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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9

Autonomous power expert fault diagnostic system for Space Station Freedom electrical power system testbed

The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control to the Space Station Freedom Electrical Power System (SSF/EPS) testbed being developed and demonstrated at NASA Lewis Research Center. The objectives of the program are to establish artificial intelligence technology paths, to craft knowledge-based tools with advanced human-operator interfaces for power systems, and to interface and integrate knowledge-based systems with conventional controllers. The Autonomous Power EXpert (APEX) portion of the APS program will integrate a knowledge-based fault diagnostic system and a power resource planner-scheduler. Then APEX will interface on-line with the SSF/EPS testbed and its Power Management Controller (PMC). The key tasks include establishing knowledge bases for system diagnostics, fault detection and isolation analysis, on-line information accessing through PMC, enhanced data management, and multiple-level, object-oriented operator displays. The first prototype of the diagnostic expert system for fault detection and isolation has been developed. The knowledge bases and the rule-based model that were developed for the Power Distribution Control Unit subsystem of the SSF/EPS testbed are described. A corresponding troubleshooting technique is also described.

Truong, Long V.↗

Full-Scale Development and Piloting of a Hybrid Digital Twin for Wastewater Operations Optimization

This full-scale pilot of a machine learning based nutrient controller/digital twin is being done as part of The Water Research Foundation (WRF) project 5121: Development of Innovative Predictive Control Strategies for Nutrient Removal. The overall goal of this project is to develop and full-scale test a hybrid (machine learning + mechanistic model) nutrient management controller at four different water resource recovery facilities (WRRFs). The controller demonstrates both short-term optimization functions and predictive capabilities. This project includes the design of the controller, its performance at the WRRFs, and a description of the future improvements.

Johnson, Bruce↗

A computational algorithm for spacecraft control and momentum management

Developments in the area of nonlinear control theory have shown how coordinate changes in the state and input spaces of a dynamical system can be used to transform certain nonlinear differential equations into equivalent linear equations. These techniques are applied to the control of a spacecraft equipped with momentum exchange devices. An optimal control problem is formulated that incorporates a nonlinear spacecraft model. An algorithm is developed for solving the optimization problem using feedback linearization to transform to an equivalent problem involving a linear dynamical constraint and a functional approximation technique to solve for the linear dynamics in terms of the control. The original problem is transformed into an unconstrained nonlinear quadratic program that yields an approximate solution to the original problem. Two examples are presented to illustrate the results.

Dzielski, John↗

An Open Specification for Space Project Mission Operations Control Architectures

An 'open specification' for Space Project Mission Operations Control Architectures is under development in the Spacecraft Control Working Group of the American Institute for Aeronautics and Astro- nautics. This architecture identifies 5 basic elements incorporated in the design of similar operations systems: Data, System Management, Control Interface, Decision Support Engine, & Space Messaging Service.

spacecraft ground systems↗

A New Approach to Mission Classification and Risk Management for NASA Space Flight Missions

The NASA risk classification system is meant to uide space mission development from formulation through completion of implementation. It is also meant to be the basis on which program and project managers develop and implement appropriate mission assurance and risk management strategies for the mission. In order to be useful, the risk classification system needs to provide consistent and reproducible classification results so that missions may be designed with the appropriate components, subsystems, and testing philosophy, all of which impacts mission schedule and cost. In a cost-constrained environment, a clear, robust, and reproducible approach to mission implementation becomes more critical than ever before. Once a project's risk classification level is established, the managers can define the appropriate management controls, systems engineering processes, mission assurance requirements, safety, and testing for that mission. The current NASA mission classification system will be reviewed before a new system is proposed.NASA manages space flight missions according to a four-tiered classification which assumes increasing levels of risk. We argue that risk does not change between classes. What changes are the means available to reduce risk. In performance-driven missions, the project will spend money in order to maintain performance without reducing margins. In cost-constrained missions, performance will be reduced in order to stay within budget or to maintain schedule: measurement requirements may be traded, design life may be reduced, or both. We then propose a new approach to the classification of NASA space flight missions, based on an assessment of how flexible the requirements, how exquisite the measurements, how long the lifetime, and how rigid the budget.Our proposed approach makes possible a clearer differentiation between classification levels and more effective guidance to program and project managers.

Bordi, Francesco↗

Human-In-The-Loop Investigation of Interoperability Between Terminal Sequencing and Spacing, Automated Terminal Proximity Alert, and Wake-Separation Recategorization

A human-in-the-loop simulation study addressed terminal-area controller-workstation interface variations for interoperability between three new capabilities being introduced by the FAA. The capabilities are Terminal Sequencing and Spacing (TSAS), Automated Terminal Proximity Alert (ATPA), and wake-separation recategorization, or 'RECAT.' TSAS provides controllers with Controller-Managed Spacing (CMS) tools, including slot markers, speed advisories, and early/late indications, together with runway assignments and sequence numbers. ATPA provides automatic monitor, warning, and alert cones to inform controllers about spacing between aircraft on approach. ATPA cones are sized according to RECAT, an improved method of specifying wake-separation standards. The objective of the study was to identify potential issues and provide recommendations for integrating TSAS with ATPA and RECAT. Participants controlled arrival traffic under seven different display configurations, then tested an 'exploratory' configuration developed with participant input. All the display conditions were workable and acceptable, but controllers strongly preferred having the CMS tools available on Feeder positions, and both CMS tools and ATPA available on Final positions. Controllers found the integrated systems favorable and liked being able to tailor configurations to individual preferences.

ATD-1↗

Retrofitting Laboratory Fume Hoods With Face Velocity Monitors at NASA Lewis Research Center

Extensive use and reliance on laboratory fume hoods exist at LeRC for the control of chemical hazards (nearly 175 fume hoods). Flow-measuring devices are necessary to continually monitor hood performance. The flow-measuring device should he tied into an energy management control system to detect problems at a central location without relying on the users to convey information of a problem. Compatibility concerns and limitations should always be considered when choosing the most effective flow-measuring device for a particular situation. Good practice on initial hood design and placement will provide a system for which a flow-measuring device may be used to its full potential and effectiveness.

Wagner, Ingrid E.↗

Installation package for integrated programmable electronic controller and hydronic subsystem - solar heating and cooling

A description is given of the Installation, Operation, and Maintenance Manual and information on the power panel and programmable microprocessor, a hydronic solar pump system and a hydronic heating hot water pumping system. These systems are integrated into various configurations for usages in solar energy management, control and monitoring, lighting control, data logging and other solar related applications.

Source record↗

Ground Operations Autonomous Control and Integrated Health Management

An intelligent autonomous control capability has been developed and is currently being validated in ground cryogenic fluid management operations. The capability embodies a physical architecture consistent with typical launch infrastructure and control systems, augmented by a higher level autonomous control (AC) system enabled to make knowledge-based decisions. The AC system is supported by an integrated system health management (ISHM) capability that detects anomalies, diagnoses causes, determines effects, and could predict future anomalies. AC is implemented using the concept of programmed sequences that could be considered to be building blocks of more generic mission plans. A sequence is a series of steps, and each executes actions once conditions for the step are met (e.g. desired temperatures or fluid state are achieved). For autonomous capability, conditions must consider also health management outcomes, as they will determine whether or not an action is executed, or how an action may be executed, or if an alternative action is executed instead. Aside from health, higher level objectives can also drive how a mission is carried out. The capability was developed using the G2 software environment (www.gensym.com) augmented by a NASA Toolkit that significantly shortens time to deployment. G2 is a commercial product to develop intelligent applications. It is fully object oriented. The core of the capability is a Domain Model of the system where all elements of the system are represented as objects (sensors, instruments, components, pipes, etc.). Reasoning and decision making can be done with all elements in the domain model. The toolkit also enables implementation of failure modes and effects analysis (FMEA), which are represented as root cause trees. FMEA's are programmed graphically, they are reusable, as they address generic FMEA referring to classes of subsystems or objects and their functional relationships. User interfaces for integrated awareness by operators have been created.

Figueroa, Fernando↗

Abstracting event-based control models for high autonomy systems

A high autonomy system needs many models on which to base control, management, design, and other interventions. These models differ in level of abstraction and in formalism. Concepts and tools are needed to organize the models into a coherent whole. The paper deals with the abstraction processes for systematic derivation of related models for use in event-based control. The multifaceted modeling methodology is briefly reviewed. The morphism concepts needed for application to model abstraction are described. A theory for supporting the construction of DEVS models needed for event-based control is then presented. An implemented morphism on the basis of this theory is also described.

Luh, Cheng-Jye↗

Kennedy Space Center's Command and Control System - "Toasters to Rocket Ships"

This slide presentation reviews the history of the development of the command and control system at Kennedy Space Center. From a system that could be brought to Florida in the trunk of a car in the 1950's. Including the development of larger and more complex launch vehicles with the Apollo program where human launch controllers managed the launch process with a hardware only system that required a dedicated human interface to perform every function until the Apollo vehicle lifted off from the pad. Through the development of the digital computer that interfaced with ground launch processing systems with the Space Shuttle program. Finally, showing the future control room being developed to control the missions to return to the moon and Mars, which will maximize the use of Commercial-Off-The Shelf (COTS) hardware and software which was standards based and not tied to a single vendor. The system is designed to be flexible and adaptable to support the requirements of future spacecraft and launch vehicles.

Lougheed, Kirk↗

Space Station Freedom - Technical and management challenges

The development of the Space Station is reviewed, focusing on the technical and managerial aspects of the program. The optimization of the Space Station configuration, utilization impacts on design, technical aspects of the distribution systems, and the problems of designing for a lifetime of 30 years or more are discussed. In addition, cost reduction studies, testing and verification, determining the assembly sequence, and operational communications and support systems are examined. Managerial aspects of the program include organization, program control, management tools and processes, and the integration of elements from the international partners.

Moser, Thomas L.↗

Airbus windshear warning and guidance system

From its first designed airplane, Airbus considered mandatory a help in the crew's decision-making process to initiate an escape maneuver and help to successfully realize it. All the Airbus airplanes designed since 1975 included an alpha-floor function and a speed reference control law imbedded in the speed reference system (SRS) box for A 300 and FAC and FCC for A 310, A300/600 and the A 320. Alpha-Floor function takes into account the airplane energy situation considering angle of attack and observed longitudinal situation in order to apply immediately the full power without any pilot action. Speed reference managers control airspeed and/or ground speed in order to survive a maximum in shear situation. In order to comply with the new FAA regulation: Aerospatiale and Airbus developed more efficient systems. A comparison between 1975 and a newly developed system is given. It is explained how the new system improves the situation.

Bonafe, J. L.↗

Where is the Human in the Loop? Human Factors Analysis of Extended Visual Line of Sight Unmanned Aerial System Operations within a Remote Operations Environment

Many envisioned technological and conceptual innovations focus on allocating more functions to automation, relegating the human as an afterthought if not a nuisance. Yet, until complete autonomy is realized, the human will remain “in the loop”. The National Aeronautics and Space Administration is supporting research for the development and maturation of automated technologies and architectures for the future of advanced air mobility. Standing up a remote operations center used to control, manage, and monitor multiple highly automated vehicles is an important step towards realizing the advanced air mobility vision. At the National Aeronautics and Space Administration’s Langley Research Center, a remote operation center exists and has been tested using humans piloting simulated vehicles. In this paper, we explore the human element within live flight operations that rely on increasingly automated technologies. Four ground control station operators performed multiple live flight operations. We employed a naturalistic approach and relied on qualitative data such as interviews and discussions with subject matter experts to help facilitate discovery. The present work evaluates the functions that the human and the automation had during the live operations, lists psychological constructs that may have promoted or reduced task performance, and provides recommendations on design of the remote operations environment and training of future ground control station operators.

Advanced Air Mobility↗

Where is the Human in the Loop? Human Factors Analysis of Extended Visual Line of Sight Unmanned Aerial System Operations within a Remote Operations Environment

Many envisioned technological and conceptual innovations focus on allocating more functions to automation, relegating the human as an afterthought if not a nuisance. Yet, until complete autonomy is realized, the human will remain “in the loop”. The National Aeronautics and Space Administration is supporting research for the development and maturation of automated technologies and architectures for the future of advanced air mobility. Standing up a remote operations center used to control, manage, and monitor multiple highly automated vehicles is an important step towards realizing the advanced air mobility vision. At the National Aeronautics and Space Administration’s Langley Research Center, a remote operation center exists and has been tested using humans piloting simulated vehicles. In this paper, we explore the human element within live flight operations that rely on increasingly automated technologies. Four ground control station operators performed multiple live flight operations. We employed a naturalistic approach and relied on qualitative data such as interviews and discussions with subject matter experts to help facilitate discovery. The present work evaluates the functions that the human and the automation had during the live operations, lists psychological constructs that may have promoted or reduced task performance, and provides recommendations on design of the remote operations environment and training of future ground control station operators.

Advanced Air Mobility↗

The NASA Jitter Handbook Development Activity: A Multidisciplinary Collaborative Effort

Spaceflight missions hosting high-performance vibration-sensitive optical sensor payloads with stringent pointing stability requirements are especially challenged in the areas of predicting, managing, controlling, and testing spacecraft line-of-sight (LoS) jitter. The community recognizes that this is a formidable multidisciplinary engineering task. However, while some textbooks and references in the aerospace literature may touch on the subject of jitter, important details of specific flight proven methodologies and techniques used by today’s jitter engineering practitioners are not readily accessible. There is no know engineering reference document with guidelines and best practices for managing and mitigating space-craft jitter. To fill this knowledge gap the NASA Engineering and Safety Center (NESC) has undertaken the task of developing a NASA Jitter Handbook which would include lessons learned and best practices for design, analysis, and test, along with operational guidelines to mitigate jitter. In this paper the plan for this handbook development will be described along with the envisioned handbook framework, key NASA stakeholders, and potential envisioned jitter engineering case studies. Opportunities exist technical collaboration on this handbook with NASA-external organizations.

Christopher D'Souza↗

A Multiple Agent Model of Human Performance in Automated Air Traffic Control and Flight Management Operations

A predictive model of human operator performance (flight crew and air traffic control (ATC)) has been developed and applied in order to evaluate the impact of automation developments in flight management and air traffic control. The model is used to predict the performance of a two person flight crew and the ATC operators generating and responding to clearances aided by the Center TRACON Automation System (CTAS). The purpose of the modeling is to support evaluation and design of automated aids for flight management and airspace management and to predict required changes in procedure both air and ground in response to advancing automation in both domains. Additional information is contained in the original extended abstract.

Corker, Kevin↗

Work Breakdown Structure (WBS) Handbook

The purpose of this document is to provide program/project teams necessary instruction and guidance in the best practices for Work Breakdown Structure (WBS) and WBS dictionary development and use for project implementation and management control. This handbook can be used for all types of NASA projects and work activities including research, development, construction, test and evaluation, and operations. The products of these work efforts may be hardware, software, data, or service elements (alone or in combination). The aim of this document is to assist project teams in the development of effective work breakdown structures that provide a framework of common reference for all project elements. The WBS and WBS dictionary are effective management processes for planning, organizing, and administering NASA programs and projects. The guidance contained in this document is applicable to both in-house, NASA-led effort and contracted effort. It assists management teams from both entities in fulfilling necessary responsibilities for successful accomplishment of project cost, schedule, and technical goals. Benefits resulting from the use of an effective WBS include, but are not limited to: providing a basis for assigned project responsibilities, providing a basis for project schedule development, simplifying a project by dividing the total work scope into manageable units, and providing a common reference for all project communication.

Source record↗