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  • 1
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    Automated anomaly detection for Orbiter High Temperature Reusable Surface Insulation (1992)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: The description, analysis, and experimental results of a method for identifying possible defects on High Temperature Reusable Surface Insulation (HRSI) of the Orbiter Thermal Protection System (TPS) is presented. Currently, a visual postflight inspection of Orbiter TPS is conducted to detect and classify defects as part of the Orbiter maintenance flow. The objective of the method is to automate the detection of defects by identifying anomalies between preflight and postflight images of TPS components. The initial version is intended to detect and label gross (greater than 0.1 inches in the smallest dimension) anomalies on HRSI components for subsequent classification by a human inspector. The approach is a modified Golden Template technique where the preflight image of a tile serves as the template against which the postflight image of the tile is compared. Candidate anomalies are selected as a result of the comparison and processed to identify true anomalies. The processing methods are developed and discussed, and the results of testing on actual and simulated tile images are presented. Solutions to the problems of brightness and spatial normalization, timely execution, and minimization of false positives are also discussed.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: In: Cooperative intelligent robotics in space III; Proceedings of the Meeting, Boston, MA, Nov. 16-18, 1992 (A93-29101 10-54); p. 330-340.
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  • 2
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    Proportional proximity sensing for telerobots using Coherent Laser Radar (1992)
    In:  Other Sources
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    Publication Date: 2011-08-24
    Description: The ability of a telerobotic manipulator to operate in confined spaces while avoiding unwanted collisions is enhanced by the accurate sensing of its proximate environment. To achieve the fidelity required for precise manipulator control, a proportional proximity sensor system with a sufficiently large measurement envelope is required. Current proximity sensors provide a binary indication of the presence of obstacles within a small envelope with coarse or no proportional measurement of their location. A proportional proximity sensor system configured as a Frequency Modulated Continuous Wave (FMCW) Coherent Laser Radar (CLR) using a semiconductor laser as the energy source is described and analyzed. The source and reflected energies mix coherently to generate a radio frequency (RF) signal whose frequency is proportional to the range. The system is tested for accuracy, range, depth of range, speed, and sensitivity and the results are presented. Techniques to derive orientation information and an application to telerobotic control are also described.
    Keywords: LASERS AND MASERS
    Type: In: Cooperative intelligent robotics in space III; Proceedings of the Meeting, Boston, MA, Nov. 16-18, 1992 (A93-29101 10-54); p. 25-35.
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  • 3
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    Interactive Scene Analysis Module - A sensor-database fusion system for telerobotic environments (1992)
    In:  Other Sources
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    Publication Date: 2011-08-24
    Description: Accomplishing a task with telerobotics typically involves a combination of operator control/supervision and a 'script' of preprogrammed commands. These commands usually assume that the location of various objects in the task space conform to some internal representation (database) of that task space. The ability to quickly and accurately verify the task environment against the internal database would improve the robustness of these preprogrammed commands. In addition, the on-line initialization and maintenance of a task space database is difficult for operators using Cartesian coordinates alone. This paper describes the Interactive Scene' Analysis Module (ISAM) developed to provide taskspace database initialization and verification utilizing 3-D graphic overlay modelling, video imaging, and laser radar based range imaging. Through the fusion of taskspace database information and image sensor data, a verifiable taskspace model is generated providing location and orientation data for objects in a task space. This paper also describes applications of the ISAM in the Intelligent Systems Research Laboratory (ISRL) at NASA Langley Research Center, and discusses its performance relative to representation accuracy and operator interface efficiency.
    Keywords: MAN/SYSTEM TECHNOLOGY AND LIFE SUPPORT
    Type: In: Cooperative intelligent robotics in space II; Proceedings of the Meeting, Boston, MA, Nov. 12-14, 1991 (A93-27001 09-54); p. 334-345.
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  • 4
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    Monovision techniques for telerobots (1987)
    In:  Other Sources
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    Publication Date: 2018-12-01
    Description: The primary task of the vision sensor in a telerobotic system is to provide information about the position of the system's effector relative to objects of interest in its environment. The subtasks required to perform the primary task include image segmentation, object recognition, and object location and orientation in some coordinate system. The accomplishment of the vision task requires the appropriate processing tools and the system methodology to effectively apply the tools to the subtasks. This paper describes the functional structure of the telerobotic vision system used in the Langley Research Center's (LaRC) Intelligent Systems Research Laboratory (ISRL) and discusses two monovision techniques for accomplishing the vision subtasks.
    Keywords: MAN/SYSTEM TECHNOLOGY AND LIFE SUPPORT
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  • 5
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    The Aeronautical Data Link: Taxonomy, Architectural Analysis, and Optimization (2002)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: The future Communication, Navigation, and Surveillance/Air Traffic Management (CNS/ATM) System will rely on global satellite navigation, and ground-based and satellite based communications via Multi-Protocol Networks (e.g. combined Aeronautical Telecommunications Network (ATN)/Internet Protocol (IP)) to bring about needed improvements in efficiency and safety of operations to meet increasing levels of air traffic. This paper will discuss the development of an approach that completely describes optimal data link architecture configuration and behavior to meet the multiple conflicting objectives of concurrent and different operations functions. The practical application of the approach enables the design and assessment of configurations relative to airspace operations phases. The approach includes a formal taxonomic classification, an architectural analysis methodology, and optimization techniques. The formal taxonomic classification provides a multidimensional correlation of data link performance with data link service, information protocol, spectrum, and technology mode; and to flight operations phase and environment. The architectural analysis methodology assesses the impact of a specific architecture configuration and behavior on the local ATM system performance. Deterministic and stochastic optimization techniques maximize architectural design effectiveness while addressing operational, technology, and policy constraints.
    Keywords: Aircraft Communications and Navigation
    Type: 21st Digital Avionics Systems Conference; Oct 27, 2002 - Oct 31, 2002; Irvine, CA; United States
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  • 6
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    The Aeronautical Data Link: Decision Framework for Architecture Analysis (2003)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: A decision analytic approach that develops optimal data link architecture configuration and behavior to meet multiple conflicting objectives of concurrent and different airspace operations functions has previously been developed. The approach, premised on a formal taxonomic classification that correlates data link performance with operations requirements, information requirements, and implementing technologies, provides a coherent methodology for data link architectural analysis from top-down and bottom-up perspectives. This paper follows the previous research by providing more specific approaches for mapping and transitioning between the lower levels of the decision framework. The goal of the architectural analysis methodology is to assess the impact of specific architecture configurations and behaviors on the efficiency, capacity, and safety of operations. This necessarily involves understanding the various capabilities, system level performance issues and performance and interface concepts related to the conceptual purpose of the architecture and to the underlying data link technologies. Efficient and goal-directed data link architectural network configuration is conditioned on quantifying the risks and uncertainties associated with complex structural interface decisions. Deterministic and stochastic optimal design approaches will be discussed that maximize the effectiveness of architectural designs.
    Keywords: Aircraft Communications and Navigation
    Type: 3rd Integrated Commmunication, Navigation and Surveillance Conference; May 19, 2003 - May 22, 2003; Annapolis, MD; United States
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  • 7
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    Topographic Characterization (1993)
    In:  CASI
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    Publication Date: 2019-07-13
    Description: The National Aeronautics and Space Administration (NASA), other government agencies, and private industry have requirements to map and analyze 3-dimensional surfaces of varying regularity and material composition. This requires a high fidelity, 3-dimensional description of the work space. In cases where complete and current information about the space is not available, topographic characterization allows on-line initialization and/or modification of the work space database. The mapping environment is often challenging with regard to lighting, radiation, temperature, atmosphere, and causticity. This paper describes a system that provides topographic characterization based on fusing intensity and depth information, and describes the application of this technique for inspection of Shuttle thermal tiles.
    Keywords: Computer Programming and Software
    Type: Intelligent Information Systems, Sensor Fusion and Aerospace Applications; Apr 12, 1993 - Apr 16, 1993; Orlando, FL; United States
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  • 8
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    Location of planar targets in three space from monocular images (1987)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Many pieces of existing and proposed space hardware that would be targets of interest for a telerobot can be represented as planar or near-planar surfaces. Examples include the biostack modules on the Long Duration Exposure Facility, the panels on Solar Max, large diameter struts, and refueling receptacles. Robust and temporally efficient methods for locating such objects with sufficient accuracy are therefore worth developing. Two techniques that derive the orientation and location of an object from its monocular image are discussed and the results of experiments performed to determine translational and rotational accuracy are presented. Both the quadrangle projection and elastic matching techniques extract three-space information using a minimum of four identifiable target points and the principles of the perspective transformation. The selected points must describe a convex polygon whose geometric characteristics are prespecified in a data base. The rotational and translational accuracy of both techniques was tested at various ranges. This experiment is representative of the sensing requirements involved in a typical telerobot target acquisition task. Both techniques determined target location to an accuracy sufficient for consistent and efficient acquisition by the telerobot.
    Keywords: CYBERNETICS
    Type: NASA-TM-101868 , NAS 1.15:101868 , 1987 Conference on Space Applications of Artificial Intelligence (AI) and Robotics; May 13, 1987 - May 14, 1987; Greenbelt, MD; United States
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  • 9
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    Locating A Planar Target From An Image (1990)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: Report describes experiments to test two algorithms being considered for use in automatic control of robots and remote manipulators. One algorithm based on quadrangle-projection method, which involves use of four target points lying at corners of quadrangle. Other algorithm based on elastic-matching ("rubber-mask") approach, in which reference image warped to conform to actual image. Both algorithms determine position and orientation of target with accuracy sufficient for consistent and efficient acquisition by telerobot.
    Keywords: MATHEMATICS AND INFORMATION SCIENCES
    Type: LAR-14128 , NASA Tech Briefs (ISSN 0145-319X); 14; 12; P. 66
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  • 10
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    Analysis of Phase-Type Stochastic Petri Nets With Discrete and Continuous Timing (2000)
    In:  CASI
    Details
    Publication Date: 2019-07-10
    Description: The Petri net formalism is useful in studying many discrete-state, discrete-event systems exhibiting concurrency, synchronization, and other complex behavior. As a bipartite graph, the net can conveniently capture salient aspects of the system. As a mathematical tool, the net can specify an analyzable state space. Indeed, one can reason about certain qualitative properties (from state occupancies) and how they arise (the sequence of events leading there). By introducing deterministic or random delays, the model is forced to sojourn in states some amount of time, giving rise to an underlying stochastic process, one that can be specified in a compact way and capable of providing quantitative, probabilistic measures. We formalize a new non-Markovian extension to the Petri net that captures both discrete and continuous timing in the same model. The approach affords efficient, stationary analysis in most cases and efficient transient analysis under certain restrictions. Moreover, this new formalism has the added benefit in modeling fidelity stemming from the simultaneous capture of discrete- and continuous-time events (as opposed to capturing only one and approximating the other). We show how the underlying stochastic process, which is non-Markovian, can be resolved into simpler Markovian problems that enjoy efficient solutions. Solution algorithms are provided that can be easily programmed.
    Keywords: Numerical Analysis
    Type: NASA/CR-2000-210296 , NAS 1.16:210296
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