SEARCH · Engineering Papers
Results for “task programming”
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.
Debugging tasked Ada programs
The applications for which Ada was developed require distributed implementations of the language and extensive use of tasking facilities. Debugging and testing technology as it applies to parallel features of languages currently falls short of needs. Thus, the development of embedded systems using Ada pose special challenges to the software engineer. Techniques for distributing Ada programs, support for simulating distributed target machines, testing facilities for tasked programs, and debugging support applicable to simulated and to real targets all need to be addressed. A technique is presented for debugging Ada programs that use tasking and it describes a debugger, called AdaTAD, to support the technique. The debugging technique is presented together with the use interface to AdaTAD. The component of AdaTAD that monitors and controls communication among tasks was designed in Ada and is presented through an example with a simple tasked program.
Materials processing in space program tasks-supplement
An overview of the program scope for managers and scientists in industry, university, and government communities is provided. An introductory description of the program, its history, strategy, and overall goals; identification of the organizational structures and people involved; and a description of each research task, together with a list of recent publications are included. The tasks are grouped into six categories: crystal growth; solidification of metals, alloys, and composites; fluids, transports, and chemical processes; and ultrahigh vacuum and containerless processing technologies; combustion experiments; and experimental technology.
Applications of artificial intelligence to mission planning
The following subject areas are covered: object-oriented programming task; rule-based programming task; algorithms for resource allocation; connecting a Symbolics to a VAX; FORTRAN from Lisp; trees and forest task; software data structure conversion; software functionality modifications and enhancements; portability of resource allocation to a TI MicroExplorer; frontier of feasibility software system; and conclusions.
Corrosion Prevention in Copper Combustion Chamber Liners of Liquid Oxygen/Methane Booster Engines
Prior research conducted by United Technologies Research Center and Rockwell International Rocketdyne Division encountered severe copper corrosion while flowing hydrocarbon fuels through copper cooling tubes. These experimental results have very important implications for the development of low-cost, regeneratively cooled, oxygen/hydrocarbon bipropellant booster engines. Aerojet TechSystems undertook a program sponsored by NASA/Lewis Research Center in 1986 with two objectives: (1) to define the corrosive interaction process that occurs between hydrocarbon fuels and copper combustion chamber liner materials, using both static and dynamic test methods, and (2) to identify and demonstrate protective measures against this corrosive process. The results of the first program task demonstrated that the most damaging corrosive process was caused by trace amounts of sulfur-containing impurities in the hydrocarbon fuel which react with the copper chamber liner material to form cuprous sulfide (Cu2S), as reported in Paper No. AlAA 88-3215. Experiments were conducted which demonstrated this corrosive process with Mil-Spec RP-1, propane, and methane fuels in contact with OFHC, NASA-Z, and ZrCu coppers. The preliminary results of the second program task demonstrated that electrodeposited gold and platinum coatings held promise of preventing corrosion of copper chamber liners by methane contaminated with sulfur-containing impurities, as reported in Paper No. AIAA 89-2738. Experiments were conducted which demonstrated greatly reduced corrosion of copper by hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) as measured impurities in methane. This paper presents the concluding, confirmatory results from the second program task. The efficacy of a protective gold coating on NASA-Z copper cooling channel walls was conclusively demonstrated. Tests were conducted in the Aerojet Carbothermal Test Facility which provide realistic simulations of booster engine cooling channel conditions such as temperature, pressure, flow velocity, and heat flux. Dynamic test series were performed with methane containing 5 and 10 ppm (by volume) hydrogen sulfide. Gold-plated and unplated copper alloy specimens were evaluated. The tests demonstrated that gold coatings were effective in preventing corrosion of the copper. Posttest metallographic examinations of the unplated specimens showed severe corrosion as a result of reaction with the sulfur containing contaminant in the fuel. In contrast, posttest metallographic examination of the gold-coated specimens showed no corrosion under similar operating conditions. The findings from metallurgical and chemical analyses of the copper specimens, chemical analysis of the methane, and description of all test conditions are provided. Conclusions are reached as to the efficacy of the plating methods and the effectiveness of the metal coatings in the prevention of corrosion in hydrocarbon-fueled booster engine combustion chamber liners.
Silicon material task - Low cost solar array project /JPL/DOE/
The paper describes the silicon material task of the low-cost solar array project, which has the objective of establishing a silicon production capability equivalent to 500 mW per year at a price less than 10 dollars/kg (1975 dollars) in 1986. The task program is divided into four phases: technical feasibility, scale-up studies (the present phase), experimental process system development units, and implementation of large-scale production plants, and it involves the development of processes for two groups of materials, that is, semiconductor grade and solar cell grade. In addition, the effects of impurities on solar cell performance are being investigated. Attention is given to problem areas of the task program, such as environmental protection, material compatibility between the reacting chemicals and materials of construction of the equipment, and waste disposal.
Space station data system analysis/architecture study. Task 5: Program plan
Cost estimates for both the on-board and ground segments of the Space Station Data System (SSDS) are presented along with summary program schedules. Advanced technology development recommendations are provided in the areas of distributed data base management, end-to-end protocols, command/resource management, and flight qualified artificial intelligence machines.
NASA Aerospace Flight Battery Systems Program - Issues and actions
The NASA Aerospace Flight Battery Systems Program task status is reviewed. Major tasks incorporated in the program are battery systems, secondary batteries, and primary batteries.
Artificial intelligence programming languages for computer aided manufacturing
Eight Artificial Intelligence programming languages (SAIL, LISP, MICROPLANNER, CONNIVER, MLISP, POP-2, AL, and QLISP) are presented and surveyed, with examples of their use in an automated shop environment. Control structures are compared, and distinctive features of each language are highlighted. A simple programming task is used to illustrate programs in SAIL, LISP, MICROPLANNER, and CONNIVER. The report assumes reader knowledge of programming concepts, but not necessarily of the languages surveyed.
Development of a task-level robot programming and simulation system
An ongoing project in developing a Task-Level Robot Programming and Simulation System (TARPS) is discussed. The objective of this approach is to design a generic TARPS that can be used in a variety of applications. Many robotic applications require off-line programming, and a TARPS is very useful in such applications. Task level programming is object centered in that the user specifies tasks to be performed instead of robot paths. Graphics simulation provides greater flexibility and also avoids costly machine setup and possible damage. A TARPS has three major modules: world model, task planner and task simulator. The system architecture, design issues and some preliminary results are given.
Small Engine Technology (SET) - Task 4, Regional Turboprop/Turbofan Engine Advanced Combustor Study
Under the SET Program Task 4 - Regional Turboprop/Turbofan Engine Advanced Combustor Study, a total of ten low-emissions combustion system concepts were evaluated analytically for three different gas turbine engine geometries and three different levels of oxides of nitrogen (NOx) reduction technology, using an existing AlliedSignal three-dimensional (3-D) Computational Fluid Dynamics (CFD) code to predict Landing and Takeoff (LTO) engine cycle emission values. A list of potential Barrier Technologies to the successful implementation of these low-NOx combustor designs was created and assessed. A trade study was performed that ranked each of the ten study configurations on the basis of a number of manufacturing and durability factors, in addition to emissions levels. The results of the trade study identified three basic NOx-emissions reduction concepts that could be incorporated in proposed follow-on combustor technology development programs aimed at demonstrating low-NOx combustor hardware. These concepts are: high-flow swirlers and primary orifices, fuel-preparation cans, and double-dome swirlers.
AUTOSIM: An automated repetitive software testing tool
AUTOSIM is a software tool which automates the repetitive run testing of software. This tool executes programming tasks previously performed by a programmer with one year of programming experience. Use of the AUTOSIM tool requires a knowledge base containing information about known faults, code fixes, and the fault diagnosis-correction process. AUTOSIM can be considered as an expert system which replaces a low level of programming expertise. Reference information about the design and implementation of the AUTOSIM software test tool provides flowcharts to assist in maintaining the software code and a description of how to use the tool.
Task-level robot programming: Integral part of evolution from teleoperation to autonomy
An explanation is presented of task-level robot programming and of how it differs from the usual interpretation of task planning for robotics. Most importantly, it is argued that the physical and mathematical basis of task-level robot programming provides inherently greater reliability than efforts to apply better known concepts from artificial intelligence (AI) to autonomous robotics. Finally, an architecture is presented that allows the integration of task-level robot programming within an evolutionary, redundant, and multi-modal framework that spans teleoperation to autonomy.
Processor for the UNIVAC 1100 series
MBASIC, advanced version of BASIC, is high-level interactive computer language designed to minimize time required for user to program task for computer execution. Language usually results in shorter and simpler programs that are easier to write and understand.
Software for Secondary-School Learning About Robotics
The ROVer Ranch is an interactive computer program designed to help secondary-school students learn about space-program robotics and related basic scientific concepts by involving the students in simplified design and programming tasks that exercise skills in mathematics and science. The tasks involve building simulated robots and then observing how they behave. The program furnishes (1) programming tools that a student can use to assemble and program a simulated robot and (2) a virtual three-dimensional mission simulator for testing the robot. First, the ROVer Ranch presents fundamental information about robotics, mission goals, and facts about the mission environment. On the basis of this information, and using the aforementioned tools, the student assembles a robot by selecting parts from such subsystems as propulsion, navigation, and scientific tools, the student builds a simulated robot to accomplish its mission. Once the robot is built, it is programmed and then placed in a three-dimensional simulated environment. Success or failure in the simulation depends on the planning and design of the robot. Data and results of the mission are available in a summary log once the mission is concluded.
XPI: The Xanadu Parameter Interface
XPI is a table driven parameter interface which greatly simplifies both command driven programs such as BROWSE and XIMAGE as well as stand alone single-task programs. It moves all of the syntax and semantic parsing of commands and parameters out of the users code into common code and externally defined tables. This allows the programmer to concentrate on writing the code unique to the application rather than reinventing the user interface and for external graphical interfaces to interface with no changes to the command driven program. XPI also includes a compatibility library which allows programs written using the IRAF host interface (Mandel and Roll) to use XPI in place of the IRAF host interface.
Research and technology: 1985 annual report of the Lyndon B. Johnson Space Center
Johnson Space Center accomplishments in new and advanced concepts during 1985 are highlighted. Included are research funded by the Office of Aeronautics and Space Technology; Solar System Exploration and Life Sciences research funded by the Office of Space Sciences and Applications; and Advanced Programs tasks funded by the Office of Space Flight. Summary sections describing the role of the Johnson Space Center in each program are followed by one-page descriptions of significant projects. Descriptions are suitable for external consumption, free of technical jargon, and illustrated to increase ease of comprehension.