Table of Content

31 December 2009, Volume 30 Issue 12

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Paper

Study on Heat Transfer of Diesel Engine of Armored Vehicle at Different Operating Conditions

LUO Qing-guo, LIU Hong-bin, GUI Yong,NIE Bin

2009, 30(12):  1569-1573.  doi:10.3969/j.issn.1000-1093.2009.12.001

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The fluid-solid coupled heat transfer model of the diesel engine was built up by the CFD software. Through the bench test of the diesel engine, the simulated results were contrasted with the tested results to proof the accuracy. Considering the design requirements of the intelligent cooling sys?tem, the changed inlet temperature regularity of the system and its reason were further studied at dif?ferent loads of 2 200 r/min、2 000 r/min and 1 900 r/min, to provide reference basis for designing prop?er control strategy of the system.

An Experimental Research on High Velocity Steel Fragments Perforating UHMWPE FRP Laminates

WANG Xiao-qiang, ZHU Xi, MEI Zhi-yuan

2009, 30(12):  1574-1578.  doi:10.3969/j.issn.1000-1093.2009.12.002

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The different thickness UHMWPE FRP (URP) laminates impacted by 3.3 g cubic high ve?locity fragments were studied. According to the ballistic experimental results and the theoretical analy?sis, the linear relation between ballistic limit vBL and area density ρad was confirmed; the versatile ex?periment relation between vr and ρad was found based on that relative parameters in the experiential re?lation of residual velocity were expressed by the function of ρad. The predicted values of ρad and of the cubic high velocity fragments impacting URP using the experiential relations are consistent with the experimental results. The two experiential relations can be used for predicting residual velocity and ballistic limit of the cubic high velocity fragments impacting URP.

Observation and Analysis of Coronary Cracks Beneath the Crater in Armor-plate

WANG Meng，HUANG De-wu, RONG Guang,LIU Yan，YANG Ming-chuan

2009, 30(12):  1579-1583.  doi:10.3969/j.issn.1000-1093.2009.12.003

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Embedding tests of 30CrMnMo armor-plate were performed by fired small-caliber rod armor piercing projectile, and microstructures of the section of crater were investigated with scanning electron microscope and X-ray diffraction. The results show that besides formed adiabatic shear bands near the crater, coronary cracks are also found distinctly at the location of 1 ?2 mm beneath the crater. GDro- nary cracks beneath the crater are all generated, whether the armor piercing core is tungsten heavy al?loy or tungsten fiber reinforced composite. In the process of penetration, the parts between the crater bottom and the coronary cracks are first broken and consumed, second the new coronary cracks near the crater can be produced again. It reveals that the crater in armor-plate is extended deeply by layer and layer. The reason of producing coronary cracks is that the materials are suddenly unloaded by bro?ken fragment, which can cause the interaction of release stress waves. The tested result also indicates that adiabatic shear bands and coronary cracks can be joined at near crater to result in the initial dam?age in armor-plate.

Ballistic Modeling and Numerical Simulation of Cluster Bomb with Piston Dispensing and Guiding Tube

HUANG Bei, WANG Hao, TAO Ru-yi

2009, 30(12):  1584-1590.  doi:10.3969/j.issn.1000-1093.2009.12.004

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Under the condition of piston dispensing of cluster bomb, a new dispensing mechanism with guiding tube was proposed; the working principles of single and double combustion chambers were an?alyzed ;the numerical method of dispensing and dispersing processes of cluster bomb was explored; the interior ballistic equations in dispensing process and the models of submunition dispersion were built; the numerical simulation was performed by the equations and the models mentioned above. The char?acteristics of piston dispensing of cluster bomb were summerized systematically; the dispersing efficien?cy of bomblets in the air was augmented by combining piston dispensing with guiding tube with rota-tion of cluster bomb; the moving and dispersing rules of bomblets in the air were given by the model and the simulation. The investigated results provide theoretical references for dispensing process research, structural engineering design, structural optimization and the submunition dispersion effect analysis.

Anti-jamming Performance Evaluation of Linear Frequency-modulated Continuous Wave Fuze Based on Ambiguity Function Incision

ZHAO Hui-chang, ZHOU Xin-gang

2009, 30(12):  1591-1595.  doi:10.3969/j.issn.1000-1093.2009.12.005

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Based on the analysis of active jamming mechanism and ambiguity function, the methodolo?gy of ambiguity function incision evaluating the anti-active-jamming performance of linear frequency- modulated continuous wave (LFMCW) fuze was put forward. The area of the ambiguity function inci?sion is computed at a certain height which is determined by the radio fuze principle and its receiver sig?nal processing. The smaller the computed area becomes, the stronger the anti-jamming performance gets. This methodology was applied to the evaluation of the anti-jamming performance of linear fre?quency modulated continuous waveform ranging fuze. It demonstrates that the anti-jamming perfor?mance of saw-tooth frequency modulated continuous waveform ranging fuze is stronger than that of symmetrical frequency modulated continuous waveform ranging fuze, and the anti-jamming perfor?mance difference of them becomes smaller when the modulation bandwidth becomes wider; the effect of modulation time on LFMCW fuze is small. The computed results by an example show that the eval?uation methodology is impersonal, reasonable and computable, which can be use for practical purposes.

Preparation and Study of LaFeO3 and α-Fe203 for 2，4, 6-Trinitromethylbenzene Photocatalytic Degradation

WEI Zhi-xian, LIU Hai-yan, ZHANG Xue-jun,LI Yan-bin

2009, 30(12):  1596-1601.  doi:10.3969/j.issn.1000-1093.2009.12.006

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Perovskite-type oxide LaFe〇3 and a-Fe2〇3 with high specific surface areas were directly syn?thesized by stearic acid solution combustion method. The obtained powders were characterized by XRD, SEM, FT-IR, UV-Vis DRS and XPS techniques. Photocatalytic degradation of simulative wastewater of 2, 4, 6-trinitromethylbenzene (TNT) were preliminary studied using solar/UV illumi?nated LaFe〇3. The experimented results show that 0.000 5 mol LaFeO3 under ultraviolet has the same photocatalytic activation as it does under solar; the degradation rate of TNT is 51% within 1 h; under ultraviolet, the catalytic activity of LaFe〇3 is higher than that of a-Fe2〇3 which is due to the high con?centrations of surface-adsorbed oxygen and hydroxyl of LaFe03.

Research on Electrostatic Spark Sensitivity of RDX-A1 in the Process of Roller Mixing

LU Ming, ZHAO Yue-bing

2009, 30(12):  1602-1606.  doi:10.3969/j.issn.1000-1093.2009.12.007

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For estimating electrostatic spark sensitivity of RDX-Al powder in the process of roller mix?ing, advanced charge method was taken to measure electrostatic spark sensitivities of RDX and RDX- Al, and chute method was applied to measuring electrostatic accumulations of RDX and RDX-A1 in the friction condition. The investigated results show that the max electrostatic energy of RDX is 0.013 J, and that of RDX-A1 is greater than 0.013 J at inexplosive condition; slipping in 1 m chute, the max-mum electrostatic accumulation of RDX is about - 3.0 -- 5.0 μC/kg, and max electrostatic energy is 1.41 X 10-3 J, which is less than E0 0.013 J, E50 0.288 J and E_ 0.577 J of RDX; the maxmum elec-trostatic accumulation of RDX-A1 is 1.2 μC/kg，by which the produced energy can not directly fire RDX-A1 explosive powder; after adding 3 % ?8 % petroleum ether and ethyl acetate, the maxmum electrostatic accumulation of RDX-A1 explosive is 1.50 μC/kg, which produces probably 1.23 X 10 —4 J spark energy, that is less than minmum ignition energy of petroleum ether and ethyl acetate.

Numerical Modeling on the Accelerated Aging of JB-9014 Explosive

GAO Da-yuan, HE Song-wei, ZHOU Jian-hua,LU Bin

2009, 30(12):  1607-1610.  doi:10.3969/j.issn.1000-1093.2009.12.008

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To understand the effect of aging on detonation performances of JB-9014 explosive, the ac?celerated aging mechanism and effect of JB-9014 explosive were analyzed. From the thermogravimetry (TG) curves of JB-9014 explosive under the heat rate of 5 K/min, 10 K/min and 20 K/min respec?tively, the thermal decomposition activation energy, pre-exponential factor, mechanism function and kinetic equation of JB-9014 explosive were deduced, by Ozawa’s equation and decomposition extents. Based on the derived kinetic equation, the density, composition and heat of formation to various de?composition extents of JB-9014 explosive were calculated at the accelerated aging temperatures of 70 and 75 °C , respectively. The detonation parameters of JB-9014 explosive were calculated by means of the VLWR code. The investigated results show that the detonation velocity and detonation pressure decrease with the decrease of the density after accelerated aging of JB-9014.

Study on Conditions and Preliminary Mechanism of TNT Biodegradation by the Strain S (Klebsiellasp.)

GUO Xiao-jie，XIN Bao-ping, CHEN Shi,GUO Lei, ZHANG Xian

2009, 30(12):  1611-1616.  doi:10.3969/j.issn.1000-1093.2009.12.009

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Conditions and preliminary mechanism of TNT biodegradation by the strain S were investi?gated .The results show that glucose addition greatly enhances the biodegradation of TNT by strain S, and the removal efficiency of TNT reaches 100% after 16 h culture; while the removal efficiency of TNT is only 12% without glucose addition, leading to S growth slightly; KNO3 addition also pro?motes TNT biodegradation, 100 % TNT removal is attained, more than the 80 % removal without KNO3 addition; the increase in TNT concentration has no evident adverse effect on its degradation, the strain S can completely biodegrade TNT even at 200 mg/L. The biodegradation of TNT involves that TNT is transformed into condensation product A and then A is degraded through ring cleavage. The existence of nitroreductase, toluene dioxygenase, catchpoll dioxygenase in the S biological catalyst system supplies enzyme basis for TNT degradation.

Multi-target Localization Using Multiple Input Multiple Output Radar Based on Receiving Diversity

CHEN Jin-li，GU Hong, SU Wei-min,LIU Bing-qi

2009, 30(12):  1617-1623.  doi:10.3969/j.issn.1000-1093.2009.12.010

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Aiming at the disadvantages of low positioning accuracy and target ghost generation in mul?tistatic radar with broad transmitting beam and broad receiving beam, multiple input multiple output (MIMO) radar based on receiving diversity was discussed. The MIMO radar is a special structure of single transmitting station and multiple receiving stations(STMR)-multistatic radar with broad trans?mitting beam and broad receiving beam, and can avoid the complicated beam scan synchronization. A scheme for multi-target localization with Capon space spectrum estimation algorithm using MIMO radar based on receiving diversity was proposed, and the positioning accuracy of the MIMO radar was compared with that of the STMR multistaic radar. The simulated results show that MIMO radar based on receiving diversity effectively solves the problems of low positioning accuracy and target ghost gen?eration in multistatic radar with broad transmitting beam and broad receiving beam.

Adaptive Polling MAC Protocol for Tactical Data Link System

WANG Wen-zheng, ZHOU Jing-lun, LUO Peng-cheng

2009, 30(12):  1624-1631.  doi:10.3969/j.issn.1000-1093.2009.12.011

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Considering the application background of tactical data link, an adaptive polling MAC proto?col (APMP) was proposed to overcome shortcomings such as low channel utilization ratio, being unable to meet the demand of real-time communication in emergency situations. With the bayesian-estima- tion-based polling scheduling algorithm, APMP can adaptively select the nodes with more high-priority packets to poll by a high selection index, to increase the channel utilization ratio and provide differenti?ated services. At the same time, APMP can adapt to the dynamic changes of network topology, and solve the empty polling problem caused by the node beyond scope of coverage of the network control station. The simulated results show that, compared with the existing centralized polling protocol of the typical tactical data link, APMP can use radio channel resources efficiently, and has good perfor?mance.

Design and Optimization of Hyper-chaotic Orthogonal Polyphase Code Signal

HU Ying-hui, GENG Xu-pu, DENG Yun-kai

2009, 30(12):  1632-1637.  doi:10.3969/j.issn.1000-1093.2009.12.012

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Orthogonal polyphase code signal plays a very important role in netted combat radar system and the electronic counter-countermeasures (ECCM) of synthetic aperture radar (SAR) . A new design scheme of generating the signal was proposed using hyper chaotic sequences. Based on the requirement of radar performance, some methods on optimizing the correlation properties of hyper chaotic sequences were introduced, in which that solving the maximal set of cross-correlation is a maximum clique prob?lem was pointed out for the first time and its simple but effective solving method was put forward. The simulated results show that the signal accords with independent identical distribution, has higher com?plexity than conventional chaotic sequences (larger than 1.2), and provides a large number of code se?quences, what’s more, the sidelobe level of it is 10 dB lower than that of Frank polyphase code after the coherent accumulation of pulses, which is suitable in netted radar system and ECCM environment.

Corrected Error of Base-plane for Vehicle-borne Photoelectric Theodolite

JIANG Wei-wei, GAO Yun-guo, FENG Dong-yan,CHEN Zhao-bing

2009, 30(12):  1638-1641.  doi:10.3969/j.issn.1000-1093.2009.12.013

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In order to improve the measure precision of the vehicle-borne photoelectric theodolite, the corrected method for measure error come from base-plane’s error was proposed. The error of base- plane based on base-plane’s structure of the theodolite was analyzed. The calculating formula of the baseplane’s obliguity and the biggest incline vector calculated by the measured obliquity come from horizontal sensors was deduced based on two vertical each other horizontal sensors fixed on the theodo?lite base. The measure error come from base-plane’s error was analyzed by spherical surface coordinate and its corrected formulas were given. The experimented results show that the method has better effi-ciency of correcting the measure error, in which the maximum corrected errors are 5' in azimuth and 2' in pitch.

Fast Parameter- Estimation of LFM Signal Based on Improved Combined WVD and Randomized Hough Transform

LIU Feng，SUN Da-peng, HUANG Yu, TAO Ran, WANG Yue

2009, 30(12):  1642-1646.  doi:10.3969/j.issn.1000-1093.2009.12.014

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In order to solve the problem of calculation and storage in traditional Hough transform and improve the computation speed and veracity in the LFM signal parameter estimation, the time-fre- quency character of single- component LFM signal with noise was obtained by Wigner-Ville distribution (WVD), the instantaneous frequency was estimated using a maximum value method; the parameter estimation was realized though randomized Hough transform (RHT) based on a section of the frequen-cy. The computed and analyzed results show that, compared with the traditional WVD-HT, WVD- RHT has lower computation load and better practicability, in which the computation time is about one third of WVD-HT, but the estimation precision is higher than WVD-HT.

Character Simulation Research on the Absorber for Stabilized Platform on the Armed Copter

HONG Hua-jie，WANG Xue-wu, YANG Guang, TAO Zhong

2009, 30(12):  1647-1652.  doi:10.3969/j.issn.1000-1093.2009.12.015

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Passive vibration reduction is a valid way to realize high stability accuracy of airborne plat?form. It was found that ingenious conception of absorber without angular displacement for stabilized platform on a certain armed copter realizes linear vibration isolation and uncoupling between the free degrees. The kinematic characters of the absorber were discussed, its dynamic model was set up by Lagrange equations; the coupling character between free degrees was analyzed based on the relational hypothesis, and the syntony frequencies of translational motion were calculated; the virtual prototype was built up and the simulated results by the virtual prototype consist with the analyzed ones theoreti-cally. The research is expected to provide references for domestic congener products.

Design of Micro-Displacement Amplifier of Piezoelectric Servo

YU Zhi-yuan, YAO Xiao-xian, DAI Run-zhi,WU Song-ping

2009, 30(12):  1653-1657.  doi:10.3969/j.issn.1000-1093.2009.12.016

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A design method of micro-displacement amplifier in a novel piezoelectric servo was proposed based on stiffness analysis of flexure hinges. Composition and operating principle of the servo was rep-resented, mathematic model of the servo was deduced, effects of the amplifier’s structural parameters on the servo’s performance were analyzed, and the design principle of flexure hinges was determined. Curves of the hinge stiffness ratios were obtained by analyzing stiffness characteristies of the five sin?gle-axis flexure hinges, parameter optimization design of the amplifier was performed by finite element analysis method. The simulated results show that the design method used for designing the amplifier is effective extremely.

Effect of Orifice Inclined Angle on Flow Control of the Stalled Airfoil with Synthetic Jet Actuator

ZHANG Pan-feng, WANG Jin-jun

2009, 30(12):  1658-1662.  doi:10.3969/j.issn.1000-1093.2009.12.017

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Numerical simulation on effect of orifice inclined angle on separation flow control of the stalled NACA0015 airfoil was carried out by the Reynolds averaged. Navier- Stocks equations solved with Fluent 6.1 at the high angle of attack (a = 20°), i. e. orifice inclined angle relative to synthetic jet actuator locates in recirculation region of the airfoil. The calculated results demonstrate that the op-timum orifice inclined angle is 30 degree for the synthetic jet controls the separated shear layer of the airfoil, which means the jet points to the stream-wise flow direction and is very close to the wall; at the inclined angle, lift coefficient of the airfoil increases by 5% compared with that with vertical jet flow control, meanwhile, drag coefficient of the airfoil decreases by 15% ? The mechanism of the en?hancement flow control effect at lower orifice inclined angle was also revealed by analyzing the vortex structure separated from the airfoil and the flow field near the actuator orifice.

Experiment Investigations on Normal Reflected Blast Wave near the Spherical Explosive

ZHANG De-zhi, LI Yan, WANG Deng-wang,WANG Chang-li, ZHONG Fang-ping, LIN Jun-de

2009, 30(12):  1663-1667.  doi:10.3969/j.issn.1000-1093.2009.12.018

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The accurate pressure and impulse of reflected blast wave are very significant for the design of explosive vessel which can contain large explosive. The pressure, impulse and shock travel time of normal reflected blast wave were obtained by means of experiments at the range of the scaled distance is 0.098?0.5 m/kg1/3. The experience equations of the pressure, the scaled impulse and the scaled shock travel time vs. the scaled distance were fitted respectirely with the data in this paper and the lit?eratures. The investigated results indicate that the pressure attenuates exponentially with the scaled distance increasing, the reflected impulse is directly proportional to the explosive equivalent and in?versely proportional to the square of the distance.

Reliability Analysis of Ship Deck Based on Slamming Loads

ZHANG Jing, SHI Xing-hua, XU Ding-hai, WANG Shan

2009, 30(12):  1668-1673.  doi:10.3969/j.issn.1000-1093.2009.12.019

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Considering the buckling failure modes of ship deck, a method of assessing the reliability of ship structure under slamming load was proposed. The random process model of deck failure function under the combining actions of slamming, wave-induced and Stillwater loads was set up based on the random process theory, considering the correlation of amplitudes of slamming and wave-induced loads. The reliability of the process was solved by up-crossing rate and parallel system reliability analysis method. The influences of damping, slamming rates and correlation coefficient of the loads on the reli?ability were analyzed through an example, the results indicate that the damping rate decides the influ?ence of slamming load on the reliability. The reliabilities of all primary failure modes were also calculat?ed, the results show that the stiffener tripping failure is the most dangerous. The method can provide theoretical foundation for evaluating the structural reliability of ship reasonably.

Cooperative Localization for Multi-UUVs Based on Time-of-flight of Acoustic Signal

ZHANG Li-chuan, LIU Ming-yong, XU De-min,YAN Wei-sheng

2009, 30(12):  1674-1678.  doi:10.3969/j.issn.1000-1093.2009.12.020

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The research on cooperative navigation and localization of multi-UU Vs is an important topic to solve the navigation problem in middle-depth-zone. An algorithm based on time of flight of acoustic signal for multi-UU Vs was presented. In the leader-fellow structure, the master UUV is equipped with high precision navigation system, and the slave UUV is equipped with low cost navigation sen?sors. They all are equipped with acoustic device to measure relative location. An extended Kalman fil?ter was designed, which fused the proprioceptive and exteroceptive sensors, to locate the slave UUV in real time. The researched results show that the navigation accuracy is improved effectively by using the cooperative navigation and localization method.

Storage Reliability Analysis of Explosive Initiator Using Time Series Model

HONG Dong-pao, ZHAO Yu

2009, 30(12):  1679-1683.  doi:10.3969/j.issn.1000-1093.2009.12.021

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The explosive initiator is one kind of sensitivity products with long life and high reliability. To improve precision of storage reliability analysis, the method of storage reliability analysis for explo?sive initiator was proposed using the time series model based on the character of pyrotechnics and its storage reliability and its sensitivity test data. In the method, the maximum likelihood estimations of sensitivity distribution parameter were obtained from the up-down test data, and the shrinkage estima?tion for scale parameter was obtained by combining the sample information with prior information. The simulated result shows that the shrinkage estimation is better under certain conditions. The time series models were used to describe the relation between the sensitivity distribution parameters and storage time. And the models were estimated by least square method with the distribution parameters estimations. Then the distribution parameters were predicted based on the models. The confidence in?terval of storage reliability was obtained with fiducial inference. The illustrative example shows that the method is reasonable and available for storage reliability analysis of the explosive initiator with high reliability.

Stability and Bifurcation of the Drilling Shaft System in Processing Deep Hole Based on Boring and Trepanning Association

KONG Ling-fei，LI Yan, Lü Yan-jun

2009, 30(12):  1684-1690.  doi:10.3969/j.issn.1000-1093.2009.12.022

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The stability and bifurcation of the drilling shaft system in processing deep hole based on boring and trepanning association were analyzed. Taking effects of the mass eccentricity and the cut?ting force fluctuating on the stability and bifurcation into account, nonlinear hydrodynamic force was adopted to increase the numerical accuracy. Based on the isoparametric finite element with eight node method, the nonlinear hydrodynamic force and their Jacobian matrices of compatible accuracy were cal?culated simultaneously. In the stability analysis, by changing the time scale, the period of the periodic orbit of the nonlinear drilling shaft system was drawn into the governing equation of the system explic?itly; the generalized shooting procedure was recompiled; the period took part into the iteration proce?dure of the shooting method as a parameter, and thus the periodic orbit and its period of the drilling shaft system were determined rapidly. Correctness and effectiveness of the proposed method were veri?fied by combining the theoretical computation with the experimented results based on the Floguet sta?bility theory.

An Algorithm of Determining Fixturing Parameters for the Complex Workpiece

QIN Guo-hua, LU Dong, WU Tie-jun

2009, 30(12):  1691-1697.  doi:10.3969/j.issn.1000-1093.2009.12.023

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The fixturing for complex workpieces is a difficult problem in the mechanical manufacturing field. The determination of workpiece fixturing has still depended, on the designer’s experiences and expert’s knowledge which is difficult in satisfying the high-precision machining requirement of the complex workpiece. Therefore, an algorithm to fixturing parameter determination was proposed for the first time. On the basis of the velocity composition law of a particle movement and solution charac?teristic of homogeneous linear equations, the approach to verify the locating correctness was established to figure out the feasible number and layout of locating points; in light of the static equilibrium condi?tion and solution existence of homogeneous linear equations, the machining stability model and its solu?tion technology were formulated to optimize the magnitude, placement and application sequence of clamping forces. In addition to the verification of the fixture feasibility, the proposed method can be used for the determination of fixturing parameters.

Study on Low-frequency Vibration Reaming of Panzer Pedrail

KONG Fan-xia, WU Ji-liang, ZHANG De-yuan,WANG Sheng-yu

2009, 30(12):  1698-1701.  doi:10.3969/j.issn.1000-1093.2009.12.024

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Low-frequency vibration reaming ( LFVR) with “ cutting-separating-cutting-separating” pulsant action has rectification effect and improves the straightness; the characters of LFVR, involving pulsant cutting, micro-cutting, repeated pressing and disconnection chip, can improve the surface quality of holes. The reaming experiments on panzer pedrails plates were carried out and comparisons of straightnesses and surface qualities between the reaming with LFVR and the conventional were per-formed under the same conditions. The experimented results show that the straightness improves by one level and the surface roughness enhances by two levels compared to the conventional reaming.

Study on the Instantaneous Radiation Optical Fiber Pyrometer

WANG Xiang, HUANG Yi-min, HAN Yong, LU Xiao-jun

2009, 30(12):  1702-1705.  doi:10.3969/j.issn.1000-1093.2009.12.025

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In order to measure accurately the detonation temperature and study up the detonation char?acteristic of high explosive, a new instantaneous radiation optical fiber pyrometer was developed, which divides one band of target light into six bands by the optical fiber beam splitter, to guarantee that light signal of each channel of the pyrometer comes from the same point of target light and im?prove the accuracy of temperature measurement. The method and the principle with an optical fiber pyrometer were given. Taking TATB base explosive as an example, its detonation spectra were mea-sured .The detonation temperature of TATB base explosive is 3 135 K ± 28 K by means of the least square method.

Research on Vehicle Assignment Model for Constraints Handling Based on Computational Intelligence Algorithms

PAN Feng, CHEN Jie, REN Zhi-ping,WANG Guang-hui

2009, 30(12):  1706-1713.  doi:10.3969/j.issn.1000-1093.2009.12.026

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The task allocation of unmanned aerial vehicle (UAV) is a complex assignment problem with various constraints. With the increase of the size of scenarios and the number of constraints, UAV assignment problems become more complicated. Especially, the potential dimensional explosion and optimization difficulty are unavoidable to those algorithms based on linear programming. A new UAV assignment model was proposed, which transforms the UAV assignment problem into a multi- constraint optimization problem. The proposed model reduces the dimension of solution space effective?ly, improves the optimization efficiency, and is adapted to the other computational intelligence algo?rithms .Several computational intelligence algorithms, such as particle swarm optimization, genetic al?gorithm, differential evolution algorithm, clonal selection algorithm, were applied to accomplish the optimization work. Numerical experimented results illustrate that the model has better adaptability and extensibility, can solve complex UAV assignment problems combined with the computational intelli?gence algorithms.

Study on Measurement Method for Small Bottom Gap of Ammunition by Industrial CT Imaging

LU Yan-ping, WANG Jue, YU Hong-lin

2009, 30(12):  1714-1717.  doi:10.3969/j.issn.1000-1093.2009.12.027

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In the non-destructive testing for some ammunition, the precise measurement for small bot?tom gap is one of the main techniques to ensure their quality. A measurement method for thickness of the small bottom gap was proposed by volume effect of the CT imaging dexterously. The position where a gap exists was scanned by industrial CT at a set scanning thickness, in which the gap is con?tained in the scanning range; the gray difference was transferred into density difference by the CT im?age; the thickness of the gap was calculated by densities of the material and the air in the gap. The measured result shows that the method can be applied to the gap with thickness from 0.3 mm to 2.0 mm, the maximal absolute error is less than 0.030 mm and the relative error is less than 4.8%. The proposed method solves the problem of measurement for the gap, and satisfies the requirement of non?destructive testing and evaluating for products.

Effect of Multi-component Active Fluxes on Penetration in TIG Welding

SONG Tian-ge, ZHANG An

2009, 30(12):  1718-1721.  doi:10.3969/j.issn.1000-1093.2009.12.028

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Based on uniform mixture experimental design, the regression model was set up and the Si02-Mg〇-Ti〇2_Cr203 system multi-component active fluxes were investigated. The effects of active flux components on weld penetration of low alloy high strength steel in tungsten inert gas (TIG) weld?ing were discussed, the regression equation of penetration with active flux components was developed, and the complex inherent relation between active flux components and penetration was revealed. The results show that the interactions between MgO and Cr2〇3，MgO and Ti〇2, Cr2〇3 and Ti〇2 increase the weld penetration; the penetration of welding bead coated with the active flux A haring the best mixture proportion is 2.3 times as much as that without it, under the same welding technological pa?rameters; the fused layer with weak conductance formed, by SiO2, Cr2O3，MgO on anodic surface of the basic material makes arc conductive path long, arc contracted, and penetration increased.

Research on Vehicle Fault Diagnosis Method Based on Improved Negative Selection Algorithm

MENG Qing-hua，ZHAO Wen-li, FAN Zhi-hua,ZENG Fu

2009, 30(12):  1722-1726.  doi:10.3969/j.issn.1000-1093.2009.12.029

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According to the negative selection algorithm in existance, an improved negative selection al?gorithm which adapts to vehicle online testing was presented. The methods of coding data string, cre?ating self sets and determining number of detectors in the improved negative selection algorithm were analyzed. The detected results by the noise data of normal and fault non-slipping differential used in a certain military vehicle show that the improved, algorithm is effective and more accurate compared with the neural network testing method.

Simultaneous Localization and Mapping of Robot Concerning Statistical Property Mutation

YI Ying-min, LIU Ding

2009, 30(12):  1727-1732.  doi:10.3969/j.issn.1000-1093.2009.12.030

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To deal with the problem concerning the statistical property mutation of a system in the un?known environment, a simultaneous localization and mapping (SLAM) algorithm based on non-linear interacting multiple model (IMM) was proposed. It is main idea of the algorithm that non-linear Gaussian model is used to approximate non-linear and non-Gaussian model ; the extended Kalman filter (EKF) algorithm is employed to linearize the non-linear system for each model; the non-linear IMM algorithm is used to get fusion estimated value in each step; SLAM of the robot can be achieved. The Monte Carlo simulation results show that at changing RMSEs of noises of process, observation and both mentioned, the proposed algorithm has better estimate precision compared with EKF-SLAM al?gorithm and Fast-SLAM algorithm.

Research Notes

Study on Robust Reconfigural Flight Control Law Based on Simple Adaptive Control

Ql Xiao-hui，YANG Zhi-jun, WU Xiao-bei

2009, 30(12):  1733-1737.  doi:10.3969/j.issn.1000-1093.2009.12.031

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A design method of reconfigural flight control law was presented based on simple adaptive control for improving robustness and anti-jamming capability of the system. The reconfigural flight controller contains a basic feedback controller and a simple adaptive controller for the fault flight con-trol system; the linear quadratic optimal control with scheduled stability was applied to basic controller for improving stability of the system; the parallel feedforward compensator was introduced into simple adaptive controller to make the system meet demand of positive realness, and transformed into stabiliz- able problem synchronously which is solved by utilizing YALMIP toolbox. Taking the lateral flight control system of a certain aircraft as an example, aiming at the case of parameter variation and bound?ary disturbance in the system, the simulation was performed by the proposed method. The simulated results show that the system has better robustness and adaptability at tracking reference input signal.

Detection of Line Spectrum of Fundamental Frequency on Shaft-Rate Electric Field of a Ship

LI Song, ZHANG Chun-hua，LUAN Jing-de

2009, 30(12):  1738-1742.  doi:10.3969/j.issn.1000-1093.2009.12.032

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Shaft-rate electric field is one of the physical fields caused by navigating ships. Its funda?mental frequency is the rate of propeller rotation and it has stable line spectrum. In order to acquire the line spectrum of fundamental frequency, continuous spectra and the unacceptable frequency points were ruled out, the remainders were verified by the fuzzy model; according to the credible degree of the shaft-rate frequency, the fundamental frequency was acquired. The proposed method used for detect?ing fundamental frequency line spectrum of the shaft-rate electrical field gains better effectiveness.

Research on the Novel Generating and Transmiting Techniques of High Power Electromagenatic Impulse

HOU Lin, SONG Yao-liang, XIE Zhong-yuan，HAO Ming

2009, 30(12):  1743-1747.  doi:10.3969/j.issn.1000-1093.2009.12.033

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High power electromagnetic impulse generating is a technology with wide applications in geophysical research, geologic exploration, petroleum recovery, ECCM and microwave weapon area. Based on traditional MHD system and modern MHD, the high power impulse forming and transmit?ting technique was discussed, the transform technique and implementing circuits of the high power multiple impulses from the single low voltage impulse was investigated, the experimental result was given and the key implementing the system was expounded.

Research on High Precision Measurement of Centroid

LU Zhi-hui, SUN Zhi-yang, LI Xiang-yun,BO Yue, ZHANG Lei-le

2009, 30(12):  1748-1752.  doi:10.3969/j.issn.1000-1093.2009.12.034

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The measurement of centroid is very important for aircrafts, and higher measurement preci?sion is needed for the development of new weapons. With the combination of rotational axis, tradition?al balance and sensor technology, a new measurement mechanism of centroid was designed and a new measurement method was put forward, which can improve the measurement accuracy obviously. The structure, the measurement principle and method were presented and the measurement error was also analyzed theoretically, in which the maximum error of theoretical estimating is 0.023 mm for the de?veloped mechanism. The actual maximum measurement error for a standard sample is 0.02 mm, which is very close to the theoretical value. The experimented results show that the measurement pre?cision of this mechanism is very high. Using the mechanism and method proposed, a series of measure?ment equipments were developed and used in related fields.

Numerical Simulations on Impact Response of the Support of Gas Generator

JIN Qian-kun, CHEN Liu-tao

2009, 30(12):  1753-1756.  doi:10.3969/j.issn.1000-1093.2009.12.035

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It is important for dynamic response analysis and parameter design to understand the shock environment of the support of gas generator. Numerical simulations for impact experiments of the sup?port were investigated, and dynamic material parameters of the support were calibrated by use of LS- DYNA. Numerical calculations for parameters of loading properties were finished and validated by re?sults of the actual trial run, which gets the peak value of pressure impulse. Numerical predictions for impact deformation of three types of the support under the validated pressure loadings were carried out. The improved design was presented to supply important references for parameter designs and practical tests of the support.