水下无人系统学报

A Parameterization Method for Airfoil Based on Composite Mapping Method and B-Spline

ZHANG Shen-rong, CAI Wei-jun, YANG Chun-wu, CUI Xin-shan

2015, 23(3): 161-165. doi: 10.11993/j.issn.1673-1948.2015.03.001

[Abstract](1576) [PDF 415KB](678)

Abstract:
Reducing geometric design variables can improve the computational efficiency of aerodynamic optimization of airfoil. For design feasibility, a parameterization method is proposed, in which a B-spline fitted shape function is transformed into practical airfoil with composite mapping method. The convergence property of this parameterization method is analyzed via some low-speed airfoils. The fitted airfoil profiles are highly approximate to the original ones, and their aerodynamic characteristics show remarkable consistency. In addition, the influence of the shape function control points on the geometric characteristics of airfoil is analyzed, and local control of airfoil profile is achieved. Results indicate that this parametric method can represent known airfoils and modify local airfoil profiles, and can be applied to airfoil optimization.

Simulation on Underwater Inflation Process of Annular Bladder

YE Hui-juan, WANG Xin-ye, ZHANG Ning

2015, 23(3): 166-171. doi: 10.11993/j.issn.1673-1948.2015.03.002

[Abstract](1355) [PDF 448KB](456)

Abstract:
To reveal the underwater inflation process of an underwater vehicle′s annular bladder, mathematical models of the underwater inflation process are built based on the theories of thermodynamics and the elastic constitutive model of elastic body. Simulation is conducted to analyze the factors influencing the bladder′s underwater inflation process. The result shows that the present mathematical models can be used to analyze the change rules of the related parameters during underwater inflation process of an annular bladder, and to simulate floating process of an underwater vehicle.

An Optimization Method of Torpedo Performance Based on Trajectory Simulation

LI Bin, FAN Ruo-nan, NI Wen-xi

2015, 23(3): 172-176. doi: 10.11993/j.issn.1673-1948.2015.03.003

[Abstract](1287) [PDF 1162KB](495)

Abstract:
General performance optimization based on simulation is a new approach for overall design of complex elec-tromechanical product. The overall design of a torpedo involves many disciplines and a large number of parameters. To improve torpedo′s hitting effect, it is necessary to reasonably match theses parameters. In this paper, a method based on trajectory simulation is proposed to optimize general performance of a torpedo, a complete trajectory model is built, and a trajectory simulation library is compiled. Furthermore, an optimum matching simulation is conducted by employing genetic algorithm for some key parameters of trajectory design. The result indicates that the proposed performance optimization method is effective, and can be applied to other parameters of torpedo general performance.

Doppler Elimination Algorithm for Moving Sound Source Position

JIANG Cheng-kun, BAI Jian-bin, CHEN Zhi-fei

2015, 23(3): 177-182. doi: 10.11993/j.issn.1673-1948.2015.03.004

[Abstract](1358) [PDF 585KB](574)

Abstract:
It is of great significance to obtain the position information of the noise source of a moving target, but Doppler effect often exists in the radiated noise. This paper proposes nonlinear interpolation based Doppler elimination algorithm for array re-ceived signal, including single channel and single focus type, single channel and multi-focus type, and multi-channel and multi-focus type. The algorithm can compensate Doppler frequency shift and amplitude attenuation of radiated noise, and so improve the identification and position accuracy of noise source of moving target. The results of outside field test before and after using the Doppler elimination algorithm show that this algorithm can effectively eliminate the Doppler effect, and improve the position accuracy of noise source.

Improvement of Structure and Procedure for Raising Acceptance Rate of Sonar Transducer

BIAN Xiang, WU Yan-ni

2015, 23(3): 183-186. doi: 10.11993/j.issn.1673-1948.2015.03.005

[Abstract](1361) [PDF 291KB](462)

Abstract:
To raise the acceptance rate of sonar transducer in its development and production processes, an equivalent circuit model was built to analyze the factors influencing the acceptance rate. Consequently, a non-polarized piezoelectric ceramic was adopted in the structure of the transducer, and thermal transition of metallic material was applied to the procedure. A prototype of the sonar transducer with the improved structure and procedure was produced and tested. The results indicate that this improvement can raise the acceptance rate of the product.

Low Probability of Intercept Signal and Detection Technology for Torpedo Based on Direct Sequence Spread Spectrum

CUI He, ZHENG Ke

2015, 23(3): 187-195. doi: 10.11993/j.issn.1673-1948.2015.03.006

[Abstract](1420) [PDF 1806KB](457)

Abstract:
Based on the characteristics of low probability of intercept in direct sequence spread spectrum(DSSS) signal, a waveform of DSSS is designed with respect to the principle and feature of DSSS, the method for generating spread spectrum sequence, and the characteristics of the spread spectrum sequence. The best detection method for DSSS signal, i.e. the detection of matched filter, is discussed. The characteristics of low probability of intercept under ideal condition is analyzed for DSSS signal through simulation. Theoretical analysis and numerical simulation show that DSSS signal has bigger product of time and bandwidth, lower density of power spectrum, better resolution performance, random waveform, and it likes white noise, so it possesses good characteristics of low probability of intercept.

Application of IMM to Underwater Maneuver Target Tracking

GAO Wen-juan, LI Ya-an, CHEN Xiao, CHEN Zhi-guang

2015, 23(3): 196-201. doi: 10.11993/j.issn.1673-1948.2015.03.007

[Abstract](1288) [PDF 415KB](458)

Abstract:
For improving the real-time property and reliability of underwater maneuver target tracking, the interacting multiple model(IMM) algorithm is applied to underwater maneuver target tracking. Based on the IMM algorithm, a target maneuvering model and a measurement model are established. Because the tracking accuracy depends on filtering method, the extended Kalman filter(EKF) and the unscented Kalman filter(UKF) are combined with the IMM algorithm, respectively. Simulation shows that the IMM algorithm combined with UKF can achieve higher filtering accuracy, hence can track maneuver target more effectively and reliably.

Analysis of Pulse Water Jet Propulsion Technology Based on Plug Flow Principle

DU Yi-jiao, WANG Yu-cai, JIANG Bin, WANG Zhi-qiang

2015, 23(3): 202-207. doi: 10.11993/j.issn.1673-1948.2015.03.008

[Abstract](1393) [PDF 789KB](620)

Abstract:
To avoid cavitation of a propeller at high rotational velocity, high speed surface ships incline to use water jet propulsion systems. This study is inspired by the conversion of heat into power in high temperature and high pressure gas driving a piston. According to the principles of plug flows, a novel pulse water jet propulsion system is presented with low costs and simple construction, and the model of the water jet propulsion system is established. According to this model, theoretical calculations and numerical simulations are conducted in the expansion process. With the simulation results, the parameters of the model are optimized, thus the relevant parameters which are closer to real working conditions, such as propulsive force and total impulse, are obtained. Calculation results verify the reasonability of the proposed model.

Influences of Grain Parameters on Combustor Interior Trajectory

MA Wei-feng, LU Jun, GUO Zhao-yuan, HAN Yong-jun

2015, 23(3): 208-213. doi: 10.11993/j.issn.1673-1948.2015.03.009

[Abstract](1186) [PDF 518KB](501)

Abstract:
For proper grain selection for the combustor and better design of the grain parameters, the grain for a thermal power torpedo combustor is taken as an example to establish the burning equations of the grain. And on the basis of the simulation and the performance confirmatory test, the influences of the grain parameters on the combustor interior trajectory are obtained. The results show that: 1) of all parameters of ignition grain, burning rate pressure exponent imposes the most significant influences on the peak time and peak pressure; 2) of all parameters of main grain, burning rate pressure exponent imposes the most significant influences on the peak pressure, the stable internal pressure in combustor and the burning time, and initial outside radius of main grain exerts the most significant influence on the peak time. Tests verify the effectiveness of the proposed model and the relevant results. This model satisfies the requirements of engineering practice. It may provide a theoretical reference for design and optimization of the grain, and provide a technical support to prediction of combustor interior trajectory.

Analysis on Reliability of Battery Pack for Underwater Vehicle

GUO Guang-hua, HU Yu-li, HE Fa-yao

2015, 23(3): 214-217. doi: 10.11993/j.issn.1673-1948.2015.03.010

[Abstract](1310) [PDF 287KB](599)

Abstract:
To improve the reliability of power system of an underwater vehicle(UV), in view of the connection mode of Li-ion battery pack of an electric-power UV, the reliability of composite connection of series and parallel connections is analyzed. Different connection modes are calculated, and the mode with the highest reliability is obtained. It is concluded that the connection mode of first series then parallel connection can achieve higher reliability. In addition, the reliability of parallel battery pack is calculated and analyzed based on the load-sharing mode.

Online Calibration Technology of Two-axis Rotation Laser SINS

LIU Yong-hong, LIU Ming-yong, XIE Bo, WANG Hai-miao

2015, 23(3): 218-221. doi: 10.11993/j.issn.1673-1948.2015.03.011

[Abstract](1052) [PDF 258KB](521)

Abstract:
The errors of gyros and accelerometers are the key factors affecting the precision of navigation of laser strap-down inertial navigation system(SINS). Based on the framework feature of two-axis rotation laser SINS, an online calibration method was proposed in this study by taking velocity and position errors as measurement information. This method can implement online calibration when the laser SINS are in both stable and moving conditions. Vehicle-borne test indicates that the error parameters of laser gyros and accelerometers can be calibrated precisely with the proposed calibration method and calibration route in the case without calibration devices such as the calibration flat and precise turntable. This calibration method is simple in principle and implementation, and does not require strict conditions for environment and equipment.

Equivalent Simulation and Real-time Monitoring Device for Torpedo Exercise System Orienting General Development Platform

LI Wei, DENG Peng, WANG Hong-sheng

2015, 23(3): 222-226. doi: 10.11993/j.issn.1673-1948.2015.03.012

[Abstract](964) [PDF 270KB](442)

Abstract:
Focusing on the general utilization requirement of a torpedo exercise system, this paper expounds the structure and workflow of the equivalent simulation and real-time monitoring device for the torpedo exercise system. Based on the design idea of extendable general development platform, the paper elaborates the technical countermeasures and implementation methods in terms of the technical features and applications of Visual Basic, the embedded industrial computer technology, the multi-channel high-speed data collection technology based on DTE3216 and USB20D, the operation interface, and the design progress of software, etc. This device can play the role of actual torpedo exercise system in torpedo testing and debugging, and can realize on-line condition monitoring, reduce equipment loss, and improve work efficiency.

Determination of Index Weights for Evaluating Anti-Torpedo Torpedo′s Operational Effectiveness Based on Dual Fuzziness AHP

SUN Zuo-wei, CHEN Hang, HUANG Qing

2015, 23(3): 227-231. doi: 10.11993/j.issn.1673-1948.2015.03.013

[Abstract](1017) [PDF 356KB](383)

Abstract:
According to the characteristics of an anti-torpedo torpedo, an operational effectiveness evaluation system of the anti-torpedo torpedo weapon system(ATTWS) is established. Considering the fuzziness of experts′ experience in determining index weight in conventional analytic hierarchy process(AHP), dual fuzziness AHP is proposed to determine the index weight for evaluation of ATTWS′s operational effectiveness. A mathematical model is established, and corresponding calculating steps are given. The calculation result indicates that the proposed method is applicable to determination of the index weight for evaluating anti-torpedo torpedo’s operational effectiveness. This method can also applied to other weapon systems which use AHP to determine the index weight.

Application of Condition Based Maintenance to Technical Support of Torpedo

MA Liang, ZHAI Jian-shuai, YE Xin-ling

2015, 23(3): 232-236. doi: 10.11993/j.issn.1673-1948.2015.03.014

[Abstract](718) [PDF 233KB](459)

Abstract:
To promote the application of condition based maintenance(CBM) to the technical support of torpedo weapons and other equipment, the basic idea of CBM is introduced. Taking a torpedo propulsion system for example, the fault features of the torpedo propulsion system is analyzed with respect to the problems in technical support of torpedo weapons, and the application feasibility of CBM to the propulsion system is discussed. Moreover, the analysis process of applying CBM to torpedo propulsion system is analyzed, and the preventive maintenance decision is made.

Evaluation Method and Data Acquisition for Mean Time to Repair of Torpedo

WANG Hao, GAO Jiang

2015, 23(3): 237-240. doi: 10.11993/j.issn.1673-1948.2015.03.015

[Abstract](1169) [PDF 233KB](434)

Abstract:
According to the actual situation and mission requirement of an underwater weapon range, we analyze the time data acquisition and corresponding evaluation method for repair test of torpedo weapon equipment. According to the standard GJB2072 and the data from the repair test of a type torpedo, a time data acquisition model and a test evaluation method of torpedo fault repair time are proposed. Relevant test data prove the validity and operability of the proposed approach. This approach can be applied to the implementation of maintenance and repair test for underwater weaponry, especially for torpedo weapon.

2015 Vol. 23, No. 3

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