalent impedance of equivalent antenna, and the change in bridge-wire resistance will not affect the peak induced current; and 4) the peak induced current increases linearly with the foot line length, and the induced energy increases exponentially with the foot line length. This research may provide design basis for improving the adaptability of EED to nuclear electromagnetic pulse effect.

Equivalent Relationship between Cylindrical Charge and Spherical Charge for Underwater Explosion

ZHANG Chi-yu, GUO Rui, LIU Rong-zhong, CHEN Liang, YANG Yong-liang

2017, 25(1): 065-70. doi: 10.11993/j.issn.1673-1948.2017.01.0013

[Abstract](1335) [PDF 665KB](466)

Abstract:
Both cylindrical charge and spherical charge warheads are commonly used, so their underwater explosion performances attract more attention. However, the existing empirical formulas are only for spherical charge. To understand if the underwater explosion pressure field of cylindrical charge can be described by the empirical formulas for spherical charge, This paper qualitatively analyzes the influences of the orientation and the ratio of length to diameter on pressure field of cylinder charge underwater explosion, obtains a relationship expression of far field shock waves of cylinder charge and cycle charge by contrasting the pressure fields of cylindrical charge and same amount of spherical charge, and deduce an approximate empirical formula for cylinder charge by considering the empirical formulas for spherical charge. In addition, simulation is conducted to verify the accuracy of the deduced formula. This research may provide the basis for optimizing explosion performance of underwater warhead.

Model and Algorithm Optimization of Suspension Depth Charge Deployment in Limited Area

REN Lei, JIA Yue, LI Wen-zhe

2017, 25(1): 071-76. doi: 10.11993/j.issn.1673-1948.2017.01.014

[Abstract](1069) [PDF 352KB](357)

Abstract:
The deployment area of a suspension depth charge is limited when it is combined with other soft torpedo defense weapon. In order to solve the problem of determining the deploying position in the limited area, a mathematical model of two-side datum point deployment is established for suspension depth charge intercepting a torpedo by analyzing the operational process and the trajectory characteristics of an incoming torpedo. The objective function and the constraint condition are optimized, the optimal solution by combining analytical calculation with logic judgment is obtained, and the accuracy of the model and algorithm are verified by an example. This study may provide a reference for determining deploying position of a suspension depth charge in a limited area.

Optimal Attack Speed and Leading Angle of Torpedo under Energy Constraint

SUN Quan

2017, 25(1): 077-80. doi: 10.11993/j.issn.1673-1948.2017.01.015

[Abstract](851) [PDF 374KB](594)

Abstract:
Higher speed is not always appropriate in a torpedo attack because the torpedo energy is limited. The faster of the torpedo runs, the shorter its range becomes. This paper presents a method for solving the optimal attack speed and the leading angle under the constraint of minimum energy through theoretical analysis and formula derivation. Based on the solution the relations among the optimal attack speed, the optimal leading angle, the energy and the target board angle are analyzed. The results may facilitate torpedo application and trajectory design as well as energy planning for whole course of far-range cruise torpedo.

2017 Vol. 25, No. 1

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