基于Lagrange方法的航天员舱外活动计算机仿真

在比较各种地面微重力模拟设备的优缺点的基础上，阐述了计算机动态仿真航天员舱外活动(EVA，Extra Vehicular Activity)的必要性。简要的概述了应用计算多刚体系统动力学对EVA进行仿真的步骤。描述了拉格朗日方程在仿真过程中的应用，建立了用于仿真的动力学方程。选取典型的EVA，得出了描述该EVA系统运动的拉格朗日动力学方程。利用反向运动学和反向动力学对该EVA进行了仿真计算，并对结果进行了分析。     

Efficacy of Doppler ultrasound [correction of utrasound] for screening symptoms of decompression sickness during simulated extravehicular activities

Doppler ultrasound is frequently used for monitoring circulating microbubbles during decompression to assess the symptoms of Decompression Sickness (DCS). This analysis was carried out to evaluate its effectiveness for screening symptoms of DCS during simulated extravehicular activities (EVA). The information from various hypobaric chamber studies carried out at the NASA Johnson Space Center, Houston, TX was used in this analysis (n = 516). The circulating microbubbles were detected in the precordial area in 42% (218/516), and symptoms were reported in 16% (81/516) of these exposures. The accuracy of Doppler-detectable bubbles (Spencer grades) on all symptoms of DCS was examined by calculating measures of sensitivity and specificity. The efficacy of Doppler as a screening device was examined by calculating their positive predictive value (PPV) and negative predictive value (NPV). The results of these analyses indicated that the sensitivity of Doppler decreased, and the PPV increased with higher Spencer grades. However, the likelihood of detecting true negative cases (NPV) was consistently higher with all bubble grades. Due to the high false-positive rate and low prior probabilities of the risk of DCS, Doppler was found to be more useful to identify those who did not develop DCS, than to detect positive cases of DCS in the simulated EVA exposures.     

基于事件的EMR遥操作自适应规划与控制方法

提出了基于事件的舱外自由移动机器人 (ExtravehicularMobileRobot,简称EMR)系统在任务空间内的自适应规划与控制方法 ,使系统具有处理突发事件和不确定事件的能力 ,同时提高了系统的自主性和适应能力 ,增强了遥操作的安全性 ,仿真证明了该方法的正确性和有效性。     

Energy utilization rates during shuttle extravehicular activities

The work rates or energy utilization rates during EVA are major factors in sizing of life support systems. These rates also provide a measure of ease of EVA and its cost in crew fatigue. From the first Shuttle EVA on the STS-6 mission in 1983, we have conducted 59 man-EVA and 341 man-hours of EVA. Energy utilization rates have been measured on each of these EVA. Metabolic rate was measured during each EVA using oxygen utilization corrected for suit leakage. From 1981–1987, these data were available for average data over the EVA or over large segments of the EVA. Since 1987, EVA oxygen utilization data were available at 2-minute intervals. The average metabolic rate on Shuttle EVA (194 kcal/hr.) has been significantly lower than metabolic rates during Apollo and Skylab missions. Peak rates have been below design levels, infrequent, and of short duration. The data suggest that the energy cost of tasks may be inversely related to the degree of training for the task. The data provide insight on the safety margins provided by life support designs and on the energy cost of Station construction EVA.     

国外宇航员舱外机动装置发展综述

综述了“双子星座”和航天飞机等空间飞行器上的宇航员舱外机动装置（ＭＭＵ）的发展历程、技术特点及主要技术参数，并对其优缺点进行了分析。介绍了国外对空间站上的ＭＭＵ的设想。     

舱外航天服热控系统仿真

针对人体穿着航天服处于过热状态下的散热问题，在分别建立人体热调节系统、金属氢化物冷源和液冷服数学模型的基础上，将3个模型进行结合，对舱外航天服热控系统在5．5h的时间轴上进行综合的仿真计算，求出人体各节段的温度分布情况，液冷服的入口及出口水温，金属氢化物冷源的出口水温等参数，分析航天员的热舒适性，对航天服热控系统的设计有一定的指导作用，并为今后进一步的研究打下了基础．     

The extravehicular mobility unit: A review of environment, requirements, and design changes in the US spacesuit

Requirements are rarely static, and are ever more likely to evolve as the development time of a system stretches out and its service life increases. In this paper, we discuss the evolution of requirements for the US spacesuit, the extravehicular mobility unit (EMU), as a case study to highlight the need for flexibility in system design. We explore one fundamental environmental change, using the Space Shuttle EMU aboard the International Space Station, and the resulting EMU requirement and design changes. The EMU, like other complex systems, faces considerable uncertainty during its service life. Changes in the technical, political, or economic environment cause changes in requirements, which in turn necessitate design modifications or upgrades. We make the case that flexibility is a key attribute that needs to be embedded in the design of long-lived, complex systems to enable them to efficiently meet the inevitability of changing requirements after they have been fielded.     

基于约束运动理论的航天员舱外救生中的姿态运动控制

航天员舱外救生或作业时相对母体航天器经常要进行大角度姿态机动或姿态保持,利 用欧拉四元数描述姿态无奇异性且冗余度小。然而航天员舱外调姿时通常含有一定的约束或 是沿着某种预定轨迹,而且欧拉四元数在计算过程中可能发散。基于Udwadia和Kalaba 提出的约束运动理论,分析了航天员和航天器的相对姿态的描述方法,直接用四元数对航天 员的姿态进行动力学建模,将四元数2范数为1的约束加入到动力学方程里。利用该约束运动 理论推导和仿真了航天员姿态欧拉角奇异时的姿态跟踪控制方法。该控制方法对航天员肢体 变化引起的转动惯量等参数的改变具有鲁棒性,能通过平衡解稳定参数的选取方便地对控制 系统的性能进行调节,且计算量小。
     

航天员舱外相对航天器运动轨迹摄动研究

用轨道根数描述载人航天器运动,在其轨道坐标系(LVLH)中,建立了含地球J2项引力和大气阻力摄动加速度的航天员质心相对航天器的运动模型。在参考轨道存在小偏心率时,对基于圆参考轨道假设推导的航天器编队飞行的线性时变系统状态矩阵进行了修正。仿真结果表明:对偏心率为0.002的航天器轨道,修正后模型所得航天员相对轨迹摄动量在离舱300 s后达到0.8%,是修正前模型的5倍,但计算量增加不超过5%,更适于航天员舱外飞行和近距离编队飞行建模。     

多孔板水升华器试验研究

探索了多孔板的制造方法,设计了水结器试验单元件和试验装置;对不同的多孔板升华器进行了试验研究,试验重点研究了热流体入口温度和流量、多孔板物理参数、给水室压力及升华器放置情况对升华器性能的影响。试验结果证明文章提出的升华器基本的设计概念是可行的,并给出了关于水升华器进一步设计的一些有益的结论。