-
1
المؤلفون: Krier, G. E., Szalai, K. J., Megna, V. A., Brock, L. D., Jarvis, C. R., Odonnell, R. N.
المصدر: CASI
مصطلحات موضوعية: AIRCRAFT STABILITY AND CONTROL
جغرافية الموضوع: Unclassified, Unlimited, Publicly available
الوصف: The experience gained in digital fly-by-wire technology through a flight test program being conducted by the NASA Dryden Flight Research Center in an F-8C aircraft is described. The system requirements are outlined, along with the requirements for flight qualification. The system is described, including the hardware components, the aircraft installation, and the system operation. The flight qualification experience is emphasized. The qualification process included the theoretical validation of the basic design, laboratory testing of the hardware and software elements, systems level testing, and flight testing. The most productive testing was performed on an iron bird aircraft, which used the actual electronic and hydraulic hardware and a simulation of the F-8 characteristics to provide the flight environment. The iron bird was used for sensor and system redundancy management testing, failure modes and effects testing, and stress testing in many cases with the pilot in the loop. The flight test program confirmed the quality of the validation process by achieving 50 flights without a known undetected failure and with no false alarms.
وصف الملف: application/pdf
العلاقة: Document ID: 19790005938; Accession ID: 79N14109; http://hdl.handle.net/2060/19790005938Test
-
2
المؤلفون: Goodman, H. A., Brock, L. D.
المصدر: CASI
مصطلحات موضوعية: AIRCRAFT STABILITY AND CONTROL
جغرافية الموضوع: Unclassified, Unlimited, Publicly available
الوصف: The F-8 Digital Fly-by-Wire (DFBW) flight test program intended to provide the technology for advanced control systems, giving aircraft enhanced performance and operational capability is addressed. A detailed analysis of the experimental system was performed to estimated the probabilities of two significant safety critical events: (1) loss of primary flight control function, causing reversion to the analog bypass system; and (2) loss of the aircraft due to failure of the electronic flight control system. The analysis covers appraisal of risks due to random equipment failure, generic faults in design of the system or its software, and induced failure due to external events. A unique diagrammatic technique was developed which details the combinatorial reliability equations for the entire system, promotes understanding of system failure characteristics, and identifies the most likely failure modes. The technique provides a systematic method of applying basic probability equations and is augmented by a computer program written in a modular fashion that duplicates the structure of these equations.
وصف الملف: application/pdf
العلاقة: Document ID: 19820004206; Accession ID: 82N12079; http://hdl.handle.net/2060/19820004206Test
-
3
المؤلفون: Hopkins, A. L., Jansson, D. G., Smith, T. B., Brock, L. D., Martin, J. H., Serben, S., Hanley, L. D.
المصدر: CASI
مصطلحات موضوعية: COMMUNICATIONS AND RADAR
جغرافية الموضوع: Unclassified, Unlimited, Publicly available
الوصف: The application of communication structures to advanced transport aircraft are addressed. First, a set of avionic functional requirements is established, and a baseline set of avionics equipment is defined that will meet the requirements. Three alternative configurations for this equipment are then identified that represent the evolution toward more dispersed systems. Candidate communication structures are proposed for each system configuration, and these are compared using trade off analyses; these analyses emphasize reliability but also address complexity. Multiplex buses are recognized as the likely near term choice with mesh networks being desirable for advanced, highly dispersed systems.
وصف الملف: application/pdf
العلاقة: Document ID: 19820021635; Accession ID: 82N29511; http://hdl.handle.net/2060/19820021635Test
-
4
المؤلفون: Martin, J. H., Hanley, L. D., Hopkins, A. L., Jansson, D. G., Serben, S., Brock, L. D., Smith, T. B.
المصدر: CASI
مصطلحات موضوعية: COMMUNICATIONS AND RADAR
جغرافية الموضوع: Unclassified, Unlimited, Publicly available
الوصف: Candidate data communication techniques are identified, including dedicated links, local buses, broadcast buses, multiplex buses, and mesh networks. The design methodology for mesh networks is then discussed, including network topology and node architecture. Several concepts of power distribution are reviewed, including current limiting and mesh networks for power. The technology issues of packaging, transmission media, and lightning are addressed, and, finally, the analysis tools developed to aid in the communication design process are described. There are special tools to analyze the reliability and connectivity of networks and more general reliability analysis tools for all types of systems.
وصف الملف: application/pdf
العلاقة: Document ID: 19820021634; Accession ID: 82N29510; http://hdl.handle.net/2060/19820021634Test
-
5
المؤلفون: Brock, L. D., Lala, J.
المصدر: Other Sources
جغرافية الموضوع: Unclassified, Unlimited, Publicly available
الوقت: 62
الوصف: The Advanced Information Processing System (AIPS) is designed to provide a fault tolerant and damage tolerant data processing architecture for a broad range of aerospace vehicles. The AIPS architecture also has attributes to enhance system effectiveness such as graceful degradation, growth and change tolerance, integrability, etc. Two key building blocks being developed by the AIPS program are a fault and damage tolerant processor and communication network. A proof-of-concept system is now being built and will be tested to demonstrate the validity and performance of the AIPS concepts.
العلاقة: http://ntrs.nasa.gov/search.jsp?R=19870029489Test; Accession ID: 87A16763
-
6
المؤلفون: Brock, L. D., Goddman, H. A.
المصدر: Other Sources
جغرافية الموضوع: Unclassified, Unlimited, Publicly available
الوقت: 08
الوصف: An analysis technique has been developed to estimate the reliability of a very complex, safety-critical system by constructing a diagram of the reliability equations for the total system. This diagram has many of the characteristics of a fault-tree or success-path diagram, but is much easier to construct for complex redundant systems. The diagram provides insight into system failure characteristics and identifies the most likely failure modes. A computer program aids in the construction of the diagram and the computation of reliability. Analysis of the NASA F-8 Digital Fly-by-Wire Flight Control System is used to illustrate the technique.
العلاقة: http://ntrs.nasa.gov/search.jsp?R=19800061377Test; Accession ID: 80A45547
-
7
المؤلفون: Brock, L. D., Hopkins, A. L., Jr., Spencer, J. L.
المصدر: Other Sources
جغرافية الموضوع: Unclassified, Unlimited, Publicly available
الوقت: 04
الوصف: An investigation of active control communications sponsored by the NASA Langley Research Center is summarized. Particular attention is given to comparative architectures, for which a common set of requirements is generated as a baseline. Most of the requirements are aircraft functional in nature, such as stability and command augmentation, structural load relief, flight path control, flight control linkage, flight monitoring, management, navigation, engine control, and ground communication; the time element, the hazard environment, and the communications capacity estimation are also important factors. The architectures involve several communication technologies, including dedicated links, broadcast busing, and multiplex busing. The multiplex bus system provides the greatest flexibility and installation efficiency. A future homogeneous network system is also proposed, which would be fault and damage tolerant and would, with advanced technology, avoid the problems of designing a very large and flight critical multiplex bus system.
العلاقة: http://ntrs.nasa.gov/search.jsp?R=19820029985Test; Accession ID: 82A13520
-
8
المؤلفون: Brock, L. M.
المصدر: CASI
جغرافية الموضوع: Unclassified, Unlimited, Publicly available
الوقت: 39
الوصف: An idealized two-dimensional example of rapid interface flow extension is described. Initially undisturbed dissimilar isotropic, homogeneous, linearly elastic half-spaces are perfectly bonded along the interface y=0. Quantities associated with the half-space or = to 0 are denoted by the prime superscript or the subscripts 3 or 4 while those in y or = to 0 carry the subscripts 1 or 2. At time t=0 adjacent material points at x=0, y= + or - 0 are forced apart horizontally with a constant relative velocity delta v. This results in a zone of bond failure which extends symmetrically along the interface at a constant rate c. The newly created flaw surfaces are in sliding contact resisted by Coulomb friction. The friction coefficient is gamma.
العلاقة: http://ntrs.nasa.gov/search.jsp?R=19770003310Test; Accession ID: 77N10252
