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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

An integrated dexterous robotic testbed for space applications

An integrated dexterous robotic system was developed as a testbed to evaluate various robotics technologies for advanced space applications. The system configuration consisted of a Utah/MIT Dexterous Hand, a PUMA 562 arm, a stereo vision system, and a multiprocessing computer control system. In addition to these major subsystems, a proximity sensing system was integrated with the Utah/MIT Hand to provide capability for non-contact sensing of a nearby object. A high-speed fiber-optic link was used to transmit digitized proximity sensor signals back to the multiprocessing control system. The hardware system was designed to satisfy the requirements for both teleoperated and autonomous operations. The software system was designed to exploit parallel processing capability, pursue functional modularity, incorporate artificial intelligence for robot control, allow high-level symbolic robot commands, maximize reusable code, minimize compilation requirements, and provide an interactive application development and debugging environment for the end users. An overview is presented of the system hardware and software configurations, and implementation is discussed of subsystem functions.

Li, Larry C.↗
NASA NTRS1993

The Application of Microtechnology to Spacecraft On-Board Computing(abstract)

In this report, we will survey recent advances in chip packaging and stacking techniques that allow miniature computers to be developed for space applications. Several orders of magnitude reduction in mass, volume, and power consumption are possible using these techniques. Moreover, performance improvements can be achieved by increasing the scale of multiprocessing. Most importantly, long-term survivability can potentially be improved by increasing the level of redundancy and fault tolerance.

microtechnology computers multiprocessing packagin↗
NASA NTRS1968

Two-way digital driver/receiver uses one set of lines

Two-way /bilateral/ digital driver/receiver system using MOS circuits was designed for a multiprocess computer having several subsystems at relatively close locations. The system requires only a single set of communication lines between subsystems, thus achieving lower cost with increased reliability.

Burnett, G. J.↗
NASA NTRS1971

Spaceborne computer executive routine functional design specification. Volume 2: Computer executive design for space station/base

The computer executive functional system design concepts derived from study of the Space Station/Base are presented. Information Management System hardware configuration as directly influencing the executive design is reviewed. The hardware configuration and generic executive design requirements are considered in detail in a previous report (System Configuration and Executive Requirements Specifications for Reusable Shuttle and Space Station/Base, 9/25/70). This report defines basic system primitives and delineates processes and process control. Supervisor states are considered for describing basic multiprogramming and multiprocessing systems. A high-level computer executive including control of scheduling, allocation of resources, system interactions, and real-time supervisory functions is defined. The description is oriented to provide a baseline for a functional simulation of the computer executive system.

Kennedy, J. R.↗
NASA NTRS1972

The effect of modifying response and performance feedback parameters on the CNV in humans

The effect on the CNV of sustained and delayed motor response with the dominant and nondominant hand in the presence and absence of visual performance feedback, was studied in 15 male adults. Monopolar scalp recordings were obtained at Fz, Cz, Pz, and bilaterally over the motor hand area. Results indicated that the magnitude of the CNV was greater in the delayed than sustained response task, greater in the presence than absence of feedback, and greater over the motor hand area contralateral to movement. Frontal CNV habituated in the sustained, but not the delayed response task, suggested that frontal negative variations in the former case signify an orienting response to novelty or uncertainty. The absence of habituation in the delay condition was interpreted in terms of the motor inhibitory function of frontal association cortex. Performance feedback appeared to enhance CNV indirectly by increasing the motivation of subjects. A multiprocess conception of CNV was proposed in which vortex-negative slow potentials reflect a multiplicity of psychophysiological processes occurring at a variety of cortical and subcortical locations in the brain preparatory to a motor or mental action.

Otto, D. A.↗
NASA NTRS1972

Multi-processing control system for the SEL 840MP (MPCS/1) users guide. Volume 1: Programming guide

A programmer's manual is presented for the SEL 840MP multiprocessing control system MPCS. The topics discussed include task control; defining displays; MPCS calls for task control functions; MPCS calls and system interfaces for display functions; MPCS calls for input/output functions and services, file management, and utility services; and MPCS assembly language call sequence summary.

Source record↗
NASA NTRS1972

Engineering study for the functional design of a multiprocessor system

The results are presented of a study to generate a functional system design of a multiprocessing computer system capable of satisfying the computational requirements of a space station. These data management system requirements were specified to include: (1) real time control, (2) data processing and storage, (3) data retrieval, and (4) remote terminal servicing.

Miller, J. S.↗
NASA NTRS1973

Design of a modular digital computer system

A design tradeoff study is reported for a modular spaceborne computer system that is responsive to many mission types and phases. The computer uses redundancy to maximize reliability, and multiprocessing to maximize processing capacity. Fault detection and recovery features provide optimal reliability.

Source record↗
NASA NTRS1979

Integrated testing and verification system for research flight software

The MUST (Multipurpose User-oriented Software Technology) program is being developed to cut the cost of producing research flight software through a system of software support tools. An integrated verification and testing capability was designed as part of MUST. Documentation, verification and test options are provided with special attention on real-time, multiprocessing issues. The needs of the entire software production cycle were considered, with effective management and reduced lifecycle costs as foremost goals.

Taylor, R. N.↗
NASA NTRS1978

Processing by data and program blocks

A processing system is presented that implements simultaneously the efficiency of the special-purpose processor and the total applicability of the general-purpose computer - characteristics commonly thought of as being mutually exclusive. This is achieved through specializing the machine by programming the hardware structure, rather than by adding software systems to it. Data are organized in circulating pages which form a multiplicity of local dynamic memories for each process. Programs are made up of modules, each describing a transient special-purpose machine. A characteristic of this approach is that the processes are data-driven, rather than program-driven. The programming language presents significant flexibility and efficiency in modeling certain classes of problems, and it may be of interest as an implementation model in a broader context. Applications to real-time processing of radar signals are reported. The relevance of characteristics of this system to problems in multiprogramming and multiprocessing systems is discussed.

Schaffner, M. R.↗
NASA NTRS1980

Asynchronous interactive control systems

A class of interactive control systems is derived by generalizing interactive manipulator control systems. The general structural properties of such systems are discussed and an appropriate general software implementation is proposed. This is based on the fact that tasks of interactive control systems can be represented as a network of a finite set of actions which have specific operational characteristics and specific resource requirements, and which are of limited duration. This has enabled the decomposition of the overall control algorithm into a set of subalgorithms, called subcontrollers, which can operate simultaneously and asynchronously. Coordinate transformations of sensor feedback data and actuator set-points have enabled the further simplification of the subcontrollers and have reduced their conflicting resource requirements. The modules of the decomposed control system are implemented as parallel processes with disjoint memory space communicating only by I/O. The synchronization mechanisms for dynamic resource allocation among subcontrollers and other synchronization mechanisms are also discussed in this paper. Such a software organization is suitable for the general form of multiprocessing using computer networks with distributed storage.

Vuskovic, M. I.↗
NASA NTRS1981

ARTS BETA testing report

The advanced real time system (ARTS) was tested utilizing existing commercial system hardware and software which has been operating under advanced operating system (AOS) for several years in a multitasking, multiprocessing, and multiple computer environment. Experiences with ARTS in terms of compatibility with AOS, ease of transmission between AOS and ARTS, and functional areas of ARTS which were tested are discussed. Relative and absolute performance of ARTS versus AOS as measured in the system environment are also presented.

Mccune, M. C.↗
NASA NTRS1979

Integrated testing and verification system for research flight software design document

The NASA Langley Research Center is developing the MUST (Multipurpose User-oriented Software Technology) program to cut the cost of producing research flight software through a system of software support tools. The HAL/S language is the primary subject of the design. Boeing Computer Services Company (BCS) has designed an integrated verification and testing capability as part of MUST. Documentation, verification and test options are provided with special attention on real time, multiprocessing issues. The needs of the entire software production cycle have been considered, with effective management and reduced lifecycle costs as foremost goals. Capabilities have been included in the design for static detection of data flow anomalies involving communicating concurrent processes. Some types of ill formed process synchronization and deadlock also are detected statically.

Taylor, R. N.↗
NASA NTRS1981

Laser velocimeter stand-alone controller

A distributed microprocessor network has been developed to position a laser-based velocity measurement package. Designed primarily for use inside the Ames 40 x 80-foot Subsonic Wind Tunnel, the instrument assembly is remotely operated. The mechanical system is reconfigurable for other test environments which necessitates an adaptive control approach. Three stepper motor drives provide two-dimensional positioning of the sampling point over 200/sq m of the test section, with a 5-mm resolution. Real-time multiprocessing provides fast response, fault detection, and parametric data acquisition. Manual tests are run from a dedicated control panel and automated tests are accomplished via an I.E.E.E 488 interface. The design approach and the progress to date are discussed.

Brown, R.↗