民机客舱布局工效学量化设计模型

为提升客舱布局设计效率及面向民机客舱快速仿真设计系统提供技术支撑,提出了一种民机客舱布局量化设计模型。该模型面向工效学设计需求,以座椅排距、座椅排数、各级客舱舱段长度等作为设计变量,构造了舒适性、安全性、经济性三类目标函数,实现了客舱边界限制、人机空间耦合关系、适航安全性要求等约束条件的量化描述。分别以双通道宽体干线客机、单通道窄体干线客机和支线客机为应用算例,对所提模型的可用性进行了计算验证。结果表明:所提模型可适用于多种机型的客舱布局设计,能够提供多个满足舒适性、安全性、经济性等多样化工效学设计指标的量化设计方案,并可给出各类指标进一步的优化途径。所提模型在一定程度上实现了民机客舱布局量化设计,为概念设计阶段客舱布局快速设计和多方案比较提供了一种新的方法,同时也可作为航空公司客舱布局选型的定量化辅助决策工具。      

Large constellations assessment and optimization in LEO space debris environment

Recent plans for large constellations in Low-Earth Orbit have opened the debate on both their vulnerability and their influence on the already hazardous space debris environment. In fact, given that large constellations normally employ satellites of small size, there might be situations in which cm-size debris could have enough energy to cause fragmentation of a significant part of these spacecraft upon impact, while smaller debris could affect the functionalities of critical subsystems, even compromising the success of disposal operations planned at end-of-life. In this context, this paper investigates: (1) collisions with large objects that could initiate the fragmentation of a significant part of the satellite, and (2) impacts with small debris that might perforate the spacecraft hull thus causing relevant performance/functionality degradation. These two points are merged in a simple statistical tool for risk assessment, which analyses the effects of the main parameters of the constellations on its vulnerability (i.e. operational life, number of satellites, spacecraft cross section, satellites reliability). In more details, the tool relates impact probability (for both small and large debris) to the ballistic response of spacecraft structures and protections, defining the critical configurations that might compromise the expected disposal operations. This method requires a limited knowledge of the spacecraft internal layout, as it is based on a statistical analysis of impact damage instead of a complete evaluation of the vulnerability of each subsystem. In parallel, non-debris related failures are also investigated and statistic models of spacecraft reliability characteristic are proposed. Among the results, it is shown that reducing the lifetime of individual satellites in a constellation might improve the success rate of post-mission disposal, thanks to the reduction of the spacecraft exposure to the space environment with the consequential degradation of its performance. On the other hand, reducing the lifetime would seriously affect the debris environment: the increase in traffic in the most crowded altitudes would be not counterbalanced by the higher post mission disposal success rate, causing an overall increase of the total number of uncontrolled resident objects.     

Micro-meteoroids and space debris impact risk assessment for the ConeXpress satellite using ESABASE2/Debris

Micro-meteoroid and space debris impact risk assessments are performed to investigate the risk from hypervelocity impacts to sensitive spacecraft sub-systems. For these analyses, ESA’s impact risk assessment tool ESABASE2/Debris is used. This software tool combines micro-particle environment models, damage equations for different shielding designs and satellite geometry models to perform a detailed 3D micro-particle impact risk assessment. This paper concentrates on the impact risk for exposed pressurized tanks. Pressure vessels are especially susceptible to hypervelocity impacts when no protection is available from the satellite itself. Even small particles in the mm size range can lead to a fatal burst or rupture of a tank when impacting with a typical collision velocity of 10–20 km/s. For any space mission it has to be assured that the impact risk is properly considered and kept within acceptable limits. The ConeXpress satellite mission is analysed as example. ConeXpress is a planned service spacecraft, intended to extend the lifetime of telecommunication spacecraft in the geostationary orbit. The unprotected tanks of ConeXpress are identified as having a high failure risk from hypervelocity impacts, mainly caused by micro-meteoroids. Options are studied to enhance the impact protection. It is demonstrated that even a thin additional protective layer spaced several cm from the tank would act as part of a double wall (Whipple) shield and greatly reduce the impact risk. In case of ConeXpress with 12 years mission duration the risk of impact related failure of a tank can be reduced from almost 39% for an unprotected tank facing in flight direction to below 0.1% for a tank protected by a properly designed Whipple shield.     

翼身融合布局客机客舱布置快速生成原型系统

翼身融合布局（BWB）客机的客舱布置方案在很大程度上决定了其气动外形，筛选出一种合理的客舱布置方案是BWB客机概念设计的一项重要任务。为了提高BWB客机客舱布置设计的效率，应用基于知识工程（KBE）的方法，将BWB客机客舱布置的知识和规范融入在客舱布置几何模型创建过程中，开发出了一个BWB客机客舱布置快速生成的原型系统。分别以300座和400座BWB客机为例，验证该原型系统的有效性。结果表明，只需输入客舱布置设计要求和主要参数，该原型系统即可自动地生成客舱布置方案。所开发的原型系统为BWB客机客舱设计提供了一种快速的途径。      

基于高斯伪谱法的碰撞规避策略研究

为保证在轨卫星运行安全,对于碰撞概率较高的空间交会情况需要进行规避机动,防止在轨卫星与空间碎片碰撞.选取连续推力策略进行规避机动,将空间碰撞规避过程转化为满足复杂约束的最优控制问题,采用高斯伪谱法对最优控制律进行求解,求解结果满足相应约束.研究结果为航天器有效规避空间碰撞威胁提供了有力支持.     

航天器微流星体及空间碎片环境与风险分析

微流星体及空间碎片的高速撞击威胁着长寿命、大尺寸航天器的安全运行 ,导致其严重的损伤和灾难性的失效。文章对低地球轨道微流星体及空间碎片环境进行了分析 ,给出了微流星体及空间碎片对航天器威胁方向的确定方法 ,得到了空间碎片撞击航天器相对撞击角的概率分布以及地球对微流星体遮挡的影响。编制了风险分析软件 ,以采用单防护屏防护结构的柱状低地球轨道航天器为例进行风险分析。     

The impact of alternative mission models on the future orbital debris environment

In reviewing discussions of future directions for space activity, it becomes obvious that there are a large number of groups formulating a wide diversity of plans for the future use of space. These plan alternatives are being made to account for user needs, technology development constraints, economic constraints, and launch support, and each of the plans will have direct or indirect effects on the orbital debris environment in terms of mass to orbit, deposition of operational debris, and control of accidental breakups. Thus it is important to develop the ability to project future debris states for a range of possible space traffic scenarios. The impact that these possible traffic environments would have on space operations forms the basis for studies of alternative options for the usage of space. In this paper, the effects on the orbital debris environment of a base-line mission model and two alternatives are investigated, using a numerical debris environment simulation code under development at JSC.     

卫星规避方案量化分析方法研究

空间碎片数量日益增多,为保护在轨卫星的运行安全,需要针对碎片碰撞制定规避方案,用来规避碰撞风险.本文在调研国外卫星规避机动流程的基础上,分别研究了卫星规避相关的轨道机动方式、轨道预报模型以及交会风险计算模型,建立了卫星规避方案量化分析方法,为规避方案的选择提供参考.     

MONITORING OF ENERGETIC PARTICLE ENVIRONMENT INSIDE THE CHINA-BRAZIL EARTH RESOURCE SATELLITE

On 14 October 1999, the Chinese-Brazil earth resource satellite (CBERS-1) was launched in China. On board of the satellite there was an instrument designed at Peking University to detect the energetic particle radiation inside the satellite so the radiation fluxes of energetic particles in the cabin can be monitored continuously. Inside a satellite cabin, radiation environment consists of ether penetrated energetic particles or secondary radiation from satellite materials due to the interactions with primary cosmic rays.Purpose of the detectors are twofold, to monitor the particle radiation in the cabin and also to study the space radiation environment The data can be used to study the radiation environment and their effects on the electronics inside the satelhte cabin. On the other hand, the data are useful in study of geo-space energetic particle events such as solar proton events, particle precipitation and variations of the radiation belt since there should be some correlation between the radiation situation inside and outside the satellite.The instrument consists of two semi-conductor detectors for protons and electrons respectively. Each detector has two channels of energy ranges. They are 0.5-2MeV and ≥2MeV for electrons and 5-30MeV and 30-60MeV for protons. Counting rate for all channels are up to 104/(cm2@s)and power consumption is about 2.5 W. There are also the additional functions of CMOS TID (total integrated dose) effect and direct SEU monitoring. The data of CBMC was first sent back on Oct. 17 1999 and it's almost three years from then on. The detector has been working normally and the quality of data is good.The preliminary results of data analysis of CBMC not only reveal the effects of polar particle precipitation and radiation belt on radiation environment inside a satellite, but also show some important features of the geo-space energetic particle radiation.As one of the most important parameters of space weather, the energetic charged particles have great influences on space activities and ground tech nology. CBMC is perhaps the first long-term on-board special equipment to monitor the energetic particle radiation environment inside the satellite and the data it accnmulated are very useful in both satellite designing and space research.     

Chebyshev不等式在空间碎片碰撞概率置信度中的应用

空间碎片的碰撞预警与规避能有效避免碰撞事件的发生.碰撞概率是碰撞预警的主要判据,也是航天器规避机动决策的主要依据.由于计算碰撞概率的各相关参数带有误差,导致计算得到的碰撞概率值并不准确,难以做出规避机动决策,因此评估碰撞概率值的可信程度是亟需解决的问题.本文给出了一种碰撞概率置信度的计算方法,利用各影响参数的标准差,通过误差传递的方法计算碰撞概率的标准差,结合单边Chebyshev不等式,给出碰撞概率值大于10^-4阈值时的置信度,并结合实际案例进行了分析.     

卫星天线复合材料框架的铺层优化设计

为了改善卫星天线复合材料框架的结构动力学性能,提出了一种针对卫星天线框架复合材料铺层的两阶段优化设计方法。阶段Ⅰ以各铺层的角度为设计变量进行铺层顺序优化,框架基频的最大化为优化目标,铺层数的最大值为约束条件。其中设计变量用一种多进制码来表示,并将多进制码映射为连续变量,应用粒子群优化(PSO)算法对阶段Ⅰ优化模型进行求解。在阶段Ⅰ优化结果的基础上,阶段Ⅱ主要是优化复合材料的层数,以基频最大化与质量最小化为优化目标建立多目标拓扑优化模型,应用第2代非劣排序遗传算法(NSGA-Ⅱ)进行求解。为了验证该方法的有效性,对某大型卫星天线复合材料框架进行优化设计,结果表明:该方法能有效地减小天线板复合材料框架的质量,并提高基频。     

Prospects of de-tumbling large space debris using a two-satellite electromagnetic formation

Capturing large space debris with complex rotational motion is extremely challenging. A de-tumbling phase before capturing may be necessary to reduce the risk of collision with debris. This paper proposes a new noncontact de-tumbling method using a two-satellite electromagnetic formation, in which two small electromagnetic satellites, each having a high-temperature superconducting coil, generate control torques to reduce the rotation rate of debris prior to making any physical contact. The electromagnetic interaction of the target-satellite system is analyzed. A relative translational dynamics of the target–satellite system and the attitude dynamics of the target are established. Simulation results show that the proposed method effectively eliminates the rotational motion of the target. It can be safely concluded that the noncontact method for de-tumbling space debris using a two-satellite electromagnetic formation is feasible and potentially applicable to on-orbit capture.     

量子科学实验卫星密钥分发实验任务规划

针对量子科学实验卫星密钥分发实验任务规划约束条件多以及时效性要求高的特点,基于对密钥分发实验过程及约束分析,建立了约束满足规划模型.以完成时限最短为优化目标,综合考虑任务规划所需光学及数传站资源分配,利用深度优先搜索算法对模型进行求解,解决了实验过程中多要素紧耦合、强时间约束的难题.仿真分析结果表明,所提出的模型及算法有效,能够满足量子科学实验卫星密钥分发实验星地交互的需求.     

基于火灾疏散安全指数的飞机客舱防火设计

为研究飞机客舱设计对防火性能的影响,首次提出火灾疏散安全指数(FESI) 的概念.利用PyroSim及Pathfinder仿真软件对飞机客舱的火灾场景和疏散过程进行模拟,确定不同客舱内表面积、出口宽度和高度及搭载人数下出口的FESI,分析以上设计因素对客舱火灾疏散能力的影响.使用BP神经网络算法确定几种窄体飞机在确保火灾疏散安全情况下的最大搭载人数.并以B737-800飞机为例对其疏散方案进行优化,模拟结果表明:客舱的内部表面积、舱门尺寸及座位数都是显著影响客舱防火性能的设计因素,典型布置下的B737-800飞机最大承载人数为154人,在疏散方案优化后可增加至175人.所提出的FESI不仅可对现有飞机的防火性能进行评估,优化客舱布局及人员疏散方案,还可为国产大型飞机客舱防火设计提供依据,同时为其他领域的消防研究提供参考.      

Active detumbling technology for noncooperative space target with energy dissipation

Space debris is generally a kind of tumbling noncooperative space target which poses a serious threat to human space activities. In active debris removal (ADR) missions, capturing a space target directly may cause damage to space manipulator and chaser satellite, so it is a feasible strategy to reduce the angular velocity of space target to an acceptable range in the pre-capture phase. In this paper, an active detumbling technology for a free-floating tumbling space target with energy dissipation is studied, and an effective detumbling method utilizing intermittent contact impact between the space target and despin mechanism is proposed. First, the dynamic model of the space target is set up by the Jourdain’s velocity variation principle. Then, a contact model between the space target and despin mechanism is established based on the Hertz contact theory and the method of computer graphics. Finally, the detumbling method is validated by numerical simulations. Simulation results show that our method can reduce the angular velocity of the space target effectively without causing large nutation.     

质量特性对航天器火工冲击传递影响仿真分析

航天器火工冲击环境复杂,冲击载荷的瞬态、高度非线性等特点,使得冲击响应的准确预示具有一定难度。卫星舱板上分布大量单机设备,其质量特性成为影响火工冲击传递的关键因素。根据火工冲击传递机理,建立了卫星舱板与单机设备的冲击有限元简化模型,计算了舱板上的火工冲击响应。通过与试验数据的对比,误差控制在±3.5 dB内,验证了有限元建模的合理性。以此为基础,研究了火工冲击传递特性,为火工冲击响应预示及卫星舱板布局设计提供了参考。     

空间站在轨维修操作复杂度评价及试验验证

在轨维修是维持空间站在太空特殊环境安全运行的必要手段,太空特殊环境和空间站结构特点决定了空间站在轨维修任务的复杂度。在轨维修操作复杂度关系到空间站维修方案的优化、维修计划的制定、货运飞船的安排、航天员培训和空间站可维修性设计。然而,针对空间站在轨维修操作复杂度的评价研究较少。因此,提出了空间站在轨维修操作复杂度的概念,考虑了维修固有复杂度和外部影响因子2个方面,基于信息熵理论建立了复杂度评估模型。固有复杂度包括维修操作逻辑、维修动作规模、维修人机界面和维修操作知识,并借助信息熵完成以上4个方面的量化;外部影响因子包括操作空间、有无维修工具、时间压力、视觉遮挡和航天服影响,并利用分级打分制予以量化。为验证模型的有效性,基于地面模拟舱开展了12类产品维修验证试验,采集了受试者的维修动作及时间。实验数据分析表明,提出的模型能够较好地预测产品的维修耗时（相关系数为0.82）,并能较为合理地对空间站在轨维修操作复杂度进行量化分级。为在轨维修的开展、维修方案的评价、航天员乘组训练与安排和空间站设计更改提供方法指导。      

非合作失效航天器绳系拖曳系统研究

空间碎片的不断增加给人类航天活动的开展和在轨资产的安全造成严重威胁。在已经提出的多种空间碎片主动清除方式中,绳系拖曳（tethered space tug,TST）系统因有较好的应用前景而受到广泛关注。部分失效航天器因星上器件损坏且姿态控制系统异常,始终将姿态维持在某一特定指向,针对此类具有典型的非合作特征的大型空间碎片,开展绳系拖曳动力学与控制研究。将拖船和目标均视作刚体,用牛顿法建立了TST系统的动力学模型;根据目标姿态稳定方式分为自旋稳定和三轴稳定两种情况,开展了绳系拖曳动力学分析与控制设计,并考察了系绳在失效航天器表面连接点位置对系统稳定状态的影响。仿真结果表明,拖船和失效航天器会在系绳连接下表现出抗衡特点,最终系统会稳定在不同的均衡状态附近。此研究为安全清除尚有残余姿态控制能力的失效航天器中相关拖曳动力学与控制问题提供了参考。     

空间碎片的空间密度算法研究

由于空间碎片的影响, 空间环境日益恶劣,有必要建立空间碎片环境工程模型对空间碎片撞击航天器进行风险评估.本文研究了空间碎片环境模型中的重要环节, 即碎片的空间密度问题,在统计理论与椭圆轨道理论基础上,分析及推导了空间碎片在空间中的分布状况及空间密度,并得出了碎片空间密度的空间坐标函数解析表达式.同时对引入假设条件的合理性进行了讨论,并利用双行元数据对结论进行了验证, 利用本文方法得出的结果与双行元数据吻合.