【作者】 俞玮；

【导师】 周洲；

【作者基本信息】 西北工业大学 ， 飞行器设计， 2004， 硕士

【摘要】 根据长航时无人机的特殊飞行任务特点和技术要求，在飞行试验阶段，有必要综合考虑飞行环境中各种大气干扰因素的影响，为无人机设计与仿真提供一个真实、适时的风场时空分布模型。同时变化风场中的大展弦比无人机不能当作质点受力考虑，而应作分散受力考虑，需要建立无人机的“有限大小”模型。本文的工作就是围绕飞行环境模拟和无人机动力学仿真展开。具体内容如下： 1．分析了高空长航时无人机的飞行特点，统计了几种的典型航空气象特征，并提出大尺度风场的垂直分层型，最后总结了大气风场的常用数值模拟方法； 2．讨论了以下几种典型风场模型(大尺度均值风模型、Dryden紊流模型、微下击暴流模型和过山气流模型)的物理特征与建模方法，并对单一模型进行复合，建立变化风场模型库，最后讨论了各种模型的真实性与如何应用于飞行仿真； 3．对传统的质点飞机模型做了改进，建立了基于变化风场和“有限大小”概念的无人机动力学模型，讨论“四点法”模型的具体仿真实现方法； 4．首次针对大展弦比无人机，进行变化风场中飞行仿真，讨论各风场模型的真实性及其对飞行性能曲线的影响； 5．介绍了整个仿真软件的原理与算法流程，分析并总结了变化风场中的飞行注意事项。 本文的数值建模方法与实际仿真软件对无人机的总体设计、飞行任务规划及控制器设计等都有实际的参考意义。更多还原

【Abstract】 In consideration of the special mission characteristics and technical requirement of High Altitude Long Endurance Unmanned Aerial Vehicle, an authentic real-time and space-time windfield integrated model is accomplished to take atmosphere environment influences into account. At the same time, we should analyze the dynamics the UAV encounters dispersedly, so the "Finite Scale" Aircraft concept is quoted. The focuses of this paper are on flight environment simulation and high span-chord ratio UAV model. The main contents and endeavour of this paper are as follow:1. The flight characteristics of High Altitude Long Endurance UAV are analyzed, several typical kinds of Aeronautical Weather are ingathered, and the vertical distributing model of Large Scale Windfield is established, traditional numerical simulation methods of atmosphere environment are summarized.2. Typical variable windfield models, such as Large Scale Steady Wind Flow, Downburst, Turbulence, Airflow over mountain, are developed and their physical specialities are discussed. Furthermore, simplex modules are integrated to form complex model. Facticity and application technique to flight simulation are discussed.3. Some improvements are developed to traditional particle aircraft model, and dynamic UAV model based on variable windfield and "Finite Scale Aircraft" concept are established, what’s more the implement algorithm of "four-point" model are described.4. For the first time, flight simulation related to high span-chord ratio UAV based on variable windfield is executed, the facticity of windfield and its influence to flight performance curve are analyzed.5. The principle and algorithm flow of the whole simulating programme are stated, and flight safety precautions in variable windfield and windshear resistance and alleviation technique are analyzed and summarized.The results show that the wind effects are relatively severe and therefore control system design should take this fully into account. This paper gives significant references for UAV conceptual design, flight mission planning and trajectory controlling system design.更多还原