Table of Content

30 June 2006, Volume 27 Issue 3

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Paper

Design and Experimental Study for Exhaust Pipes of Pressure Wave Supercharged Diesel Engine

JI Chang-wei, ZHAO Yong, MA Hui, HAN Ai-min, LI Chao

2006, 27(3):  385-389.  doi:10.3969/j.issn.1000-1093.2006.03.001

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NOx and soot emissions from diesel engines can be greatly reduced by pressure wave super-charging .The exhaust pipes in the diesel engine matched with pressure wave supercharger (PWS) need to be redesigned. The exhaust gas must be stable in pressure before rushing into the PWS, and the requirements for installation have to be met also. In this paper, the lateral and center ported diver-gent exhaust pipes are designed, modeled geometrically and analyzed structurally based on a 3D design software CATIA, to determine the structure of two exhaust pipes. The flow analysis for these two ex?haust pipes is carried out using a flow analysis software ANSYS. The better exhaust pipe was deter?mined synthetically and tested in bench. The test results show that PWS, comparing to turbo charg?ing, is superior under low engine speed, close under medium speed and inferior under high speed in power and emission.

Dependability Evaluation of a Vehicle System by Simulation Method

YANG Yu-hang, LI Zhi-zhong, ZHENG Li

2006, 27(3):  390-393.  doi:10.3969/j.issn.1000-1093.2006.03.002

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The vehicle system studied in this paper belongs to such a type of complex repairable systems whose subsystems follow various failure distributions and conform to arbitrary failure and repair distri-butions. Failure data of the subsystems are sometimes not sufficient, reliability test sample sizes tend to be small. Monte-Carlo technique combined with Bayes method was used to evaluate its dependaoility (reliability and maintainaoility) . Following the queuing rule, “first-in，first-out” the logic relationship of dependability was established by means of repair priority and event lists. Simulation outputs the en?tire history of a mission, statistics of reliability and maintainability parameters and provides the basic data for system reliability design and maintainability management.

A Wavelet Estimation Method of Density Function

YANG Fu-feng, RTJI Xiao-ting, WEI Wei-bo

2006, 27(3):  394-398.  doi:10.3969/j.issn.1000-1093.2006.03.003

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In order to obtain the sample message of normal distribution, a normal hypothesis is used for the estimation of test data in general. But many engineering practice problems are not in accord with normal distribution hypothesis, for example, there is a world of difference between the impact point distribution of multiple launch rocket and the normal distribution. A new method, a wavelet estima?tion method of density function, is introduced, which estimates the non-normal sample distribution. Probability density function was estimated with orthogonal symmetrical wavelet base function, test da?ta with noise were dealt with by threshold. The dispersion of projectile is estimated with this method so that the deviation of test data from normal hypothesis is avoided. The instance analysis indicates that this method is effective.

A Calculation Method of Reinforced Concrete Beam Under Low Velocity Impact

WANG Ming-yang, WANG De-rong, SONG Chun-ming

2006, 27(3):  399-405.  doi:10.3969/j.issn.1000-1093.2006.03.004

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The characteristics of local and total deformation of reinforced concrete beam under low ve?locity impact were systematically summarized and analyzed in this paper, fhe calculation method of quasi-elastic and plastic processes for reinforced concrete beams was presented considering the local ef?fect of projectile according to theory of bending. The calculation formulas of reinforced concrete beams under low velocity impact were obtained by establishing the simplified calculation models.

An Innovative Method of Determining the Kinetic Friction Coefficient Based on the Virtual Prototype of Runaway Escapement

WANG Li-xin, HUANG Wen-Iiang

2006, 27(3):  406-409.  doi:10.3969/j.issn.1000-1093.2006.03.005

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An innovative method of determining the kinetic friction coefficient based on the virtual pro?totype of runaway escapement was present. The friction calculation model of revolute joint in ADAMS was described in detail. According to the references and experiment, the range from 0.03 to 0.15 of the kinetic inction coefficient of runaway escapement was put forward. The 2D/3D mixed virtual pro-totype of the runaway escapement was constructed and the kinetic friction coefficient at 0.01 was found using the bisection search method.

A Study on the Precision Press Loading Technique of a Synchronous Multi-point Explosive Circuit

WEN Yu-quan, JIAO Qing-jie

2006, 27(3):  410-413.  doi:10.3969/j.issn.1000-1093.2006.03.006

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According to the design of a synchronous multi-point explosive circuit and the requirements to synchronization, a “one-in-four-out” explosive circuit was designed and a new loading tecnnique— the exact press loading technique was used and tested. The synchronization of explosive circuit was theoretically analyzed through error analysis and measured by probes. The results show that the error analysis method can be used to analyze the synchronization of multiple point detonation wave output. With this charge method, the synchronization attained is less than 80ns，approaching the value theo?retically estimated, and could satisfy the need of EFP warheads.

Simulation of Adsorption of Alkanes and Xheir Per- fluorine or Chlorine Substitutes on TATB Crystal Surfaces

ZHANG Chao-yang

2006, 27(3):  414-417.  doi:10.3969/j.issn.1000-1093.2006.03.007

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The adsorption of alkanes and their per-fluorine or chlorine substitutes (the numbers of car?bon atoms are 1，2，3，4，5，10，20) on TATB crystal surfaces was simulated by MD (NVT) and MM(COMPASS forcefield) methods in Discover/Material Studio program package. The simulated re?sults show that for molecules possessing the same number of carbon atoms, the interactions between the chlorine substitutes and crystal surfaces of TATB are stronger than those between the per-fluorine suostitutes or alkanes and crystal surfaces of TATB, due to the molecular deformations which bring the decrease in energy of molecules on surfaces. It can be indicated that the interactions between polymers and TATB will decrease if hydrogen or fluorine has excessively high ratio in fluorine-polymers. For most molecules (the number of carbon atoms is less than 5), the interactions between TATB crystal surfaces and molecules decrease as follows： (010) > (100)〉（001)，and this may be related to the for?mation of hydrogen bonds; but this order can not be observed for larger molecules with more than 5 carbon atoms.

A Multi- sensor Target Recognition System in the Complex Interference Environment

PU Shu-jin, YANG Shen-yuan, ZHAO Zhong-kai，ZHAO Kun

2006, 27(3):  418-421.  doi:10.3969/j.issn.1000-1093.2006.03.008

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For multi-sensor target recognition in a complex interference environment, the environment is variational and the data processed is massive. If conventional methods are used, reliability and ro-bustness of the system hardly meet the requirements. To solve these problems, a multi-sensor target recognition system was presented based on the ensemble of neural network classifiers in the complex in?terference environment. Several fusion methods were simulated, and the results show that the system is practicable and it can effectively enhance the efficiency and robustness of target recognition system.

A New Algorithm of Net Layer Trouble-shooting—RJRBFNN

LI Qian-mu, XXJ Man-wu, ZHANfG Hong, LIU Feng-yu

2006, 27(3):  422-427.  doi:10.3969/j.issn.1000-1093.2006.03.009

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Based on rough sets and radial basis function, a RRBFNN algorithm was proposed for the design of network fault diagnosis system. Reduced information table is obtained implying that the number of evaluation criteria is reduced with no information loss through the rough set approach. This reduced information is used to develop classification rules and train neural network to infer appropriate parameters. The rules developed by RA-Neural network analysis show the best prediction accuracy if a case does match any of the rules. It is capable of overcoming several shortcomings in the existing diag?nosis systems, such as a dilemma between stability and redundancy, and provides tne functions such as gathering oi aata, analysis, storing and response. Since the essence of fault diagnosis is a kind of map?ping ，an artificial neural network model is adopted to deal with the mapping relations, categorizing the network faults. The experimental system implemented by this method shows fine diagnostic abili?ty.

A Novel Frequency Domain Adaptive Beamforming Algorithm

ZHang Xiao-fei, XU Da-zhuan

2006, 27(3):  428-431.  doi:10.3969/j.issn.1000-1093.2006.03.010

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A novel frequency domain adaptive beamforming algorithm was presented. The received sig?nal from array antennas was analyzed, ana it shows that different DOAs correspond to different spatial frequency, and the received signal is the result of addition of different spatial frequency signals. I hat is the foundation of adaptive beamformer in frequency domain. This novel adaptive beamforming algo?rithm uses FF 丄 for the received signal, passes the band-pass filter and finally uses the LMS algorithm to implement adaptive beamforming in the frequency domain. FFT-ed signal has a better decorrelation and leads to better convergence of LMS algorithm. Band-pass niter can suppress the interference sig?nals outside oi the band. Band-pass filtered signal can reduce its dimension greatly, which leads to re?duce the amount of calculation and storage of LMS algorithm, and the convergence will speed up fur?ther. Theoretical analysis and simulations demonstrate that this algorithm converges faster than the conventional adaptive beamforming algorithm, and that it has better performance, requiring less amount of calculation. Finally, the algorithm is no more complex and can be implemented easily, and can be widely used. Besides, the beamforming algorithm is robust to coherent resource.

State Filter of Singular 2—D Roesser Models

SHENG Mei, ZOU Yun

2006, 27(3):  432-436.  doi:10.3969/j.issn.1000-1093.2006.03.011

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The problem of state estimator design for stochastic singular 2—D Roesser models subjected to white noises in both the state and measurement equations was studied. The well-known Kalman fil?ter design was extended to singular 2—D Roesser models that minimizes the variance of the estimation error of state vectors. The filtering pro Diem of jump-mode reconstructable singular 2—D Roesser models was solved through the method of “scanning row by row . Explicit formulas of the estimator was de?rived and based on which a numerical procedure was proposed to demonstrate the validity of the de?signed filter.

Computer Simulation of Digital Projection Based on Arbitrary Scanning Locus of Cone-beam X-ray Source

YANO Min, LANG Tian, WEI Ying

2006, 27(3):  437-441.  doi:10.3969/j.issn.1000-1093.2006.03.012

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In order to analyse the reconstruction algorithm based on different scanning loci, the projec?tion data of corresponding scanning locus must be obtained in advance. By analytic geometry method and solving quadratic equation, a computer simulation algorithm oi digital projection under arbitrary scanning locus was proposed. The algorithm is based on the rules of attenuation of monochromatic X- rays. Through mathematical modeling and computer simulation, digital projections of ellipsoid, and cylinder in circular and helix scanning modes are exemplified respectively, which are proved to be cor-rect by FDK and PI-Iine reconstruction algorithms. The algorithm is very useful to analysing the re-construction method of different scanning modes.

Research on Radar Range Equation in Land Clutter Environment

KONG Qing-yan, CHEN Zhong, HU Bing

2006, 27(3):  442-445.  doi:10.3969/j.issn.1000-1093.2006.03.013

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The effect of different distribution of clutter on detection ability of radar was analyzed, and the radar range equations in clutter environment were derived. The relationships among RCb, detec-tion range and detection probability were discussed and the simulated results were given as examples by using Matlab.

Moving Object Detection Algorithm in Video Sequences

WANG Hua-wei, LI Cui-hua, SHI Hua,WEI Feng-mei

2006, 27(3):  446-450.  doi:10.3969/j.issn.1000-1093.2006.03.014

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An efficient algorithm of detecting moving objects in video sequences was proposed. An adaptive background model was built and subsequently the background model is updated by a fore?ground object classification based background update algorithm which can resolve the deadlock” prob?lem efficiently. An improved shadow suppression algorithm which combines HSV color information with first-order image gradient information was exploited to segment shadows. Extensive experiments results on indoor and outdoor image sequences demonstrate that the proposed system can effectively de?tects moving objects and suppresses their shadows.

Implanentation of a Complex Self- correlation Method on ADCP and Its Realization on Fixed DSP

ZHU Hao, LIU Wen-yao, WANG Xiao-dong, HAO Yong-jie,LIANG Jie

2006, 27(3):  451-457.  doi:10.3969/j.issn.1000-1093.2006.03.015

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A Clustering Algorithm Based on Mathematical Morphology

ZHANG Yong-mei, HAN Yan，ZHANG Jian-hua

2006, 27(3):  458-462.  doi:10.3969/j.issn.1000-1093.2006.03.016

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In order to find directly some meaningful cluster structures from spatial database, an algo?rithm on the basis of mathematical morphology was presented after analyzing some available algo?rithms .The algorithm realizes cluster of spatial ODjects through closing. The algorithm can not only complete 3D spatial clusters at a time, but also handle cluster in-convex and complicated objects rapid?ly. Analyses and experiments show that the algorithm is effective.

3-D Noise Measurement and Analysis for a Low-light-level ICCD Imaging System

LI Sheng-cai, XU Zong- chang, XlAO Shun-wang

2006, 27(3):  463-466.  doi:10.3969/j.issn.1000-1093.2006.03.017

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A new method was advanced for calculating 3-D noise expediently. The method has the practical merit for 3-D noise measurement and quality evaluation of discrete low-light-level imaging sys?tem. The 3-D noise of ICCD(Intensifier Charge Coupled Uevice) imaging system is measured and an?alyzed with the help of digital image processing technology and measurement system. The result of measurement ana analysis accords well with the performance of a low-light-level ICCD imaging sys?tem.

Infrared Imaging Fuse Target Recognition System

LUO Lai-bang, CHANG Ben-kang

2006, 27(3):  467-470.  doi:10.3969/j.issn.1000-1093.2006.03.018

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An infrared target real-time recognition system applied to the test prototype of smart ammu?nition is introduced in this paper. The construction and composition of the whole system are given. And the methods oi infrared target image real-time processing are described, in detail. Since the high?speed DSP -TMS320F240 is used as a micro-processor, the whole system appears succinct. The exper?imental result shows that the system is of high reliability and capability of anti-jamming, and meets the fuse requirements.

Novel Image Stabilization Technology Based on Soft-platform

YANG Chang-qing, WANG Xiao-tong, XU Xiao-gang,JIN Liang-an, FU Jian-guo

2006, 27(3):  471-474.  doi:10.3969/j.issn.1000-1093.2006.03.019

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A new image stabilization technology based on soft-platform was studied. By replacing hard- platform with computer algorithm, it can eliminate the high frequency image jitter of shipborne opto?electronic- imaging system. To overcome the shortcoming of optical flow estimation in real time, a new algorithm based on optimizing vector-block segmenting was provided. Experimental results show that soft-platform possesses good stability and observing precision for imaging system, and based on the comparison between optical flow estimation of Gaussian pyramid method and the algorithm in the pa?per, the new algorithm can reduce the working time for more than 25 % .

Mathematical Model and Simulation oi rorpedo Weapon System Effectiveness Evaluation

JIA Yue, SONG Bao-wei, LIANG Qing-wei

2006, 27(3):  475-479.  doi:10.3969/j.issn.1000-1093.2006.03.020

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The tactical and technical indexes of the torpedo weapon system are important factors on e- valuating their effectiveness. The reliability and maintainability of torpedo weapon systems were re?searched to calculate the availability matrix. Dependability matrix model and capability matrix model were established by the theory of stochastic process. Finally, the torpedo weapon system effectiveness models were established and simulated using a computer.

A Study on the Components Used on Pre-cooled ATREX Engine

SHANG Xu-sheng, CAI Yuan-hu, XIAO Hong

2006, 27(3):  480-484.  doi:10.3969/j.issn.1000-1093.2006.03.021

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Air turbo ramjet engine with expander cycle (ATREX) is a new type of high Mach turbine based combined cycle(IBCC) engine, based on existing turbojet engines developed in Japan. The au?thors analyze ATREX characteristics, explain its development superiority compared with the tradition?al engine, summarize its characteristics and key techniques in their development. It was found from the literatures that adopting liquid hydrogen cooler and pre-cooling method for ATREX engine can ex?pand the regular turbojet working scope and satisfy the request of the supersonic aircraft or TSTO air?craft .

Spare Availability Model for k-out-of-N system with Different k in Different Phases

ZHANG Tao, GUO Bo, Wu Xiao-yue, TAN Yue-jin

2006, 27(3):  485-488.  doi:10.3969/j.issn.1000-1093.2006.03.022

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For some special k-out-of-N systems, k is different when they are in different phases. A mathematical model and its algorithm for spare availability of k-out-of-N system with different k in different mission phases were presented to provide a decision on the quantity of spare parts in hand for -implementing the different missions. An example was given.

Theoretical Investigation and Experimental Verification of the simulation of Thermal Characteristics of Metal and PCM Plates

YE Hong, ZHANG Shuan-qin, ZHUANG Shuang-yong, YANG Tai-rong，WANG Xi-yao

2006, 27(3):  489-493.  doi:10.3969/j.issn.1000-1093.2006.03.023

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A one-dimensional thermophysical model was used to investigate the simulation of the ther?mal characteristics of metal and PCM plates theoretically, the optimized parameters were obtained by calculations. Based on the calculated results, one Kind of organic PCM was selected to verify experi?mentally the model and a good match between the theoretical and experimental results was achieved. The results of this investigation provide the design rules and key materials for the application of PCMs to false target.

Application of a Fusion Modeling Method Based on LrA-HP Networks to the Performance Prediction of the Core-driU

WU Qi, HU De-jin, ZHANG Yong-hong, XU Hong-jun

2006, 27(3):  494-497.  doi:10.3969/j.issn.1000-1093.2006.03.024

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A new algorithm for the performance prediction of the diamond core-drill was presented. The development of the algorithm is based on BP neural networks and GA algorithm. The presented GA-BP algorithm uses BP neural networks to generate GA-BP model. By computing error gradient and checking it with given error, local minimum position is identified. At this time, if BP neural network is in local minimum position, GA algorithm is used to optimize the BP neural networks’ weight. The main advantage of the presented algorithm is the fact that it can solve disadvantages of BP neural net?works, such as low rate of convergence, easily falling into local minimum point and so on. The effec?tiveness and accuracy of the algorithm is demonstrated by the performance prediction experiments of the diamond core-drill.

A Study of Predicted Maintenance Strategy for a Flexible Manufacturing System

ZHANG Li-bin, SU Jian, CHEN Rong, JIA Ya-zhou

2006, 27(3):  498-501.  doi:10.3969/j.issn.1000-1093.2006.03.025

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A theoretical model of predicted maintenance strategy was established for a FMS based on a study of the practical running fault record and maintenance experience on the FMS CH-85. Weibull distribution fitting model of FMS fault interval was set up, and after relevant analysis, the theory and methods of establishing predicted maintenance scheme for the system were proposed.

Critical Security Computation About Breeder System of Spherical Shell in the Case of Water Submergence

FU Guang-zhi, HE Bin, SHANG Ai-guo, LI Jun

2006, 27(3):  502-505.  doi:10.3969/j.issn.1000-1093.2006.03.026

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A Monte-Carlo method is one of the effective measures in nuclear critical security analysis. It was used to study the critical variation about breeder system of multi-region spherical shell in the case of water submergence. The results show that the water submergence has a very distinct influence on the critical value Keff under water submergence depth d ≤ 15 cm, at >15 cm, Keff is essentially a constant.

A Study of Surface Hardening Hased on Creep-Feed Wet Grinding

LIU Ju-dong, WANG Gui-cheng, CHEN Kang-min, JIA Zhi-hong

2006, 27(3):  506-509.  doi:10.3969/j.issn.1000-1093.2006.03.027

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Grind-hardening of non-quenched steel was performed with creep feed grinding mode and different cooling conditions. Microstructure and properties of the surface hardened layer were com?pared .The results show that more satisfactory hardened layer could be acquired through an appropria?tely chosen grinding conditions adopting creep-feed wet grinding. Compared with results through dry grinding, the surface hardened layer through wet grinding has the same martensite structure and changing trend, but its martensitic gradient is steeper under the action of coolant. The residual com?pression stress and wear resistance of the hardened layer after wet grinding are improved. Also the depth of the hardened layer and the entirely hardened area is reduced. The procedure can find applica?tions in the field of grinding and metal surface modification.

The CAD/CAE FechnoIogy of Electromagnetic Low Pressure Die Casting for Aluminum Alloys

XU Hong, HOU Hua, YANG Jing,DANG Jing-zhi

2006, 27(3):  510-514.  doi:10.3969/j.issn.1000-1093.2006.03.028

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The CAD/ CAE technology of electromagnetic low pressure casting for aluminum alloys was proposed. The CAD/CAE model was established based on the study of export pressure determination method of electromagnetic pump, tne pressurization criterion design technology, velocity initial condi?tion and predication method of shrinkage and porosity of low pressure die casting process. Also the fill?ing and solidification were simulated in low pressure casting process. The results of experiment and simulation show the exportation pressure of the electromagnetism pump can be regulated and controlled accurately by controlling the electric current and the defect predication considering the pressure condi?tion is more accurate. The filling of electromagnetism pump low pressure casting is steady, and the pressurization control is precise. The electromagnetism pump low pressure casting is the advanced cast?ing method to produce nigh quality aluminum castings.

Short Papers

Shortest Path Analysis and Its Application in Network Systems

WANG Hai-mei，ZHOU Xian-zhong

2006, 27(3):  515-518.  doi:10.3969/j.issn.1000-1093.2006.03.029

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According to the characteristics of digital map, a key technique of shortest path analysis was presented, and a shortest path analysis system was realized by a practical and efficient DIKB algorithm based on the digital map. In the paper some techniques such as the vector map representation, con-struction of the topological structure of network and efficient implementation of shortest path algorithm etc. are described in some detail.

An Automatic Inspection System for Angle Between Axes Based on LabVIEW and IMAQVision

DANG Li-ping, LIU Jun-hua

2006, 27(3):  519-523.  doi:10.3969/j.issn.1000-1093.2006.03.030

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A non-contact axes parallelism measurement method based on image processing and analysis was presented. After determining the position of laser spot, the distance between the center of laser spot and its theory position of axis is known, and then parallelism error between axes is computed. The algorithm including a morphological filter and threshold choice with idea of eye vision possesses good filter and robust performance and solves the identification and the location for a visible object and an infrared spot in different atmosphere environment. Based on IMAQVision and LabVIEW, a ma?chine vision system for tiny angle measuring on product line was built, and used to inspect and adjust a parallelism error among axes of a heavy missile launcher. The angle measurement accuracy is equal to that of optical theodolite, the system is satisfactory.

Composite Detection Performance of Magnetism and Laser Fuzes

ZHANG Yan-mei

2006, 27(3):  524-527.  doi:10.3969/j.issn.1000-1093.2006.03.031

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The principle of detection of the composite system composed of magnetism and laser used in fuzes was discussed. The mode of information fusion and detection fashions of the composite system were analyzed. The calculation methods of the theoretical threshold, the false alarm probability and the detection probability for the parallel, serial and single detection systems were given. Performances of detection for the system under different modes were studied. Simulation results show that composite detection has great advantages over a single mode alone. Conclusions drawn from this theoretical analy?sis are benefitial to the choice of detection means and the design of thresholds and other related parame?ters.

Active and Semi-active Control for Airplane Landing Gear

JIA Yu-hong, WANG Jian-jun

2006, 27(3):  528-532.  doi:10.3969/j.issn.1000-1093.2006.03.032

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The absorber system of landing gear has a decisive influence on the taxiing performance of airplane. According to the real-time feedback for the ground input, the active and semi-active control can reduce impact and fatigue loads greatly by adjusting the stiffness and dampness in time. Further?more, the variations of vertical displacement and pitch angle of aircraft are obviously reduced, and the comfort and operation performances are improved greatly. Compared with the active control, the semi?active control landing gear can obtain the resemblance taxiing performances, and has more practical value because oi its simple structure ana lower cost.

Experimental Techniques and Analysis

Experimental Study and Numerical Simulation on Laser Ignition Processes

ZHANG Xiao-bing, YUAN Ya-xiong, YANG Jun-yun, ZOU Rui-rong

2006, 27(3):  533-536.  doi:10.3969/j.issn.1000-1093.2006.03.033

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A multi-point laser ignition simulator was designed and multi-point uniform ignition experi?ments was conducted. With the high-power solid pulse laser, laser is produced and transmitted by op?tic glass window and optic fiber. The pressure mstory at four ports was detected. It is found that the pressure distributions are almost uniform and the pressure waves are small by 500 fiber and 900 nber. The comparison of single point laser ignition and conventional electric primer indicates that laser simultaneous ignition is obvious and dangerous pressure waves are obviously restrained. A two-phase flow model of the multi-point laser ignition processes was established and numerically simulated. The numerical results are well consistent with those of the experiments.

A Study of the Lifetime of RF Pumped Waveguide CO2 Lasers Based on Zeolites

LIU Su-jie, XIN Jian-guo

2006, 27(3):  537-539.  doi:10.3969/j.issn.1000-1093.2006.03.034

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A new method to prolong operation time of CO2 laser was presented. Zeolites are used, to ab?sorb a great quantity of fresh gas CO2, and when the concentration of CO2 begins to decrease caused by dissociation in discharge, CO2 gas is released from the zeolites, abating the difference between the real concentration of gases and the optimum one. This is useful to prolong the lifetime of sealed-off C〇2 lasers in the working gases deterioration way. Precise measurements were made by using quadrupole mass spectrometer Balzers QMS200. The experimental results prove tnis new technology to be fea?sible .

An Experimental System of Digital CCD Imaging for Control Parameter Optimization

SONG Yong, HAO Qun, WANG Yong-song, YANG Guang

2006, 27(3):  540-544.  doi:10.3969/j.issn.1000-1093.2006.03.035

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The control parameter optimization is an important base for improving image quality and the applicability of micro imaging system in complex environment. The design of experimental system of CCD imaging system for control parameter optimization was discussed in detail. First, the signal pro-cessing of digital CしD imaging system was analyzed. The real time control of CCD driver and digital processing circuit, and man-machine interaction were achieved by the design of digital CCD imaging module and control module. The experimental results indicate that the image quality of digital CCD ex?perimental system makes a good response to the change of control parameters.

Research Notes

simulation Studies of Coupled Rigid and Flexible Multi-body Dynamics for Multiple Launch Rocket Systems

FENG Yong, MA Da-wei, XUE Chang, CHEN Bing

2006, 27(3):  545-548.  doi:10.3969/j.issn.1000-1093.2006.03.036

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Coupled rigid and flexible multi-body system dynamics was proposed using rigid multi-body dynamics and flexible body dynamics theories. An ADAMS simulation model was established with the ADAMS and ANSYS software. In this model, flexible launch tubes are referred to. Launching dy?namics simulation and analysis of a multiple launch rocket system were performed. Simulation results of the force and the vibration in the whole multiple launch rocket system were obtained. It can be used as a theoretical foundation for investigating dynamic characteristics under the launching process of a MLRS. Additionally, it is of more importance to analyze the initial disturbance and dispersion for MLRS accurately.

A Study on A. C. All-electric Gun Control System in Tanks

ZANG Ke-mao, LI Li-yu, LI Kuang-cheng

2006, 27(3):  549-552.  doi:10.3969/j.issn.1000-1093.2006.03.037

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In this paper, the A. C. all-electtric gun control system for tank is introduced. The eleva?tion suDsystem in the system applies the PMSM drive control system in connection with ball guide screw replacing the complicated electrohydraulic system. PMSM drive control system is also aoolied in the traverse subsystem. The A. C. all-electric gun control system studied has high performance, giving a reduction by 40 % in weight, and by 30 % in volume, increases the efficiency by 35 % as compared with gun control systems currently in use. The calculated service life of ball guide screw is 3 240 h.

Preparation and Catalytic Effect of Nano- structured Iron Oxide for Reduced Smoke Composite Propellant

LIU Jian-min，XU Fu-ming, ZHOU Wei-liang,ZHU Li-xun，GONG Li, YANG Qiong-fen

2006, 27(3):  553-557.  doi:10.3969/j.issn.1000-1093.2006.03.038

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he preparation of a nano-structured burning rate catalyst (ns —Fe2〇3) was presented, which is composed of Fe2O3 nano particles and an inert component. The experiments of ns—Fe2〇3 us?ing X-ray diffraction (XRD) and transmission electron microscope (TEM) show that the active com-ponent in ns—Fe2〇3 is mainly Fe2〇3，the particle size of Fe2〇3 is in the range of 50 ?200 nm, and the shape of Fe2〇3 is irregular. The results of catalytic decomposition of ammonium perchlorate (AP) by ns-Fe2O3 show that, as the amount of ns—Fe2〇3 is increased，the apparent exothermic heat of AP in thermal decomposition is greatly enhanced; the decomposition peak temperature at low-temperature range changes little, but it is continuously lowered at high-temperature range. When 0.25% (by mass percentage) ns-Fe2〇3 is added into reduced smoke composite propellant ( RDX/AP/Al/HTPB), the burning rate at 6 MPa is increased from 6.31 mm/s of the propellant without catalyst to 8.51 mm/s of the propellant with ns—Fe2〇3 catalyst, showing a burning rate increment of 35 % ; the burning rate in?crements of ns-Fe2O3 and common Fe2O3 at 6 MPa are 56% and 31% respectively, as 1% catalyst is added; when 2% ns—Fe2〇3 is added, the burning rate increments at o MPa and 10 MPa reach 69% and 78% respectively, implying an attractive burning rate catalytic property; in the range of 4 ?10 MPa, the pressure exponent of burning rate for ns—Fe2〇3 is lower than that of common Fe2〇3 but higher than those of tert-butyl-ferrocene (IBF) and Catocene (GFP).

Realtime Simulation of Large Scale Sea Battlefield

ZHOU Ming, XU Xiao-gang, ZHU Tao

2006, 27(3):  558-561.  doi:10.3969/j.issn.1000-1093.2006.03.039

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It is a basic work to create a sea wave environment platform before building a sea battlefield simulation system. A new realtime sea wave model which can cover wide area of ocean was proposed. The model can effectively display sea battlefield scene at different climate conditions. By way of opti?mizing the sea color value and the net grid data, a realtime walkthrough system covering the neld of 225 km x 225 km area was built based on a general PC platform.

Temporal Data Management of High Level Architecture

JIANG Xia-jun, WU Hui-zhong, LI Wei-qing

2006, 27(3):  562-565.  doi:10.3969/j.issn.1000-1093.2006.03.040

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High level architecture (HLA) defines an integrated approach that provides a common framework for the interconnection of interactive simulations. Data management is one of the important factors during the implementation of HLA5 especially for temporal data management. A log-based temporal database model was designed, and it can manage the data of simulation in real time. The model provides both snapshot query and schema transformation functions to meet the requirement of run-time using and after-action analysis of temporal data. The latter can also help the HLA gateway to exchange data between different simulation architectures. Introduction of database technology into HLA provides the run-time infrastructure with transaction mechanism, so it can enhance the data management ability in HLA. Experiment shows that compared with the conventional database, the temporal database model can greatly improve the efficiency of temporal data management in simulation environment.

An Acoustic Method for the Detection of Precise Orientation of Bomb Falling Points

CHEN Dong-ming, CHANG Gui-ran, ZHIJ Zhi-Iiang

2006, 27(3):  566-570.  doi:10.3969/j.issn.1000-1093.2006.03.041

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An acoustic method for the location of bomb falling points was provided, integrating acous?tics, electronic technology, digital signal processing (DSP), statistics, radio communication as well as computer application. Acoustic signal is pre-processed by magnifier, filter, A/D converter, then ana-lyzed and processed through DSP system and transfered to the central- control system through radio network. The system accounts for the relative wave transfer time, taking account of factors such as noises, temperature, wind speed and direction, and selects suitable math model to locate the precise position of bomb falling points. The resulting data are remitted to the command operator automatically.

simulation and Analysis of the Distribution of Submarine- launched Missile Carrier Sinkage Trajectory

GE Hui, ZHANG Yu-wen, ZHOTJ Qin-ying

2006, 27(3):  571-576.  doi:10.3969/j.issn.1000-1093.2006.03.042

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The sinking process of the separated carrier from submarine-launched missile is a complex kinetic process, the main influence on the distribution of sinkage trajectory is the distribution of the initial kinematic parameters. The Matlab/Simulink model of the sinking process was established con?sidering the ocean current and wave. The orthogonal experiment method was used to analyse the influ?ence oi initial kinematic parameters on the separated carrier sinkage trajectory. The primary and sec?ondary sequence of the influence of the different initial kinematic parameters on certain trajectory index was found. The result gives credible basis resolving a dash, against the body of submarine from separat?ed carrier.