Table of Content

01 December 2021, Volume 39 Issue 6

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Civil Aviation

Research on path generation and optimization of dynamic continuous descending approach

GONG Fengxun, GAO Songsong

2021, 39(6):  1-6. 

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The benefit of civil aviation transportation can be improved by efficiently planning the safe continuous descending approach（CDA） operation path. Based on the analysis of CDA force balance state, along with the aircraft descent data and descent velocity profile, a dynamic CDA path generation model is constructed. The descent airspace is divided into horizontal and vertical intervals, and a certain height of the descent airspace is represented by a concentric ring structure to realize the 3D presentation of the CDA path generation model structure and to analyze the generation characteristics of the CDA path. On the basis of the difference region between standard descent airspace and terminal area descent airspace, a path range screening model is constructed, and its feasibility is verified by random simulation of CDA paths. The CDA path is screened by selecting descent path points. The optimal CDA paths are obtained through the restriction of the descent turning angle, the constraint of aircraft's force balance and the regulation of flight segment distance. Multiple optimal CDA paths can be obtained from different top of descent(TOD) points to achieve safe descent of multiple aircraft in the same terminal airspace.

Analysis of field signal of glide path antenna based on drone 

QU Chunqing

2021, 39(6):  7-13. 

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Glide path(GP) signal assessment is made via a virtual site modelling and real site monitoring. The testing area is located through the space signal radiation pattern which is obtained according to the characteristics of antenna array. Signals are received in space dynamically by an industrial drone with airborne signal receiver. The space sampling location is sited by WGS -84 coordinate system. The mathematical model and testing result are compared, and the test error of height is offset. The height of the zero point of the difference in depth of modulation of the fixed section of the GP path is achieved precisely by hovering multi-rotor drone along with GPS positioning. The value of threshold crossing height(TCH) is fitted according to the algorithm. The result shows that TCH achieved by drone is not totally identical with the value reported by flight checking. Also, TCH tested by drone is slightly lower than the calculation result of ideal condition.

Research of Spark dynamic resource scheduling strategy in heterogeneous environment

WU Renbiao, LIU Bei, JIA Yunfei

2021, 39(6):  14-19. 

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Aiming at the problem that the Spark does not consider the performance differences of nodes under heterogeneous cluster, which leads to unbalanced node load in multi-job scenarios and reduces job execution efficiency, a Spark dynamic resource scheduling strategy based on the load of heterogeneous cluster nodes is proposed. First, according to the static and dynamic load information of the node at runtime, the heterogeneous cluster nodes load evaluation index is established to obtain the real -time load of the node during cluster operation. Then, the resource manager Standalone of Spark is modified to improve the sequencing strategy. Finally, the dynamic resource scheduling strategy based on heterogeneous cluster node load is implemented. The experimental results show that compared with the default scheduling strategy，the proposed strategy effectively mitigate the load unbalanceness among heterogeneous cluster nodes and improves the job execution efficiency.

Flight delay visualization system based on ES-Redis 

QU Jingyi , CHEN Xuyang , JU Peng , LIU Fang , ZHANG Xiongwei

2021, 39(6):  20-27. 

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Aiming at the problem that a large amount of data in the system leads to slow data retrieval and lack of realtime, a flight delay visualization system based on elasticsearch(ES)- Redis is designed. This paper fully integrates the advantages of MySQL, ES and Redis, the flight data statistics is realized combining statistical query function of MySQL and the rich visual interface of Echarts. The real-time data retrieval is realized by ES and Redis, and the data processing speed of ES-Redis is more than 10 times that of MySQL. The Hybrid algorithm is used to realize the cache replacement of ES-Redis query mode, further improving the response speed of the system.

Risk assessment for ATC operation system based on PSR and unascertained measurement

YUE Rentian, GAO Jing

2021, 39(6):  28-32. 

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The air traffic control(ATC) operation system is complex and therefore difficult to conduct risk assessment by traditional index construction system and methods. By analyzing the characteristics of control operation process, pressure-state-response(PSR) model is used to determine 15 risk assessment indexes for 3 categories. Informa, tion entropy theory is employed to determine the weight of each indicator, a linear unascertained measurement function is constructed to calculate a single-index measurement evaluation matrix and a multi-index compre  hensive evaluation vector. Finally, a risk assessment of a certain regional regulatory unit is conducted. The risk level is determined according to the confidence criterion, and the evaluation result is in line with actual results, which verifies the effectiveness and practicability of the method.

Frequency tracking control strategy based on fuzzy neural network PI control

GAO Jianshu, ZHANG Qinwei , YAN Wen

2021, 39(6):  33-37. 

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Aiming at the frequency detuning problem of the magnetic coupling resonant wireless charging system and the shortcomings of existing resonance frequency adjustment methods, a resonant frequency tracking control strategy based on fuzzy neural network proportional integral (PI) control is proposed. Matlab/Simulink is used to build the system model, to simulate and analyze the proposed control strategy. Simulation results show that compared with the traditional PI control and fuzzy PI control, the fuzzy neural network PI control has the advantages of faster speed and shorter adjustment time for the system, and has smallest overshoot and shortest adjustment time under disturbance, which further verifies the effectiveness and better anti-interference ability of the proposed control strategy

Air itinerary calculation system based on multi-factor bidirectional search method

ZHU Jiabin , YANG Yongkai , LIU Jun

2021, 39(6):  38-42. 

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In order to improve the performance and efficiency of air itinerary query and ensure the availability of connecting flight query results, a multi-factor bidirectional search method is designed. This method upgrades route network map to flight network map, transforms one-way search algorithm to bidirectional search algorithm, and constructs multi-factor constraints for pruning by introducing flight information, class status information, fare information, etc. As a result, this method accelerates the construction of connecting flight query and is applied to design an air itinerary calculation system. According to engineering practice, the designed system solves the low performance and low availability caused by the larger search space, realizes high performance and high availability.

Research on information sharing model of civil aviation security based on blockchain 

JU Chenyang , FENG Wengang , HE Xiaochun

2021, 39(6):  43-48. 

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In order to solve the "data island" problem of traditional civil aviation information sharing mode, this paper summarizes and analyzes the current situation and problems of civil aviation security information sharing. According to the actual demand of civil aviation security, the blockchain model of civil aviation security information sharing is constructed. This paper studies the organizational structure, logical structure, sharing process, application scenarios and difficulties, proposes the application scenario of civil aviation security information sharing blockchain fusion, and constructs a new model of civil aviation information sharing. The research results show that the information sharing model of civil aviation security based on blockchain can make up for the defects of the traditional civil aviation information sharing model, and provide a new idea for the application of blockchain technology in civil aviation security.

Experimental study on hydrophobic ice suppression performance of modified emulsified asphalt

ZHAO Fangran, ZHOU Shengliang, HUO Haifeng

2021, 39(6):  49-53. 

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 Modified emulsified asphalt is prepared using emulsified asphalt as the matrix material, adding hydrophobic and ice-melting material, and spraying it on the asphalt pavement to study its deicing performance. The research results show that the modified emulsified asphalt has good hydrophobic properties, and the pavement contact angle can reach 95.6°; the pavement-ice cohesive force attenuation rate can reach 54.1%, and the modified emulsified asphalt coating has little effect on the friction coefficient of the asphalt pavement. The porous material absorbs the ice-melting material, has a good slow-release effect, effectively reduces the freezing point, and has a good ice-melting capacity, which has a better application prospect for deicing and snow removal on airport runways

Airworthiness Column

Flight test on climb performance of normal category airplane 

WANG Faliang , ZHANG Yu , ZHANG Miaochan

2021, 39(6):  54-58. 

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Climb capability is a key indicator of aircraft performance. Firstly, based on interpretation of airworthiness regulations and advisory circular, flight test is conducted on climb performance of DA42NG clean configuration to present whole procedure of test method and data processing. Secondly, climb performance parameters in Airplane Flight Manual are revised respectively according to flight status and atmospheric conditions simultaneously. Finally, flight test data and flight manual data are compared. The best climb speed measured in flight test is slightly higher than that listed in Airplane Flight Manual, while the best climb rate is slightly lower. Analyses of accuracy-influencing factors show that differences between the measured data and manual data are acceptable. Research results are in line with prediction. The test and data processing methods can provide reference and guide for airworthiness certification and verification, as well as testing flight of similar of types aircraft.

Logic connotation and application of MSG-3 analysis integrating AHM concept

HUANG Jun , GU Jiaxu

2021, 39(6):  59-64. 

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In April 2018, IP180 was officially adopted by International Maintenance Review Board Policy Board (IMRBPB) for guiding main manufacturers to replace traditional scheduled task and combined with MSG-3 and aircraft health management(AHM) techniques for improving maintenance efficiency. Currently, main manufacturers in China have not fully considered application scenarios of AHM system at the beginning of model design, and there are still some preconditions of combining AHM with MSG -3 that need clarification. Based on the knouledge of MSG-3 and IP180, technical key points and specific steps of AHM related analysis logic are elucidated, key links of aircraft maintenance planning are identified, preconditions and implementation requirements are clarified and reference for the implementation of AHM scheme is provided.