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2003 Vol. 29, No. 1

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Simulation Platform Based on HLA for Air Defense Missile Weapon System
Zhang Yuhong, Hu Yahai, Peng Xiaoyuan, Feng Qin
2003, 29(1): 1-4.
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A synthetic simulation platform including virtual reality technology based on high level architecture is introduced. The platform is used to support air defense missile weapon system simulation. The structure and development process of the platform are presented. The related key technologies for constructing and developing this system, such as high level architecture, FEDEP process model, Hierarchical Software Architecture, computer generated forces, object-oriented modeling and collision detection based on bounding boxes, are also discussed in detail.
Realization of a Programmable Radar Echo Simulator Based on PCI Bus
Huang Zhigang, Liu Zhongkan, Wan Guolong, Shan Dongmei
2003, 29(1): 5-8.
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To improve the performance of current radar echo signal simulators, a scheme was advanced with computer PCI bus-organization, high speed FIFO and D/A. With the realization of this scheme, the simulator exhibits a data updating speed as high as 8 MHz and a signal conversion speed as high as 73 MHz. The use of FPGA technology made the system parameters programmable and able to change its structure expediently to adapt different types of radar. Through signal simulation output of synthetic aperture radar, the scheme was proved to be feasible. The operation of a sample machine was shown to be reliable and able to meet the needs of high-resolution image simulation.
Novel ICT Scan Mode and Its FBP Reconstruction Algorithm
Fu Jian, Lu Hongnian
2003, 29(1): 9-12.
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It is well known that Industrial Computed Tomography (ICT) is hampered by the matter of time to acquire an image severely. A scan concept called RR (Rotation and Rotation) was argued to save the scan time of large components ICT testing with TR(Transverse Rotation). Its reconstruction algorithm based on filter back-projection algorithm was presented. The validity of the algorithm was proved by computer simulation results. Analysis indicated that the scan speed can be improved at least three times, compared with that of TR limited by the same testing conditions.
Genetic Algorithm for the Scheduling of Public Traffic Vehicles in ITS
Teng Jitao, Zhang Feizhou, Li Yaopeng, Fan Yuezu
2003, 29(1): 13-16.
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Advanced Public Transportation System(APTS) is very important for the development of the subsystems of an Intelligent Transportation System (ITS). Vehicle Scheduling is a key technology of APTS. To improve the intelligence of vehicle scheduling, a new Genetic Algorithm(GA) based method for intelligent scheduling of public vehicle is proposed, with the minimum cost as the objective function. Factors explicitly considered in this paper include vehicle assignments, timing, operating efficiency and resource usage. An optimal scheduling scheme is produced by using genetic operator including selection, crossover and mutation. At the same time, two kindsof crossover are compared. Simulation result shows that the GA based method for vehicle scheduling is feasible, advanced and efficient.
Design of Test Software in Base Station for Navigation  under Windows Environment
Zhao Qi, Zhang Xiaolin
2003, 29(1): 17-19.
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A model of test software in pilotless helicopter base station for navigation is introduced. Design of test software for navigation is discussed. The software is based on Windows platform. It has a visual and self-contained visualization interface. One of the characteristics is easy and simple to operate. It has been tested successfully for many times in navigation control system of pilotless helicopter. The result meets the demand of flight.
Method for Fatigue Test of Aircraft StructuresConsidering Corrosion Influence
He Xiaofan, Liu Wenting, Jiang Dongbin
2003, 29(1): 20-22.
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Considering the influence of corrosive environment, a valuable method for fatigue test of aircraft structures at room temperature and in the air is presented. The service process of an aircraft is simplified into pre-corrosion under the ground environment and corrosion fatigue during flight, and corrosion influence coefficient curves of aircraft structures are obtained. According to the damage equivalent principle, the fatigue life indexes of aircraft structures at room temperature and in the air are deduced based on the designed fatigue life index and average flight time per year under corrosive environment, so the testing object life can be determined.
PostStall Maneuver Control Law for Aircrafts with New Control Configuration
Zhang Ping, Wang Dong, Chen Zongji
2003, 29(1): 23-26.
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A post-stall maneuver control law for aircraft with new control surfaces and trust vectoring control is proposed. The air dynamical data table is operated by minimal mean-square value of the error between the air data and the combined continued functions. The 6 freedom nonlinear dynamical equations of the aircraft are predigested at static operating points by extended linearization which still possess nonlinear characters. The control laws of the inner closed-loop system and post-stall maneuver are obtained through using symbol operations design. Simulation result shows that the control law is effective for the post-stall maneuver design of modern aircrafts.
Transfinite Interpolation Grid Generation with the Application of B Spline
Yu Rixin, Zhu Ziqiang
2003, 29(1): 27-30.
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A grid generation method by applying B spline curve lines and surfaces to transfinite interpolation approaches is suggested. Numerical results demonstrate that detailed information about geometry shape can be included and so the method can be used to different complex geometries. Discussions are also made about how to adjust the boundary tangential vectors and the inner-point-array which forms a skeleton of the final grids. The results show that this method can generate high quality grids.
Numerical Simulation Method of Acoustic Fatigue of Composite Structures
Du Sanhu, Li Zailiang, Yang Jialing
2003, 29(1): 31-34.
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Acoustic fatigue of composite structures concerns many researchers. Numerical simulation is often used to deals with this problem. In this paper, BEM is used to simulate the dynamic response of composite structures, and a numerical simulation method of acoustic fatigue of composite structures is presented. The results can provide references for forecasting acoustic fatigue life of composite structures.
Modeling and Dynamics Analysis of LiquidFilled Flexible Spacecraft
Jia Yinghong, Xu Shijie, Nie Runtu
2003, 29(1): 35-38.
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This paper deals with the modeling problem of a spacecraft consisting of a liquid-filled rigid platform and some flexible appendages. The spacecraft is modeled by using the Kane's equations. Hybrid-coordinate and spring-mass equivalent model for liquid sloshing are adopted in the modeling. With two-class appendages, the multi-body open-chain dynamic model can be applied more universally. Simulation results on a sample of tracking and data relay satellite were given to show the validity of the proposed model.
Effects of Geometry Parameters and Flow Parameters on Drag Coefficient of Upswept Afterbodies
Kong Fanmei, Hua Jun, Feng Ya'nan, Qiu Dong
2003, 29(1): 39-42.
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The flows over upswept afterbodies were investigated by a numerical method based on 3D compressible N-S equations, in order to study effects of geometry parameters and flow parameters on drag coefficient of upswept afterbodies. The results showed that the pressure drag coefficient increases rapidly with increasing upswept angle and contraction ratio respectively, and with decreasing forebody incidence. The friction drag coefficient increases with increasing afterbody fineness ratio and decreasing Reynolds Number. The more the afterbody flatness, the more the pressure drag. The wave drag coefficient also increases with increasing upswept angle at transonic speed.
Digital Interface for OpenLoop FOG
Yang Yuanhong, Zhang Weixu, Jiang Xinliu
2003, 29(1): 43-45.
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To improve the performance of open-loop fiber-optical gyroscope (FOG), a mathematical model was presented to get its linear digital output. Based on this model, a digital interface was designed, which is a micro-control system consisting of gain control-able A/D converter and control software and able to auto-range and convert analog output to linear digital output. Experimental study was also made with an all polarization-maintain open-loop FOG. The results showed that, with using the above interface, the nonlinearity of FOG can be effectively reduced.
Experiments on Performance of a Molecular Sieve Oxygen Concentrator System
Sun Bin, Xiao Huajun, Yuan Xiugan, Qian Guocheng
2003, 29(1): 46-49.
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The prototype of a molecular sieve oxygen concentrator system (MSOCS) was developed, on the principle of PAS. Various intake pressures,output flow of MSOCS, altitude pressure and the environment temperature tests were tested to analyze its performance of generating oxygen. The results showed that the concentration of oxygen generation of the MSOCS increases with increasing the intake pressures and altitude, and decreases with increasing output flow of MSOCS. The gradient rate and the environment temperature make no effects. The performance of generating oxygen meets the physiological requirements for the system engineering.
Rectification of Imaging Device Defections in Real Time Radiographic Inspection
Du Jian, Wei Dongbo, Lu Hongnian
2003, 29(1): 50-53.
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Converter screen and CCD camera are the main imaging devices in real time radiographic inspection. Their defections are important factors affecting image quality. Based on experimental results, formation and characteristics of these defections were analyzed, a new mathematic model and a rectification method based on gray scale compensation were presented. It was indicated through experiments that this method is efficient in the rectification of the imaging device defections, with the least loss of useful information.
Experimental Studies on GasOxygen/Alcohol MultiPipe Igniter
Wang Yibai, Liu Yu, Qin Lizi, Ma Bin
2003, 29(1): 54-58.
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Multi-pipe synchronous ignition technique is one of the key techniques of aerospike engine. Design and experiments of a gas-oxygen/alcohol multi-pipe igniter were introduced. The key factors influencing multi-pipe ignition were studied, which include propellants mixture ratio, time of igniting, material and geometrical size of the pipe, methods used to cool the igniter, and oxygen supply combustion. In addition, ignition methods at high altitude were also investigated. On the above basis, parameters of the igniter were determined, multi-pipe synchronous ignition was realized.
Dynamic Characteristics Calibration and Dynamic Performance Improvement of Infrared Carbon Dioxide Sensor
Wu Xiaoli, Zhang Guangjun
2003, 29(1): 59-62.
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An experimental method was presented to calibrate dynamic characteristics of an infrared carbon dioxide sensor. A dynamic mathematic model of infrared carbon dioxide sensor was established. The design process of the dynamic compensation filter was given, and the various factors influencing the compensatory effect were discussed. To reduce the operation time and to improve the response characteristic of the sensor, a method of converting difference equation to recursive arithmetic was adopted. Experimental result showed that the application of the dynamic compensation filter can effectively improve the dynamic characteristic of the infrared carbon dioxide sensor.
Study on Integrated Knowledge Model of Product Conceptual Design in CPC Environment
Zeng Lingwei, Deng Jiati
2003, 29(1): 63-66.
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In order to emphasize the position of supply chain in conceptual design phase and support the development of CACD systems, this paper provides an integrated CORE model to represent the conceptual product knowledge by referencing the software component techniques. Based on the integrated model, a prototype system to support conceptual design in CPC environment is developed.
Analysis on Response of Straight Tube CoriolisMassFlow Meter under Pulsating Flow
Fan Shangchun, Song Minggang
2003, 29(1): 67-71.
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The measurement error of Coriolis mass-flow meter is based on the vibration characteristics of the elastic tube of flow meter. In this paper, the influence of pulsating flow on performance of Coriolis mass-flow meter is analyzed, with the straight tube Coriolis mass-flow meter as the investigated object. The mathematical model of vibration of straight tube Coriolis mass-flow meter under pulsating flow is established. By making use of Galerkin method, the model is converted into a coupled multi-degree system under combined parametric and forcing excitation. Multiscale method is used to analyze qualitatively the discrete multi-degree system, the main vibrational components of the tube under pulsating flow are given, and thus the mechanism of action of pulsating flow to Coriolis mass-flow meter is shown clearly. Most of conclusions obtained here have been testified by experiments that were reported in the published papers. The conclusions are helpful to further investigation and application of Coriolis mass-flow meter.
SMA PseudoRubber Metal and Its Application in Vibration Control
Yan Xiaojun, Li Haiyan, Nie Jingxu
2003, 29(1): 72-75.
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By virtue of the superelasticity of Shape Memory Alloys(SMA) characterized by its hysteresis stress-strain curve, SMA pseudo-rubber metal damping units were developed and evaluated. On the above basis, a new type of SMA damper was designed and tested. It was shown that SMA damper possesses greater recoverable deformation, larger bearing capacity, and higher damping capacity, which make the SMA damper quite potential in passive vibration control, especially in random case.
NonLinear Filtering Method for Emissivity Correction ofPCB Infrared Thermal Images
Wan Jiuqing, Li Xingshan
2003, 29(1): 76-78.
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In the diagnosis of Printed Circuit Board (PCB) based on infrared radiation, emissivity correction must be performed on the thermal image to retrieve the true temperature distribution on the PCB surface. Taking the measured PCB surface temperature as a combination of its true temperature distribution and its emissivity distribution, a non-linear filtering method was proposed to separate the true temperature from this combination based on the differences in the continuity of these two contributions. As a key step of the proposed method, the wavelet implementation of discontinuities detection in thermal image was also discussed. Experimental results indicated that the true temperature distribution can be estimated precisely by the proposed method. It is also shown that the proposed method can be used in other applications such as heat source recognition on PCB infrared thermal image and emissivity estimation of unknown materials.
Method of Correcting INAS Error Based on LandmarkImage Messages
Chen Dazhi, Zhang Guangjun
2003, 29(1): 79-82.
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A method of correcting INAS error based on landmark-image messages is described, emulating results are presented. Using landmark-imaging system on the photoelectrical platform, the position of a plane can be worked out through landmark-image detecting, image transforming, matching orientation and coordinate transforming. Comparing this position with the coordinates received by INAS, the flight-path error of the plane can be calculated, accordingly the error of INAS can be corrected.
Modified MPS Method for Nonlinear Dynamic Problems
Guo Jun, Tao Zhi
2003, 29(1): 83-86.
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A modified moving particle semi-implicit (MPS) method was presented. Neighbor interaction models for differential operators are presented, without the use of ghost nodes to deal with boundary conditions. The performance of the proposed method was demonstrated by solving Burgers's equations. It was shown that the results using spline function as kernel without ghost nodes agree well with those with ghosts,and both results coincide with exact results or other existing solutions. It was also found that for 1D problems smooth weight functions perform better than non-smooth ones, while for 2D problems the effect of weight function's asymmetry near boundaries is negligible. This method was demonstrated to be quite straightforward, simple and easy to code.
Early RubImpact Fault Diagnosis Based on Wavelet Packet Decomposition
Song You, Liu Zhongkan
2003, 29(1): 87-90.
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Rub-impact signal detection between rotor and stator is investigated. The features of no rub-impact and early rub-impact are analysed based on the wavelet packet decomposition, which is sensitive to the singularity of signal and able to offer a richer resolution in frequency band than wavelet decomposition. Results show that the wavelet packet decomposition can be used to detect rub-impact signal effectively, and the localization of rub-impact faults can be realized with the present method.
Design of MotorDrive Load Simulator with Small Torque Outputs
Ren Zhiting, Jiao Zongxia
2003, 29(1): 91-94.
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Motor-drive load simulator with small torque outputs was designed, its stability and dynamic performance were analyzed. Based on an introduction to the structure and principle of electrical loading system, a mathematical model of the system was put forward to analyze and to simulate its stability and anti-jamming. By including multi-feedback and feedforward in the system and using control methods to control DC-motor, improved performance of the system was obtained. Simulation results indicated that the performance of the motor-drive load simulator is as good as that of the electro-hydraulic load simulator in the range of small torque.

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