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Journal of Civil Aviation University of China 2020 Vol.38 Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Realization of dual-frequency localizer horizontal radiation characteristics#br# NI Yude, WANG Ning, FAN Yi Journal of Civil Aviation University of China    2020, 38 (1): 1-6.   Abstract （1810）            Knowledge map    Save ILS provides precision approach service for civil aviation. The horizontal radiation characteristics of LOC that provides horizontal guidance information directly affects the navigation performance of ILS. Using 3D electromagnetic simulation software FEKO, an LPDA composed of seven symmetric oscillators which is widely used in LOC, is designed. Combined with dual-frequency LOC feeding mode, the radiation pattern of dual-frequency 12-cell LOC is realized through simulation. Results show that the designed LPDA basically meets the HPBW requirements of LOC array element, and the horizontal radiation characteristics of LOC array antenna meet the coverage requirements of the relevant standards of ICAO. Reference | Related Articles | Metrics | Comments（0） Select Design and implementation of self-adaptive ADS-B anti-interference receiver monitoring software#br# WU Renbiao, ZHANG Lulu, HU Tieqiao Journal of Civil Aviation University of China    2020, 38 (1): 7-12.   Abstract （1605）            Knowledge map    Save The increasingly complex space electromagnetic environment makes ADS-B system facing various interference problems. Most current ADS-B receivers in and abroad do not have the capability of autonomous anti-interference. A real-time receiver monitoring software is designed according to the special requirements of ADS-B self-adaptive anti-interference receiver for monitoring system, including software system composition, key unit design and performance test. Results show that the proposed software can quickly and accurately transmit receiving data,working status, control commands and other information, and generate a visual interface, providing reference for the development of ADS-B anti-interference receiver monitoring system. Reference | Related Articles | Metrics | Comments（0） Select Numerical simulation on aero-engine turbine rim sealing#br# TAO Liquan, MA Zhen, QIU Xuewang Journal of Civil Aviation University of China    2020, 38 (1): 13-18.   Abstract （1763）            Knowledge map    Save Aero-engine turbine rim sealing is vital for rotor-stator system protection. In order to avoid main flow high temperature gas ingesting into rotor-stator system, it is necessary to induce low temperature gas inflow to rotorstator system. 2D RANS model and SST turbulence model are used to study the effect of different sealing flow on sealing efficiency, the minimum sealing flow is determined by pressure parameter method, the influence of different seal heights on sealing efficiency is studied. Results show that with the increase of sealing flow, the turbine flange is gradually sealed and the sealing efficiency of turbine rim increases. At the same time, the outflow of sealing gas from turbine cavity into mainstream results in the increase of mainstream pressure, which makes the sealing gas has a certain influence on the main stream. Because the sealing gas is filled with disk cavity, it is difficult for the high-temperature mainstream gas to enter the disk cavity, and the heat exchange between mainstream gas and sealing gas occurs in the entrance area of layer seal, which makes great change of temperature, mainstream gas and improves the sealing efficiency; meanwhile, experimental results show that different sealing layer heights has no effect on sealing efficiency. Reference | Related Articles | Metrics | Comments（0） Select Aero-engine baseline mining based on chaotic PSO_Elman network#br# QU Hongchun, LIN Wenbin, XU Wangshan, GUO Longfei Journal of Civil Aviation University of China    2020, 38 (1): 19-23.   Abstract （1642）            Knowledge map    Save In order to improve the fitting precision of engine baseline, an Elman neural network model optimized by chaotic particle swarm is proposed. The position formula of PSO is improved by chaos algorithm to solve the local optimization problem. A nonlinear decreasing function is proposed to improve the PSO particle velocity formula to solve the problem of low convergence accuracy. The model is applied in baseline fitting and the fitting errors are compared with those of traditional BP network, Elman network and SVM. Results show that the fitting accuracy of chaotic PSO_Elman model is higher than that of other traditional models with the same training and testing data and the same training times. When the training samples get fewer, the fitting accuracy is still higher than the traditional models, proving the stronger learning ability of the model. Reference | Related Articles | Metrics | Comments（0） Select Task packeting optimization model of civil aircraft planned maintenance#br# ZHANG Peng, FU Jie, ZHAO Shiwei Journal of Civil Aviation University of China    2020, 38 (1): 24-28.   Abstract （2053）            Knowledge map    Save The continuous expansion of domestic airline fleets has led to the rapid growth of maintenance workload. The manual packeting of maintenance task is commonly unreasonable and inefficient. Through analyses on maintenance task attributes and interval parameter conversion rules, the man hours and the parking time of aircraft to finish the maintenance task package are taken as constraints, and the maximizing accumulative total time of executing all maintenance task packages during post-flight parking is taken as objective function. A model for civil aircraft maintenance task packeting optimization is established. According to the interval deviation regulations from AC-121-53, an algorithm is constructed to solve the model. Simulating verification is conducted taking B737NG as instance. Results show that maintenance task package which meets both the required maintenance capability and the post-flight parking time can be obtained via this model, balancing the manpower demand, improving the aircraft utilization and reducing the maintenance cost. Reference | Related Articles | Metrics | Comments（0） Select Influential factor analyses of aircraft cabin thermal comfort#br# JI Yuchu, LI Ze Journal of Civil Aviation University of China    2020, 38 (1): 29-33.   Abstract （2131）            Knowledge map    Save Cabin thermal comfort may decrease because of unreasonable operation of ground air conditioner during ground working, therefore the cabin environmental factors which may influence passenger爷s comfort should be comprehensively evaluated. According to the characteristics of cabin environment, PMV is selected as thermal comfort evaluation index. Employing simplified PMV model, the influence of cabin environmental factors (temperature,humidity, air flow speed) on PMV index is analyzed. Results show that cabin temperature has the greatest impact on cabin thermal comfort, air flow speed is the second factor, and humidity has least impact. Cabin thermal environment control based on PMV is more efficient and energy-saving than traditional way (constant and fixed cold/hot air supply). Reference | Related Articles | Metrics | Comments（0） Select Triangular mesh method of RTK height fitting based on external coincidence accuracy#br# JIAO Weidong, ZENG Lanfeng Journal of Civil Aviation University of China    2020, 38 (1): 34-37.   Abstract （2019）            Knowledge map    Save RTK height fitting method based on DT mesh can not obviously improve the external coincidence accuracy in the case of fewer fitting points. Two methods to improve the external coincidence accuracy of triangular mesh are proposed. In the first method, the minimum external coincidence accuracy is regarded as the limit criterion for triangular mesh connection without consideration about the characteristics of DT mesh. In the second method,both detection points and fitting points are used to generate a DT mesh which makes the external coincidence accuracy achieving the optimal value. Results show that these two methods can effectively improve the fitting accuracy of triangular meshes, and can meet the fourth-class leveling standard of engineering survey application. Reference | Related Articles | Metrics | Comments（0） Select Constrained random coding method for high-intensity distribution of image texture#br# GAO Qingji, PENG Chuanbo, FANG Rong Journal of Civil Aviation University of China    2020, 38 (1): 38-42.   Abstract （1506）            Knowledge map    Save Aiming at the difficulties during stereo matching of weak-texture-object in binocular stereo vision system, a constrained random coding image generation algorithm is proposed for enhancement of texture quality. Firstly,according to the search strategy of stereo matching algorithm and calculation method of cost aggregation, the pixel coding rules of the projected image are designed, and the calculation method under local uniqueness constraint of projection and target hybrid image position pixels is established to form a high-intensity texture distribution image. The constrained random coded image generated by the algorithm is projected onto the surface of air baggage, the 3D reconstruction of air baggage surface is performed by stereo matching algorithm, and the reconstruction result is evaluated. The reconstruction experimental results of standard parts and actual baggage show that the proposed algorithm can accurately and reliably model the air baggage with solid color or weak texture features. Reference | Related Articles | Metrics | Comments（0） Select Seismic signal separation method based on EWT#br# FEI Chunguo, DOU Jiachen, WANG Yang, JI Yuchu Journal of Civil Aviation University of China    2020, 38 (1): 43-48.   Abstract （1516）            Knowledge map    Save Seismic signals generated by ground target movement can be used for target location and recognition. When there exist multiple types of ground targets, the signal aliasing phenomenon may interfere signal analysis. EWT algorithm divides the spectrum into several segments according to its maxima value, and transform the signals by constructing orthogonal wavelet functions in each segment to obtain multiple empirical mode signals. However, if the segments are merely devided according to the maxima value, dense peaks may result in too many modes. To solve this problem, spectrum envelope is extracted repeatedly to reduce the number of peaks, and then spectral threshold segmentation algorithm is proposed to enhance discrimination among different signals. Experiments show that improved EWT algorithm has better separation effect for seismic signals from different targets. Reference | Related Articles | Metrics | Comments（0） Select Temperature field boundary layer parameters ofpermafrost subgrade in Mohe district#br# QI Chunxiang, LI Yao, MA Lin, DONG Bin Journal of Civil Aviation University of China    2020, 38 (1): 49-53.   Abstract （1715）            Knowledge map    Save Integrating the second and third upper boundary conditions, permafrost subgrade temperature field distribution of airfield runway in Mohe district is simulated by using ABAQUS, the application of boundary layer theory in Mohe district is discussed, the boundary layer parameters and temperature function of permafrost subgrade temperature field in Mohe district are studied. Result shows that the boundary layer thickness of asphalt concrete runway pavement in Mohe district is 0.12 m, initial value of subgrade temperature at the bottom of boundary layer is 1.90 ℃and the amplitude is 25.09 ℃; Thickness of boundary layer of natural ground is 0.06 m, initial value of subgrade temperature at the bottom of boundary layer is 1.03 ℃and the amplitude is 25.20 ℃. Finally, the applying districts of boundary layer theory is expanded, providing research basis for of airfield runway subgrade stability in Mohe district. Reference | Related Articles | Metrics | Comments（0） Select Synchronous acquiring system design of multimodal finger image#br# YANG Jingfeng, LI Changfu Journal of Civil Aviation University of China    2020, 38 (1): 54-59.   Abstract （1553）            Knowledge map    Save In the fusion of multimodal finger identification, pose synchronization of three-modal finger images including finger vein, finger-knuckle-print and finger print is crucial for recognition performance improvement. Firstly, a new hardware imaging mode is adopted to make consistent imaging pose of multimodal finger traits. Secondly, random plane-rotation of finger pose is corrected through finger posture angle calculation to reduce finger imaging posture change using algorithm. Finally, ROI coordination of finger vein and finger-knuckle-print is conducted by image space mapping. Experimental results prove the stable performance of the proposed image acquisition scheme, which basically resolves the finger pose variation. Reference | Related Articles | Metrics | Comments（0） Select Multi-particle erosion mechanism of elastic coating based on cohesive element#br# XU Jianxin, ZHU Xiahong, GUO Qiaorong, LI Dinghe Journal of Civil Aviation University of China    2020, 38 (1): 60-64.   Abstract （1403）            Knowledge map    Save A multi-particle erosion model of elastic coating is established based on cohesive elements, the stress distribution on coating and bonding layer with erosion caused pit damage is analyzed. The influence of erosion density, particle distance and erosion times on stress distribution on coating and bonding layer are discussed. Results show that: with the same pit depth, the maximum values of radial contact stress and shear stress of bonding layer locate at the contact edge. The bigger erosion density of particles is, the smaller the maximum tensile stress of the coating becomes, the less likely it is to crack. The maximum radial stress on coating locates at the contact edge of the outermost particles. There is no interaction between particles when the distance between circle centers is bigger than the sum of their diameters. The locations of crack and delamination get closer to the contact edge when the stress produced by repeated erosion is smaller than single erosion. Reference | Related Articles | Metrics | Comments（0） Select Path planning method for UAV cascaded relay communication LIU Haitao, FANG Xiaoyu, GU Xinyu, LI Dongxia Journal of Civil Aviation University of China    2020, 38 (2): 1-6.   Abstract （2110）            Knowledge map    Save UAV cascaded relay communication is an important technical scheme for the long-distance point-to-point wireless communication. Aiming at UAV path planning problem in UAV cascaded relay communication system with a mobile user node, a joint optimization and a stepwise optimization path planning method are proposed based on the maximization of ergodic capacity criterion. And the outage probability of the UAV cascaded relay communication system is derived by using FM-EM algorithm. Simulation results demonstrate the accuracy of the proposed path planning methods. Research indicates that the stepwise optimization path planning method achieves the same performance as the joint optimization path planning method. Reference | Related Articles | Metrics | Comments（0） Select Lean and sweep optimization for aero-engine fan blades and aerodynamic characteristics analyses BAI Jie, XIONG Peng, SHI Lei Journal of Civil Aviation University of China    2020, 38 (2): 7-12.   Abstract （2413）            Knowledge map    Save The lean and sweep on the fan rotor of one aero-engine is optimized based on numerical model to improve the total pressure ratio and isentropic efficiency and ameliorate the overall performance of the engine under design conditions. Steady numerical simulation is implemented to analyze the grid independence and verify the effectiveness of the model employing 800 000 gridding plan of fan rotor. The stacking line is fitted by Bezier curve, controlling its lean and sweep with parameters; Taking total pressure ratio and isentropic efficiency at the design point as objective functions, automatic optimization is completed using artificial neural network and genetic algorithm. Comparing with the original model, the total pressure ratio and isentropic efficiency have been increased respectively by 0.18% and 0.71%. The static pressure distribution along the span and chord direction are adjusted, reducing the tip loss and end wall loss and improving the fan aerodynamic performance at the design point. Reference | Related Articles | Metrics | Comments（0） Select Aeroengine residual life prediction based on time series similarity CAO Huiling, LIANG Jiawang Journal of Civil Aviation University of China    2020, 38 (2): 13-17.   Abstract （1971）            Knowledge map    Save Performance degradation is one of the main reasons leading to the aeroengineremoval. Aiming atthe huge difference between individual performance degradation modes of the same type of aeroengine, the engine residual life prediction method based on similarity matching is proposed. Firstly, EGTM is selected to characterize the current performance state of the engine, similar correction and Dixon outliers are used to eliminate the influence of external factors. Secondly, K-means is conducted to the EGTM data. Finally,Euclidean distance method is used to calculate the similarity degree between predicted and historical samples,giving corresponding weight of the reference samples to predict the residual life of the engine. The actual data verification of airlines, shows that the proposed method has high prediction accuracy and can provide reliable basis for maintenance plan. Reference | Related Articles | Metrics | Comments（0） Select Access control method based on CP-ABE in NDN WU Zhijun, XU Enzhong Journal of Civil Aviation University of China    2020, 38 (2): 18-24.   Abstract （1479）            Knowledge map    Save Information caching technology in NDN improves data distribution efficiency. However, information caching decouples data publishers from data. The data in the storage node is at risk due to lack of security controls.Therefore, an access control method based on CP-ABE is proposed in NDN, which combines the improved CPABE algorithm with symmetric encryption, and introduces a re-encryption module in the edge router for protected data access coordination and privilege revocation. At the same time, a hash table-based interest packet filtering mechanism is built, implementing fine-grained access control and privilege revocation on a semi-trusted cache router. Theoretical analysis and experimental simulation results show that the proposed method reduces the overhead of data publishing and data request processing and improves data access efficiency. Reference | Related Articles | Metrics | Comments（0） Select Identification method of accelerometer error parameter based on IMU WANG Li, XI Xianqiang Journal of Civil Aviation University of China    2020, 38 (2): 24-27.   Abstract （1856）            Knowledge map    Save As the core component of IMU, the accelerometer accuracy directly affects the IMU accuracy. In order to improve the output performance of accelerometer, a 24-position method is proposed to identify the accelerometer error parameters. Firstly, the accelerometer output error model is established according to the input and output formula of accelerometer. Then the accelerometer error model parameters are identified by 24-position method and the calibration process of which is designed in details giving the calculation method of scale factor, misalignment angle and zero offset of the accelerometer. Finally, position test is performed by turntable to collect data and to conduct calculation as well as data analyses. Experimental results show that the proposed method can quickly identify the accelerometer error parameters and establish an accurate accelerometer error model. Reference | Related Articles | Metrics | Comments（0） Select Aircraft ground AC system simulation based on PSO-BA algorithm DING Fang, ZHOU Yang, WU Tingna, CHEN Guibo Journal of Civil Aviation University of China    2020, 38 (2): 28-32.   Abstract （1496）            Knowledge map    Save Due to the variable working conditions, large amount of parameters and huge delay of aircraft ground AC system, the traditional PID control has been unable to meet the requirement of high efficiency and speed in practition, Bat algorithm is introduced to optimize the partical swarm algorithm and improves the traditional PID control in aircraft ground AC system. Simulation result shows that the improved PSO algorithm has strong robustness and can effectively suppress the huge delay and other problems, which provides a theoretical reference for the improvement of aircraft ground AC system. Reference | Related Articles | Metrics | Comments（0） Select Load balance control strategy under smart apron grid structure FEI Chunguo, MENG Meihan Journal of Civil Aviation University of China    2020, 38 (2): 33-37.   Abstract （1635）            Knowledge map    Save Driven by flight flow, there appear problems such as large number of scattered nodes, strong heterogeneity of data, and dynamic changes of network topology in civil aviation apron network, resulting in load unbalance, fast resource consumption and short network life. Based on the theory of grid structure, an optimized ant colony algorithm for load balance control of apron router is proposed. The heuristic factor is defined by load quantity; negatively correlated transformation is conducted to the pheromone parameter of transition probability in order to realize load balancing of path transmission. Meanwhile, the network topology is optimized by deploying network node density. Simulation results show that the routing algorithm based on ant colony optimization is superior to the original LEACH algorithm in network energy consumption balancing, data transmission rate improvement and network life cycle increasing. Reference | Related Articles | Metrics | Comments（0） Select Simulation analysis on influence of groove abrasion on aircraft hydroplaning CAI Jing, XU Zheng Journal of Civil Aviation University of China    2020, 38 (2): 38-43.   Abstract （1727）            Knowledge map    Save The abrasion condition of aircraft tires has big influence on its hydroplaning behavior, and then affects flight safety. Aiming at this problem, the tire models with different abrasion degrees are established by using finite element software, and CEL algorithm is used to establish tire—waterfilm—pavement interaction model. The influence of tire abrasion degree on the three factors‘interaction is analyzed, and the critical hydroplaning speed of tires with different abrasion degrees on pavement with various waterfilm thickness is calculated. Results show that when the groove abrasion degree is more than 50% , the drainage capacity decreases obviously, and the distribution of hydrodynamic pressure on the front edge changes. With the increase of tire abrasion degree, the critical hydroplaning speed will decrease continuously. When the groove depth gets abraded to less than the current waterfilm thickness, the critical hydroplaning speed of the tire decreases by 16%~20%, hydroplaning is more likely to occur, which will affect the maneuverability of aircraft during landing. Accordingly, airliners are suggested to revise the tire replacement standard to ‘replace the tire when the abrasion rate reaches 50%’. Reference | Related Articles | Metrics | Comments（0） Select Visualized airline competitiveness evaluation based on decision ball model LONG Hanliang, CHEN Ye, XU Haiyan Journal of Civil Aviation University of China    2020, 38 (2): 44-50.   Abstract （1487）            Knowledge map    Save Improving the competitiveness of airlines is the key to build a strong civil aviation country. A competitive evaluation index system is built considering the scale strength, operational capability, service quality and profitability. Decision ball model is applied to conduct dynamic data analyses and visualization for major airlines of the world from 2008 to 2017. Empirical analysis of airlines爷competitiveness shows that service quality and profitability are typical shortcomings of Chinese airlines. Suggestions about competitiveness promotion are supplied basing on analyses of advanced samples. Reference | Related Articles | Metrics | Comments（0） Select Safety recommendation comparison of aviation accident investigation reports between China and US based on WFA CUI Zhenxin, SUN Wenlong Journal of Civil Aviation University of China    2020, 38 (2): 51-54.   Abstract （2168）            Knowledge map    Save After an aviation accident/incident happens, the accident investigation agencies will propose corresponding safety recommendation for the hidden dangers of aviation system found during investigation. WFA is conducted aiming at the key words of safety recommendation in the Sino-US aviation accident investigation reports, including 130 accident investigation reports issued by CAAC in 2017 and 53 accident investigation reports released by US NTSB in 2013-2017. Results show that the four aspects of safety recommendation mostly involved are ‘pilot/unit’,‘procedure/regulation’‘machine/equipment’‘practice/training’, which are the key orientations of aviation safety management. Most safety recommendation given by CAAC aims at airlines, while the US aims more at FAA; in terms of procedure and regulation, CAAC emphasizes mostly the compliance of regulation, while the US emphasizes the revision of regulation. Reference | Related Articles | Metrics | Comments（0） Select Comparative study on aircraft type certification system documents between China and US LI Jing, GE Hongjuan, LIANG Zhouchi, DONG Xiaoxu, JIE Yuwen, QU Zhanwen Journal of Civil Aviation University of China    2020, 38 (2): 55-59.   Abstract （1704）            Knowledge map    Save Aircraft type certification documents under different organizations both in China and US are analysed, including airworthiness regulations, orders, airworthiness management procedures and advisory circulars. Differences and revision analysis of airworthiness regulations of China and US are compared by taking CCAR-25 and FAR-25 as examples, basing on that, suggestions to supplement CAAC advisory circular and improve airworthiness management procedures are proposed from aspects of the specific content of documents, designee management document framework, designee type document and so on, providing reference for document system improvement of aircraft type certification for CAAC. Reference | Related Articles | Metrics | Comments（0） Select Flexural properties of repaired composite laminate structure under hygrothermal conditions SU Jingxin, ZHAO Wenhao, CHEN Dong, LU Pengcheng Journal of Civil Aviation University of China    2020, 38 (2): 60-64.   Abstract （1430）            Knowledge map    Save In order to research the evolves regularities and mechanism of bending properties of composite repaired structures for civil aircraft structures when dealing with environmental changes, the bending behavior and failure mechanism of benzoxazine composite laminates under dry/hygroscopic conditions are systematically researched by means of electronic universal material testing machine, scanning electron microscope and laser confocal microscope. Results show that the bending strength of the bulk material/autoclave, bulk material/thermal compensation instrument, non-bulk material/autoclave,non-bulk material/thermal compensation instrument repair test plate can be restored to 99%,95%,97%,87% of the intact sample at room temperature. After heatmoisture treatment,the flexural properties restoration ratesare respectively reduced to 65%, 56%, 60%, 34%. Bending fracture analysis shows that the failure mode of the intact specimen is tensile fracture of the fiber,and the failure mode of the repaired specimen is tensile fracture and debonding pull-out of the fiber. In summary,the fiber/resin interface bonding of the repaired specimen has the best performance by usingthe bulk repair material/ hot-pressing pot curing method. Reference | Related Articles | Metrics | Comments（0） Select RF terminal design and implementation for self-adaptive ADS-B anti-interference receiver HU Tieqiao, LIU Liang Journal of Civil Aviation University of China    2020, 38 (3): 1-7.   Abstract （1546）            Knowledge map    Save Aiming at the special requirements of self-adaptive ADS-B anti-interference receiver, RF terminal with good channel consistency is designed involving design scheme, key component design and performance testing. Test results show that the current RF terminal has higher gain, lower noise ratio and better channel consistency,meeting the special requirements of self-adaptive ADS-B anti-interference receiver, and supplying reference for the independent research and development of which. Reference | Related Articles | Metrics | Comments（0） Select Multi-runway airport hot spot recognition method based on Monte Carlo simulation MENG Linghang, TIAN Chuan Journal of Civil Aviation University of China    2020, 38 (3): 8-11.   Abstract （1808）            Knowledge map    Save The runway and taxiway systems of large airports are becoming more and more complex. For the newly built airport, it is difficult to find the hot spots due to the lack of historical operational data. Aiming at the identification of taxiing hot spots in multi-runway airports, a fast identification method based on Monte Carlo simulation is proposed. Firstly, the ground network model of airport flight area is modeled using Dijskra algorithm to determine the set of Q shortest paths between any current node in the airport ground network and the runway entrance or parking area. Then, the traffic flow and aerodrome control rules are modeled, identifying the hot spots of multirunway airport via Monte Carlo simulation. Taking the double runway “West Takeoff and East Landing”,operation of Changsha Huanghua Airport as an example, the simulation result and published taxiing hotspots in AIP CAAC are compared, verifying the validity of the proposed approach. Reference | Related Articles | Metrics | Comments（0） Select Nonlinear steady state control of small turbofan engine based on LMI CAO Huiling, ZHENG Lijiu Journal of Civil Aviation University of China    2020, 38 (3): 12-17.   Abstract （1567）            Knowledge map    Save Aiming at the strong nonlinear characteristics of aero-engine, a general nonlinear term is introduced based on its linear state space model to broaden the working range of it. Based on the nonlinear model, a generalized Gronwall-Bellman lemma is applied to design a steady state controller. Then the performance of the controller is verified by applying the Lyapunov stability theorem. DGEN380 engine is taken as simulation object, and the above controller is simulated. Simulation results verify the effectiveness of the current method. Reference | Related Articles | Metrics | Comments（0） Select Rutting profile characteristics and evaluation indices under aircraft wheel load LI Yue, ZHAO Fupeng, CAI Jing Journal of Civil Aviation University of China    2020, 38 (3): 18-12.   Abstract （1638）            Knowledge map    Save Rutting profile characteristic obtained from ordinary rutting test can be quite different from the actual situation,which makes the rut depth indices insufficiently representative. Based on the CC5 test carried out by NAPTF, a 3D rutting analysis model of flexible pavement structure is established by using ABAQUS. A load curve of halfsine wave is adopted to simulate the cyclic load process of the moving aircraft gears. The feasibility and accuracy of the model are then verified and evaluation indices are proposed considering the complexity of rutting profile characteristics. The load position lateral shift of aircraft gears is well reproduced in the simulation, therefore a series of turning points appeared in the rutting curves. The rutting depth of such points were then extracted, and the average rut depth and standard deviation were obtained after processing. Analyzingresults indicate that the average rutting depth and standard deviation can be used to describe the full-section feature of rutting profile.The environment temperature has notable impact on the distribution and development of rutting deformation. The simulated average rutting depth under the condition of 50益can be higher than that of the CC5 the results by 40%, and the standard deviation was increases by 70%. Reference | Related Articles | Metrics | Comments（0） Select Thin layer repair material for airport pavement CHENG Guoyong, YANG Yiheng Journal of Civil Aviation University of China    2020, 38 (3): 23-27.   Abstract （1838）            Knowledge map    Save It is difficult to repair or achieve a satisfactory repair effect because of the non-stop flight regulation and cement concrete deformation characteristics under load. Epoxy resin (epoxy value is 0.44) and polyamide resin are used as curing agent. Glass layer, mica powder, alumina, titanium oxide are used as fillers of pavement surface thin layer repair materials. Performance indices of the four proportioning schemes are tested including BPN, impact resistance, wear resistance (TD value) and durability. Testing result shows that the BPN of the thin layer repair material under the designed proportioning is increased by 14%~27%, the impact resistance is increased by 140%~320%, TD values of all the four proportion schemes are more than 0.7, and all the loss rates of high temperature and freeze-thaw tests are less than 2%, the second proportioning scheme has the best comprehensive properties.The test result can provide technical reference for the proportion of airport pavement thin layer repair material. Reference | Related Articles | Metrics | Comments（0） Select Flight support Petri net construction based on Bayesian network structure learning XING Zhiwei, CHEN Zhe, XIA Huan, LUO Qian, CONG Wan, CHEN Fenghua Journal of Civil Aviation University of China    2020, 38 (3): 28-33.   Abstract （1502）            Knowledge map    Save Due to the limitation of airport resource and time window during peak hours, the actual process of flight support will be biased compared to the planned process. K2 algorithm of Bayesian network structure learning is employed into flight support working scenarios, proposing the Bayesian network structure learning model of flight support.Bayesian network and Petri net are combined to build a Bayesian acyclic Petri net in order to accurately describe the status alternation of aircraft during flight support procedures. Finally, the actual data of one domestic hub airport are used to construct flight support network structure. Experimental analyses show that the flight support network obtained from historical data can better fit the actual working flow. Reference | Related Articles | Metrics | Comments（0） Select International route network optimization for airline alliance under uncertain demand YANG Wendong, SHAO Jiajia, ZHENG Wenjuan Journal of Civil Aviation University of China    2020, 38 (3): 34-39.   Abstract （1526）            Knowledge map    Save Taking the collaboration network of alliance airlines as the research object, based on the three-subscript model of hub-and-spoke network, and in response to the uncertainty of passenger demand, a stochastic programming model for the international route network optimization for airline alliance is constructed. The relatively better consistent international gateways, as well as the transportation paths and flows that vary with different scenarios can be obtained. Two indicators are proposed to evaluate the improving extent of the solution obtained from stochastic program than the deterministic approaches. The superiority of the stochastic programming model is verified by example analysis, providing useful decision-making reference for the construction and optimization of international route network for airline alliance. Reference | Related Articles | Metrics | Comments（0） Select Design of price-based airfare search method ZHANG Honghai, PENG Mingtian, LIU Kaisheng Journal of Civil Aviation University of China    2020, 38 (3): 40-44.   Abstract （1424）            Knowledge map    Save Aiming at the complex airfare combination and huge search space in the current civil shipping price search method, a Price-based airfare heuristic search method is proposed. Heuristic search algorithm is used to estimate the price and comfort of potential trips through travel experience data, eliminate unreasonable combinations, and screen out the final results that meet the individual needs of passengers. By constructing the travel experience information database, the design of airfare index, freight route selection, airfare splitting and combination is optimized, and the solution space is reduced. The high-performance search of airfare combination has been realized,and the service quality of passengers‘ticket purchase has been improved. Reference | Related Articles | Metrics | Comments（0） Select Fault classification method for transmission line based on voltage amplitude and SVM FEI Chunguo, HUO Hongshuang Journal of Civil Aviation University of China    2020, 38 (3): 45-49.   Abstract （1514）            Knowledge map    Save In order to realize the fast and accurate classification of high voltage transmission line fault, a fault classification scheme is proposed based on fault voltage signal amplitude and SVM. The half-circle fault amplititudes of threephase voltage intercepted after filtering just are applied as fault features in the novel scheme, being input to SVM intelligent fault classification system. After training and predicting, the scheme can identify fault types on transmission line. According to system simulation results, the fault classification method can effectively improve the speed and the accuracy of fault classification, which is lightly affected by factors such as fault impedances,fault inception angles, fault location and so on. It has good adaptability and the accuracy of fault classification can reach 100%. Reference | Related Articles | Metrics | Comments（0） Select Kinematics simulation analysis on composite six-DOF platform DONG Tingjian, WU Qingyu, WANG Yanan Journal of Civil Aviation University of China    2020, 38 (3): 50-54.   Abstract （1595）            Knowledge map    Save Aiming at the disadvantages of the common six-DOF platform such as small motion space and large dimensional size, a composite six-DOF platform is designed. D-H parameter method is adopted to establish the platform linkage coordinate system, by which the basic equations and forward-inverse solutions of the platform kinematics are all obtained. SolidWorks is used to establish the 3D platform model, which is then imported into ADAMS for kinematics simulation and analysis. Simulation curves of displacement, velocity, angular velocity, acceleration and angular acceleration in x, y and z directions of the platform are analyzed, verifying the rationality of the platform structure design and providing theoretical basis for the optimization and strength check. Reference | Related Articles | Metrics | Comments（0） Select Restoration of finger vein image based on multiple scattering model YANG Jinfeng, ZHANG Xirui Journal of Civil Aviation University of China    2020, 38 (3): 55-60.   Abstract （1415）            Knowledge map    Save To improve the restoration quality of finger vein images and better describe the propagation characteristics of photons in skin tissue, a multiple scattering model is proposed by adopting GGD as convolution kernel to approximately describe the diffusion characteristics of photons during transmission and attenuation process in skin tissue. Then maximum filter and anisotropic diffusion filter are used to estimate the background lighting, and the transmission map is obtained by Laplacian sharpening and high lifting filter. MSSIM index is introduced to evaluate the quality of finger vein image restoration. Experiment results indicate that the proposed algorithm can effectively improve the restoration quality of finger vein images. Reference | Related Articles | Metrics | Comments（0） Select Dynamical analysis on stochastic three-specy model with impusive toxicant GAO Yongxin, WANG Nana Journal of Civil Aviation University of China    2020, 38 (3): 61-64.   Abstract （1290）            Knowledge map    Save A stochastic three-specy prey-predator model with Beddington-DeAngelis functional response and impusive toxicant input is studied in order to find out how white noise and impusive toxicant input influence the dynamics of the model. By analyzing the limit system of the proposed model, the sufficient conditions for extinction, mean strong persistence and superior bound with average time are supplied. Reference | Related Articles | Metrics | Comments（0） Select Flight tracking gap assessment based on multi-source heterogeneous data#br# HAN Ping, ZHANG Bingqing, ZHANG Zhe, LU Xiaoguang Journal of Civil Aviation University of China    2020, 38 (4): 1-6.   Abstract （1579）            Knowledge map    Save Aiming at the location report gap of ACARS or ADS-B during global flight tracking, a flight tracking gap assessment model is established based on the ACARS and ADS-B messages. Firstly, the model reconstructs the missing points by cubic spline interpolation algorithm, then divides the point coverage area and the missing area in the evaluation area. SVM algorithm based on Gaussian kernel function is used to obtain the tracking gap location probability distribution inside the missing area. Finally, test data are used to evaluate the model performance. Results show that the assessment model is suitable for two kinds of multi-source heterogeneous data, and the accuracy is higher with shorter data period. Reference | Related Articles | Metrics | Comments（0） Select GNSS spoofing detection algorithm based on composite SQM variance#br# WANG Wenyi, GONG Jing Journal of Civil Aviation University of China    2020, 38 (4): 7-12.   Abstract （2050）            Knowledge map    Save GNSS is vulnerable to spoofing and interference due to its open signal structure and weak signal power. SQM has been proved being able to detect spoofing attacks. However, due to the increasing variety of existing spoofing types, a single SQM algorithm in specific spoofing situations can no longer meet the need for real-time and high performance detection of spoofing attacks. A spoofing detection method is proposed to detect the change of composite SQM in the detection code tracking loop, which can detect the existence of spoofing based on the change of variance value of composite SQM and conduct experimental analysis with actual signals of TEXBAT. Experimental results show that this method can detect spoofing attacks in a short time without increasing the complexity of the algorithm with better performance than that of the composite SQM algorithm. Reference | Related Articles | Metrics | Comments（0） Select Applicability study of HF loop antenna in civil aircraft#br# CHEN Shihao, MENG Jian Journal of Civil Aviation University of China    2020, 38 (4): 13-16.   Abstract （1683）            Knowledge map    Save Considering the performance requirements and design constraints of civil aircraft communication system on HF antenna, key technical indicators such as impedance features, efficiency, power capacity, radiation features and gain of HF loop antenna are analyzed by simulation. Basing on the analyzing results, the installation requirements of loop antenna are porposed. It is proved that loop antenna has flexible design and could be the optimal type of civil aircraft HF antennae. Reference | Related Articles | Metrics | Comments（0） Select Engine performance analysis under static uneven tip clearance#br# CAO Huiling, WANG Han Journal of Civil Aviation University of China    2020, 38 (4): 17-20，36.   Abstract （1676）            Knowledge map    Save Turbine tip clearance has great influence on engine performance. Borescope inspect image shows that the friction between the leading edges of HPT blade and shroud is severe, and the engine performance keeps low. It is found that the leading and trailing edges of HPT produce uneven expansion deformation under hot state. HPT leading edge grinding angle is adjusted in CFM56 aero -engine under static condition to produce uneven clearance between leading and trailing edges of blade tip position and to carry out the test. 3D turbulence numerical simulation is used to simulate the flow field of HPT and calculate its efficiency as well as thermal efficiency of the whole engine under working state. The key performance parameters are analyzed and the influence of static uneven tip clearance on turbine efficiency and engine performance is studied in combination with maintenance and test data. Result shows that the uneven tip clearance maintenance scheme can reduce the friction of shroud and effectively improve the performance of high-pressure turbine components and the engine. Reference | Related Articles | Metrics | Comments（0）