Table of Content

30 June 2010, Volume 31 Issue 6

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Paper

Multi-dimensional Simulation for Optimization Matching of Intake Swirl and Combustion Chamber in Diesel Engine

ZHAO Peng， LI Guo-xiu， YU Yu-song

2010, 31(6):  657-662.  doi:10.3969/j.issn.1000-1093.2010.06.001

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In order to obtain matching relationship among intake swirl, combustion chamber's calibre ratio and shape, optimization matching of intake swirl and combustion chamber geometry was studied by using three-dimensional CFD software. The matching relationship that effects air flow and mixture formation in diesel engine was analyzed also. The results show that the optimization matching of intake swirl and combustion chamber can significantly improve power performance. The optimal matching swirl ratio increases with the increase of calibre ratio. For the calibre ratio of 0.8, the indicated power is the highest. The intake swirl influences the fuel vapor distribution near the combustion chamber wall surface, after fuel spray impingement. If the fuel spray does not impinge, the intake swirl will influence the interference of adjoining sprays and the space distribution of fuel vapor. It should be matched with various combustion chamber geometries properly. The matching swirl ratio is maximum for the reentrant combustion chambers and the power performance is optimal. The flow field in the fuel vapor region is strengthened with the increase of swirl ratio. It can promote the fuel atomization and combustion.

Simulation of Steering Characteristic for Hydrostatic Drive Tracked Vehicle

YANG Lei, MA Biao₁, LI He-yan₁, CHEN Bao-rui₁

2010, 31(6):  663-668.  doi:10.3969/j.issn.1000-1093.2010.06.002

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To analyze the steering dynamic characteristic of a hydrostatic drive tracked vehicle exactly, a steering dynamic system model was developed by using Matlab/Simulink on the basis of analyzing the fundamental steering theory of the hydrostatic drive tracked vehicle. The simulations of three steering conditions including medium radius steering, small radius steering and transition state steering, were performed. The allowable maximum speeds in these three conditions are obtained. The simulation results show that the variation of the speed has a significant effect on the system pressure.

Thermal Stress Analysis for Shell-chamber System Subjected to Pressure Load and Temperature Field

WANG Yong-juan₁, ZHAO Jun₂, TANG Zhu-xiu₁

2010, 31(6):  669-673.  doi:10.3969/j.issn.1000-1093.2010.06.003

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For the thermal effect, a mathematics model and a physics model for the shell-chamber system of a small caliber weapon, were built to consider the influence of the thermal and pressure based on the heated process in the system and the theories of elastic, plasticity and contact. The nonlinear finite element and the element Plane 13 of coupling thermal and structure in ANSYS were used in numerical simulation. The temperature loading process of propellant gas, the characteristics of the thermal stress is obtained when the transient heat and pressure loads act on the shell-chamber system simultaneously. The simulation results show that the thermal influence can not be ignored for the shell-chamber system.

Experimental Research on Semiconductor Bridge Ignition for LTNR

FENG Hong-yan, ZHU Shun-guan, ZHANG Lin, LI Yan, SHEN Rui-qi

2010, 31(6):  674-677.  doi:10.3969/j.issn.1000-1093.2010.06.004

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The ignition mechanism of the Semiconductor Bridge (SCB) ignition for LTNR was studied by comparing the effects of the firing voltage, capacitance and integral energy on the ignition time. The curves of voltage, current of the SCB and the appearing time of the second current peak under the same ignition condition were analyzed also. The results indicate that a critical function time exists for a given ignition circuit and it is affected by the forming time of the plasma. Two different ignition mechanisms are found. They show that the LTNR is ignited by plasma generated by SCB at high firing voltage and by Joule heat at low firing voltage for a given capacitor.

Small Infrared Target Detection Based on Least Squares Support Vector Machine Temporal Background Prediction

WU Yi-quan, LUO Zi-juan

2010, 31(6):  678-684.  doi:10.3969/j.issn.1000-1093.2010.06.005

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Aiming at suppressing the influence of natural background on the target detection effectively in lower signal-to-noise ratio, a method of small target detection in infrared image sequence was proposed based on the least squares support vector machine (LS-SVM) temporal background predication. Firstly, the gray value sequences at the same pixel locations in the previous frames were fitted by using the LS-SVM optimized by the particle swarm. The gray value at the same pixel location in the next frame could be predicted by the fitted function. Then, the estimated image subtracted from the source image gave the residual image. The residual image was segmented by using two-dimensional Tsallis-Havrda-Charvat's entropy threshold method. The real small target was confirmed by the continuity and consistency of its movement. The experimental results were given and analyzed. They were compared with those of the existing method of spatial or temporal background predication. The results show that the proposed method can precisely detect the small infrared target and it is superior to the existing method.

Optimal Control of Spatial Interconnected Systems

LI Hui, WU Qing-he

2010, 31(6):  685-691.  doi:10.3969/j.issn.1000-1093.2010.06.006

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This paper investigates the optimal control of spatial interconnected systems

Parameters Design of Stepped Frequency Signal Without Motion Compensation for Low Velocity Targets

YANG Yan-li, DENG Jia-hao, WU Cai-peng

2010, 31(6):  692-696.  doi:10.3969/j.issn.1000-1093.2010.06.007

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Frequency stepping waveforms can be used to obtain high range resolution. However, it needs to perform motion compensation. The influence of velocity and acceleration on one-dimension range profiles was analyzed. And the discrete peak error caused by inverse discrete Fourier transform (IDFT) was discussed in detail. Then, the factors that influence on velocity and acceleration without compensation were obtained. Based on analysis of the contradictions among high range resolution, bandwidth and maximal velocity without compensation, the velocity without compensation can be maximized through proper selection of parameters of stepped frequency signal. The simulation results show that the ranging without motion compensation for low velocity and short range targets is feasible.

Radar Target Recognition Based on Kernel Principle Component Analysis Reconstruction

ZHU Jie-hao， ZHOU Jian-jiang, WANG Fei, WU Jie

2010, 31(6):  697-702.  doi:10.3969/j.issn.1000-1093.2010.06.008

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Aiming at the target’s electromagnetism scatter characteristic mismatch problem

Research on Underwater Multiple Access Based on Acoustic Shielding

HUI Jun-ying₁， WANG Da-yu₁， ZHANG Guang-pu₁， YIN Jing-wei₁, WANG Xiao-lin₂

2010, 31(6):  703-709.  doi:10.3969/j.issn.1000-1093.2010.06.009

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Aiming at multiple address interferences existing in multi-user communication, this paper proposes a method based on the acoustic shielding. It utilized the difference in multi-path between sources and receiving array to realize the multiple address access. After the received signal is shielded and focused, the multiple address interferences will be suppressed significantly and the energy of sources will be enhanced. Therefore, the negative effects caused by the multi-path can be decreased obviously. The acoustic shielding can be combined with OFDM to design OFDM multi-user communication system, which can realize the multi-user communication without occupying extra bandwidth. The simulation results and analyses indicate that the acoustic shielding can not only mitigate the multiple address interferences, but also focus the desired signals, thereby, improve the system's throughout and bit error ratio. Moreover, the acoustic shielding allows the synchronous communication with various users in the same direction.

Research on Characteristics and Suppression of Fluctuation Noise Disturbance of Accelerative Propeller

FENG Yuan， TAO Ran

2010, 31(6):  710-715.  doi:10.3969/j.issn.1000-1093.2010.06.010

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For the hydro-acoustic seekers and intelligent hydro-acoustic fuses, extraction of acceleration and deceleration feature of propeller is a practicable way to detect and classify the maneuvering targets in a port region. The signal characteristics of fluctuating volume rediation noise, fluctuating rediation force noise and continuous spectrum noise of the cavitation produced by the accelerative propeller are analyzed in this paper first, and then the received signal model for the passive sonar is presented. To resolve the disturbance problem under certain signal processing condition, a fractional domain disturbance rejection algorithm is proposed, and its realization procedure is given also. In addition, the analysis result for the test data in cavitation tunnel, validates the feasibility of the proposed algorithm.

Research on Design of a Novel Electrode

CHEN Hao, CHEN Ju-qiu, HU Jun-bo

2010, 31(6):  716-720.  doi:10.3969/j.issn.1000-1093.2010.06.011

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The problems of outdated electrode were investigated and analyzed. A design scheme integrating conductor and cable was proposed. The numerical calculations were performed for the novel and outdated electrodes. According to the requirements that the novel electrode's contact resistance must be less than the medieval one's and buoyancy balance must be achieved, the design parameters can be determined. Then, the electrode's prototype was made based on the parameters and its scaling experiment is done. After performance evaluation and analysis for the novel electrode, it can be seen that the electrode is better than the outdated electrodes in the electric-field distribution and corrosion stability.

A Method for Obtaining Invariant Feature of Magnetic Flux Leakage Signals

LEI Liang-jin, WANG Chang-long, JI Feng-zhu, ZUO Xian-zhang

2010, 31(6):  721-724.  doi:10.3969/j.issn.1000-1093.2010.06.012

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To improve the defect reconstruction precision of magnetic leakage flux, a method to extract the invariant feature of leakage flux signals was proposed based on radial basis function（RBF）, analyzed the velocity's influence in the leakage flux inspection, and established 2-D finite element model, the method acquires the leakage flux signals in different velocities, takes the signals with velocity influence as the input of RBF network, and the static leakage signal as the output, to train the network. The experiment results show that it can compensate the velocity effect and extract the invariant feature of leakage flux signal precisely and effectively.

Dynamic Constitutive Relations and Dynamic Fracture of Ductile Materials under Impact/shock Loading

CHEN Da-nian， WU Shan-xing， WANG Huan-ran， MA Dong-fang， JIA Cun-wei，

2010, 31(6):  725-734.  doi:10.3969/j.issn.1000-1093.2010.06.013

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Assumed Y/G=constant and G/B=constant, seven constitutive models for the

Incremental Solution of Membrane Action on RC Beam-slabs Subjected to Severe Dynamic Load

CHEN Li, FANG Qin, GUO Zhi-kun

2010, 31(6):  735-740.  doi:10.3969/j.issn.1000-1093.2010.06.014

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To investigate the compressive membrane action of the reinforced concrete struct

Simulation of Concrete Dynamic Fracture

LIU Lu-guang, OU Zhuo-cheng, DUAN Zhuo-ping, LIU Yan， HUANG Feng-lei

2010, 31(6):  741-745.  doi:10.3969/j.issn.1000-1093.2010.06.015

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Under dynamic tensile loadings, the fracture strength of concrete increases with

Determining Failure Surface Parameters of the Johnson-Holmquist Concrete Constitutive Model

XIONG Yi-bo₁， HU Yong-le₁， XU Jin₂， CHEN Jian-jie₁

2010, 31(6):  746-751.  doi:10.3969/j.issn.1000-1093.2010.06.016

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In order to rationally determine the parameters in the Johnson-Holmquist (JH) c

Preparation and Wave Absorbing Properties of Surface-modified Micro-spheres

TAN Ye-fa, LI Li-guang, JIANG Guo-liang, CAI Bin, CHU Wei-jun

2010, 31(6):  752-758.  doi:10.3969/j.issn.1000-1093.2010.06.017

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In order to develop low density, low cost and high efficiency absorbing materials, the liquid phase hydrogen reduction under high pressure was used to modify the micro-spheres, and the surface-modified micro-spheres coatings were prepared. The test results show that the nickel particles on the surface of the micro-spheres are homogeneously crystallized and the cladding is complete gradually with the increase of nickel plating. The absorbing properties of the surface-modified micro-spheres coatings in the frequency range from 8 to 18 GHz were measured. The influences of mass fraction of nickel, particle content and thickness on the absorbing properties of the coatings were studied. The research results show that the modified micro-spheres coating with 50% nickel plating, 65% particles and 3 mm in thickness exhibit better wave absorbing property. The minimum reflectivity is -14.555 dB in the frequency of 9.817 GHz, the bandwidth for -10 dB is 3.1 GHz.

Reliability Sensitivity Sequencing of Rotor System with Oil Whip Fault

SU Chang-qing₁, ZHANG Yi-min₂, GOU Li-jie₃， DU Jin-song₁

2010, 31(6):  759-764.  doi:10.3969/j.issn.1000-1093.2010.06.018

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Based on the regularity and the characteristics of the oil whip, the reliability problem of the rotor system was studied by using the random perturbation and fourth moment technologies theoretically. Combined with the sensitivity technology, a reliability sensitivity analysis method for avoiding oil whip in rotor system was proposed. The variation rules of reliability sensitivity were obtained and the effects of design parameters on the reliability of rotor system were discussed. The contribution rates of the random parameters to the reliability of rotor system were discussed also. The method presented in this paper provides a theoretic basis for the optimization design of rotor system.

Design Optimization for Structural Fatigue Reliability Based on Artificial Neural Network

MENG Guang-wei, SHA Li-rong, LI Feng, LI Guang-bo

2010, 31(6):  765-769.  doi:10.3969/j.issn.1000-1093.2010.06.019

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The applications of artificial neural network (ANN) method in the analysis of fatigue reliability and design optimization for structure were studied. As the relationship between the structural fatigue life and its influence factors is highly complex and nonlinear, it is difficult to calculate the fatigue reliability with the traditional methods. The ANN response method was adopted to simulate the limit state function of the structure and its derivatives to calculate its reliability. The ANN was also used to design the structure optimally based on the reliability analysis results. A numerical example shows that the method is feasible and applicable.

Experimental Technique and Analysis

Electro-hydraulic High Frequency Fatigue Test System

JIA Wen-ang, RUAN Jian, LI Sheng, PEI Xiang, YU Zhe-qing, ZHU Fa-ming

2010, 31(6):  770-775.  doi:10.3969/j.issn.1000-1093.2010.06.020

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The working frequency of the electrohydraulic vibration exciters in conventional fatigue test system is limited to fairly narrow range by the frequency response capability of the servo valve. A novel system of electrohydraulic vibration exciter using a 2D valve (two-dimensional control valve) to control a hydraulic actuator is therefore proposed to enhance frequency response capability, including 2D valve, cylinder and bias control servo valve. In the 2D valve, the rotary and sliding motions are independently exploited to control the frequency and the magnitude of the vibration respectively. The frequency of the 2D valve controlled vibration exciter is determined by the rotary speed. By adjusting this factor in the 2D valve design, the proposed scheme of vibration exciter is apt to realize high-frequency vibration and to increase the working frequency of fatigue test system. The theoretical analysis and experimental verification are carried out in this paper. The results show that the simulation waveforms basically coincide with the experimental results, the tested object can be excited synchronously within the frequency 5~200 Hz, and the frequency and amplitude can be controlled continuously. The system has been applied in practice.

Experimental Study on Impact Performance of Hybrid Fibers Reinforced Light-weight Aggregate Concrete

WU Ping-an, LIU Yi-ping, GAO Ming-liang, YANG Jie, LIU Shou

2010, 31(6):  776-781.  doi:10.3969/j.issn.1000-1093.2010.06.021

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To study the impact dynamic performance of high strength hybrid fibers reinforce

Research Notes

Research on Topology Optimization of Power Train Bracket under Multiple Loads

RUI Qiang, WANG Hong-yan, WANG Liang-xi

2010, 31(6):  782-786.  doi:10.3969/j.issn.1000-1093.2010.06.022

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In order to use the optimization method in the structure design of a power train bracket, a topology optimization based on density variables method was studied. In the optimization, the minimum combined compliance index considering multiple frequencies and static load conditions was taken as an objective function, and the fraction of design volume as the constraint. It can be found that the stiffness, strength and modal performance of the optimized bracket are improved tremendously after optimization, the maximal stress reduces from 954 MPa to 207 MPa, and the natural frequency of the first modal increases from 48.5 Hz to 141 Hz. The results show that the topology optimization method is an effective method of structure design for the power train bracket.

Evaluation of Operational Effectiveness for Truck-mounted Howitzer

JING Yao-jie, YANG Xiao-ping₁, LIU Yu-wen₃, HOU Ming₃

2010, 31(6):  787-790.  doi:10.3969/j.issn.1000-1093.2010.06.023

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The operational effectiveness of the truck-mounted howitzer is divided into fir

Target Location for Passive Radar in Single Frequency Network

GAO Zhi-wen， TAO Ran₂， WANG Yue₂

2010, 31(6):  791-795.  doi:10.3969/j.issn.1000-1093.2010.06.024

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A target detection model for DTTB-based passive radar in a singl

Study on Applicability of Analytical MGB Model of Evaporation Duct

TIAN Bin₁， CHA Hao₁， ZHOU Mo₁， SONG Wei₁， ZHANG Ning₂

2010, 31(6):  796-801.  doi:10.3969/j.issn.1000-1093.2010.06.025

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The basic principle of the analytical MGB evaporation duct model proposed by French scholars is described in this paper. The effects of air temperature, sea temperature, relative humidity, wind speed and air pressure on the evaporation duct's height of the model is analyzed through numerical simulation. Then, the duct height is taken as a criterion, and the applicability of the analytical MGB model in experimental sea areas is studied by using the measured duct height data and meteorological information at the reference altitude during recent years. The results show that the model can predict the duct height exactly in near-neutral conditions.

Vague Set Method for Uncertain Multi-sensor Object Recognition

WAN Shu-ping

2010, 31(6):  802-806.  doi:10.3969/j.issn.1000-1093.2010.06.026

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To solve the application problem of Vague set theory in multi-sensor data fusion, a new method for uncertain multi-sensor object recognition was proposed. The model for multi-sensor object recognition system was accurately constructed based on Vague set definition. An object recognition method combined Vague set with optimal membership was presented. It defines the distance between two Vague sets. By solving the bi-objective programming model, the weights of sensors can be determined objectively to avoid the subjectivity in selecting sensors' weights. This model can be used to obtain the optimal membership of each object. The best object is determined by the optimal membership then. A simulation example shows the method's effectiveness and creditability.

A New Parameter Design Method for 3rd-order Range Tracking Loop

CUI Wei, ZHU Xin-guo, SHEN Qing

2010, 31(6):  807-810.  doi:10.3969/j.issn.1000-1093.2010.06.027

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Aiming at the range tracking for highly maneuvering targets, a new parameter design method is proposed for 3rd-order range tracking loop based on α-β-γ tracker. First, it determines the loop bandwidth according to the least range error criteria, which is used to fit 3rd-order pole of the loop's transfer function under critical damping state. Then, the parameters α, β and γ are calculated according to the 3rd-order pole. The simulation results show that the error between theoretical value and fitted value with 6th-order polynomial is less than 10^-4. Finally, the tracking accuracy of 3rd-order range tracking loop is analyzed. Furthermore, a new calculation method of optimal bandwidth according to the least range criteria is proposed.

A Path Compression Technique Based on Dynamic Model in Ad-hoc Demand Routing Protocols

XU Jia₁, LI Qian-mu₂, WANG Yong-li₂, LIU Feng-yu₂

2010, 31(6):  811-819.  doi:10.3969/j.issn.1000-1093.2010.06.028

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The path compression techniques are efficient demand routing optimizing technique for mobile Ad Hoc networks. However, the current path compression techniques have some shortages, such as blindness for compression, unstable path, frequent ephemeral short-cuts and multiple short-cuts etc. This paper establishes a dynamic path compression model and calculates the dynamic, real-time stable compression period in probability sense. A dynamic model-based path compression technique (DMPCT) is proposed, which can restrain the blindness for path compression efficiently, lessen the ephemeral short-cuts and multiple short-cuts and improve the path stability obviously. The simulation results show that DMPCT achieves low original RREQ, low control overload, low end-to-end delay and high delivery rate compared with both AODV and PCA. It is an efficient, stable path compression technique for demand Ad Hoc routing.

Avoiding Preemption MPLS DS-TE Routing Algorithm

DU Li, LIN Xiao, HUANG Jun， LI Hai-tao

2010, 31(6):  820-824.  doi:10.3969/j.issn.1000-1093.2010.06.029

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Currently, most of main algorithms for traffic engineering can not overcome the impacts on different types of traffic flow sequence and bandwidth ratio, and seldomly consider the issue of avoiding LSP preempting when calculating the routing for the traffic request. This paper proposes an MPLS DS-TE routing algorithm PA-DTE（Preempting Algorithm-DiffServ aware Traffic Engineering） to avoid preemption. It takes the bandwidth ratio of all types of traffic flow into account and gives priority to the free link, thereby, reduces the number of the preempted LSP. To validate its performance, the algorithm is implemented on the simulation platform NS2. The simulation results show that the new algorithm does well in balancing load, maintaining proportions of each CT service in each link, ensuring QoS of network and avoiding preemption, etc., compared with the algorithms which do not consider the issue of avoiding LSP preemption.

A Synchronization Method of TDDM Spread Spectrum Frequency and BOC Modulation Signal

LIU Fang, FENG Yong-xin₁, PAN Cheng-sheng₂

2010, 31(6):  825-831.  doi:10.3969/j.issn.1000-1093.2010.06.030

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Currently, the better synchronization receiving solution of time division data m

Mechanism Analysis and Prevention of Overflow-type Web Page Malicious Code

LI Zhi-yong, TAO Ran, WANG Yue, ZHANG Hao

2010, 31(6):  832-836.  doi:10.3969/j.issn.1000-1093.2010.06.031

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The overflow-type web page malicious codes can activate malicious codes by using the overflow vulnerability of the programmes in the users' host computers, which will harm the Internet users greatly. In order to study their mechanisms, this paper analyzes the typical overflow script and track their operation changes in RAM, finds out the specific details and conditions required for activating overflow-type web page malicious codes, analyzes their general design principle, and obtains their general design method of triggering a vulnerability in the operating system software. Finally, some suggestions to prevent the overflow-type web page malicious codes are presented.

Open-loop PD-Type Iterative Learning Control for a Class of Nonlinear Systems with Control Delay and Arbitrary Initial Value

SUN Yu , LI Zhi-an₁, LIN Hui₂

2010, 31(6):  837-841.  doi:10.3969/j.issn.1000-1093.2010.06.032

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In the iterative learning control theory, the common initial condition is that the iterative initial value is fixed or consistent with the desired initial value. The convergence condition of the open-loop PD-type iterative learning control for a class of nonlinear time-varying systems with control delay and arbitrary initial value is studied. The control input and the initial value learning simultaneously is used in the iterative learning, and the control input signal is given in advance. The algorithm solves the problem of control delay and initial value. The convergence of the learning algorithm is proved by using the operator theory. A simulation example of batch nonlinear control delay processes is given also. The research results illustrate the effectiveness of the algorithm.

Comparison and Post-processing Algorithm for 7 DOF Fiber Placement Machine

FU Hong-ya, SHAO Zhong-xi, LU Hua, LIU Yuan

2010, 31(6):  842-848.  doi:10.3969/j.issn.1000-1093.2010.06.033

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In order to make 7 DOF fiber placement machine to move along the planned path, the post-processing algorithm must be studied. By analyzing various inverse solutions of 7 DOF redundant robots and the process of fiber placement, a pose-separated method is adopted in the post-processing. In this method, the seven joints are divided into two parts, the principle joints and the mechanical arm. The post-processing keeps the mechanism's redundancy, avoids the kinetic analysis and optimization, and simplifies the calculation. By analyzing different processing methods for the principle joints, both post-processing method based on the motion trajectory of the end of mechanical arms and post-processing method based on the pressure direction at the trajectory point are proposed. Compared above methods, it can be found that the latter method can make the motion of machine tools smooth, the ranges of joints small, the fluctuation of joint angles small. The post-processing method and pose-separated method are all verified by the placement simulation.

Dynamic Modeling of Mobile Manipulator Based on Screw Theory

WANG Hong-qi, WANG Tai-hua

2010, 31(6):  849-854.  doi:10.3969/j.issn.1000-1093.2010.06.034

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The screw theory can be easily used to build up the dynamic model of a base-fixed open-chain or closed-chain robot, however, for the mobile manipulators, its application is worth exploring. Based on the screw theory, a method of the dynamics modeling for the mobile manipulator is proposed. First, by constructing virtual links, the mobile manipulator can be transformed into an equivalent base-fixed open-chain robot composed by joints with single degree of freedom. Then, by applying exponential product formula of rigid screw, the kinetic constraint equations of mobile platform can be derived, and, by building Jacobin matrix of each rigid body, both rigid bodies' and the whole systems' kinetic energy can be found out. Finally, the dynamic model of mobile manipulator can be built up based on Lagrange-d′Alemertprinciple.

Parameter Identification for Friction Model for Hydraulic Simulator Based on Optimization

GUO Jing, YANG Ji-zhi, LIU Rui-min

2010, 31(6):  855-859.  doi:10.3969/j.issn.1000-1093.2010.06.035

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Aiming at inaccurate identification for nonlinear dynamic friction parameters in hydraulic simulator, this paper presents an optimization algorithm used in LuGre friction model identification. It is used to develop a two-step offline identification methodology of LuGre friction parameters. The genetic simulated annealing algorithm based on the optimization has both not only the capability of globally searching and parallel computation of genetic algorithm, but also the powerful locally searching capability of simulated annealing algorithm, and can improve the identification precision of dynamic friction model greatly. On the basis of introduction of LuGre friction model for the hydraulic simulator, a method for the static and dynamic LuGre friction parameter identifications was derived and applied to hydraulic simulator. The simulation results verify the feasibility and the effectiveness of the method.

Estimation Method for Wake Homing Range

JIANG Tao₁， LIU Kai₁， ZHANG Jiang

2010, 31(6):  860-864.  doi:10.3969/j.issn.1000-1093.2010.06.036

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This paper investigates the estimation method for the acoustic wake homing range

Deployment Optimization of Two Warships Formation for Air Defense

ZHAO Jian-yin, LIU Fang

2010, 31(6):  865-869.  doi:10.3969/j.issn.1000-1093.2010.06.037

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With the weapon system being set, to solve the problems of deployment optimization for two-warship formation, this paper analyzed the disciplines of deployment and air defense area of warship formation, chose depth of inteception as optimal objective, and presented the optimal model and algrithum for two-warship formation for air defense. Under certain data assumption, the paper verified the adaptability and effectiveness for the given model by demonstrating an application.

Study on Model and Algorithm for Stationary Availability Evaluation of Combat Unit

LI Ling-wei, ZHANG Jian-jun, ZHANG Tao, GUO Bo

2010, 31(6):  870-875.  doi:10.3969/j.issn.1000-1093.2010.06.038

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Aiming at problems in the availability study of the combat units (CU), multi-dimensional Markov processes (MDMP) model is established to evaluate the availability of CU. A dimension reduction algorithm is presented for the great amount of states in MDMP model. The multiple equipment in CU are considered in the model. The algorithm reduces the dimension of MDMP based on the relevance of maintenance resources between different parts. The results illustrate that MDMP can model the availability of CU and has comprehensive analytical modeling capacity; the dimension reduction algorithm utilizing the relation information between different parts can reduce the computational load. Lastly, by a numerical example, the practicability of the MDMP model and the algorithm are illustrated.

Establishment of Rapid Extended Manufacturing Chain for Armaments

FANG Ya-dong， ZHANG Lei₂， DU Lai-hong₃， CHEN Hua

2010, 31(6):  876-880.  doi:10.3969/j.issn.1000-1093.2010.06.039

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This paper studies the approach for high-tech armament rapid mobilization and puts forward a solution for the rapid extended manufacturing chain for armaments based on the research on the features of information warfare and manufacturing development. Its establishment feasibility is discussed according to the analysis for the traditional rigid mobilization production and manufacturing outsourcing supply chain. Furthermore, its theoretical basis, establishment process and software system are also introduced to provide a solution for the rapid mobilization. Finally, its application scenario is described through an instance. The application result demonstrates its validity.