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1999 Vol. 25, No. 6

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Overview of Adaptive Structures
Xia Renwei
1999, 25(6): 623-628.
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The technical motivation that stimulated the initial research in adaptive structures was the goals of attenuating and controlling the vibration motion and maintaining the shape of large flexible space structures,which can be adapted through automatical response to internal or external stimulations by direct integration of actuators,sensors and controllers into the load-carrying structures.It is expected that adaptive structures will play an important and irreplaceable role in meeting the performance requirements of future large spacecrafts. An overview of the technology related to adaptive structures is presented in this paper. Included are the development background, definition and constitution, basic concept and theory, as well as critical technologies of adaptive structures.
Study of System Simulation of Satellite Constellation
Xiang Kaiheng, Xiao Yelun
1999, 25(6): 629-632.
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A study of system simulation of satellite constellation is introduced. System simulation would play an important role in Computer Aided Design (CAD) of satellite constellation. From the point of view of orbital dynamics, the concept and requirements of system simulation of constellation are presented, the mathematical models for system simulation are established, the hierarchy and architecture of software implementation are studied. At last, a program accomplished by the authors for system simulation of constellation is briefly introduced. Simulation results show that the system simulation software are beneficial to optimization of constellation design, verification of constellation control strategies, etc.
Adaptive Attitude Control of Extra-Vehicular Activity
Han Chao
1999, 25(6): 634-638.
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Extra-Vehicular Activity (EVA) is one kind of aided devices for astronaut's acting out of the spacecraft. Because of the mass property uncertainties and variations, the attitude control of EVA is a nonlinear and time variant control system with the uncertain parameters. This paper presents the study for direct adaptive angular velocity tracking (AAVT) control of EVA with the command generator tracker (CGT) method. Based on the AAVT, an adaptive attitude control method of EVA is presented. Simulation shows that the adaptive control with CGT has good robustness. The tracking precision of angular velocity is 0.1 deg/s; precision of attitude control is 0.5 deg.
Pre-and Post-Processor Development Based on MSC/Patran and Applications of Structural Optimization System
Huang Hai, Tao Qian, Ke Wen
1999, 25(6): 639-642.
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Under UNIX environment and on MSC/Patran platform, a pre-and post-processor of structural optimization system is developed. The work is done with adding special commands and windows using the development tool PCL provided by Patran for the customization of MSC/Patran. The available modules of numerical computation are integrated and the engineering program system is finally formed. The pre-and post-processor of the system developed by above technique can keep the original powerful functions of the platform. Besides attracting users, it is easy to be developed. The practicability and efficiency of the system are showed with examples.
Research on Conceptual Design Supporting Concurrent Engineering
He Linshu, Wang Hongqi
1999, 25(6): 643-646.
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One of the crucial problems of CE (Concurrent Engineering) is conceptual design. Although MDO (Multidisciplinary Design Optimization) has had obvious progress, it does still not satisfy a variety of special requirements during conceptual design of products. In order to cope with the difficulties for forming an available scheme, an orthogonal design method based on the orthogonal table of statistics is described in this paper. The method can deal with multivariable, multiobjective, multidisciplinary synthetic problems. Since its adaptability and efficiency for many products, it is worthy to be further improved.
Study of a Practical and Efficient Structural Optimization Method
Zhang Yuzhu, Zhang Ya
1999, 25(6): 647-650.
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Original mathematical programming is approximated with quadratic programming which is solved by generalized multiplier method. The following approximating approaches are utilized: 1.Talor formula is used to condense the object function into a second order function in logarithmic form. 2.Duffin approximation is applied to condense constraints. At last, a example is testified and shows that this method is simple, feasible and efficient.
New Type Isolator Design Based on the Principle of Variable Rigidity
Sun Bing, Nie Jingxu
1999, 25(6): 651-654.
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On basis of variable rigidity principle,by combination of the advantages of rubber and metal vibration isolator,a composite structure isolator with special shape elastic element and damping amplitude limiter is designed.It has a characteristic of small compressibility, large damping, long life and fast heat transference as well as little environment affection. Theoretical analysis and experiment result indicate that the isolator can good insulate vibration, and isolation performance is stable.
Neural Network for Estimating the Main Parameters in Flight Vehicle Preliminary Design
Nie Rongmei, Xia Renwei, Chen Wangchun
1999, 25(6): 655-659.
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With neural network technology developed rapidly in recent years,three parameter estimating networks for total mass,lift coefficient and drag coefficient are respectively structured successfully that play an important role in flight vehicle preliminary design.The result shows that trained parameter estimating networks can give more accurate value than usual approximating functions.And,according to the characteristics of the data involved here,a modification has been made for promoting the accuracy of MBP algorithm.The simulating result proved that the modified MBP algorithm can work more effectively.This method can be used in other product's preliminary design of machinery,aeronautics and astronautics.
Design Considerations for Anti Tactical Ballistic Missile
Chen Wanchun, Zhao Lihong, Liu Jiaqi
1999, 25(6): 660-664.
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By use of direct trajectory optimization method,the selection of overall design parameters of an anti ballistic missile for a 1000km range ballistic target is discussed. The following factors are taken into account in our research: the variation of parameters of the solid rocket motor,the constrains to the collision angle required by the seeker side window,the constrains to the maximum Mach number and the terminal velocity for the consideration of ablation problem,the selection of initial flight path angle and time of launch and other considerations such as the maneuver load limit and gravity compensation. It is found that a very large interceptable region can be obtained by properly selecting the design parameters and by use of the hybrid rocket motor.
Decision and Information Fusion in Multiple Air Combat
Sheng Wei, Tong Mingan, Wang Honglun, Li Jianxun
1999, 25(6): 665-667.
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Decision and information fusion in multiple air combat means regarding every side in air combat as a whole system. It can overcome the shortage of traditional ideals of multiple air combat——every plane fighting for itself, no communication and cooperation among the friendly planes. This method combines the consulting and gaming theory with the practice situation of multiple air combat to form a model by choosing the suitable consulting model and the weights. The combating efficiency has been improved obviously.
Realization of Terrain Simulation in Research of Clobber Probability
Guo Qifeng, Zhou Tao, Guo Zhenhua, Zhou Huizhong
1999, 25(6): 668-671.
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Terrain numerical simulation is the prerequisite problem in study of terrain-following missile clobber probability by adopting digital simulation method. Three typical terrains are simulated using wave superpose method based on the work of full exploration of terrain model and its realization .Effect of wavelet number on simulation result is studied,the results indicate that satisfactory results can be obtained by selection of a certain wavelet number.This work is of great practical values to weapon system evaluation and clobber probability research.
Studies on the Overall Project Design of Missile
Guo Zhenhua, Dong Changhong
1999, 25(6): 672-675.
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The whole process of missile overall project design is described by an example of air-to-air missile design, and the flow-chart is showed for demonstrating the procedure clearly. The method for the project evaluation and the way to confirm the weights used in the project evaluation are introduced. Through the human-computer interaction, the missile overall project design will be completed on the computer better than the traditional design method. The results of air-to-air missile design show that the method is effective. Then some problems to which should be paid attention are pinpointed.
Experimental and Numerical Studies on Aerospike Nozzles
Liu Yu, Zhang Zhengke, Cheng Xianchen, Zhang Zhenpeng
1999, 25(6): 676-679.
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This paper presents the designing procedures of the wall contour of aerospike nozzle using characteristic method and a sample result; obtains the numerical results of viscous side nozzle internal flow field from transonic to supersonic flow,the Euler solution of the flow field along the plug wall and after the plug bottom,and summarizes the solid propellant test system simulating the working property of aerospike nozzles, experimental results and the main conclusions. Rocket engine with aerospike nozzle is a complex and challenging research direction. It will play important role in the development of a new generation reusable launch vehicle.
Direct Numerical Simulation on 2-D H2/O2 Mixture and Flow
Cai Guobiao, Zhuang Fenggan
1999, 25(6): 680-683.
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The present work uses high order accuracy compact difference scheme and composites the computer code for 2-dimensional compressible low velocity H2/O2 mixing flow evaluating with time growth. Computation for subsonic, transonic and supersonic H2/O2 mixing flow with Reynolds number being 400 and Mach number being 0.4 (upper part H2) and 1.57 (bottom part O2) has been done and obtained computation results. The computation results are analyzed and studied.
Model and Algorithm of Inverse-Problems on Fault Diagnosis for Propulsion Systems
Yang Erfu, Zhang Zhenpeng, Liu Guoqiu
1999, 25(6): 684-687.
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According to the requirements of study on fault diagnosis of large-scale liquid rocket propulsion systems, an inverse-problem model on fault diagnosis has been established and an algorithm to solve the model has also been put forward in this paper. The method is based on genetic algorithm (GA). After investigation on characteristics and difficulties of inverse-problems on fault diagnosis, the algorithm used for solving the inverse-problems is studied emphatically. Finally, an application example obtained from inverse-problem model by genetic algorithm is also illustrated, which demonstrates that the above-mentioned inverse-problem model and algorithm are sound and effective.
Transient Analysis of a Divert Thruster for Micropropulsion Systems
Zhang Guozhou
1999, 25(6): 688-691.
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In the past several years, the miniaturization of Liquid Rocket Propulsion Systems advanced tremendously. The advanced micropropulsion systems are characterized by the miniaturization, high pressure and fast response. For these micropropulsion systems, the mathematical models of components are derived and gathered together. For the divert thruster of micropropulsion system, the variation of the combustion chamber pressure during impulse working and the pressure variation during closing the divert valve are investigated and analysed. It provides a basis for research of the dynamic response of the whole micropropulsion system.
Numerical Investigation of Gas Dynamic Resonance Tube Heating
Liang Guozhu, Zhang Zhenpeng, Zhang Guozhou, Cheng Xianchen
1999, 25(6): 692-695.
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The heating phenomenon emerges in some conditions when a semi-open resonance tube is placed in a stream of gas. In this paper a numerical method based on one-dimensional nonstationary nonlinear Euler equations for an ideal and perfect gas is developed,and using MacCormack scheme,a physically explicable solution is obtained. It is shown that at the linear resonance frequencies the conditions are favorable for the formation and amplification of oscillating shock waves leading to heating of the gas in the end part of the resonance tube. Calculations of different driving gases and different tube configurations(cylinder and cone) also give valuable conclusions.The results of this paper tally with experimental facts or phenomena.
Design of Rocket Reaction Turbine for High Efficiency
Zhuang Yunan, Zhang Guozhou, Liu Zhongxiang, Wei Mo
1999, 25(6): 696-699.
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In order to gain higher specific impulse, the rocket turbines for the closed cycle are reaction turbines with a lower reaction in the rotating vanes. This rocket reaction turbine is characterized by lowest pressure ratio,highest load and low aspect ratio. Under the design conditions of large medium flow deflective angle in the turbine cascade, low aspect ratio and large relative rotor tip clearance, the positive attack angle design along the height of the vanes,varying load and varying loss design along the height of the vanes are adopted in order to minimize the secondary loss,the tip clearance loss and gain the high efficiency for the rocket reaction turbine.
Numerical Calculation of 3-D Flow in SRM Chamber
Xiang Hongjun, Fang Guoyao
1999, 25(6): 700-703.
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The 3-D unsteady turbulent flow is simulated in the chamber of solid propellant rocket motor with finocyl type grains. It is based on numerical solution of the 3-D time-dependent ensemble-averaged Navier-Stokes equations, incompressible fluid and a high Reynolds number k-εturbulence model. The SIMPLE calculation procedure is used to solve the discrete equations. Some special treatment has been applied to initial flow field. The computation results indicate that vortex motion act a space and time-dependent distribution in radial profiles of the chamber, and the mass addition from circumferential burning surface caused a non-equilibrium axial velocity distribution in the combustion gas field.
Effects of Interfering Factors on Performance of Liquid Propellant Staged Combustion Cycle Rocket Engine
Zhang Lihui Zhang Zhenpeng
1999, 25(6): 704-706.
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A nonlinear mathematical model for the static characteristics of a liquid rocket engine is presented. By using Newton method, the effects of each interfering factor on the parameters of liquid rocket engine are computed and analyzed. The analysis of the effects of the interfering factors on the engine parameters is carried out. The results obtained can be used for the analysis of rocket engine test results, the reliability analysis and the fault analysis, and also for bringing light to the variation of the engine parameters with various interfering factors.
Numeric Simulation of Plume Contamination in Vacuum
Du Jun, Wang Huiyu, Cai Guobiao
1999, 25(6): 707-710.
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The ejective flow produced by attitude control engine creates serious contamination to spacecraft, which can be classified, according to property, into mechanical,thermal, depository and chemical contamination. The calculation of this contamination is of referential value to the design and experiment of spacecraft on the basis of the numerical solution to vacuum plume flow field with DSMC method.
Experimental Studies on Pressure Regulator Characteristic
Dai Wuye, Ma Bin, Zhang Guozhou, Liu Yu
1999, 25(6): 711-713.
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An experimental system of pressure regulator characteristic is introduced.The experimental settings with their function and performance are described in detail.The operation process of regulator characteristic experiment is presented.The dada acquisition of this experiment system is introduced briefly.The method as well as software of calculating the regulator static characteristic is showed.A typical experimental result with its validation is given.
Observability Analysis of Strapdown Inertial Navigation System on Moving Base
Fang Jiancheng, Zhou Rui, Zhu Shiping
1999, 25(6): 714-719.
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The SINS error model of alignment procedure on moving base is established. The observability of SINS in-flight alignment is deeply studied and thoroughly analyzed by means of the observability analysis theory and method of PWCS. In this paper, at first the movements of base are divided into two kinds of straight motion and rotation, then the influence of various maneuver of the base on the observability of SINS alignment procedure is first analyzed respectively in detail, and it is pointed out that, in alignment process of SINS an moving base, whether the straight motion of base or the rotation can all enhance the observability of SINS. At last some valuable results are obtained, it lays down a solid foundation for study of the fast and accuracy alignment method of SINS.
New Kind of Energy-Spectrum Entropy Image Focusing Evaluation Function
Zhu Shiping, Fang Jiancheng, Zhou Rui
1999, 25(6): 720-723.
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To counter the selection and design of image focusing evaluation functions in the field of computer vision, the fundamental concept and characteristics of image focusing evaluation functions are introduced firstly. Then some kinds of current main image focusing evaluation functions (such as gray scale variation function, gradient function, image gray scale entropy function, frequency domain function) are analyzed. On the base of above discussion, a new kind of energy-spectrum entropy image focusing evaluation function is presented, and the corresponding mathematical formulae are also given. The theoretical foundation of this function is more sufficient than current other ordinary functions. Finally, the experimental results of energy-spectrum entropy function are compared with other functions, the result indicates that the energy-spectrum entropy function is more accurate, stable and reliable in the evaluation of the quantity of image focusing.
Modeling and Control of Magnetic Bearing System Using Neural Networks
Zhou Rui, Fang Jiancheng, Zhu Shiping, Shen Gongxun
1999, 25(6): 724-727.
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The principle and its approximative linear modeling of magnetic bearing system are given. The linear controller based on linear control theory and simplified modeling is developed, which results in the performance degradation and limitation of magnetic bearing system. The method of modeling and control of magnetic bearing system using nonlinear recurrent neural networks is studied,and the learning algorithm combined with the practical application of the magnetic bearing system is also developed. The proposed method restrains the effects of nonlinearity and uncertainty on the performance of magnetic bearing system,and has the ability of robustness,which improve the system performance greatly.
Fast Initial Alignment Method of Inertial NavigationSystem on Stationary Base
Fang Jiancheng, Zhu Shiping, Yu Wenbo
1999, 25(6): 728-731.
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The initial alignment of INS is a very important procedure. It is very valuable to the INS used in various weapon system and civil system that the best alignment accuracy is obtained in the shortest time. Because of the poor observability of INS on stationary base,the estimation of the azimuth error will converge very slowly in initial alignment by means of Kalman filter. A fast estimation method of the azimuth error is creatively proposed for the initial alignment of INS on stationary base. On the basis of the fast convergence of the leveling error,the azimuth error can be directly calculated.By means of this fast initial alignment method, the time of initial alignment is reduced greatly. The computer simulation results illustrate the efficiency of this method.
Integration of Digital Detecting Circuit for Closed-Loop FOG
Song Ningfang, Zhang Chunxi, Ma Yingjian, Zhang Weixu
1999, 25(6): 732-734.
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Integration and digitalization are two key factors leading to the engineering application and batch manufacturing of FOG. By considering the FOG's technical situation and the technique of semiconductor in our country,the research on integration and optimization of digital detecting circuit for the closed-loop FOG based on the fast DSP chips and large scale CPLD or FPGA chips is presented in this paper. Test result shows: the performance and reliability of integrated detecting circuit are improved as compared with the circuit based on the separated components.
In Situ Study on PZT Modulator in Open-Loop FOG
Yang Yuanhong, Zhang Weixu, Ma Jing
1999, 25(6): 735-738.
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The application characteristic of PZT fiber-optic phase modulator used in open-loop Fiber Optic Gyroscope (FOG) was analyzed theoretically. The open-loop FOG performance defection due to the variation of modulation coefficient and phase delay was studied. Two kinds of in situ measurement methods were designed, with which the temperature characteristic was tested and the temperature model was obtained with the least square polynomial fit method based on the data measured. The study shows that the open-loop FOG phase modulation coefficient KGP is linear with the temperature variation while the phase delay is quadratic in the experimental temperature range.
Study on Simulation Computer System in Software Reliability Testing Platform
Liu Dongyan, Shen Gongxun
1999, 25(6): 739-742.
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The structure and functions of SRTP(Software Reliability Testing Platform) consisting of main control computer and stimulation computer are introduced. On the basis of expansibility and universality,the study is concentrated on scheduling strategy and key implementation technology in simulation computer,such as real-time network communication,hardware driving method in Windows 98.In this paper,the new technique of graph task chain for task scheduling is proposed and how it can be applied to engineering is discussed.The practical results show that the technology is reliable,expansive and applied.
Development of the Prototype of High Speed Image Compression Device for Satellite
Cheng Zijing, Zhou Xiaokuan
1999, 25(6): 743-746.
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Hardware implementation of Multi Mode Adaptive Quantization Compression (MMAQC) algorithm for high speed image compression is investigated. Using pipeline and synchronization parallel arrays, the VLSI architectures for modeling, quantization and coding are proposed. The proposed hardware architectures are fast with low hardware complexity. Based on the architectures, a prototype of high speed image compression device for satellite is designed and manufactured with Field Programmable Gate Arrays. Test results show that at compression ratio of four, the processing speed of the device is above 1000Mbit/s, and the average PSNR of restored images is above 40dB.
Entropic Thresholding Method Based on Genetic Algorithm
Chong Jingsong, Zhou Xiaokuan, Wang Hongqi
1999, 25(6): 747-750.
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The method of entropic thresholding proposed by Kapur, Sahoo and Wong (KSW) is implemented using Genetic Algorithm(GA). Optimum parameters suitable for this algorithm are also given. KSW method has many advantages. However, it has weakness: it needs a great deal of computational time especially when computing multithreshold. So it needs to import optimization technique. Genetic Algorithm proposed by John Holland is a robust and adaptive stochastic searching method. Entropic single thresholding and multithresholding methods are all presented using GA. The results show that it can shorten the computational time compared with the classical KSW method.

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