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2003 Vol. 29, No. 8

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Design and realization of airport refueling automatic system based on DCS
Zhang Dahua, Qiu Lihua, Wang Zongxue, Chen Yuanfu
2003, 29(8): 659-662.
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In order to enhance the automatic level of civil airport refueling system, the principle and method of DCS (distributed control system) was applied to design and realize airport refueling automatic systems. According to the principle of "distributed control and centralized management", the system structure was divided into 3 layers: field equipments layer, direct control layer, and supervisory control and management layer. The main functions, the configuration of hardware, and the development of software, of each layer were summarized. The scheme has been successfully used in several airport refueling automatic systems. The practice indicates that these systems are steady, reliable, and have high automatic level.
Influence of ambient pressure on aerospike nozzle base pressure
Li Junwei, Liu Yu
2003, 29(8): 663-667.
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In order to understand the influence of ambient pressure on aerospike nozzle base pressure, the implicit NND(non-oscillation, no free coefficients dissipative) scheme was employed to solve 2-D laminar N-S equations. Aerospike nozzle flow fields under different CNPR (i.e. nozzle pressure ratio) without base secondary flow and with secondary flow of 1.4% mass flux rate were obtained. The result shows that with the increase of ambient pressure, base pressure also increases. But under closed wake, the increase is slow; under open wake, the increase is rapid and even the pressure fluctuates.
Pareto genetic algorithms for multi-objective optimization of aircraft conceptual design
Fang Weiguo, Shi Ruifeng
2003, 29(8): 668-672.
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Based on the Pareto optimal conception, a kind of MOGA(multi-objective genetic algorithms) seeking non-inferior solution set of MO problems was proposed, while the filtering of non-inferior solutions and the measure of fitness degree were discussed as an emphasis. The algorithm proposed was applied to a two-objective optimization of a hypothetical airliner conceptual design, where both the ratio of lift to drag in cruise segment and the useful load fraction were required to be maximized. The optimal solutions were analyzed and compared to the solution from uni-objective optimization using simple genetic algorithms. The research result demonstrates that MOGA possesses good application foreground for aircraft conceptual multi-objective optimization.
Study on GPS receiver autonomous integrity monitoring
Liu Zhun, Chen Zhe
2003, 29(8): 673-676.
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It proves that least square residual method is equal to parity space method in detection rule. A novel GPS(global positioning system) RAIM(receiver autonomous integrity monitoring) algorithm is presented. The results show that it provides high availability, low missed detection and sensitive to fault detection. It fulfils the need of the reliability of high precision guidance system. The approach using the barometer and receiving GLONASS(global navigation satellite system) signal to realize GPS RAIM when lacking satellite number-in-view is studied,and it has been demonstrated by simulation.
Application of tree classifier in the image diagnosis of the adhesive quality about the multi-layered structure
Zhang Jitang, Lu Hongnian
2003, 29(8): 677-681.
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When the adhesive quality in multi-layered structure (steel shell, under layer and insulation layer)which is used in the solid rocket motor is diagnosed,the resonance between the echoes is used to obtain the signal characteristics, i.e. delay time. Extracting the signal characteristics and recognizing the adhesive state is a pattern recognition process. The dichotomous branch tree classifier is designed to accomplish the pattern classification .The high quality diagnosis image is obtained.
Rate of initiation and propagation in electron beam curing of epoxy resins
Sui Gang, Zhang Zuoguang, Li Min, Li Fengmei
2003, 29(8): 682-685.
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The kinetic studies on electron beam (EB) curing of epoxy resins were made. The experimental results manifested that a second-order reaction is involved during the production of protonic acid deriving from radiation decomposition of diaryliodonium salts initiator and the decomposition kinetic constant is obtained. The rate of initiation and propagation for epoxy resin in acetonitrile solution has a rapid increase up to a maximum value, and then decrease.
Study on reaction rate and kinetic constant in radiation curing of epoxy resins
Sui Gang, Zhang Zuoguang, Li Min, Li Fengmei
2003, 29(8): 686-690.
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The kinetic studies on electron beam curing of epoxy resins were made in this paper. The kinetic characteristics of different epoxy resin in acetonitrile solution are explored. The propagation kinetic constant has no evident change at initial stage and begins to decrease after some conversion. While the termination reaction is reaction-diffusion-controlled throughout the reaction process, and the termination kinetic constant is decreased gradually. The reaction rate of radiation systems decreases with the increasing molecular weight of epoxy resin and the reaction rate of the sample with high polydispersity is higher at the same reaction extent. For the epoxy resin systems whose chemical structure of molecules is different, the reactivity of samples under radiation can be greatly affected by density of functional groups and space obstacle in molecular structures. The radiation system with a higher reaction rate can get to higher conversion during the radiation process.
Numerical investigation on heat transfer in an annulus between independently rotating cylinders with turbulent axial flow
Fu Debin, Ding Shuiting, Xu Guoqiang, Tao Zhi
2003, 29(8): 691-695.
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Heat transfer in the air gap of two rotating cylinders was numerically studied, based on the mixing length turbulent model. Temperature field of annulus, temperature distributions and heat transfer coefficient distributions on inner cylinder surface were calculated and compared with experimental results. The results show that the mixing length turbulent model is applicable for the simulation of heat transfer in the annulus between independently rotating cylinders.
Application of an improved importance sampling method in mechanisms reliability
Zhao Guangyan, Zhang Jianguo
2003, 29(8): 696-699.
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The Monte Carlo importance sampling method together with response surface, which was used to calculate the mechanisms reliability, was studied. Based on the method, a reliability analysis software for aircraft structural systems was developed, and a case of a elevator control mechanisms was presented to illustrate the method. The analysis results show that this method can enhance the mechanisms reliability analysis efficiency.
Studies on infrared camera using in heat transfer experiments
Wen Jie, Zhao Guilin, Tao Zhi, Peng Hui
2003, 29(8): 700-703.
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The possibility of using infrared camera in heat transfer experiments was discussed and the various influential factors was analysed, such as the radiation ratio of materials,roughness of surface and the transmissivity of special materials for infrared ray transmission. The studies indicate that the infrared camera can be used in heat transfer experiments, but need to determine various influential factors according to the special experimental cases.
Model of temperature-controlled air supply duct of a kind of fighter ECS based on MATLAB
Yao Hongwei, Wang Jun
2003, 29(8): 704-707.
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The configuration and working principle of temperature-controlled air supply duct of a kind of fighter ECS (environmental control system) are detailedly introduced. Based on the mathematical model of components, the dynamic simulating model of entire ECS is established by using simulink, one of toolboxes of MATLAB. With the use of the model, the effect of every parameter of the air supply duct, such as the backing pressure of turbine, regulating range of the pulse width modulator as well as the parameters of electric motor, on the dynamic performance of the ECS is analyzed. Regulation of these parameters can improve the dynamic response performance of the system. The conclusion is helpful to design and optimization of the temperature-controlled air supply duct.
Simulation technology study of the high/low temperature environmental simulation system based on MATLAB
Dong Sujun, Feng Zhenggang, Wang Jun
2003, 29(8): 708-712.
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A simulation scheme based on the platform of MATLAB software for the high/low temperature environmental simulation system (H/L TESS) is introduced and illustrated by an example of simulation project. Fist the MATLAB simulation models library of the system is built for systematic simulation purpose with the individual equipment as basic module, the equations such as state equation, mass continuous equation, energy conservation equation, momentum conservation equation, etc. as the foundation, and the MS-Function and masked block as the basic method. Then the simulation models of a real environmental simulation system are set up using the models of this library. And last the application software of the H/L TESS is developed by the technology of MATLAB graphics, ActiveX data transfer and dynamic data transfer. It is approved that the approach can effectively carry on planning and design of system simulation research and give both the research and the application software a good continuity and expansion.
Displacement ventilation system using solar energy desiccant cooling technology
Zhang Pong, Wang Jun
2003, 29(8): 713-716.
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Based on the development trend of the current air conditioning, a new mode of ventilation-displacement ventilation is introduced, not only the principle of this ventilation system but also the thermal comfort conditions of the ventilation system combined with cooled ceiling.According to the current situation of energy crisis and ecological environment deterioration, a displacement ventilation air supply system is presented based on solid desiccant cooling cycles using solar energy, and the properties of the combination of the two systems are expounded in terms of energy conservation, environmental protection and thermal comfort ambient creation.
CSCW application in air traffic management
Zhao Yifei, Wu Zhe
2003, 29(8): 717-721.
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In order to increase the cooperation efficiency and decrease errors of flight release in air traffic management, theories and technology of CSCW(computer supported cooperative work) have been introduced and an applicable CSCW system for flight release cooperation has been designed. Practice has shown that the cooperation efficiency has raised, workloads of staff have decreased and less errors happen due to use of the CSCW system for flight release cooperation. The result has also proven practical value of the system.
Application of DSP in secondary surveillance radar signal simulator
Zhang Yongjie, Li Shaohong
2003, 29(8): 722-724.
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The design idea and fundamental structure of a SSR(secondary surveillance radar) signal simulator are presented. The structure and characteristic of TMS320F206, a kind of 16-bit fixed-point DSP(digital signal processor), are introduced and the function of the DSP in the data-exchanging, control of the system and the process of the I/O port data is discussed in detail. The problems that should be paid attention to in the process of system-debugging are also presented. The expected result has been acquired after the debug of the SSR signal-processing unit.
Study on curl-based streamribbon visualization
Hu Xing, Yang Guang, Dong Haitao
2003, 29(8): 725-729.
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Streamribbon visualization,one of the important techniques for CFD(computational fluid dynamics) vector fields visualization,was investigated. On the basis of the analysis on existing algorithms regarding streamribbon generation, the stress was laid on the streamribbon generation algorithm based on the curl in vector fields. The implementation of this algorithm is explained in detail. In order to solve one of the key points in the algorithm, principles of differential calculus on compound functions was introduced to calculate the curl in data sets of three-dimensional steady vector fields with irregular structured grids. The streamribbon generation algorithm based on curl is of lower complexity, as well as is of higher robusticity and tractability. The resulting visualization images of streamribbon conduce to the study on the vortices in flow fields.
Sensors parameters modification integrated vehicle navigation and location system
Gao Peng, Fu Li, Fan Yuezu
2003, 29(8): 730-733.
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Composing of GPS(global positioning system)/DRS(dead reckoning system)/MM(map matching)integrated vehicle navigation and location system and vehicle positioning algorithm were expatiated. Kalman filter and non-Kalman filter algorithm for sensors parameters modification was represented, and the problem of sensors parameters drift was resolved. Simulation indicated good modification result.
Robust adaptive interference rejection in DS/FH hybrid system
Liu Jicheng, Shao Dingrong, Li Shujian
2003, 29(8): 734-736.
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According to robust estimator theory, an adaptive filter based on generalized M estimation was used to reject partial band interference in DS/FH hybrid communication system, and the robust adaptive algorithm was deduced. The performance of two M estimation functions (Huber function and Tri-weight function) which are widely used in M estimation was also compared. Monte Carlo simulation results indicate that the performance of DS/FH system using robust adaptive filter is improved remarkably in nonstationary interference environment ,and the performance of Tri-weight function excels the Huber function's obviously.
Application research on thermal analysis software of electronic systems
Fang Zhiqiang, Fu Guicui, Gao Zexi
2003, 29(8): 737-740.
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The temperature field of a product can be picked up to optimize the design and improve the reliability by the technology of thermal analysis in the phase of design. Based on the characters of thermal analysis software, some problems in their application are discussed. With a simple example, the whole process of thermal analysis is presented, and several application solutions are given. The results show that if the main problems are solved correctly, a good thermal analysis will be gained to meet the demands of engineering.
Kind of fast Hough transform used in line detection
Qiu Liwei, Song Zishan, Shen Weiqun
2003, 29(8): 741-744.
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Hough transform is a widely used algorithm in computer vision and pattern recognition. However, the tremendous computation required by Hough transform impedes it used in real-time applications. The standard Hough transform used only the information of a single non-zero pixel, which causes the huge computation. The relationship between two pixels is concerned in the presented scheme. A line parameter is obtained from the coordinates of two pixels, so the computation is deceased distinctly. The testing data shows that the fast algorithm is faster 10~100 times than the standard one in a same platform,while the precision is kept.
Integrated reliability evaluation of development test data based on AMSAA model
Du Zhenhua, Zhao Yu, Huang Min
2003, 29(8): 745-748.
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Based upon the AMSAA model which has been widely used in engineering,a method of defining the time environmental conversion factor was proposed through optimization process, which made full use of the failure data from the same kind of products or the similar products in their development tests, and it made all the development test items into a few typical environment stress types in case the development test include more items, at last a method of defining the MTBF(mean time between failures) confidence interval values of the product in its development stage was given. The research result indicates the method is reasonable and feasible, it can satisfy the precision requirement in engineering.
Application of L-D factorization in calculating inverse in federated filter
Xiang Zheng, Fu Li, Fan Yuezu
2003, 29(8): 749-752.
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How to correctly calculate the inverse is one of the most important processes in federated filter. The precision of its result and time it will consume would decide whether the whole filter can work properly. The result of digital simulation illustrate that applying L-D factorization which is famous in matrix theory into federated filter to get the correct result of inverse can not only improve the speed and precision of algorithm but meliorate its error toleration.

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