Pub Date : 2020-03-01DOI: 10.1109/AERO47225.2020.9172686
J. Wallace, Dylan Mckeithen, E. Serabyn, Alex Ramirez
Digital holographic microscopy is well suited to the search for microbial species due in part to its intrinsic stability, volumetric imaging capability, and sensitivity to very dilute samples. This is all done with a system having no moving parts, making it additionally attractive for flight instrumentation. Our devices have been field tested on several occasions, and have demonstrated robustness to extreme conditions. When bacteria are alive and moving, they are easy to detect. However, some measurements are subtler. Can we distinguish between a live yet nonmotile species and a mineral, for instance? To provide another method of discrimination, we have added the ability to measure object polarization. This will allow us to characterize the sample by polarization state without any sacrifice in the spatial or temporal resolution (<1um at 15 Hz). This snapshot polarization sensing is a new method for characterizing the sample under test. In this paper, we will describe the instrument design, the laboratory tests, and demonstrate its performance with live bacteria and crystalline samples.
{"title":"Polarization sensing in digital holographic microscopy","authors":"J. Wallace, Dylan Mckeithen, E. Serabyn, Alex Ramirez","doi":"10.1109/AERO47225.2020.9172686","DOIUrl":"https://doi.org/10.1109/AERO47225.2020.9172686","url":null,"abstract":"Digital holographic microscopy is well suited to the search for microbial species due in part to its intrinsic stability, volumetric imaging capability, and sensitivity to very dilute samples. This is all done with a system having no moving parts, making it additionally attractive for flight instrumentation. Our devices have been field tested on several occasions, and have demonstrated robustness to extreme conditions. When bacteria are alive and moving, they are easy to detect. However, some measurements are subtler. Can we distinguish between a live yet nonmotile species and a mineral, for instance? To provide another method of discrimination, we have added the ability to measure object polarization. This will allow us to characterize the sample by polarization state without any sacrifice in the spatial or temporal resolution (<1um at 15 Hz). This snapshot polarization sensing is a new method for characterizing the sample under test. In this paper, we will describe the instrument design, the laboratory tests, and demonstrate its performance with live bacteria and crystalline samples.","PeriodicalId":114560,"journal":{"name":"2020 IEEE Aerospace Conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115119870","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 : 2020-03-01DOI: 10.1109/AERO47225.2020.9172450
R. Ashtari, I. Linscott, C. Hersman
Very-long baseline interferometry (VLBI) allows for exceptionally high-resolution imaging in radio astronomy. Ultimately the angular resolution of radio interferometers and telescopes is determined by the separation between antennas in the array. Building on this fundamental concept, potential uses of existing spacecraft radio systems for VLBI are explored. Coherent observations performed between ground radio telescopes (GRT) and spacecraft require stringent drift tolerances for timing and synchronization between the GRT and spacecraft. Observed data using the spacecraft antenna is then recorded and stored on-board before downlink. Among candidate spacecraft, a promising contender and focus of this paper is New Horizons. Currently at a distance greater than 45 AU, New Horizons offers an outstanding baseline for astronomical radio observation and provides necessary, configurable instrumentation for performing an extended baseline observation in conjunction with a GRT or other spacecraft. Communications with New Horizons are synchronized with a 30 MHz clock signal using an ultra-stable oscillator (USO), providing an exceptional Allan Deviation of $3times 10^{-13}$ per one second integration time. Of the instruments on-board New Horizons, the Radio Science Experiment (REX) is of particular interest for its potential towards VLBI application. Developed for atmospheric measurements during occultations between the 7.182 GHz uplink from the 70 meter NASA Deep Space Network (DSN) antenna and Pluto/Charon, REX also successfully performed axial radiometric measurements of the Cygnus-A and Cassiopeia-A galaxies using the New Horizons high-gain antenna (HGA). The REX instrument's infusion with the New Horizons HGA allows for any radio measurement to be recorded, stored on-board, and ultimately to be downlinked to the DSN. For VLBI, New Horizons could receive command data for timed three-dimensional alignment synchronous to a ground-based observation. The observed data would then be recorded, downlinked, correlated, and processed for synthesized imaging. Using New Horizons for VLBI would be a proof-of-concept. With a fixed observation frequency, narrow bandwidth and receiver sensitivity of −177 dBm, New Horizons is limited as an extension for long-baseline radio interferometry. Given these restrictions, a successful VLBI measurement using New Horizons would still result in the highest angular resolution for any radio observation ever, at an astonishing 1.34 nanoarcseconds. Expanding the applications of New Horizons to VLBI observations encourages collaboration within the growing infrastructure for space-based astronomy.
{"title":"Using Existing Spacecraft towards Long Baselines in VLBI","authors":"R. Ashtari, I. Linscott, C. Hersman","doi":"10.1109/AERO47225.2020.9172450","DOIUrl":"https://doi.org/10.1109/AERO47225.2020.9172450","url":null,"abstract":"Very-long baseline interferometry (VLBI) allows for exceptionally high-resolution imaging in radio astronomy. Ultimately the angular resolution of radio interferometers and telescopes is determined by the separation between antennas in the array. Building on this fundamental concept, potential uses of existing spacecraft radio systems for VLBI are explored. Coherent observations performed between ground radio telescopes (GRT) and spacecraft require stringent drift tolerances for timing and synchronization between the GRT and spacecraft. Observed data using the spacecraft antenna is then recorded and stored on-board before downlink. Among candidate spacecraft, a promising contender and focus of this paper is New Horizons. Currently at a distance greater than 45 AU, New Horizons offers an outstanding baseline for astronomical radio observation and provides necessary, configurable instrumentation for performing an extended baseline observation in conjunction with a GRT or other spacecraft. Communications with New Horizons are synchronized with a 30 MHz clock signal using an ultra-stable oscillator (USO), providing an exceptional Allan Deviation of $3times 10^{-13}$ per one second integration time. Of the instruments on-board New Horizons, the Radio Science Experiment (REX) is of particular interest for its potential towards VLBI application. Developed for atmospheric measurements during occultations between the 7.182 GHz uplink from the 70 meter NASA Deep Space Network (DSN) antenna and Pluto/Charon, REX also successfully performed axial radiometric measurements of the Cygnus-A and Cassiopeia-A galaxies using the New Horizons high-gain antenna (HGA). The REX instrument's infusion with the New Horizons HGA allows for any radio measurement to be recorded, stored on-board, and ultimately to be downlinked to the DSN. For VLBI, New Horizons could receive command data for timed three-dimensional alignment synchronous to a ground-based observation. The observed data would then be recorded, downlinked, correlated, and processed for synthesized imaging. Using New Horizons for VLBI would be a proof-of-concept. With a fixed observation frequency, narrow bandwidth and receiver sensitivity of −177 dBm, New Horizons is limited as an extension for long-baseline radio interferometry. Given these restrictions, a successful VLBI measurement using New Horizons would still result in the highest angular resolution for any radio observation ever, at an astonishing 1.34 nanoarcseconds. Expanding the applications of New Horizons to VLBI observations encourages collaboration within the growing infrastructure for space-based astronomy.","PeriodicalId":114560,"journal":{"name":"2020 IEEE Aerospace Conference","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116968403","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 : 2020-03-01DOI: 10.1109/AERO47225.2020.9172339
Tony Licari, Navid Ataei, H. Ochoa
Pointing stability of spacecraft payloads is a vital part of ensuring high quality science return. This is especially true for fly-by missions that rely on precise pointing knowledge and control among a suite of elements to provide appropriate co-alignment between both optical and in-situ instruments. The Europa Clipper mission plans to execute over 45 fly-bys of Jupiter's moon Europa. To do this, the spacecraft will be put into highly elliptical orbits around Jupiter. Throughout each orbit, the Clipper spacecraft will experience a variety of thermal environments near 5 AU. It will be commanded to operate in a wide range of power cycles, experience cold soaks of up to nine hours in eclipse, then immediately be impacted by direct solar flux, and ultimately pass within 25km of Europa's icy surface. The most stressing duration for the spacecraft from a distortion perspective will be within +/-48 hours of closest approach to the Europan surface, due to the increased power demand from the instruments on the Nadir-pointed deck, as well as the electronic boxes in the Avionics Vault. Despite the structural distortions due to evolving thermal environments and demanding power schedules, the spacecraft is expected to maintain adequate pointing of its instruments throughout the orbit, especially during the fly-by, where the majority of science is captured. The objective of this work is to identify the driving thermal scenarios and analyze the Spacecraft-level thermal-mechanical distortions. The Europa Clipper Mechanical and Thermal teams have analyzed the thermal gradients of the Clipper spacecraft throughout an entire orbit of Jupiter. This transient analysis included appropriate power profiles, spacecraft attitudes and external albedo loads of orbit E41 of the 17F12v2 mission schedule. A thermal model (TM) of the spacecraft was linked to the NASTRAN structural finite element model (FEM). Thirty strategic points along the orbit were selected to map thermal gradients from the TM to the FEM and assess distortion of the structures. This integrated modeling and analysis effort provided confidence in the mechanical system design of the Europa Clipper spacecraft. Sensitive areas were then highlighted, which led to design modifications, aimed to provide thermal-mechanical stability robustness moving forward. This paper will discuss the modeling and analysis approach, results, design improvements, and lessons learned.
{"title":"Thermal-Mechanical Stability of a Large Spacecraft Structure within a Jovian Orbit","authors":"Tony Licari, Navid Ataei, H. Ochoa","doi":"10.1109/AERO47225.2020.9172339","DOIUrl":"https://doi.org/10.1109/AERO47225.2020.9172339","url":null,"abstract":"Pointing stability of spacecraft payloads is a vital part of ensuring high quality science return. This is especially true for fly-by missions that rely on precise pointing knowledge and control among a suite of elements to provide appropriate co-alignment between both optical and in-situ instruments. The Europa Clipper mission plans to execute over 45 fly-bys of Jupiter's moon Europa. To do this, the spacecraft will be put into highly elliptical orbits around Jupiter. Throughout each orbit, the Clipper spacecraft will experience a variety of thermal environments near 5 AU. It will be commanded to operate in a wide range of power cycles, experience cold soaks of up to nine hours in eclipse, then immediately be impacted by direct solar flux, and ultimately pass within 25km of Europa's icy surface. The most stressing duration for the spacecraft from a distortion perspective will be within +/-48 hours of closest approach to the Europan surface, due to the increased power demand from the instruments on the Nadir-pointed deck, as well as the electronic boxes in the Avionics Vault. Despite the structural distortions due to evolving thermal environments and demanding power schedules, the spacecraft is expected to maintain adequate pointing of its instruments throughout the orbit, especially during the fly-by, where the majority of science is captured. The objective of this work is to identify the driving thermal scenarios and analyze the Spacecraft-level thermal-mechanical distortions. The Europa Clipper Mechanical and Thermal teams have analyzed the thermal gradients of the Clipper spacecraft throughout an entire orbit of Jupiter. This transient analysis included appropriate power profiles, spacecraft attitudes and external albedo loads of orbit E41 of the 17F12v2 mission schedule. A thermal model (TM) of the spacecraft was linked to the NASTRAN structural finite element model (FEM). Thirty strategic points along the orbit were selected to map thermal gradients from the TM to the FEM and assess distortion of the structures. This integrated modeling and analysis effort provided confidence in the mechanical system design of the Europa Clipper spacecraft. Sensitive areas were then highlighted, which led to design modifications, aimed to provide thermal-mechanical stability robustness moving forward. This paper will discuss the modeling and analysis approach, results, design improvements, and lessons learned.","PeriodicalId":114560,"journal":{"name":"2020 IEEE Aerospace Conference","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117344867","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 : 2020-03-01DOI: 10.1109/AERO47225.2020.9172667
Arun Kumar, M. Bell, Benjamin J. Mellinkoff, Alex Sandoval, Wendy Bailey Martin, J. Burns
Low-latency telerobotics can enable more intricate surface tasks on extraterrestrial planetary bodies than has ever been previously attempted. In order for humanity to create a sustainable lunar presence, well-developed collaboration between humans and robots is necessary to perform complex tasks. This paper presents a methodology to assess the human factors, situational awareness (SA) and cognitive load (CL), associated with teleoperated assembly tasks. Currently, telerobotic assembly on an extraterrestrial body has never been attempted, and a valid methodology to assess the associated human factors has not been developed. The Telerobotics Laboratory at the University of Colorado-Boulder created the Telerobotic Simulation System (TSS) which enables remote operation of a rover and a robotic arm. The TSS was used in a laboratory experiment designed as an analog to a lunar mission. The operator's task was to assemble a radio interferometer. Each participant completed this task under two conditions, remote teleoperation (limited SA) and local operation (optimal SA). The goal of this experiment was to establish a methodology to accurately measure the operator's SA and CL while performing teleoperated assembly tasks. A successful methodology would yield results showing greater SA and lower CL while operating locally. Performance metrics measured in this experiment showed greater SA and lower CL in the local environment, supported by a 27% increase in the mean time to completion of the assembly task when operating remotely. Subjective measurements of SA and CL did not align with the performance metrics. This brought into question the validity of the subjective assessments used in this experiment when applied to telerobotic assembly tasks. Results from this experiment will guide future work attempting to accurately quantify the human factors associated with telerobotic assembly. Once an accurate methodology has been developed, we will be able to measure how new variables affect an operator's SA and CL in order to optimize the efficiency and effectiveness of telerobotic assembly tasks.
{"title":"A Methodology to Assess the Human Factors Associated with Lunar Teleoperated Assembly Tasks","authors":"Arun Kumar, M. Bell, Benjamin J. Mellinkoff, Alex Sandoval, Wendy Bailey Martin, J. Burns","doi":"10.1109/AERO47225.2020.9172667","DOIUrl":"https://doi.org/10.1109/AERO47225.2020.9172667","url":null,"abstract":"Low-latency telerobotics can enable more intricate surface tasks on extraterrestrial planetary bodies than has ever been previously attempted. In order for humanity to create a sustainable lunar presence, well-developed collaboration between humans and robots is necessary to perform complex tasks. This paper presents a methodology to assess the human factors, situational awareness (SA) and cognitive load (CL), associated with teleoperated assembly tasks. Currently, telerobotic assembly on an extraterrestrial body has never been attempted, and a valid methodology to assess the associated human factors has not been developed. The Telerobotics Laboratory at the University of Colorado-Boulder created the Telerobotic Simulation System (TSS) which enables remote operation of a rover and a robotic arm. The TSS was used in a laboratory experiment designed as an analog to a lunar mission. The operator's task was to assemble a radio interferometer. Each participant completed this task under two conditions, remote teleoperation (limited SA) and local operation (optimal SA). The goal of this experiment was to establish a methodology to accurately measure the operator's SA and CL while performing teleoperated assembly tasks. A successful methodology would yield results showing greater SA and lower CL while operating locally. Performance metrics measured in this experiment showed greater SA and lower CL in the local environment, supported by a 27% increase in the mean time to completion of the assembly task when operating remotely. Subjective measurements of SA and CL did not align with the performance metrics. This brought into question the validity of the subjective assessments used in this experiment when applied to telerobotic assembly tasks. Results from this experiment will guide future work attempting to accurately quantify the human factors associated with telerobotic assembly. Once an accurate methodology has been developed, we will be able to measure how new variables affect an operator's SA and CL in order to optimize the efficiency and effectiveness of telerobotic assembly tasks.","PeriodicalId":114560,"journal":{"name":"2020 IEEE Aerospace Conference","volume":"48 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120868581","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 : 2020-03-01DOI: 10.1109/AERO47225.2020.9172755
M. Ivanco, C. Jones
The formulation of science-driven space mission concepts is challenging – possibly even more so than the development and production of the space systems themselves. The formulation of these missions involves defining science objectives, surveying the state of the art of instrument capabilities, documenting the Program of Record and forecasting satellite lifetimes, defining feasible alternatives for spacecraft platforms and access to space, and identifying potentially enabled applications to cite only some of the tasks faced by mission design teams. The trade space is vast, especially in an era of novel platform concepts where constellations of SmallSats are changing the current paradigm of spaceborne observations. A crucial component of the formulation of science mission concepts is the assessment of the alternatives defined in this trade space. The assessment of the concepts is so complex that a heuristic approach does not sufficiently articulates the benefits of the alternatives under consideration. This complexity can be attributed to several factors. Science missions have to satisfy multiple science goals and their associated science objectives, therefore entering the realm of multi-criteria decision problems. In addition, multiple instruments, platforms, launchers, and ground system options are combined to define the architectures. The alternatives under assessment in these multi-criteria decision problems are numerous, as are the possible components of the segments that make up the architectures. Finally, stakeholders involved in the design and assessment of these science mission concepts have varying value systems: priorities relevant to stakeholders vary from group to group based on interests, objectives, and experiences. The complexity is such that the assessment requires a deliberate and structured approach to provide a comprehensive assessment of the mission concepts. This paper presents an approach that enables the assessment of the science benefits achieved by a space mission concept in the formulation phase. The approach combines Utility and Quality assessments provided by Subject Matter Experts to produce a Science Benefit score for each identified science objective. The paper discusses how this approach was tailored for the assessment of Observing Systems in the Aerosols, Cloud, Convection, and Precipitation (ACCP) study. In this Earth Science application, Utility quantifies how important a given geophysical variable is to addressing an identified science objective, while Quality quantifies how well an architecture obtains a geophysical variable with respect to Minimum levels listed in the Science Traceability Matrix. The resulting Benefit score articulates the science capability of a given architecture to address a given objective. This paper also presents the processes implemented to obtain the assessments from Subject Matter Experts in the ACCP study.
{"title":"Assessing the Science Benefit of Space Mission Concepts in the Formulation Phase","authors":"M. Ivanco, C. Jones","doi":"10.1109/AERO47225.2020.9172755","DOIUrl":"https://doi.org/10.1109/AERO47225.2020.9172755","url":null,"abstract":"The formulation of science-driven space mission concepts is challenging – possibly even more so than the development and production of the space systems themselves. The formulation of these missions involves defining science objectives, surveying the state of the art of instrument capabilities, documenting the Program of Record and forecasting satellite lifetimes, defining feasible alternatives for spacecraft platforms and access to space, and identifying potentially enabled applications to cite only some of the tasks faced by mission design teams. The trade space is vast, especially in an era of novel platform concepts where constellations of SmallSats are changing the current paradigm of spaceborne observations. A crucial component of the formulation of science mission concepts is the assessment of the alternatives defined in this trade space. The assessment of the concepts is so complex that a heuristic approach does not sufficiently articulates the benefits of the alternatives under consideration. This complexity can be attributed to several factors. Science missions have to satisfy multiple science goals and their associated science objectives, therefore entering the realm of multi-criteria decision problems. In addition, multiple instruments, platforms, launchers, and ground system options are combined to define the architectures. The alternatives under assessment in these multi-criteria decision problems are numerous, as are the possible components of the segments that make up the architectures. Finally, stakeholders involved in the design and assessment of these science mission concepts have varying value systems: priorities relevant to stakeholders vary from group to group based on interests, objectives, and experiences. The complexity is such that the assessment requires a deliberate and structured approach to provide a comprehensive assessment of the mission concepts. This paper presents an approach that enables the assessment of the science benefits achieved by a space mission concept in the formulation phase. The approach combines Utility and Quality assessments provided by Subject Matter Experts to produce a Science Benefit score for each identified science objective. The paper discusses how this approach was tailored for the assessment of Observing Systems in the Aerosols, Cloud, Convection, and Precipitation (ACCP) study. In this Earth Science application, Utility quantifies how important a given geophysical variable is to addressing an identified science objective, while Quality quantifies how well an architecture obtains a geophysical variable with respect to Minimum levels listed in the Science Traceability Matrix. The resulting Benefit score articulates the science capability of a given architecture to address a given objective. This paper also presents the processes implemented to obtain the assessments from Subject Matter Experts in the ACCP study.","PeriodicalId":114560,"journal":{"name":"2020 IEEE Aerospace Conference","volume":"157 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120934154","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 : 2020-03-01DOI: 10.1109/AERO47225.2020.9172475
William C. Gallagher, B. Shirgur, G. Gefke
The design of the robot subsystem of NASA's Asteroid Redirect Mission presented the unique challenge of retrieving a 20-ton boulder sized sample from the surface of a near Earth asteroid using multiple robot arms mounted to vehicle capable of touching down on the surface of the asteroid. The robot arms planned for use on the mission were based on heritage from Mars rovers and Restore-L satellite servicing to aid in meeting mass, cost, and schedule goals, which put constraints on the design and led to the use of light weight, low stiffness robot arms. The design of the rest of the Capture Module (CAPM) relied on an extensive analysis of the load capability of the robot arms, which utilized a high fidelity model of the robot arm subsystem to evaluate a large number of extraction scenarios and identify impactful modifications to the system that would increase the probably of mission success.
{"title":"Analysis of the Robot Subsystem Capability for Boulder Extraction in the Asteroid Redirect Mission","authors":"William C. Gallagher, B. Shirgur, G. Gefke","doi":"10.1109/AERO47225.2020.9172475","DOIUrl":"https://doi.org/10.1109/AERO47225.2020.9172475","url":null,"abstract":"The design of the robot subsystem of NASA's Asteroid Redirect Mission presented the unique challenge of retrieving a 20-ton boulder sized sample from the surface of a near Earth asteroid using multiple robot arms mounted to vehicle capable of touching down on the surface of the asteroid. The robot arms planned for use on the mission were based on heritage from Mars rovers and Restore-L satellite servicing to aid in meeting mass, cost, and schedule goals, which put constraints on the design and led to the use of light weight, low stiffness robot arms. The design of the rest of the Capture Module (CAPM) relied on an extensive analysis of the load capability of the robot arms, which utilized a high fidelity model of the robot arm subsystem to evaluate a large number of extraction scenarios and identify impactful modifications to the system that would increase the probably of mission success.","PeriodicalId":114560,"journal":{"name":"2020 IEEE Aerospace Conference","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121353824","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 : 2020-03-01DOI: 10.1109/AERO47225.2020.9172351
M. Müller, Eric Falk, J. Meira, Redouane Sassioui, Radu Sate
Civil aviation, be it for passengers or cargo, is a highly competitive market, airlines are therefore strongly driven to increase earnings and reduce costs. The maintenance of the aircraft fleet is one pivotal aspect of this. In the industry two types of events occur, scheduled and unscheduled maintenance. While normal scheduled maintenance is already expensive, unscheduled maintenance events are even more so. The potential for savings is paramount when unscheduled events can be reduced to a minimum. Additionally, the safety of the customers is a huge concern, which is why possible failures ought to be detected as soon as possible. Over the last years, the large amounts of data that became available over the last decade open then door to a new range of applications. It got possible to learn from the past to predict future events, detect abnormal changes or behaviors, based on newly generated data. In this work we describe the application of anomaly detection on aircraft data. The goal is to predict upcoming failures of the turbine's hydraulic pumps, having severe financial implications should they be replaced in a context of unscheduled maintenance. In this context, we describe how we addressed this challenging task, and how crucial expert knowledge is when approaching such difficult undertakings. With our dataset we studied multiple outlier detection methods, ST-DBSCAN has proven to be the best suited method for this use case. We show how we identified the correct data frames to apply the methodology, and evaluate its prediction performance on a real-world dataset from several aircrafts.
{"title":"Predicting Failures in 747–8 Aircraft Hydraulic Pump Systems","authors":"M. Müller, Eric Falk, J. Meira, Redouane Sassioui, Radu Sate","doi":"10.1109/AERO47225.2020.9172351","DOIUrl":"https://doi.org/10.1109/AERO47225.2020.9172351","url":null,"abstract":"Civil aviation, be it for passengers or cargo, is a highly competitive market, airlines are therefore strongly driven to increase earnings and reduce costs. The maintenance of the aircraft fleet is one pivotal aspect of this. In the industry two types of events occur, scheduled and unscheduled maintenance. While normal scheduled maintenance is already expensive, unscheduled maintenance events are even more so. The potential for savings is paramount when unscheduled events can be reduced to a minimum. Additionally, the safety of the customers is a huge concern, which is why possible failures ought to be detected as soon as possible. Over the last years, the large amounts of data that became available over the last decade open then door to a new range of applications. It got possible to learn from the past to predict future events, detect abnormal changes or behaviors, based on newly generated data. In this work we describe the application of anomaly detection on aircraft data. The goal is to predict upcoming failures of the turbine's hydraulic pumps, having severe financial implications should they be replaced in a context of unscheduled maintenance. In this context, we describe how we addressed this challenging task, and how crucial expert knowledge is when approaching such difficult undertakings. With our dataset we studied multiple outlier detection methods, ST-DBSCAN has proven to be the best suited method for this use case. We show how we identified the correct data frames to apply the methodology, and evaluate its prediction performance on a real-world dataset from several aircrafts.","PeriodicalId":114560,"journal":{"name":"2020 IEEE Aerospace Conference","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124937581","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 : 2020-03-01DOI: 10.1109/AERO47225.2020.9172554
S. Sonkar, Prashant Kumar, Deepu Philip, A. K. Ghosh
Generally, surveillance refers to a single, known and mostly static point of interest that is observed for a predetermined amount of time. Similarly, reconnaissance implies a large area to be covered thereby requiring rapid mobility and capability to observe multiple points of interest. Real-time video surveillance is a good way to realize both surveillance and reconnaissance, which involves multiple challenges and complexities; viz., computational efficiency, latency, image quality, etc. The concept of utilizing a fixed-wing VTOL Unmanned Aerial Vehicle (UAV) is more appropriate than the conventional fixed-wing UAV or multi-rotors, in terms of the quality of visual imageries, increased operational range, reduced time to target and thereby reduced mission times, minimal dependencies on infrastructure, and so on. This research studies the application of a fixed-wing VTOL UAV for real-time low-latency monitoring systems for reconnaissance; thereby quantifying various benefits, including the practical performance of such a video surveillance system. The simulation required for this research is realized using a Robot Operating System (ROS) and the final model is validated using both hardware and software.
{"title":"Low-Cost Smart Surveillance and Reconnaissance Using VTOL Fixed Wing UAV","authors":"S. Sonkar, Prashant Kumar, Deepu Philip, A. K. Ghosh","doi":"10.1109/AERO47225.2020.9172554","DOIUrl":"https://doi.org/10.1109/AERO47225.2020.9172554","url":null,"abstract":"Generally, surveillance refers to a single, known and mostly static point of interest that is observed for a predetermined amount of time. Similarly, reconnaissance implies a large area to be covered thereby requiring rapid mobility and capability to observe multiple points of interest. Real-time video surveillance is a good way to realize both surveillance and reconnaissance, which involves multiple challenges and complexities; viz., computational efficiency, latency, image quality, etc. The concept of utilizing a fixed-wing VTOL Unmanned Aerial Vehicle (UAV) is more appropriate than the conventional fixed-wing UAV or multi-rotors, in terms of the quality of visual imageries, increased operational range, reduced time to target and thereby reduced mission times, minimal dependencies on infrastructure, and so on. This research studies the application of a fixed-wing VTOL UAV for real-time low-latency monitoring systems for reconnaissance; thereby quantifying various benefits, including the practical performance of such a video surveillance system. The simulation required for this research is realized using a Robot Operating System (ROS) and the final model is validated using both hardware and software.","PeriodicalId":114560,"journal":{"name":"2020 IEEE Aerospace Conference","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124990201","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 : 2020-03-01DOI: 10.1109/AERO47225.2020.9172293
Somrita Banerjee, T. Lew, Riccardo Bonalli, Abdulaziz Alfaadhel, Ibrahim Abdulaziz Alomar, Hesham M. Shageer, M. Pavone
Sequential convex programming (SCP) has recently emerged as an effective tool to quickly compute locally optimal trajectories for robotic and aerospace systems alike, even when initialized with an unfeasible trajectory. In this paper, by focusing on the Guaranteed Sequential Trajectory Optimization (GuSTO) algorithm, we propose a methodology to accelerate SCP-based algorithms through warm-starting. Specifically, leveraging a dataset of expert trajectories from GuSTO, we devise a neural-network-based approach to predict a locally optimal state and control trajectory, which is used to warm-start the SCP algorithm. This approach allows one to retain all the theoretical guarantees of GuSTO while simultaneously taking advantage of the fast execution of the neural network and reducing the time and number of iterations required for GuSTO to converge. The result is a faster and theoretically guaranteed trajectory optimization algorithm.
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Pub Date : 2020-03-01DOI: 10.1109/AERO47225.2020.9172758
Lucas I. Finn, Steven Schoenecker, L. Bookman, John Grimes
Maintaining tracks on High-Value Targets (HVTs) in dense multi-target environments remains a computationally challenging problem. Approaches must trade off hypothesis management with state estimation accuracy in the presence of finite sensing and computational capabilities. This problem becomes more difficult when sensors provide additional, infrequent features: information that correlates track states over long timescales such as target size and color, or unique identifiers such as a license plate. Traditional real-time Multi-Hypothesis Tracking (MHT) algorithms must prune hypotheses before feature information arrives, often removing the correct association hypothesis from the solution space. Graph-Based Track stitching (GBT) algorithms suffer from two related problems: they rely on an upstream tracking algorithm to correctly associate measurements across short timescales, and must still associate tracks in the presence of infrequent feature information. As a result, the HVT tracking problem requires correctly assigning reports to tracks on both short and long timescales. In this paper, we extend the Approximate Track Automata (ATA) algorithm to perform dynamic hypothesis management given a set of HVT hypotheses and feature information models. The original ATA algorithm applied a single strategy to manage the entire hypothesis space; we tailor that approach here given HVTs and target features. We compare traditional tracking metrics such as root mean square error, probability of track, and track purity for HVT and background targets. In addition, we investigate the effect of scaling the number of Integer Linear Program (ILP) variables, i.e. the number of MHT and ATA hypotheses, on these metrics. Interestingly, we note that while solving ILPs is (in general) NP-complete, the ILP constraint matrices and cost vectors contain structure that often results in efficient runtimes in practice. We offer possible explanations as to why the ILP problem structure allows this near-polynomial runtime.
{"title":"Approximate Track Automata - Combining the Best of MHT and GBT for High Value Target Tracking","authors":"Lucas I. Finn, Steven Schoenecker, L. Bookman, John Grimes","doi":"10.1109/AERO47225.2020.9172758","DOIUrl":"https://doi.org/10.1109/AERO47225.2020.9172758","url":null,"abstract":"Maintaining tracks on High-Value Targets (HVTs) in dense multi-target environments remains a computationally challenging problem. Approaches must trade off hypothesis management with state estimation accuracy in the presence of finite sensing and computational capabilities. This problem becomes more difficult when sensors provide additional, infrequent features: information that correlates track states over long timescales such as target size and color, or unique identifiers such as a license plate. Traditional real-time Multi-Hypothesis Tracking (MHT) algorithms must prune hypotheses before feature information arrives, often removing the correct association hypothesis from the solution space. Graph-Based Track stitching (GBT) algorithms suffer from two related problems: they rely on an upstream tracking algorithm to correctly associate measurements across short timescales, and must still associate tracks in the presence of infrequent feature information. As a result, the HVT tracking problem requires correctly assigning reports to tracks on both short and long timescales. In this paper, we extend the Approximate Track Automata (ATA) algorithm to perform dynamic hypothesis management given a set of HVT hypotheses and feature information models. The original ATA algorithm applied a single strategy to manage the entire hypothesis space; we tailor that approach here given HVTs and target features. We compare traditional tracking metrics such as root mean square error, probability of track, and track purity for HVT and background targets. In addition, we investigate the effect of scaling the number of Integer Linear Program (ILP) variables, i.e. the number of MHT and ATA hypotheses, on these metrics. Interestingly, we note that while solving ILPs is (in general) NP-complete, the ILP constraint matrices and cost vectors contain structure that often results in efficient runtimes in practice. We offer possible explanations as to why the ILP problem structure allows this near-polynomial runtime.","PeriodicalId":114560,"journal":{"name":"2020 IEEE Aerospace Conference","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125131910","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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