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2011 Vol. 37, No. 4

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Guidance method of low altitude penetration missile based on optical sensor
Sun Jian, Liu Xing, Wu Sentang
2011, 37(4): 379-383.
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To increase penetration rate for low attitude cruise missile, a minimum deviation of the missile along the flight path must be satisfied, after the flight path plan to be finished. During the missile flight simulation, missile overload exceeds requirement when waypoint is switching and overshoot time becomes extended. To solve this problem, new missile guidance method for longitudinal and lateral aisles and command generated method were proposed, control law of missile was designed to satisfy requirement of the missile low attitude penetration. By way of terrain following and terrain avoidance (TF/TA) 6-degree of freedom simulation, performances of two guidance methods on TF/TA were compared. Simulation results shows that, use this new guidance method of longitudinal and lateral aisles and command generated method, TF/TA performance of missile is increased.
Modeling of hydrogen engine parameters design during flight to orbit of reusable launch vehicle
Jin Ping, Wang Xiaowei, Li Mao, Cai Guobiao
2011, 37(4): 384-389.
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In order to investigate the influence of hydrogen engine parameters on launch vehicle performance, the mathematical models suited for single stage to orbit reusable launch vehicle flight process were brought up based on hydrogen engine performance parameters, including rocket motion equations, flight control conditions and vehicle mass model. The vehicle mass variety rules were discussed in detail changed with hydrogen engine mixture ratio during flight to orbit. The results show that on the condition the vehicle gross mass set, when hydrogen engine mixture ratio increases from 4 to 14, propellants mass and engine mass decrease firstly and then increase, tank mass decrease all the time, which synthetically bring forth payload mass increase firstly and then decrease.
Web service selection approach based on the authenticity of QoS data and workflow model
Yuan Yuqian, Hu Xiaohui
2011, 37(4): 390-394.
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The existing QoS(quality of service)-based services selection approaches always assume that the QoS data coming from service providers and users are effective and trustworthy, which is actually impossible in reality. A service selection approach based on the authenticity of QoS data and workflow model was proposed to solve the problem. For the QoS data coming from service providers, the statistics of past runtime data to revise the providers- QoS data were used. For the subjective evaluation coming from users,the confidence values of users were calculated based on the workflow-organization-model,and then the evaluation was computed by using the confidence.At last,the optimal web services could be selected by combing the two values as the judgment standard. The experimental results show that this approach can effectively weaken the influence of untrustworthy QoS data on Web service selection and strengthen the accuracy of service selection.
Aerodynamic and dynamic characteristics of aeronautic towed decoy
Lu Yanlong, Tong Zhongxiang, Wang Chaozhe, Jiang Yun
2011, 37(4): 395-398.
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The relative space position between aviation towed decoy and plane which is protected and release method of aviation towed decoy are the main factors that influence the result when missile is jammed by decoy. A new finite segment method was developed to make up the deficiencies of conventional finite segment method. Aerodynamic movement characteristics of aeronautic towed decoy were transformed to the question how to model and compute angles between tow and towing aircraft track coordinates. The geometry relationship between velocity vector of towing aircraft and tow was analyzed, so dynamic fallow models of tow and towing aircraft were established. The dynamic characteristics of towed decoy were calculated when towed aircraft does different flights. The result indicates that the arithmetic is simple, valid and better to simulate decoy-s dynamic characteristics.
Design and analysis of single-axis-double-pin hinged door for large-scale container
Wang Wenlong, Ling Guilong, Cai Guobiao
2011, 37(4): 399-404.
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The hinged door of the large-scale, horizontal container is usually deformed and distorted during the process of assembly and long-term usage, which can prevent the door from closing tightly and thus affect the sealing performance. A novel single-axis-double-pin hinged door was developed for a 5.5-meter-diameter, large-scale chamber, which was under construction for the plume experiment in vacuum. The design and analysis was conducted for the rotating mechanism, the restrictive switch device, as well as the elastic support unit at the bottom of the flange. The finite element method (FEM) was finally adopted to check the structural requirements. The results shows that the  y-direction displacement, caused by the gravity, is the main factor of the combined displacement of the door. At the junction of the hinge and the flange, the range of the concentrated stress will shrinks, and the value of stress will decline, if a elastic support force is exerted at the bottom of the flange, which also ensures the combined displacement of the door less than 10mm. The strength and stiffness requirements are satisfied for the single-axis-double-pin hinged door. This work will provide insight for the future design of the similar scale hinged door.
Deflection prediction for inflatable wing based on artificial neural network
Wang Zhifei, Wang Hua, Jia Qinping, Han Jing
2011, 37(4): 405-408.
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To accurately predict the deflection of loaded inflatable wing, a basic impact of influence deflection was analyzed, method of orthogonal experiment was used to ascertain the main impact of influence deflection. The main impact of influence deflection was used as intputs and deflection was used as outputs. A BP artificial network model was established by using plenty of experimental statistics as training specimens, trying to access all kinds of crytic layers and elements, choosing trainlm as optimal function.Ten predictions were done continuously aiming at every group after twelve groups of specimens were selected from experimental results. The relative error between the predicted result and the experiment result is 4.48%, and standard deviation 1.033 7. The analysis results show that the rellative error between the predicted result and the messured reslut are slight for conrete specimens, which indicates that the established artificial network model has high prediction precison.
Monitoring system for vehicle overloading base on paste-type strain sensor
Chen Guanghua, Ju Na, Yang Fei, Li Jianwei
2011, 37(4): 409-414.
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The on-board weighing technology was studied for the overloading of vehicle. A monitoring system was designed for overloading based on the on-board weighing device and short message technology. The system used paste-type strain sensor that installed in vehicle-s leaf spring to obtain load on the leaf spring and then calculated and displayed the total load of vehicle. When vehicle is overloaded the monitoring device control on-board short message terminals to send a short message of overloading,also it provided data to the relevant departments. The system can accurately detect the vehicle load after repeated verification, which can be used for the departments of transportation and highways to charge, manage and punish the loading vehicle.
Motion analysis and simulation of tetrahedral rolling robot
Zhang Lige, Bi Shusheng, Peng Zhaoqin
2011, 37(4): 415-420.
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The research status of tetrahedral robot was analyzed. The mechanism of tetrahedral rolling robot was introduced. The robot comprises of six extension struts and four node flats. When the center of gravity(COG) of tetrahedron exceeds the stability region, the robot will roll. Kinematic model in different motion phase was analyzed according to the structure and motion characteristic of the tetrahedral robot, and the rolling critical condition was formulated. The simulation model was built by virtual flat software Adams, and the effectiveness of the method was testified through simulation and experiment. The results provide important reference for the dynamic analysis, optimization design and control of the tetrahedral rolling robot.
Bionic design on the fluid mechanics experimental model of butterfly hovering fly
Wei Lai, Shen Gongxin, Huang Shuoqiao, Guo Peng
2011, 37(4): 421-427.
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As its unique morphological features (broad wings with small aspect ratio, complex wing shape), and the distinctive kinematics (low flapping frequency, the stroke plane is nearly perpendicular to the body; no wing rotating, but obviously body pitching and oscillating as wing flapping), butterfly fly is a special research subject in exploring insect high lift mechanisms. In order to take in-depth insight into the bio-fluid mechanics and the high lift mechanisms of butterfly hovering fly, it is necessary to design and manufacture an electromechanical model of flapping butterfly to simulate the flapping modes of the butterfly.A new designed electromechanical model of flapping butterfly which had the wings and the body just like the real butterfly was introduced. The electromechanical model can fix positions and simulate different flapping modes of the butterfly, including the wings- flapping and body-s rotation and up-down-oscillating movement. So it is useable for the experiments of flow visualization and particle image velocimetry(PIV).
Safety simulation technology based on finite state machine
Wang Bei, Zhao Tingdi, Jiao Jian
2011, 37(4): 428-432.
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The safety modeling and simulation method based on finite state machine theory was proposed to research the dynamic change mechanism of the accident in system, as well as explore the movement during the accident evolution and establish exact emergency treatment. The modeling and simulation platform for accident mechanism and control process was developed in the environment of Simulink/Stateflow. The combination of system mechanism model, safety state control model and emergency treatment model can be achieved in this platform. Therefore the dynamic simulation for such systems that integrated with human-machine and environment can be implemented in an effective way. Then the simulation results can be obtained, which provide reference for the precise identification of the accident process and the establishment of exact control treatment. Finally the accident simulation example was given, which proved the validity and rationality of this proposed method.
Multiple fault diagnosis method with unreliable test
Fang Jiayong, Xiao Mingqing, Wang Xueqi, Yu Hang
2011, 37(4): 433-438.
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Aiming at low diagnosis precision and high false alarm of complex systems diagnosis, a multiple fault diagnosis method was proposed. In order to solve the difficulties of building Bayesian networks’ structure and conditional probabilities table, the system-s multi-signal flow graphs model was built. By introducing unreliability probability into conditional probabilities table, the proposed method-s robustness was enhanced. The problem was concluded as the extreme value problem with inequality constraints by using Bayes maximal posterior probability. The optimized result was obtained by the 0-1 programming implicit enumeration. The electronic equipment of guidance system was explored to illustrate the effectiveness of the proposed method.
Design method for specification of force-limited vibration testing
Mo Changyu, Yuan Hongjie
2011, 37(4): 439-445.
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The method based on the complex two degrees of freedom system(TDFS) mode to design the specification of force-limited vibration testing was proposed. In the method, dynamic sub-structure was adopted to calculate modal effective mass and modal residual mass of specimen structure and supporting structure.The complex TDFS model parameter of vibration system in different frequency bands was defined according to the distribution of mode effective mass in frequency domain.The force spectrum and acceleration spectrum of contact surface between specimen and supporting structure was defined with the excitation condition of supporting structure. Spectrum envelope is the force-limited vibration test profile. Simulation results demonstrate that the force-limited vibration test conditions defined by this method is much more reality on vibration environment than conventional acceleration test condition.
Forward and inverse solution of a 9-DOF hybrid robot for minimally invasive surgery
Zhang Fan, Liu Da, Wang Tianmiao
2011, 37(4): 446-451.
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Focusing on the recently developed "5R+4T" 9-DOF(degree-of-freedom) hybrid robot for thoracoabdominal percutaneous cryosurgery by the robotics institute of Beijing University of Aeronautics and Astronautics, an original single-constraint-condition algorithm was put forward to obtain analytic solutions to the forward and inverse kinematics of the robot, based on the product of exponentials (POE) formula using inverse transformation method and characteristics of inverse matrix. The mutual derivation between the forward and the inverse solution, namely, the effectiveness of the algorithm, was demonstrated by several sets of numeric data. A modification for the algorithm was also advanced by discussing the demonstration results, so as to expand the range of its applicability. This algorithm overcomes the difficulties in performing the forward and inverse kinematic calculations which result from the DOF redundancy and the structure complexity of the hybrid robot, bringing a new idea about solving kinematic problems of multi-DOF hybrid robots.
Global K-exponential stabilization of nonholonomic chained systems by continuous feedback
Li Mingjun, Ma Baoli
2011, 37(4): 452-457.
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Two global continuous feedback control laws were proposed to stabilize nonholonomic chained systems, namely, the continuous time-varying feedback control law and the dynamic time-invariant feedback control law. The first control law achieved continuity and asymptoticality by using an exponential decay term related to the initial state values, while the second achieved controllability, continuity and asymptoticality by setting the initial value of the introduced assistant state variable. The two control laws could guarantee that all the states converged to zero continuously and asymptotically at exponential rates, which overcame the short-comings that the previous control laws could not achieve continuity, asymptoticality and exponential rates at the same time. The proposed control laws are applied to the mobile robot and a four-dimension chained system. The simulation results show that the smoothness and convergence rates of the state/control trajectories are better than the previous works.
Method for measuring projection position of focal point based on space geometrical relations
Li Bin, Fu Jian, Zhou Zhenggan
2011, 37(4): 458-461.
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In order to reduce artifacts on industrial computed tomography(CT) images, one method for measuring the projection position of the focal point based on space geometrical relations was put forward. Computer simulations and experiments were carried out. The method established analytic equations between the projection position of the focal point and the projection position of the center of rotation. The projection position of the focal point was calculated through several times calculation of the center of rotation in different places. The method required the turntable to have three freedoms: rotating, moving parallel to the detector and moving vertical to the detector. Computer simulations and experiments results demonstrate that this method is effective to reduce CT artifacts. Compared with the current methods, the proposed algorithm need not any special phantoms and need not any priori geometry parameters. It is more convenient for engineering.
Investigation on inertial platform multi-position rolling self-calibration
Bao Weimin, Shen Gongxun, Li Huabin
2011, 37(4): 462-465.
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The guidance instrument errors are the main factors of reducing the hitting accuracy of inertial-guided missile. The measuring error of inertial platform is the major part. So the multi-position rolling self-calibration approach for inertial platform was studied. The gyroscope error models and the accelerometer error models were firstly built, and multi-position rolling self-calibration test was designed. Based on the scheme, numerical multi-position rolling self-calibration simulations were conducted, and influence factors were anglicized. Simulation results show that this approach can effectively separate the error coefficients. Under normal locked errors, the error coefficients separation precision is better than 99%, accordingly, the hitting accuracy of missile is increased.
Method base on multi-channel satellite cloud image for typhoon segmentation
Qian Huaming, Jiang Bo
2011, 37(4): 466-471.
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A modified level set method for typhoon segmentation base on vector image was proposed to improve the accuracy of typhoon prediction. The C-V model was extended to the vector space and an energy term without re-initialization was introduced. An iteration convergence condition was proposed,and the parameters of the model and the method of segmentation were designed for the features of cloud image. Through the use of cloud image information and avoiding the unnecessary iterative calculation, this method can accelerate the speed of curve evolution and improve the accuracy of segmentation. The experimental results verify the validity and feasibility of the proposed method. The expected typhoon segmentation effect is achieved with the average false target rate of 1.21% and the average false non-target rate of 2.25%.
Improved method of satellite positioning and dilution of precision
Chen Canhui, Zhang Xiaolin
2011, 37(4): 472-477.
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In satellite navigation system, the traditional algorithm of solving dilution of precision (DOP) and satellite positioning based on least square method is the direct matrix inverse (DMI) method. In order to overcome the disadvantages of high computational burden and poor numerical stability of traditional DMI method, an improved method of satellite positioning and DOP was presented based on the matrix U T DU decomposition, which made use of the symmetric and positive definite performance of the measurement matrix. The correctness and validity of the new method can be guaranteed by the strict mathematical theory. The numerical results show that, in comparison with the traditional DMI method, the reduction of operational volume of positioning is about 60% and that of solving DOP is about 36% by the proposed method. At the same time, the condition number of the solving matrix of the improved method has reduced considerably after decomposition and the numerical stability is significantly improved.
Multidisciplinary design collaborative optimization for common aero vehicle
Zhang Zhiqiang, He Linshu
2011, 37(4): 478-482.
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Collaborative optimization (CO) method applied into overall design optimization for common aero vehicle and coupled relationship between disciplines were investigated. Process and characters of CO were analyzed. Aimed at common aero vehicle optimization design, research how using CO to built optimization model. Research result shows CO compared with multi-discipline feasible(MDF) has more converge speed, and the reason is system level optimization of CO method is constrained by three subsystem level optimization, constringency of design space speed up, thus realize rapidly iterate converge.
Effect of micro-jets mixing enhancement on infrared radiation of plume
Zhu Xijuan, Eriqitai Li, Jiajun Wangqiang
2011, 37(4): 483-486.
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The infrared radiation in 3~5μm band of the unforced plume and the forced plume which is mixed by injecting micro-jets into subsonic shear layer were calculated by a three-dimensional infrared(IR) radiation code of the plume, it was developed by the finite volume method (FVM) in non-gray absorbing-emitting media. The 3-D flow field of the jet was simulated numerically by FVM, Tam-Thies turbulence model. The results show that small injection flow rates (less than 3%) can make sharp increases in both velocity and temperature decay rates at middle Mach number. Compared with the unforced plume, when the jet mass flow accounts for 1% of the main flow, the IR radiation intensity of the forced plume is reduced by about 15%; and when the jet mass flow occupy 3%,the IR radiation intensity of the forced plume is decreased by about 27%.
Output feedback eigenstructure assignment based on stochastic robustness analysis
Jin Xianzhe, Wu Sentang
2011, 37(4): 487-491.
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An approach for output feedback eigenstructure assignment(EA) of linear multivariable system with parameter uncertainty was presented based on stochastic robustness analysis (SRA), which was used to solve the problem of the eigenstructure robustness. With SRA, the robustness measures of closed-loop control system could be achieved accurately. And the direct relationship between the control system design specifications and the design parameters was established. The optimization algorithm was employed to maximize the control system robustness through trading off between the stability and the performances. At last, SRA-EA was applied to the decoupled design for lateral control system of the hypersonic vehicle. The numerical simulations demonstrated the effectiveness of the presented approach.
Life prediction of product based on degradation amount distribution time series analysis
Wang Li, Li Xiaoyang, Jiang Tongmin
2011, 37(4): 492-498.
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For the problem that traditional life prediction methods described product degradation stochastic process inadequately using monotonous regression function,the non-stationary time series types of different degradation amount distribution parameters estimation was analyzed based on product degradation amount distribution at each time.Different parameters estimation was modeled respectively using non-stationary time series analysis method.Hence,a realistic product life and reliability prediction method based on degradation amount distribution time series analysis was proposed. A degradation test of a certain electronic product was conducted,and product life and reliability were obtained by the suggested method. The results show that the suggested life prediction method is more reasonable than traditional life prediction method.
Hydraulic system modeling language base on finite volume and implementation
Xing Qiujun, Jiao Zongxia, Wu Shuai
2011, 37(4): 499-504.
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To achieve schematic-oriented modeling directly on the hydraulic system, a new modeling language based on finite volume and a new set of rules to describe the modeling language were proposed, also the corresponding procedural method was described. Based on the modeling language, the topology of the hydraulic system was abstracted to graphical structure with volume nodes and elements nodes. The components model was defined and packaged independent. Coperating with describing rules, the connection matrix of volume nodes and components would be generated. The overall system model was constituted by all nodes and the connection matrix. By typical intelligent hydraulic pump modeling process, the validity and effectiveness of this modeling language was proved. The results showed that by this language, the topology was established easily, and schematic-oriented hydraulic system model was generated conveniently.

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