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2009 Vol. 35, No. 8

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Requirement characteristics of low-aspect-ratio combat flying wings- roll axis control power
Wang Lixin, Li Lin
2009, 35(8): 909-912.
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The roll axis control power of low-aspect-ratio flying wings were assessed based on the criteria for Class Ⅳ aircraft presented in MIL-STD-1797A. The relationship of the roll performance requirement and the roll axis control power requirement was provided. Low-aspect-ratio flying wings need more roll axis control power with the same roll performance requirement, because of the all-wing configuration and the lager rolling moment of inertia. Without the vertical tail's contribution, the static lateral stability and control side force of the flying wing are less than those of the conventional combat aircraft, and with the application of innovative control effectors and the control allocation technology, low-aspect-ratio flying wings can achieve the decoupling control. As a result, the roll axis control power requirements of the flying wing for takeoff and landing in crosswinds and for asymmetric loading, have a lot of new characteristics in contrast with those of the conventional-configuration aircraft.
Application of Gurney flap on certain target drone
Zhao Yuanli, Zuo Linxuan, Yu Dongsheng, Wang Jinjun
2009, 35(8): 913-916.
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Experiments of Gurney flap on aerodynamics of a certain target drone were conducted in wind tunnel, the height of Gurney flap is in the range of 0.83%c~4.2％c(c—root chord length of target drone wing in the experiment). For the target drone without sideslip, Gurney flap could enhance lift at medium and small angles of attack, and decrease the angle of attack where lift to drag ratio reaches maximum value. Meanwhile, besides of the 4.2%c Gurney flap, the others could increase the lift to drag ratio and the maximum lift to drag ratio. For the model with sideslip, the corresponding aerodynamic performance is similar to that without sideslip in longitudinal direction. However, in yaw and rolling directions, rolling moment increases with Gurney flap height, and yaw moment increases too when the Gurney flap height is in the range of 0.83%c~ 3.3%c, but the yaw moment decreases abruptly when Gurney flap height is 4.2%c. There exists the optimum Gurney flap height for improving the target drone aerodynamics, Experimental results show that it could increase the lift and the maximum lift to drag ratio with little variation of the moments in three directions when the Gurney flap height is 1.7%c.
Route planning method for multiple vehicles coordinated target assignment
Wei Tietao, Qu Xiangju
2009, 35(8): 917-920.
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Multiple vehicles coordinated target assignment is the key problem to improve the efficiency of team fighting in the mission of multiple vehicles attacking multiple target regions. A route planning method for this problem was presented with consideration of the differences in vehicle ability, cooperation mode and the abrupt change of the battle field situation. Based on the evaluation of vehicle residual ability, a mathematical model of multiple vehicles coordinated target assignment had been built. The target assignment schemes were chosen by constraints on the vehicle residual ability, then the integrity of the military strength was ensured. The final simulation results of this model show that a stronger adaptability for abrupt change of mission objective can be gained.
Autopilot design for missile controlled by lateral thrust/aero force using combined optimal/classical approach
Xing Lidan, Chen Wanchun, Yin Xingliang
2009, 35(8): 921-924.
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To design the autopilot of the missile controlled by both lateral thrust and aerodynamic force, an approach utilizing the combination of optimal control and the frequency analysis in classic control was proposed. The autopilot structure and the gain values were obtained according to optimal control, and the frequency analysis was used to determine the weighting parameters in objective function, to make sure the robustness of the system. Then the simulation results were compared with the traditional method obtained, it shows that the system response becomes faster and a litter more overshoot appears when using the autopilot bought out, the robustness of the system is also indicated.
Hidden-removal method of perspective drawing based on constrains between lines and junctions
Mao Xia, Shen Wei, Zhao Xingyuan
2009, 35(8): 925-928.
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It makes a significant sense to obtain the 3-D information of the building correctly either in martial and civilian field. A method to remove the hidden lines and junctions of perspective drawing was proposed. Firstly, the visibility judgment of each model surface was made using the plane formula and geometry method. Secondly, the boundary line set were generated, which come from the projection calculating to get the perspective drawing and line reconstructing to get the lines needed. Finally, the hide degree inspection according to the relationship between lines and junctions of 3-D wire-frame model were checked, from which the visibility decision of the line was determined. This arithmetic uses the simple data structure to reduce the computational amount. The experimental results show the validity of the model and the effectiveness of the algorithm. The results of performance assessment also provide a new method and supporting means for hidden-removal of the topographic features.
Driver fatigue prediction with eyelid related parameters by support vector machine
Hu Shuyan, Zheng Gangtie
2009, 35(8): 929-932.
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Various investigations show that drivers- drowsiness is one of the main causes of traffic accidents. Thus, countermeasure device which should be able to predict the accidents accurately with low ratio of false alarms is currently required in many fields for sleepiness related hazard prevention. Drowsiness prediction was conducted by support vector machine (SVM) with eyelid related parameters extracted from the electrooculography(EOG) data collected in a driving simulator. 25 sleep-deprived subjects which hit the rumbles while driving in the experiment were selected based on the karolinska sleepiness scale (KSS) to make sure they were alert as they started driving and sleepy when the hits occurred, and then they were divided into training set including 20 subjects and validation set including the other 5 subjects. The validation results show that the hits can be successfully predicted at least five minutes ago by our SVM model.
Analysis of wake pattern and vortex evolution in flow past circular cylinder
Dong Shuangling, Wu Songping
2009, 35(8): 933-937.
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In low-Reynolds-number flow passing circular cylinder, fluid experiences a relatively complex process,for instance,the vortex in the near wake does not roll up and diffuse axisymmetrically.Field and Lagrange viewpoint were used to analyze flow field characteristic at fixed time and flow process during a time interval separately.Through the superposition of pressure contours and relative streamline, alleyway flow between votices was analyzed. The time-dependent fluid velocities were interpreted from the viewpoint of vortex structure.The standpoint that part of fluid was governed by distinct flow structures at different time gave insight to the phenomenon of substantial gaps between successive points in multiple folding steaklines.Several subzones were divided around the circular cylinder, the moving process and deformation of partial fluid were analyzed.
Coupled analysis on flow field-temperature distribution of aircraft-skin
Lü Jianwei, Jianwei Wang
2009, 35(8): 938-941.
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An analysis of the aircraft skin temperature field of the physical mechanism and the establishment of the aircraft skin temperature coupling calculation of the theoretical model were presented. A more complete factor of the various sources of heat on the surface skin of the aircraft was considered, including the aerodynamic heating, hot engine parts and various parts of the conduction, convection and radiation each other. Thus, the calculation model of three-dimensional flow field coupled with the solid wall was developed: skin used in solid-wall heat conduction model, and skin on atmospheric radiation used discrete ordinate method (DOM). Finally, the finite volume method and RNG k-ε turbulence model were employed to solve N-S equation. By numerical calculation method, the external and internal environment coupled heat transfer on aircraft skin was studied. The results show that the methodology is appropriate for numerical simulation of aircraft-skin temperature field.
Detecting method of quantitative colloidal gold test strip concentration
Wang Shuai, Zheng Dezhi, Fan Shangchun
2009, 35(8): 942-945.
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Colloidal gold immunochromatography assay concentration detecting method uses the colorimetric principle, which compares with the color standard card by using color varietal detection area, after a reaction between antigen of the measured liquid and antibody of the reagent strip. It-s a qualitative concentration analysis. At present, colloidal gold test strip is mostly semi-quantitative, which tends to limit its use. It adopted an embedded image processing system which based on the digital signal processor (DSP). The image information of the quantitative colloidal gold test strip was sampled by the image sensor complementary metal oxide semiconductor (CMOS), dealt by Bayer transformation, white balance processing, image feature information of fringe intensity extraction, and then established the functional relation between image feature information of fringe intensity and sample concentration, so it can realize accurate measurement. Compared with other methods, it has advantages of high precision, fast inspection speed and so on. The results show that the method of quantitative colloidal gold test strip concentration detection has upper applied value,which based on the DSP hardware platform, it precision can be up to ±5%,repeatability error reaches ±1%.
Contaminant concentrations dynamic prediction method for aircraft cabin based on estimating emission rates
Pang Liping, Qu Hongquan
2009, 35(8): 946-949.
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The probability of air pollution in aircraft cabin will be increased with the prolongation of passenger aircraft pilot time, so it is very important to predict the contaminant concentrations dynamically. The key is source emission rate estimation and concentration dynamic prediction method. For the source emission rate estimation, Minimum mean-square value can only get the static estimate values, while extended Kalman filter (EKF) can realize dynamic parameter estimation, but single EKF couldn't exhibit good ability both for the normal process and fault process. Therefore, a contaminant concentrations dynamic prediction method for aircraft cabin based on estimating emission rates was presented to solve this question. Double model filter was used to trace the steady state and transient state (sudden contaminant source happening) of system. The performance of parameter estimation and state prediction could be improved using this method, and then the accuracy and speed of air quality prediction could also be improved. Simulations were done to demonstrate the performance of algorithm.
Satellites formation reconfiguration with multiple impulses
Li Baojun, Shi Peng, Zhang Hao, Zhao Yushan
2009, 35(8): 950-952.
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Satellite formation flying (SFF) reconfiguration using multiple impulses was studied, which was mainly focusing on fuel efficiency.The elliptic reference orbit was considered. First the mathematical description of multiple-burn maneuver was established based on the analytical solution of the Lawden equation. Then object function was constructed as the total fuel which took the form as function of the imposing time and the magnitude of the previous n-2 burns, followed with the problem being solved utilizing the genetic algorithm. Finally the result was transferred into time domain to determine the magnitude, direction and imposing time of each of the impulse vectors. The simulation shows that the algorithm presented could lead to a more efficient method to implement the SFF reconfiguration.
Quiet zone evaluation method for offset single reflector CATR of separated transmitting-receiving feeds
Wang Hui, Bai Ming, Zhao Xin, Miao Jungang
2009, 35(8): 953-956.
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Based on the Lorentz reciprocity theorem, an evaluation method was proposed for the quiet zone of offset single reflector compact antenna test range (CATR) with separated transmitting-receiving feeds. Two feeds and reflector compose two separate and measured-mutually antenna systems, and there are two antenna apertures in the same quiet zone position. The electromagnetic characteristics of transmitting-receiving systems can be obtained respectively after the electromagnetic fields in the plane of two equal antenna systems were tested. The equal quiet zone fields can be obtained based on antenna acceptance theorem by transmitting-receiving antennas respective electromagnetic fields. The bistatic equal quiet zone is symmetrical and has narrower ranges, less ripple and less taper than those of monostatic. The equal quiet zone electromagnetic fields were calculated by physical optics. And this quiet zone evaluation method was verified with experiment test.
Robust vibration control of flexible piezoelectric structure
Yang Haifeng, Wang Xiaojun, Qiu Zhiping
2009, 35(8): 957-961.
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The robust vibration control for the flexible cantilever beam system with polytopic-type uncertainties and environmental disturbances is studied. Based on the state equation, the improved multi-objective H2/H∞ state-feedback robust control method is proposed for the flexible cantilever beam system by using a kind of extended linear matrix inequality (LMI). The presented method, which introduces multi Lyapunov functions for the polytopic-type uncertainties system, reduces the conservatism stemmed from the single Lyapunov function used in the unimproved method. The robust vibration control for the flexible cantilever beam system is simulated in Matlab by these two methods respectively. The results show that the flexible cantilever beam is well controlled via the two methods, and the improved method gets a better result.
Delaunay triangulation and Voronoi diagrams for Riemannian manifolds
Cheng Dan, Yang Qin, Cai Qiang, Jin Maozhong
2009, 35(8): 962-967.
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Delaunay triangulation and Voronoi diagrams in Riemannian space were studied. Firstly, the existence and generation algorithm of Delaunay triangulation and Voronoi diagrams were discussed. Then on the basis of analysing the existed research achievements, some properties of Delaunay triangulation and Voronoi diagrams for Riemannian were given and proved. The necessities of describing object by Riemannian manifolds and advantages of researching Riemannian manifolds by charts were presented. Finally, taking 2-manifold as an example, the algorithm of getting Riemannian manifolds according to initial data of models was described, which included creating charts, defining functions of manifolds, and so on. The algorithm of creating Delaunay triangulation and Voronoi diagrams of models based on charts was presented, and some examples were provided.
Effects of randomicity for strut cross-sectional areas on elastic properties of Voronoi open-cell foams
Lu Zixing, Wang Jianyue
2009, 35(8): 968-971.
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Based on Voronoi random foam model, the random distribution of strut cross-sectional areas(SCSAs) was introduced, and its effects on nonlinear compressive and tensile behavior and anisotropic elastic properties were investigated. Influences of the model irregularity and randomicity of SCSAs on foams were compared, and the effects of their interaction were also discussed. The simulation results indicate that, the dimensionless stress decrease as SCSAs get less uniform under compression and tension, and this effect becomes more apparent as strain becomes larger. However, as randomicity of SCSAs increases the poisson-s ratios become smaller under compression while become larger under tension.The relative anisotropic elastic moduli in the elongated direction and perpendicular direction decrease as random degree of SCSAs increases, however, the influence on Poisson-s ratio is insignificant. The effect of the interaction between the two random factors appears to be weak under tension, but strong on anisotropic elastic properties.
Analysis for environmental control system on civil aircraft
Liu Meng, Yuan Lingshuang, Wang Jun
2009, 35(8): 972-975.
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The advanced technology of environmental control system(ECS) from Boeing and Airbus was introduced. A new concept for ECS was raised, which applied vapor cycle refrigeration with frequency scroll compressor using refrigerant R134a. ECS penalty was calculated with the method of take-off gross weight. And the calculation and qualitative analysis were done for the new ECS energy consumption in the whole flight profile. Then the performance of the new ECS was compared with current ECS in fuel consumption. The results show that new system consumes less fuel(only 21.93kg/min, about 40% of traditional system), which could increase aircraft economic performance. And the health and comfort in cabin could be improved with the low noise, flexible regulation and clean air-supplying.
Fluid-structure interaction method on numerical simulation of elastic fairing separation
Zhang Xiaowei, Wang Yanrong, Xie Shengbai, Shan Peng
2009, 35(8): 976-979.
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A fluid-structure interaction (FSI) method for the simulation of the motion of elastic structure under the unsteady aerodynamic load induced by its motion was developed. For a given motion of the structure, the unsteady aerodynamic load of incompressible fluid was solved by immersed boundary (IB) method without the influence of elastic deformation for fluid being considered. The transient dynamic simulation of the thin-walled elastic structure was done. For a fairing separation in the ground test state, by comparing the deformation of fairing in different cases: rigid, flexible structure with or without surface loading, the feasibility of the FSI method is verified.
Research and application of analysis leads design method
Song Yuwang, Xi Ping
2009, 35(8): 980-985.
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The analysis leads design(ALD) method was advanced to summarize the key concepts and analyze the essential ideas from the iterative phenomena during the product design process. The concepts of design information(DI), design activity(DA), design model(DM), design file(DF) and analysis leads design flow(ALDF) in the ALD method were defined. As self-driven design flow, ALDF was the core concept of the ALD method. The process of establishing the ALDF was the ALD method. The design information and the design activity of the ALD flow were elaborated. The serial and parallel methods to order the design activity of the ALDF were emphasized, of which the function of time cost was given. The product design plan was optimized by the ALDF to improve the design quality and efficiency. Some key techniques of the ALD method were resolved, and the ALD method was exemplified by the structure design of the turbo-jet blade. And the conditions, the self-driven design flow, the diagram of geometry variables and performance variables of the example were given.
Design of cabin layout for blended wing body passenger transports
Liao Huijun, Zhang Shuguang
2009, 35(8): 986-989.
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The blended wing body (BWB) commercial aircraft configuration has become a hot topic and has been widely studied around the world. As a new configuration, its cabin design is very different from the conventional, so it-s necessary to study the new problems with the BWB cabin design. Focused on the marked traits, some basic cabin-relative issues were studied. The cabin layout must meet the CCAR-25 criteria, as well as the passengers- comfort need, so the cabin related airworthiness and comfort items were firstly abstracted. A cabin layout solution and the accompanying parameterization method were followed. The 250 seating BWB transport was then taken as example for the details of layout design. The results show that the parameterization method of the cabin layout is feasible for the need of a BWB family. However, such requirements as emergent evacuation within 90 seconds must be further highlighted and verified by experiments.
Adaptive forwarding cluster routing protocol for mobile ad hoc network
Wang Li, Liu Kai, Liu Ting
2009, 35(8): 990-995.
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A novel routing protocol, namely adaptive forwarding cluster routing (AFCR) protocol, was proposed to improve the network scalability of a large scale mobile ad hoc network (MANET). In the AFCR protocol, nodes were divided into several 1-hop clusters by mobile clustering algorithm based on the lowest ID. With the help of clustering timer, it could quickly form cluster architecture after two rounds of control message exchange, and could form clusters simultaneously at different points in the network. Local routing information was exchanged between neighboring nodes to establish routes between cluster-heads in adjacent clusters, which were further used to propagate routing information to nonadjacent clusters to set up routes between them. Based on cluster architecture and local routing information, the proposed protocol can adaptively forward data packets between nodes. Simulation results show that compared with the destination-sequenced distance-vector (DSDV) and rapid route reconstruction DSDV (RRR-DSDV) protocols, the proposed protocol can improve network performance in the present of a large number of mobile nodes and heavy traffic load.
Ground moving target detection method of parallel mode airborne bistatic SAR
Shi Hongyin, Zhou Yinqing, Chen Jie
2009, 35(8): 996-1000.
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A method of slow-moving ground target detection and parameter estimation with parallel mode airborne bistatic three-channel synthetic aperture radar (SAR) was presented. According to the characteristic of bistatic SAR, fractional Fourier transform (FrFT) technique was adopt to focus the moving target and improve the signal to clutter ratio, clutter suppression interferometer techniques was adopt then to suppress clutter and estimate the parameters of moving target accurately. From the spatial geometry model and echo signal model of the system, the flying condition of transmitting and receiving plane must satisfy when clutter be eliminate and the method of moving target parameters estimation were derived. Finally, computer simulation results validate its effectiveness.
Color matching of aircraft interface design
Zhang Lei, Zhuang Damin
2009, 35(8): 1001-1004.
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Aiming at the problems of aircraft display interface design, a simulation model of flight information display interface was developed for ergonomic experiment. Lots of experiments were taken based on this model. The integrated use of subjective and objective measurement method for different match color characteristic was studied. Reaction time was used as performance evaluation indictors and fuzzy math was used for subjective data processing. The following are the findings of the experiments: The order of space identification and the degree of preference under different color match were identified; the task performance under different color match and the degree of preference is incomplete. These colors, such as white/red, brown/yellow, dark gray/blue, black/light green, white/blue, would be appropriate for background/target color combination, and white/yellow, black/blue are not.
Fault diagnosis for civil aviation aircraft based on rough-neural network
Liu Yongjian, Zhu Jianying, Xia Hongshan
2009, 35(8): 1005-1008.
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To solve the defects of traditional fault diagnosis neural network, such as long training time, complex structure and single-valued input, a fault diagnosis system for civil aircraft based on rough-neural network was proposed. Rough set theory was applied to the front-end neural network to reduce the data of civil aircraft fault sample so as to remove the disturbance of redundant attributes, and overcome the impaction of unrelated data that imposed on the performance of network learning, simplify network structure. Secondly, by using the rough neurons instead of the traditional neurons, the performance of network was improved, and the scope of the application of network was expanded. The effectiveness of this method was verified by Airbus A320 aircraft fault diagnosis test .
Stability analyses of demand information sharing supply chain systems
Wang Jing, Tang Ling, Wang Xun
2009, 35(8): 1009-1012.
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The stability of production/inventory control system is an important indicator in supply chain management, and demand information sharing (DIS) mechanism has been widely adapted in managerial section. However, research on DIS stability boundaries and conditions is by far very limited. Based on control engineering, a DIS two-echelon supply chain dynamic model was established. The stability boundary of the system parameters was derived analytically, and then verified by simulations. The results show that system stability can be improved by appropriate parameter settings. For stepwise customer demand input, the effects of system parameters to system dynamic responses including order rate, inventory level and work-in-process were analyzed. Valuable insights into dynamic behavior of supply chain systems are obtained, and then managerial strategies are proposed.
Ultrafast-convert hybrid pulse square-wave variable polarity TIG arc behavior
Cong Baoqiang, Qi Bojin, Zhou Xingguo
2009, 35(8): 1013-1017.
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Based on a novel ultrafast convert hybrid pulse variable polarity main circuit topology, the ultrasonic pulse current which had a frequency of more than 20kHz was superposed in the positive current duration to achieve the hybrid pulse variable polarity current which crossed zero with no dead time and with fast rising and falling edge. The effect of pulse current parameters on the arc characteristics and the behavior of aluminum alloy weld noted by the weld depth and width were studied. The experiment results show that the ultrasonic pulse current has a significant influence on the pinch effect of hybrid pulse variable polarity TIG arc, resulting in the obvious reduction of arc radial dimension. Increasing the pulse current frequency and amplitude as well as decreasing the pulse current duty cycle in special ranges, the weld melt rate is enhanced which may be beneficial to improve the weld quality of aluminum alloy obviously using hybrid pulse variable polarity TIG arc welding technique.
Comparison between quasi-static indentation testing and drop-weight impact testing on delamination onset damage
Guo Yuan, Guan Zhidong, Liu Debo, Meng Qingchun
2009, 35(8): 1018-1021.
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To discuss the delamination onset load, quasi-static indentation tests and drop-weight impact tests were performed. The effects of the material and plying pattern on the delamination onset load were also studied. Moreover, the delamination threshold energy levels were found and the corresponding damage was analyzed. The results show that the delamination onset load increases along with the impact energy, and the delamination onset load in the quasi-static indentation is lower than in the low-velocity impact. Massive delamination happens in laminate panels when the energy reaches the delamination threshold energy, and the rigidity descends rapidly.
Method for estimating operating distance of IR imaging system under complex backgrounds
Diao Weihe, Mao Xia, Liang Xiaogeng
2009, 35(8): 1022-1026.
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For the application limitation of traditional operating distance model under complex backgrounds, the traditional equation was improved by adding the idea of probability distribution. In the new equation, the variables operating distance and background IR radiance were replaced by vectors, whose dimensions could be calculated according to gray distribution of background image. Then, a new model which is valid in various backgrounds was established. In order to calculate the infrared signature of complex background, a new method that gets radiance from image gray value by establishing radiance-gray function was proposed here. The operating distance calculation instance shows that the new model can accurately estimate the operating distance under complex backgrounds.
Retrieval algorithm for optical parameters of aerosol using polarized remote sensing
Sun Xia, Zhao Huijie
2009, 35(8): 1027-1030.
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The upwelling radiances at the top of the atmosphere consist of both atmospheric scattering and ground surface reflection. In general, the latter is larger than the former over the land. This makes the extraction of aerosols over land very difficult. It is known that polarization features strongly depend on characteristics of scattering particles. So it is efficient that to retrieve the aerosol characteristics over land area by using this polarization information. Based on the theory of vector radiative transfer algorithms, the relationship of the aerosol-s properties with parameters in the vector radiative transfer mode was analyzed and the algorithm of look-up table method was confirmed. Using the multi-angle data of polarization and radiance of the polarization and directionality of the earth-s reflectances(POLDER), an algorithm that estimates the aerosol optical properties and surface albedo was developed based on radiance and polarization look-up table with an iterative method. The aerosol optical thickness, efficient radius, refractive index and surface albedo over the Beijing, Xianghe and Dalanzadgad stations were retrieved. The obtained results were validated with the aerosol robotic network (AERONET) measurements.
Homogeneity testing of aluminum metal matrix composites by TIRP method
Gao Yifei, Zhou Zhenggan, He Fangcheng
2009, 35(8): 1031-1034.
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In order to evaluate the homogeneity of SiCp reinforced aluminum metal-matrix composites (MMC) fabricated by powder metallurgy, an ultrasonic velocity imaging was carried out with the method of thickness independent reflector plate (TIRP). Accuracy and precision were improved and the thickness was unnecessary in the velocity imaging with TIRP method. Firstly, the purpose of ultrasonic velocity imaging of MMC and basic principle of TIRP were introduced. Secondly, the structure of ultrasonic scan system was described. A double-scan method was applied to improve accuracy. Thirdly, the experiment results of ultrasonic velocity imaging of MMC specimen obtained with back surface echo (BSE), single-scan and double-scan method of TIRP respectively were compared and discussed. The images generated with double-scan method of TIRP have more details than those with BSE and single-scan method. Finally, the factors affecting accuracy and precision in the implementation were considered which may be used to advance the experiment.

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