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2013 Vol. 39, No. 9

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Dynamic modeling and stability analysis for underwater craft with wing
Ye Chuan, Ma Dongli
2013, 39(9): 1137-1143.
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The underwater craft with wing has a large lifting surface. The rolling movement is one of its basic maneuver models. The dynamic derivatives of an underwater craft with wing were studied using the computational fluid dynamics(CFD) method. The result shows that the viscous force and the interference of the wing on the body and the tail are important for the acceleration derivatives in the heave, roll, and pitch directions. The acceleration derivatives could not be simplified as additional mass coefficients. The dynamic and kinematics equations were linearized using the small disturbance hypothesis. The equations were divided into longitude and lateral-directional equations. The dynamic stability of an underwater craft was studied by calculating the modes of the small disturbance equations. The dynamic model and stability analysis method could be used for dynamic stability analysis and motion control system design for the underwater craft with wing.
Influence of adhesive properties on tensile behavior of scarf repaired laminates
Cheng Xiaoquan, Zhao Wenyi, Gao Yujian, Bao Jianwen
2013, 39(9): 1144-1149,1162.
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Tensile failure behavior of scarf repaired composite laminates was studied with non-linear three dimensional finite element modeling. The finite element method(FEM) results are in good agreement with the testing results, which verifies the established model validity. Based on it, the tensile strength of scarf repaired laminates was calculated and the failure mechanism was analyzed. The influence of mechanical properties of the adhesives on the tensile behavior of scarf repaired composite laminates was studied. Finally, the principle of adhesive materials choosing for a scarf repaired composite laminate and the ideal adhesive-s characters were concluded. The results can provide references for the repairable design of composite structures, as well as the research and development on adhesive materials for scarf repaired composites with butt joints.
Analysis on acquisition method in spread spectrum TT&C system
Feng Wenquan, Liu Xi, Li Chunsheng
2013, 39(9): 1150-1156.
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In spread spectrum telemetry, tracking and command (TT&C) systems, the integrated baseband equipment has been occupying an important role due to its high flexibility. Limitations of traditional methods were analyzed concerning the complex demands of the integrated baseband equipment. On this basis, a new acquisition method was put forward. The dynamic range of received carrier was divided into sub-intervals, and then dual down-conversions and sectional accumulations were adopted to accommodate larger doppler frequency. The deterioration of acquisition performance in non-coherent modulation systems was solved by a nonlinear transformation as well. Theoretical analyses and simulation results on the proposed method were given, which can provide reference for the design of integrated baseband equipments and for parameter determination in TT&C tasks.
Observability analysis of GPS/SINS ultra-tightly coupled system
Zhou Weidong, Cai Jianan, Sun Long, Zheng Lan
2013, 39(9): 1157-1162.
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The filter precision depends on the observability of system states. Various approaches were proposed to analyze the observability of the linear system states. Among those approaches, singular value decomposition (SVD) was commonly used to analyze the system beforehand owing to its computational simplicity. However, the measurement equation of global positioning system/strapdown inertial navigation systems (GPS/SINS) ultra-tightly coupled system based on the concentrated filter structure was nonlinear, which made it difficult to analysis the system observability. To solve this problem a linear measurement equation was derived. This GPS/SINS ultra-tightly coupled system model was proved to satisfy the piece-wise constant system (PWCS) theorem and the states' observability of the system were calculated based on the theory of SVD. The results show that the observability of states is affected by the maneuverability of carrier. The stronger maneuverability is, the more observable states are, the higher observability is.
Application of Mie-scattering theory in measurement of mean droplet diameter
Chang Shinan, Guan Zhangjie, Wang Chao, Zhuang Weiliang
2013, 39(9): 1163-1167,1191.
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In an ice wind tunnel experiment, in order to simulate the experimental environment more accurately, the diameter of droplets jetted from the nozzle need to be measured accurately accordingly. A set of laser device and drop diameter calculation program based on Mie-scattering theory were developed. In the environment of droplet flow field, the laser beam became scattered, experiments were repeated to obtain multiple moments of the scattering intensity distribution figures in interval of. The calculation program developed was applied to calculate the scatter intensity distribution of the figures. The mean diameters of water droplets in the same section but at different time were obtained. The Newton interpolation method was applied to interpose the data of multiple sets of the mean droplet diameters and based on the curves obtained by fitting the diameter data of the cross at different time, the average value of the integration which was considered to be the mean droplet diameter would be obtained. A humidifier was used to investigate the feasibility of the code. Good agreement between the prediction and the data provided by the product description show that the measurement device and calculation program is feasible.
Mechanical principle of the deploying mode for coilable mast
Han Jianbin, Wang Xinsheng, Ma Haibo
2013, 39(9): 1168-1173.
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The coilable mast is a kind of space mast, and it can be used as many deploying mechanisms such as solar array, solar sail and detecting arm. The coilable mast has two deploying modes: local coil mode and helix mode. Based on the coilable mast with triangle-batten-form and hinges, the principle of the local coil mode was described. Firstly, because of the constant length of the diagonals, the batten deforms and has a maximum deformation. Then, after construction and simulation of the model in MSC.ADAMS, the effect of the batten bending stiffness was studied. With that work, this conclusion was obtained: the deploying mode is decided by two factors: the compressed ability of longeron on the batten of the second layer and the bending resistance of batten. This conclusion was verified with simulation of the coilable mast model in MSC.ADAMS. After analyzing the deformation of longeron using the Kirchhoff dynamics of thin elastic rod, the relation between the design parameter of coliable mast and the deploying mode was obtained. That result is helpful in the coilable mast design.
Fault diagnosis for sensors and components of aero-engine
Li Yebo, Li Qiuhong, Huang Xianghua, Zhao Yongping
2013, 39(9): 1174-1180.
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According to local learning and ensemble learning technologies, a method for sensors fault and abrupt components fault diagnosis of aero-engine was proposed based on support vector machine-extreme learning machine-Kalman filter (SVM-ELM-KF). The training approach of improved recursive reduced-least squares support vector regression (IRR-LSSVR) was extended to classification machine to distinguish sensor faults and component faults. The training method makes the classification machine have better sparsity. Considering sensors fault, the ELM was used for fault location. For components fault, the improved KF was adopted for health parameters estimation and fault location. Simulation results show that the proposed method for fault diagnosis can distinguish sensor faults and abrupt component faults accurately, and locate the faults effectively. That is, the proposed method is valid.
Design of fuzzy T-S model of unmanned aerial vehicle in full envelope
Liu Zhi, Wang Yong
2013, 39(9): 1181-1186.
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The method of constructing fuzzy T-S model in full envelope was designed for the integrated flight control of unmanned aerial vehicle (UAV) in entire envelope. Based on the local linearization of non-affine system, the design of fuzzy T-S model was transformed to the optimization of the centers and width of membership functions, with the weighted approximation errors of the stability and handing performances of UAV as cost function. The global optimization was conducted via extension of fuzzy sets of premise variables according to the sensitivity, providing the number of fuzzy rules and initial value of membership functions. Fast local optimization was performed employing Levenberg-Marquardt algorithm with the heuristic modification of regular factor. The example shows the algorithm converges rapidly, and that the fuzzy T-S model constructed realizes high-precision approximation of stability and handing performances of UAV in full envelope with less fuzzy rules, which is suitable for the integrated control of UAV in full envelope.
Failure analysis of reusable rocket engine coolant passage
Yang Jinhui, Chen Tao, Jin Ping, Cai Guobiao
2013, 39(9): 1187-1191.
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Through the creep nonlinear thermal-structure analysis of the reusable combustion chamber coolant passage under cyclic thermal and mechanical loading, comparison between kinematic and isotropic hardening results was made to study the hardening influence. Basing on those cyclic structure results, the "dog house" failure model of coolant passage was implemented. Results indicate that the thermal and structure environment could be improved by introducing materials with similar thermal conductivity for the jacket and inner wall and optimizing the geometric model; the kinematic and isotropic hardening results were similar in illustrating the development of stress and strain under cyclic loadings, whereas at the remaining strain variance of approximate 0.06%; the strain hardening effect was obvious in those cyclic loops which was analogous each cycle and right moved, and the fatigue damage and creep damage were determined respectively by cyclic strain and stress.
Landing stability analysis of the lunar lander based on Monte Carlo approach
Song Shunguang, Wang Chunjie
2013, 39(9): 1192-1196.
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A multi-body touchdown dynamics simulation model was established for predicting landing performances of the lunar lander. Because of the uncertainty of the landing site and initial landing conditions of the lander at touchdown, a Monte Carlo dynamic analysis was performed to study the landing stability of the lunar lander. A stopping rule based on the relative error of the mean estimate was adopted for determining the run length of the Monte Carlo simulation. Through the landing simulation experiments on the lunar surface with a certain slope, statistical results of the landing performance parameters such as the means, variances and corresponding confidence intervals were obtained and the reliability for stable landing was finally computed.
Dynamic modeling and optimization of a typical disk-type check valve
Zhang Rui, Wu Shuai, Jiao Zongxia
2013, 39(9): 1197-1202.
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The characteristics of disk-type check valve are particularly sensitive to its reed parameters. Taking a typical reed with three curved-beams as an example, a general modeling and optimization method was investigated to improve the valve dynamic performances. An interpolation model of the reed relating to its beam width, radian and thickness was derived based on the deformation theory of curved-beams. The model parameters were obtained via finite elements method. Based on the reed model, a dynamic model of the check valve was built. With a sinusoidal pressure input, the reed parameters were optimized for the largest net flow rate output via the particle swarm optimization method. With the raise of frequency, the best reed thickness increases, but the net flow rate decreases. The experimental results of the valve match well with those of simulation. The above method is simple but practical, which contributes to the reasonable design of disk-type check valves in engineering.
Random error suppression technology of rotating FOG inertial navigation system
Zhou Bin, Wang Wei, He Xiaofei
2013, 39(9): 1203-1207.
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The impact of the gyro constant drift and accelerometer constant bias to the inertial navigation system (INS) can be reduced by rotation modulation technology, but the gyro random drift and noise can not be inhibited. The errors of INS will divergence under action of random disturbances, which affects the long-term ability to navigate. The damping technology to inhibit random error interference was concerned, and a damping rotating fiber optic gyro (FOG) inertial navigation system was presented. Using the damping technology the affect of random noise to navigation system accuracy was suppressed. Simulation results show that the single axis rotating FOG inertial navigation system precision is improved by more than one times with damping technology. When higher precision instrument is adopted, it will be more obvious for suppress effect of random error.
Quantitative analysis method for mechanism severity of whole product
Yuan Hongjie, Zhang Ze, Wu Hao
2013, 39(9): 1208-1211.
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Due to qualitative method was used to analyze whole products with characters of complex failure mechanism and small samples, Bayesian method was proposed for quantitative analysis of failure mechanism severity. Firstly, Bayesian posterior density function was determined by prior information described by dirichlet distribution and failure data. Then full condition distribution of failure frequency and Bayesian estimation were obtained by Slice samplings and Gibbs samplings separately. Furthermore, failure mechanism severity was analyzed quantitatively. Finally, under the premise of failure mechanisms of an optical fiber connector have been analyzed clearly, the main failure mechanisms were confirmed by failure modes, mechanisms and effects analysis(FMMEA) and Bayesian method respectively. The results showed that severity of the failure mechanism which did not appeared on site was considered by Bayesian quantitative analysis method, the main failure mechanisms were more credible than the results based on FMMEA.
Analysis and computation on electromagnetic backscattering scattering coefficient of two-dimensional fractal sea surface
Wang Chungang, Feng Wenquan, Li Chunsheng
2013, 39(9): 1212-1217.
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Based on the existing two-dimensional fractal sea surface model, a novel electromagnetic backscattering coefficient model was derived in the HH and VV polarization mode, respectively. Average statistics of the backscatter coefficient from all resolution cells in some wavelength regions was computed and affect of seawater permittivity, electromagnetic waves incident angle, incident frequency, and wind speed and direction on the backscattering coefficient was analyzed in the time domain. The fractal dimension of the backscatter coefficient was estimated by box-counting. Numerical analysis method was adopted to demonstrate that the real and imaginary parts of the backscattering coefficient are fractal and their fractal dimensions are both equal to the fractal dimension of the backscattering coefficient or the two-dimensional fractal sea surface. Thus it indicates that the radar echo from the sea surface is also fractal, and provides an important method for the use of the fractal theory in sea weak target detection.
Experimental studies on fatigue crack growth rate at elastic-plastic state of aeronautical aluminum alloy
Zhang Jikui, Wu Liesu, Ma Shaojun, Liu Jianzhong
2013, 39(9): 1218-1221,1227.
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Studying the crack propagation behavior of the thin-walled structure with long cracks is very significant for ensuring the safety of the airframe. The specimen and fixture of aluminum alloy wide plate was designed for fatigue crack propagation rate (da/dN) testing. The fatigue crack growth rate was tested for 2024-T3 and 7075-T6 aluminum alloy at elastic-plastic state. The relationship between the range of stress intensity factor (ΔK) or crack central line displacement (Δδ) and da/dn was discussed to describe the crack propagation behavior of aluminum alloy. The experimental results show that under medium-high loading, the long crack of wide plate grows quickly; the da/dN~ΔK curve turns obviously at this stage; the crack growth behavior cannot be expressed as Paris law. At the final stage, there is a linear relationship between Δδ and da/dn in the logarithm coordinate. The crack propagation behavior of aluminum alloy at elastic-plastic could be described by Δδ~da/dN curve.
Thermal control design and analysis for laser communication terminal
Meng Henghui, Tan Canghai, Geng Liyin, Li Guoqiang
2013, 39(9): 1222-1227.
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Laser communication terminal is a new signal transmission carrier. The equipment-s optics-device parts bring high heat dissipation, and require higher equality and stability of the temperature. It is a challenge for thermal control. According to the characteristic of the laser communication terminals and the rule of outer space heat flux, a new way for thermal control was designed as the following: heat-conducted plate and heat pipe were adopted for heat transfer of high heat-flux parts, and high precision temperature control methods were applied for key parts. A numerical simulation was investigated in uttermost cases by thermal desktop analysis software, and the results prove the design correct.
Coning compensation algorithm with angular rate considering gyroscope frequency characteristics
Chen Yu, Zhao Yan, Li Qunsheng, Wu Hui
2013, 39(9): 1228-1232.
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Focusing on the gyroscopes- output is angular rate and has a certain frequency characteristics, a coning compensation algorithm considering the gyroscopes- frequency characteristics with angular rate as input was presented. The ideal and computed rotation vector increment was derived in the attitude update interval under coning motion. The coning compensation algorithm coefficients were computed to minimize the nonperiodic term difference between the ideal and computed rotation vector increment. The optimal coefficients were defined to be the sum of the values that exist for perfect angular rate input and an adjustment that accounts for the frequency characteristics. The formulized approach for the optimal coefficients with arbitrary samples considering frequency characteristics was obtained. Simulation results show that the accuracy of the algorithm can be improved effectively as compared with the conventional ones.
Dimensionless study on outlet torque characteristics of an air powered engine
Yu Qihui, Shi Yan, Song Rongzhi, Cai Maolin
2013, 39(9): 1233-1237.
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Aiming at the process of an air powered engine, the energy equation, gas state equation, continuity equation and momentum equation were used to set up non-linear differential equations of an air powered engine(APE). By selecting the appropriate reference values, the basic mathematical model was transformed to a dimensional expression. Using MATLAB/Simulink for simulation, the dimensionless outlet torque characteristics of APE were obtained. Through analysis, it can be seen that the dimensionless outlet torque of APE was mainly determined by the dimensionless crankshaft speed, the inlet effective area scaling coefficient, the outlet effective area scaling coefficient and the duration angle. The dimensionless outlet torque could be regulated by charging the inlet effective area, the outlet effective area and the duration angle to fit the change of crankshaft speed.
Timing analysis system for real-time industrial Ethernet EtherCAT
Huan Ji, Liu Zhe, Jin Yang, Hu Xin
2013, 39(9): 1238-1242,1248.
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The characteristics of real-time industrial Ethernet(RTIE) were studied. A timing analysis system was proposed consisting of probe, monitoring PC and Timing-Analyzer software. Each of the passing frames was captured by the probe which includes one field-programmable gate array(FPGA) core. The information of the original frame was extracted and encapsulated in the probe frame, which was transmitted to the monitoring PC together with the original frame. The probe frame is one specific Ethernet frame format for the timing or functional analysis of RTIE. The information contained in the probe frames was parsed and synthesized by the timing-analyzer. The graphical results were displayed according to the user-defined parameters. A verification system based on EtherCAT was presented. The implementation shows that the on-line acquiring and off-line analyzing for RTIE were carried out by the proposed timing analysis system. The graphical result is clear and useful for determining the timing characteristics of the communication links and devices.
Analysis on mathematical modeling for multi-source and multi-outlet complex compressed air pipe network
Gai Yushou, Shi Yan, Cai Maolin
2013, 39(9): 1243-1248.
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Array was used to build the structure mathematical model of the multi-source and multi-outlet complex compressed air pipe network. With the topology structure of the pipe network, the pressure dropping law and the linkage characteristics between the pressure and the flow of the compressed air in the pipe, the fluctuation of the pressure and flow of the air was obtained. With the model, the possible fluctuation of the pressure or the flow could be predicted rapidly, which could provide a solution for the accurate forecast of the volume of the compressed air in the network. With the accurate data of the pressure and flow, the energy efficiency of the whole pipe network can be analyzed too.
Active integrated devices PDN vector fitting modeling method
Chen Xi, Xie Shuguo, Du Wei, Wei Ying
2013, 39(9): 1249-1253.
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Based on the vector fitting principle and circuit theory, a kind of active integrated device wideband circuit modeling methods for electromagnetic magnetic compatibility(EMC) simulation was proposed. The port parameters in DC bias obtained by measurements using vector fitting method were transformed into pole-residue and time domain state equation model; then a circuit netlist model which compatible with simulation program with integrated circuit emphasis(SPICE) was obtained, the netlist can replace the target chip used in circuit simulation. Finally, this method was used for sample chip power distribution network(PDN) module and was compared with the IC electromagnetism modeling(ICEM) modeling. The results show that the vector fitting model has a wider bandwidth and smaller model errors.
Effects of jet injection angle in a flat transverse flow
Wu Meng, Eriqitai Wang, Mengjie, Du Jiangyi
2013, 39(9): 1254-1258.
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The computational and experimental studies were conducted to investigate the effects of the jet injection angle on the flat flow structure and its operating characteristics, the conclusions were made to apply on the fluidic control vectoring nozzle. The experiments were performed in a small wind tunnel test bed. The schlieren method was used to observe the flow structure and the wall pressure distribution of the test model was measured by the static pressure measuring point. The results show that the computational and experimental results are in good agreement. Increasing the transverse injection angle can improve the jet upstream of the separation zone, and make the bow shock position closer to the top. However, the change of the flow structure is no longer obvious when the transverse injection angle big enough. The numerical simulation of fluidic control vectoring nozzle indicates that the increase of the transverse injection angle can improve the thrust vectoring performance effectively. To be specific,the thrust vectoring performance raises by 28.3% when the transverse injection angle change from 90° to 130°, on the conditions that NPR equaled 4.6 and SPR equaled 0.7.
Fast algorithm of Gram-Schmidt regression method
Wang Huiwen, Xia Bang, Meng Jie
2013, 39(9): 1259-1262,1268.
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A new multiple linear regression method was proposed which can screen the variables fast. In the modeling process, not only can it screen variables containing best information to explain the dependent variable, but also distinguish and test redundant variables in the model based on Gram-Schmidt orthogonal transformation, so as to timely strike out all the redundant information in quantity. The simulation analysis shows that compared to classic stepwise regression this new method has a higher arithmetic speed and the modeling process is briefer and more efficient, when the variables appear in a large quantity and have a pretty serious server multicollinearity at the same time.
Integrated navigation algorithm for low-cost navigator in the primary trainer
Liang Haibo, Li Hao, Si Wenjie, LÜ Zhanggang
2013, 39(9): 1263-1268.
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To solve the invalidation of integrated navigation algorithm due to low updating frequency of global positioning system (GPS) in the low-cost integrated navigation system, a new integrated navigation algorithm, based on modeling of the inertial devices and kinematic modeling of the carrier, was presented. In this algorithm, the nonlinear system model was established. The attitude, velocity and position of the carrier were chosen to be the system state, and the output of the GPS, gauss meter, and altimeter were determined as the system measurement. The Kalman filter was adopted for data fusion after linearization of the system model. The static test and field test were implemented to validate whether the algorithm was useful. The test results show that the algorithm can effectively ensure that the error mean of attitude is smaller than 0.12 degree, the error mean of velocity is not larger than 0.03 meters per second, and the error mean of position is not larger than 3.94 meters, which is satisfied the requirement of the primary trainer.
Structural analysis of giant magnetostrictive actuator
Li Lin, Chen Liangliang, Yang Yong
2013, 39(9): 1269-1274.
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The structure form of giant magnetostrictive actuator(GMA) was studied in both mechanics and magnetics to obtain the properties of GMA. The patterns of permanent magnet (to induce the bias-magnetic-field), materials of the actuator-s covering and their impact on stroke and stiffness of the GMA were studied. The results show that the ring-type magnet leads to magnetic flux leakage, while the segment-type magnet with the steel covering can eliminate this phenomenon. Meanwhile the difference between the ideal and the actual bias magnetic field around the mandrel would greatly reduce the GMA-s stroke and has an assignable effect on the GMA-s stiffness. Both the stroke and the stiffness of the GMA must be considered in design. A novel design concept of the coupling magnetism and stiffness based on the properties of magnetostrictive material was proposed. The concept can provide a reference for structural design of GMA.
Effect of spraying power on microstructure and property of nanostructured thermal barrier coatings
Sun Youbei, Zhou Chungen
2013, 39(9): 1275-1278.
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Effect of air plasma spraying power on microstructure and thermal shock of nanostructured yttria stabilized zirconia (YSZ) thermal barrier coatings was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that there were two regions of melted phases and non-molten phases for the ceramic top coating under different power, non-molten phases included the nanosized grains, and phase composition was metastable tetragonal zirconia. With the increase in power, the area of nanosized grains gradually decreased, the porosity of the coating gradually reduced, and the life of the coating increased first and then decreased. The coating failure position was located at the ceramic top coating close to thermally grown oxide(TGO).

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