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Risk evaluation for the task transfer of an aircraft maintenance program based on a multielement connection number

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Frontiers of Engineering Management 2024年第1期11卷 16-31页

作者： Tao LIU Zhibo SHI Huifen DONG Jie BAI Yu YAN college of Electronics Information and automation Civil Aviation University of ChinaTianjin 300300China college of Airworthiness Civil Aviation University of ChinaTianjin 300300China

This paper proposes a framework for evaluating the efficacy and suitability of maintenance programs with a focus on quantitative risk assessment in the domain of aircraft maintenance task transfer. The analysis is anchored in the principles of Maintenance Steering Group-3 (MSG-3) logic decision paradigms. The paper advances a holistic risk assessment index architecture tailored for the task transfer of maintenance programs. Utilizing the analytic network process (ANP), the study quantifies the weight interrelationships among diverse variables, incorporating expert-elicited subjective weighting. A multielement connection number-based evaluative model is employed to characterize decision-specific data, thereby facilitating the quantification of task transfer-associated risk through the appraisal of set-pair potentials. Moreover, the paper conducts a temporal risk trend analysis founded on partial connection numbers of varying orders. This analytical construct serves to streamline the process of risk assessment pertinent to maintenance program task transfer. The empirical component of this research, exemplified through a case study of the Boeing 737NG aircraft maintenance program, corroborates the methodological robustness and pragmatic applicability of the proposed framework in the quantification and analysis of mission transfer risk.

关键词： risk evaluation maintenance steering group analytic network process task transfer maintenance program

Effects of mixed aerosol on the path loss of NLOS UV communication system

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Optoelectronics Letters 2024年第9期20卷 549-559页

作者： MA Yuzhao ZHOU Jingyi Tianjin Key Laboratory for Advanced Signal Processing Civil Aviation University of ChinaTianjin 300300China college of Electronic Information and automation Civil Aviation University of ChinaTianjin 300300China

Performance of non-line-of-sight(NLOS)ultraviolet(UV)communication is closely related with the communication range,system geometry and the atmosphere aerosol *** this paper,we investigate the path loss of the NLOS UV ... 详细信息

关键词： communication properties. NLOS

Numerical study on influence of protrusion heights on Reynolds stress and viscous stress variations in turbulent vortical structures

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Chinese Journal of Aeronautics 2024年第9期37卷 59-71页

作者： Zhiping LI Long HE Jingsai ZHOU Yueren ZUO Yao YIN Peng ZHANG Bo MENG Research Institute of Aero-Engine Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBejing 100191China Institute of Acoustics Chinese Academy of SciencesBeijing 100190China college of aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China AECC Hunan aviation Powerplant Research Institute Zhuzhou 412002China

Analysing the infuence mechanism of the riblet protrusion height on turbulent drag components is more beneficial in organising the vortical structure over the riblet ***,the Large Eddy Simulation(LES)is used to investigate the vortex structure over the rib-let surface with different protrusion ***,the variations of Reynolds stress and viscous shear stress in a turbulent channel are *** a result,the drag reduction rate increases from 3.4%when the riblets are completely submerged in the turbulent boundary layer to 7.9%when the protrusion height is *** analysis shows that the protrusion height affects the streamwise vortices and the normal diffusivity of spanwise and normal vortices,thus driving the variation of Reynolds *** with the smooth surface,the vorticity strength and the number of streamwise vortices are weakened near the wall but increase in the logarithmic layer with increased protrusion ***,the normal diffusivity of spanwise vorticity decreases with the increase of protrusion height,and the normal diffusivity of normal vorticity is the smallest when the protrusion height is ***,the protrusion height affects the velocity gradient of the riblet tip and riblet valley,thus driving the variation of viscous shear *** the increase of protrusion height,the velocity gradient of the riblet tip increases dramatically but decreases in the riblet valley.

关键词： Riblet Dragreduction Protrusion height Vortical structure Vortexdiffusivity Reynolds stress Viscous stress

Transient state analysis of a rub-impact rotor system during maneuvering flight

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Chinese Journal of Aeronautics 2024年第7期37卷 236-251页

作者： Jun WANG Yunfei LIU Zhaoye QIN Liang MA Fulei CHU Beijing Key Laboratory of Health Monitoring and Self-Recovery for High-End Machinery Equipment Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China college of aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China

Maneuvering flight substantially affects the dynamic behavior of rotors;particularly,such flight may cause rubbing between a rotor and stator,which is one of the most serious damages in aircraft *** this paper,a nonlinear dynamic model for describing the dynamic characteristics of a rub-impact rotor system during maneuvering flight is established based on the Lagrange ***,numerical simulations employing the Newmark method are performed,delving into the detailed discussion of the influence of parameters such as rotational speed and maneuvering flight on the transient and steady-state responses of the rotor *** effect mechanism of maneuver load and its coupling with rub impact is *** results show that the impact response induced by maneuvering flight is more obvious in the subcritical state than in the supercritical *** additional stiffness and damping are also induced;in particular,the additional damping has a coupling ***,the rub impact imposes an additional constraint on the rotor system,thereby weakening the influence of the maneuver load and becoming the major factor that determines the dynamic behavior of the rotor system at high speeds.

关键词： Maneuvering flight Rub impact Rotor system Dynamic response Impact response

CMAS-phobic and infiltration-inhibiting protective layer material for thermal barrier coatings

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Journal of Advanced Ceramics 2024年第8期13卷 1254-1267页

作者： Shjun Meng Lei Guo Hongbo Guo Yuanpeng Wang Hongli Liu School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Advanced Joining Technology Key Lab of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin300072China School of Materials Science and Engineering Beihang UniversityBeijing 100191China college of aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China

Calcium-magnesium-alumina-silicate(CMAS)corrosion has attracted special attention in the thermal barrier coating(TBC)*** high temperatures,when CMAS melts,it adheres to the coating surface and penetrates the interior,severely destroying the *** this study,a promising CMAS-phobic and infiltration-inhibiting material,GdPO4,on which molten CMAs is difficult to wet and penetrate,was *** desirable attributes are explained by analyzing the material characteristics of GdPO_(4) and its interfacial reaction with ***4 is demonstrated to have low surface energy,making it difficult for molten CMAS to wet and adhere to the *** in contact with molten CMAS,a double-layer structured reaction layer consisting of an acicular upper sublayer and a compact lower sublayer is formed on the GdPO4 surface,which can effectively impede molten CMAS spreading and ***-principles calculation results revealed that the reaction layer has low surface energy and low adhesion to CMAS,which are favorable for molten CMAS ***,the formation of the reaction layer increases the viscosity of the molten CMAS,which can increase melt wetting and ***,GdPO4,which exhibits excellent CMAS-phobicity and infiltration-inhibiting ability,is a promising protective layer material for TBCs against CMAS adhesion and attack.

关键词： thermal barrier coatings(TBCs) calcium-magnesium-alumina-silicate(CMAS)-phobicity GdPO_(4) interface reaction layer first-principles calculation

Adaptive Trajectory Tracking Control for Nonholonomic Wheeled Mobile Robots:A Barrier Function Sliding Mode Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 1007-1021页

作者： Yunjun Zheng Jinchuan Zheng Ke Shao Han Zhao Hao Xie Hai Wang the School of Mechanical Engineering Hefei University of TechnologyHefei 230009China the School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyHawthorn VIC 3122Australia the School of civil aviation Northwestern Polytechnical UniversityXi’an 710072China the Shanghai Aerospace Control Technology Institute Shanghai 201109 the School of automation Science and Electrical Engineering Beihang UniversityBeijing 100191China the college of Science HealthEngineering and EducationMurdoch UniversityPerth WA6150Australia

The trajectory tracking control performance of nonholonomic wheeled mobile robots(NWMRs)is subject to nonholonomic constraints,system uncertainties,and external *** paper proposes a barrier function-based adaptive sliding mode control(BFASMC)method to provide high-precision,fast-response performance and robustness for *** with the conventional adaptive sliding mode control,the proposed control strategy can guarantee that the sliding mode variables converge to a predefined neighborhood of origin with a predefined reaching time independent of the prior knowledge of the uncertainties and disturbances *** advantage of the proposed algorithm is that the control gains can be adaptively adjusted to follow the disturbances amplitudes thanks to the barrier *** benefit is that the overestimation of control gain can be eliminated,resulting in chattering ***,a modified barrier function-like control gain is employed to prevent the input saturation problem due to the physical limit of the *** stability analysis and comparative experiments demonstrate that the proposed BFASMC can ensure the prespecified convergence performance of the NWMR system output variables and strong robustness against uncertainties/disturbances.

关键词： Adaptive sliding mode barrier function nonholonomic wheeled mobile robot(NWMR) trajectory tracking control

Research method of circuit fault diagnosis based on FCM

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中南大学学报（自然科学版） 2009年第S1期40卷 290-294页

作者：周德新李伟 college of aeronautical automation Civil Aviation University of China

Using fuzzy C cluster mean (FCM), fuzzy theory and neural network, a fault diagnosis method was proposed, which was based on fuzzy C-means clustering algorithm of neural network that was applied in non-linear analog circuits and in diagnoses the ARNIC 429 reception circuit of aviation aircraft avionics. The C cluster algorithm can make the amount of the fuzzy rule automatically and can create an initial fuzzy rule database of fault diagnosis. A type of fuzzy neural network and a fault tree were generated. The algorithm avoids the disadvantage that gets into the part of optimum circumstance. A validate application was implemented, which proves that the method is effective. Therefore, the method is superior to the traditional methods in fault diagnosis, and the efficiency is heavily improved.

关键词： C cluster algorithm neural network analog circuit fault diagnosis

Stability and performance analysis of a jump linear control system subject to digital upsets

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Chinese Physics B 2015年第4期24卷 6-15页

作者：王蕊孙辉马振洋 Tianjin Key Laboratory for civil Aircraft Airworthiness and Maintenance Civil Aviation University of China college of aeronautical automation Civil Aviation University of China

This paper focuses on the methodology analysis for the stability and the corresponding tracking performance of a closed-loop digital jump linear control system with a stochastic switching signal. The method is applied to a flight control system. A distributed recoverable platform is implemented on the flight control system and subject to independent digital upsets. The upset processes are used to stimulate electromagnetic environments. Specifically, the paper presents the scenarios that the upset process is directly injected into the distributed flight control system, which is modeled by independent Markov upset processes and independent and identically distributed （IID） processes. A theoretical performance analysis and simulation modelling are both presented in detail for a more complete independent digital upset injection. The specific examples are proposed to verify the methodology of tracking performance analysis. The general analyses for different configurations are also proposed. Comparisons among different configurations are conducted to demonstrate the availability and the characteristics of the design.

关键词： stochastic process stability and performance analysis jump linear system digital upsets

A new method of single celestial-body sun positioning based on theory of mechanisms

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Chinese Journal of Aeronautics 2016年第1期29卷 248-256页

作者： Zhang Wei Xu Xiaofeng Wu Yuanzhe Airport college Civil Aviation University of China Tianjin 300300China aviation Ground Special Equipment Research Base Tianjin 300300China aeronautical automation college Civil Aviation University of ChinaTianjin 300300China aeronautical Engineering college Civil Aviation University of ChinaTianjin 300300China

Considering defects of current single celestial-body positioning methods such as discon- tinuity and long period, a new sun positioning algorithm is herein put forward. Instead of tradi- tional astronomical spherical trigonometry and celestial coordinate system, the proposed new positioning algorithm is built by theory of mechanisms. Based on previously derived solar vector equations （from a C1R2p2 series mechanism）, a further global positioning method is developed by inverse kinematics. The longitude and latitude coordinates expressed by Greenwich mean time （GMT） and solar vector in local coordinate system are formulated. Meanwhile, elimination method of multiple solutions, errors of longitude and latitude calculation are given. In addition, this algo- rithm has been integrated successfully into a mobile phone application to visualize sun positioning process. Results of theoretical verification and smart phone＇s test demonstrate the validity of pre- sented coordinate＇s expressions. Precision is shown as equivalent to current works and is acceptable to civil aviation requirement. This new method solves long-period problem in sun sight running fix- ing and improves applicability of sun positioning. Its methodology can inspire development of new sun positioning device. It would be more applicable to be combined with inertial navigation systems for overcoming discontinuity of celestial navigation systems and accumulative errors of inertial nav- igation systems.

关键词： Celestial navigation Inverse kinematics Longitude and latitude coordinates Mechanisms Navigation systems Position measurement Single celestial-body posi-tioning Sun