2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)最新文献

{"title":"A framework for metrics in large complex systems","authors":"G. Mack, K. Lonergan, J. Scholtz, M. Steves, C. Hale","doi":"10.1109/AERO.2004.1368127","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368127","url":null,"abstract":"Terrorism information awareness (TIA) was initiated by the Information Awareness Office (IAO) of the Defense Advanced Research Projects Agency (DARPA) (Snowden and Kurtz, 2002; 2003; Snowden, 2000). TIA capabilities enable the detection, classification, identification, and tracking of terrorist activities in order to provide early warning of plans and to identify options to prevent them from being executed. TIA operated as a research program in an environment with real data, real users, and real missions. This environment presented many challenges to the collection and analysis of metrics. Like most large things, the TIA program was a mixture of the \"complicated\" and the \"complex\". At a high level, the program could be considered as both a \"system\" and a human \"network\". The \"system\" is complicated, able to be analyzed from its constituent components. On the other hand, the \"network\" is a complex composite of the activities of small groups engaged in problem solving. To analyze TIA experiments, we adopted multiple interwoven sets of \"perspectives\" encompassing both the system and the net. All perspectives were engaged simultaneously. The first set of three, which defined the make up of the Metrics Team, were a cognitive perspective, an operational perspective, and a technical perspective. We also established five \"threads\" of functional capability to study the technologies: structured discovery, link and group understanding, decision-making with corporate memory, collaborative problem solving, and context-aware visualization. Finally, we established models of the operational context (mission, goals, and resources) for each of the collaboration groups, called \"scenarios\". The metrics for these analyses were derived using an explicit model based on a UML metrics meta-model. Presenting aggregated analyses in a way that fosters understanding without losing the appreciation of the complexities of the program is itself a complex task. Stones have the ability to organize the anecdotes surrounding events of interest in ways that the goals, values, and rules of the observed behaviors are revealed clearly. Our attempt at building such a \"story\" used a concept map as a framework.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125888754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconfigurable control and fault identification system","authors":"S. Black, K. Keller, K. Swearingen, M. Vandernoot, M. Hood, J. Urnes, A. Page","doi":"10.1109/AERO.2004.1368154","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368154","url":null,"abstract":"The integration of health management and reconfigurable flight control is demonstrated in the NAVAIR/Boeing Reconfigurable Control and Fault Identification System (RCF1S) Dual Use Science and Technology program (Contract N00421-003-0123). The major research results include: 1) expansion of diagnostic capability by detecting levels of actuator degradation that can be used to reduce could not duplicates and false alarms in the current BIT systems, 2) fusion of system and component level health assessment results, 3) the ability to perform structured tests of control system actuator components during flight when loads and temperature environment are present to enable a more accurate health assessment with no impact on the flight trajectory or ride quality, 4) modification of actuator controls in order to make the best use of the degraded actuator remaining capabilities and/or extend the life of the component and 5) modification of system level controls to compensate for the degraded component/subsystem capability or damage.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"238 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124623046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymmetric electrostatic radiation shielding for spacecraft","authors":"P. Metzger, R. Youngquist, J. Lane","doi":"10.1109/AERO.2004.1367649","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367649","url":null,"abstract":"The physics of the radiation shielding problem possess several asymmetries which may be exploited in electrostatics to obtain nearly isotropic protection without radial symmetry in the fields, a concept that has been overlooked in previous studies. Electrostatic shielding is advantageous because it solves the problem of secondary radiation generated in passive shields and allows passive shields to be smaller and more directional. This paper present the results of computer simulations for a linear quadrupole configuration to demonstrate shielding effectiveness for protons and high-Z, high-energy particles, while at the same time driving away thermal electrons. The study indicates that this shielding method is nearly feasible with existing technology, and only modest gains may be needed to make it a reality.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124761462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel approach to aircraft engine anomaly detection and diagnostics","authors":"Lijie Yu, Daniel J. Cleary, P. Cuddihy","doi":"10.1109/AERO.2004.1368152","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368152","url":null,"abstract":"Accurate and timely failure detection and diagnosis is critical to reliable and affordable aircraft engine operation. This work describes a statistical and fuzzy logic based approach that analyzes multiple engine performance parameters for trend recognition, shift evaluation and failure classification. It integrates the statistical data analysis and fuzzy logic reasoning processes and provides powerful data fusion capability. The system captures and diagnoses failures as soon as the engine performance-shifting trend is recognizable, based on customizable probability. This approach improves upon current diagnostic processes in a number of ways. First, the dimensionality is increased so that multiple relevant parameters are integrated into the diagnosis. This helps reduce single dimension false alarms. Second, this approach effectively handles the noise in engine performance data. Many diagnoses depend on detecting changes in the data that fall within three standard deviations of the pre-event data, historically leading to false alerts and diagnoses. Finally, this approach seamlessly integrates the noise in the data with the uncertainty in the diagnostic models, rolling it up into a single score for each potential diagnosis. This increases consistency, and removes a substantial amount of subjective judgment from the diagnostic process. This approach has been successfully applied to a series of General Electric commercial airline engines, demonstrating high accuracy and consistency. The methodology is expected to be generally applicable to a wide variety of engine models and failure modes.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"47 35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124864051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative methods for maturing and infusing advanced spacecraft technology","authors":"S. Cornford, L. Sarsfield","doi":"10.1109/AERO.2004.1367652","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367652","url":null,"abstract":"Today, the pace of spacecraft development has accelerated. Some of the pressure to accelerate comes from reduced budgets and government mandates to improve efficiency and rely on a greater extent on commercial systems and practices. More importantly, however, the accelerating pace is driven by new opportunities in science and technology. Future systems must respond to requirements to deliver higher resolution, greater responsiveness, and the increased need for interoperability. Additionally, NASA is being asked to field systems in less time and less cost without sacrificing mission reliability. To meet these often contradictory requirements, project managers must find new ways to infuse advanced technologies into spacecraft. As a result, most of NASA's science spacecraft incorporate an unprecedented amount of new technology. Candidate missions must identify new systems and components, analyze how the risks associated with new designs are to be mitigated, and identify methods for transferring resultant technology within and outside of NASA. Technology infusion in any application is a complex process. Incorporating an unproven new design into the development of an operational system presents significant cost, schedule, and technical risk. Historically, developers of operational systems have been cautious when incorporating new technology. New designs are often matured independent of operational systems and brought online only when they have proven their mettle. Demonstrator or precursor missions are used to test new designs before the commitment to a new technology is made. This is usually a very slow process; it can take years or decades to move a technology from the laboratory to fully operational status. The result is a stepwise evolution of capability - an approach that minimizes risk. Sometimes requirements evolve at a pace where demonstrator programs are not possible. When this occurs, project managers must accept the task of integrating complex new technologies into the mainstream development of an operational spacecraft. The tools used to assist the project manager with this task are surprisingly fragile. Techniques for measuring the readiness of a technology, for example, are highly qualitative. The importance of the language and culture surrounding the transfer of a technology from the laboratory to the application program is also generally underestimated. This paper focuses on these issues, examining the practice of maturing technology with special emphasis on methods that improve the integration of advanced designs during the development of operational spacecraft systems. Simplified practices are presented that could improve the accuracy and reduce the risk associated with estimating the readiness of a technology for use in space applications. While This work focuses on the challenges associated with building spacecraft, the authors believe the practices presented here could have broader application to other markets.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129458356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fault detection and isolation in the NT-OMS/RCS","authors":"M. Azam, D. Pham, F. Tu, K. Pattipati, N. Patterson-Hine, Lui Wang","doi":"10.1109/AERO.2004.1368096","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368096","url":null,"abstract":"In this paper, we consider the problem of test design for real-time fault detection and diagnosis in the Space Shuttle's non-toxic orbital maneuvering system and reaction control system (NT-OMS/RCS). For demonstration purposes, we restrict our attention to the shaft section of the NT-OMS/RCS, which consists of 160 faults (each fault being either a leakage, blockage, igniter fault, or regulator fault) and 128 sensors. Using the proposed tests, we are able to uniquely isolate a large number of the faults of interest in the NT-OMS/RCS. Those that cannot be uniquely isolated can generally be resolved into small ambiguity groups and then uniquely isolated via manual/automated commands. Simulation of the NT-OMS/RCS under various fault conditions was conducted using the TRICK/sup /spl reg// modeling software.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128166395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Initiating the 2002 Mars Science Laboratory (MSL) focused technology program","authors":"Robert T. Caffrey, G. Udomkesmalee, Samad A. Hayati","doi":"10.1109/AERO.2004.1367650","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367650","url":null,"abstract":"The Mars Science Laboratory (MSL) Project is an aggressive mission launching in 2009 to deliver a new generation of rover safely to the surface of Mars and conduct comprehensive in situ investigations using a new generation of instruments. This system is designed to land with precision and be capable of operating over a large percentage on the surface of Mars. It has capabilities that support NASA's scientific goals into the next decade of exploration. The MSL technology program is developing a wide-range of technologies needed for this mission and potentially other space missions. The MSL technology program reports to both the MSL Project and the Mars technology program (MTP). The dual reporting process creates a challenging management situation, but ensures the new technology meets both the specific MSL requirements and the broader Mars program requirements. MTP is a NASA-wide technology development program managed by the Jet Propulsion Laboratory (JPL) and is divided into a focused program and a base program. The focused technology program addresses technologies that are specific and critical to near-term missions, while the base technology program addresses those technologies that are applicable to multiple missions and which can be characterized as longer term, higher risk, and high payoff technologies. The MSL technology program is under the focused program and is tightly coupled to MSL's mission milestones and deliverables. The technology budget is separate from the flight project budget, but the technology's requirements and the development process are tightly coordinated with the project. The technology program combines proven management techniques of flight projects with commercial and academic technology management strategies, to create a technology management program that meets the near-term requirements of MSL and the long-term requirements of MTP. This paper examines the initiation of 2002 MSL technology program. Some of the areas discussed in this paper include technology definition, task selection, technology management, and technology assessment.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128608068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TeraHertz operational reachback (THOR) a mobile free space optical network program","authors":"B. Stadler, G. Duchak","doi":"10.1109/AERO.2004.1367948","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367948","url":null,"abstract":"The DARPA teraHertz operational reachback (THOR) program developed and assessed a suite of technologies for application in a mobile ad-hoc free space optical communication system. The notional THOR system includes airborne and ground based full duplex active terminals and passive optical terminals that form the physical layer of a high speed ad hoc mobile optical network. THOR consists of airborne terminals networked to form a communications backbone transmitting and receiving data at 2.5Gbps as well as passive optical terminals connected as high speed edge devices with a data rate of 200Mbps. The operational objective is to enable high data rate communications between a combat theater command post and an edge terminal linked to the global information grid (GIG) located outside of theater. DARPA investments were made in compact electro-optic beam steering devices to decrease the size and weight of optical terminals, high-speed high sensitivity (-47dBm) detectors, and high power (50W) modulating laser sources. Passive optical terminal technology investments focused on highspeed modulating quantum well focal plane arrays for integration with wide field of view +/-15 degree cat's eye optical systems to enable high speed modulating retro reflectors. Networking technologies included protocol assessments and quality of service algorithms to maintain low latency data transfer over unreliable optical data channels while maintaining data rates in the 2.5Gbps range. Analysis and network simulation results demonstrated that with multiple redundant links an all-optical network could operate with atmospheric weather conditions consisting of 80% broken cloud cover.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129655742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Joint subspace detection of hyperspectral targets","authors":"A. Schaum","doi":"10.1109/AERO.2004.1367963","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367963","url":null,"abstract":"Joint subspace detection (JSD) arises from a Bayesian formulation of the binary detection problem, as contrasted with the \"fixed but unknown parameter\" approach that generates the generalized likelihood ratio (GLR) test. The Bayesian philosophy allows the incorporation of prior knowledge gleaned from empirical experience into the design of a detection algorithm. The knowledge appears in the form of probability distributions for parameters considered deterministic in the GLR method. An example of this principle, called complementary subspace detection, has been applied to hyperspectral data and, with appropriate subspace selection, is shown to outperform the traditional detection techniques over a wide range of assumed prior knowledge of target distribution.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129099036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"System engineering for spaceborne optical interferometers","authors":"Riley M. Duren","doi":"10.1109/AERO.2004.1368006","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368006","url":null,"abstract":"Spaceborne optical interferometry truly represents uncharted territory - one in which the community developing such missions is still \"learning the ropes\". This paper is based on a collection of lessons-learned based on related missions including StarLight, a formation-flying stellar interferometry mission that merged with the Terrestrial Planet Finder technology development program just prior to entering phase C/D, the Space Interferometry Mission (currently in phase B), and the Shuttle Radar Topography Mission (a radar interferometer which flew in 2000). In first order, optical interferometry missions differ from classical deep-space science missions in several key respects: they are highly distributed systems, they are sensitive to small, cross-coupling error sources, and their operation is very complex. This leads to three unique system engineering challenges associated with implementing such missions: error handling and performance modeling, validation and verification (V&V), and system robustness. With an upcoming suite of interferometry missions approaching the transition from technology-development mode to flight project implementation mode the time is ripe for a discussion of these challenges and proposed solutions.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126970473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}