2010 Vol. 36, No. 5

Display Method:
Analysis on power recovery rate of the accelerated life test bed for the airborne hydraulic
2010, 36(5): 505-508.
Abstract:
In view of the accelerated life testing(ALT) for the airborne hydraulic has the characteristics of long test time and many power consumption, the mechanical compensation method to save energy was brought forward based on the power recovery principle. To realize power recovery, the flow matching condition which the test system must meet was studied. In theory, the calculating formula of the power recovery rate was derived, the influencing factors of the power recovery rate was analyzed. Through the test method, the influencing factors of the power recovery rate under the different conditions was verified, the reason for the inconsistent power recovery rate of the actual and the theoretical was also analyzed. The result indicates that the type of the power recovery method can significantly reduce the energy consumption during the ALT and has obvious energy saving effect.
Dynamic characteristic analysis of the gas film seal in counter-rotating shafts
2010, 36(5): 509-512.
Abstract:
Two stiffness and damping of the seal were calculated with the finite element method; the influence of the racetrack and the primary seal ring mass on the stiffness and damping was analyzed; then the vibration process of the seal caused by transient force was analyzed. The results declare that film thickness has a great influence on the stiffness and damping, especially when the thickness is less than 5μm; free vibration frequency of the system is mainly decided by the mass of the seal racetrack, and the effect of the primary seal ring mass on free vibration frequency is neglected; the different ratio of the system mass with the same racetrack mass has a little influence on the convergent time of the vibrating system.
Mechanism optimization of bionic cockroach robot based on locomotion dexterity 
2010, 36(5): 513-517.
Abstract:
The oval body configuration based on the characteristic of mechanism and the locomotion dexterity of a bionic cockroach robot was chosen. The workspace of a single leg and the dexterity denoted by the reciprocal of condition number of the whole bodys Jacobian matrix were used to optimize and configure the parameters of mechanism. The optimal length ratios of links were decided via dexterity and reliability. The parameterization simulation model was built in ADAMS.Simulation result according with the analysis by theory indicates that the optimization and configuration are correct and suitable. This method provides a basis for the development of actual proto and the control of bionic cockroach robot. It also can be referable for the design of other hexapod robots.
Tolerance optimization based on neural network and genetic algorithm
2010, 36(5): 518-523.
Abstract:
Taking into account the highly nonlinear relationship between the cost and the tolerance in the product manufacturing process, a method based on the neural network in conjunction with the genetic algorithm was proposed to solve the tolerance optimal issues. The method integrates the advantage of the genetic algorithm, which can obtain the optimal result in a largescale solution space using the probability searching strategy and the strong robustness, and the superiority of the neural network that can solve the highly nonlinear problem. In the optimization process, the neural network was trained using sample data to simulate the tolerancecost function at first and get a function relationship with the black box feature between the cost and the tolerance. And then the genetic algorithm was introduced to optimize the tolerance allocation by taking the results of the trained neural network. It takes the functional requirements and the standard tolerance grades as constraints as well as the minimum of the component cost as the objective. A tolerance optimization system based on a C+[KG-*3]+ library and the Matlab was designed. Finally, an example of the latching shaft and hook mechanism component of the aircraft cargo door demonstrated the method. The analytical result proves that the new method can produce the tolerance optimization economically and accurately, and has an advantage over traditional methods.
Error predicting for material Brinell hardness measurement of  poor information based on grey bootstrap method
2010, 36(5): 524-528.
Abstract:
Error predicting for material Brinell hardness measurement of poor information is a common problem in the field of hardness measurement. Only small sample measurement data obtained for Brinell hardness measurements are destructive. Different from statistical methods, a novel poor information Brinell hardness measurement error prediction method was presented, which was based on grey system theory and bootstrap theory. After calibrated all measurement error sources, all measurement error transfer coefficients should be calculated and the calibration data of error sources should be sampled in terms of bootstrap theory. The predictions of calibration data of all error sources were gained by a grey Bootsrap fusion model. The error prediction values were obtained for material Brinell hardness measurement of poor information in terms of error combination principle. In an example of a general Brinell hardness measurement, the predicting Brinell hardness measurement errors acquired by this novel proposed method and the actual measurement errors were shown to be in a good agreement with each other, and the validity of the proposed method was also represented.
Large eddy simulation of film cooling under rotating condition
2010, 36(5): 529-533.
Abstract:
Large eddy simulation was used to predict flow and heat transfer of film cooling on a flat plate perforated by 35° streamwise inclined cylindrical hole of 4mm under stationary and rotation conditions. The predicted nondimensional velocity profiles compared well with available experimental data in stationary case, justifying present simulations. But the discrepancy of temperature predicted by present work and that in reference numerical work was obvious. After introducing system rotation at the same blowing ratio and Reynolds number, vorticity distributions showed increasing distinctness along with the increased angular velocity. And the trajectory of shear layer between mainflow and coolant deviated towards spanwise under rotation condition, leading to the asymmetry of the counter rotating vortex pair after coolant injection. Furthermore, the dynamics of coherent structures detected in three cases also demonstrate the rotation effect, which significantly influences the mixing of mainflow and coolant and the consequential heat transfer.
Genetic algorithm analysis for multisatellite TT&C scheduling
2010, 36(5): 534-539.
Abstract:
A multi-satellite tracking telemetry and command(TT&C) scheduling model was proposed, guiding by the engineering requirement, and genetic algorithm was used to solve the problem,which aimed at solving the multisatellite conflict problem. Based on the global and local searching strategies, taking usable time windows as object, all usable time section encoding(AUTSE) and cooperative coevolution GA encoding(CCGAE) were designed, the processes and operators of the algorithms were described, then the efficiencies of the two encodings were analyzed. The solution quality and time spending performances of the two encodings were examined through simulation, and the applicable scope of the two encodings and corresponding searching strategies was summarized. The system adopting above results has been applied to the auxiliary decision-making of spaceflight top-level design successfully.
Numerical control reconfigurable compliant tooling technology
2010, 36(5): 540-544.
Abstract:
Jig is an important process tooling in aircraft assembly. In order to change the traditional “one to one” assembly mode that one rigid jig only assembles one panel components in aircraft assembly, reduce the number of tooling and develop digital flexible assembly, NC(numerical control) reconfigurable compliant jig that contour board location point is reconfigurable was developed. Its fundamentals and key technologies in design was introduced. Field bus technology was used to make contour board location points numerically reconfigurable. Based on the redevelopment of CATIA, special software to compute reconfigurable data was developed. A whole digital transfer of reconfigurable data was brought about in NC jig application process. The application in practice indicated that NC jig worked stably and reliably as well as meeting accuracy requirements. The aircraft assembly jig was digitalized and flexible, which is of great significance for further study in flexible tooling technology in aircraft digital assembly.
Decentralized optimal control of multiple heterogeneous UAVs in cooperative target tracking
2010, 36(5): 545-549.
Abstract:
The decentralized information fusion algorithms for multiple heterogeneous sensors platforms with different types and dimensions was developed to meet the needs of the target tracking with active and passive sensors. The decentralized information fusion algorithm was scalable, heterogeneous and reconfigurable. The performance cost function and constraints model of communication, collision avoiding and control for decentralized optimal control of multiple heterogeneous unmanned aerial vehicles(UAV) in cooperative target tracking were established to maximize the local information entropy obtained by information fusion and the quality of information observed by each UAV. The cooperative target tracking based on multiple heterogeneous UAV was implemented using decentralized model predictive control. The effects of imperfect communication on decentralized information fusion and cooperative control were investigated.
Program and scenario of manned spaceflight to Mars
2010, 36(5): 550-554.
Abstract:
A brief overview of research progress about manned spaceflight to Mars program in several countries was given. Investigation of some domestic and international programs and scenario of manned spaceflight to Mars was put up. Some fundamental and basic ideas about determination of future manned spaceflight to Mars were put forward. One of programs and scenario of general design, including trajectory and spaceship of manned spaceflight to Mars was discussed and put out. Especially, more important parameters of the total mission energy required and the total mission duration of the trajectory in several mission windows were calculated. The detail results of trajectory design, including transfer Mars injection, Mars orbit insertion, Mars surface descent, Mars surface ascent, transfer Earth injection, Earth orbit insertion and reentry Earth, and Mars spaceship design, including propulsion module, transfer habitation module, Mars landing module and Earth reentry capsule were obtained.
3D morphing method based on Kriging algorithm for surgical navigation
2010, 36(5): 555-559.
Abstract:
A set of preoperative CT reconstructed model can not be used in operating on individual patient in 3D surgical navigation systems. According to the problem above, a 3D bone morphing method based on Kriging algorithm was presented. Two point sets, one of which was acquired from physical space by the optical localizer and the other was from 3D model reconstructed by the marching cube method, were used to calculate the transformation matrix between the preoperative CT image space and the intraoperative marker space. Then 4 appropriate reference points were chosen to solve the equations based on Kriging algorithm, and the positions of points on CT model after deformation respect to the physical case were acquired. At last, precision analysis of morphing and evaluation experiment of knee joint navigation was carried out with CT and plastic model. The result shows that under this condition the final morphing accuracy is less than 1mm, and this technology can be used in operation evaluation of the anterior cruciate ligament navigation reconstruction.
Energy consumption analysis for pneumatic actuator and electric actuator
2010, 36(5): 560-563.
Abstract:
The energy consumption processes of pneumatic actuator and electrical actuator were analyzed. A calculation model of the energy consumption for pneumatic actuators was proposed. And two sets of actuators experimental system for pneumatic actuator and electrical actuator were built up. The large quantities of the experimental data were received from the energy consumption experiments of two types of actuator. The main results were gained through the analysis experimental data :①The pneumatic actuator is more energy-efficient than the electrical actuator on the condition of maintaining the load for a long time or the condition of unfrequent actuation. However, the electrical actuator is more energyefficient than the pneumatic actuator on the condition of frequent actuation. ②In a variety of operating conditions, the running power of the pneumatic actuator fluctuates slightly and the running power of the electric actuator has a great fluctuation.
Application of complete complementary sequence in MIMO radar
2010, 36(5): 564-569.
Abstract:
MIMO(multiple-input multiple-output)radar can effectively improve radar performance by transmitting orthogonal signals. While the conventional single sequence can not keep the complete orthogonality (the sidelobes of the auto-correlation and cross-correlation function equal to zero at all delays). In the context of the problem, in conjunction with the property of the complete complementary sequence, the ambiguity function of complete complementary sequence was derived. The results of the computer simulations show that the validity of the proposed ambiguity function. The radar velocity resolution based on complete complementary sequence was also analyzed. The application of complete complementary sequence in MIMO radar was studied and the MIMO radar signal model based on complementary sequence was established. It is demonstrated that the complete complementary sequence has the potential to significantly improve the MIMO radar performance significantly. And the rationality and validity of the complete complementary sequence applied in MIMO radar are proved.
Optimum design of accelerated life testing based on proportional hazards-proportional odds model
2010, 36(5): 570-575.
Abstract:
nformation based optimality criteria were adopted in the optimum design of accelerated life testing (ALT) based on non-parametric model. The optimum design of accelerated life testing based on proportional hazards-proportional odds model was processed for constant stress loading and step stress loading respectively. The optimum problem was established by defining Fisher information matrix and variance-covariance matrix based on log-likelihood function. These optimality criteria could improve the accuracy of model parameter estimates effectively and they avoided the drawbacks of the traditional optimality criteria which minimized the integral of asymptotic variance of a reliability-related function over a specified time period under normal operating condition that might result in different optimum solutions with the varying of the length of the time period. Numerical examples were given to demonstrate these methods.
Reliability integrated compliance testing plans based on decision making level data fusion
2010, 36(5): 576-579.
Abstract:
The reliability compliance test is the test inspected reliability level against the requirements, and is the important reliability activities. It is a formidable task for some expensive or high reliability products according to classic reliability compliance testing plans to demonstrate reliability. Based on these problems, the basic probability assignment was built using varieties of development information, including development data, reliability assessment result and expert experience. And the reliability integrated compliance testing model was given for success ratio applying the evidence theory. In the meantime, the character of this reliability integrated compliance testing model was researched. The existence of the integrated compliance test plan was evidenced, and the choosing principle was discussed. This model can avail diversiform information, and the integrated compliance test plan serving difference distribution and difference information can derive form this model. The target to reduce the samples by the use of multifarious development information was illustrated by instance.
Modulation method for stabilizing zero-bias of FOG during warm-up
2010, 36(5): 580-583.
Abstract:
To solve the zero-bias fluctuation problem of fiber-optic gyroscope (FOG) during its warm-up, the influences of initial alignment of 2π voltage and anterior gain fluctuation on the zerobias of FOG were analyzed, respectively. A novel hybrid modulation method, namely four-state modulation method was proposed, by which the drawback of conventional square wave modulation method can be overcome. Due to this proposed fourstate modulation and demodulation method, the rapid adjustment of Y waveguide 2π voltage was realized, which reduces the adjusting time of the warm-up from 5 minutes to 1 second. Owing to the analysis in the frequency domain, it was presented that the proposed four-state modulation and demodulation method can also suppress the crosstalk induced by modulation and suppress the influence of the anterior gain on the zerobias fluctuation. As a result, the change of the anterior gain fluctuation induced zero-bias of FOG during warmup is improved from 0.03(°)/h to 0.01(°)/h.
Method for measuring recovery time of digital television receiver
2010, 36(5): 584-587.
Abstract:
Recovery time of digital television (DTV) receiver is an important indicator of DTV service quality but the recovery time can not be measured directly with existing equipments. A new method was presented which measure the recovery time by bit error rate (BER) tester and impulse noise source through a series of the errored seconds caused by impulse noise. Different from the traditional way, a random trigger of pulses was used in this method, which resulted that the estimation of recovery time was not associated with the pulses start time. Without limit of the impulse noise length, the method can be used for measuring recovery time of the longer timeinterleaver transmission systems. The recovery time measured in this method is with a precision of 0.1s, which is an order of magnitude lower than past experiments. The effect of experimental parameters on recovery time was analyzed with the test result in a digital terrestrial multimedia broadcasting (DTMB) receiver.
On coupled bending and torsion of rotor with nonlinear oil-film force
2010, 36(5): 588-591.
Abstract:
A mathematical model of a rotor with nonlinear oilfilm force was presented, in which coupled bending and torsion were considered. The unbalance response of the rotor was numerically calculated by Rugge-Kutta method, and the bifurcation diagrams and waterfall plot were obtained to analyze dynamic characteristics of the system. The results reveale multiform complex nonlinear dynamic behavior of the rotor, that comprises periodic, double periodic and quasiperiodic motion. By comparing with dynamic characteristic of the system without considering the interaction of bending and torsion, it shows that bending vibration is heavily affected by the interaction of bending and torsion when rotating speed is near by the critical speed.The numerical study illustrated characteristics of torsion with increasing rotating speed. The results can provide a deeper understanding to coupled bending and torsion of the rotorbearing system.
Three dimension numerical simulation of flow/solid coupled heat
2010, 36(5): 592-595.
Abstract:
To understand the complex fluid flow and heat transfer in heater nozzle, three dimensional fluid/solid coupled heat transfer method was employed. Governing equations for hot gas, solid wall and coolant were established respectively, radiation heat was added into the energy equation as a source of heat radiation. Firstly the heat transfer of the AEDC(arnold engineering development center)  nozzle was simulated in this method; the coolant temperature rise and the heat flux distribution were found to agree very well with the experimental results. This shows the coupled method is valid in solving conjugate heat transfer problem. Then the method was used to analyze the heat transfer in heater nozzle of a scramjet test facility. When the water flow rate is 2.0 kg/s,the heater nozzle is well worked. The effect of the radiation heat cannot be ignored.
Influence of canard wing and strake on aerodynamic characteristic of  chined forebody at high AOA
2010, 36(5): 596-600.
Abstract:
The influence of canard wing and strake on aerodynamic characteristic of chined forebody was studied by surface pressure measurement and particle image velocimetry(PIV) flow measuring systematically.It shows that there is only a little effect of canard wing on the flowfield around nose area under 50° angle of attack(AOA). If angles of attack are larger than 50°, the normal forces on nose region  decrease sharply and influenced region by canard wing is enlarged toward the nose region with increasing AOA. The normal force in the canard wing region is increased sharply by setting canard wing. The flowfield on the strake region is improved and the normal force on the strake region is increased by setting the strake. If the canard wing and strake are set simultaneously, the flow behaviors in nose and canard regions will be dominated by canard wing and one in strake region will be dominated by strake.
Antenna sensor based on PSD and application mobile robot
2010, 36(5): 601-605.
Abstract:
In the environment with limited light, robots obstacle avoidance could not be realized if the vision sensor was used only. In order to deal with the problem, an antenna sensor system was designed. Position sensitive detector (PSD) was used as the sensing instrument and a laser pointer was attached to the antenna end, from which the laser was shot out to the other side. Following this approach, a new antenna mechanical structure was proposed to make the installation simple and to reduce the assembly error. Two new methods were proposed to detect the angle between the body and the wall. Advantages and disadvantages of the two methods were discussed. The robot could walk along the wall by the two methods and the effectiveness was experimentally demonstrated. What caused the error was analyzed at last.
Ultra-tightly coupled navigation system design based on SINS aiding GPS tracking loops
2010, 36(5): 606-609.
Abstract:
In order to improve the tracking performance of global positioning system (GPS) in high dynamic environment and provide reliable calibration information for strapdown inertial navigation system (SINS), the scheme of SINS aiding GPS ultratightly coupled navigation was presented. Considering  the poor tracking performance of the carrier phase lock loop (PLL) in high dynamic applications, Doppler frequency derived from SINS parameters was provided for PLL, and so the effect of vehicle dynamics on PLL was decreased. Additionally, in order to eliminate the measurement correlation caused by introducing SINS aiding information, the relationships between PLL errors and SINS errors have been established and PLL errors were appended to the system state vector. Finally, the simulations indicate the ultra-tightly coupled system can not only enhance the antijamming capability and the dynamic tracking performance of the tracking loops effectively, but also improve the error estimating precision of the integrated Kalman filter significantly.
Effect of titanium on high temperature oxidation esistance of niobium based alloy
2010, 36(5): 610-613.
Abstract:
As a criterion of the integrated oxide on pure metals, pilliingbedworth ratio (PBR) is one of the main reasons of generating the growth stress in the scale. In order to evaluate the value of PBR for the oxide formed on alloys, a simple model had been established; and the value of Nb2O5,Ti2Nb10O,TiNb2O7 and O2had been evaluated. The results show tthat high temperature oxidation resistance of the alloy is improved by applying with Ti. Type and content of the oxide, which cause the PBR of the scale alter are changed as the content of Ti increases. It is concluded that the PBR of the scale has been decreased accompanied by increasing of Ti, making the scale not be cracked, which induces the scale and has a better protective effect on the matrix.
Multiple scattering RCS computation of complex targets on GRECO
2010, 36(5): 614-616.
Abstract:
The multiple scattering of the complex targets has great influence on the accurate radar cross section(RCS) prediction of the target. A new method  based on the graphic electromagnetic computing(GRECO) platform utilized the visualization character of the GRECO. The pixel was regarded as basic computation unit in this method. Employing geometric optics and physical optics in the electromagnetic computation theory, the RCS computation of the complex target was achieved after the acquisition of the pixel geometrical information and the search of the pixel pairs which meet the criterion of the multiple scattering. The computation examples of the dihedral corner reflector and the missile which are modeled with AUTOCAD software are given. Excellent agreement with the data from other literature indicates that the method has practical engineering value.
Active-disturbance rejection control of multi-redundancy brushless DC motor
2010, 36(5): 617-621.
Abstract:
To overcome the effects of the parameter variations, cogging effects, load disturbance and degrading redundancy and achieve high-performance servo control, an active-disturbance rejection controller (ADRC) of multiredundancy brushless DC motor servo system was presented. The position controller was composed of tracking differentiator (TD), extended state observer (ESO) and nonlinear state error feedback control(NLSEF) law. The TD provided a transition process for reference position, which overcome the contradiction between responding speedily and overshooting smally. The ESO observed and compensated the disturbance caused by parameter variations, cogging effects, load disturbance and degrading redundancy. The NLSEF implemented a nonlinear control and led to accurate results. Simulation results demonstrate that this controller has good dynamic and static performances and strong robustness against disturbances.
Factor analysis used in pulsed infrared thermographic NDT
2010, 36(5): 622-626.
Abstract:
 To improve the detection capability of pulsed thermography (PT), factor analysis algorithm was applied to image sequence processing in pulsed infrared thermographic nondestructive examination(NDT). The principle of factor analysis was introduced and the procedure of image sequence processing and reconstruction was described. In order to illustrate the validity of this method, a glass fiber reinforced plastic sample with artificial internal defects was tested by PT. It is shown that the common factor images can be used to improve the recognition of flaws; factor analysis is more flexible than principal component analysis (PCA); the reconstructed image sequence can improve the defect’s signal to noise ratio(SNR) and decrease the nonuniform heating effect, thus the detection capability of PT is enhanced.
SLD collimation system design for free-space optical transceiver module of fiber optic gyroscope
2010, 36(5): 627-630.
Abstract:
With the development of highly accurate and compact fiber optic gyroscope, based on the special demands of compactification and integration to the transceiver module used in the fiber optic gyroscope and the characteristic of  superluminescent diode(SLD) beam, an array of asymmetrical cylindrical lens collimation optical system was proposed, which could be used to form collimating and spherical the beam. The collimation optical system was thoroughly studied. The configuration parameters (i.e. curvature, thickness) were minutely calculated using the analytical method of both the geometry and matrix optics. Furthermore, in the use of the analytical method of matrix optics the optical transmission matrixes were deduced to optimize the configuration parameters of cylindrical lens. The system was simulated in CODE Ⅴ software and the conclusion was elicited. Theoretically, the radiation angle of SLD beam can be compressed under 0.05 mrad.