Table of Content

30 April 2004, Volume 25 Issue 2

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Paper

Periodic Multi-Rate Kalman Trace Filter Algorithm for a Multi-Rate Sampled-Data System

Liu Shiqian, Guo Zhi, Wang Yuangang, Sheng Andong

2004, 25(2):  129-133.  doi:10.3969/j.issn.1000-1093.2004.02.001

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This paper discussed the problem of a target trace filter for a multi-rate sampled-data system with information lacked at some points, and a periodic multi-rate Kalman filter approach based on the Kalman lilter concept. Angular information of the objective trace at these points can be utilized using the smooth filter and characters of relationships among the state vectors. The best optimization of filter error variance can be guaranteed through the periodic multi-rate Kalman filter. Differences between the periodic multi-rate lilter and usual Kalman filter are shown by filtering a helicopter s trace. The results of the peri?odic multi-rate filter approach showing improved filter precision is proved.

An Image Transformation Technique for the Detection of Artillery’s Rifling Parameter

1：Zheng Jun；2： Xu Chunguang, Xiao Dingguo

2004, 25(2):  134-138.  doi:10.3969/j.issn.1000-1093.2004.02.002

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Aimed at the parameter detection of artillery rifling, an image transformation system was pro?posed .Principle of the rifling parameter detection was discussed by giving the rifle parameter (viz. its angle and distance to a given point) based on the Radon transform and resulting in an image detection method on the rifling parameter. This computes the width and angle of the rifling on the given image with a high anti?noise ability. Influence of image distortion caused by the optical system was analyzed, and formula of cor?rection deduced. This can reduce or eliminate the influence on the rifling parameter detection caused by im?age distortion. An example was finally given to testify, and a resolution achieving high precision and low al?gorithmic cost was given.

A Study on Battlefield Damage Analysis Process and Existing Problems in the Process

Wang Runsheng, Jia Xisheng, LIU Li, Wang Zhicheng

2004, 25(2):  139-142.  doi:10.3969/j.issn.1000-1093.2004.02.003

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Rapid and precise damage assessment can only be carried out successfully when it is based on large amount of damage information. Equipment damage information is the primary source in battlefield damage assessment research. To analyze equipment systematically and gain damage information that possi?bly appears the battlefield damage analysis process was studied. Taking a gun as an example, the paper dis?cussed in detail the process that was developed with basic function item analysis, damage mode and effect analysis, damage tree analysis and damage location analysis, and describes the correlative relations of these analyses. Finally some problems appearing in the process of analyses were indicated. Battlefield damage analysis process addressed in the paper can provide systematic ideas and methods for equipment damage analysis. And it is a practical method for achieving damage assessment information. It is the theory adopted in the development of computer-aided battlefield damage rapid assessment system.

Unit Method m the Calculation of Transmission Velocity Ratio of Mechanisms

Yao Yangwu

2004, 25(2):  143-146.  doi:10.3969/j.issn.1000-1093.2004.02.004

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On the basis of analyses of traditional formulas for the calculation of velocity ratios in mecha?nisms having multiple structural components, the concept of transmission units and nodes were put for?ward, applying the finite element method as a reference. Multi-membered transmission units are reduced to two types of transmission units. Universal formula in the calculation of transmission velocity ratio of mecha?nisms having multiple structural components using the unit method was obtained. The paper developed the methods and steps to calculate the transmission velocity ratio of the mechanism using the unit method, and gave examples of calculation.

Method of Inspection on the Interior Ballistic Performance of Ammunition in Stockpile

Tian Guijun, Yuan Yaxiong, Zhang Xiaobing

2004, 25(2):  147-150.  doi:10.3969/j.issn.1000-1093.2004.02.005

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This paper discussed the ways 01 inspection on the interior ballistic performance of ammunition in stock without the use of standard ammunition or ballistic gun. Based on analysis and study on traditional inspection, a new method of inspection on ammunition in stockpile was presented. The systematic error caused by the artillery itself can be determined with this method independent of either standard ammunition or the ballistic gun by measuring the variation in the inner diameter of the gun barrel before firing. Correct?ing this error and laying down a procedure to control the secondary error rigidly to a minimum replace the method of daily correction. The paper took a gun howitzer as an object of research and made an analysis and practice in the technical ways and operating process for the method of inspection. The concrete methods of operation were finally given.

A Study on the Kinetics of Chemical initiation

Xu Xuezhong, Hao Baotian, Wu Shan,Pei Mingjing， Li Ming

2004, 25(2):  151-154.  doi:10.3969/j.issn.1000-1093.2004.02.006

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The process of chemical reaction dynamics between the ignition agents and fuels was studied to understand theoretically and experimentally the chemical ignition mechanism. Some reaction dynamics pa?rameters of l,2-epoxypropane(PO) and liquefied petroleum gas(LPG) on reacting with BrF3 and NF4BF4 were measured by experiment, and the chemical ignition in confined and unconfined tests were performed. The results of tests show that the chemical ignition process in fuel-air mixture is a typical self-accelcrated chemical reaction with an induction time. In the reaction of initiation agents with fuels and oxygen, some free bonds move to the products from the reaction，which accelerates the chain generation rate，causing the chain generation rate to become much higher than the chain termination rate. The results from the experi?ments show that，for NaBrF4，the activation energy in reaction with LPG and epoxypropane is 6. 2kJ /mol and 22.1 kj/mol respectively, while for NF4BF4, it is 8.9 kj/mol and 6.1 kj/mol respectively, far less than the general reaction activation energy (41. 84?418.4kJ/mol) . The induction time for the reaction is in the region 0.1?lms. The results of the chemical ignition under the confined and unconfined conditions show that the agents (BrF3, NF4BF4) could ignite the LPG and epoxypropane cloud effectively.

A Study on the Properties and Applicaion of High Energy Density Material DNTF

Hu Huunxiang, Zhang Zhizhong, Zhao Fengqi,Xiao Chuan， Wang Qinhui， Yuan Baohui

2004, 25(2):  155-158.  doi:10.3969/j.issn.1000-1093.2004.02.007

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DNTF is a novel high energy density material. It has been proved that DNTF has better prop?erties than those of HMX，and vicinal properties of CL-20 through investigation of its physico-chemical and detonation properties. DNTF possesses high energy, low melting point, good thermal stability and moder?ate sensitivity. It can be used in solid rocket propellant, warhead and explosive net with a broad prospect of applications. DNTF can form eutectic mixture with TNT and in liquid phase carriers having different melt?ing point and different energy requirements can be prepared through the use of DNTF. The application of DNTF blazes a new traii for melt-cast explosives.

Fast Fractal Image Coding Based on Sums of Range and Domain Blocks

Mu Xiaomin, Yang Shouyi, Zhang Dehui

2004, 25(2):  159-162.  doi:10.3969/j.issn.1000-1093.2004.02.008

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In recent years, fractal image compression has received much attention due to its several ad?vantages. However, finding a close match between a range block and a large pool of domain blocks in fractal image block coding is quite time-consumptive. The paper discussed theoretically the relationship between the distance of a range block with domain blocks and the block gray value sums，and then proposed a fast fractal image coding method. Using this fast coding method, the searching space for finding a matching do?main block of a range block is much reduced, and the coding speed made much higher than with the ex?haustive searching method. Experimental results for images boat and peppers show the effectiveness of this method.

X — ray Radiographic Scatter and Its Correction in Industrial Applications

1：Chen Shuyue；2：Lu Hongnian

2004, 25(2):  163-166.  doi:10.3969/j.issn.1000-1093.2004.02.009

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X-ray radiographic scatter is one of the important factors degrading image quality. Based on experiments, the influence of scattering on imaging quality in industrial X-ray radiography, rules of scatter?ing and its correction were studied in the paper. The relationship between scatter and specimen thickncss was obtained through the design of the test system and experiments. The new exponential model of scatter?ing was presented by modification of conventional model，and the method of scattering correction was de?scribed by means of Wiener filter and the established model, it is shown that effects of scattering on imag?ing quality is removed effectively through the application of the proposed process and the radiographic spatial resolution is improved by DO %

Performance Analysis of Turbo Code in Short-Frame Data Services of 3GPP

Wang Qiang, Sun Jintao, Rui Yibin, Ye Xiaodong

2004, 25(2):  167-170.  doi:10.3969/j.issn.1000-1093.2004.02.010

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In UMTS/3GPP standards, International Telecommunication Union recommend the useof 8-states turbo codes and 256-states convolutional codes as data error-correcting schemes. Based the distance spectrum of turbo codes, this paper presented tfie corresponding BER performance union bounds in short-frame data transmission, which was proved by simulation results. Compared with Convolutional codes, simulation results also show that turbo codes have better BER performance and lower decoding complexity at SNR above 1.75dB.

New Fast Algorithms of Fourth-Order Cumulant Based Sign Iterative Adaptive Dynamic Line Enhancer

1:Guo Yecai;2:Zhao Junwei, Chen Huawei

2004, 25(2):  171-174.  doi:10.3969/j.issn.1000-1093.2004.02.011

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To reduce computational complexity in cumulant estimates and to overcome the ineffectiveness in suppressing Gaussian noice of LMS algorithms，the paper analyzed the relationship of cumulant recursive algorithm with computational complexity and developed new fast algorithms of fourth-order cumulant diago?nal slice- based sign iterative dynamic line enhancer. In these algorithms, coefficients of adaptive filters are updated by sign iterative algorithm. Performance of the proposed algorithms in suppressing Gaussian noise was much better than that of the LMS-based adaptive line enhancer and cumulant-based non-sign iterative algorithm. The computational complexity of cumulant-based sign iterative algorithms is only half that of the cumulant-based non-sign iterative algorithm. Computer simulation with underwater target- radiated data was also included. Its results testify the effectiveness of these algorithms and show that sign iterative algo?rithm of non-input signal is the best among all sign iterative algorithms in suppressing Gaussian noise.

The Extinction of Infrared by Micro Sphere Particles Having Logarithm Nomial Distribution

Qiao Xiaojing, Feng Changgen, Zhang Tonglai

2004, 25(2):  175-177.  doi:10.3969/j.issn.1000-1093.2004.02.012

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The extinction of infrared by shell-core micro spheres in logarithm normal distribution was studied and the mass attenuation coefncient of metal coated spheres calculated in infrared with a program prepared by the authors. The mass attenuation coefficient of the shell-core spheres in logarithm normal dis?tribution was compared with that of mono-size spheres. The results show that the range of granularity in the mass attenuation coefficient is narrower when the wavelength is shorter. When the wavelength increases the maximal mass attenuation coefficient reduces and the corresponding optimum size of the spheres increas?es. In a suitable range of granularity the mass attenuation coefficient of the mono-size spheres is larger than that of the spheres in logarithm normal distribution and the shorter the wavelength the narrower will be the range. 1W ith the same wavelength and shell thickness, the extinction effect of spheres coated with alu?minum the best. While the extinction of spheres coated with copper compares better than that coated with silver.

A System Reliability Demonstration Method Based on Bayes Theorem

Feng Guangbin, Qian Linfang

2004, 25(2):  178-181.  doi:10.3969/j.issn.1000-1093.2004.02.013

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A final system reliability demonstration testing is needed before the system is released for pro?duction. According to classical reliability, a large sample size is required to demonstrate system reliability as the demonstration does not make use of all information in the system development process. The paper pre?sented a Bayesian framework oi integrated reliability demonstration in system development. The proposed framework relies on component design analysis as the prior reliability knowledge of the components. Results of life test of the components are used to update the reliability of components. The updated reliability of components is then integrated to form the prior reliability knowledge of the system according to system structure. Based on the prior reliability of the system, a reliability demonstration test plan of the system was developed. An example illustrates this process and application issues are addressed. With this frame?work, the importance of upfront design and development on system reliability is clarilied, and the sample size required to demonstrate system reliability can be much reduced compared with that required by classical reliability theory.

Observability Criteria Based on Bearing-Only Measurements for Three-Dimensional Moving Targets

1:Dou Lihua, Hou Chaozhen;2:Yang Guosheng

2004, 25(2):  182-185.  doi:10.3969/j.issn.1000-1093.2004.02.014

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Based on the study on a target moving in a 3-dimentional space with constant acceleration, a necessary condition based on bearing-only measurements was deduced to assert the observability of the states for the moving target. In the course of obtaining this condition, the non-linear bearing measurement equa?tion is first changed into a linear framework by subtly making use of some mathematical transformations; and then a high-order non-linear differential equation is recasted into a set of single order linear differential equations utilizing some characteristics of full-rank matrices. At the end of this paper, the observability cri?teria given by previous researchers for a target traveling in 3-dimentional space with a constant velocity is directly derived from the conditions presented in this paper.

A Study on the Screening and Processing of Army Weaponry Development Cost Data

1:Bai Hua, Jiang Yixun;2:Song Chunli

2004, 25(2):  186-188.  doi:10.3969/j.issn.1000-1093.2004.02.015

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The authenticity and credibility of developing cost data form the basis and premises of econom?ic analysis in weaponry development, so a study on the method of screening and processing of cost data must be strengthened. On the basis of an analysis of the traditional screening and processing method of cost data, and combining with cnaracteristic particular to weaponry development, a new screening and processing method of cost data the method of expert qualitative opinion quantifying was suggested. A discussion was given on the transformation of expert qualitative opinions into a quantitative standard to screen and pro?cess the development cost data, and to provide the detailed processing.

Mathematical Model for the Relationsmp between Instructions and Its Coefficients for a Missile

Sun Wenjie, Su Hao, Li Chengjia, Zhou Guangzheng,Liu Feng

2004, 25(2):  189-192.  doi:10.3969/j.issn.1000-1093.2004.02.016

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A missile transmitting instrustion and datum singals separately has area of instruction block?age. The area limits the ranges of instuction opening angle and central angle, and will causes errors in in- stuction coefficients. In order to have the instruction coefficient through math calculations in accord with the actual situation, the effects from the instruction coefficients were studied and an intelligent logical rea?soning math model of relationship between the instruction and its coefficients was set up.

Preparation and Characterization of SrAl204： Eu2+, Dy3+ Long after-Glow Phosphorescence Ceramics by Solid Phase Reaction

Zhang Xiyan, Lu Liping, Wang Xiaochun, Liu Quansheng, Bai Zhaohui,Cao Zhifeng

2004, 25(2):  193-196.  doi:10.3969/j.issn.1000-1093.2004.02.017

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SrAl2O4:Eu2+,Dy3+ phosphorescence ceramics samples were prepared by solid phase reaction at high temperature under reducing atmosphere through dry press processing. The sample shows high strength and good chemical durability. The samples emit bright green light after being excited by natural light. The effects of sintering temperatures on the microstructure and phosphorescent properties were stud?ied. XRD analysis indicates the SrAl204 ： Eu2+, Dy3+ ceramic is formed at 1250 ?1450℃ but the optimum sintering temperature was found to be 1400°C . SEM observation indicates that the sample shows tight mi?crostructure at 1400°C for 4h. Spectrum analysis indicates that the sample exhibits a broad emission peak?ing at 520nm and excitation spectrum consists of four peaks at 240nm, 320nm, 360nm and 420nm ranging from 240?480nm. The characteristics of the intensity decay is fitted by I = At -n equation, n=0.6 for the beginmg 5 minutes, n ニ 1.0 for 5?40minutes and w = 1.3 for 40?600minutes. The phosphorescence intensity is 2.15mcd/m2 even for IOh after removal of a 40W fluorescent lamp excitation source. This type of ceramic sample can find applications in war at night time.

Micro-Void Evolution in the Adiabatic Shear Bands

Tan Chengwen, Wang Fuchi, Li Shukui, Su Tiejian

2004, 25(2):  197-199.  doi:10.3969/j.issn.1000-1093.2004.02.018

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In order to understand the law of evolution of micro-voids in the aaiaoatic shear band, and open out the special failure rule when materials under high strain rate are loading，restricted detonation ex?periment was adopted to study steel D35. Tubes loaded by high explosive were observed by scanning elec?tron microscope (SEM) ? Micro-voids nucleation，growth，and coalescence to damage in adiabatic shear bands (ASB) were observed by SEM. Based on the experimental results from Guduru，s tests to ASB tem?perature field and Li Shaofan，s simulation, the predigestion were applied to modify Timothy and Nutch- ings’ model, viz. that (I)the temperature in ASB center is the Highest, and fall linearly to be the same as the other places, (2) micro-voids’ nucleation and growth in the ASB are controlled by temperature, and the growth velocity is exponential. The modified model can interpret the micro-void? s nucleation, growth, and coalescence quantitatively.

Studies on the Behaviors of Adsorption of Nd (Ⅲ) onto the Functional Polymer- Iminodiacetic Acid Resin

1:Wang Yongjiang,Wu Xiangmei;2:Xiong Chunhua,Zhu Binglin

2004, 25(2):  200-203.  doi:10.3969/j.issn.1000-1093.2004.02.019

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Slide Position Control in the Mechanical Press

1：Zhao Hong；2:Zhao Shengdun, Zhou Mingyong, Luo Chuangang, Lin Tingqi

2004, 25(2):  204-208.  doi:10.3969/j.issn.1000-1093.2004.02.020

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A new computer control system for the control of the slide in a mechanical press to insure on a accurate positioning was proposed. The control system is made up of the pneumatic proportional valve, pneumatic friction clutch and brake, displacement sensor etc. The working process and control principle were analyzed and described. It is obvious that fuzzy control strategy is appropriate for use in the control system. Design of the fuzzy controller was given in details. Experiments were carried out in the mechanical press model JH23-63.The results reveal the effectiveness and usefulness of the algorithm.

Design of Intake Manifold and Experimental Stuay for Pressure Wave Supercharged Diesel Engines

Ji Changwei, Han Aimin, Zhao Yong, Ma Hui

2004, 25(2):  209-213.  doi:10.3969/j.issn.1000-1093.2004.02.021

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A SOFIM turbo-charged diesel intake manifold was taken as the reference in the design of pressure wave supercharged diesel intake manifolds. Orthogonal experimental design method was employed to determine the grouping of test intake pipes. Using 3-D UG Graphics, the geometric modeling and struc?tural analysis for these pipes were performed to find the intake pipe with the least mass and largest inner volume. Based on ANSYS, flow characteristics analysis for the manifold was then done to find the pipe with the largest average flow rate. Following the structural and flow analysis tlie final optimized intake manifold was determined for the PWS diesel. The new prototype and the original manifold were compared on the flow bench. The test results show that the new pipe induced nearly 7% more air than the original design. Finally the manifold cast in aluminium alloy was compared with the original on the engine test bed. JTest results show that the pipe induced nearly 6. 54% more air than the original at medium-low speeds and 4.65% at medium-nigh speeds.

Short Papers

Design of Anti-Radiation Missile Seeker Follow-Up System Driven by Pulse-Width Modulation

Yang Yanjuan ,Jin Zhihua, Tian Weifeng

2004, 25(2):  214-217.  doi:10.3969/j.issn.1000-1093.2004.02.022

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Describes briefly two existing anti-radiation missile (ARM) seeker follow-up systems, viz. the hydraulic pressure servo ARM seeker follow-up system and eiectromotion ARM seeker follow-up system. On the basis of retaining their superiority, a new strapdown ARM seeker follow-up system with better per?formances was suggested. In this system the inertial measurement unit is fixed on the vehicle directly. It adopts the classical proportional integral differential control, witn its servomechanism adopting DC moment motor driven by pulse width modulation working on proportion guidance. The paper analyzed the perfor?mance and characteristics of the ARM seeker follow-up system in detail. Theoretical analysis and simulation show that the ARM seeker follow-up system inherits the excellence of the above two ARM seeker follow-up systems that the structure of the system is simple, and that the effect of the missile attitude movement to steady-state response of the ARM seeker follow-up system is eliminated with integral control. Simulation results also show that the designed system has good tracking performance.

Experimental Techniques and Analysis

Radar Range Profile Classification Based on Fuzzy Min-Max Neural Networks

1：Tang Guanghua, LiU Guosui；2：Dai Yi

2004, 25(2):  218-221.  doi:10.3969/j.issn.1000-1093.2004.02.023

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Radar target classification based on the target’s range profile is a subject worthy of attention. Radar target’s range profile changes when the aspect of radar target is changed. Change in aspects goes on continuously, so the range profile also changes continuously. Radar target’s range profile may form a fea?ture Js orbit in radar target’s range profile feature space as the aspect of radar target changes continuously. In this paper, based on linear interpolation neural network, another method was given to form the feature’ s orbit of radar target’s range profile, i.e. ,a method to classify radar target’s range profile based on fuzzy min-max neural networks. The merging of the same kind of target’s fuzzy set hyperboxes is used to form the radar target’s range profile feature’s orDit? Range profiles of three kinds of planes from 0 to 180 de?grees were used for classified experiments. The results indicate that use of fuzzy min-max neural network classifiers in classifying radar target range profiles gives higher recognition rates.

Research Notes

Fuze Test-Bed Based on VXI Bus Technology

1：Rui Xiaoting, Gu Jinliang,Lu Wenguang；2：Sha Nansheng

2004, 25(2):  222-224.  doi:10.3969/j.issn.1000-1093.2004.02.024

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The groundwork and approach in its implementation of the fuze test-bed based on the VXI bus technology were described. This system had been applied in fuze design and fuze tests. It shows a good per?formance during the experiments. The test results had been verified by theoretical analysis and numerical simulations. Practical experience shows that the system has high reliability and scalability. The software used is open and easily transferee!. A direct test means and an physical simulation platform were provided for fuze design and failure analysis.

Method of Mathematical Calculation for the Effect of Oxygen Balance on the Explosion Property ofPowdery Ammonium Nitrate Explosives

Lu Ming ,Lu Chunxu

2004, 25(2):  225-228.  doi:10.3969/j.issn.1000-1093.2004.02.025

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Mathematical model for the formulation design of powdery ammonium nitrate (AN) explosives was studied. The theoretical explosion heat, specific volume and toxic gas volume of AN explosive without TNT, AN explosive containing TNT and fuel oil, as well as AN explosive containing aluminum powder and TNT at different oxygen balance values have been calculated respectively. The following results are con?firmed, viz. that when the oxygen balance value of powdery AN explosive is decreased, the theoretical ex?plosion heat is reduced, the specific volume increases, and toxic gas volume also increases. In this paper, a method for formulation design was proposed, in which maximum theoretical explosion heat was obtained at an assumed oxygen balance condition. A way for the predictable calculation of the theoretical explosion heat, specific volume and volume of toxic gas AN explosive was suggested. These are useful for the deter?mination of AN explosives formulation.

A Quartz-Tube Thickness Laser-Scanning on-Line Inspecting System

Xu Xiping, Zhang Guoyu, Fu Xiuhua, An Zhiyong， Li Chengzhi， Yang Jixing

2004, 25(2):  229-231.  doi:10.3969/j.issn.1000-1093.2004.02.026

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Based on the laser-scanning inspecting principle and optoelectronic sensor technigue, a quartz- tube thickness laser-scanning on-line inspection system was presented. Dimensional positions of two laser beams formed by the reflected beams from a beam incident to the outer face of the quartz-tube and then re?flected respectively by the inner and outer surfaces of the tube, are measured. As a result, non-contact on?line measurement of the quartz-tube thickness was achieved. In this paper, the working principle, the over?all structure and the real-time signal processing system of the system were described. The measuring preci?sion of the system is verified by experiment attaining ±0.01mm.

A Study on the Algorithm of Doppler Resolution of signals Resembling Rectangular Pulses

GuO Qiang, Tao Ran, Wang Yue, Zhou Siyong

2004, 25(2):  232-237.  doi:10.3969/j.issn.1000-1093.2004.02.027

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The calculation for the nominal velocity resolution parameter and Doppler resolution constant of a signal made up of several rectangular pulses according to the definition is always complex, especially when it is a multiple-period signal. Apart from the definition of the resolution, tne paper put forward a novel algorithm to search for the row of the ambiguity function matrix where the “half power point exists and then solves the problem mentioned a Dove. In addition, the result of the signal in single periods is used to calculate the Doppler resolution constant of sync-plus-white signal m several periods and the integral of high power terms of the envelop function is simplified, avoiding complicated and duplicated calculations and raising the efficiency.

Extration of Low Frequency Line Spectrum of Ship Radiated Noise Based on the 1 1/2 D Spectrum

Li Yaan, Feng Xian, Fan Yangyu, Huang Jianguo

2004, 25(2):  238-241.  doi:10.3969/j.issn.1000-1093.2004.02.028

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Special properties of a I spectrum were analyzed. By means of these properties, the Gaussian noise and symmetrically distributed noise can be restrained. The fundamental frequency compo?nent of the harmonic signals can be enhanced and non-quadratic phase coupling harmonic components can be eliminated. By calculating the I spectrum of actual ship radiated noise, fine results in classification and identification have been achieved. Tins will be of help in the research of detecting and identifying underwa?ter objects.

Method and ADplication of Parameter Estimation in Weapon Impact Dynamics

1:Guo Kai,Gu HongBiao;2: Xu Cheng ,Pu Xiongzhu

2004, 25(2):  242-245.  doi:10.3969/j.issn.1000-1093.2004.02.029

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A dynamic model for in low-speed impact systems conventional weapons was built up in this paper. The system identification method for timely-changed, non-linear differential equations was given, in which the least square method and the algorithm of self-fitted step-time were combined. The method of analysis for the low-speed impact system is usually divided into two types ： rigid impact and elastic impact of which the elastic impact model is applied in this study. An automation mechanism example for small-arms was put forward and analyzed. The stiffness and damping were calculated for the gun，s back impact move?ment. These parameters were provided for further simulation of small-arms. The results show that the method mentioned has its flexibility, feasibility and practicability.

Design of High Velocity Arc Spraying Gun

Liang Xiubing, Xu Binshi, Ma Shining

2004, 25(2):  246-248.  doi:10.3969/j.issn.1000-1093.2004.02.030

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High velocity arc spraying is one of the high tech processes in thermal spray devices where the high velocity arc spraying gun is the key equipment. High velocity airflow is adopted and supersonic nozzle is used in the design of a HVAb gun. The axial airflow speed of the gun is kept at approximately 600m/s at a distance of some 80mm from the gun outlet, which makes the velocity of Al particles sprayed arrive at 340m/s. The sprayed particles have a velocity 1.4 times that of the traditional arc spraying, which makes the quality and behaviors of the coating improved. The successful development of HVAS gun sets a founda?tion for its induvStnai applications.

Remote Intelligent Inspection,Diagnosis and Maintenance of Weapons

Sun Yu, Zhang Rongtao, Zhang Xiaoyang

2004, 25(2):  249-251.  doi:10.3969/j.issn.1000-1093.2004.02.031

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An analysis on the research, application and characteristics of remote intelligent inspection, diagnosis and maintenance was given in this paper. A model for the system structure of remote intelligent inspection, diagnosis and maintenance of weapons was established. The model consists mainly of three parts： field diagnosis ana maintenance, local repair and center of remote diagnosis and maintenance. Func?tions of each part are described, including remote intelligent inspection and diagnosis, portable and embed?ded intelligent inspection node, as well as rapid maintenance and agile logistic management. Some applica?tions of the technology were finally discussed.

Construction and Optimization of Combined Function Cam Profile for Avoiding collision

1:Long Lianchun, Sui,Yunkang;2:Hu liping

2004, 25(2):  252-256.  doi:10.3969/j.issn.1000-1093.2004.02.032

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A new type of combined function cam profile for avoiding collision was presented. It can be used in a valve train when restricted by the requirement of avoiding collision. This type of cam profile has a large value of valve-opening time-area beside having good dynamic characteristics. Design method for the cam profile was given. A complicated multi-freedom analysis model was established to understand the dy?namic characteristics of the valve train clearly. Based on these，an optimization design model was estab?lished . The example given shows that the effect of avoiding collision in this cam profile is well accomplished and that the valve train has accepted general properties simultaneously. Consequently, it is good for use in diesel engines to increase its performance in general ana the time-area of cam profile. Outer characteristic of a diesel engine adopting the optimized cam profile was also shown.