Pub Date : 2009-03-07DOI: 10.1109/AERO.2009.4839434
D. Dibiase, J. Laramee
In 2011 NASA will launch the Mars Science Laboratory (MSL) as part of its Mars Exploration Program to learn more about the red planet's environment and geological history. To fulfill that goal, the MSL rover, built by NASA's Jet Propulsion Laboratory (JPL), is outfitted with the most extensive array of scientific instruments ever landed on the Martian surface. The Mars Hand Lens Imager (MAHLI), mounted on the end of the rover's robotic arm, is one of the primary science cameras for MSL. This camera affords many improvements over those used on previous Mars missions, particularly the ability to focus throughout a wide spatial range. A novel mechanism uses one motor to actuate an internal lens group, enabling focus capability, and manipulate a protective dust cover. This mechanism is designed to operate in the severe thermal environment of the MSL mission (−120° C to +40° C) and to survive for one Martian year with 3x margin (about 2000 Earth days) using non-standard materials and techniques in order to meet mass and optical requirements. Several issues involving lubrication and wear were encountered in developing this instrument; each solved through sound engineering and/or system level redesign. The qualification model passed full level life testing at temperatures throughout the operating range with negligible reduction in performance. Alliance Spacesystems, LLC supplied the flight model mechanism to Malin Space Science Systems (MSSS) where it was integrated with electronics and in turn delivered to JPL in October 2008.
{"title":"Mars hand lens imager: Lens mechanical design","authors":"D. Dibiase, J. Laramee","doi":"10.1109/AERO.2009.4839434","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839434","url":null,"abstract":"In 2011 NASA will launch the Mars Science Laboratory (MSL) as part of its Mars Exploration Program to learn more about the red planet's environment and geological history. To fulfill that goal, the MSL rover, built by NASA's Jet Propulsion Laboratory (JPL), is outfitted with the most extensive array of scientific instruments ever landed on the Martian surface. The Mars Hand Lens Imager (MAHLI), mounted on the end of the rover's robotic arm, is one of the primary science cameras for MSL. This camera affords many improvements over those used on previous Mars missions, particularly the ability to focus throughout a wide spatial range. A novel mechanism uses one motor to actuate an internal lens group, enabling focus capability, and manipulate a protective dust cover. This mechanism is designed to operate in the severe thermal environment of the MSL mission (−120° C to +40° C) and to survive for one Martian year with 3x margin (about 2000 Earth days) using non-standard materials and techniques in order to meet mass and optical requirements. Several issues involving lubrication and wear were encountered in developing this instrument; each solved through sound engineering and/or system level redesign. The qualification model passed full level life testing at temperatures throughout the operating range with negligible reduction in performance. Alliance Spacesystems, LLC supplied the flight model mechanism to Malin Space Science Systems (MSSS) where it was integrated with electronics and in turn delivered to JPL in October 2008.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133672850","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839632
H. Hua, E. Fetzer, A. Braverman, Seungwon Lee, Mathew Henderson, S. Lewis, V. Dang, M. de la Torre Juárez, A. Guillaume
To simplify access to large and complex satellite data sets for climate analysis and model verification, a service-oriented architecture-based tool was developed to help study long-term and global-scale trends in climate, water and energy cycle, and weather variability. NASA's A-Train satellite constellation set of Level 2 data can be used to enable creation of climatologies that include correlation between observed temperature, water vapor and cloud properties from the A-Train sensors. However, the volume and inhomogeneity of Level 2 data have typically been difficult or time consuming to search and acquire. This tends to result in small-scale or short-term analysis. Instead of imposing on the user an often rigid and limiting web-based analysis environment, we recognize the need for well-designed distributed services so that users can perform analysis in their own familiar computing environments. Voluminous merged Level 2 data containing the various instrument data from the A-Train have recently been generated. Scientists next want to efficiently access selected sets of this merged data and perform their analysis. Server-side capabilities were developed to off-load processing and reduce the amount of data to be transferred to the client. Correspondingly, client-side processing APIs were developed to enable scientists to perform analysis of voluminous server-side data from within their own familiar computing environment (Java, Python, Matlab, IDL, C/C++, and Fortran90).
{"title":"Web services for multiplatform exploratory analysis of level 2 and 3 NEWS merged A-Train data","authors":"H. Hua, E. Fetzer, A. Braverman, Seungwon Lee, Mathew Henderson, S. Lewis, V. Dang, M. de la Torre Juárez, A. Guillaume","doi":"10.1109/AERO.2009.4839632","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839632","url":null,"abstract":"To simplify access to large and complex satellite data sets for climate analysis and model verification, a service-oriented architecture-based tool was developed to help study long-term and global-scale trends in climate, water and energy cycle, and weather variability. NASA's A-Train satellite constellation set of Level 2 data can be used to enable creation of climatologies that include correlation between observed temperature, water vapor and cloud properties from the A-Train sensors. However, the volume and inhomogeneity of Level 2 data have typically been difficult or time consuming to search and acquire. This tends to result in small-scale or short-term analysis. Instead of imposing on the user an often rigid and limiting web-based analysis environment, we recognize the need for well-designed distributed services so that users can perform analysis in their own familiar computing environments. Voluminous merged Level 2 data containing the various instrument data from the A-Train have recently been generated. Scientists next want to efficiently access selected sets of this merged data and perform their analysis. Server-side capabilities were developed to off-load processing and reduce the amount of data to be transferred to the client. Correspondingly, client-side processing APIs were developed to enable scientists to perform analysis of voluminous server-side data from within their own familiar computing environment (Java, Python, Matlab, IDL, C/C++, and Fortran90).","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131899689","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839645
A. Murray, M. Schoppers, Steve F. Scandore
Mars Science Laboratory (MSL), NASA's next mission to Mars, will deploy a large Rover carrying a battery of eleven science instruments, representing a wide variety of payload types. The Rover's flight software (FSW) has the task of monitoring, commanding, collecting, managing and in some cases calibrating data from these instruments. Though the instruments represent a large variety of requirements, complexity, data volumes, fault protection, and commanding logic, the FSW is designed to exploit the commonality among the instruments' requirements in order to maximize reuse of software and to minimize design, implementation and testing effort. To achieve this, we developed an architectural pattern in which all of the common features and patterns of behavior required to manage an instrument are supported, and clear adaptation points are identified and provided to allow expression of the unique behaviors needed for each instrument. For each instrument there is a FSW module called an Instrument Manager (IM), and each of these is an instance of the common pattern. The common IM architecture is expressed in the design as a FSW module called the Instrument Manager Framework (IMF), along with a supporting library for handling instrument communications, the Instrument Manager Library (IML). The IMF module includes a code generator that reads specifications of the ground command set for an instrument, their associated behaviors, and other internal behaviors (e.g. fault response behaviors), expressed in spreadsheets, and produces a set of source code files containing implementations of these commands and behaviors, and their supporting types and variables. The IML module also includes a code generator which transforms a spreadsheet specifying the set of commands that the instrument accepts into C code that parameterizes communications with the instruments. We first describe the instrument management requirements on the Rover FSW, and then continue with an exposition of the IM architectural pattern. We conclude with some statistics on the efficiencies gained in the application of this pattern.
{"title":"A reusable architectural pattern for auto-generated payload management flight software","authors":"A. Murray, M. Schoppers, Steve F. Scandore","doi":"10.1109/AERO.2009.4839645","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839645","url":null,"abstract":"Mars Science Laboratory (MSL), NASA's next mission to Mars, will deploy a large Rover carrying a battery of eleven science instruments, representing a wide variety of payload types. The Rover's flight software (FSW) has the task of monitoring, commanding, collecting, managing and in some cases calibrating data from these instruments. Though the instruments represent a large variety of requirements, complexity, data volumes, fault protection, and commanding logic, the FSW is designed to exploit the commonality among the instruments' requirements in order to maximize reuse of software and to minimize design, implementation and testing effort. To achieve this, we developed an architectural pattern in which all of the common features and patterns of behavior required to manage an instrument are supported, and clear adaptation points are identified and provided to allow expression of the unique behaviors needed for each instrument. For each instrument there is a FSW module called an Instrument Manager (IM), and each of these is an instance of the common pattern. The common IM architecture is expressed in the design as a FSW module called the Instrument Manager Framework (IMF), along with a supporting library for handling instrument communications, the Instrument Manager Library (IML). The IMF module includes a code generator that reads specifications of the ground command set for an instrument, their associated behaviors, and other internal behaviors (e.g. fault response behaviors), expressed in spreadsheets, and produces a set of source code files containing implementations of these commands and behaviors, and their supporting types and variables. The IML module also includes a code generator which transforms a spreadsheet specifying the set of commands that the instrument accepts into C code that parameterizes communications with the instruments. We first describe the instrument management requirements on the Rover FSW, and then continue with an exposition of the IM architectural pattern. We conclude with some statistics on the efficiencies gained in the application of this pattern.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132299319","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839646
S.F. Hishmeh, T. Doering, J. Lumpp
This paper1 2 describes the design, implementation and testing of flight software for KySat-1 a picosatellite scheduled to launch in 2009. The paper also discusses the challenges of developing dependable software in an academic environment and the development of dependable software for commercial off the shelf (COTS) hardware in space applications. Techniques employed to design for reuse and examples of software reuse in recent sub-orbital and near-space missions are also described. The software architecture, software engineering practices, and testing techniques developed for KySat-1 will serve as the basis for a series of future Kentucky Space Consortium missions.
{"title":"Design of flight software for the KySat CubeSat bus","authors":"S.F. Hishmeh, T. Doering, J. Lumpp","doi":"10.1109/AERO.2009.4839646","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839646","url":null,"abstract":"This paper1 2 describes the design, implementation and testing of flight software for KySat-1 a picosatellite scheduled to launch in 2009. The paper also discusses the challenges of developing dependable software in an academic environment and the development of dependable software for commercial off the shelf (COTS) hardware in space applications. Techniques employed to design for reuse and examples of software reuse in recent sub-orbital and near-space missions are also described. The software architecture, software engineering practices, and testing techniques developed for KySat-1 will serve as the basis for a series of future Kentucky Space Consortium missions.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"282 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134495152","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839447
D. Stoker, G. Fathi, P. Ionov, S. Beck
A dual UV, Rayleigh/nitrogen Raman LIDAR system was developed for the purpose of profiling aerosols at vertical ranges between 0.025 and 5 km. The 355 nm LIDAR was operated in El Segundo, California during June and July 2008, during a period of intense wildfire activity in Northern California. From the two independent measurements we calculated the particle backscatter, and using the humidity-corrected LIDAR backscatter-to-extinction ratios given by Ackermann[1] we calculated aerosol optical thickness (AOT) profiles. Preliminary validation studies revealed that under most conditions the calculated LIDAR AOT data agreed with total AOT measured from a collocated sun photometer, except for cases when high-altitude smoke from wildfires was present. To account for high-altitude smoke, a two-layer atmospheric model was assumed, where the lower layer's AOT was calculated using the backscatter-to-extinction method and the high-altitude AOT was found through direct attenuation of the Raman signal. A comparison of AOT measurements from the ground-based LIDAR and the MODIS (Aqua and Terra) overpasses was then performed during the peak period of transport of smoke from Northern California, between 19 June 2008 and 2 July 2008. While the LIDAR and Sun Photometer were found to be in good agreement, it was found that the MODIS overpasses consistently indicated a larger AOT.
{"title":"LIDAR versus satellite-measured optical thickness of a wildfire aerosol","authors":"D. Stoker, G. Fathi, P. Ionov, S. Beck","doi":"10.1109/AERO.2009.4839447","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839447","url":null,"abstract":"A dual UV, Rayleigh/nitrogen Raman LIDAR system was developed for the purpose of profiling aerosols at vertical ranges between 0.025 and 5 km. The 355 nm LIDAR was operated in El Segundo, California during June and July 2008, during a period of intense wildfire activity in Northern California. From the two independent measurements we calculated the particle backscatter, and using the humidity-corrected LIDAR backscatter-to-extinction ratios given by Ackermann[1] we calculated aerosol optical thickness (AOT) profiles. Preliminary validation studies revealed that under most conditions the calculated LIDAR AOT data agreed with total AOT measured from a collocated sun photometer, except for cases when high-altitude smoke from wildfires was present. To account for high-altitude smoke, a two-layer atmospheric model was assumed, where the lower layer's AOT was calculated using the backscatter-to-extinction method and the high-altitude AOT was found through direct attenuation of the Raman signal. A comparison of AOT measurements from the ground-based LIDAR and the MODIS (Aqua and Terra) overpasses was then performed during the peak period of transport of smoke from Northern California, between 19 June 2008 and 2 July 2008. While the LIDAR and Sun Photometer were found to be in good agreement, it was found that the MODIS overpasses consistently indicated a larger AOT.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134559030","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839684
A. Ahmadi, T. Fransson, Anneli Crona, Markus Klein, P. Soderholm
With global cuts in defense budgets, air forces have to sustain the same level of readiness with a reduced number of aircraft. To succeed with this challenge, it is not sufficient to improve current maintenance concepts, but also new ones have to be introduced.
{"title":"Integration of RCM and PHM for the next generation of aircraft","authors":"A. Ahmadi, T. Fransson, Anneli Crona, Markus Klein, P. Soderholm","doi":"10.1109/AERO.2009.4839684","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839684","url":null,"abstract":"With global cuts in defense budgets, air forces have to sustain the same level of readiness with a reduced number of aircraft. To succeed with this challenge, it is not sufficient to improve current maintenance concepts, but also new ones have to be introduced.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133823361","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839406
R. Prabhu, E. Grayver
OFDM is a widely adopted modulation technique for wireless communication. However, the OFDM waveform still suffers from a large peak-to-average power ratio (PAR). Larger PAR leads to higher transmit power inefficiency. In this paper, we compare two constellation modification techniques, constellation distortion (CD) and active constellation extension (ACE), to reduce the PAR of the OFDM waveform. Both techniques are similar, in the sense that the constellation symbols are modified to reduce PAR. In CD, the tradeoff is between PAR reduction and added distortion, which results in a larger bit error rate (BER). In ACE, the tradeoff is between added power and PAR reduction. A metric called normalized total power (NTP) is introduced to facilitate a comparison between these two different techniques. Using this metric, we compare the performance of the two techniques using an 802.11a OFDM waveform. We present comparisons, via simulation, in both coded and uncoded cases. The simulation results show that, for an uncoded OFDM system, ACE performs better than CD for all constellations except QPSK. However, CD is preferred over ACE when coding is present. NTP improvements using CD can be up to 4.1dB in the case of coded QPSK and up to 0.8 dB using ACE for uncoded QPSK.
{"title":"Active constellation modification techniques for OFDM PAR reduction","authors":"R. Prabhu, E. Grayver","doi":"10.1109/AERO.2009.4839406","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839406","url":null,"abstract":"OFDM is a widely adopted modulation technique for wireless communication. However, the OFDM waveform still suffers from a large peak-to-average power ratio (PAR). Larger PAR leads to higher transmit power inefficiency. In this paper, we compare two constellation modification techniques, constellation distortion (CD) and active constellation extension (ACE), to reduce the PAR of the OFDM waveform. Both techniques are similar, in the sense that the constellation symbols are modified to reduce PAR. In CD, the tradeoff is between PAR reduction and added distortion, which results in a larger bit error rate (BER). In ACE, the tradeoff is between added power and PAR reduction. A metric called normalized total power (NTP) is introduced to facilitate a comparison between these two different techniques. Using this metric, we compare the performance of the two techniques using an 802.11a OFDM waveform. We present comparisons, via simulation, in both coded and uncoded cases. The simulation results show that, for an uncoded OFDM system, ACE performs better than CD for all constellations except QPSK. However, CD is preferred over ACE when coding is present. NTP improvements using CD can be up to 4.1dB in the case of coded QPSK and up to 0.8 dB using ACE for uncoded QPSK.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115173169","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839519
K. Siri, M. Willhoff, K. Conner, Duc-Quan Tran
This paper presents a power system consisting of current-mode, shared-bus converters configured as Series-Input, Parallel-Output (SIPO). These current-mode commercial-off-the-shelf (COTS) dc-dc converters transform a 1kV system input voltage into a 5V output with up to 500 Watts of power. The SIPO power system provides for system expansion and preserves the standalone converter's efficiency of over 80%. Uniform input voltage distribution control improves power system reliability by distributing thermal stresses equally among the series-connected converters. Furthermore, robust system stability and uniform input voltage distribution among series-connected converters is realized without control conflict. A computer simulation and an experimental 1 kV 500 W prototype were successfully implemented to validate the uniform voltage distribution power converter architecture.
{"title":"High-voltage-input, low-voltage-output, series-connected converters with uniform voltage distribution","authors":"K. Siri, M. Willhoff, K. Conner, Duc-Quan Tran","doi":"10.1109/AERO.2009.4839519","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839519","url":null,"abstract":"This paper presents a power system consisting of current-mode, shared-bus converters configured as Series-Input, Parallel-Output (SIPO). These current-mode commercial-off-the-shelf (COTS) dc-dc converters transform a 1kV system input voltage into a 5V output with up to 500 Watts of power. The SIPO power system provides for system expansion and preserves the standalone converter's efficiency of over 80%. Uniform input voltage distribution control improves power system reliability by distributing thermal stresses equally among the series-connected converters. Furthermore, robust system stability and uniform input voltage distribution among series-connected converters is realized without control conflict. A computer simulation and an experimental 1 kV 500 W prototype were successfully implemented to validate the uniform voltage distribution power converter architecture.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"2636 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115712797","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839309
M. Pivtoraiko, I. Nesnas, A. Kelly
We present an approach to efficient navigation of autonomous wheeled robots operating in cluttered natural environments. The approach builds upon a popular method of autonomous robot navigation, where desired robot motions are computed using local and global motion planners operating in tandem. A conventional approach to designing the local planner in this setting is to evaluate a fixed number of constant-curvature arc motions and pick one that is the best balance between the quality of obstacle avoidance and minimizing traversed path length to the goal (or a similar measure of operation cost). The presented approach proposes a different set of motion alternatives considered by the local planner. Important performance improvement is achieved by relaxing the assumption that motion alternatives are constant-curvature arcs. We first present a method to measure the quality of local planners in this setting. Further, we identify general techniques of designing improved sets of motion alternatives. By virtue of a minor modification, solely replacing the motions considered by the local planner, our approach offers a measurable performance improvement of dual-planner navigation systems.
{"title":"Autonomous robot navigation using advanced motion primitives","authors":"M. Pivtoraiko, I. Nesnas, A. Kelly","doi":"10.1109/AERO.2009.4839309","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839309","url":null,"abstract":"We present an approach to efficient navigation of autonomous wheeled robots operating in cluttered natural environments. The approach builds upon a popular method of autonomous robot navigation, where desired robot motions are computed using local and global motion planners operating in tandem. A conventional approach to designing the local planner in this setting is to evaluate a fixed number of constant-curvature arc motions and pick one that is the best balance between the quality of obstacle avoidance and minimizing traversed path length to the goal (or a similar measure of operation cost). The presented approach proposes a different set of motion alternatives considered by the local planner. Important performance improvement is achieved by relaxing the assumption that motion alternatives are constant-curvature arcs. We first present a method to measure the quality of local planners in this setting. Further, we identify general techniques of designing improved sets of motion alternatives. By virtue of a minor modification, solely replacing the motions considered by the local planner, our approach offers a measurable performance improvement of dual-planner navigation systems.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"100 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114172809","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839650
N. Kohtake, A. Katoh, N. Ishihama, M. Katahira
The role of flight software in the spacecraft is becoming more essential if missions are to be considered successful.1 2 To realize more reliable and continuous independent verification and validation (IV&V) and improve the dependability of flight software, a systems engineering process called Model-based IV&V (MBIVV) was developed and has been applied to flight software for several years. This paper examines the experience of performing MBIVV, a process which augments existing IV&V methods with various potential benefits to improve the dependability of flight software. MBIVV techniques are effective for detecting basic or complex errors and many warnings, all of which may not be identified in existing IV&V processes. Moreover, the techniques can be applied to all or only the critical portions of the target software. The number, level of abstraction, and scope of the models are adjusted to meet the objectives of the IV&V attribute and the complexity of the target flight software. This paper introduces the MBIVV paradigm, activities, and practical applications to demonstrate that this MBIVV is an effective means of ensuring the dependability of flight software.
{"title":"Model-based independent verification and validation for dependable flight software","authors":"N. Kohtake, A. Katoh, N. Ishihama, M. Katahira","doi":"10.1109/AERO.2009.4839650","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839650","url":null,"abstract":"The role of flight software in the spacecraft is becoming more essential if missions are to be considered successful.1 2 To realize more reliable and continuous independent verification and validation (IV&V) and improve the dependability of flight software, a systems engineering process called Model-based IV&V (MBIVV) was developed and has been applied to flight software for several years. This paper examines the experience of performing MBIVV, a process which augments existing IV&V methods with various potential benefits to improve the dependability of flight software. MBIVV techniques are effective for detecting basic or complex errors and many warnings, all of which may not be identified in existing IV&V processes. Moreover, the techniques can be applied to all or only the critical portions of the target software. The number, level of abstraction, and scope of the models are adjusted to meet the objectives of the IV&V attribute and the complexity of the target flight software. This paper introduces the MBIVV paradigm, activities, and practical applications to demonstrate that this MBIVV is an effective means of ensuring the dependability of flight software.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114611956","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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