2008 Vol. 34, No. 7

Display Method:
Bi-objective optimization design of civil transport wing using N-S equations
Wang Xiaolu, Zhu Ziqiang, Wu Zongcheng, Chen Zemin
2008, 34(7): 739-742.
Abstract:
A bi-objective(BO) optimization method was proposed for civil transport wing design.The thickness and twist angle of wing sections along wingspan were chosen as the optimal design factors, the two goals were the lift-to-drag ratio and wing's volume at fixed lift coefficient. Navier-Stokes(N-S) equat...
e-Government data exchange overlay network
Liu Xudong, Ma Xiaoxuan, Xiong Zhang, Han Jun
2008, 34(7): 743-746.
Abstract:
Data exchange is the kernel of e-Government. The establishment of an e-Government data exchange overlay network on application layer is one of the crucial parts of the solution to this issue. Based on the analysis of the characteristics of e-Government data exchange, an overlay network conceptual mo...
Reproject and correct optimization in determining C-arm extrinsic parameters based on geometry constraints
Wang Tianmiao, Luan Sheng, Hu Lei
2008, 34(7): 747-750.
Abstract:
The precision of C-arm extrinsic parameters is critical to computer assisted surgery systems to implement the registration of X-ray image and surgery physical space intraoperatively. Feature point extraction errors may cause deviation of extrinsic parameters using current calibration methods. A proj...
Effect of combined impingement cooling and film cooling on hybrid cooling effectiveness
Wang Kai, Xu Guoqiang, Sun Jining, Tao Zhi
2008, 34(7): 751-754.
Abstract:
The present study concentrates on the computational investigation of a new cooling configuration of a double-layer cavity in the middle section of modern turbine blade. A three-dimensional Navier-Stokes code with standard k-ε turbulence model as well as with wall functions was used to compute the fl...
Hybrid RANS/LES model based on turbulent scale
Li Bin, Wu Songping
2008, 34(7): 755-758.
Abstract:
The main difference between the inner model of BL(Baldwin-Lomax) turbulent model and the Smagorinsky subgrid model lays in the different methods to calculate the turbulent scale. The governing equations of RANS(Reynolds average numerical simulation) and LES(large eddy simulation) are of same form. A...
Software-hardware cooperate priority scheduling strategy for autonomous test
Zheng Wei, Meng Xiaofeng, Zhang Weijun
2008, 34(7): 759-762.
Abstract:
Autonomous test is one of the key technologies for building spacecraft autonomy. For the problem of task priority scheduling in real time operation system, a mix scheduling strategy with software-hardware cooperate was presented. After analyzing the influence factors of task importance in the comple...
Evaluating failure risk for product design scheme based on knowledge model
Wang Bin, Tang Xiaoqing
2008, 34(7): 763-768.
Abstract:
Considered the relationship among failure modes, a failure risk evaluation and optimization method for mechanical product design scheme based on knowledge model was proposed. The main relationship among failure modes was identified by data clustering. The method of computing the relationship coeffic...
Random modulation for fiber optic gyroscope based on four-states Markov chain
Jin Jing, Li Min, Song Ningfang, Zang Chunxi
2008, 34(7): 769-772.
Abstract:
Electrical crosstalk from modulation signal deteriorates bias stability, dead band and linearity in digital closed-loop fiber optic gyroscope (FOG). A random modulation based on a four-states Markov chain was presented to attenuate the electrical crosstalk. With periodicity of sine function and equi...
RAIM algorithm for identifying simultaneous two-faulty satellites
Zhang Qiang, Zhang Xiaolin, Chang Xiaoming
2008, 34(7): 773-777.
Abstract:
A new receiver autonomous integrity monitoring(RAIM) algorithm was proposed for identifying simultaneous two-faulty satellites. The optimal parity vector method was studied, and the results showed that the fault of one satellite may counteract the fault of the other satellite, which reduced correct ...
Modal parameters identification for flight vehicle based on the continuous wavelet transforms
Wu Xiaodong, Deng Zhongmin
2008, 34(7): 778-781.
Abstract:
A multi-input multi-output (MIMO) method for identifying flight vehicle structure modal parameters was proposed based on the continuous wavelet transforms. The auto regression(AR)model in the wavelet domain was established by applying the continuous wavelet transform to discrete equations of motion....
Optimization design of vision display interface in plane cockpit based on mental workload
Kang Weiyong, Yuan Xiugan, Liu Zhongqi
2008, 34(7): 782-785.
Abstract:
To confirm the optimization design for vision display interface of a plane cockpit in the design phase, the comprehensive evaluation of mental workload has been used. Colligating the three mental workload evaluation methods, which are main task evaluation method, physiology measure method and subjec...
Simulation analysis of pump and valve combined EHA efficiency design
Ji Youzhe, Qi Xiaoye, Qiu Lihua, Wang Zhanlin
2008, 34(7): 786-789.
Abstract:
The efficiency influencing factors of the valve control section of valve and pump combined electrical hydraulic actuator (EHA) were analyzed. The method to improve the system efficiency by decreasing the design value of source pressure was proposed. According to the working characteristics of the pu...
Evaluation of engine thrust loss for canard-spanwise blowing
Wen Ruiying, Liu Peiqing
2008, 34(7): 790-793.
Abstract:
The results of force measurement in low speed wind-tunnel show that canard-spanwise blowing can increase the lift of high angle of attack, delay the breakdown of wing vortex and enlarge the stalling angle of aircraft. But canard-spanwise blowing must bleed air from engine, which makes the engine thr...
Design of multi-slice CT data acquisition system and its measurement
Ma Xin, Guo Hong
2008, 34(7): 794-797.
Abstract:
A multi-channel, high density and precision real-time DAS(data acquisition system) design approach was presented. It based on the embedded soft core structure, and the real-time signal processing pipeline of multi-channel data buffer, format conversion, coding transmission and ping-pang operation we...
Fault prognostic algorithm based on dual estimation and particle filter
Zhang Lei, Li Xingshan, Yu Jinsong, Gao Zhanbao
2008, 34(7): 798-802.
Abstract:
Supposing that system fault evolution process is expressed by a state space model with unknown slow time-variant parameters, then the fault prognostics can be formulated as a problem of estimating model states for some future time while knowing all the information about system till time step now. An...
Motor speed robust control with multiplying nonlinear property
Bai Guochang, Qi Xiaoye, Wang Zhanlin
2008, 34(7): 803-806.
Abstract:
The control method that combined variable speed and variable displacement is a new type of cubage control. It has the advantages of high efficiency and relative fast response. But its multiplicative essential nonlinear property causes trouble to control. To the pump controlled motor speed system wit...
Digital definition of aircraft composite structures for manufacture
Zhang Lihua, Fan Yuqing
2008, 34(7): 807-811.
Abstract:
In order to satisfy the data demands and requests for composite structure-s producibility of manufacture process in the composite structures- digital development environment, the whole contents of digital definition of aircraft composite structures for manufacture were summarized. The direction datu...
Early-warning of engineering-project risk model research based on maximum entropy clustering
Tang Baojun, Liu Xiaolong, Qiu Wanhua
2008, 34(7): 812-815.
Abstract:
Due to most of current early-warning of engineering risk only give a alarm,but cannot forecast, engineering-project risk early-warning based on entropy optimal model was proposed. Firstly, minimum J-divergence entropy was applied to extract the risk early-warning index and to find out the most effec...
Dressing performance and dressing mechanism of diamond roller
Zhang Hongxia, Chen Zhitong, Chen Wuyi
2008, 34(7): 816-820.
Abstract:
Dressing of grinding wheel has especially significant effect on grinding behavior when grinding titanium alloys because of serious adherence between abrasives and workpiece material. Experiments of rotary diamond dressing of SG wheels for titanium alloys grinding were conducted to investigate the ef...
Numerical simulation of aircraft integrated thermal management system in steady working condition
Chang Shinan, Yuan Meiming, Yuan Xiugan
2008, 34(7): 821-824.
Abstract:
Steady simulation model of aircraft integrated thermal management system was established and simulation blocks were constructed on the platform of MATLAB software. Simulation was conducted for the system for different Mach numbers and different altitudes. The outlet temperature and flow flux of key ...
Camera self-calibration technique for vision system in front for teleoperation system based on pointing rotation
Wang zhifeng, Wang Zhanlin, Fu Yongling
2008, 34(7): 825-829.
Abstract:
Camera self-calibration technique for vision system in front for teleoperation system based on pointing rotation is an effective method. The problem that the calibration object can not be put in front of the camera, when the teleoperation is going on and the camera parameters need to be modified can...
Estimation model of comprehensive index of heat stress on fighter pilots on ground
Qiu Yifen, Fu Yang, Li Yanjie
2008, 34(7): 830-832.
Abstract:
Comprehensive index of heat stress(CIHS) was given to pay attention to the high temperature influence on fighter pilots, and to supply proof to take necessary protection to the pilots. According to the airport weather report thermal environment parameters of fighter cabin were estimated first, heat ...
Application of time-frequency analysis to ultrasonic-guided-wave signal interpretation
Zhou Zhenggan, Feng Zhanying, Gao Yifei, Zhu Xuan
2008, 34(7): 833-837.
Abstract:
Ultrasonic guided wave is a kind of non-stationary signal and characterized by disperse. Its frequency spectrum variation can not be traced with traditional methods in time domain and frequency domain respectively. To solve the problem, the non-stationary characteristics of guided waves were studied...
Fast RCS calculation technique for targets coated with multi-layer RAM
Wang Yong, Xu Xiaojian
2008, 34(7): 838-843.
Abstract:
A fast radar cross section (RCS) calculation technique for targets coated with multi-layer radar absorbing materials (RAM)was presented. The targets were modeled as a combination of facets and wedges. Physical optics (PO) method and impedance boundary condition (IBC) were used for RCS calculation of...
Low voltage NMOS bulk-biased folded-cascode Gilbert mixer
Song Dan, Zhang Xiaolin, Xia Wenbo
2008, 34(7): 844-848.
Abstract:
By using the bulk-biased technology and folded-cascode approach, the problem of stacking input-and switching-transistors within 0.8V supply voltage was solved. A low voltage N channel metal-oxide-semiconductor (NMOS)bulk-biased folded-cascode Gilbert mixer (BBFCM) was implemented in a SMIC 0.18μm ...
Estimation method for inadequate fatigue test result of structures with multi-similar-details
Bao Rui, Zhang Jianyu, Fei Binjun
2008, 34(7): 849-852.
Abstract:
A method for estimating fatigue life distribution parameters with inadequate result obtained by fatigue test of structures with multi-similar-details was proposed. Based on the assumption that fatigue life follows the log-normal distribution and 2-parameter Weibull distribution respectively, the rel...
Analysis of piezoelectric ceramics PLZT based on ANSYS
Liang Lei, Wang Shaoping, Cao Feng
2008, 34(7): 853-856.
Abstract:
In order to avoid the defect in traditional analytic method and the finite element analysis (FEA)used in the analysis of piezoelectric ceramics, FEA software ANSYS was introduced to analyze the characteristics of lanthanum-modified lead zirconate titanate (PLZT) ceramics. The software ANSYS and its ...
Topological structure optimization of medical hybrid robot based on dexterity
Yun Chao, Tang Can
2008, 34(7): 857-860.
Abstract:
The current methods for dexterity analysis of medical robot were summarized. With numerical approach based on service sphere, dexterity calculation for 5R serial robot and for 4H parallel robot was implemented, and each task dexterity was obtained. Because of kinematics-complexity of hybrid redunda...
Identification of coaxial helicopter dynamic system with elman neural networks
Xi Haijiao, Zhang Xiaolin
2008, 34(7): 861-864.
Abstract:
A modified elman neural network according to the dynamic & kinematic equations of helicopters was established, the training algorithms for the neural networks(NN) was derived, and the training steps and their realizations were provided. From the telemetry data collection of real trial flights of...