基于蚁群算法的航空器滑行路径优化

通过对南京机场场面结构建立数学模型,构建南京机场场面结构基线模型,设置现行场面结构、滑行和管制规则,通过有向图的方式,将南京机场地面抽象成节点路段型数学模型.针对已建立的场面结构模型,通过对历史场监雷达数据的综合分析,识别机场场面在不同交通态势下的冲突热点区域,并对这些区域的危险程度进行等级划分.在已有的冲突热点区域基础上,对经过热点区域的滑行路径进行优化,构建航空器的滑行避让和选择机制,建立基于最短滑行时间的滑行路径优化模型,采用改进的蚁群算法对模型进行求解,结合南京机场实际运行情况建立仿真系统,最后通过实例验证了算法的可行性和有效性,增加了机场滑行路径选择的多样性和灵活性,提高了机场的运行效率.

一种基于解析敏度的结构多约束优化技术研究

敏度求解是优化设计中最重要且最耗时的环节之一,目前解析法是效率和精度最高的敏度计算方法,但限于其理论复杂性而被商软所摒弃。通过深入系统的理论推导,突破了应力/应变敏度全解析求解难题,并通过引入自适应减缩因子,实现了数学规划法的加速收敛。结合作者前期已经研究完成的位移敏度求解理论,组织了基于解析法的可同时考虑强度和刚度约束的结构多约束优化流程,并以航空结构强度分析与优化系统(HAJIF)为软件平台,采用FORTRAN语言开发了结构多约束优化模块。通过工程机翼的多约束优化案例表明了上述算法稳定性和高效性,优化结果也具有较强的工程实用性。

多目标优化方法辨识伞弹弹道参数

采用状态重构、多目标优化辨识理论 ,利用低空伞弹全弹道测试坐标数据为信息源 ,使理论计算弹道状态变量 (速度、坐标 )与实测 (或准实测 )弹道状态变量在统计意义上充分逼近 ,辨识出影响低空伞弹弹道的关键参数——阻力系数、主伞充满时间、弹射速度和附加质量系数 .经多枚实弹空投测试数据验证 ,表明此方法的处理结果是一致的、有效的 .

APPLICATION OF HYBRID AERO-ENGINE MODEL FOR INTEGRATED FLIGHT/PROPULSION OPTIMAL CONTROL

The real-time capability of integrated flight/propulsion optimal control （IFPOC） is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gramming （SQP）. Firstly, a steady-state hybrid aero-engine model is designed in the whole flight envelope with a dramatic enhancement of real-time capability. Secondly, the aero-engine performance seeking control including the maximum thrust mode and the minimum fuel-consumption mode is performed by SQP. Finally, digital simu- lations for cruise and accelerating flight are carried out. Results show that the proposed method improves real- time capability considerably with satisfactory effectiveness of optimization.

运用CDM系统保障航班正常率

随着时代的发展,经济的进步,各地区的经济往来越来越频繁,而经济活动的范围也在不断的扩大,因此航空运输量在现阶段变得越来越大,航班延误、航空拥堵等问题也逐渐显现出来并得到人们的重视,而CDM(Airport Collaborative Decision Making机场协同决策机制)作为一种新型的航空合作系统,能够为航班的正常运行提供保障。本文笔者就从CDM的优势方面出发,探讨运用CDM保证航班正常率的相关方案,希望为我国的航空运输提供保障,为我国经济的发展助力。

不确定条件下点融合系统进场排序研究

针对进场过程中航空器过点时间不确定导致延误传播的问题,为提升排序方案在实际运行中的鲁棒性和实用性,基于点融合系统分别建立了可对冲不确定性影响的静态和动态排序模型。静态排序模型以排序边延误时间最小和最大飞行时间最小为目标,采用结合了随机机会约束的改进NSGA-II算法进行优化;动态排序模型以最小化总飞行时间为目标,采用基于滑动时间窗的启发式算法对初始方案进行优化。仿真结果显示:具有额外缓冲区的静态和动态排序模型的排序边延误时间相比于传统方法分别降低了38.8%、20.8%;在37.5s的缓冲时间下,静态排序模型的总飞行时间、排序边延误时间、最大飞行时间相比动态排序模型分别降低了4%、19.9%、7.1%。通过损失较少的运行效率能够有效地缓解汇聚航路点的延误传播;其中,静态排序模型相比动态排序模型航空器序列改变量更多,动态排序模型的鲁棒性能更好。

THREE-DIMENSIONAL TRAJECTORY OPTIMIZATION WITH DIRECT METHOD

The principle of direct method used in optimal control problem is introduced. Details of applying this method to flight trajectory generation are presented including calculation of velocity and controls histories. And capabilities of flight and propulsion systems are considered also. Combined with digital terrain map technique, the direct method is applied to the three dimensional trajectory optimization for low altitude penetration, and simplex algorithm is used to solve the parameters in optimization. For the small number of parameters, the trajectory can be optimized in real time on board.

Novel Adaptive Simulated Annealing Algorithm for Constrained Multi-Objective Optimization

In recent years, sinmlated annealing algo-rithms have been extensively developed and uti-lized to solve nmlti-objective optimization problems. In order to obtain better optimization perfonmnce, this paper proposes a Novel Adaptive Simulated Annealing （NASA） algorithm for constrained multi-objective optimization based on Archived Multi-objective Simulated Annealing （AMOSA）. For han-dling multi-objective, NASA makes improverrents in three aspects： sub-iteration search, sub-archive and adaptive search, which effectively strengthen the stability and efficiency of the algorithnm For handling constraints, NASA introduces corresponding solution acceptance criterion. Furtherrrore, NASA has also been applied to optimize TD-LTE network perform-ance by adjusting antenna paranleters; it can achieve better extension and convergence than AMOSA, NS-GAII and MOPSO. Analytical studies and simulations indicate that the proposed NASA algorithm can play an important role in improving multi-objective optimi-zation performance.

Multi-dimensional and Multi-threshold Airframe Damage Region Division Method Based on Correlation Optimization

In order to obtain the image of airframe damage region and provide the input data for aircraft intelligent maintenance,a multi-dimensional and multi-threshold airframe damage region division method based on correlation optimization is proposed.On the basis of airframe damage feature analysis,the multi-dimensional feature entropy is defined to realize the full fusion of multiple feature information of the image,and the division method is extended to multi-threshold to refine the damage division and reduce the impact of the damage adjacent region’s morphological changes on the division.Through the correlation parameter optimization algorithm,the problem of low efficiency of multi-dimensional multi-threshold division method is solved.Finally,the proposed method is compared and verified by instances of airframe damage image.The results show that compared with the traditional threshold division method,the damage region divided by the proposed method is complete and accurate,and the boundary is clear and coherent,which can effectively reduce the interference of many factors such as uneven luminance,chromaticity deviation,dirt attachment,image compression,and so on.The correlation optimization algorithm has high efficiency and stable convergence,and can meet the requirements of aircraft intelligent maintenance.

Multi-objective Thermal Optimization of Dual-input Aeronautic Static Inverter Based on MOEA/D

To solve the multi-variable and multi-objective optimization problem in the thermal design process of the dual-input aeronautic static inverter,an optimization method based on the combination of the multi-objective evolutionary algorithm based on decomposition(MOEA/D)and the fuzzy set theory is proposed.The heat transfer path of the power device is analyzed and an equivalent heat circuit is conducted.We take junction temperature of the power device,mass,and cost of the heat sink as optimization goals,and take the heat sink structure parameters as design variables to conduct thermal optimization based on MOEA/D.This paper carries out a comparative study,and the results show that the proposed improved algorithm can meet the different requirements for multi-objective weights,and have good rapidity and robustness.

双学科(气动/电磁)优化中的遗传算法研究

遗传算法(GA)是一种非传统性,模仿生物的自然选择与进化而形成的一种概率搜索和总体优化的方法.讨论了此算法的要点和关键参数.为应用于多目标和多学科优化的问题,提出了一种综合考虑多目标和多约束的要求,并引入归一化系数和约束函数的罚系数的适应函数.

Comparison of the Sound Power Levels of an Aerodynamically Designed EGV and a State-of-the-Art EGV

Within previous EU projects, possible modifications to the engine components have been investigated, that would allow for an optimised aerodynamic or acoustic design of the EGV （exit guide vanes） of the TEC （turbine exit casing）. However, the engine weight should not be increased and the aerodynamic performance must be at least the same. This paper compares the sound power level of a state-of-the-art TEC （reference TEC） with typical EGVs with an aerodynamically optimised TEC configuration for the engine operating point approach. It is shown that a significant weight reduction （only bladings considered） and reduction in engine length can be achieved but the sound power level for the fundamental tone （lst blade passing frequency） for this acoustically important operating point is increased. It is also shown that the losses of the aerodynamical optimised EGVs are higher for this off design point but significantly lower at the aero design point. Measurements were conducted in the STTF （subsonic test turbine facility） at the Institute for Thermal Turbo machinery and Machine Dynamics, Graz University of Technology. The inlet guide vanes, the LPT （low pressure turbine） stage, and the EGVs have been designed by MTU Aero Engines.

A survey of numerical algorithms for trajectory optimization of flight vehicles

As one of the important components of computational flight mechanics and control,numerical algorithms of trajectory optimization for flight vehicles are currently studied by many researchers in aerospace engineering to completely solve these difficult problems,but few papers on the survey of this research field have been published recently.Based on the investigation of more than one hundred literatures,considering the application perspectives of computational flight mechanics and recent developments of trajectory optimization,the numerical algorithms of trajectory optimizations for aerospace vehicles are summarized and systematically analyzed.This paper summarized the basic principle,characteristics and application for all kinds of current trajectory optimization algorithms;and introduced some new methods and theories appearing in recent years.Finally,collaborative trajectory optimization for many flight vehicles,and hypersonic vehicle trajectory optimization were mainly reviewed in this paper.In the conclusion of this paper,the future research properties are presented regarding to numerical algorithms of trajectory optimization and control for flight vehicles as follows:collaboration and antagonization for many flight vehicles and multiple targets,global,real-time online,high accuracy of 7-D trajectory,considering all kinds of unknown random disturbances in trajectory optimization,and so on.

Efficient aero-structural design optimization: Coupling based on reverse iteration of structural model

Traditional coupled multi-disciplinary design optimization based on computational fluid dynamics/computational structure dynamics(CFD/CSD)aims to optimize the jig shape of aircraft,and general multi-disciplinary design optimization methodology is adopted.No special consideration is given to the aircraft itself during the optimization.The main drawback of these methodologies is the huge expanse and the low efficiency.To solve this problem,we put forward to optimize the cruise shape directly based on the fact that the cruise shape can be transformed into jig shape,and a methodology named reverse iteration of structural model(RISM)is proposed to get the aero-structural performance of cruise shape.The main advantage of RISM is that the efficiency can be improved by at least four times compared with loosely-coupled aeroelastic analysis and it maintains almost the same fidelity of loosely-coupled aeroelastic analysis.An optimization framework based on RISM is proposed.The aerodynamic and structural performances can be optimized simultaneously in this framework,so it may lead to the true optimal solution.The aerodynamic performance was predicted by N-S solver in this paper.Test shows that RISM predicts the aerodynamic and structural performances very well.A wing-body configuration was optimized by the proposed optimization framework.The drag and weight of the aircraft are decreased after optimization,which shows the effectiveness of the proposed framework.

Aerodynamic/mechanism optimization of a variable camber Fowler flap for general aviation aircraft

A conventional Fowler flap is designed to improve the take-off and landing performances of an aircraft. Because the flight states of general aviation aircraft vary significantly. A Fowler flap with a double-sliding track has been designed, which is ca- pable of changing airfoil camber while cruising and climbing as well as meeting low-speed performance requirements. The aerodynamic characteristics of the variable camber Fowler flap were studied by computational simulation, and cambering was found to be beneficial for improving the lift-to-drag ratio when the lift coefficient was larger than the critical value, below which decambering was more effective; this critical value differed somewhat under different conditions. Taking the mecha- nism into account, the take-off and landing configurations were optimized on the basis of the GA （W）-1 airfoil with a 30% chord Fowler flap. Compared with reference configuration, the maximum lift coefficient of optimized take-off configuration was increased by 6.6% as well as the stalling angle and the lift-to-drag ratio were increased by 1.3° and 7.58%, respectively. Moreover, the maximum lift coefficient of the optimized landing configuration was increased by 6.3%, and the stalling angle was increased by 1.1°; however, the nose-down pitching moment of both configurations increased. Similar results were at- rained on a general aviation aircraft wing/body combination nism was established in a computer-aided design system, achieved by the double-sliding track. A 3D model of the variable-camber Fowler flap driving mecha- and the results showed that all design configurations could be

Models of Choosing the Financial Compensation Strategy for Flight Delay

At present, most airlines adopted generally the same amount of compensa- tion strategy when needing to provide financial compensation to all flight delay passengers. However, due to the existence of differences in travel time value, ticket fare, as well as the expectation of compensation for flight delays, the gap between the effect of same amount of compensation and many passengers＇ （especially the high-value ones） expectations is large, it results in that airlines need to pay higher cost of compensation, but the total effect of compensation for passengers are not better. This paper advanced four financial com- pensation strategies for flight delays, summarized their own characteristics, and took into account the interests of both airlines and passengers, built the optimization models of the four financial compensation strategies under the restriction of the airline＇s compensation cost and on the goal of the maximum total effectiveness of the financial compensation to all passengers. Finally, based on the specific circumstances of the flight delays, the paper discussed the method for airline to choose the optimal financial compensation strategy through solving four models and comparing the compensation effectiveness.