Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “COMMAND SYSTEM”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS2008

A Flight Control System Architecture for the NASA AirSTAR Flight Test Infrastructure

A flight control system architecture for the NASA AirSTAR infrastructure has been designed to address the challenges associated with safe and efficient flight testing of research control laws in adverse flight conditions. The AirSTAR flight control system provides a flexible framework that enables NASA Aviation Safety Program research objectives, and includes the ability to rapidly integrate and test research control laws, emulate component or sensor failures, inject automated control surface perturbations, and provide a baseline control law for comparison to research control laws and to increase operational efficiency. The current baseline control law uses an angle of attack command augmentation system for the pitch axis and simple stability augmentation for the roll and yaw axes.

Murch, Austin M.↗
NASA NTRS2004

The Case for Deep Space Telecommunications Relay Stations

Each future mission to Jupiter and beyond must carry the traditional suite of telecommunications systems for command and control and for mission data transmission to earth. The telecommunications hardware includes the large antenna and the high-power transmitters that enable the communications link. Yet future spacecraft will be scaled down from the hallmark missions of Galileo and Cassini to Jupiter and Saturn, respectively. This implies that a higher percentage of the spacecraft weight and power must be dedicated to telecommunications system. The following analysis quantifies this impact to future missions and then explores the merits of an alternative approach using deep space relay stations for the link back to earth. It will be demonstrated that a telecommunications relay satellite would reduce S/C telecommunications weight and power sufficiently to add one to two more instruments.

Chandler, Charles W.↗
NASA NTRS2018

Narrowband Propagation Statistics of Aeronautical Mobile-Ground Links in the L- and C-Bands

To provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System (NAS), command and control (C2) links must be highly reliable. Hence, protected aviation spectrum is required to support such links for UAS that are integrated into controlled non-segregated airspace. For air-ground (i.e., non-satellite) links, protected aviation spectrum to support C2 links is available in the 960-1164 MHz (L) and 5030-5091 MHz (C) bands. The performance of any C2 system is critically dependent upon the characteristics of the air-ground (AG) channel. Therefore, as part of its UAS Integration in the NAS (UAS in the NAS) project, the U.S. National Aeronautics and Space Administration (NASA) performed a series of air-ground propagation flight tests to collect AG channel data for model development and analysis of potential C2 communications links capable of providing the required reliability. NASA's Glenn Research Center (GRC) conducted an extensive air-ground channel propagation measurement campaign (at altitude) for frequencies in the 960-977 MHz and 5030-5091 MHz ranges, for seven different terrain environments. The measurements were conducted in 2013, and produced the largest set of AG channel data ever gathered to date. This data was subsequently processed to develop models for the AG channel. The statistics collected enabled the derivation of channel model parameters for both narrowband and wideband channels. In order to make the propagation data widely available, the resulting narrowband statistics were processed and submitted to the International Telecommunications Union - Radiocommunication Sector (ITU-R) Study Group 3 Data Banks. Formats for data tables were developed, and tables of the aggregate narrowband propagation statistics for the seven ground site terrain environments were prepared, submitted to, and approved by, the ITU-R Study Group 3. This paper provides brief background on the measurement campaign, collection and processing of data, and development of the narrowband data tables. It further provides examples of the data and its use.

radiofrequency spectrum↗
NASA NTRS2018

Narrowband Propagation Statistics of Aeronautical Mobile-Ground Links in the L- and C-Bands

To provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System (NAS), command and control (C2) links must be highly reliable. Hence, protected aviation spectrum is required to support such links for UAS that are integrated into controlled non-segregated airspace. For air-ground (i.e., non-satellite) links, protected aviation spectrum to support C2 links is available in the 960-1164 MHz (L) and 5030-5091 MHz (C) bands. The performance of any C2 system is critically dependent upon the characteristics of the air-ground (AG) channel. Therefore, as part of its UAS Integration in the NAS (UAS in the NAS) project, the U.S. National Aeronautics and Space Administration (NASA) performed a series of air-ground propagation flight tests to collect AG channel data for model development and analysis of potential C2 communications links capable of providing the required reliability. NASA's Glenn Research Center (GRC) conducted an extensive air-ground channel propagation measurement campaign (at altitude) for frequencies in the 960-977 MHz and 5030-5091 MHz ranges, for seven different terrain environments. The measurements were conducted in 2013, and produced the largest set of AG channel data ever gathered to date. This data was subsequently processed to develop models for the AG channel. The statistics collected enabled the derivation of channel model parameters for both narrowband and wideband channels. In order to make the propagation data widely available, the resulting narrowband statistics were processed and submitted to the International Telecommunications Union Radiocommunication Sector (ITU-R) Study Group 3 Data Banks. Formats for data tables were developed, and tables of the aggregate narrowband propagation statistics for the seven ground site terrain environments were prepared, submitted to, and approved by, the ITU-R Study Group 3. This paper provides brief background on the measurement campaign, collection and processing of data, and development of the narrowband data tables. It further provides examples of the data and its use.

aircraft communications↗
NASA NTRS1973

Study of control system effectiveness in alleviating vortex wake upsets.

The problem of an airplane being upset by encountering the vortex wake of a large transport on takeoff or landing is currently receiving considerable attention. This paper describes the technique and results of a study to assess the effectiveness of automatic control systems in alleviating vortex wake upsets. A six-degree-of-freedom nonlinear digital simulation was used for this purpose. The analysis included establishing the disturbance input due to penetrating a vortex wake from an arbitrary position and angle. Simulations were computed for both a general aviation airplane and a commercial jet transport. Dynamic responses were obtained for the penetrating aircraft with no augmentation and with various command augmentation systems. The results of this preliminary study indicate that it is feasible to use an automatic control system to alleviate vortex encounter upsets.

Johnson, W. A.↗
NASA NTRS1993

A MOS for all seasons

From a systems perspective, this paper examines the challenges of a single system to support multiple JPL space exploration missions and the need for unitary responsibility for the system. The focus is a Mission Operations System (MOS), which is effectively a mission management organization with direct authority over data system operations, command sequencing, flight operations control, data management, trajectory determination, telemetry and data acquisition, and spacecraft analysis. Stratagems for training and the approach to processes, procedures, and interfaces to facilitate the transition from the present situation to a truly multimission operational environment are developed. The outcome is a paradigm for a MOS that is achievable, that can effectively support multiple projects, and that can take advantage of technological changes without perturbing the entire system.

Bryant, Larry↗
NASA NTRS1988

Design of the unmanned Multiple Exploratory Probe System (MEPS) for Mars observations

The unmanned Multiple Exploratory Probe System (MEPS) is designed for Mars observations in preparation for manned missions to the planet early in the 21st century. MEPS will test vehicle systems, provide important data about the Martian surface and atmosphere, and assist the planning of manned missions. This mission will be a precursor to the manned missions. MEPS will consist of six primary systems. A Command Information Center (CIC) will be employed as an onboard mission control, communications link, and observation post. The Space Transportation Main Engine (STME) will be used to provide the thrust for Earth-Mars transit following vehicle construction near the Space Station. A polar lander/Orbital Transfer Vehicle (OTV) will be deployed during transit to achieve a polar orbit about Mars. A secondary propulsion will be used to place MEPS into orbit about Mars; this system and the aerobrake will circularize the orbit. Following orbit circulation, a satellite will be deployed to observe the Martian surface and atmosphere and to study the space environment. Polar and equatorial lander systems will land on Mars with rovers to collect surface and atmospheric samples while on-board laboratories will provide initial sample study. Two solid rocket booster/payload vehicles will launch samples into a low Mars orbit. The OTV will rendezvous with each payload capsule and then transfer the samples to Earth for hands-on observation.

Source record↗
NASA NTRS1995

Industrial Protocols for Spacecraft Command and Control

A standard data interface for spacecraft and intelligent spacecraft devices will have a major impact on the cost of building and flying satellites. The Space Messaging Service is a key element in a proposed 'open' standard for Space Project Mission Operations Control Architecture. The rationale for a messaging service is examined. Selection of specifications are discussed. Modifications are proposed.

Spacecraft Ground Systems Command and Control Mess↗
NASA NTRS2013

System Administrator for LCS Development Sets

The Spaceport Command and Control System Project is creating a Checkout and Control System that will eventually launch the next generation of vehicles from Kennedy Space Center. KSC has a large set of Development and Operational equipment already deployed in several facilities, including the Launch Control Center, which requires support. The position of System Administrator will complete tasks across multiple platforms (Linux/Windows), many of them virtual. The Hardware Branch of the Control and Data Systems Division at the Kennedy Space Center uses system administrators for a variety of tasks. The position of system administrator comes with many responsibilities which include maintaining computer systems, repair or set up hardware, install software, create backups and recover drive images are a sample of jobs which one must complete. Other duties may include working with clients in person or over the phone and resolving their computer system needs. Training is a major part of learning how an organization functions and operates. Taking that into consideration, NASA is no exception. Training on how to better protect the NASA computer infrastructure will be a topic to learn, followed by NASA work polices. Attending meetings and discussing progress will be expected. A system administrator will have an account with root access. Root access gives a user full access to a computer system and or network. System admins can remove critical system files and recover files using a tape backup. Problem solving will be an important skill to develop in order to complete the many tasks.

Virtualizing in Linux↗
NASA NTRS2006

The 'Biologically-Inspired Computing' Column

The field of Biology changed dramatically in 1953, with the determination by Francis Crick and James Dewey Watson of the double helix structure of DNA. This discovery changed Biology for ever, allowing the sequencing of the human genome, and the emergence of a "new Biology" focused on DNA, genes, proteins, data, and search. Computational Biology and Bioinformatics heavily rely on computing to facilitate research into life and development. Simultaneously, an understanding of the biology of living organisms indicates a parallel with computing systems: molecules in living cells interact, grow, and transform according to the "program" dictated by DNA. Moreover, paradigms of Computing are emerging based on modelling and developing computer-based systems exploiting ideas that are observed in nature. This includes building into computer systems self-management and self-governance mechanisms that are inspired by the human body's autonomic nervous system, modelling evolutionary systems analogous to colonies of ants or other insects, and developing highly-efficient and highly-complex distributed systems from large numbers of (often quite simple) largely homogeneous components to reflect the behaviour of flocks of birds, swarms of bees, herds of animals, or schools of fish. This new field of "Biologically-Inspired Computing", often known in other incarnations by other names, such as: Autonomic Computing, Pervasive Computing, Organic Computing, Biomimetics, and Artificial Life, amongst others, is poised at the intersection of Computer Science, Engineering, Mathematics, and the Life Sciences. Successes have been reported in the fields of drug discovery, data communications, computer animation, control and command, exploration systems for space, undersea, and harsh environments, to name but a few, and augur much promise for future progress.

Hinchey, Mike↗
NASA NTRS1994

Feedback control laws for highly maneuverable aircraft

During the first half of the year, the investigators concentrated their efforts on completing the design of control laws for the longitudinal axis of the HARV. During the second half of the year they concentrated on the synthesis of control laws for the lateral-directional axes. The longitudinal control law design efforts can be briefly summarized as follows. Longitudinal control laws were developed for the HARV using mu synthesis design techniques coupled with dynamic inversion. An inner loop dynamic inversion controller was used to simplify the system dynamics by eliminating the aerodynamic nonlinearities and inertial cross coupling. Models of the errors resulting from uncertainties in the principal longitudinal aerodynamic terms were developed and included in the model of the HARV with the inner loop dynamic inversion controller. This resulted in an inner loop transfer function model which was an integrator with the modeling errors characterized as uncertainties in gain and phase. Outer loop controllers were then designed using mu synthesis to provide robustness to these modeling errors and give desired response to pilot inputs. Both pitch rate and angle of attack command following systems were designed. The following tasks have been accomplished for the lateral-directional controllers: inner and outer loop dynamic inversion controllers have been designed; an error model based on a linearized perturbation model of the inner loop system was derived; controllers for the inner loop system have been designed, using classical techniques, that control roll rate and Dutch roll response; the inner loop dynamic inversion and classical controllers have been implemented on the six degree of freedom simulation; and lateral-directional control allocation scheme has been developed based on minimizing required control effort.

Garrard, William L.↗
DOE OSTI2018

Space vehicle with customizable payload and docking station

A "black box" space vehicle solution may allow a payload developer to define the mission space and provide mission hardware within a predetermined volume and with predetermined connectivity. Components such as the power module, radios and boards, attitude determination and control system (ADCS), command and data handling (C&DH), etc. may all be provided as part of a "stock" (i.e., core) space vehicle. The payload provided by the payload developer may be plugged into the space vehicle payload section, tested, and launched without custom development of core space vehicle components by the payload developer. A docking station may facilitate convenient development and testing of the space vehicle while reducing handling thereof.

33 ADVANCED PROPULSION SYSTEMS↗
NASA NTRS2012

Automated Operations Development for Advanced Exploration Systems

Automated space operations command and control software development and its implementation must be an integral part of the vehicle design effort. The software design must encompass autonomous fault detection, isolation, recovery capabilities and also provide "single button" intelligent functions for the crew. Development, operations and safety approval experience with the Timeliner system onboard the International Space Station (ISS), which provided autonomous monitoring with response and single command functionality of payload systems, can be built upon for future automated operations as the ISS Payload effort was the first and only autonomous command and control system to be in continuous execution (6 years), 24 hours a day, 7 days a week within a crewed spacecraft environment. Utilizing proven capabilities from the ISS Higher Active Logic (HAL) System, along with the execution component design from within the HAL 9000 Space Operating System, this design paper will detail the initial HAL System software architecture and interfaces as applied to NASA's Habitat Demonstration Unit (HDU) in support of the Advanced Exploration Systems, Autonomous Mission Operations project. The development and implementation of integrated simulators within this development effort will also be detailed and is the first step in verifying the HAL 9000 Integrated Test-Bed Component [2] designs effectiveness. This design paper will conclude with a summary of the current development status and future development goals as it pertains to automated command and control for the HDU.

Haddock, Angie T.↗
DOE OSTI2021

Real-Time Dispatch With Secondary Frequency Regulation: A Pathway to Consider Intra-Interval Fluctuations

Real-time dispatch balances the power demand with minimized operating costs. For the current dispatch model, the demand is assumed to be constant within a time interval, while the intra-interval power balance is left to frequency regulation. Based on practical experience and simulations, this behavior may lead to insufficient frequency regulation and uneconomic regulation costs considering the increase in intra-interval fluctuations caused by renewables. Here, a real-time dispatch method with secondary frequency regulation behaviors is proposed. Without changing the interval of the real-time dispatch command, the system regulation mileage and intra-interval generation adjustment are explicitly formulated in a mixed-integer optimization model. To reduce the computational burden, an efficient two-stage calculation method is proposed. With practical utility data, this article finds that the proposed method can effectively improve the system frequency performance with the subminute net load forecasting curve obtained by an off-the-shelf forecasting approach. Time-domain simulations in IEEE and practical utility systems validate the effectiveness of the proposed method in terms of the frequency performance and total operating costs.

24 POWER TRANSMISSION AND DISTRIBUTION↗