1,380 research outputs found

    ROPES : an expert system for condition analysis of winder ropes

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    Includes bibliographical references.This project was commissioned in order to provide engineers with the necessary knowledge of steel wire winder ropes so that they may make accurate decisions as to when a rope is near the end of its useful life. For this purpose, a knowledge base was compiled from the experience of experts in the field in order to create an expert system to aid the engineer in his task. The EXSYS expert system shell was used to construct a rule-based program which would be run on a personal computer. The program derived in this thesis is named ROPES, and provides information as to the forms of damage that may be present in a rope and the effect of any defects on rope strength and rope life. Advice is given as to the procedures that should be followed when damage is detected as well as the conditions which would necessitate rope discard and the urgency with which the replacement should take place. The expert system program will provide engineers with the necessary expertise and experience to assess, more accurately than at present, the condition of a winder rope. This should lead to longer rope life and improved safety with the associated cost savings. Rope assessment will also be more uniform with changes to policy being able to be implemented quickly and on an ongoing basis as technology and experience improves. The program ROPES, although compiled from expert knowledge, still requires the further input of personal opinions and inferences to some extent. For this reason, the program cannot be assumed infallible and must be used as an aid only

    Remote terminal system evaluation

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    An Earth Resources Data Processing System was developed to evaluate the system for training, technology transfer, and data processing. In addition to the five sites included in this project two other sites were connected to the system under separate agreements. The experience of these two sites is discussed. The results of the remote terminal project are documented in seven reports: one from each of the five project sites, Purdue University, and an overview report summarizing the other six reports

    Design of a fault tolerant airborne digital computer. Volume 1: Architecture

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    This volume is concerned with the architecture of a fault tolerant digital computer for an advanced commercial aircraft. All of the computations of the aircraft, including those presently carried out by analogue techniques, are to be carried out in this digital computer. Among the important qualities of the computer are the following: (1) The capacity is to be matched to the aircraft environment. (2) The reliability is to be selectively matched to the criticality and deadline requirements of each of the computations. (3) The system is to be readily expandable. contractible, and (4) The design is to appropriate to post 1975 technology. Three candidate architectures are discussed and assessed in terms of the above qualities. Of the three candidates, a newly conceived architecture, Software Implemented Fault Tolerance (SIFT), provides the best match to the above qualities. In addition SIFT is particularly simple and believable. The other candidates, Bus Checker System (BUCS), also newly conceived in this project, and the Hopkins multiprocessor are potentially more efficient than SIFT in the use of redundancy, but otherwise are not as attractive

    NASA Tech Briefs, November 2007

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    Topics include: Wireless Measurement of Contact and Motion Between Contact Surfaces; Wireless Measurement of Rotation and Displacement Rate; Portable Microleak-Detection System; Free-to-Roll Testing of Airplane Models in Wind Tunnels; Cryogenic Shrouds for Testing Thermal-Insulation Panels; Optoelectronic System Measures Distances to Multiple Targets; Tachometers Derived From a Brushless DC Motor; Algorithm-Based Fault Tolerance for Numerical Subroutines; Computational Support for Technology- Investment Decisions; DSN Resource Scheduling; Distributed Operations Planning; Phase-Oriented Gear Systems; Freeze Tape Casting of Functionally Graded Porous Ceramics; Electrophoretic Deposition on Porous Non- Conductors; Two Devices for Removing Sludge From Bioreactor Wastewater; Portable Unit for Metabolic Analysis; Flash Diffusivity Technique Applied to Individual Fibers; System for Thermal Imaging of Hot Moving Objects; Large Solar-Rejection Filter; Improved Readout Scheme for SQUID-Based Thermometry; Error Rates and Channel Capacities in Multipulse PPM; Two Mathematical Models of Nonlinear Vibrations; Simpler Adaptive Selection of Golomb Power-of- Two Codes; VCO PLL Frequency Synthesizers for Spacecraft Transponders; Wide Tuning Capability for Spacecraft Transponders; Adaptive Deadband Synchronization for a Spacecraft Formation; Analysis of Performance of Stereoscopic-Vision Software; Estimating the Inertia Matrix of a Spacecraft; Spatial Coverage Planning for Exploration Robots; and Increasing the Life of a Xenon-Ion Spacecraft Thruster

    Army-NASA aircrew/aircraft integration program (A3I) software detailed design document, phase 3

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    The capabilities and design approach of the MIDAS (Man-machine Integration Design and Analysis System) computer-aided engineering (CAE) workstation under development by the Army-NASA Aircrew/Aircraft Integration Program is detailed. This workstation uses graphic, symbolic, and numeric prototyping tools and human performance models as part of an integrated design/analysis environment for crewstation human engineering. Developed incrementally, the requirements and design for Phase 3 (Dec. 1987 to Jun. 1989) are described. Software tools/models developed or significantly modified during this phase included: an interactive 3-D graphic cockpit design editor; multiple-perspective graphic views to observe simulation scenarios; symbolic methods to model the mission decomposition, equipment functions, pilot tasking and loading, as well as control the simulation; a 3-D dynamic anthropometric model; an intermachine communications package; and a training assessment component. These components were successfully used during Phase 3 to demonstrate the complex interactions and human engineering findings involved with a proposed cockpit communications design change in a simulated AH-64A Apache helicopter/mission that maps to empirical data from a similar study and AH-1 Cobra flight test

    An application of an ethernet based protocol for communication and control in automated manufacturing

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    The exchange of information in the industrial environment is essential in order to achieve complete integration and control of manufacturing processes. At present the majority of devices present in the shop floor environment are still used as stand alone machines. They do not take advantage of the possibilities offered by a communication link to improve the manufacturing process. The subject of this research has been centered on the development of a simple, flexible and inexpensive support system for communication and control of manufacturing processes. As a result, a system with these features has been proposed and implemented on a simulated workcell. The area footwear manufacturing was chosen for modelling the workcell. The components of the manufacturing support system were developed using an object oriented approach which allowed modularity and software reuse. In order to achieve communication between the components, a communication protocol was developed following the process defined in the rapid protocol implementation framework. Ethernet was selected for implementing the lower levels of the protocol. Java, a new object oriented programming language used for the implementation of the system, showed that it could became a promising language for the implementation of manufacturing applications. In particular the platform independence feature of the language allows the immediate porting of applications to systems with different features. The manufacturing cell simulation had shown that the times associated with the manufacturing support system operations are compatible for its use in applications where the response times are in the order of one second
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