SEARCH · Engineering Papers

Results for “Computer Programming and software”

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.

SourceResearch connectionFrom yearThrough year

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

At least 1,549 records · Page 86

All sources NASA NTRS DOE OSTI

NASA NTRS1975

Development of a unified guidance system for geocentric transfer

A method is presented for open loop guidance of a solar electric propulsion spacecraft to geosynchronous orbit. The method consists of determining the thrust vector profiles on the ground with an optimization computer program, and performing updates based on the difference between the actual trajectory and that predicted with a precision simulation computer program. The motivation for performing the guidance analysis during the mission planning phase is discussed, and a spacecraft design option that employs attitude orientation constraints is presented. The improvements required in both the optimization program and simulation program are set forth, together with the efforts to integrate the programs into the ground support software for the guidance system.

Cake, J. E.↗

NASA NTRS1975

HAL/SM language specification

A programming language is presented for the flight software of the NASA Space Shuttle program. It is intended to satisfy virtually all of the flight software requirements of the space shuttle. To achieve this, it incorporates a wide range of features, including applications-oriented data types and organizations, real time control mechanisms, and constructs for systems programming tasks. It is a higher order language designed to allow programmers, analysts, and engineers to communicate with the computer in a form approximating natural mathematical expression. Parts of the English language are combined with standard notation to provide a tool that readily encourages programming without demanding computer hardware expertise. Block diagrams and flow charts are included. The semantics of the language is discussed.

Williams, G. P. W., Jr.↗

NASA NTRS1982

Investigating tectonic and bathymetric features of the Indian Ocean using MAGSAT magnetic anomaly data

MAGSAT Investigator-B tapes were preprocessed by (1) removing all data points with obvious erroneous values and location errors; (2) removing smaller spikes (typically 15 nT or more), and deleting data tracks with fewer than 20 points; and (3) removing a linear trend from each track. The remaining data were recorded on tape for use by the equivalent source mapping (ESMAP) program which uses a least squares algorithm to fit the magnetization parameter of the grid of equivalent source dipoles in the crust to satellite data acquired at different times and locations. ESMAP was implemented on the TASC computing system and modified to read preprocessed MAGSAT tapes and interface with TASC plotting software. Some verification of the software was accomplished. Gridded 1-degree mean values of gravity anomaly and sea surface undulation computed from SEASAT radar altimeter were obtained and brought on line.

Lazarewicz, A. R.↗

NASA NTRS1983

Analytical redundancy management mechanization and flight data analysis for the F-8 digital fly-by-wire aircraft flight control sensors

The details are presented of an onboard digital computer algorithm designed to reliably detect and isolate the first failure in a duplex set of flight control sensors aboard the NASA F-8 digital fly-by-wire aircraft. The algorithm's successful flight test program is summarized, and specific examples are presented of algorithm behavior in response to software-induced signal faults, both with and without aircraft parameter modeling errors.

Deckert, J. C.↗

NASA NTRS1990

A knowledge-based approach to improving optimization techniques in system planning

A knowledge-based (KB) approach to improve mathematical programming techniques used in the system planning environment is presented. The KB system assists in selecting appropriate optimization algorithms, objective functions, constraints and parameters. The scheme is implemented by integrating symbolic computation of rules derived from operator and planner's experience and is used for generalized optimization packages. The KB optimization software package is capable of improving the overall planning process which includes correction of given violations. The method was demonstrated on a large scale power system discussed in the paper.

Momoh, J. A.↗

NASA NTRS1992

Robotic welding at the Marshall Space Flight Center

The Marshall Space Flight Center is developing welding and robotics technologies to improve manufacturing of space hardware. Commercial robots are used for these development programs, but they are teamed with advanced sensors, process controls, and computer simulation to form highly productive manufacturing systems. Application of welding robotics and controls to structural welding for the space shuttle and space station Freedom programs is addressed. Several advanced welding process sensors under development for application to space hardware are discussed, as well as the application of commercial robotic simulation software to provide offline programming.

Jones, Clyde S.↗

NASA NTRS1992

Rain rate instrument for deployment at sea, phase 2

This report describes, in detail, the SBIR Phase 2 contracting effort provided for by NASA Contract Number NAS8-38481 in which a prototype Rain Rate Sensor was developed. FWG Model RP101A is a fully functional rain rate and droplet size analyzing instrument. The RP101A is a fully functional rain rate and droplet size analyzing instrument. The RP101A consists of a fiber optic probe containing a 32-fiber array connected to an electronic signal processor. When interfaced to an IBM compatible personal computer and configured with appropriate software, the RP101A is capable of measuring rain rates and particles ranging in size from around 300 microns up to 6 to 7 millimeters. FWG Associates, Inc. intends to develop a production model from the prototype and continue the effort under NASA's SBIR Phase 3 program.

Steele, Jimmy W.↗

NASA NTRS2000

The NASA IVHM Technology Experiment for X-37

The NASA IVHM (Integrated Vehicle Health Management) technology experiment for X-37 is presented. The goals and objectives of this program are: to reduce cost and increase reliability of space transportation; to demonstrate benefits of in-flight IVHM to the operation of a Reusable Launch Vehicle; to advance this IVHM technology to Technology Readiness Level approx. 7 within a flight environment; and to operate IVHM software on the Vehicle Management Computer. The following sections are included: Background (X-37 & Livingstone), Livingstone model example from DS-1, Experiment overview, X-37 IVHM scope, Stanley interface to livingstone model, Right ruddervator actuator, Motor state diagram, inferred nominal state, and X-37 informed maintenance experiment.

Source record↗

NASA NTRS2011

Directed Incremental Symbolic Execution

The last few years have seen a resurgence of interest in the use of symbolic execution -- a program analysis technique developed more than three decades ago to analyze program execution paths. Scaling symbolic execution and other path-sensitive analysis techniques to large systems remains challenging despite recent algorithmic and technological advances. An alternative to solving the problem of scalability is to reduce the scope of the analysis. One approach that is widely studied in the context of regression analysis is to analyze the differences between two related program versions. While such an approach is intuitive in theory, finding efficient and precise ways to identify program differences, and characterize their effects on how the program executes has proved challenging in practice. In this paper, we present Directed Incremental Symbolic Execution (DiSE), a novel technique for detecting and characterizing the effects of program changes. The novelty of DiSE is to combine the efficiencies of static analysis techniques to compute program difference information with the precision of symbolic execution to explore program execution paths and generate path conditions affected by the differences. DiSE is a complementary technique to other reduction or bounding techniques developed to improve symbolic execution. Furthermore, DiSE does not require analysis results to be carried forward as the software evolves -- only the source code for two related program versions is required. A case-study of our implementation of DiSE illustrates its effectiveness at detecting and characterizing the effects of program changes.

Person, Suzette↗

NASA NTRS2011

DAQ: Software Architecture for Data Acquisition in Sounding Rockets

A multithreaded software application was developed by Jet Propulsion Lab (JPL) to collect a set of correlated imagery, Inertial Measurement Unit (IMU) and GPS data for a Wallops Flight Facility (WFF) sounding rocket flight. The data set will be used to advance Terrain Relative Navigation (TRN) technology algorithms being researched at JPL. This paper describes the software architecture and the tests used to meet the timing and data rate requirements for the software used to collect the dataset. Also discussed are the challenges of using commercial off the shelf (COTS) flight hardware and open source software. This includes multiple Camera Link (C-link) based cameras, a Pentium-M based computer, and Linux Fedora 11 operating system. Additionally, the paper talks about the history of the software architecture's usage in other JPL projects and its applicability for future missions, such as cubesats, UAVs, and research planes/balloons. Also talked about will be the human aspect of project especially JPL's Phaeton program and the results of the launch.

Ahmad, Mohammad↗

NASA NTRS1983

F100 Multivariable Control Synthesis Program. Computer Implementation of the F100 Multivariable Control Algorithm

As turbofan engines become more complex, the development of controls necessitate the use of multivariable control techniques. A control developed for the F100-PW-100(3) turbofan engine by using linear quadratic regulator theory and other modern multivariable control synthesis techniques is described. The assembly language implementation of this control on an SEL 810B minicomputer is described. This implementation was then evaluated by using a real-time hybrid simulation of the engine. The control software was modified to run with a real engine. These modifications, in the form of sensor and actuator failure checks and control executive sequencing, are discussed. Finally recommendations for control software implementations are presented.

Soeder, J. F.↗

NASA NTRS1989

Hierarchical Ada robot programming system (HARPS)- A complete and working telerobot control system based on the NASREM model

HARPS is a telerobot control system that can perform some simple but useful tasks. This capability is demonstrated by performing the ORU exchange demonstration. HARPS is based on NASREM (NASA Standard Reference Model). All software is developed in Ada, and the project incorporates a number of different CASE (computer-aided software engineering) tools. NASREM was found to be a valid and useful model for building a telerobot control system. Its hierarchical and distributed structure creates a natural and logical flow for implementing large complex robust control systems. The ability of Ada to create and enforce abstraction enhanced the implementation of such control systems.

Leake, Stephen↗

NASA NTRS1981

The Aerospace Vehicle Interactive Design system

The aerospace vehicle interactive design (AVID) is a computer aided design that was developed for the conceptual and preliminary design of aerospace vehicles. The AVID system evolved from the application of several design approaches in an advanced concepts environment in which both mission requirements and vehicle configurations are continually changing. The basic AVID software facilitates the integration of independent analysis programs into a design system where the programs can be executed individually for analysis or executed in groups for design iterations and parametric studies. Programs integrated into an AVID system for launch vehicle design include geometry, aerodynamics, propulsion, flight performance, mass properties, and economics.

Wilhite, A. W.↗

NASA NTRS1990

Software For Three-Dimensional Space-Shuttle Imagery

Flight Dynamics/Space Transportation System Three-Dimensional Monitor System (3-D Mon) is real-time graphical mission-monitoring software tool. Main objective to compute and display realistic three-dimensional solid model image of Space Shuttle, remote-manipulator system, payload, and surroundings from real-time Space Shuttle telemetry data. Ability to support spacecraft other than Space Shuttle also incorporated. Display shows almost any desired perspective. Written in C programming language.

Pittarelli, Ernest J.↗

NASA NTRS1990

A concurrent distributed system for aircraft tactical decision generation

A research program investigating the use of AI techniques to aid in the development of a tactical decision generator (TDG) for within visual range (WVR) air combat engagements is discussed. The application of AI programming and problem-solving methods in the development and implementation of a concurrent version of the computerized logic for air-to-air warfare simulations (CLAWS) program, a second-generation TDG, is presented. Concurrent computing environments and programming approaches are discussed, and the design and performance of prototype concurrent TDG system (Cube CLAWS) are presented. It is concluded that the Cube CLAWS has provided a useful testbed to evaluate the development of a distributed blackboard system. The project has shown that the complexity of developing specialized software on a distributed, message-passing architecture such as the Hypercube is not overwhelming, and that reasonable speedups and processor efficiency can be achieved by a distributed blackboard system. The project has also highlighted some of the costs of using a distributed approach to designing a blackboard system.

Mcmanus, John W.↗

NASA NTRS1991

Continuation of research into language concepts for the mission support environment

A concept for a more intuitive and graphically based Computation (Comp) Builder was developed. The Graphical Comp Builder Prototype was developed, which is an X Window based graphical tool that allows the user to build Comps using graphical symbols. Investigation was conducted to determine the availability and suitability of the Ada programming language for the development of future control center type software. The Space Station Freedom Project identified Ada as the desirable programming language for the development of Space Station Control Center software systems.

Source record↗

NASA NTRS1994

Adding intelligent services to an object oriented system

As today's software becomes increasingly complex, the need grows for intelligence of one sort or another to becomes part of the application, often an intelligence that does not readily fit the paradigm of one's software development. There are many methods of developing software, but at this time, the most promising is the object oriented (OO) method. This method involves an analysis to abstract the problem into separate 'objects' that are unique in the data that describe them and the behavior that they exhibit, and eventually to convert this analysis into computer code using a programming language that was designed (or retrofitted) for OO implementation. This paper discusses the creation of three different applications that are analyzed, designed, and programmed using the Shlaer/Mellor method of OO development and C++ as the programming language. All three, however, require the use of an expert system to provide an intelligence that C++ (or any other 'traditional' language) is not directly suited to supply. The flexibility of CLIPS permitted us to make modifications to it that allow seamless integration with any of our applications that require an expert system. We illustrate this integration with the following applications: (1) an after action review (AAR) station that assists a reviewer in watching a simulated tank battle and developing an AAR to critique the performance of the participants in the battle; (2) an embedded training system and over-the-shoulder coach for howitzer crewmen; and (3) a system to identify various chemical compounds from their infrared absorption spectra.

Robideaux, Bret R.↗

NASA NTRS1994

NASA-OAI HPCCP K-12 Program

The NASA-OAI High Performance Communication and Computing K- 12 School Partnership program has been completed. Cleveland School of the Arts, Empire Computech Center, Grafton Local Schools and the Bug O Nay Ge Shig School have all received network equipment and connections. Each school is working toward integrating computer and communications technology into their classroom curriculum. Cleveland School of the Arts students are creating computer software. Empire Computech Center is a magnet school for technology education at the elementary school level. Grafton Local schools is located in a rural community and is using communications technology to bring to their students some of the same benefits students from suburban and urban areas receive. The Bug O Nay Ge Shig School is located on an Indian Reservation in Cass Lake, MN. The students at this school are using the computer to help them with geological studies. A grant has been issued to the friends of the Nashville Library. Nashville is a small township in Holmes County, Ohio. A community organization has been formed to turn their library into a state of the art Media Center. Their goal is to have a place where rural students can learn about different career options and how to go about pursuing those careers. Taylor High School in Cincinnati, Ohio was added to the schools involved in the Wind Tunnel Project. A mini grant has been awarded to Taylor High School for computer equipment. The computer equipment is utilized in the school's geometry class to computationally design objects which will be tested for their aerodynamic properties in the Barberton Wind Tunnel. The students who create the models can view the test in the wind tunnel via desk top conferencing. Two teachers received stipends for helping with the Regional Summer Computer Workshop. Both teachers were brought in to teach a session within the workshop. They were selected to teach the session based on their expertise in particular software applications.

Source record↗