Table of Content

31 May 2007, Volume 28 Issue 5

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Paper

Theodolite Optimal Disposition in Artillery Duplicate-aim Precision Detection

DONG Qi-shun, JIANG Tao, SU Cheng-zhi

2007, 28(5):  513-515.  doi:10.3969/j.issn.1000-1093.2007.05.001

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The ambulatory amount of artillery tube is one of the primary factors affecting the shooting precision of artillery. A new method of optimal disposition theory of theodolite was presented to detect the duplicate-aim precision of artillery. The experimental results show that the operation and the as?sembly of the. method are simple, convenient, flexible and suitble for indoor and outdoor environ?ments .

An Estimative Method of Deceleration- time of Penetration and Perforation for Concrete Target

GE Tao, WANG Ming-yang, ZHOU Ze-ping, WU Hua-jie

2007, 28(5):  516-519.  doi:10.3969/j.issn.1000-1093.2007.05.002

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The deceleration of projectile during penetrating and perforating to concrete target was stud?ied. Based on new velocity and the resistance expressions of projectile, the prediction model of deceler?ation was established during penetrating and perforating to concrete target. A diameter scale conversion is included in the model. The curves of deceleration versus time were achieved with the model. The comparative analysis between the model and experimental data demonstrates that the prediction is cred?ible.

Study of Sea Wave Clutter Jamming to Pseudonoise Code Fuze

LIU Jing-ping, ZHAO Hui-chang

2007, 28(5):  520-523.  doi:10.3969/j.issn.1000-1093.2007.05.003

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By being aimed at sea wave clutter jamming to pseudonoise code fuze, the average power and reflective coefficient of sea echo signal were analyzed, the statistic characteristic of sea clutter signal was obtained at different sea conditions and polar directions. According to the characteristic, the sea clutter signal was simulated and inputted into pseudonoise code fuze to detect the antijamming abillily of pseudonoise code fuze. The simulated result shows that sea wave clutter jamming has little influence on pseudonoise code fuze, either sea echo signal arrives in the fuze prior to target echo signal or target echo signal is submerged m sea echo signal.

Algorithms to Extract Thermal Image Edge

ZHOU Pei-de, FU Meng-yin, HUANG Yuan-shui, LIU Yi-tong

2007, 28(5):  524-527.  doi:10.3969/j.issn.1000-1093.2007.05.004

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The searching algorithm of edge grey levels in column and row was proposed. The basic principle of the algorithm is as follows. Starting from the pixel of highest grey level and computing the disparity in grey level of each two adjacent pixels within the same column of image, the grey levels of pixels where the disparity reaches maximum and minimum are taken as the upper and lower thresholds of image edges in that column and that row. Thresholds are searched in each column and row of im?age. Besides that, the other edge detection algorithm was presented based on golden section, together with multi-threshold and limited area, ^computational complexity of new algorithm was analyzed. Ex?perimental results show that new algorithm extracts the edge of thermal image quickly and meets the practical demands of automatic target recognition.

Research on Optimal Distribution of Radar Jamming Resource Based on Zero-one Programming

SHEN Yang, CHEN Yong-guang, LI Xiu-he

2007, 28(5):  528-532.  doi:10.3969/j.issn.1000-1093.2007.05.005

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Precision guided weapons make up large scale in the modern air attack campaign. Ground- to-air jamming system becomes an important force, besides fighter plane, air-defense missile and anti?aircraft artillery. It becomes the important problem how to use limit ground-to-air radar jamming re?source in order to defend ground target from air attack. Optimal distribution of radar jamming resource under the air-defense background was proposed. It includes assessing radar menace grade, evaluation of radar jamming effect and optimal distribution model ot jamming resource. The characteristic of the modern multi-beam jammer was considered. The computer simulation indicates the practicability of the model ?

Bistatic Radar Localization Based on Best Linear Unbiased Estimation

GUO Hui-dong, ZHANG Xin-hua, WANG Wei-song，YE Qiong-Iong

2007, 28(5):  533-538.  doi:10.3969/j.issn.1000-1093.2007.05.006

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According to the principle ot Dest linear unbiased estimation, A target localization algorithm for bistatic radar was proposed by pseudo measuring value after coordinate conversion. The expression of the Cramer-Rao lower bound for bistatic radar was given. The numerical simulation of the algorithm was carried out at different noise conditions, simulation results show that the target localization accu?racy for bistatic radar is effectively improved, and the Cramer-Rao lower bound and simulation results are better than that of a weighted least square method.

Positioning Algorithm for Ship’s Navigation Signal Based on Nonlinear UKF

MA Ye, WANG Xiao-Tong, LI Bo, FU Jian-Guo

2007, 28(5):  539-542.  doi:10.3969/j.issn.1000-1093.2007.05.007

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According to the mechanism of the unscented Kalman fliter(UKF), a continuous nonlinear model of BeiDou (GPS/RLC)/DR integrated navigation system was established, and a corresponding algorithm was proposed. Based on prior statistic characteristic of random variables, state variables are disintegrated into 2n + I samples in the light of specific rule, and the nonlinear function is linearized by statistic linear regressive technology. By this means, linearization errors are reduced effectively. The experiment with actual data from warship shows that UKF algorithm ’ s estimation precision and the system stability are much better than those of EKF algorithm.

Analysis of Far Field Intensity Distribution with Resonator Length for a Rectangular Waveguide CO2 Laser

WU Xing-fei, YANG Jing, XIN Jian-guo

2007, 28(5):  543-546.  doi:10.3969/j.issn.1000-1093.2007.05.008

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The analysis of the far field spatial intensity distribution of a rectangular waveguide laser was presented which is in good agreement with the experimental results ? The analysis results show that the rectangular waveguide CO2 laser can manifest a far field intensity distribution of coherent spatial sup?pressed single peak, which is similar to that from a phase coupled waveguide array laser, and its far field intensity distribution changes periodically with the increase of the resonator length.

Application of a Particle Swarm Optimization Algorithm to Optimizing Radar-net

LIU Yi-an, MENG Xian-Hai, YANG Hua-ming,TANG Shuang-tian

2007, 28(5):  547-550.  doi:10.3969/j.issn.1000-1093.2007.05.009

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In order to arrange radar network reasonably and effectively in the defence region with the limited radar resources, the optimal object function which is satisfied with requests of continuity and strictness in radar network coverage was established according to each radar ’ s contribution to the de?fense regional coverage, then a group of particles for each radar was randomly generated by a PSO al?gorithm, and the candidate solution of each radar，s position in the feasible solution space was searched. At the same time, each radar’s candidate position was coordinated by a installed harmony controller to satisfy the global optimal solutions of radar network arrangement. The simulated result indicates that the method is effective and feasible.

Sound Intensity Vector Estimation and Time Delay Estimation Combined to Determine the Bearings of Ship Volume Target

SHI Jie, XIANG Jing-lin, LUO Jian,HAN Peng

2007, 28(5):  551-556.  doi:10.3969/j.issn.1000-1093.2007.05.010

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The method to determine the bearings of the three highlight sections of a ship based on a non-typical vector sound intensity array was proposed. The array consists of four sensors those are ar?ranged to form spatial cross and adjustable space between the sensors. The bearing of the low frequen-cy noise radiated by the midship and the section between the midship and stern was determined by sound intensity vector. And the bearing of the stern which radiates high frequency noise was deter?mined by time delay estimation. AU these methods are based on the same array. The computer simula?tion and the experiment conducted in a semi-anechoic chamber prove that this method can effectively distinguish the three sections of the ship.

Performance Analysis for Random Noise Ultra-wideband Radar Signal

ZHANG Xian-yi，SU Wei-min, GU Hong

2007, 28(5):  557-560.  doi:10.3969/j.issn.1000-1093.2007.05.011

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The random noise ultra-wideband radar signal was analyzed ana its power spectral function was also given. Through the theoretical analysis and computer simulation, the statistical peak sidelobe level (PSL) of compression wave of the correlation receiver, and the resolved ability were studied. The simulation result shows that this signal possesses lower PSL better resolved ability in comparison with the LFM ultra-wideband radar signal on a certain condition.

Simulation of Infrared Images of Small Target and Sea and Sky Background

WANG Mei，SHEN Guotu, YANG Bao-cheng,CAI Ji-guang, GAO Jing, DONG Zhan-hai

2007, 28(5):  561-564.  doi:10.3969/j.issn.1000-1093.2007.05.012

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A physical model for infrared thermal image simulating was developed, which takes account of the characteristics of both small target and sea and sky background. The dynamic infrared images of combining target with background were obtained by simulating computation. And in order to simulate the images formed by a detector, the noise signals of the detector that are assumed to be Gauss-dis?tributed were added to the.combined images. The model and the simulation method can be used to pro?vide simulated aynamic infrared images for target recognition.

Conversion of Torpedo’s Environment factor for Lake and Sea Test Based on Small Sample System

SONG Baowei, SHAO Cheng, MAO Zhao-yong, SHAO Xu-fei, LI Jia-wang

2007, 28(5):  565-567.  doi:10.3969/j.issn.1000-1093.2007.05.013

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There is a little information of torpedo’s lake and sea test, and the torpedo’s life doesn’t obey representative Iite distribution. It can ’ t reflect the actual condition that the conventional methods are used to convert the environment factor for torpedo’s lake and sea test. The conversion model of the environment factor for torpedo，s lake and sea test was set up by using the GM (I, 2) model of the grey system theory. For the merit of the grey system theory, the problem of lacking data can be solved. The results show that the method is easy, realistic, and has high conversion precision, which can be taken as good references.

A Modified Range-Doppler-Range Imaging Algorithm in Squint Mode for Space-borne SAR

YANG Jin-pei, HU Xue-cheng, ZHU Li,LIU Zhong

2007, 28(5):  568-571.  doi:10.3969/j.issn.1000-1093.2007.05.014

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In a range-Doppler-range (R-D-R) imaging algorithm, the phase compensation and focusing are made based on the phase characteristic of Fourier spectrum of radar echoed signal. Compared with other algorithms, the computational load of the method is much reduced. The R-D-R algorithm was here modified significantly to make it apply to airborne and space-borne SAR imaging in squint mode. The modified algorithm was deduced mathematically. The flow chart of the approach and the simulat?ed result of a point target imaging were also given. Meanwhile, the approach was applied to space- borne SAR imaging and the outcoming image for Radarsat-I raw data was given. The results indicate that the approach can be applied to airborne SAR and space-borne SAR image processing.

Optimal Gliding Guidance in Vertical Plane for Standoff Released Guided Bomb Unit

HOU Ming-shan

2007, 28(5):  572-575.  doi:10.3969/j.issn.1000-1093.2007.05.015

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Based on nonlinear dynamics and kinematics, optimal gliding guidance for guided bomb unit in vertical plane was studied. The guidance law was designed under minimum energy loss index. To avoid the difficulties in solving two-point-boundary-value problems, the steady solutions of the joint states in regular equations were suggested to be used. With these considerations, a quasi-closed, opti?mal gliding guidance law was obtained. The guidance law is described by the angle of attack in a simple nonlinear equation. Iterative computation method can be easily used to get the optimal angle of attack. The further simplified, direct computation algorithm for the optimal angle of attack was also given. The guidance properties are compared with that of maximum lift-to-drag angle of attack control. The simulation results demonstrate that the quasi-closed, optimal gliding guidance law can improve the gliding phase terminal performance with significant increase in the altitude and much little decrease in the speed.

Study of an Air-to-ground Missile Countermine Simulation System

YANG Man-zhong, YIN Jian

2007, 28(5):  576-580.  doi:10.3969/j.issn.1000-1093.2007.05.016

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In order to evaluate weapon system operational effectiveness in general, the necessity of de?veloping an air-to-ground missile countermine simulation system was proposed. The air-to-ground mis?sile countermine simulation system was analyzed, a study on system modeling by UML was made, a system conception model and its detail were showed, a system frame for the simulation system based on HLA was designed. An exploitive process of a simulation application system based on HLA was giv?en. The erection of distributive interaction simulation system environment provides an infrastructure for evaluating the operational effectiveness of air-to-ground missile ?

Augmented Eigenvector of Multibody System Coupled with Rigid and Elastic Bodies and Its Orthogonality

RUI Xiao ting, YUN Lai-feng, LU Yu-qi

2007, 28(5):  581-586.  doi:10.3969/j.issn.1000-1093.2007.05.017

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In multibody system dynamics, the orthogonality of eigenvector is the precondition to solve the dynamic response of system using the classical modal analysis methods. For a multibody system coupled with ngia and elastic bodies, the eigenfunction does not satisfy the orthogonality under ordi?nary meaning. A new conception—augmented eigenvector was introduced, and by means of which the orthogonality problem of eigenvectors of multibody system was overcome. The constitution method, the orthogonality condition and the orthogonality proving for augmented eigenvector and its importance were expatiated. After the orthogonality of augmented eigenvector is acquired, the coupling of coordi?nates in dynamics equations can be released, which makes it possible to analyze exactly the dynamic re?sponse of multibody system using the classical modal analysis method.

Two dimension Numerical Computation of the Spallation in a cylindrical Steel rube Loaded by Sliding- implosion

WANG Yong-gang, HE Hong-liang, WANG Li-li,JING Fu-qian

2007, 28(5):  587-591.  doi:10.3969/j.issn.1000-1093.2007.05.018

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By means of an explicit nonlinear dynamic finite element computer code Ls-dyna, the spalla?tion in a cylindrical steel tube loaded by sliding-implosion was studied, and with a Tuler-Buctcher dam?age model, the physical process of spallation was reproduced. The simulation results show that I) the refraction angle of shock wave increases with the increase of propagative distance at the interface of ex?plosive and the cylindrical steel tube; 2) the oscillations of inner free surface velocity become weaker, but the periods get longer due to the interaction between the oblique incident wave and the reflection wave; 3) a critical value exists in the thickness of explosive leading to the spallation inside the cylindri?cal steel tube, and the initial spall thickness increases with the increase of the explosive thickness.

Study on the Time Distribution of Some New Type failure for Markov Repairable Systems

RAN Lun, ZHENG Zhi-hua, CUI Li-rong

2007, 28(5):  592-597.  doi:10.3969/j.issn.1000-1093.2007.05.019

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The time distribution of the i th new type failure for Markov.repairable systems was stud?ied. The Laplace transformation function of the density function of the distribution was obtained by the Ion-channel theory and the Laplace transformation. The Laplace transformation functions of prob?ability distribution density functions for the difference between the times, at which the j th and j-1 th new type Iailures happened, were derived in the cases of with and without precondition. Some numeri?cal examples were presented to illustrate the results obtained in the paper. The conclusion is applicable to the research of Markov repairable systems, and is a useful extension to the general theory of Markov process.

Experimental Techniques and Analysis

Experimental Investigation on the Effect of Mixed Additives on Homogeneous Charge Compression Ignition Combustion

LI Chao, JI Chang-wei, HE Hong,SHEN Zi-you, HE Chao, LI Yun-zhe, Ma Chong-fang

2007, 28(5):  598-603.  doi:10.3969/j.issn.1000-1093.2007.05.020

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The experimental research of homogeneous charge compression ignition (HCCI) combustion process with mixed additives was carried out by the modified fourth cylinder of a four-cylinder diesel engine. The influence of mixed additives on the HCCI combustion process was investigated. Experi?mental results indicate that the mixed additives are better than the single additive for HCCI fuel, caus?ing ignition and heat release timings to be advanced and the peak of heat release rate to be increased at different engine speeds and steady operating conditions. Moreover, with the increase of engine speed, the influence of mixed additives on HCCI combustion is more obvious. In addition, mixed additives are benencial to improving HCCI engine misfire at the high speed, and make the engine operating stable at specified speeds.

Experimental Study on the Influence of High Speed Plasma Gas and Flight Projectile on the Inductive Setting in Muzzle

HUANG Xue-gong, CHEN He-juan, WANG Zhi-xin

2007, 28(5):  604-607.  doi:10.3969/j.issn.1000-1093.2007.05.021

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The muzzle inductive setting is a dynamic process of high speed. Based on analyzing the pro?cess of the projectile flying through the inductive setting field, an experimental method was studied to test high speed plasma gas and high speed projectile influencing on the inductive setting system. Three tests were designed. Phe real-time coupling curves of the inductive setting signal were tested by cou?pling test coils: The experimental results indicate that the electromagnetic field formed by high speed plasma gas can influence the signal transmitting of the inductive setting system, and the influence can be lowered by opening vent on muzzle; the high speed projectile can change the distributing characters of the electromagnetic field in the inductive setting zone, which reduces the amplitude of the inductive coupling signal.

Instantaneous Thrust Measurement of an Attitude Control Solid Rocket Motor Based on Dynamic Compensation Technology

OUYANG Hua-bing, XU Wen-gan

2007, 28(5):  608-612.  doi:10.3969/j.issn.1000-1093.2007.05.022

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For the instantaneous thrust measurement of a certain small solid rocket motor, the differ?ence between the instantaneous thrust measurement and general one was pointed out, on the basis of analyzing the measurement principle of solid rocker motor. Based on the characteristic of the instanta?neous thrust measurement, a dynamic digital filtering compensation method was represented. By a combined method of identification modeling, dynamic compensation and computer simulation, the dy?namic mathematic modeling oi the measurement system was set up and the compensation digital filter of the model was designed. Thus the dynamic response characteristic of the system was improved and the instantaneous thrust of solid rocker motor was measured. By the metKod, the testing thrust of the attitude control solid rocket motor was deal with. The results show that the dynamic digital filter com?pensation method is effective in the instantaneous thrust measurement of solid rocket motor.

Study of Explosive Welding Technology of Railway Connector

ZHANG Guo-wei, SUN Xue-qing, ZHANG Yu,LIU Pei-qing

2007, 28(5):  613-616.  doi:10.3969/j.issn.1000-1093.2007.05.023

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Railway signal transmission is the key to insure train run safely. The railway connector for signal transmission is important equipment to guarantee railway signal transmission and reduce electric current imbalance. From the point of view of engineering practice, the explosive welding technology of railway connector was studied theoretically and experimentally, the appearance, tensile strength, mi?cro configuration of welding junction and welding area after explosive welding were detected. Experi?mental and detective results show that the junction quality to concent railway with connector by means of explosive welding is reliable, which lays the foundation for the technology’s engineering practice.

Short Papers

Observability for Two dimensional Single Observer Tracking Based on Bearing-only Measurements

XU Zhi-gang, SHENG An-dong

2007, 28(5):  617-620.  doi:10.3969/j.issn.1000-1093.2007.05.024

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The problems of no unique solution for bearing-only target (BOT) locating and tracking come into existence sometimes, namely unobservable. By utilizing the method of vector transformation and cnaracteristic of linear matrix equation, the problem of observability for BOT in noise-free bearing measurements from single observer was discussed based on the target and observer traveling in the 2-di?mensional space. A proposition that BOT with constant acceleration remains unsolvable was presented and proved. By proving the proposition, it is also showed that some motion parameters ratios of target can be estimated under certain condition satisfied by measurement bearing sequence and time sample. When the proposition is extended to arbitrary rank of maneuver for the observer and the target, and the rank of target maneuver is higher than that of the observer maneuver, the important proposition, in which BOT remains unobservable property, was deduced. I he vector method and the given proposi?tion provide the guidelines for further analyzing the maneuver strategy of the observer.

Research Notes

Design and Implementation of Tracked Multi-purpose Engineering Vehicle Training Simulator

ZHANG Qi, SUN Shaowen, LI Wen-hong, SUN Wei

2007, 28(5):  621-624.  doi:10.3969/j.issn.1000-1093.2007.05.025

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An efficient tracked multi-purpose engineering vehicle training simulator was developed by using technologies of digital signal processing, multimedia, sensors, simulation modeling and real-time visualization simulation based on windows platform. The architecture of simulator and implementation of each module are proposed, with focus on design methods of data acquisition, dynamics modeling, visual simulation, sound simulation and assessment simulation. The system was put into practice and got satisfactory results.

An Optimization Design Method for the Configuration Parameters of Spring Hydraulic Floating Mechanism in Gun

WANG Gang, YAO Yang-wu, ZHANG Xiao-bing,LUO Jian-guo

2007, 28(5):  625-628.  doi:10.3969/j.issn.1000-1093.2007.05.026

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As an effective way of reducing the recoil force, the key technology of the floating mecha?nism is how to match properly the relation between floating mechanism configuration parameters and automatic mechanism kinematic parameters. An optimal design method of floating mechanism of auto?matic weapon’s spring hydraulic buffer was presented, and the corresponding design software was also programmed by VC. According to the software, a antiaircraft machine gun and a grenade machine gun floating mechanism dynamic parameters were optimized, and their recoil forces were reduced sharply. The method is proved to be a feasible way in the floating mechanism design.

Model Following Control of Electro- hydraulic Servo System

LI Chang-chun, LIU Xiao-dong, MENG Ya-dong

2007, 28(5):  629-632.  doi:10.3969/j.issn.1000-1093.2007.05.027

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Based on the analysis of the nonlinear factors in modeling electro-hydraulic servo system, the robustnesses of the model following control (MFC) and single loop feedback control were studied and compared. A model following controller was designed for disturbances of hydraulic damp parameters of the system. It is proved by simulation results that more robustness of the model following control to disturbances of parameters of the system is arrived.

Application of a Two-Scan Data Association Algorithm to Multiple Target Tracking

LI Hui, ZHANG An, ZHAO Min, SHEN Ying

2007, 28(5):  633-637.  doi:10.3969/j.issn.1000-1093.2007.05.028

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In view of the computational burden of a traditional joint probabilistic data association algo?rithm, a new two-scan data association method based on an interior point linear programming approach was introduced. The principle of the new algorithm was analyzed, and its performance was compared with one of the traditional joint probabilistic data association algorithm. It can be seen that the new al?gorithm is more effective from the aspects of theory. The new method can be applied to multiple target tracking. The improved accuracy and speed of the new method proved them to be superior to those of the traditional by computer simulation experiments.

Damping Material Optimal Placement in Damping Structure Design

GUO Zhong-ze，CHEN Yu-ze, HOU Qiang,CHE Bi-qin

2007, 28(5):  638-640.  doi:10.3969/j.issn.1000-1093.2007.05.029

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Damping material optimal placement in damping structure design was studied. A mathemat?ical model of the modal loss factor maximum was constructed, and the damping material optimal place?ment was found by evolutionary structural optimization(ESO) . The method is suited for free damping structure and constrained damping structure, by using less material.