Dynamic simulation of aerial towed decoy system based on tension recurrence algorithm

Dynamic model of aerial towed decoy system is established and simulations are performed to research the dynamic characteristics of the system. Firstly, Kinetic equations based on spinor are built, where the cable is discretized into a number of rigid segments while the decoy is modeled as a rigid body hinged on the cable. Then tension recurrence algorithm is developed to improve computational efficiency, which makes it possible to predict the dynamic response of aerial towed decoy system rapidly and accurately. Subsequently, the efficiency and validity of this algorithm are verified by comparison with Kane's function and further validated by wind tunnel tests.Simulation results indicate that the distance between the towing point and the decoy's center of gravity is suggested to be 5%–20% of the length of decoy body to ensure the stability of system.In up-risen maneuver process, the value of angular velocity is recommended to be less than0.10 rad/s to protect the cable from the aircraft exhaust jet. During the turning movement of aircraft, the cable's extent of stretching outwards is proportional to the aircraft's angular velocity.Meanwhile, the decoy, aircraft and missile form a triangle, which promotes the decoy's performance.     

航空拖曳诱饵系统机动过程缆绳张力仿真

为解决航空拖曳诱饵系统研制过程中拖曳缆绳强度设计问题,对拖曳诱饵系统机动过程缆绳张力进行了仿真研究。仿真中建立了缆绳的质量弹簧阻尼模型和诱饵弹的六自由度动力学模型,研究了直线加速和机动转弯2个典型飞行动作中缆绳受力情况,分析了载机加速度、飞行高度、缆绳弹性模量、缆绳直径等因素对缆绳张力的影响。结果表明：缆绳中张力大小不仅与诱饵弹、缆绳的气动阻力、重力有关,还与它们的惯性力有关;由于张力在缆绳中传递存在时滞性,机动过程中缆绳张力存在波动现象,波动的剧烈程度与载机加速度、缆绳弹性模量、缆绳直径有关;机动转弯过程中,缆绳会承受一个较大的峰值应力,该应力随着转弯角速度的增大而增大。     

航空拖曳诱饵系统的动态特性研究简

 为准确预测航空拖曳诱饵系统能否干扰成功,建立了系统的物理数学模型并对其动态特性进行了仿真研究。应用集中质量法,将柔性拖曳缆绳离散为一系列由阻尼弹簧连接的节点,建立了缆绳的动态模型;对诱饵进行受力分析,建立了诱饵的六自由度模型;提出了缆绳与诱饵的耦合条件,使模型更加精确。分别对诱饵释放过程中,以及释放完成后载机机动时系统的动态特性进行了仿真研究,给出并分析了缆绳的形状、张力和诱饵的姿态角等参数的变化规律。结果表明：为避免出现“鱼钩”现象,应尽可能减小释放诱饵的初速度与载机空速的夹角;应按梯形速度释放诱饵,以使缆绳中拉力的最大值较小。释放完成后,应控制载机最大飞行速度,以避免缆绳进入载机的高温尾喷流区;载机作盘旋时,缆绳在载机的圆形轨迹之外,且载机飞行速率一定时,角速度越大,缆绳向外趋势越大,越有利于避开载机的尾喷流区。     

航空拖曳诱饵系统的动态特性研究

为准确预测航空拖曳诱饵系统能否干扰成功,建立了系统的物理数学模型并对其动态特性进行了仿真研究。应用集中质量法,将柔性拖曳缆绳离散为一系列由阻尼弹簧连接的节点,建立了缆绳的动态模型;对诱饵进行受力分析,建立了诱饵的六自由度模型;提出了缆绳与诱饵的耦合条件,使模型更加精确。分别对诱饵释放过程中,以及释放完成后载机机动时系统的动态特性进行了仿真研究,给出并分析了缆绳的形状、张力和诱饵的姿态角等参数的变化规律。结果表明：为避免出现“鱼钩”现象,应尽可能减小释放诱饵的初速度与载机空速的夹角;应按梯形速度释放诱饵,以使缆绳中拉力的最大值较小。释放完成后,应控制载机最大飞行速度,以避免缆绳进入载机的高温尾喷流区;载机作盘旋时,缆绳在载机的圆形轨迹之外,且载机飞行速率一定时,角速度越大,缆绳向外趋势越大,越有利于避开载机的尾喷流区。     

超视距空战条件下舰载机空中巡逻研究

根据超视距空战条件下舰载机空中巡逻的特点,建立舰载机空中巡逻的战术行为模型；采用蒙特卡洛法对巡逻效果进行模拟统计,分析雷达最远发现距离、巡逻区间距、舰载机定常平飞距离、巡逻飞行航线类型与飞行协同方式对舰载机空中巡逻效果的影响；最终给出超视距协同空战条件下,舰载机空中巡逻的组织方法。     

先进舰载战斗机强度设计技术发展与实践

舰载战斗机是航空母舰上的主要武器,为满足舰面起飞、着舰和停放等要求,舰载机需围绕起落架系统、拦阻钩系统和翼面折叠系统等"特征结构"进行设计。先进舰载战斗机着舰冲击能量是陆基飞机的6倍以上、拦阻带来的水平载荷超过陆基飞机的15倍,因此特征结构的高载荷对强度设计提出了更高的要求。围绕舰载机"特征结构"及"特征载荷",开展了主要的设计工作,包括："特征载荷"计算,即起落架载荷、拦阻载荷和折叠载荷计算;"特征结构"的强度设计及试验验证,包括起落架系统、拦阻系统、翼面折叠系统的动力学仿真计算、静/疲强度分析、折叠翼面的非线性颤振分析以及综合试验验证;"特征载荷"对其他机体结构强度的影响分析,包括着舰载荷对起落架支撑结构强度的影响、拦阻载荷对后机身支撑结构强度的影响、拦阻着舰的全机动力学响应以及着舰载荷与拦阻载荷的共同作用对全机结构强度的影响;体现舰载机"特征结构"强度特点的试验验证方法等。上述研究成果已成功应用于先进舰载战斗机设计中。     

考虑重心位置不确定性的无尾无人机优化设计

飞机的飞行性能与重心(CG)位置密切相关,尤其是后掠式无尾飞机的重心位置对其飞行性能影响更甚,如果重心位置发生变化,升力分布随之改变,进而影响飞机航时。针对这个问题,从气动布局和设计方法两方面,设计了一种航时对重心位置不敏感的无尾无人机(UAV)。气动布局上,提出了利用螺旋桨动力配平纵向力矩的鸥翼(GW)布局,以减小重心位置变化对升阻特性的影响;设计方法上,采用稳健性优化设计(RDO)理论,分析重心位置不确定时的航时低敏感度问题。以一架小型电动无人机为研究对象,建立了无尾无人机稳健性优化设计环境,包括总体设计、代理模型构造以及稳健性优化。分析结果表明:利用螺旋桨动力配平的鸥翼布局使重心可用范围增加了5%;静安定裕度在5%~15%变化时,该布局可以有效提高航时稳健性。采用稳健性优化得到的无人机几何参数,大幅度降低了重心位置对航时的影响,显著提升了满足约束的概率。     

面向机舰适配的舰载飞机起降特性分析

机舰适配性是舰载飞机总体设计的核心内容之一,通常包括性能适配和保障适配两部分,是舰载飞机总体设计特有的阶段;其内涵是指舰载飞机充分、高效利用航母的特性,使用其设备和装置的固有能力。以舰载飞机的使用环境为切入点,定义了有人驾驶陆基飞机改舰载机设计所需考虑的机舰适配的诸多方面;以滑跃起飞/拦阻着舰型舰载机为实例,突出性能适配,对滑跃起飞和拦阻着舰的过程进行物理分解,探求舰机以及环境参数对其性能的影响,建立了相关性能的计算方法,并结合国外典型航母的数据进行了计算分析,定量评估了甲板风对滑跃起飞和拦阻着舰的作用。同时,从保证着舰安全性的角度给出了建议的着舰方式、标准拦阻程序和安全逃逸的最短甲板长度需求。最后,给出了滑跃起飞/拦阻着舰飞机设计的关注点。     

复合材料超临界机翼跨音速颤振实验与数值计算研究

颤振课题是飞机设计过程中常常遇到的一个关键技术问题。以支线客机ARJ21超临界机翼颤振特性研究为背景,在俄罗斯TsAGI的T-106风洞中完成了该复合材料机翼跨音速颤振实验,基于N-S方程和无限插值方法（TFI）生成三维贴体运动网格对超临界机翼跨音速颤振进行了并行计算。结果表明：复合材料的超临界机翼在跨音速区域具有跨音速颤振＂凹坑＂现象;与风洞实验结果相比,有较好的一致性,为使用超临界机翼的运输类飞机跨音速颤振特性预计提供了一定的参考。     

Decision-making of Aircraft Optimum Configuration Utilizing Multidimensional Game Theory

As multi-discipline coupling and components interference often affect the aircraft configuration decision-making and analysis during conceptual design process, this article presents an approach of multidimensional game theory based on aircraft components to deal with this problem. The idea is that the configuration decision-making process is regarded as the game for different disciplines and technologies, and the aircraft components are players. The payoff function with highest total gain means that according to the game protocols and multidimensional theory, the optimal aircraft configuration within the strategy set will be chosen. The decision-making model is applied to conceptual design process of the high altitude long endurance (HALE) unmanned aerial vehicle (UAV) based on the assessment of technological risk. The obtained optimum configuration is quite consistent with the current HALE UAV development trends. Thus, taking into account the coupling and interference factors, the multidimensional gaming model based on aircraft components will be an effective analysis method in the decision-making process of aircraft optimum configuration.     

先进舰载战斗机腐蚀防护控制与日历寿命设计

舰载战斗机是航母编队战斗力的重要组成部分,但由于其复杂恶劣的服役环境,舰载机腐蚀防护控制与日历寿命设计问题已经成为限制海军航空兵战斗力保持与提升的关键难题。腐蚀防护与控制应贯穿舰载机全寿命周期,本文以此为总体思路,首先系统梳理了舰载机在综合设计、材料与涂料选择、制造与使用过程中腐蚀防护与控制的诸多要点与细节。然后针对舰载机日历寿命设计问题,在详述环境谱、加速谱编制原则、编制方法及基本构成的基础上,基于案例阐明腐蚀仿真技术是舰载机日历寿命设计的可靠高效手段,可为相关问题的后续研究提供创新思路。最后指出腐蚀监测是舰载机腐蚀防护控制过程中亟待解决的难题。     

Optimization of fixed aviation support resource station configuration for aircraft carrier based on aircraft dispatch mission scheduling

Before the dispatch of the carrier-based aircraft, a series of pre-flight preparation operations need to be completed on the flight deck. Flight deck fixed aviation support resource station configuration has an important impact on operation efficiency and sortie rate. However, the resource station configuration is determined during the aircraft carrier design phase and is rarely modified as required, which may not be suitable for some pre-flight preparation missions. In order to solve the above defects, the joint optimization of flight deck resource station configuration and aircraft carrier pre-flight preparation scheduling is studied in this paper, which is formulated as a two-tier optimization decision-making framework. An improved variable neighborhood search algorithm with four original neighborhood structures is presented. Dispatch mission experiment and algorithm performance comparison experiment are carried out in the computational experiment section. The correlation between the pre-flight preparation time (makespan) and flight deck cabin occupancy percentage is given, and advantages of the proposed algorithm in solving the mathematical model are verified.     

综合飞行/推力控制系统的智能设计

在介绍正规矩阵参数优化方法和着舰导引控制系统的基础上,为提高舰载飞机的操纵性能,采用智能设计软件IntelDes3．0设计了具有鲁棒性的着舰飞行,推力综合控制系统。基于飞机纵向非线性运动方程的数值仿真结果表明,设计的控制系统对阶跃输入的响应性能良好,鲁棒性较强。     

形态仿生飞行器研制进展及关键技术

从大自然中生物的形态汲取灵感,对优秀的气动外形加以模仿和借鉴,从而获得更好的飞行性能,是形态仿生飞行器设计的基本思路。本文介绍了形态仿生飞行器的研制背景,分析了形态仿生“自上而下”和“自下而上”两种研究过程;按照仿鸟飞行器、仿鱼飞行器和其他仿生飞行器的类别分别介绍了形态仿生飞行器当前发展现状;探究了外形特征的提取方法,参照生物优良特性解决飞行器设计过程中的问题,仿生飞行器气动参数的辨识等关键技术,并对形态仿生飞行器的未来发展趋势进行了归纳总结。本文研究的内容对于形态仿生飞行器的设计具有一定的参考意义。     

Exploring mission planning method for a team of carrier aircraft launching

High-level efficiency and safety are of great significance for improving the fighting capability of an aircraft carrier. One way to enhance efficiency and safety level is to organize the carrier aircraft into combat effectively. This paper studies the mission planning problem for a team of carrier aircraft launching, and a novel distributed mission planning architecture is proposed. The architecture is hierarchical and is comprised of four levels, namely, the input level, the coordination level,the path planning level and the execution level. Realistic constraints in each level of the distributed architecture, such as the vortex flow effect, the crowd effect and the motion of aircraft, are considered in the model. To solve this problem, a distributed path planning algorithm based on the asynchronous planning strategy is developed. The proposed Mission Planning Approach for Carrier Aircraft Launching(MPACAL) is validated using the setups of the Nimitz-class aircraft carrier.Compared to the isolated planning architecture and the centralized planning architecture, the proposed distributed planning architecture has advantages in coordinating the launch tasks not only belonging to the same catapult but also when all different catapults are considered. The proposed MPACAL provides a modeling method for the flight deck operation on aircraft carrier.     

一种小型自主飞行无人机系统集成设计研究

小型自主飞行无人机系统又称为空中机器人,泛指各种能够在空中自由飞行的无人飞行器系统,具有广泛的应用前景.论述了一种5kg小型自主飞行无人机系统的飞行平台的设计与实现、系统选择与集成、图像处理的方法、电磁兼容问题及解决措施等,最终成功地实现了自主飞行,并在"枭龙杯"中国空中机器人大赛上获奖.设计方法在无人机系统试飞和比赛中都得到了验证,证明是有效的.     

一种基于模式寻优的舰载机实时回收方法

为了解决舰载机的回收决策问题，提出一种基于模式寻优的舰载机实时回收方法。通过对典型回收模式的计算分析，寻求最佳的回收模式，解决舰载机回收过程中通用因素带来的回收决策问题。在此基础上，提出一种考虑优先级的时间域区间集算法，解决舰载机回收过程中随机因素带来的回收决策问题，即在既定的回收群体下，寻求最佳的回收序列。仿真结果表明，基于模式寻优的舰载机实时回收方法能够处理复杂多变的回收限制因素，得到合理可行的回收决策方案。     

Application of nonlinear filtering to navigation system designusing passive sensors

The problem of navigation system design for autonomous aircraft landing is addressed. New nonlinear filter structures are introduced to estimate the position and velocity of an aircraft with respect to a possibly moving landing site, such as a naval vessel, based on measurements provided by airborne vision and inertial sensors. By exploring the geometry of the navigation problem, the navigation filter dynamics are cast in the framework of linear parametrically varying systems (LPVs). Using this set-up, filter performance and stability are studied in an H_∞ setting by resorting to the theory of linear matrix inequalities (LMIs). The design of nonlinear, regionally stable filters to meet adequate H_∞ performance measures is thus converted into that of determining the feasibility of a related set of LMIs and finding a solution to them, if it exists. This is done by using-widely available numerical tools that borrow from convex optimization techniques. The mathematical framework that is required for integrated vision/inertial navigation system design is developed and a design example for an air vehicle landing on an aircraft carrier is detailed     

飞机起落架动力学建模及着陆随机响应分析

针对飞机起落架弹性结构特征的动力学建模及其离散结构简化响应分析问题,利用哈密顿变分原理,提出并建立了弹性结构的起落架动力学模型。根据此动力学模型,可自由选择起落架的结构离散数量进行动力学方程的求解和响应分析。以某型飞机着陆过程为研究实例,使用随机模拟方法,通过模拟飞机着陆下沉速度、初始位移和路面不平度,分析了飞机着陆过程起落架的随机响应特征,确定了起落架的实际动力学性能和应力应变特性,为后续起落架的结构参数优化及其疲劳性能分析提供了基础参考依据。     

基于非线性动态逆的舰载机直接升力航迹控制

针对舰载机人工进场着舰精确轨迹控制中飞行员操纵负担重、着舰环境复杂的问题,提出采用非线性动态逆(NDI)先进控制方法设计基于直接升力的舰载机精确着舰轨迹控制律。首先,综合分析了"魔毯"技术的控制策略,从航迹调整和姿态保持的直接升力解耦控制角度出发,设计了两层NDI回路;然后,采用合理的控制分配方法实现直接升力的舵面分配。仿真结果表明,所提出的精确着舰控制方法能够有效实现"魔毯"式航迹操纵。