Table of Content

01 November 2012, Volume 33 Issue 11

Previous Issue    Next Issue

Paper

Improved Design for Top Carriage of a Gun

SUN Quan-zhao, YANG Guo-lai, GE Jian-li

2012, 33(11):  1281-1285.  doi:10.3969/j.issn.1000-1093.2012.11.001

Asbtract ( )   PDF (1250KB) ( )  

References | Related Articles | Metrics

To improve the stiffness of a gun's top carriage, an modified design was conducted by using the structural optimization based on the path of force transmission. The static stiffness and strength were calculated by using the finite element method, and the weak links in the original design were analyzed. The topology optimization was used to find the main path of force transmission and search for the best material distribution, and then the layout of stiffeners was modified. The detailed design was accomplished by using size optimization, and the thicknesses of major plates were determined. The stiffness and strength of the improved top carriage were enhanced after optimization, the maximal displacement reduced by 32.7%, the center variation of trunnion chamber declined by 52.1%, and the maximal stress decreased by 20.0%, while the mass only increased by 1.9 kg. The results show that the expected goal is achieved.

Dynamics Analysis for Wheeled and Tracked Multiple Launch Rocket System

WANG Guo-ping, RUI Xiao-ting, YANG Fu-feng, XU Hao

2012, 33(11):  1286-1290.  doi:10.3969/j.issn.1000-1093.2012.11.002

Asbtract ( )   PDF (1042KB) ( )  

References | Related Articles | Metrics

The launch dynamics characteristics of tracked multiple launch rocket system (MLRS) were studied and compared with the dynamics characteristics of wheeled MLRS, and a method to improve firing dispersion was proposed. The launch dynamics model, vibration characteristics, dynamics response analysis and simulation system of a tracked MLRS were developed by using the transfer matrix method of multi-body system and launch dynamics theory. The simulation results of vibration characteristics were validated experimentally. The vibration characteristics, dynamics response, rocket initial disturbance and firing dispersion of wheeled and tracked MLRS were compared and analyzed. The analysis results show that there are some differences among them. The dynamics characteristics of tracked MLRS are better than that of wheeled one.

Simulation Study on Residual Stress in Cold Radial Forged Barrel

LIU Li-li， FAN Li-xia， XU Cheng

2012, 33(11):  1291-1297.  doi:10.3969/j.issn.1000-1093.2012.11.003

Asbtract ( )   PDF (1102KB) ( )  

References | Related Articles | Metrics

The barrel is a key part of automatic weapon. The cold radial forging process is a new technology for manufacturing the barrels. The cold radial forged barrels usually need to be machined further, and are used under dynamic high temperature and pressure conditions later. The dimensional accuracy in the barrel’s subsequent processing and its fatigue life are affected by residual stress in it, which is induced by cold radial forging. An axisymmetric model was established to simulate the cold radial forging process of barrel and the subsequent spring-back, the residual stress distribution in the barrel was obtained, and the effects of process parameters on the residual stress in the barrel were analyzed. The results can be used to control the residual stress in the forged barrel.

Research on Residual Stress of Hydraulic Autofrettaged Barrel in Practice Firing

LI Kui-wu, ZENG Zhi-yin, NING Bian-fang, LIU Peng-ke, GAO Xiao-ke, WU Hui-min

2012, 33(11):  1298-1302.  doi:10.3969/j.issn.1000-1093.2012.11.004

Asbtract ( )   PDF (1540KB) ( )  

References | Related Articles | Metrics

Based on the theory model of residual stress of hydraulic autofrettaged barrel, the magnitude of initial residual stress on inner surface of barrel and it’s distribution were discovered. By using Sachs test theory and method on the boring residual stress, the remaining residual stress of autofrettaged barrel was determined in given rounds of firing experimentally. According to the initial and remaining residual stresses obtained from theoretical analysis and experiment test, the expression describing the residual stress change with the rounds of firing was founded by data fitting.

Study on Preparation and Luminescence Performance of SrMoO₄:Eu³⁺ Fluorescent Powder Used in White-light LED

ZHANG Chi-jun, LI Xi-lin, LONG Dan-dan, ZHANG Qing-xia, YAN Jing-hui, KANG Zhen-hui

2012, 33(11):  1303-1309.  doi:10.3969/j.issn.1000-1093.2012.11.005

Asbtract ( )   PDF (1419KB) ( )  

References | Related Articles | Metrics

Eu³⁺-doped SrMoO₄ red fluorescent powder which matches well with UV and blue light emitting diodes (LED) were prepared by using hydrothermal route. The samples were characterized with X-ray diffraction (XRD), field environmental scanning electron microscopy (FESEM) and photoluminescence (PL) spectroscopy. The results of XRD are in agreement with the standard PDF # 85-809; the FESEM images show the morphology of the samples sintered under different temperatures; the main emission peak of the sample excited by ultraviolet or blue light is at 616 nm. It is investigated that the luminescent properties of the samples have some relationship with the doping concentration of Eu³⁺ and the critical concentration of Eu³⁺ is 7%. The critical sintering temperature is found to be 600 ℃. The sample’s properties can be improved by introducing different compensation charges, and the luminescent intensity of the sample is maximum when using K⁺ as the compensation charge. The color coordination of SrMoO₄:Eu³⁺, K⁺ is (0.59, 0.40), and it can be used as the red fluorescent material for white LEDs.

Calculation and Image Simulation of Aircraft Infrared Radiation Characteristic

LI Jian-xun, TONG Zhong-xiang, WANG Chao-zhe, CHAI Dong, LI He， ZHANG Zhi-bo

2012, 33(11):  1310-1318.  doi:10.3969/j.issn.1000-1093.2012.11.006

Asbtract ( )   PDF (1993KB) ( )  

References | Related Articles | Metrics

In high-altitude and high-speed flight, the infrared image acquisition is time-consuming and costly, and the different conditions affect the infrared imaging greatly. In order to solve such problem, a calculation method for infrared radiation characteristics of the aircraft skin, final nozzle and plume in different wave bands and different angles were proposed on the basis of the analysis on the infrared radiation characteristics of aircrafts. And an infrared imaging simulation model of airplane was presented. The object, class and man-machine interface were designed by using object-oriented technology. The dynamic infrared images were programmed on VC software platform．In the infrared guidance and firepower control, the infrared images can be helpful for the research on target detection and tracking.

Simulation on Detection Range of Infrared Detector for Flying Projectile

ZHANG Bao-hui, ZHANG Jun-ju, CHANG Ben-kang ,YUAN Yi-hui，CHEN Zuo-long, QIAN Yun-sheng

2012, 33(11):  1319-1323.  doi:10.3969/j.issn.1000-1093.2012.11.007

Asbtract ( )   PDF (990KB) ( )  

References | Related Articles | Metrics

The detection range of infrared system depends on its dynamic characteristic, the radiation of target and background, the atmospheric attenuation and so on. Aimed at the flying projectile’s relative radiation received by the infrared system, a new detection range model of infrared system was proposed. It considered the equivalent area radiation of the projectile and the equivalent background radiation around the projectile and atmospheric attenuation. Based on analysis of infrared radiation on the surface of projectile, a new calculation equation for detection range was derived and analyzed.

Static Pose Measurement of Gun Barrel Based on Monocular Vision

ZHU Yao-xuan, DUAN Xiu-sheng, WANG Chun-ping, ZHANG Qi-long

2012, 33(11):  1324-1328.  doi:10.3969/j.issn.1000-1093.2012.11.008

Asbtract ( )   PDF (1374KB) ( )  

References | Related Articles | Metrics

The pose measurement of gun barrel is difficult in the precision analysis of self-propelled antiaircraft gun (SPAAG) fire control system. To solve this problem, a non-contact and direct measurement method based on monocular vision was proposed. A checked planar template was fixed on the gun barrel as a marker which is within the field of view of a camera. Both elevation angle and azimuth angle were measured. Firstly, the coordinates of corner points were obtained by using Harris corner detection algorithm to calibrate the camera, and the camera’s intrinsic parameters were obtained by solving the camera model. Then, combined with LSE algorithm, the extrinsic parameter matrix of the corresponding position was found according to the stability of solutions in PnP problem. Finally, based on the motion model of gun barrel and its position relative to the marker, two angles were figured out. Simulation and experiment results show that the method can measure the barrel pose easily and accurately.

Iterative Filter and Optical Flow Estimation Matching of Feature Points in Rotary Jitter Compensation

WANG Bin-rui， XU Yin， JIN Ying-lian， WU Shan-qiang

2012, 33(11):  1329-1334.  doi:10.3969/j.issn.1000-1093.2012.11.009

Asbtract ( )   PDF (2386KB) ( )  

References | Related Articles | Metrics

Rotary jitter compensation is a difficulty in video image stabilization. The feature point matching and inaccurate point filtering were studied. An affine model with 6 parameters was established for moving images, and an over-determined equation to estimate motion parameters was derived. The least squares iterative algorithm was used to remove error feature points judged by sum of absolute difference (SAD) matching algorithm. A pyramid-style Lucas-Kanade (LK) algorithm based on optical flow was adopted for feature point matching of rotary video. All algorithms were programmed. After detecting feature points by using the gradient matrix of the feature window (KLT) method, SAD and LK algorithms were used to match feature points respectively, and the rotation matrix parameter errors were obtained and compared. The reasons of matching error were analyzed. Kalman filter was used to smooth rotation parameters. All algorithms were implemented on an autonomous robot. The experiment results show that LK can get less matching errors than SAD for rotation jitter, and Kalman filter makes the maximum 8.37° rotation jitter less than 3.68°, thus it can compensate the rotary video effectively.

Inversion Identification of Constitutive Model of Cohesive Zone in HTPB Propellant

HAN Bo, JU Yu-tao, ZHOU Chang-sheng

2012, 33(11):  1335-1341.  doi:10.3969/j.issn.1000-1093.2012.11.010

Asbtract ( )   PDF (1433KB) ( )  

References | Related Articles | Metrics

There exists a nonlinear cohesive zone at the crack tip in stretching hydroxyl terminated polybutadiene (HTPB) propellant, and the accuracy of its constitutive model can affect the fracture simulation greatly. In order to establish a precise constitutive model, an experiment-based inversion method was presented. The cohesive fracture energy and fracture strength were obtained experimentally, and the constitutive curve parameters of cohesive zone were determined by using the finite element model updating approach. The established constitutive model was applied to the crack initiation and propagation simulation. The results indicate that the presented method is simple and feasible, and it can predicate the crack initiation and propagation in HTPB propellant accurately.

A Kind of Conserved Quantity Induced by Lie Symmetry of Nonholonomic Mechanical System

SHEN Yue, ZHANG Ling-tan

2012, 33(11):  1342-1345.  doi:10.3969/j.issn.1000-1093.2012.11.011

Asbtract ( )   PDF (916KB) ( )  

References | Related Articles | Metrics

It represents important not only theoretical but also practical significance to study the symmetry and conserved quantity of nonholonomic mechanical system. A kind of conserved quantity directly induced by Lie symmetry is studied by using infinitesimal group transformation analysis. Firstly, the criterion of Lie symmetry for nonholonomic mechanical system is given. Secondly, the existential condition of the conserved quantity and its forms are obtained. Finally, an example is given to illustrate the application of the results.

Restrain Effect of Hollow Cone Striker Bar on Incident Pulse Dispersion of Split Hopkinson Pressure Bar

ZOU Guang-ping, WANG Xin-zheng, CHEN Jian-jie, CHANG Zhong-liang

2012, 33(11):  1346-1351.  doi:10.3969/j.issn.1000-1093.2012.11.012

Asbtract ( )   PDF (1303KB) ( )  

References | Related Articles | Metrics

In order to reduce the dispersion of incident pluse, the geometric dispersion of incident pulse of conventional split Hopkinson pressure bar（SHPB) were analyzed with dynamic finite element software. It was found that the geometric disperse became intensive along the direction of stress wave propagation, and weakened from center to outside surface. Then, a hollow cone was made coaxially in the end of solid cylindrical impact bar, and the modified bar was called as the hollow cone impact bar. Its effect on the incident pulse dispersion was studied numerically. The results show that the rise-time of incident pulse becomes large, and the geometric dispersion reduces more obviously with the larger cone radius and the smaller cone angle; the frictional effect between the impact bar and incident bar may be negligible, but the phase of oscillation is changed. The effect of modified bar was proved experimentally. The experiment results agree with the theoretical analysis and numerical simulation better.

A Damage Assessment Model Based on Adaptive Neuro-fuzzy Inference System

WU Zheng-long, ZHAO Zhong-shi

2012, 33(11):  1352-1357.  doi:10.3969/j.issn.1000-1093.2012.11.013

Asbtract ( )   PDF (959KB) ( )  

References | Related Articles | Metrics

A novel model for predicting artillery firing damage effect to group target based on adaptive neuro-fuzzy inference system (ANFIS) was presented. After damage probabilities under different firing conditions were calculated based on law of burst coordinate, an ANFIS was trained to learn the mapping model between damage factors and probability. It was then used to assess the firing damage. Experiment results show that the differences between the outputs of ANFIS and simulation results are about 3% or so, and it indicates that the model has satisfying accuracy and extensive ability.

Damage Probability Calculation Model of Rapid-fire Gun Based on Common Component Decomposition

TAO De-jin, SHI Hui-min, WANG Jun, BO Yu-ming, GUO Zhi

2012, 33(11):  1358-1363.  doi:10.3969/j.issn.1000-1093.2012.11.014

Asbtract ( )   PDF (952KB) ( )  

References | Related Articles | Metrics

For rapid-fire guns, the stationary normal shooting error sequence was decomposed as common and uncommon components; furthermore, the common component was decomposed as prediction value and prediction error. Based on the above decomposition, the expression of mean damage probability was proposed for the shooting process in certain initial values with strong and weak correlation errors; then the expression of damage probability of the weapon systems was given for uncertain initial values. Compared to the current damage probability calculation models including those listed in the national military standards, the model given is more accurate.

Adaptive Path-following Control for Miniature Autonomous Helicopter

WANG Qiang， HUO Wei

2012, 33(11):  1364-1372.  doi:10.3969/j.issn.1000-1093.2012.11.015

Asbtract ( )   PDF (1365KB) ( )  

References | Related Articles | Metrics

A novel adaptive path following controller was presented for a miniature autonomous helicopter with uncertain inertial parameters and external disturbance. It was implemented by using dual-loop structure, including an outer-loop for path following and an inner-loop for attitude control. The outer-loop controlled the attitude angles and lift forces to track the expected path and velocity, and the inner-loop was designed as a attitude controller based on L₁ adaptive controller. The uncertain inertial parameters were and external disturbance were also compensated online by using parameter adaptive update laws in the inner-loop. The stability analysis for the inner- and outer-loop was provided separately and the closed-loop stability analysis was given on the basis of time-scale separation assumption. Finally, a simulation and a flight test were carried out. The results demonstrate that the feasibility and performance of the proposed controller.

Research Notes

Research on Output Regulation of Rocket Laucher Subjected to Platform Disturbance

ZHUANG Wen-xu， MA Da-wei， LE Gui-gao

2012, 33(11):  1373-1378.  doi:10.3969/j.issn.1000-1093.2012.11.016

Asbtract ( )   PDF (1192KB) ( )  

References | Related Articles | Metrics

To restrain the influences of both dynamics and kinematics disturbances from platform on the control precise of a multitube rocket launcher, a mathematical model of integrated system was established on the basis of permanent magnet synchronous motor (PMSM), and an output regulation method was applied. Because of requirements of exactly known the frequency information of external disturbance and slower convergence of adaptive internal model in normal output regulation problem (ORP), a novel output feedback regulation strategy was designed, including spectrum analysis to estimate the frequency of external disturbance signal, state observation and invariant manifold. Simulation and experiment results demonstrate that the proposed control strategy performs well in depressing the coupling disturbance of rocket platform, and improves the tracking precise and stability of rocket launcher.

Research on Torque Control of Servo System Load Simulator Based on Grey Prediction Fuzzy-PID Controller

WANG Li， QIAN Lin-fang， GAO Qiang， GUO Qi

2012, 33(11):  1379-1386.  doi:10.3969/j.issn.1000-1093.2012.11.017

Asbtract ( )   PDF (1016KB) ( )  

References | Related Articles | Metrics

In order to restrain the extra torque and improve the loading precision of servo system load simulator, a fuzzy-PID torque controller based on grey prediction was proposed. According to the variation trend of the data measured by sensors, the grey prediction model predicted the future values of loading torque circularly, and took those prediction values as the operation basis of the torque controller. When the error was large, the controller performed a switch control; while the error was small, the controller performed a fuzzy-PID control. Meanwhile, a flexible factor depending on error was introduced to adjust the universe of the input variable dynamically and enhance the control ability of the fuzzy controller. The simulation and experiment results show that, compared with the traditional PID control, the proposed control strategy can reduce the extra torque by about one half, and therefore, it can be used to control the dynamical loading of servo systems.

An Improved Method for Rapid Ambiguity Calculation Using Single Frequency GPS Receiver

PANG Chun-lei, ZHAO Xiu-bin， LU Yan-e， YU Yong-lin， YAN Yu-guo

2012, 33(11):  1387-1392.  doi:10.3969/j.issn.1000-1093.2012.11.018

Asbtract ( )   PDF (970KB) ( )  

References | Related Articles | Metrics

Aimed at ill-condition observation matrix in precise rapid positioning, a new algorithm for ambiguity resolution using single frequency GPS receiver was studied. According to the principle of Tikhonov regularized algorithm and the perturbation theory of singular value decomposition, an improved algorithm for singular value decomposition (SVD) was designed, and then the non-stabilization on regularized matrix caused by little singular values was avoided. The improved regularized matrix was educed, the construction method was established on the basis of analyzing the characteristics of ill-condition matrix, and it was proved theoretically. The experiment results indicate that the improved algorithm is more effective to improve ill-condition observation matrix, comparing with conventional LAMBDA algorithm and Tikhonov regularized-LAMBDA algorithm; the more precise floating-point and fixing-point solutions can be acquired quickly and credible.

Service Selection of Network Simulation Task Community Based on Improved Particle Swarm Optimization Algorithm

SUN Li-yang, LIN Jian-ning, MAO Shao-jie, LIU Zhong

2012, 33(11):  1393-1403.  doi:10.3969/j.issn.1000-1093.2012.11.019

Asbtract ( )   PDF (1082KB) ( )  

References | Related Articles | Metrics

As one of new application requirements in network simulation, to dynamically integrate the distributed various services in network to form a new simulation task community (STC) which meets the needs of different users has become current research focus. This paper presents a simulation service selection method based on the particle swarm optimization. The traditional particle swarm algorithm has some shortcomings that may easily fall into local optima and have slow convergence rate. We design a dynamic inertia weight strategy and a selectable method of mutation. The algorithm can improve the convergence speed not only, but also avoid falling into local optimum. Finally, some typical functions are chosen to test the algorithm. And the results show that the algorithm can select services feasibly and effectively for STC.

Simulation on Mechanical Properties of Composite Directional Pipe

LI Pei-zhen， LI Zhi-gang

2012, 33(11):  1404-1408.  doi:10.3969/j.issn.1000-1093.2012.11.020

Asbtract ( )   PDF (1181KB) ( )  

References | Related Articles | Metrics

Considered the influence of the flexible deformation of composite directional pipe on the movement of rocket, a mechanical model was established by using visual prototype, and the simulation principle and algorithm were discussed. Some useful data,