基于编队控制的自适应HELLO更新算法

在无人机(UAVs)编队自组织网络中,针对无人机之间位置信息更新周期不合理,从而导致编队控制不稳定和控制开销过大的问题,提出一种基于无人机编队控制的自适应HELLO更新算法。该算法应用编队控制稳定性理论推导出无人机组成期望编队的控制延时上限,结合该延时上限和编队运动状态自适应地设定HELLO更新周期。仿真结果表明,本文提出的算法与固定HELLO更新周期算法相比,既能保证在组编控制过程的稳定性,又能实时维护稳定阶段的链路,并且显著减少网络中不必要的控制开销。      

反导多传感器协同任务规划综述

针对反导作战多传感器协同任务规划的相关问题,结合反导作战的特点,探讨反导作战信息处理过程与多传感器协同任务规划的关系,并分析多传感器协同任务规划的内涵;在此基础上,梳理出多传感器协同任务规划涉及的关键技术,并综述多源信息综合处理、多传感器协同部署、协同跟踪、协同引导和协同识别等关键技术的研究现状;最后就多传感器协同任务规划的发展提出一些建议。     

一种适用于大场景圆迹环扫SAR的改进CS成像算法

在宽测绘带圆迹环扫合成孔径雷达(CSSAR)中,目标斜距表示形式复杂,测绘带内距离徙动(RCM)变化剧烈均给成像处理引入难点。针对上述问题,根据圆迹环扫SAR平台的运动特性,使用高阶逼近的方法建立圆弧曲线模型下的回波信号斜距方程,并以导出的二维频谱高阶近似解析表达式为基础,考虑大场景下的距离徙动空变问题,对空变的斜距历程进行详细的分析,并提出了一种适用于大场景圆迹环扫SAR的改进线性调频变标(CS)成像算法。仿真结果说明,曲线模型的斜距方程精度较高,该算法能够精确校正空变的距离徙动,对较大场景取得了较好的成像效果。     

一种无人机旋翼设计方法

为了提高多旋翼无人机的航时,本文提出了一种无人机旋翼设计方法.该方法根据给定的爬升速度、旋翼转速、拉力、旋翼直径、桨叶数、翼型,能够计算出最大力效旋翼的几何特性,包括弦长分布、桨叶角分布.利用该方法设计了某型无人机的旋翼,得到了桨叶角和弦长沿径向的分布.制作了旋翼模型,并且开展了旋翼台架试验.在不同转速下,测量出拉力、...     

某型双座电动飞机设计与试验

沈阳航空航天大学一直致力于新能源电动飞机的研制,某型双座轻型电动飞机于2012年6月立项研制,该型电动飞机采用一台40 kW稀土永磁同步直流电机作为动力装置,全复合材料机体和板簧起落架结构。巡航升阻比24.1,起飞总重500 kg,最大飞行速度160 km/h,巡航速度110 km/h。该型电动飞机具有零排放、低噪声、运行成本低、使用维护方便等特点。参照中国民航CCAR-21部和美国ASTM标准,完成了电动飞机型号设计批准书TDA和生产许可PC取证。     

Research on failure criterion of composite based on unified macro- and micro-mechanical model

A new unified macro- and micro-mechanics failure analysis method for composite structures was developed in order to take the effects of composite micro structure into consideration. In this method, the macro stress distribution of composite structure was calculated by commercial finite element analysis software. According to the macro stress distribution, the damage point was searched and the micro-stress distribution was calculated by reformulated finite-volume direct averaging micromechanics (FVDAM), which was a multi-scale finite element method for composite. The micro structure failure modes were estimated with the failure strength of constituents. A unidirectional composite plate with a circular hole in the center under two kinds of loads was analyzed with the traditional macro-mechanical failure analysis method and the unified macro- and micro-mechanics failure analysis method. The results obtained by the two methods are consistent, which show this new method’s accuracy and efficiency.     

An improved approach to model regional ionosphere and accelerate convergence for precise point positioning

Given the severe effects of the ionosphere on global navigation satellite system (GNSS) signals, single-frequency (SF) precise point positioning (PPP) users can only achieve decimeter-level positioning results. Ionosphere-free combinations can eliminate the majority of ionospheric delay, but increase observation noise and slow down dual-frequency (DF) PPP convergence. In this paper, we develop a regional ionosphere modeling and rapid convergence approach to improve SF PPP (SFPPP) accuracy and accelerate DF PPP (DFPPP) convergence speed. Instead of area model, ionospheric delay is modeled for each satellite to be used as a priori correction. With the ionospheric, wide-lane uncalibrated phase delay (UPD) and residuals satellite DCBs product, the wide-lane observations for DF users change to be high-precision pseudorange observations. The validation of a continuously operating reference station (CORS) network was analyzed. The experimental results confirm that the approach considerably improves the accuracy of SFPPP. For DF users, convergence time is substantially reduced.     

新军事变革中航空武器装备体系的发展

简要介绍了近年来世界新军事变革过程中各主要军事强国航空武器装备体系的发展变化和特点.据此对未来航空武器装备体系的发展趋势提出了看法.     

天问一号探测器高动态着陆惯导系统设计与试验

考虑到火星探测任务着陆过程动态变化大,稀薄大气环境下开伞会对探测器产生剧烈晃动,为此天问一号探测器研制了一套高动态着陆惯导系统,从硬件产品、使用时序到导航算法方面均进行了针对性设计,以适应着陆过程中的高动态环境.此外,为验证天问一号探测器高动态着陆惯导系统的性能,设计了模拟火星开伞工况的火箭弹高空开伞试验,结果表明该高...     

倾转旋翼机模型缝合鲁棒控制律设计研究

从研究倾转旋翼机的飞行动力学模型入手,通过引入模型缝合的思想,利用非线性的方法实现由有限固定线性模型拟合任意工作点处的模型响应,提高了倾转旋翼机飞行动力学计算的实时性,并得到多模型控制的模型集;其次基于规范互质分解理论、H∞回路成形设计技术对多输入多输出系统进行通道解耦控制研究,针对不同飞行工况的工作点分别设计H∞回路成形控制器.最后,采用加权求和的控制策略实现控制律的平滑切换,通过仿真验证了设计的多模型控制系统具有良好的控制能力.