Pub Date : 1995-11-05DOI: 10.1109/DASC.1995.482936
Andrew J. Poggio, R. Zacharias, S. Pennock, C. Avalle
The data acquisition phase of a program intended to provide data for the validation of computational, analytical and experimental for the assessment of electromagnetic effects i n transports, for the checkout of instrumentation for following test programs, and for the support of protection engineering of airborne systems has been completed. Funded by the NASA Fly-By-Light/Power-By-Wire Program, the initial phase involved on-the-ground electromagnetic measurements using the NASA Boeing 757 and was executed in the LESLI Facility at the USAF Phillips Laboratory. The major participants were LLNL, NASA Langley Research Center, Phillips Laboratory, and UIE, Inc. Measurements were made of the fields coupled into the aircraft interior and signals induced in select structures and equipment under controlled illumination by RF fields. A characterization of the ground was also performed to permit ground effects to be included in forthcoming validation exercises. A series of fly-by experiments were conducted in early 1995 in which the NASA B-757 was flown in the vicinity of a Voice of America station ({approximately}25 MHz), a fixed transmitter driving an LP array (172 MHz), and an ASRF radar at Wallops Island (430 MHz). In this paper, the overall test program is defined with particular attention to the on-the-ground portion. It is described in detail with presentation of the test rationale, test layout, and samples of the data. Samples of some inferences from the data that will be useful in protection engineering and EM effects mitigation will also be presented.
{"title":"THE NASA B-757 HIRF TEST SERIES - LOW POWER ON-THE-GROUND TESTS","authors":"Andrew J. Poggio, R. Zacharias, S. Pennock, C. Avalle","doi":"10.1109/DASC.1995.482936","DOIUrl":"https://doi.org/10.1109/DASC.1995.482936","url":null,"abstract":"The data acquisition phase of a program intended to provide data for the validation of computational, analytical and experimental for the assessment of electromagnetic effects i n transports, for the checkout of instrumentation for following test programs, and for the support of protection engineering of airborne systems has been completed. Funded by the NASA Fly-By-Light/Power-By-Wire Program, the initial phase involved on-the-ground electromagnetic measurements using the NASA Boeing 757 and was executed in the LESLI Facility at the USAF Phillips Laboratory. The major participants were LLNL, NASA Langley Research Center, Phillips Laboratory, and UIE, Inc. Measurements were made of the fields coupled into the aircraft interior and signals induced in select structures and equipment under controlled illumination by RF fields. A characterization of the ground was also performed to permit ground effects to be included in forthcoming validation exercises. A series of fly-by experiments were conducted in early 1995 in which the NASA B-757 was flown in the vicinity of a Voice of America station ({approximately}25 MHz), a fixed transmitter driving an LP array (172 MHz), and an ASRF radar at Wallops Island (430 MHz). In this paper, the overall test program is defined with particular attention to the on-the-ground portion. It is described in detail with presentation of the test rationale, test layout, and samples of the data. Samples of some inferences from the data that will be useful in protection engineering and EM effects mitigation will also be presented.","PeriodicalId":125963,"journal":{"name":"Proceedings of 14th Digital Avionics Systems Conference","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127061992","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 : 1995-11-05DOI: 10.1109/DASC.1995.482923
T. Bridges, S. Johnston, M. Moore
This paper describes a methodology referred to as "channelization" used to ensure a system design meets failure tolerance requirements with a given set of components. In general, channelization is the assignment of one or more failure tolerant system functions to the proper utility resources. This paper provides an expanded view of the methodology by focusing on channelization of functions and their relationships as they relate to mission and operational objectives. A discussion of the benefits derived from channelization is provided along with a discussion of a simple tool used in validating the design. The material conveys experience gained by the Integrated Systems Architecture team that is part of the International Space Station (ISS) program. Examples from ISS are used throughout.
{"title":"Methodologies for enhancing operability of failure tolerant systems [in International Space Station]","authors":"T. Bridges, S. Johnston, M. Moore","doi":"10.1109/DASC.1995.482923","DOIUrl":"https://doi.org/10.1109/DASC.1995.482923","url":null,"abstract":"This paper describes a methodology referred to as \"channelization\" used to ensure a system design meets failure tolerance requirements with a given set of components. In general, channelization is the assignment of one or more failure tolerant system functions to the proper utility resources. This paper provides an expanded view of the methodology by focusing on channelization of functions and their relationships as they relate to mission and operational objectives. A discussion of the benefits derived from channelization is provided along with a discussion of a simple tool used in validating the design. The material conveys experience gained by the Integrated Systems Architecture team that is part of the International Space Station (ISS) program. Examples from ISS are used throughout.","PeriodicalId":125963,"journal":{"name":"Proceedings of 14th Digital Avionics Systems Conference","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127529500","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 : 1995-11-05DOI: 10.1109/DASC.1995.482802
W. Turner
This paper describes the use of the ITU-T specification and description language (SDL) formal description technique to specify the AVPAC avionics protocol, and use of the code-generating abilities of SDL tools to generate source code for an FDAC experiment to provide air-ground radio communications for low-visibility taxi tests at the FAA Technical Center.
{"title":"Use of formal description techniques in development and implementation of AVPAC protocol","authors":"W. Turner","doi":"10.1109/DASC.1995.482802","DOIUrl":"https://doi.org/10.1109/DASC.1995.482802","url":null,"abstract":"This paper describes the use of the ITU-T specification and description language (SDL) formal description technique to specify the AVPAC avionics protocol, and use of the code-generating abilities of SDL tools to generate source code for an FDAC experiment to provide air-ground radio communications for low-visibility taxi tests at the FAA Technical Center.","PeriodicalId":125963,"journal":{"name":"Proceedings of 14th Digital Avionics Systems Conference","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114461147","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 : 1995-11-05DOI: 10.1109/DASC.1995.482801
A. Pritchett, A. Midkiff, R. Hansman
As part of the Federal Aviation Administration's National Airspace System modernization plan, digital datalink communications will be introduced as a means of air/ground information exchange. Care must be taken, however, to continue to provide pilots with the 'Party Line' Information (PLI) that pilots currently overhear on the shared voice frequencies. Several studies have examined the importance of PLI through surveys and simulator studies. Pilots have consistently rated PLI as 'Important', with several specific information elements identified as 'Critical'. However, PLI is not a reliable source of information during high workload conditions, and it is not always compelling enough for pilots to commit to a required action for safety. Therefore, several recommendations can be made for datalink communications.
{"title":"'Party line' information use studies and implications for ATC datalink communications","authors":"A. Pritchett, A. Midkiff, R. Hansman","doi":"10.1109/DASC.1995.482801","DOIUrl":"https://doi.org/10.1109/DASC.1995.482801","url":null,"abstract":"As part of the Federal Aviation Administration's National Airspace System modernization plan, digital datalink communications will be introduced as a means of air/ground information exchange. Care must be taken, however, to continue to provide pilots with the 'Party Line' Information (PLI) that pilots currently overhear on the shared voice frequencies. Several studies have examined the importance of PLI through surveys and simulator studies. Pilots have consistently rated PLI as 'Important', with several specific information elements identified as 'Critical'. However, PLI is not a reliable source of information during high workload conditions, and it is not always compelling enough for pilots to commit to a required action for safety. Therefore, several recommendations can be made for datalink communications.","PeriodicalId":125963,"journal":{"name":"Proceedings of 14th Digital Avionics Systems Conference","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123180988","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 : 1995-11-05DOI: 10.1109/DASC.1995.482921
D. Eyles
The International Space Station will be the most complex and expensive spacecraft ever to fly. Making best use of this costly resource requires tools to assist the planning of operations, and to automate the execution of operational procedures. These capabilities, which operate in close association with each other, are known as "plans and procedures". The "plans" system maintains and executes the "onboard short term plan", an integrated schedule that includes all space station manual and automated activities. This software supports a graphic display presenting the plan to the crew; allows the ground and onboard crew to add, delete and edit activities; tracks the status of each activity; and automatically initiates automated procedures. The "procedures" capability involves procedure executors installed in various space station computers. This software provides the ability to create on the ground, and execute onboard, automated procedures to supplement the human role in operating the spacecraft and its payloads.
{"title":"Plans and procedures on the International Space Station","authors":"D. Eyles","doi":"10.1109/DASC.1995.482921","DOIUrl":"https://doi.org/10.1109/DASC.1995.482921","url":null,"abstract":"The International Space Station will be the most complex and expensive spacecraft ever to fly. Making best use of this costly resource requires tools to assist the planning of operations, and to automate the execution of operational procedures. These capabilities, which operate in close association with each other, are known as \"plans and procedures\". The \"plans\" system maintains and executes the \"onboard short term plan\", an integrated schedule that includes all space station manual and automated activities. This software supports a graphic display presenting the plan to the crew; allows the ground and onboard crew to add, delete and edit activities; tracks the status of each activity; and automatically initiates automated procedures. The \"procedures\" capability involves procedure executors installed in various space station computers. This software provides the ability to create on the ground, and execute onboard, automated procedures to supplement the human role in operating the spacecraft and its payloads.","PeriodicalId":125963,"journal":{"name":"Proceedings of 14th Digital Avionics Systems Conference","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126319944","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 : 1995-11-05DOI: 10.1109/DASC.1995.482814
S. Vakil, R. Hansman, A. Midkiff
An examination of autoflight systems in modern aircraft was made, with emphasis on the complex mode structure which is suspect in several recent accidents. Aviation Safety Reporting System reports and Flight Mode Annunciator conventions were examined. Principal results identified the lack of a consistent global model of the Autoflight System architecture and identified the vertical channel as requiring enhanced feedback. Functional requirements for an electronic vertical situation display (EVSD) were created based on established conventions and identified mode awareness problems. A preliminary version of this display was prototyped and an evaluation methodology was proposed. A set of experimental scenarios based on various types of mode awareness problems was established and discussed.
{"title":"Impact of vertical situation information on vertical mode awareness in advanced autoflight systems","authors":"S. Vakil, R. Hansman, A. Midkiff","doi":"10.1109/DASC.1995.482814","DOIUrl":"https://doi.org/10.1109/DASC.1995.482814","url":null,"abstract":"An examination of autoflight systems in modern aircraft was made, with emphasis on the complex mode structure which is suspect in several recent accidents. Aviation Safety Reporting System reports and Flight Mode Annunciator conventions were examined. Principal results identified the lack of a consistent global model of the Autoflight System architecture and identified the vertical channel as requiring enhanced feedback. Functional requirements for an electronic vertical situation display (EVSD) were created based on established conventions and identified mode awareness problems. A preliminary version of this display was prototyped and an evaluation methodology was proposed. A set of experimental scenarios based on various types of mode awareness problems was established and discussed.","PeriodicalId":125963,"journal":{"name":"Proceedings of 14th Digital Avionics Systems Conference","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132522111","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 : 1995-11-05DOI: 10.1109/DASC.1995.482805
R. Kerr
The integrated avionics architecture of the Boeing 777 airplane, where several functions normally housed in separate computer units are implemented within a single avionics cabinet, presented some unique opportunities and challenges for the implementation of the data link functionality. The Data Communications Management Function (DCMF) is responsible for the communications routing protocols, both for the ACARS air-ground communications and the onboard, fiber optic avionics network. The Flight Deck Communications Function (FDCF) implements the crew interface to the data Link function using a Cursor Control Device (CCD) and Multi-Function Display (MFD) in addition to the conventional Control and Display Unit (CDU) and printer. FDCF is also responsible for the implementation of the customer unique Aeronautical Operational Control (AOC) applications which may be tailor-made and loaded into the system by the airline customer using a ground-based tool. This paper discusses the architectural and operational characteristics of the data link function on the Boeing 777 airplane, and consider how future data link applications and protocols may be accommodated.
{"title":"Data communications management for the Boeing 777 airplane","authors":"R. Kerr","doi":"10.1109/DASC.1995.482805","DOIUrl":"https://doi.org/10.1109/DASC.1995.482805","url":null,"abstract":"The integrated avionics architecture of the Boeing 777 airplane, where several functions normally housed in separate computer units are implemented within a single avionics cabinet, presented some unique opportunities and challenges for the implementation of the data link functionality. The Data Communications Management Function (DCMF) is responsible for the communications routing protocols, both for the ACARS air-ground communications and the onboard, fiber optic avionics network. The Flight Deck Communications Function (FDCF) implements the crew interface to the data Link function using a Cursor Control Device (CCD) and Multi-Function Display (MFD) in addition to the conventional Control and Display Unit (CDU) and printer. FDCF is also responsible for the implementation of the customer unique Aeronautical Operational Control (AOC) applications which may be tailor-made and loaded into the system by the airline customer using a ground-based tool. This paper discusses the architectural and operational characteristics of the data link function on the Boeing 777 airplane, and consider how future data link applications and protocols may be accommodated.","PeriodicalId":125963,"journal":{"name":"Proceedings of 14th Digital Avionics Systems Conference","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121591516","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 : 1995-11-05DOI: 10.1109/DASC.1995.482807
H. Pilley, L. V. Pilley
The successful implementation of a seamless, DGPS-based airport navigation, control and management system is dependent on the successful integration of avionics and Air Traffic Management (ATM) technologies. Differential GPS (DGPS) position, velocity and time (PVT) data can provide pilots with world-wide, all-weather navigation capabilities, including forms of precision approach, taxi and departure guidance. Automatic Dependent Surveillance Broadcast (ADS-B) can give all participants a dynamic view of the airspace (or airport surface) and provide the ATM system with the inputs it needs to manage air and ground traffic safely and efficiently. Using common, safety-enhancing algorithms, GPS and datalink can provide improved benefits to the vast majority of aviation system users and operators. To maximize the strength and versatility of an integrated GPS-based airport system, international standards are required for navigation, geodesy, avionics, and datalink(s). The first step in developing these standards is the definition of high-level operational requirements for seamless airport operations. This paper describes a set of key, high-level operational requirements for a DGPS-based airport navigation, control and management system. The requirements are translated into a specific technology implementation utilizing GPS and datalink. The concepts presented here are based on the real time test activities conducted by DSDC at the Manchester, NH airport.
{"title":"Satisfying airport operational requirements using GNSS","authors":"H. Pilley, L. V. Pilley","doi":"10.1109/DASC.1995.482807","DOIUrl":"https://doi.org/10.1109/DASC.1995.482807","url":null,"abstract":"The successful implementation of a seamless, DGPS-based airport navigation, control and management system is dependent on the successful integration of avionics and Air Traffic Management (ATM) technologies. Differential GPS (DGPS) position, velocity and time (PVT) data can provide pilots with world-wide, all-weather navigation capabilities, including forms of precision approach, taxi and departure guidance. Automatic Dependent Surveillance Broadcast (ADS-B) can give all participants a dynamic view of the airspace (or airport surface) and provide the ATM system with the inputs it needs to manage air and ground traffic safely and efficiently. Using common, safety-enhancing algorithms, GPS and datalink can provide improved benefits to the vast majority of aviation system users and operators. To maximize the strength and versatility of an integrated GPS-based airport system, international standards are required for navigation, geodesy, avionics, and datalink(s). The first step in developing these standards is the definition of high-level operational requirements for seamless airport operations. This paper describes a set of key, high-level operational requirements for a DGPS-based airport navigation, control and management system. The requirements are translated into a specific technology implementation utilizing GPS and datalink. The concepts presented here are based on the real time test activities conducted by DSDC at the Manchester, NH airport.","PeriodicalId":125963,"journal":{"name":"Proceedings of 14th Digital Avionics Systems Conference","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122023457","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 : 1995-11-05DOI: 10.1109/DASC.1995.482912
Douglas L. Miller, G. Wolfman, A. J. Volanth
Systems engineering organizations are increasingly concerned with finding ways to be more “customer driven” and to establish “user-centered’ systems engineering practices. However, it is much easier to find recommendations than it is to find examples of successhl user-centered systems engineering. This paper reports the success of one organization in developing user-centered systems engineering practices through four hndamental organizational changes. First, a User Interface (UI) systems engineering team was established with responsibility for systems engineering activities critical to product usability; These activities included development of concepts of use, U1 prototypes, U1 requirements, and managing end-user program involvement. Second, the U1 design was incorporated into the software requirements specifications. Third, effective U1 processes were established for defining requirements, designing and evaluating the UI, and leveraging end-user expertise. Finally, commitment of management and engineering leadership brought about these organizational changes and made their success possible. INTRODUCTION Terms such as “customer driven,” “usercentered design,” and “user-centered systems engineering” can be found echoing through the halls of many systems development organizations today. They reflect a frequently perceived need to find ways to enhance the focus of the systems engineering process and organization on satis@ing customer needs. Customer needs take many forms, but in this case the concern typically has to do with providing systems that do an excellent job of supporting operators in performing their tasks (i.e., system usability); producing these systems within aggressive schedules and tight budgets; and, “getting it right the first time,” rather than through endless expensive system modifications after the system is built. A number of factors bear some responsibility for the growing focus on system usability. One factor is continued “system creep” as computer systems gradually get applied to more workplace tasks. Another related factor is the ever increasing use of computer systems in environments where the operators are experts at their jobs, not experts with computers. Of course, this focus is also partly the effect of past systems that did not adequately meet customer needs.
{"title":"USER-CENTERED SYSTEMS ENGINEERING: A SUCCESS STORY","authors":"Douglas L. Miller, G. Wolfman, A. J. Volanth","doi":"10.1109/DASC.1995.482912","DOIUrl":"https://doi.org/10.1109/DASC.1995.482912","url":null,"abstract":"Systems engineering organizations are increasingly concerned with finding ways to be more “customer driven” and to establish “user-centered’ systems engineering practices. However, it is much easier to find recommendations than it is to find examples of successhl user-centered systems engineering. This paper reports the success of one organization in developing user-centered systems engineering practices through four hndamental organizational changes. First, a User Interface (UI) systems engineering team was established with responsibility for systems engineering activities critical to product usability; These activities included development of concepts of use, U1 prototypes, U1 requirements, and managing end-user program involvement. Second, the U1 design was incorporated into the software requirements specifications. Third, effective U1 processes were established for defining requirements, designing and evaluating the UI, and leveraging end-user expertise. Finally, commitment of management and engineering leadership brought about these organizational changes and made their success possible. INTRODUCTION Terms such as “customer driven,” “usercentered design,” and “user-centered systems engineering” can be found echoing through the halls of many systems development organizations today. They reflect a frequently perceived need to find ways to enhance the focus of the systems engineering process and organization on satis@ing customer needs. Customer needs take many forms, but in this case the concern typically has to do with providing systems that do an excellent job of supporting operators in performing their tasks (i.e., system usability); producing these systems within aggressive schedules and tight budgets; and, “getting it right the first time,” rather than through endless expensive system modifications after the system is built. A number of factors bear some responsibility for the growing focus on system usability. One factor is continued “system creep” as computer systems gradually get applied to more workplace tasks. Another related factor is the ever increasing use of computer systems in environments where the operators are experts at their jobs, not experts with computers. Of course, this focus is also partly the effect of past systems that did not adequately meet customer needs.","PeriodicalId":125963,"journal":{"name":"Proceedings of 14th Digital Avionics Systems Conference","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121372046","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 : 1995-11-05DOI: 10.1109/DASC.1995.482915
J. Preston, Paul A. Little, L. Martin
The ability to accurately predict usable processing reserve is needed in many real-time software applications. Earlier research has shown that there are limits on the amount of available processor throughput that can be used to perform work with hard real-time deadlines. In this paper, we present an approach for determining and manipulating usable real-time processing reserve for multitasking systems that use preemptive, priority-based scheduling rules. Such systems must be prioritized using either rate monotonic, or deadline monotonic criteria. The approach computes real-time processing reserve for a schedulable task set, assuming that additional computation requirements will be levied on existing tasks. The approach includes a method for computing the maximum work that can be performed by an added task while preserving schedulability of the task set. Additionally, we introduce a method for balancing work within a task set to increase available real-time processing reserve. The method can be conditionally applied to harmonic tasks within a task set to improve the work efficiency of a processing resource.
{"title":"DETERMINING REAL-TIME PROCESSING RESERVE IN MULTITASKING SYSTEMS","authors":"J. Preston, Paul A. Little, L. Martin","doi":"10.1109/DASC.1995.482915","DOIUrl":"https://doi.org/10.1109/DASC.1995.482915","url":null,"abstract":"The ability to accurately predict usable processing reserve is needed in many real-time software applications. Earlier research has shown that there are limits on the amount of available processor throughput that can be used to perform work with hard real-time deadlines. In this paper, we present an approach for determining and manipulating usable real-time processing reserve for multitasking systems that use preemptive, priority-based scheduling rules. Such systems must be prioritized using either rate monotonic, or deadline monotonic criteria. The approach computes real-time processing reserve for a schedulable task set, assuming that additional computation requirements will be levied on existing tasks. The approach includes a method for computing the maximum work that can be performed by an added task while preserving schedulability of the task set. Additionally, we introduce a method for balancing work within a task set to increase available real-time processing reserve. The method can be conditionally applied to harmonic tasks within a task set to improve the work efficiency of a processing resource.","PeriodicalId":125963,"journal":{"name":"Proceedings of 14th Digital Avionics Systems Conference","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117183400","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：