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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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Formalizing structured file services for the data storage and retrieval subsystem of the data management system for Spacestation Freedom

A brief example of the use of formal methods techniques in the specification of a software system is presented. The report is part of a larger effort targeted at defining a formal methods pilot project for NASA. One possible application domain that may be used to demonstrate the effective use of formal methods techniques within the NASA environment is presented. It is not intended to provide a tutorial on either formal methods techniques or the application being addressed. It should, however, provide an indication that the application being considered is suitable for a formal methods by showing how such a task may be started. The particular system being addressed is the Structured File Services (SFS), which is a part of the Data Storage and Retrieval Subsystem (DSAR), which in turn is part of the Data Management System (DMS) onboard Spacestation Freedom. This is a software system that is currently under development for NASA. An informal mathematical development is presented. Section 3 contains the same development using Penelope (23), an Ada specification and verification system. The complete text of the English version Software Requirements Specification (SRS) is reproduced in Appendix A.

Jamsek, Damir A.↗
NASA NTRS1991

On-board fault management for autonomous spacecraft

The dynamic nature of the Cargo Transfer Vehicle's (CTV) mission and the high level of autonomy required mandate a complete fault management system capable of operating under uncertain conditions. Such a fault management system must take into account the current mission phase and the environment (including the target vehicle), as well as the CTV's state of health. This level of capability is beyond the scope of current on-board fault management systems. This presentation will discuss work in progress at TRW to apply artificial intelligence to the problem of on-board fault management. The goal of this work is to develop fault management systems. This presentation will discuss work in progress at TRW to apply artificial intelligence to the problem of on-board fault management. The goal of this work is to develop fault management systems that can meet the needs of spacecraft that have long-range autonomy requirements. We have implemented a model-based approach to fault detection and isolation that does not require explicit characterization of failures prior to launch. It is thus able to detect failures that were not considered in the failure and effects analysis. We have applied this technique to several different subsystems and tested our approach against both simulations and an electrical power system hardware testbed. We present findings from simulation and hardware tests which demonstrate the ability of our model-based system to detect and isolate failures, and describe our work in porting the Ada version of this system to a flight-qualified processor. We also discuss current research aimed at expanding our system to monitor the entire spacecraft.

Fesq, Lorraine M.↗
NASA NTRS1992

Recent developments at the Goddard Engineering Test Bed

Work on the Flight Telerobotic Service (FTS) since that reported in Leake (1991) is examined, and initial work on a Hubble servicing mission is outlined. A state-of-the-art force reflecting teleoperation system that uses torque control at the joints of the slave manipulator has been implemented. The master rate/slave damper mode proposed by Langley has proved to be a very efficient operational mode, allowing force reflection ratios up to one to one. A software architecture for real-time Ada robotics systems has been proposed, and implementation has been launched. This architecture builds on the lessons learned from NASA Standard Reference Model Architecture and the prototype FTS effort. The Capaciflector sensor has been integrated into the system, and it has been used to perform a basic berthing task autonomously.

Leake, Stephen↗
NASA NTRS1993

System architecture for asynchronous multi-processor robotic control system

The architecture for the Modular Telerobot Task Execution System (MOTES) as implemented in the Supervisory Telerobotics (STELER) Laboratory is described. MOTES is the software component of the remote site of a local-remote telerobotic system which is being developed for NASA for space applications, in particular Space Station Freedom applications. The system is being developed to provide control and supervised autonomous control to support both space based operation and ground-remote control with time delay. The local-remote architecture places task planning responsibilities at the local site and task execution responsibilities at the remote site. This separation allows the remote site to be designed to optimize task execution capability within a limited computational environment such as is expected in flight systems. The local site task planning system could be placed on the ground where few computational limitations are expected. MOTES is written in the Ada programming language for a multiprocessor environment.

Steele, Robert D.↗
NASA NTRS1992

Ground-remote control for space station telerobotics with time delay

The study proposes a ground-remote telerobot control architecture which could be used for control of Space Station Freedom manipulators. The architecture provides two local-site operator control stations representing potential earth-based and remote Space Station-based operator control stations. A unified control system at the remote site provides autonomous, shared, and teleoperation control for single-and dual-arm task execution. An operational laboratory system which demonstrates the feasibility of various technologies in the proposed architecture, including teleoperation, shared control, and supervised autonomy, is described. Enhancements to the system currently under development, including remote site implementation in Ada, integration and control of a redundant 7-DOF manipulator, and local site advanced operator aids, are also described.

Backes, Paul G.↗
NASA NTRS1994

Maximizing Performance Of A Telerobot With Minimal Software

Control software system of seven-degree-of-freedom telerobot designed to elicit maximum performance from minimal, fixed-software computer at remote robot site. Includes multiple control modules, each providing parameter-driven control of specified aspect of behavior of telerobot. Software system runs in Ada language on multiple 68020 processors or potentially on single central processing unit. Conceived for use in outer space, also proves useful in underwater construction and inspection, handling of materials in nuclear facilities, and cleaning up hazardous materials.

Backes, Paul G.↗
NASA NTRS1994

Personal Computer Monitors Instrumentation Bus

IBM-compatible personal computer used instead of logic analyzer or other special instrument to monitor IEEE-488 interface data bus that interconnects various pieces of laboratory equipment. Needed is short program for computer, commercial general-purpose interface bus circuit card, and adapter cable to link card to bus. Software available in Ada or Quick Basic language.

Conroy, Bruce L.↗
NASA NTRS1994

Software For Computer-Aided Design Of Control Systems

Computer Aided Engineering System (CAESY) software developed to provide means to evaluate methods for dealing with users' needs in computer-aided design of control systems. Interpreter program for performing engineering calculations. Incorporates features of both Ada and MATLAB. Designed to be flexible and powerful. Includes internally defined functions, procedures and provides for definition of functions and procedures by user. Written in C language.

Wette, Matthew↗
NASA NTRS1988

Research review for information management

The goal of RICIS research in information management is to apply currently available technology to existing problems in information management. Research projects include the following: the Space Business Research Center (SBRC), the Management Information and Decision Support Environment (MIDSE), and the investigation of visual interface technology. Several additional projects issued reports. New projects include the following: (1) the AdaNET project to develop a technology transfer network for software engineering and the Ada programming language; and (2) work on designing a communication system for the Space Station Project Office at JSC. The central aim of all projects is to use information technology to help people work more productively.

Bishop, Peter C.↗
NASA NTRS1990

OMS event evaluator and scheduler

An Operations Management System (OMS) is being designed for Space Station Freedom to improve productivity, reliability, and safety while reducing operations and maintenance costs. Central to the concept is a short term plan containing mixes of man-readable and machine-executable procedures used in an environment of distributed processing and execution. An OMS event evaluator to check upcoming short-term plan events for validity of execution is under development. The first version checks time and resource constraints against operational conditions for current or expected stations. In work are the handling of environmental and other operational constraints, as well as detailed modeling of resources and station operational states. The Ada Program also has the ability to reschedule all or part of the events.

Eckelkamp, Richard E.↗
NASA NTRS1992

Proceedings of the Seventeenth Annual Software Engineering Workshop

Proceedings of the Seventeenth Annual Software Engineering Workshop are presented. The software Engineering Laboratory (SEL) is an organization sponsored by NASA/Goddard Space Flight Center and created to investigate the effectiveness of software engineering technologies when applied to the development of applications software. Topics covered include: the Software Engineering Laboratory; process measurement; software reuse; software quality; lessons learned; and is Ada dying.

Source record↗
NASA NTRS1993

Transportable Applications Environment (TAE) Tenth Users' Conference

Conference proceedings are represented in graphic visual-aid form. Presentation and panel discussion topics include user experiences with C++ and Ada; the design and interaction of the user interface; the history and goals of TAE; commercialization and testing of TAE Plus; Computer-Human Interaction Models (CHIMES); data driven objects; item-to-item connections and object dependencies; and integration with other software. There follows a list of conference attendees.

Rouff, Chris↗
NASA NTRS1993

In-flight simulation of high agility through active control: Taming complexity by design

The motivation for research into helicopter agility stems from the realization that marked improvements relative to current operational types are possible, yet there is a dearth of useful criteria for flying qualities at high performance levels. Several research laboratories are currently investing resources in developing second generation airborne rotorcraft simulators. The UK's focus has been the exploitation of agility through active control technology (ACT); this paper reviews the results of studies conducted to date. The conflict between safety and performance in flight research is highlighted and the various forms of safety net to protect against system failures are described. The role of the safety pilot, and the use of actuator and flight envelope limiting are discussed. It is argued that the deep complexity of a research ACT system can only be tamed through a requirement specification assembled using design principles and cast in an operational simulation form. Work along these lines conducted at DRA is described, including the use of the Jackson System Development method and associated Ada simulation.

Padfield, Gareth D.↗
NASA NTRS1993

The geo-control system for station keeping and colocation of geostationary satellites

GeoControl is a compact but powerful and accurate software system for station keeping of single and colocated satellites, which has been developed at the German Space Operations Center. It includes four core modules for orbit determination (including maneuver estimation), maneuver planning, monitoring of proximities between colocated satellites, and interference and event prediction. A simple database containing state vector and maneuver information at selected epochs is maintained as a central interface between the modules. A menu driven shell utilizing form screens for data input serves as the central user interface. The software is written in Ada and FORTRAN and may be used on VAX workstations or mainframes under the VMS operating system.

Montenbruck, O.↗
NASA NTRS1993

Performance measures from the explorer platform berthing experiment

The Explorer Platform is a Modular Mission Spacecraft: it has several subunits that are designed to be replaced on orbit. The Goddard Space Flight Center Robotics Lab undertook an experiment to evaluate various robotic approaches to replacing one of the units; a large (approximately 1 meter by 1 meter by 0.5 meter) power box. The hardware consists of a Robotics Research Corporation K-1607 (RRC) manipulator mounted on a large gantry robot, a Kraft handcontroller for teleoperation of RRC, a Lightweight Servicing Tool (LST) mounted on the RRC, and an Explorer Platform mockup (EP) with a removable box (MMS) that has fixtures that mate with the LST. Sensors include a wrist wrench sensor on the RRC and Capaciflectors mounted on the LST and the MMS. There are also several cameras, but no machine vision is used. The control system for the RRC is entirely written by Goddard; it consists of Ada code on three Multibus I 386/387 CPU boards doing the real-time robot control, and C on a 386 PC processing Capaciflector data. The gantry is not moved during this experiment. The task is the exchange of the MMS; it is removed and replaced. This involves four basic steps: mating the LST to the MMS, demating the MMS from the EP, mating the MMS to the EP, and demating the LST form the MMS. Each of the mating steps must be preceeded by an alignment to bring the mechanical fixtures within their capture range. Two basic approaches to alignment are explored: teleoperation with the operator viewing thru cameras, and Capaciflector based autonomy. To evaluate the two alignment approaches, several runs were run with each approach and the final pose was recorded. Comparing this to the ideal alignment pose gives accuracy and repeatability data. In addition the wrenches exerted during the mating tasks were recorded; this gives information on how the alignment step affects the mating step. There are also two approaches to mating; teleoperation, and impedance based autonomy. The wrench data taken during mating using these two approaches is used to evaluate them. Section 2 describes the alignment results, section 3 describes the mating results, and finally Section 4 gives some conclusions.

Leake, Stephen↗
NASA NTRS1993

Fast gravity, gravity partials, normalized gravity, gravity gradient torque and magnetic field: Derivation, code and data

Derivation of first and second partials of the gravitational potential is given in both normalized and unnormalized form. Two different recursion formulas are considered. Derivation of a general gravity gradient torque algorithm which uses the second partial of the gravitational potential is given. Derivation of the geomagnetic field vector is given in a form that closely mimics the gravitational algorithm. Ada code for all algorithms that precomputes all possible data is given. Test cases comparing the new algorithms with previous data are given, as well as speed comparisons showing the relative efficiencies of the new algorithms.

Gottlieb, Robert G.↗
NASA NTRS1993

Annotated bibliography of Software Engineering Laboratory literature

This document is an annotated bibliography of technical papers, documents, and memorandums produced by or related to the Software Engineering Laboratory. Nearly 200 publications are summarized. These publications cover many areas of software engineering and range from research reports to software documentation. This document has been updated and reorganized substantially since the original version (SEL-82-006, November 1982). All materials have been grouped into eight general subject areas for easy reference: the Software Engineering Laboratory; the Software Engineering Laboratory: software development documents; software tools; software models; software measurement; technology evaluations; Ada technology; and data collection. This document contains an index of these publications classified by individual author.

Morusiewicz, Linda↗