The design of the attitude control system for the orbiting geophysical observatory
Attitude control system for orbiting geophysical observatory
SATELLITE INSTRUMENTATION↗
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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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GT-MSOCC - A domain for research on human-computer interaction and decision aiding in supervisory control systems
The Georgia Tech-Multisatellite Operations Control Center (GT-MSOCC), a real-time interactive simulation of the operator interface to a NASA ground control system for unmanned earth-orbiting satellites, is described. The GT-MSOCC program for investigating a range of modeling, decision aiding, and workstation design issues related to the human-computer interaction is discussed. A GT-MSOCC operator function model is described in which operator actions, both cognitive and manual, are represented as the lowest level discrete control network nodes, and operator action nodes are linked to information needs or system reconfiguration commands.
Mitchell, Christine M.↗
Rationale for selection of a flight control system for lift cruise fan V/STOL aircraft
Various features of the lift cruise fan V/STOL concept are briefly reviewed. The ability to operate from small ships in adverse weather, low visibility, and rough sea conditions is emphasized as is the need for a highly capable, flexible, and reliabile flight control system. A three channel control by wire, digital flight control system is suggested. The requirement for automatic flight control, the advantage of control by wire implementation, the preference for a digital computer, and the need for three channel redundancy are among the factors discussed.
Konsewicz, R. K.↗
Integrated control system for a gas turbine engine
A control system for a turbofan engine receives signals from a number of engine sensors and from the engine operator, and generates control signals. One control signal regulates the fan exhaust nozzle area in order to control inlet throat Mach number to maintain a low level of engine noise. Additional control signals regulate fuel flow to control engine thrust and fan pitch to control fan speed. A number of schedules are utilized to maintain a predetermined relationship between the controlled parameters and a number of fixed and calculated limits can override the control signals to prevent unsatisfactory engine performance.
Cornett, J. E.↗
A learning flight control system for the F8-DFBW aircraft
This report contains a complete description of a learning control system designed for the F8-DFBW aircraft. The system is parameter-adaptive with the additional feature that it 'learns' the variation of the control system gains needed over the flight envelope. It, thus, generates and modifies its gain schedule when suitable data are available. The report emphasizes the novel learning features of the system: the forms of representation of the flight envelope and the process by which identified parameters are used to modify the gain schedule. It contains data taken during piloted real-time 6 degree-of-freedom simulations that were used to develop and evaluate the system.
Montgomery, R. C.↗
Orion Service Module Reaction Control System Plume Impingement Analysis Using PLIMP/RAMP2
The Orion Crew Exploration Vehicle Service Module Reaction Control System engine plume impingement was computed using the plume impingement program (PLIMP). PLIMP uses the plume solution from RAMP2, which is the refined version of the reacting and multiphase program (RAMP) code. The heating rate and pressure (force and moment) on surfaces or components of the Service Module were computed. The RAMP2 solution of the flow field inside the engine and the plume was compared with those computed using GASP, a computational fluid dynamics code, showing reasonable agreement. The computed heating rate and pressure using PLIMP were compared with the Reaction Control System plume model (RPM) solution and the plume impingement dynamics (PIDYN) solution. RPM uses the GASP-based plume solution, whereas PIDYN uses the SCARF plume solution. Three sets of the heating rate and pressure solutions agree well. Further thermal analysis on the avionic ring of the Service Module showed that thermal protection is necessary because of significant heating from the plume.
Wang, Xiao-Yen J.↗
Orion Service Module Reaction Control System Plume Impingement Analysis Using PLIMP/RAMP2
The Orion Crew Exploration Vehicle Service Module Reaction Control System engine plume impingement was computed using the plume impingement program (PLIMP). PLIMP uses the plume solution from RAMP2, which is the refined version of the reacting and multiphase program (RAMP) code. The heating rate and pressure (force and moment) on surfaces or components of the Service Module were computed. The RAMP2 solution of the flow field inside the engine and the plume was compared with those computed using GASP, a computational fluid dynamics code, showing reasonable agreement. The computed heating rate and pressure using PLIMP were compared with the Reaction Control System plume model (RPM) solution and the plume impingement dynamics (PIDYN) solution. RPM uses the GASP-based plume solution, whereas PIDYN uses the SCARF plume solution. Three sets of the heating rate and pressure solutions agree well. Further thermal analysis on the avionic ring of the Service Module was performed using MSC Patran/Pthermal. The obtained temperature results showed that thermal protection is necessary because of significant heating from the plume.
Wang, Xiao-Yen↗
Commutated automatic gain control system
The commutated automatic gain control (AGC) system was designed and built for the prototype Loran-C receiver is discussed. The current version of the prototype receiver, the Mini L-80, was tested initially in 1980. The receiver uses a super jolt microcomputer to control a memory aided phase loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The AGC control adjusts the level of each station signal, such that the early portion of each envelope rise is about at the same amplitude in the receiver envelope detector.
Yost, S. R.↗
A Selected Operational History of the Internal Thermal Control System (ITCS) for International Space Station (ISS)
The Internal Thermal Control System (ITCS) has been developed jointly by Boeing Corporation, Huntsville, Alabama and Honeywell Engines & Systems, Torrance, California to meet the internal thermal control needs for the International Space Station (ISS). The ITCS provides heat removal for the critical life support systems and thermal conditioning for numerous experiment racks. The ITCS will be fitted on a number of modules on the ISS. The first US Element containing the ITCS, Node 1, was launched in December 1998. Since Node 1 does not contain a pump to circulate the fluid it was not filled with ITCS fluid until after the US Laboratory Module was installed. The second US Element module, US Laboratory Module, which contains the pumps and all the major ITCS control hardware, was launched in February 2001. The third US Element containing the ITCS, the US Airlock, was launched in July 2001. The dual loop system of the ITCS is comprised of a lowtemperature loop (LTL) and a moderate-temperature loop (MTL). Each loop has a pump package assembly (PPA), a system flow control assembly (SFCA), a threeway mixing valve (TWMV), several rack flow control assemblies (RFCA), cold plates, pressure sensors, temperature sensors, pump bypass assembly (PBA) and a heat exchanger. In addition, the MTL has an additional TWMV, a payload regeneration heat exchanger (P/RHE) and a manual flow control valve (MFCV). The LTL has a service performance and checkout unit (SPCU) heat exchanger. The two loops are linked via one loop crossover assembly (LCA) providing cross loop capabilities and a single PPA, two-loop functionality. One important parameter monitored by the ground stations and on-orbit is the amount of fluid leakage from the ITCS. ISS fluid leakage is of importance since ITCS fluid is costly to re-supply, may be difficult to clean up in zero-g, and if uncontained could lead to equipment failures and potential hazards. This paper examines the nominal leakage observed over period of a year of on-orbit operation and compares this with analysis predictions. This paper also addresses the off-nominal leakage and a fluid transfer event causing significant changes in accumulator quantity.
Patel, Vipul P.↗
R&D 100 Winner 2017: Control System for Active Damping of Inter-Area Oscillations
Researchers at Sandia National Labs have developed a control system to improve damping of inter-area oscillations to improve power grid reliability. Current grids operate will below transmission capacity to avoid widespread outages due to inter-area oscillations. This control system is the first successful grid demonstration of feedback control making it a game changer for the smart grid.
24 POWER TRANSMISSION AND DISTRIBUTION↗
Pointing and figure control system for a space-based far-IR segmented telescope
A pointing and figure control system for two space-based far-IR telescopes, the 10-20 m Large Deployable Reflector and the 3.6 m Submillimeter Intermediate Mission, is described. The figure maintenance control system is designed to counter the optical elements translational and rotational changes induced by long-term thermal drifts that the support structure may experience. The pointing system applies optical truss to telescope pointing; a laser metrology system is used to transfer pointing informaton from an external fine guidance sensor to the telescope optical boresight, defined by the primary mirror, secondary mirror, and focal plane assembly.
Lau, Kenneth↗
Spaceport Command and Control System Support Software Development
The Spaceport Command and Control System (SCCS) is a project developed and used by NASA at Kennedy Space Center in order to control and monitor the Space Launch System (SLS) at the time of its launch. One integral subteam under SCCS is the one assigned to the development of a data set building application to be used both on the launch pad and in the Launch Control Center (LCC) at the time of launch. This web application was developed in Ruby on Rails, a web framework using the Ruby object-oriented programming language, by a 15 - employee team (approx.). Because this application is such a huge undertaking with many facets and iterations, there were a few areas in which work could be more easily organized and expedited. As an intern working with this team, I was charged with the task of writing web applications that fulfilled this need, creating a virtual and highly customizable whiteboard in order to allow engineers to keep track of build iterations and their status. Additionally, I developed a knowledge capture web application wherein any engineer or contractor within SCCS could ask a question, answer an existing question, or leave a comment on any question or answer, similar to Stack Overflow.
Knowledge Transfer↗
Implementation of an Adaptive Controller System from Concept to Flight Test
The National Aeronautics and Space Administration Dryden Flight Research Center (Edwards, California) is conducting ongoing flight research using adaptive controller algorithms. A highly modified McDonnell-Douglas NF-15B airplane called the F-15 Intelligent Flight Control System (IFCS) is used to test and develop these algorithms. Modifications to this airplane include adding canards and changing the flight control systems to interface a single-string research controller processor for neural network algorithms. Research goals include demonstration of revolutionary control approaches that can efficiently optimize aircraft performance in both normal and failure conditions and advancement of neural-network-based flight control technology for new aerospace system designs. This report presents an overview of the processes utilized to develop adaptive controller algorithms during a flight-test program, including a description of initial adaptive controller concepts and a discussion of modeling formulation and performance testing. Design finalization led to integration with the system interfaces, verification of the software, validation of the hardware to the requirements, design of failure detection, development of safety limiters to minimize the effect of erroneous neural network commands, and creation of flight test control room displays to maximize human situational awareness; these are also discussed.
Larson, Richard R.↗
Thermal Control System Automation Project (TCSAP)
Information is given in viewgraph form on the Space Station Freedom (SSF) Thermal Control System Automation Project (TCSAP). Topics covered include the assembly of the External Thermal Control System (ETCS); the ETCS functional schematic; the baseline Fault Detection, Isolation, and Recovery (FDIR), including the development of a knowledge based system (KBS) for application of rule based reasoning to the SSF ETCS; TCSAP software architecture; the High Fidelity Simulator architecture; the TCSAP Runtime Object Database (RODB) data flow; KBS functional architecture and logic flow; TCSAP growth and evolution; and TCSAP relationships.
Boyer, Roger L.↗
Verification test results of Apollo stabilization and control systems during undocked operations
The results are presented of analysis and simulation testing of both the Skylark 1 reaction control system digital autopilot (RCS DAP) and the thrust vector control (TVC) autopilot for use during the undocked portions of the Apollo/Soyuz Test Project Mission. The RCS DAP testing was performed using the Skylab Functional Simulator (SLFS), a digital computer program capable of simulating the Apollo and Skylab autopilots along with vehicle dynamics including bending and sloshing. The model is used to simulate three-axis automatic maneuvers along with pilot controlled manual maneuvers using the RCS DAP. The TVC autopilot was tested in two parts. A classical stability analysis was performed on the vehicle considering the effects of structural bending and sloshing when under control of the TVC autopilot. The time response of the TVC autopilot was tested using the SLFS. Results indicate that adequate performance stability margins can be expected for the CSM/DM configuration when under the control of the Apollo control systems tested.
Copeland, E. L.↗
On the Application of the Adaptive Principle for Increasing the Reliability of Flight Control Systems
Application of adaptive principle to increase reliability of aircraft flight control systems
FLIGHT CONTROL↗
Development of a Work Control System for Propulsion Testing at Stennis Space Center (SSC)
In 1996, Stennis Space Center was given management authority for all Propulsion Testing for NASA. Over the next few years several research and development (R&D) test facilities were completed and brought up to full operation in what is known as the E-Complex Test Facility at Stennis Space Center. This paper will explain the requirements and steps taken to develop the current Test Operations' electronic work control system. The Work Control System developed includes work authorization documents such as test preparation sheets, discrepancy reports, pre-test briefing reports, and test requests.
Messer, Elizabeth A.↗
Pterodactyl: Control System Design for Deployable Entry Vehicles
As space exploration missions continue to get more complex, greater demands for mass and volume are being placed on planetary entry vehicles. At the same time, the desire for precision entry targeting to enable surface missions at very specific locations is becoming common. Deployable aeroshells are one type of technology that is being developed to increase the down-mass capability of planetary entry vehicles while complying with current launch vehicle volume constraints. Propulsive control can be used for precision entry targeting but can require a large percentage of the vehicle's total mass or volume for propellant. The Pterodactyl project is studying alternative entry control systems on a Deployable Entry Vehicle to potentially introduce a mass and volume efficient entry system that can achieve precision targeting. This paper presents the mechanical design work undertaken to support the Pterodactyl trade study of three entry vehicle control system options: 1) Flaps, 2) Mass Movement, and 3) Reaction Control System.
D'Souza, Sarah↗