Table of Content

30 December 2013, Volume 34 Issue 12

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Paper

Research on the Overload Characteristic of the Automatic Mechanism for Machine Guns

MAO Qing-long， SHEN Wen-jie， SHA Jin-long， SHI Yong-jun

2013, 34(12):  1489-1494.  doi:10.3969/j.issn.1000-1093.2013.12.001

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The designs of the airborne weapons, vehicle mounted weapons and ship-borne weapons are different from those of the weapons used on the ground. Their key point is that shooting action must be ensured on their carrying platforms under changing acceleration in various directions. A systematic research on the overload characteristics of machine guns is carried out using the dynamics theory of automatic weapons and the experiment methods. A dynamical model of the machine guns is established. The motions of automatic mechanism and gun-body are analyzed in detail under all kinds of overload conditions. The kinetic parameters corresponding to every phase are calculated by taking an airborne machine gun for example, and the movement reliabilities of mechanism movement are also deduced from these facts. The results show that the analytical and experimental results are consistent with each other approximately, proving the correctness of the model and the analytical method.

Application of High Acceleration Impact Vibration System in Strength Test of Aiming Devices for Weapon Systems

SONG Lin-sen，SHAO He, SHI Guo-quan

2013, 34(12):  1495-1499.  doi:10.3969/j.issn.1000-1093.2013.12.002

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The impact acceleration curves and impact mechanism of the ball-firing-strength test are analyzed and studied for improving the strength test methods of aiming devices for weapon systems, based on which an integrative impact and vibration system with continuous impact capability and high acceleration value is designed instead of ball firing for strength test of aiming devices of weapons systems. In the strength test of optical sight of a certain small arms, 710 bullets and test cost of RMB 284 thousand have been saved by using this system, which solves the problems of high cost and low efficiency of test to achieve pretty well economic benefit.

Optimization of Dual-mode Warhead for the Conversion of Jetting Projectile Charge and Jet

LI Wei-bing， FAN Fei， WANG Xiao-ming， LI Wen-bin， DING bin

2013, 34(12):  1500-1505.  doi:10.3969/j.issn.1000-1093.2013.12.003

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Summing up the theory analysis, simulation calculation and test study, this paper optimized the dual-mode warhead to achieve the conversion of jetting projectile charge(JPC) and jet (JET). It was analyzed the liner collapse situation under single point detonation and annular detonation by the theory, and optimized the shaped charge parameters, such as liner cone, radian radius, thickness and charge height, by the numerical simulation. Then, it obtained the initiation mode and the matching relations of the shaped charge parameters which could get the conversion between JPC and JET. The JPC was formed by single point detonation, and the JET was formed by annular detonation. The liner cone was chosen 80°~100°, the liner radian radius was 0.1 time charge caliber, the liner thickness was designed in accordance with liner cone, and the charge height is 0.9 time charge caliber. Aimed at the optimal structure, the X-ray imaging test was done, and the error between the test and simulation results is within 8%.

Research on the Algorithm of Signal Sorting and Reference Frequency Estimation of Frequency Agility Radar

YANG Jian， LIU Yu， DI Hui

2013, 34(12):  1506-1513.  doi:10.3969/j.issn.1000-1093.2013.12.004

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Frequency agility mode is widely used in modern radar. Traditional algorithms often result in the increasing batch in signal sorting. This algorithm estimates the frequency of received signals with high precision firstly. The results can be got by dividing the frequency differences of two adjacent signals. Within a certain range, the signals from different radars are sorted by comparing the fractional part of the results. According to the signals from the same radar, frequency dividing coefficients are estimated by the same way. Finally, reference frequency can be gained. Simulation results show that this algorithm can sort the signals from frequency agility radar effectively. And, it can restrain the increasing batch in the signal sorting and recognize the specific emitters accurately.

Image Fusion Quality Assessment Method Based on Phase Congruency and Structural Similarity

ZHANG Yu-zhen， SUN Jia-song， CHEN Qian, GU Guo-hua, FENG Shi-jie，

2013, 34(12):  1514-1520.  doi:10.3969/j.issn.1000-1093.2013.12.005

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Structure contour is very important to the human visual system in the quality evaluation of infrared (IR) and visible CCD fusion images. The phase congruency (PC) image, produced by the PC model, can preserve the structure contour feature of image very well, even if the image brightness and contrast have changed. Therefore, an assessment method based on PC is proposed for these considerations. Firstly, two images, the structural similarity (SSIM) images of the fused image relative to the IR and visible CCD images, are produced by the SSIM model, respectively. Then, two PC images of the IR and visible CCD images are produced by the PC model. Afterwards, the SSIM images are weighted by their corresponding PC images, considering the different visual sensitive levels of two different regions, contour region and residual region. At last, the information-entropy coefficients of the IR and visible CCD images are used as the weights to predict image quality assessment. The subjective and objective indexes of experimental images are extracted, and the nonlinear correlation coefficients and Spearman’s rank-order coefficients (SROCCs) are calculated for the first time. Finally the experimental data are statistically analyzed. The results indicate that the proposed method can present more subjective evaluation results more than the previous evaluation methods.

Cooperative Inertial Navigation System Error Correction and Accuracy Analysis of Multi-missiles

KOU Kun-hu， ZHANG You-an， LIU Ai-li

2013, 34(12):  1521-1528.  doi:10.3969/j.issn.1000-1093.2013.12.006

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In absence of other navigation systems, the inertial navigation system（INS）error of cruise missile will cumulate continuously with time. A novel INS error estimation method for multiple cruise missiles (at least 3 missiles) is proposed, which is based on the passive observation to feature target and the distance information between missiles and INS information without needing of distance information between cruise missile and feature target or altimeter information or airspeed information. Then the influence of geometrical configuration between cruise missile and the feature target on the INS error correction precision is analyzed, and the horizontal and vertical dilutions of precision are deduced, respectively. Finally, the simulation results prove that the validity of the method and the correctness of the conclusion.

Research on Evaluation Method for Quality and Performance of Missile Weapon Based on Rough Set Rule Extraction

LI Jun, MENG Tao, ZHANG Li-xin, ZHAO Shao-ping

2013, 34(12):  1529-1535.  doi:10.3969/j.issn.1000-1093.2013.12.007

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In order to overcome the shortcomings of classical methods, a new quality performance evaluation method for missile weapon is proposed based on the rough set theory, other related machine learning methods and the quality data of missile weapon in its life cycle.

High Resolution Numerical Simulation of Air Explosion

ZHAO Hai-tao， WANG Cheng

2013, 34(12):  1536-1546.  doi:10.3969/j.issn.1000-1093.2013.12.008

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According to the physical characteristics of strong discontinuity at early stage of air explosion and its contact discontinuities at late stage, a new method coupling the ghost fluid method(GFM) with real GFM (RGFM) is proposed to treat the interface. At the initial stage, the situation where high density ratio and pressure ratio co-exist is treated by RGFM, while at the late stage, because explosion pressure, density and velocity, et al. Come close to each other, GFM is used to treat the interface. The moving interface is tracked by Local Level Set method. The governing equations are discredited by high resolution 5th-order weighted essentially non-oscillatory (WENO) scheme and 3rd-order TVD Runge-Kutta scheme. The air explosion is programmed. Using this program, air explosion at different heights and different distances are simulated. The simulation results accord well with the results obtained from empirical formula and experiments, which satisfactorily reflects the shock wave generation, propagation, reflection from the ground, and diffraction of shock wave, and the expansion of explosion products. The result shows that this method can be employed to simulate air explosion, and the explosion wave has good symmetry during propagating. The approach is effective for simulating the interaction of multi-medium flows at high density ratio and pressure ratio.

Orthogonal Wavelet Transform Dynamic Weighted Multi-modulus Blind Equalization Algorithm Based on Dynamic Particle Swarm

HU Ling-ling， GUO Ye-cai

2013, 34(12):  1547-1554.  doi:10.3969/j.issn.1000-1093.2013.12.009

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In order to improve the equalization performance of high-order quadrature amplitude modulation（QAM）signals, an orthogonal wavelet transform dynamic weighted multi-modulus blind equalization algorithm based on the dynamic particle swarm optimization (DPSO-WTDWMMA) is proposed. In the proposed algorithm, dynamic particle swarm optimization algorithm and orthogonal wavelet transform are applied to dynamic weighted multi-modulus blind equalization algorithm (DWMMA). Accordingly, the equalizer weight vector can be optimized by DPSO algorithm, the autocorrelation of the input signals can be reduced using orthogonal wavelet transform, and DWMMA is used to choose appropriate error models to match QAM signals. The theoretical analyses and computational simulations of underwater acoustic channels indicate that the proposed algorithm can be used to obtain the highest convergence rate and the smallest steady mean square error in the equalization of high-order QAM signals.

Material Removal Rate Model of High Viscoelastic Fluid Abrasive Finishing

DONG Zhi-guo， YA Gang， LI Yuan-zong

2013, 34(12):  1555-1561.  doi:10.3969/j.issn.1000-1093.2013.12.010

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Based on the high viscoelasticity nature of abrasive flow machining media and through the analysis of the normal forces and the number of cutting abrasive particles, a material removal rate model for finishing processing of high viscoelastic fluid abrasive is established. The definition and test method of cutting depth of material removal model is given. The tests of cutting depth coefficients of No Ⅰ fluid abrasive for 45 steel, T8 steel and Q235-A material are determined by tubular specimen. The results show that the material removal rate is positive propostional to wall pressure, wall slip speed and the cutting-depth coefficient. The abrasive particle size, abrasive and carrier mixing ratio, the elasticity of the fluid abrasive, the hardness and surface roughness of the work-piece are the determinative factors influencing cutting depth coefficient. And the cutting depth coefficient can be measured by the length and pressure of fluid abrasive flowing on a work-piece surface under the conditions of relatively high viscosity and large flow capacity.

Research on High Quality of Service Two-class Multiplexing Algorithm

BI Ming-xue，PAN Cheng-sheng

2013, 34(12):  1562-1568.  doi:10.3969/j.issn.1000-1093.2013.12.011

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The two-class multiplexing algorithm of advanced orbiting system（AOS）is researched for the characteristic and performance requirement of the space data system. Based on packet length and arrival rate, the packet channel multiplexing algorithm selects the upper limit of packet channel multiplexing time for optimization multiplexing efficiency adaptively. Based on real time character, frame length and data arrival rate, the virtual channel (VC) multiplexing algorithm distributes the scheduling time-slot lengths and numbers adaptively. Then the multiplexing delay, multiplexing efficiency, loss probability and throughput are simulated separately. The simulation results show that the new two-class multiplexing algorithm can restrict the time delay, reduce the probabilities of packet loss and frame loss, enhance the multiplexing efficiency and the throughput to satisfy the quality of service（QoS）requirement such as low time delay, the high throughput and so on for the future space data system.

An End-grinding Wheel with the Phyllotactic Pattern of Abrasive Grain Clusters and Its Mill-grinding Experiments

LYU Yu-shan， WANG Jun， ZHAO Cheng-yi， HE Yan

2013, 34(12):  1569-1574.  doi:10.3969/j.issn.1000-1093.2013.12.012

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In order to achieve the grindability of superabrasive grinding wheel, a new kind of the superabrasive grinding wheel for end-grinding, which has defined abrasive grain cluster pattern, has been designed based on the phyllotaxis theory of biology. The influence of the phyllotactic parameters of the superabrasive grinding wheel on the abrasive arrangement configuration is analyzed, and the super abrasive grinding wheel is fabricated using ultraviolet lithography method and electroplating technology. The results of mill-grinding experiment show that the mill-grinding performance of the grinding wheel can be improved by selecting the reasonable phyllotactic coefficient k and abrasive grain cluster radius r.

Comprehensive Review

Research Advances in Explosives Detection Technique Based on Nuclear Quadrupole Resonance

ZHU Kai-ran, SU Tao, HE Xue-hui

2013, 34(12):  1575-1588.  doi:10.3969/j.issn.1000-1093.2013.12.013

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Nuclear quadrupole resonance (NQR) is a solid-state radio frequency spectroscopic technique, allowing the detection of many high explosives. Unfortunately, the practical use of NQR is restricted by the low signal-to-noise ratio (SNR) and the radio frequency interference (RFI). The parameter estimation and detection for NQR signals are becoming research hot points in NQR. From the perspective of signal processing, some topics related to NQR are analyzed in-depth, such as basic concept, signal model, signal excitation methods, interference suppression and detector for NQR signals. The research status of explosive detection using NQR is summarized, and some directions of further work in NQR and their difficulties are predicted.

Research Notes

Study on Measuring Method of Refractive Index of Shock Wave in Muzzle

WANG Bao-yuan， CHAO Hong-Xiao， SHAO Xiao-jun， HENG Gang， LI Bao-hui

2013, 34(12):  1589-1593.  doi:10.3969/j.issn.1000-1093.2013.12.014

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A new measuring method is proposed for refractive index of shock wave at muzzle according to the technical difficulty of such measurement. In terms of non-contact laser measurement principle, a system is developed for measuring the refractive index of shock wave at muzzle. The computational formula is deduced and the measurement procedure is offered for refractive index of shock wave. The refraction phenomena of shock wave were observed and the measured value of refractive index is obtained by taking a certain gun for example. The measurement results show that the measured value of refractive index is 1.000 480 at 2 m in front of muzzle. The measuring method provides an experimental support for the measurement error analysis of projectile attitude in bore and the magnitude of muzzle motion.

A Velocity Vector Estimation Method Based on Radar Extended Target

FAN Jian-peng, LU Zai-qi, FAN Hong-qi, FU Qiang

2013, 34(12):  1594-1598.  doi:10.3969/j.issn.1000-1093.2013.12.015

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For the target performing relatively uniform linear motion in the fuze phase, a velocity vector estimation algorithm is proposed based on least square method using the measurements of Doppler velocities and angles of multiple scattering points obtained by the seeker radar. The estimation can be used to predict the explosion point and detonation time, thereby greatly enhancing the fuze performance. Numerical simulations have demonstrated the effectiveness of the proposed approach.

A New STAP Method for Near Space MIMO Radar

LI Wei， LIANG Yong-qiang， WU Hao-tian， WANG Xing-liang， ZHANG Qun

2013, 34(12):  1599-1602.  doi:10.3969/j.issn.1000-1093.2013.12.016

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For the moving target indication (MTI) function of multiple-input multiple-output（MIMO）radar, the uniform array can only bring poor performance, the sparse array brings grating lobes which lead to the blind speeds and the limited length of antenna array on size-fixed platform. An antenna array optimization method is proposed, which is used to lower the minimum detectable velocity (MDV). Combining the array structure together with binary phase orthogonal codes which are designed to get high correlation and cross-correlation performance, high space time adaptive processing (STAP) performance is gotten with limited aperture length. The different STAP performances of various antenna array structures are compared through simulation, thus testifing the effectiveness of the method.

Statistical Inference of Accelerated Life Test with Competing Failures Based on Three-parameter Weibull Distribution

ZHANG Xiang-po, SHANG Jian-zhong, CHEN Xun, ZHANG Chun-hua, WANG Ya-shun

2013, 34(12):  1603-1610.  doi:10.3969/j.issn.1000-1093.2013.12.017

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Three-parameter Weibull distribution (TPWD) has a higher potential for data fitting and a more reasonable physical meaning for life evaluation to describe the life distribution of products that have the characteristics of progressive failure such as wear, fatigue, corrosion and aging failure. Therefore, it is widely used in reliability analysis of products. Based on the properties of TPWD and practice of accelerated life test (ALT), the statistical inference method of ALT with competing failures when all the failure modes are three-parameter Weibull distribution is studied. The maximum likelihood estimation（MLE）model for parameter estimation is also established. Result of application example proves that the statistical inference method and MLE model are correct. The MLE model fits the practice of product life distribution and can provide very good estimation results.

Aircraft Support Process Time Analysis Based on Graphic Evaluation and Review Technique

WU Yong， PAN Xing， KANG Rui， MA Lin

2013, 34(12):  1611-1615.  doi:10.3969/j.issn.1000-1093.2013.12.018

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To deal with the uncertainty problem about the logical relationship and time of aircraft support activities, a support process model based on random network is built by analyzing the aircraft support operating process. The support operating time is solved by graphical evaluation and review technique (GERT), and the solution steps are given. A support process example is studied to demonstrate the effectiveness and applicability of the proposed methodology. According to sensitivity parameter analysis, the corresponding suggestions on aircraft support operations are presented.

Feature Selection Based on Chaos Search

SHEN Qing-ming， YAN Li-jun， GAO Jian-min， ZHAO Jing

2013, 34(12):  1616-1619.  doi:10.3969/j.issn.1000-1093.2013.12.019

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To improve the efficiency of feature selection, a feature selection method based on chaos search (CSFS) is proposed. Firstly, a mapping model for feature candidates and chaotic variables is established，which maps the feature candidates to the chaos space and realizes the interconversion between them. Secondly, the feature selection is carried out by means of the evolution of the chaotic variable. Finally, the classifier is used to evaluate the obtained feature vector. The features of weld defects are taken for example to verify the proposed method, which is compared with a gene-algorithm-based feature selection (GAFS) method. The experimental results demonstrate that the computation time of CSFS is only 61.1% of that by GAFS in the case of obtaining the feature vectors with the same recognition performance.

Experimental Study of Magnetic Liquid Seal with Large Gap and Multiple Magnetic Sources

YANG Xiao-long， LI De-cai， XING Fei-fei

2013, 34(12):  1620-1624.  doi:10.3969/j.issn.1000-1093.2013.12.020

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In some special applications, especially in the military industry, a magnetic liquid sealing technique is needed to solve the problem of leakage in the large gap. To improve and verify the pressure capability of magnetic liquid seal with large gaps, a magnetic liquid sealing structure with multiple magnetic sources is designed. The sealing capability and self-healing capability of magnetic liquid seal with multiple magnetic sources with 0.4 mm, 0.5 mm, 0.6 mm and 0.7 mm gaps are investigated by using experimental methods. The relations between the experimental results of magnetic liquid seal with multiple magnetic source and the theoretical results of magnetic liquid seal with single magnetic source are analyzed. The results show that the sealing capability and self-healing capability of magnetic liquid seal with multiple magnetic source decrease with the increase in gap height; the pressure capabilities of magnetic liquid seal with multiple magnetic source are 4.7, 3.8, 2.8 and 2.5 times of that of a magnetic liquid seal with single magnetic source for four different sealing gaps. In addition, the magnetic liquid seals with large gaps and multiple magnetic sources have good self-healing capabilities.