Prioritized Spatial Updating in the Intrinsic Frame of Reference

In order to maintain valid situation awareness, people need to update the spatial representations of their surroundings as objects, including themselves, move. The present study investigates the properties of spatial updating in the intrinsic frame of reference, where spatial relations are represented with respect to an external object (other than the viewer self) with an intrinsic reference direction. Three experiments were conducted using a task of direction pointing. It was found that given a relatively stable intrinsic reference direction, responses to a small number of salient objects were faster than responses to non-salient objects (Experiment 1 and Experiment 3). The salience effect disappeared when the intrinsic reference direction was no longer stable (Experiment 2). Furthermore, all three experiments revealed a type of orientation dependence similar to that found in egocentric spatial updating. Our results indicate that spatial updating in the intrinsic reference system can be easy only if a fixed reference direction is maintained and the number of objects that need to be tracked is limited.     

Omicron space habitat—research stage II

The design presented in this paper is in response to the revolution in private space activities, the increasing public interest in commercial flights to space and the utilization of structures such as space hotels or private orbital habitats. The baseline for the Omicron design concept is the Russian Salyut derived space station module. Salyut was the first space station to orbit the Earth. Its unique design and technical features were what made the development of space stations Salyut 1–7, MIR and the International Space Station (ISS) Zwezda service module possible. Due to its versatility and the reliable operating launch vehicle Proton, this space module series has the potential to be adapted for space hotel development. This paper proposes a conceptual design of the space habitat called Omicron, with particular focus on interior design for the microgravity environment. The Omicron concepts address the needs of space tourism with a strong emphasis on the safety and comfort of the spaceflight participants. The Omicron habitat supports three inhabitants in nominal conditions (e.g., two passengers and one astronaut). The habitat provides a flexible interior, facilities and spaces dynamically transforming in order to accommodate various types of activities, which will be performed in an organically formed interior supporting spatial orientation and movement in microgravity. The future development potential of Omicron is also considered. The baseline version is composed solely of one rigid module with an inverted cupola for observations. An alternative version offers more space using an inflatable structure. Finally, a combination of multiple Omicron modules enables the creation of a larger orbital habitat. The Omicron's subsystems support a few days visit by trained passengers. The transport to the habitat would be provided e.g., by the Soyuz TMA spacecraft carried by the Soyuz launch vehicle in the early stage of Omicron's development, before a fully reusable spacecraft would be available.     

Egocentric frames of reference used for the retrieval of survey knowledge learned by map and navigation

Two experiments are reported that use a ``point-to-unseen-targets' task to study the role of egocentric reference frames in the retrieval of survey knowledge learned from either studying a map or navigating an environment. In Experiment 1, performance was generally consistent with the hypothesis that map knowledge is retrieved using a frame of reference centered on the eye, characterized by (a) a fixed orientation in a ``frontal representational plane' and (b) equal access to spatial relations both in front of, or above, and behind, or below, a right-left retrieval axis. The results of Experiment 2 were consistent with the hypothesis that environment knowledge is retrieved within a frame of reference centered on the body, characterized by (a) flexible orientation within a ``transverse representational plane' and (b) privileged access to spatial relations located in front of the right-left retrieval axis in representational space. Both types of knowledge function as if they preserve information about the Euclidean angles connecting elements in physical space.     

Selecting a reference frame

Reference frames are representations that parse space. In the case of spatial terms, reference frames mediate the mapping of linguistic expressions onto spatial configurations of objects. In the sentence ``The fly is above the cat,' ``above' is defined with respect to a reference frame that is imposed on the cat. Different types of reference frames can be used to define spatial terms, each based on a different source of information. For example, gravity, the orientation of objects in the scene or the orientation of the viewer can all be used to set the orientation of a reference frame. When these reference frames disagree (because the viewer is reclining or because the objects in the scene are overturned), there are competing definitions for the spatial term, resulting in the need for reference frame selection. The purpose of this paper is to review a line of research that examines reference frame selection in the context of spatial language. This work shows that all reference frames are initially active and assign a direction to a spatial term. Moreover, this activation is automatic, and is followed by the selection of a single reference frame, with selection accompanied by inhibition of the non-selected frames. Parallels between reference frame selection in language and in perception and attention are discussed.     

Path Integration During a Neighborhood Walk

In three experiments, we contrast two accounts of path integration processes that track direction and distance of movement. Moment-to-moment updating involves the continuous sensing of motion; automatic calculations constantly produce an estimate of position and orientation of self to an anchor point for travel. In contrast, configural updating can be accomplished using episodic memories; a representation of the traveled path is periodically revised and the bearing to the origin of a route can be estimated by connecting the endpoint of the current leg to the starting point of the first leg. Experiments 1 and 3 indicate that people encode the number and direction of turns but have difficulty configuring more gradually curved legs. In Experiment 2, we find that blindfolded people show better than chance performance in estimating the origin of outdoor routes when they are unexpectedly asked to point. It appears that, in addition to episodic memories that allow configural updating, we have available a moment-to-moment representation of our position and heading based on the cues that accompany self-movement.     

一种空间机械臂构造模块的研制

提出了通用二自由度空间模块（TODOM）的概念，并以通用TODOM作为空间机械臂的构造模块。TO—DOM由两个旋转模块及一个连接模块共三个基本模块组成。根据空间机械臂的具体构型需要，将TODOM的三个基本模块之间的机械接口进行专门设计，即可配置成确定构型的二自由度关节。由这样数个不同构型的二自由度关节可以组装出具有偶数个自由度的空间机器臂。采用一体化概念设计的TODOM减小了关节的质量与体积，提高了系统的可靠性。通过对由TODOM构成的一套二自由度关节进行的试验初步验证了TODOM设计概念的合理性及可行性。     

Three dimensional spatial memory and learning in real and virtual environments

Human orientation and spatial cognition partlydepends on our ability to remember sets ofvisual landmarks and imagine their relationshipto us from a different viewpoint. We normallymake large body rotations only about a singleaxis which is aligned with gravity. However,astronauts who try to recognize environmentsrotated in 3 dimensions report that theirterrestrial ability to imagine the relativeorientation of remembered landmarks does noteasily generalize. The ability of humansubjects to learn to mentally rotate a simplearray of six objects around them was studied in1-G laboratory experiments. Subjects weretested in a cubic chamber (n = 73) and aequivalent virtual environment (n = 24),analogous to the interior of a space stationnode module. A picture of an object waspresented at the center of each wall. Subjectshad to memorize the spatial relationships amongthe six objects and learn to predict thedirection to a specific object if their bodywere in a specified 3D orientation. Percentcorrect learning curves and response times weremeasured. Most subjects achieved high accuracyfrom a given viewpoint within 20 trials,regardless of roll orientation, and learned asecond view direction with equal or greaterease. Performance of the subject group thatused a head mounted display/head tracker wasqualitatively similar to that of the secondgroup tested in a physical node simulator. Body position with respect to gravity had asignificant but minor effect on performance ofeach group, suggesting that results may alsoapply to weightless situations. A correlationwas found between task performance measures andconventional paper-and-pencil tests of fieldindependence and 2&3 dimensional figurerotation ability.     

小推力下卫星编队的非自然构型设计与控制

使用小推力控制可以得到许多独特的非自然卫星编队构型,主从星相对位置不变和从星圆形匀速绕飞构型是两类最典型的构型,建立了这两类编队构型的编队参数(主从星距离、空间方位和绕飞速度)与一天内燃料消耗的关系。进一步考虑存在初始误差时控制律的设计,指出PD控制律能够维持小初始误差编队构型,改进的PD控制律能够维持中等初始误差编队构型,而PD控制律和直接法相结合的混合控制律能够维持大初始误差编队构型,仿真结果验证了所设计控制律的有效性。     

Changing structure of the Soviet space programme

Political and economic changes in the USSR are having a dramatic impact on the nature and direction of the Soviet space programme. This article describes the main elements of what can now be seen as a sprawling and fractured bureaucracy. Some voices within the USSR are calling for the creation of some kind of national space agency, but the forces making for further fragmentation seem stronger. Whatever the eventual outcome, new opportunities for international commercial contact are likely to arise.     

Influence of anisotropic fluctuations of the ionosphere plasma density on deep radio sounding by a ultra wide band radar with synthesized aperture

The problem of deep sounding of planet interior using ultra wide band radar with synthesized aperture is considered for the case when anisotropic fluctuations of the ionosphere plasma density take place. Modeling is performed for a number of values of the medium and radar characteristic parameters. The degree of influence of mutual orientation of the anisotropy direction of ionospheric fluctuations and of the spacecraft flight trajectory is estimated. It is demonstrated that widening of radar pulses is determined by characteristic spatial scale of ionosphere plasma disturbances in the transverse direction relative to the spacecraft flight trajectory. On the other hand, attenuation of the peak power of the pulses is shown to be determined basically by the longitudinal scale of disturbance correlations.     

Design problems of large space mirror radiotelescopes

Large space antennas can solve some actual problems of fundamental and applied investigations. Mirror antennas of large diameters (up to tens or hundreds of meters) are designed using an automatically deployed truss frame as a base onto which the radioreflecting surface is pulled (long-wave version) or precisely controllable panels are mounted (shortwave version). The reasons are discussed why antennas of millimeter range can be promptly developed. The factors are considered that influence on the resultant precision of the reflecting surface of the space antenna: technological errors in the process of frame manufacturing; technological errors during manufacturing of the reflecting surface; deformations due to thermal or force effects. To operate in the millimeter wavelength range, it is required to design antennas with automatic control of the reflecting surface. The analysis of the mathematical model of a modular mirror leads to the conclusion about the basic possibility of its adjustment.     

Intelligent spacecraft module

The paper presents the development of an on-going research project that focuses on a human-centered design approach to habitable spacecraft modules. It focuses on the technical requirements and proposes approaches on how to achieve a spatial arrangement of the interior that addresses sufficiently the functional, physiological and psychosocial needs of the people living and working in such confined spaces that entail long-term environmental threats to human health and performance. Since the research perspective examines the issue from a qualitative point of view, it is based on establishing specific relationships between the built environment and its users, targeting people?s bodily and psychological comfort as a measure toward a successful mission. This research has two basic branches, one examining the context of the system?s operation and behavior and the other in the direction of identifying, experimenting and formulating the environment that successfully performs according to the desired context. The latter aspect is researched upon the construction of a scaled-model on which we run series of tests to identify the materiality, the geometry and the electronic infrastructure required. Guided by the principles of sensponsive architecture, the ISM research project explores the application of the necessary spatial arrangement and behavior for a user-centered, functional interior where the appropriate intelligent systems are based upon the existing mechanical and chemical support ones featured on space today, and especially on the ISS. The problem is set according to the characteristics presented at the Mars500 project, regarding the living quarters of six crew-members, along with their hygiene, leisure and eating areas. Transformable design techniques introduce spatial economy, adjustable zoning and increased efficiency within the interior, securing at the same time precise spatial orientation and character at any given time. The sensponsive configuration is programmed to exhibit behavior in direct relation to human activity. It is based upon two active systems, the Activity Evaluation System (AES) and the Response System (RS), with combined action that is always open to the control of the user. The AES monitors the daily schedule of the astronauts in order to find patterns of activity, understand the context of actions and moreover to assess the psychological condition of the crew-members. If it finds cause for intervention, AES will give way to the RS which employs smart materials, controllers and actuators in order to perform required changes in the environmental factors, both spatial (volume and surface) and ambient (audio, visual, olfactory, and haptic), and induce a desirable spatial and/or psychological condition that is beneficial for the astronauts? comfort and well being.     

基于轨迹规划的自由漂浮空间机器人抓取运动物体的研究

针对空间机器人非完整性和冗余性，对笛卡空间下的轨迹规划问题进行了研究。在此基础上，分析了空间机器人抓取运动物体的策略，提出了基于轨迹规划的空间机器人路径规划方法，并以三自由度空间机器人为例，对空间机器人抓取运动目标体的问题进行了研究，该方法是开环控制方法，但由于在进行轨迹跟踪过程中，误差不累积，得到的实际曲线与理论曲线相近，误差达到了规定的范围。     

Effects of eccentricity of the reference orbit on multi-tethered satellite formations

The paper discusses the relevance of eccentric reference orbits on the dynamics of a tethered formation, when a massive cable model is included in the analysis of a multi-tethered satellite formation. The formations examined in this study are hub-and-spoke (HAS) and closed-hub-and-spoke (CHAS) configurations for in-plane and Earth-facing spin planes. Stability of the formations is studied by means of numerical simulation, together with the evaluation of the effects of eccentricity on tether elongation, agents relative position, and formation orientation and shape.     

The acquisition of survey knowledge for local and global landmark configurations under time pressure

The influence of stress states on cognition is widely recognized. However, the manner in which stress affects survey knowledge acquisition is still unresolved. For the present study, we investigated whether survey knowledge acquisition during a stressful task (i.e., under time pressure) is more accurate for the mental representation of global or local landmarks. Participants navigated through virtual cities with a navigation aid and explicit learning instructions for different landmark configurations. Participants’ judgments of relative direction (JRDs) suggest that global landmark configurations were not represented more accurately than local landmark configurations and that survey knowledge acquisition was not impaired under time pressure. In contrast to prior findings, our results indicate the limitations of the utility of global landmarks for spatial knowledge acquisition.     

一种航天器磁特征全息成像方法

为准确描述和评估航天器的磁特性,建立航天器网格化磁模型,提出航天器磁场信息成像方法。利用立体阵列扫描系统,对航天器测量面的磁场信息进行采集和计算,联合磁梯度张量的模量极值和欧拉反演法确定其内部磁源的水平位置和深度,实现航天器内部、探测面和空间磁信息的可视化分析和展示。航天器模型（格距10 cm）三点磁源试验和计算结果显示,该方法对内部磁源单方向定位偏差小于0.05 m,单方向磁矩偏差小于0.02 A?m2;空间磁场强度和磁矩误差均小于5%。该方法为快速获取类长方体形航天器的磁信息提供了一种新的工程实践手段。     

Onboard sensor orientation analysis with kriging method

We propose in this paper a method to analyse the efficiency of the direction pointed by an infrared sensor dedicated to forest fire detection on board of a space vehicle. The objective is to use these sensors to detect forest fires on a defined territory with a specified probability. One way to verify that the system stands this specification is to test each possible configuration (pointing direction of the sensor and number of space vehicles) and estimate the corresponding probability of forest fire detection. However, when the coverage territory is wide or when the number of vehicles is important, it is hardly possible to simulate every configuration in a reasonable amount of time. We propose to use kriging method for the prediction of forest fire detection probability for all possible configurations.     

CCSDS统一空间数据链路协议应用分析

针对TM、TC、AOS、Proximity-1四种空间数据链路协议的应用局限性，对CCSDS（国际空间数据系统咨询委员会）提出的统一空间数据链路协议（Unified Space Data Link Protocol， USLP）规范进行分析，介绍了USLP传输帧主导头和数据域中各个字段的设计驱动，以及与其他空间数据链路协议的差异。对于服务数据单元信道复用传输需求，梳理了物理信道、主信道、虚拟信道、多路复用访问信道的服务类型，明确了数据传输服务、信道复用、信道标识、服务数据单元之间的关联关系。以遥测遥控数据空间链路传输为例，分析了USLP的适用性和推荐设置。     

固体火箭发动机虚拟样机集成设计环境

为支持固体火箭发动机基于虚拟样机的设计技术,提出了固体火箭发动机虚拟样机集成设计环境软件架构。介绍了支持固体火箭发动机虚拟样机的集成设计环境(SRM IDE),该环境集成了发动机设计常用软件和商用软件,以项目管理为中心,采用分布式体系结构,支持分布在异地的设计人员协同构建发动机虚拟原型和协同仿真,以及发动机设计过程中文档、数据、流程、产品结构及资源等的管理。     

Orientation of Sharp Fronts of the Solar Wind Plasma

Based on simultaneous observations performed by several spacecraft, we evaluate the orientation of sharp (with a duration of a few minutes) and large (tens and hundreds percent of the mean value) fronts of the solar wind plasma (changes in the ion flux and ram pressure). The orientation of the fronts is determined with respect to the Sun–Earth line and to two planes in space for several tens of the largest (in amplitude) changes of the ion flux. A considerable fraction of these fronts (about 50%) has an inclination to the plane perpendicular to the Sun–Earth line that exceeds 30°.