Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369450
Hagbae Kim, K. Shin
Modeling fault behaviors such as fault occurrences and active/benign durations is an essential step to the design and evaluation of fault-tolerant controller computers. We use a beta-binomial distribution to model fault occurrences both in the presence and in the absence of environmentally-induced (thus common-cause) faults. A multinomial distribution is used to model fault active durations. The proposed model is validated by testing it against the data generated by a simulation program that mimics a common-cause fault environment. The model is then applied to the determination of an optimal time-redundancy recovery method for EMI-induced failures in an N-modular redundant controller computer, demonstrating its utility and power.<>
{"title":"Modeling of externally-induced/common-cause faults in fault-tolerant systems","authors":"Hagbae Kim, K. Shin","doi":"10.1109/DASC.1994.369450","DOIUrl":"https://doi.org/10.1109/DASC.1994.369450","url":null,"abstract":"Modeling fault behaviors such as fault occurrences and active/benign durations is an essential step to the design and evaluation of fault-tolerant controller computers. We use a beta-binomial distribution to model fault occurrences both in the presence and in the absence of environmentally-induced (thus common-cause) faults. A multinomial distribution is used to model fault active durations. The proposed model is validated by testing it against the data generated by a simulation program that mimics a common-cause fault environment. The model is then applied to the determination of an optimal time-redundancy recovery method for EMI-induced failures in an N-modular redundant controller computer, demonstrating its utility and power.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132114649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369459
D. Ballard, L. Rippy
This paper describes a multi-year research and development effort to develop a system for performing situation assessment in next-generation Army helicopters. We first provide a formal definition of situation assessment and describe the motivation for the architecture based on studies in human cognition and attention. The paper describes the overall architecture and the processing paradigm used in performing situation assessment. In particular, we show how extensive knowledge about the battlefield, the threat, terrain, enemy and friendly doctrine can be used to aid in performing situation assessment. We also show how the overall inferencing process can be controlled in such a way as to bound the requirements for scarce computational resources. We describe a system composed of three independent reasoning subsystems performing recognition, evaluation and prediction. We also describe the knowledge bases and important data structures used in developing the system.<>
{"title":"A knowledge-based decision aid for enhanced situational awareness","authors":"D. Ballard, L. Rippy","doi":"10.1109/DASC.1994.369459","DOIUrl":"https://doi.org/10.1109/DASC.1994.369459","url":null,"abstract":"This paper describes a multi-year research and development effort to develop a system for performing situation assessment in next-generation Army helicopters. We first provide a formal definition of situation assessment and describe the motivation for the architecture based on studies in human cognition and attention. The paper describes the overall architecture and the processing paradigm used in performing situation assessment. In particular, we show how extensive knowledge about the battlefield, the threat, terrain, enemy and friendly doctrine can be used to aid in performing situation assessment. We also show how the overall inferencing process can be controlled in such a way as to bound the requirements for scarce computational resources. We describe a system composed of three independent reasoning subsystems performing recognition, evaluation and prediction. We also describe the knowledge bases and important data structures used in developing the system.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"30 17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134601980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369410
R. Hicks, W. Halstead
The liquid crystal display (LCD) is rapidly becoming the technology of choice for high brightness, sunlight readable displays. One of the major drawbacks to this technology is the need for a high luminosity backlight. Fluorescent tubes, one of the most efficient methods of converting electrical energy into light, poorly fit the mechanical and optical requirements of LCD's. Many attempts have been made to address these issues by developing a light source that better meets the optical and mechanical requirements of LCD's. The wafer light is a flat lamp developed specifically to meet the peculiar requirements of avionic displays, and has demonstrated significantly improved efficiency, uniformity, and thermal characteristics.<>
{"title":"Flat fluorescent lamp technology for LCD's","authors":"R. Hicks, W. Halstead","doi":"10.1109/DASC.1994.369410","DOIUrl":"https://doi.org/10.1109/DASC.1994.369410","url":null,"abstract":"The liquid crystal display (LCD) is rapidly becoming the technology of choice for high brightness, sunlight readable displays. One of the major drawbacks to this technology is the need for a high luminosity backlight. Fluorescent tubes, one of the most efficient methods of converting electrical energy into light, poorly fit the mechanical and optical requirements of LCD's. Many attempts have been made to address these issues by developing a light source that better meets the optical and mechanical requirements of LCD's. The wafer light is a flat lamp developed specifically to meet the peculiar requirements of avionic displays, and has demonstrated significantly improved efficiency, uniformity, and thermal characteristics.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133609365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369455
J. Yelverton
Parallel error-correction permits maximum throughput to be obtained from state-of-the-art RISC and CISC pipelined microprocessors used in high-performance digital avionics applications. As clock rates grow for commercially-based technology, it becomes increasingly prohibitive to permit memory bandwidth to be restricted by traditional in-line error correction methods. An alternative architecture is presented utilizing off-line error detection and correction, that clears errors essentially "after-the-fact" (or as needed); allowing a direct flow path from memory to central processor unit.<>
{"title":"Parallel error-correction architecture","authors":"J. Yelverton","doi":"10.1109/DASC.1994.369455","DOIUrl":"https://doi.org/10.1109/DASC.1994.369455","url":null,"abstract":"Parallel error-correction permits maximum throughput to be obtained from state-of-the-art RISC and CISC pipelined microprocessors used in high-performance digital avionics applications. As clock rates grow for commercially-based technology, it becomes increasingly prohibitive to permit memory bandwidth to be restricted by traditional in-line error correction methods. An alternative architecture is presented utilizing off-line error detection and correction, that clears errors essentially \"after-the-fact\" (or as needed); allowing a direct flow path from memory to central processor unit.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130538786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369460
D. A. Grave
Existing aircraft instrument panels are capable of supplying only limited data to pilots. Adding information such as forward looking infrared radar or digital map is limited by the display media currently in the cockpit. Electromechanical instruments such as horizontal situation indicators (HSI) and attitude direction indicators (ADI) are dedicated instruments which are becoming increasingly expensive to maintain as they come to the end of their product life cycle. They contain many moving parts and weigh several pounds each. The large panel depth required also limits the locations where electromechanical instruments and CRTs can be used. Several new core products and technologies have been developed which utilize active matrix liquid crystal displays (AMLCD) to provide pilots in military and commercial applications vital information. This paper describes the key characteristics of the displays, including operation in day and night mode operation and performance in military environments.<>
{"title":"Upgrading electromechanical instruments and CRT displays with active matrix liquid crystal displays","authors":"D. A. Grave","doi":"10.1109/DASC.1994.369460","DOIUrl":"https://doi.org/10.1109/DASC.1994.369460","url":null,"abstract":"Existing aircraft instrument panels are capable of supplying only limited data to pilots. Adding information such as forward looking infrared radar or digital map is limited by the display media currently in the cockpit. Electromechanical instruments such as horizontal situation indicators (HSI) and attitude direction indicators (ADI) are dedicated instruments which are becoming increasingly expensive to maintain as they come to the end of their product life cycle. They contain many moving parts and weigh several pounds each. The large panel depth required also limits the locations where electromechanical instruments and CRTs can be used. Several new core products and technologies have been developed which utilize active matrix liquid crystal displays (AMLCD) to provide pilots in military and commercial applications vital information. This paper describes the key characteristics of the displays, including operation in day and night mode operation and performance in military environments.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125002844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369494
S. Vestal
Specialized application generation tools are increasingly being used to automatically produce software in various application domains such as guidance, navigation and control. Many different tools may be used together to generate or assemble different parts of the same application. We discuss a toolset we have been developing to automatically generate GN&C and embedded software and the approach we are pursuing to assure the correctness of the generated applications.<>
{"title":"Assuring the correctness of automatically generated software","authors":"S. Vestal","doi":"10.1109/DASC.1994.369494","DOIUrl":"https://doi.org/10.1109/DASC.1994.369494","url":null,"abstract":"Specialized application generation tools are increasingly being used to automatically produce software in various application domains such as guidance, navigation and control. Many different tools may be used together to generate or assemble different parts of the same application. We discuss a toolset we have been developing to automatically generate GN&C and embedded software and the approach we are pursuing to assure the correctness of the generated applications.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125223864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369480
R. Strain, G.W. Flathers
In this paper, the functional architecture of the airborne positioning and planning system (APAPS) is presented at an introductory level. This system is comprised of a set of basic navigation and communication functions which are organized in such a way as to (1) assist the pilot in positioning and moving his aircraft through the airspace in pursuit of the goals that he has established for the flight, and (2) provide the basis to coordinate such movement with other aircraft in the context of a revised philosophy of air traffic management. The functional architecture presented here is the result of a holistic design approach which jointly considers the needs of the pilot and the air traffic system, and makes possible a whole new array of innovative, cost-effective, and convenient methods for coordinating aircraft movement. It was also designed with the full spectrum of airspace users in mind to ensure that benefits from improved safety, flexibility, and airspace access and utilization are realized by all segments of the user community.<>
{"title":"The airborne positioning and planning system: an architecture for future avionics systems design","authors":"R. Strain, G.W. Flathers","doi":"10.1109/DASC.1994.369480","DOIUrl":"https://doi.org/10.1109/DASC.1994.369480","url":null,"abstract":"In this paper, the functional architecture of the airborne positioning and planning system (APAPS) is presented at an introductory level. This system is comprised of a set of basic navigation and communication functions which are organized in such a way as to (1) assist the pilot in positioning and moving his aircraft through the airspace in pursuit of the goals that he has established for the flight, and (2) provide the basis to coordinate such movement with other aircraft in the context of a revised philosophy of air traffic management. The functional architecture presented here is the result of a holistic design approach which jointly considers the needs of the pilot and the air traffic system, and makes possible a whole new array of innovative, cost-effective, and convenient methods for coordinating aircraft movement. It was also designed with the full spectrum of airspace users in mind to ensure that benefits from improved safety, flexibility, and airspace access and utilization are realized by all segments of the user community.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129142214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369435
J. Nilsson
The Swedish Civil Aviation Administration (SCAA) has arrived at the conclusion that the most promising technology to meet some of the fundamental requirements of GNSS-based CNS/ATM applications is the introduction of the GNSS transponder and its GNSS-time synchronized self-organising Time Division Multiple Access (TDMA) data link which is a Two Way Data Link (TWDL). The GNSS Transponder includes a high precision GNSS receivers, communication processors and transceivers which can be integrated with other ATC and aircraft systems. This article discusses some of the available alternatives. The principal SCAA concerns with the Carrier Sense Multiple Access (CSMA) VHF data link (VDL) concept studied by the TCAO Aeronautical Mobile Communications Panel (AMCP) are related to its inability to meet requirements for time-critical message transfer. Without the capability to meet such requirements, the CSMA VHF Data Link (VDL) will have to be supplemented with another data link concept. The most promising alternative is the VDL concept which could form the basis for a single VDL concept for all phases of flight with the capability to satisfy all user needs. This VDL is based on GNSS-time synchronized self-organising Time Division Multiple Access (TDMA) technology with very precisely defined timeslots. During the evaluation-programme 2,250 time-slots for complete airborne ADS reports within the 1 minute frame have been used.<>
{"title":"The GNSS transponder and the time synchronized self organizing TDMA data link-a key to the implementation of cost-effective GNSS-based CNS/ATM systems","authors":"J. Nilsson","doi":"10.1109/DASC.1994.369435","DOIUrl":"https://doi.org/10.1109/DASC.1994.369435","url":null,"abstract":"The Swedish Civil Aviation Administration (SCAA) has arrived at the conclusion that the most promising technology to meet some of the fundamental requirements of GNSS-based CNS/ATM applications is the introduction of the GNSS transponder and its GNSS-time synchronized self-organising Time Division Multiple Access (TDMA) data link which is a Two Way Data Link (TWDL). The GNSS Transponder includes a high precision GNSS receivers, communication processors and transceivers which can be integrated with other ATC and aircraft systems. This article discusses some of the available alternatives. The principal SCAA concerns with the Carrier Sense Multiple Access (CSMA) VHF data link (VDL) concept studied by the TCAO Aeronautical Mobile Communications Panel (AMCP) are related to its inability to meet requirements for time-critical message transfer. Without the capability to meet such requirements, the CSMA VHF Data Link (VDL) will have to be supplemented with another data link concept. The most promising alternative is the VDL concept which could form the basis for a single VDL concept for all phases of flight with the capability to satisfy all user needs. This VDL is based on GNSS-time synchronized self-organising Time Division Multiple Access (TDMA) technology with very precisely defined timeslots. During the evaluation-programme 2,250 time-slots for complete airborne ADS reports within the 1 minute frame have been used.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128450928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369510
E. Rydell
This paper explores and explains the parameters associated with the different classes of interconnection communications required for the application of modular architectures and concepts in an avionics environment. Some of these classes require virtual connectivity. Other classes require several levels of latency and levels of priority to support the requirements. The required connectivity acknowledgments and information receipt confirmation acknowledgments necessity to support all of these classes, are discussed in detail. The abstract defends the necessity of keeping to a generic backplane architecture which will support various protocols, but is aimed in particular at a serial, fiber optic interconnection. Discussion includes advantages of this approach which allows ease of bridging to other avionics module/system racks, and interfacing through a gateway to the aircraft bus.<>
{"title":"Avionics \"backbone\" interconnection for busing in the backplane: advantages of serial busing","authors":"E. Rydell","doi":"10.1109/DASC.1994.369510","DOIUrl":"https://doi.org/10.1109/DASC.1994.369510","url":null,"abstract":"This paper explores and explains the parameters associated with the different classes of interconnection communications required for the application of modular architectures and concepts in an avionics environment. Some of these classes require virtual connectivity. Other classes require several levels of latency and levels of priority to support the requirements. The required connectivity acknowledgments and information receipt confirmation acknowledgments necessity to support all of these classes, are discussed in detail. The abstract defends the necessity of keeping to a generic backplane architecture which will support various protocols, but is aimed in particular at a serial, fiber optic interconnection. Discussion includes advantages of this approach which allows ease of bridging to other avionics module/system racks, and interfacing through a gateway to the aircraft bus.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"366 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121728797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369481
J. Leung, M. Wei, M. Aoyagi
National Aeronautics and Space Administration, Ames Research Center, recently completed the joint NASA/Army UH-60A Airloads Program. The objective of this program was to make in-flight the measurements of rotor blade airloads, blade vortex interaction, and blade acoustics. An advanced digital instrumentation system, capable of synchronous acquisition of several hundred high frequency pressure channels was designed and developed to gather the required airloads data. The instrumentation system was designed to operate on the rotor hub of a Blackhawk helicopter acquiring data, in night, from pressure transducers, strain gauges, and accelerometers embedded in the rotor blade, built under contract by Sikorsky Aircraft. A parallel effort was initiated to develop a ground telemetry system with the capability to handle the 7.5 megabits per second PCM-encoded telemetry data, generated by the instrumentation system, in real-time. The purpose of this paper is to describe the design and performance of the rotary data acquisition system which was used to digitally acquire high speed rotor blade pressure data. These data were found to achieve the flight test research objectives of the UH-60A Airloads Program.<>
{"title":"UH-60A airloads data acquisition and processing system","authors":"J. Leung, M. Wei, M. Aoyagi","doi":"10.1109/DASC.1994.369481","DOIUrl":"https://doi.org/10.1109/DASC.1994.369481","url":null,"abstract":"National Aeronautics and Space Administration, Ames Research Center, recently completed the joint NASA/Army UH-60A Airloads Program. The objective of this program was to make in-flight the measurements of rotor blade airloads, blade vortex interaction, and blade acoustics. An advanced digital instrumentation system, capable of synchronous acquisition of several hundred high frequency pressure channels was designed and developed to gather the required airloads data. The instrumentation system was designed to operate on the rotor hub of a Blackhawk helicopter acquiring data, in night, from pressure transducers, strain gauges, and accelerometers embedded in the rotor blade, built under contract by Sikorsky Aircraft. A parallel effort was initiated to develop a ground telemetry system with the capability to handle the 7.5 megabits per second PCM-encoded telemetry data, generated by the instrumentation system, in real-time. The purpose of this paper is to describe the design and performance of the rotary data acquisition system which was used to digitally acquire high speed rotor blade pressure data. These data were found to achieve the flight test research objectives of the UH-60A Airloads Program.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115030013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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