The ionosphere is the most complex factor of GNSS error of the civil aviation operation. As the character of complex model,disturbance,scintillation and storm,the ionosphere will bring serious effect to civil aviation especially at the solar cycles. Now there are the methods of model,relative positioning,and ICAO also start the work of collecting ionosphere data and creating regional ionosphere model. This paper is mainly focus on the ionosphere character,the effect of civil aviation,and bring forward the way to eliminate the ionosphere effect.
Ground-based area navigation is an important part of the implementation of area navigation,and the operation of ground-based area navigation must evaluate the coverage and accuracy of the DME facilities,in this way to ensuring the effectiveness and safety. This article describes the basic calculation principle of the ground-based area navigation system,the network structure,the system design method and the function of system,such as data management,analysis and evaluation of navigation performance,data exchange,and so on. This paper also introduces an application case which combined the specific airport. The purpose of this paper is that giveing a solution to solve the problem of ground-based regional navigation performance assessment.
The paper assessed GBAS accuracy performance based on two methods. A GBAS prototype was developed and used to collect and process GPS data. Based on the raw data,two methods called CMC and B values were used to analysis to GBAS accuracy performance. The result of both methods showed consistently that the GBAS prototype accuracy was on the level of GAD -A2 class. Compared with each other,CMC needs to use observations of dual frequencies,however,B values rely on single frequency. Secondly,CMC suppressed short-term multipath errors,and long-term multipath effects remained. B values,however,mainly consist of composite effects of multiple receivers忆errors after averaging across reference receivers,which reflect realistic errors of GBAS corrections as both occupied similar processes. Lastly,sky-maps of root mean squares of CMC and B values reflected surrounding multipath effects of GBAS sites.
According to the requirements on photorealistic 3D model of airside area in an airport,a parameter modeling method based on AMDB and OpenFlight API is proposed. Firstly,AMDB framework and data organization are analyzed. Secondly,according to the AIXM5 standards, the integrated geometric data interface for extracting AMDB data is designed. Thirdly,the feature classification model of airside area in an airport is proposed;furthermore,by using OpenFlight API,we generate the photorealistic 3D model in accordance with the classification. Finally,we construct some airport 3D model with the above method. This technology can be used to constructor the airport 3D model automatically according to different seasons and weather condition.
A complete set of symbols is not formed for VFR chart in our country for the slow development of general aviation. On the basis of the VFR chart collected from lots of designers,evaluation index of VFR chart was defined with the Cognitive semiotics and the demand of chart for VFR. All the sample data of the evaluation index was get through the visual perception test. Finally,the value of comprehensive evaluation was given by Fuzzy evaluation. The designing principal of VFR chart symbols was summarized. It provided the theory basis for the development of VFR chart.
Model along track kinematics equation of the aircraft by referencing to a classical conclusion that the along track error of the aircraft is normal distributed,consider an encounter between two aircrafts at the same flight level,construct an ellipse conflict region. By establishing a Caresian coordinates represented aircraft position appropriately. First,propose a probability estimation algorithm of medium term conflict detection for cross routes at the same level,then analyze the relationship between the conflict probability and several factors based on various graphs. The results show that when applying the algorithm to the conflict detection whose look ahead time is 15 minutes to 20 minutes,it can achieve perfect effects;under the same condition,the greater the angle between two routes is,the more precise the detection is. Meanwhile,compared with traditional randomized algorithm,the proposed algorithm is advanced in its simple calculation method,fast calculation speed and precise detection calculations. Finally,it could also be applied to the conflict detection of multi-segment,making it is much more widely used in medium conflict detection.
To take more advantage of the free space on the final pattern with ensuring the safety operation of arrival traffic,based on the objective analysis to the complexity drawing,the feature of the complexity map is summarized. A method of searching the free space on final pattern is constructed with the feature of complexity drawing. A method on maneuvering the arrival flights is suggested to provide the new idea for the simple and direct aid for control decision.
In order to describe the complexity of airspace sector in quantitatively,we introduced intrinsic concept of the transport,through the calculation approximation time,aggressive function,relation matrix,correlation function of the aircraft sector,then established the sector complexity measure model;and through simulation example,analyzed influence factors of complexity in the sector. Research results show that: the complexity value reflects the sector aircraft number and dispersion or convergence degree,complexity value curve inflexion number reflects the sector transportation ordered/disordered degree,complexity value curve mutations reflect the sector traffic number changes,at last providing certain support for ATC surveillance and conflict resolution options.
The purpose of this paper is to study the reduced thrust takeoff impact on the environment,including noise emissions and the impact of carbon dioxide and nitrogen oxides emissions of air pollutants. This study uses the method of controlled trials. We set different types of civil aircraft in the control group,and then analysis the results of the controlled trials to analyze the reduced thrust takeoff impact on the environment. It can be drawn by analyzing that the reduced thrust takeoff caused the close noise increased slightly and together bring a fall to the emissions of NOX ,but it nearly have no impact on CO2 emissions.
As an important part of Maintenance Review Board Report,the aircraft zonal inspection interval determined by zonal analysis,has great significance for aircraft safe operation. Given the present condition that there are still some nonstandard indexes and imperfections in the zonal rating system,an improved method is proposed in this paper after doing research on international main aircrafts. Firstly,the aircraft zonal influence factors are analyzed and specific rating indexes are established,after which the weight of each index and total ratings are determined by using analytic hierarchy process (AHP)and fuzzy theory. Secondly,ultimate maintenance intervals are obtained by the correspondence of rating and maintenance interval. Finally,this method proves feasible and effective through an example of the thrust reverser cowling.
To solve the problem of resource scheduling and management in the airports,Petri Net which is good at handling the real time processing of concurrent events is very suitable. CPN Tools is a simulation analysis tool of Petri Net which provides users with many tools for automatic analysis,therefore it is more easily and efficiently to model,simulate and analyze a given system. Hence,the model of turnaround flights using the main resources (such as the runways,gate positions,etc.)in the airport is proposed by using Colored- Timed Petri Net on the CPN Tools in this paper. And then we set some monitors to collect data during simulation. At last,we analyze these collected data,the simulation report and the state space report produced automatically by CPN Tools. From that we conclude the usage of main airport resources.
This thesis first introduces the operating policy for plateau in Chinese aviation area,proposing the basic scheme and the master layout of operating control. Then the special terrain and the fundamental situation of both Chengdu Shuangliu Airport and Lhasa Airport would be introduced. This thesis analyzes the particularity of operating control on plateau route,which is from Chengdu to Lhasa,and lays special stress on analyzing the drift-down program and the related question on route. Considering to the route from Chengdu to Lhasa,this thesis takes aircraft A319-115 as reference. It analyzes the drift-down problem and cabin decompression when one engine is failure. The limiting factors in actual operation are considered as the variable. The purpose of the analysis is to make a further development on the flight safety.
Through the systematic research of all kinds of the airport asphalt concrete runway damages,the model and methodology are established to calculate the safety risk index. Based on a great quantity of field comparison and correlation analysis,the safety risk rating scales (A,B,C,D)and the corresponding measures (suspended repair,repair between flights,post-flight maintenance,scheduled maintenance) are put forward. Finally,the application demonstrates the effectiveness of the methodology.
In this article finite element software is applied in analysis of the influence of aircraft load,surface layer thickness,flexural modulus of concrete and the rebound modulus of subgrade parameters on subgrade service depth with the additional stress is equal to the gravity stress of 10% as a standard. The results show that:the influence of aircraft load type on the service depth is relatively distinct,service depth in subgrade of light aircraft is about 1.5 m,and service depth of heavy aircraft reaches 6.0 m. The service depth in subgrade with the heavy aircraft ranged from 4.4~6.0 m under the condition of slab thickness in 0.2~0.5 m range,which extended by 36.4% of the lower value;the surface layer material flexural modulus to influence depth is very small. The service depth in subgrade with the heavy aircraft ranged from 4.4 m to 5.4m under the condition of the subgrade resilient modulus in 18~80 MPa range,extended by 36.4%. The conclusion above is more referenced by soft foundation treatment and analysis.
Tail assignment is the basic work in the airline manufacturing operations process,but it directly impacts the costs of the airline operating and the safety of flight. In this article,firstly,we found the integer programming model of flight-loop construction aiming to maximum the maintenance opportunity and made use of the combination of the column generation and Floyd shortest path algorithm to generate the flight-loop of multimaintenance base. Secondly,we used program by Matlab of branch-and-bound to obtain 0-1 optimal solution of programming model. Then,adopted the KM algorithm to complete the perfect match of the aircraft and flight-loop and realized the dynamic allocation of the flight-loop. Finally,through analyse of an instance we validated the correctness and efficiency of the method.
In order to study the temperature field distribution of the Carbon Fiber Reinforced Polymer(CFRP)material, the relation of temperature and direct current have been investigated on electric-thermal damage detection system. ABAQUS software is used to simulate the direct electrification process of CFRP based on current heating theory,and the temperature field distribution contour plot and temperature changes curves of characteristic points under different currents are obtained. By contrast of the experimental and stimulant results, fine consistency is reached.Surface temperature increase linearly with the current increase from 4A to 6A and 8A and reach stabilization after 160 s while the temperature is 162 ℃、177 ℃and 195 ℃ respectively. It shows that the detection system and simulation models could correctly predict the temperature field of current heating disposing and provide theory evidence for selecting current heating disposing parameters reasonably.
In this paper,the three degree barinder based on PMAC is studied,a new trajectory planning method is proposed according to the machining target,the trajectory planning of the original moving parts is achieved through the reverse simulation. Finally,a simple error analysis is created based on the kinematics simulation,and the feasibility of this method is explained by the simulation result and the error analysis.
The development of finger-vein recognition technology creates the need of the multispectral finger-vein image acquisition. In multispectral finger-vein image acquisition system,the near infrared (NIR)light control circuit and the spatial structure of NIR light source are two important hardware parts for obtaining proper luminance energy. In this paper,we propose a new strategy to improve our previous multispectral finger-vein imaging system. Firstly,the NIR light control circuit is redesigned considering the convenience of interaction between the NIR light control chip and the computer. Then,in order to approximately obtain a line NIR light source,the spatial structure of the NIR light is redesigned. Based on these two improvements,a new imaging device is made for capturing multispectral finger-vein images. The experimental results show that the proposed imaging system is effective and reliable for multispectral finger-vein image acquisition with high quality.
Wavelet function is introduced into hybrid stress element. The scaling functions of BSWI are used to construct the rectangular and cubic wavelet element as interpolation function. The results obtained in this paper are compared with those by Abaqus. The numerical examples illustrate that the wavelet-based element method has higher accuracy and higher accuracy，while it's less sensitive to the density of elements.
With the development of aviation industry and the improvement of people's living level,an increasing number of people prefer to travel on air. But the airline companies are using revenue management system for real-time price adjustment which keep fare changing significantly. The price is characterized by large floating,which makes it valuable practically to research on predicting price. A flight ticket fare prediction model based on time-serial is proposed in this paper. A prediction of ticket time-serial algorithm is designed and implemented. Comparative analysis of the predicted and actual travel sites published price has indicated that the model can provide more reliable for passengers booking decision support.
The development of general aviation leasing will meet the financing needs in the development of general aviation,improve the market environment of China's general aviation manufacturing industry,and spur the development of general aviation and its related industries. In this paper,analyze the main problems of China's general aviation leasing from internal and external reasons according to the business processes of general aviation leasing. The study propose the policy suggestions of the general aviation leasing development in order to improve the development of China's general aviation leasing.
