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Chinese Journal of Aeronautics 2019年第10期32卷 2286-2298页

作者： Shaoqi WANG Dongli MA Muqing YANG Liang ZHANG Guanxiong LI School of Aeronautic Science and Engineering Beihang University

Solar-powered aircraft have attracted great attention owing to their potential for longendurance flight and wide application *** to the particularity of energy system,flight strategy optimization is a significant way to enhance the flight performance for solar-powered *** this study,a flight strategy optimization model for high-altitude long-endurance solar-powered aircraft was *** model consists of three-dimensional kinematic model,aerodynamic model,energy collection model,energy store model and energy loss *** solve the nonlinear optimal control problem with process constraints and terminal constraints,Gauss pseudo-spectral method was employed to discretize the state equations and constraint *** a typical mission flying from given initial point to given final point within a time interval was *** indicate that proper changes of the attitude angle contribute to increasing the energy gained by photovoltaic *** of gravitational potential energy can partly take the role of battery *** these two measures,the optimized flight strategy can improve the final state of charge compared with current constant-altitude constant-velocity *** optimized strategy brings more profits on condition of lower sunlight intensity and shorter daytime.

关键词： Battery pack flight strategy optimization Gauss pseudo-spectral method Photovoltaic cell Solar-powered aircraft

flight dynamics characteristics of canard rotor/wing aircraft in helicopter flight mode

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Chinese Journal of Aeronautics 2019年第7期32卷 1577-1587页

作者： Honggang GAO Ao HE Zhenghong GAO Yang NA Yangping DENG School of Aeronautics Northwestern Polytechnical University

The aerodynamic layout of the Canard Rotor/Wing(CRW) aircraft in helicopter flight mode differs significantly from that of conventional helicopters. In order to study the flight dynamics characteristics of CRW aircraft in helicopter mode, first, the aerodynamic model of the main rotor system is established based on the blade element theory and wind tunnel test results. The aerodynamic forces and moments of the canard wing, horizontal tail, vertical tail and fuselage are obtained via theoretical analysis and empirical formula. The flight dynamics model of the CRW aircraft in helicopter mode is developed and validated by flight test data. Next, a method of model trimming using an optimization algorithm is proposed. The flight dynamics characteristics of the CRW are investigated by the method of linearized small perturbations via Simulink. The trim results are consistent with the conventional helicopter characteristics, and the results show that with increasing forward flight speed, the canard wing and horizontal tail can provide considerable lift,which reflects the unique characteristics of the CRW aircraft. Finally, mode analysis is implemented for the linearized CRW in helicopter mode. The results demonstrate that the stability of majority modes increases with increasing flight speed. However, one mode that diverges monotonously,and the reason is that the CRW helicopter mode has a large vertical tail compared to the conventional helicopter. The results of the dynamic analysis provide optimization guidance and reference for the overall design of the CRW aircraft in helicopter mode, and the model developed can be used for control system design.

关键词： Canard rotor/wing aircraft Dynamics analysis flight dynamics Helicopter Linearization Model building

flight behavior of the sycamore lace bug, Corythucha ciliata, in relation to temperature, age, and sex

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Journal of Integrative Agriculture 2019年第10期18卷 2330-2337页

作者： LU Shao-hui WEI Mei-cai YUAN Guo-jun CUI Jian-xin GONG Dong-feng Laboratory of Insect Systematics and Evolutionary Biology Central South University of Forestry and TechnologyChangsha 410000P.R.China Henan Academy of Forestry Zhengzhou 450000P.R.China Henan Institute of Science and Technology Xinxiang 453000P.R.China

The flight capacity of different ages and sexes of the sycamore lace bug, Corythucha ciliata, was studied at different temperatures using a flight mill system. The results of regression analysis showed a significant effect of temperature on flight distance (P=0.0082). Temperature did not influence flight duration (P=0.212) or flight speed (P=0.175). The mean flight distance (1 024 m) and mean flight duration were the greatest at 25.2°C. The age of C. ciliata had a significant influence on flight distance (P=0.0005), flight duration (P=0.0005) and flight speed (P=0.026). The 12-d-old adult had the greatest flight distance (887 m), duration (3 875 s) and speed (0.22 m s^–1). flight distances and flight duration of females were significantly longer than that of males. However, the male had significantly greater flight speed than the female. The insect appears to be capable of long distance flights. The understanding of the optimal age and temperature for the flight of this insect through this study provides a foundation for better management of the insect in China.

关键词： Corythucha ciliata flight capacity tethered flight temperature age and sex

flight activity promotes reproductive processes in the fall armyworm,Spodoptera frugiperda

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Journal of Integrative Agriculture 2021年第3期20卷 727-735页

作者： GE Shi-shuai HE Wei HE Li-mei YAN Ran ZHANG Hao-wen WU Kong-ming State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops Institute of Applied EcologyFujian Agriculture and Forestry UniversityFuzhou 350002P.R.China State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100193P.R.China College of Plant Protection Henan Agricultural UniversityZhengzhou 450002P.R.China

The fall armyworm(FAW),Spodoptera frugiperda(Lepidoptera:Noctuidae),has invaded many countries in Africa and Asia since 2016,posing a major threat to world food ***-distance migration and strong reproductive ability form the biological basis of its rapid population expansion,but the relationship between the flight and reproduction of FAW has not been studied in ***,an empirical assessment of this relationship in an invasive FAW population in China found that 1-3-day-old adults which had undergone 10-h tethered flights had a significantly shorter pre-oviposition period and greater oviposition synchronization,but did not show any differences in fecundity,oviposition period,mating percentage or other reproductive *** studies on moths after 1.25-15-h tethered flights indicated that the reproductive process of adults could be fully triggered by flight activity longer than 2.5 *** of the reproductive organs also showed that tethered flight promoted ovarian and testicular development of *** results show that appropriate moth flight activity significantly speeds up the reproductive process of FAW,which increases our knowledge on its migratory biology in relation to regional outbreaks.

关键词： flight reproduction migration invasion biology movement ecology

flight Safety System Evaluation and Optimal Linear Prediction

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Transactions of Nanjing University of Aeronautics and Astronautics 2019年第2期36卷 205-213页

作者： DING Songbin GU Qianqian LIU Jiayu College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China Aeronautical Engineering Academy Binzhou UniversityBinzhou 256600P.R.China

The complexity of flight safety system is usually affected by a variety of *** uncertainty of overall security situation of flight safety system are hardly *** this work,flight safety assessment index system is firstly established based on software hardware environment liveware management(SHELM)*** flight safety assessment is also carried out with matter-element theory algorithm to obtain safety *** to correlation degree values of each evaluation index,key indexes affected flight safety are *** the assumption that the flight safety system is a linear dynamic system and combining the above evaluation analysis,Kalman filter algorithm is used to carry out prediction analysis on security situation.A simulation analysis is carried out based on an actual flight safety situation of an *** results show that the security state of airline flight safety system in a short period of time can be obtained,and main factors affecting flight safety are found *** provides a viable way for airlines to further strengthen flight safety management.

关键词： flight safety flight safety assessment and prediction software hardware environment liveware management(SHELM)model matter-element theory Kalman filter theory

A flight experimental platform for synchrophasing control based on a small propeller UAV

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Science China(Technological Sciences) 2018年第12期61卷 1915-1924页

作者： CAO YunFei HUANG XiangHua SHENG Long WANG ZhiPeng College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China JiangSu Province Key Laboratory of Aerospace Power System Nanjing 210016 China

Turboprop engine has the advantages of high efficiency and high thrust, but it has not been widely used in the civil field because of the noise excited by the low speed propellers. Propeller synchrophasing control is an active noise control method without increasing the weight of the airframe, which can attenuate the noise level in the cabin by controlling the relative phase among multiple propellers. It is generally accepted that altitude and airspeed have a great influence on the noise reduction effect of propeller synchrophasing, but there is no theoretical research about how these two factors affect the noise level. Therefore, flight experiment is considered to be a credible way. However, flight experiments of propeller synchrophasing control in turboprop aircraft have been accomplished in few countries due to enormous cost and inconvenience. An experimental platform of synchrophasing control based on a two-propeller small unmanned air vehicle(UAV) is proposed which can carry out the flight experiment research in a low-cost way. The phase angle sensor, the FOC-based scheme of motor driving, the all-slave synchrophasing control and the coordination between speed and phase difference control are presented in the UAV platform to meet its synchrophasing control precision requirement, experimental results prove that all of them can significantly enhance the performance of synchrophasing control. Noise characteristics of propellers are studied in the flight experiments, the noise predicted by the noise model is highly consistent with the actual measured noise, which verifies that the noise characteristics of small UAV accord with propeller signature theory. Based on the noise model, propeller synchrophasing has a steady effect to minimizing noise in the UAV platform. These show that the UAV platform is a feasible solution for propeller synchrophasing research.

关键词： propeller synchrophasing noise reduction small UAV flight experimental platform low cost

Influence of Center of Gravity Location on flight Dynamic Stability in a Hovering Tailless FW-MAV: Lateral Motion

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Journal of Bionic Engineering 2020年第1期17卷 148-160页

作者： Loan Thi Kim Au Hoon Cheol Park Department of Smart Vehicle Engineering and Artificial Muscle Research Center Konkuk UniversitySeoul 05029Korea

This paper reports the effect of the Center of Gravity(CG)position on lateral flight dynamic stability of hovering KUBeetle,a tailless FW-MAV,providing further insights on the effects of asymmetries in body mass distribution and wing *** the current study,the standard linearized equations of motion were applied as in the previous work on longitudinal dynamic *** stability derivatives were acquired using the computational fluid dynamic methods via the commercial software of ANSYS *** exists a stable region for CG between 2.6%and 3.5%of the mean chord below the wing pivot point,in which the lateral motion of hovering KUBeetle is passively *** CG below the stable region,because of an unstable oscillatory mode,the lateral motion of the FW-MAV is unstable but can be stabilized using rolling rate *** CG above the stable region,because of a divergence mode,the system remains unstable even with the rolling rate *** with other works on an FW-MAV based on a quasi-steady aerodynamic model and on insect showed similar characteristics for flapping *** is also interesting to note that the asymmetries in body mass and wing kinematics can enlarge the stable region of the system by a non-zero Ixz which approaches the root square of√IxIz,a negative LrNp,and a positive Ix2(Ir+Np).Combining the current result with that of the previous work on longitudinal motion,the most beneficial region of the CG for full 6-DOF flight dynamic stability of hovering KUBeetle was suggested.

关键词： FW-MAV center of gravity flight dynamic stability lateral motion asymmetry computational fluid dynamics bioinspired flight

Influence of Center of Gravity Location on flight Dynamic Stability in a Hovering Tailless FW-MAV:Longitudinal Motion

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Journal of Bionic Engineering 2019年第1期16卷 130-144页

作者： Loan Thi Kim Au Hoon Cheol Park Department of Smart Vehicle Engineering and Artificial Muscle Research Center Konkuk UniversitySeou105029Korea

The influence of Center of Gravity(CG)location on longitudinal dynamic stability of hovering KUBeetle,a tailless Flapping-Wing Micro Air Vehicle(FW-MAV),is reported in this *** rigid-body approximation was assumed,allowing application of the standard equations of motion used for fixed-wing *** each considered location of CG,stability derivatives were obtained using the computational fluid dynamics method via the commercial software of ANSYS *** dynamic stability was studied using technique of eigenvalue *** exists a narrow stable region for CG between 23%-24%of mean chord above the wing pivot point,where the longitudinal hovering of KUBeetle is passively *** CG is located below the stable region,the analysis identifies two subsidence modes and one unstable oscillatory mode,which makes the hovering of KUBeetle ***,it can be stabilized using pitching rate *** CG is located above the stable region,the system yields one stable oscillatory mode,one subsidence mode,and one divergence *** of the divergence mode,the system remains unstable even with the angular rate *** results share similar characteristics to another FW-MAV and *** study may provide a reference for FW-MAV developers.

关键词： center of gravity hovering longitudinal dynamic stability computational fluid dynamics flapping wings bioinspired flight

Two freedom linear parameter varying μ synthesis control for flight environment testbed

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Chinese Journal of Aeronautics 2019年第5期32卷 1204-1214页

作者： Meiyin ZHU Xi WANG Zhihong DAN Song ZHANG Xitong PEI School of Energy and Power Engineering Beihang University Collaborative Innovation Center for Advanced Aero-Engine Science and Technology on Altitude Simulation Laboratory

To solve the problem of robust servo performance of flight Environment Testbed(FET)of Altitude Ground Test Facilities(AGTF) over the whole operational envelope, a two-degree-offreedom μ synthesis method based on Linear Parameter Varying(LPV) schematic is proposed, and meanwhile a new structure frame of μ synthesis control on two degrees of freedom with double integral and weighting functions is presented, which constitutes a core support part of the paper. Aimed at the problem of reference command's rapid change, one freedom feed forward is adopted, while another freedom output feedback is used to meet good servo tracking as well as disturbance and noise rejection; furthermore, to overcome the overshoot problem and acquire dynamic tuning,the integral is introduced in inner loop, and another integral controller is used in outer loop in order to guarantee steady errors; additionally, two performance weighting functions are designed to achieve robust specialty and control energy limit considering the uncertainties in system. As the schedule parameters change over large flight envelope, the stability of closed-loop LPV system is proved using Lyapunov inequalities. The simulation results show that the relative tracking errors of temperature and pressure are less than 0.5% with LPV μ synthesis controller. Meanwhile, compared with non-LPV μ synthesis controller in large uncertainty range, the proposed approach in this research can ensure robust servo performance of FET over the whole operational envelope.

关键词： Altitude ground test facilities flight environment testbed Linear parameter varying Robust control Two-degree-of-freedom μ Synthesis

Fault diagnosis and accommodation for linear parameter-varying in flight control systems

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中南大学学报（自然科学版） 2009年第S1期40卷 247-252页

作者：陈伟姜斌张柯 College of Automation Engineering Nanjing University of Aeronautics and Astronautics

The fault diagnosis and accommodation strategy for a class of linear parameter-varying (LPV) systems were investigated. A fast adaptive fault estimation (FAFE) algorithm for LPV systems module, based on an adaptive observer, proposed to enhance the performance of fault estimation including rapidity and accuracy. Then, the obtained fault estimate was used to construct the fault tolerant control (FTC) law. The design method was formulated as a convex linear matrix inequalities (LMIs) optimization problem. Once the faults are estimated, the fault tolerant controller is implemented as a dynamic output feedback controller. This controller can compensate for the effect of the faults by stabilizing the closed-loop systems. Finally, a helicopter model in a vertical flight with actuator fault was used to the effectiveness of the proposed approach.

关键词： active FTC flight control systems polytopic LPV adaptive observer LMIs