2022 IEEE Aerospace Conference (AERO)最新文献

{"title":"Reinforcement Learning-based Anomaly Detection for PHM applications","authors":"Samir Khan, T. Yairi, Shinichi Nakasuka, S. Tsutsumi","doi":"10.1109/AERO53065.2022.9843543","DOIUrl":"https://doi.org/10.1109/AERO53065.2022.9843543","url":null,"abstract":"Prognostics and Health Management (PHM) is an essential requirement for engineering assets. Its processing strategies include modules for the detection, diagnostics and prognostics of known fault conditions. However, during operation, there are always fault conditions that were not anticipated. These events manifest as anomalies and could potentially be catastrophic with the loss of the asset. Anomalies can indicate an impending fault condition, therefore, the automatic identification of anomalies can lead to solving reliability problems that might manifest because of complexities arising from the operating environment and component degradation. Data-driven approaches have gained increasing popularity as a comprehensive anomaly detection method whenever data on nominal and fault conditions is available. However, many supervised learning techniques often face problems whenever models are trained from the limited set of partially labelled anomalies, whilst the rest of the dataset is left unlabelled. An alternative is to use unsupervised learning techniques, that are supposed to obviate stipulating the performance of the anomaly detector. But these still often produce many false positives because of the lack of prior knowledge of true anomalies. Considering this, this article investigates the use of a Reinforcement Learning (RL)-based approach to address the problem of unknown classes of anomalies that might lie beyond the scope of the initially trained model. A Q-learning method is used to exploit the existing data model whilst exploring new classes to improve classification accuracy and optimise decision making. This makes it of significant practical benefit, as anomalies can be unpredictable in form and usually evolve over time. In particular, a deep network-based anomaly detector agent is used to initially learn the action-value function (i.e., the Q-value function) from the limited labelled data. An environment is created for the agent to actively interact not only with the labelled anomalies but also to explore rare and novel unlabelled anomalies that might lie beyond the scope of the initially trained model. A reward function is defined based on the sparse normative content, which stipulates when the agent detects the anomaly state. However, the robustness of this method is still an open question as it simply shifts the anomaly detection responsibility onto the reward function being used. This shows the strong dependence on how the problem state-action space is defined for these methods to perform well.","PeriodicalId":219988,"journal":{"name":"2022 IEEE Aerospace Conference (AERO)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115419390","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}

{"title":"Adapting the Hatley-Pirbhai Method for the Era of SysML and Digital Engineering","authors":"M. Maier","doi":"10.1109/AERO53065.2022.9843384","DOIUrl":"https://doi.org/10.1109/AERO53065.2022.9843384","url":null,"abstract":"The Hatley-Pirbhai method is an integrated approach to model-based systems engineering that was first articulated in the 1980s and actively used and further developed into the early 2010's. Many approaches from the method can be very productively applied to current MBSE and digital engineering efforts and may help to guide the development of complex models and simplify what can otherwise be overwhelming complexity in the choice of models. This paper reviews the key elements of the Hatley-Pirbhai method, discusses how the base method can be adapted to use current notations, and then examines the elements of a longer-term program to integrate the strongest aspects of the methods with current architecture framework concepts.","PeriodicalId":219988,"journal":{"name":"2022 IEEE Aerospace Conference (AERO)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115500209","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}

{"title":"Methods for Evaluation of Human-in-the-Loop Inspection of a Space Station Mockup Using a Quadcopter","authors":"Hannah Weiss, Ansh Patel, Matthew Romano, Brandon Apodoca, Prince Kuevor, E. Atkins, L. Stirling","doi":"10.1109/AERO53065.2022.9843466","DOIUrl":"https://doi.org/10.1109/AERO53065.2022.9843466","url":null,"abstract":"Suited astronauts currently perform visual inspections for external spacecraft damage during extravehicular activity (EVA). Small, free-flying satellites can be used to perform these visual inspection tasks to reduce crew risk by keeping astronauts inside the vehicle. One approach gives the astronaut teleoperational control of the satellite, while another approach is engaging a control system that commands the satellite to fly along an inspection path. We assembled a mockup of a space station (featuring three modules of varying geometry) and used a quadcopter fitted with a GoPro Camera to emulate visual inspection of the mockup by the small satellite. A pilot participant performed the space station inspection task by utilizing the teleoperation mode of the quadcopter. The participant had access to a line-of-sight view of the quadcopter and space station mockup from a distance, and an egocentric view of the testing area (including the mockup) from the quadcopter's onboard camera. The inspection task required the participant to actively scan for, locate, and take pictures of surface anomalies on the space station mockup. Performance was evaluated by determining percentage of anomalies detected, time taken to complete the inspection, and gaze time percentages (physical quadcopter and space station versus camera display). Observations were recorded for the teleoperated flight mode and indicate a strong user preference for an egocentric quadcopter view to support anomaly detection and navigation. In the teleoperated flight mode, the participant had difficulty with accurately and consistently locating anomalies while also navigating and controlling the quadcopter. Global situation awareness abilities and anomaly detection performance were limited, suggesting further research is needed to support human-robot teaming for spacecraft inspection. This preliminary evaluation supports continued data collection with the developed test bed for human-robot interaction with additional levels of automation. Findings from the methods proposed can lead to design recommendations regarding the usage of teleoperated and autonomous flight modes as well as the impact of available viewpoints.","PeriodicalId":219988,"journal":{"name":"2022 IEEE Aerospace Conference (AERO)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116757663","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}

{"title":"The Impacts of Heating Actuators in Extremely Cold Space Environments","authors":"J. Scheidler, Erik J. Stalcup, E. Montbach","doi":"10.1109/AERO53065.2022.9843758","DOIUrl":"https://doi.org/10.1109/AERO53065.2022.9843758","url":null,"abstract":"Conventional, grease-lubricated actuators for space mechanisms can achieve long life but must be heated above about 213 K, or -60 °C, to function in extremely cold environments. This paper first overviews a new NASA project that is developing two rotational actuators that can achieve long life without the need for supplemental heating. Then, the impacts of heating conventional, grease-lubricated actuators are studied for operation in a lunar permanently shadowed region. To facilitate the assessment, a novel total efficiency metric is introduced that relates the average power output to the average total power input (i.e., the power to heat plus the power to actuate/rotate). The assessment employs a thermal analysis of the energy required to heat an actuator from a survival temperature of 30 K to 213 K as well as the power required to subsequently maintain 213 K while in an operational state. Two concepts of actuator operation are considered that separately highlight the impacts of warmup heating energy and maintenance heater power. It is shown that in practical situations, the perceived efficiency of an actuator with 100% conventional operating efficiency can reach 10% or lower, particularly when the actuator has a high emissivity and is operated at lower duty cycles for durations less than 10 hours. Other impacts are presented along with a method of mitigating the impacts in some applications.","PeriodicalId":219988,"journal":{"name":"2022 IEEE Aerospace Conference (AERO)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116890909","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}

{"title":"Sub-Pixel Localization of Objects Using Multiple Spectral Bands","authors":"Mridul Gupta, Sriram Baireddy, J. Chan, Mitchell Krouss, G. Furlich, Paul Martens, Moses W. Chan, M. Comer, E. Delp","doi":"10.1109/AERO53065.2022.9843692","DOIUrl":"https://doi.org/10.1109/AERO53065.2022.9843692","url":null,"abstract":"Most satellite images have adequate spatial resolution and signal-to-noise ratio (SNR) for the detection and localization of common large objects, such as buildings, roads, or bridges in that these objects are described by many pixels that have relatively high SNR. In other applications one wants to be able to localize the position of a single object or closely-spaced objects (CSOs) that are described by only a few pixels (or less than one pixel) with low SNR. In this paper, we describe a method that uses images from multiple spectral bands to increase the accuracy of sub-pixel localization. We assume that the gray level of a pixel is described by a spreading matrix determined by the point spread function of the sensing system. We also assume that we know the approximate location of the observed object or objects in a co-spatially registered 2D neighborhood of each spectral frame. For our experiments we have two spectral bands. We describe a method to estimate the object or objects amplitudes and spatial locations with sub-pixel accuracy using non-linear optimization and information from two spectral bands. We show that our proposed method achieves a higher sub-pixel resolution compared to existing approaches. At a medium SNR (10 dB), we can localize a single object with an error of 0.08 pixels and localize two objects that are separated by 0.7 pixels with an error of 0.11 pixels. We derive the Cramer-Rao Lower Bound and compare the proposed estimator's variance with this bound.","PeriodicalId":219988,"journal":{"name":"2022 IEEE Aerospace Conference (AERO)","volume":"257 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117350124","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}

{"title":"A Comparative Analysis of Energy Management Strategies for a Fuel-Cell Hybrid Electric System UAV","authors":"M. S. Elkerdany, I. Safwat, A. Youssef, M. Elkhatib","doi":"10.1109/AERO53065.2022.9843240","DOIUrl":"https://doi.org/10.1109/AERO53065.2022.9843240","url":null,"abstract":"Hybrid electric UAVs rely heavily on energy manage-ment strategy (EMS). For a small UAV fuel-cell (FC) hybrid system, a comparison of four EMSs is presented in this paper. The FC, lithium-ion battery, and dc/dc converters comprise the hybrid system. The management of hybrid electric power flow based on changes in load power and battery state of charge (SOC) is an important part of these strategies. The energy management schemes considered in this paper are the most commonly used energy management schemes in fuel-cell based UAVs, and they include the following: the classical proportional-integral (PI) control (CPIC) strategy, the state machine control (SMC) strategy, the rule-based fuzzy logic (RBFL) strategy, and an intelligent technique based on adaptive neuro-fuzzy control strategy (ANFIS). There are two primary metrics for comparing performance, hydrogen consumption and battery SOC (BSOC), which impacts their life cycle. Such an EMS should be designed to maximise fuel efficiency while also making sure each energy source is used responsibly. MATLAB/Simulink software is used to conduct an in-depth study of a simulated model. For better usage of hybrid system's energy, EMS identifies variations in transient load current, as well as fuel-cell power. These investi-gations give insight on EMS work and the power flow in hybrid power systems. The trade-off choice between EMS is ensuring optimal performance in accordance with selected criterion.","PeriodicalId":219988,"journal":{"name":"2022 IEEE Aerospace Conference (AERO)","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127079354","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}

{"title":"A High Voltage Tethered Power System for Planetary Surface Applications","authors":"Ansel Barchowsky, A. Amirahmadi, K. Botteon, G. Carr, C. Jin, P. McGarey, Shelly Sposato, Summer Yang","doi":"10.1109/AERO53065.2022.9843731","DOIUrl":"https://doi.org/10.1109/AERO53065.2022.9843731","url":null,"abstract":"In the pursuit of human and robotic expansion of the Lunar surface and other planetary bodies, power conversion and transmission over long distances has emerged as a distinct need. The ability to transmit power over kilometers at high efficiency enables human settlement, in-situ resource utilization, and extreme terrain robotic exploration, through the ability to reach previously unreachable places. The critical building blocks of such a system are being developed by the Tethered Power System for Lunar Mobility and Power Transmission (TYMPO) project, a NASA project aimed at reaching flight readiness by 2024. This paper presents an architectural and requirements overview of the TYMPO project, along with technology discussions on the GaN-based multilevel DCX converters, dual fiber optics and power-line communications system, and high-voltage tether. Finally, a set of proposed future missions will be presented, mapping the capabilities of the TYMPO system to missions that may soon explore planetary surfaces throughout the solar system.","PeriodicalId":219988,"journal":{"name":"2022 IEEE Aerospace Conference (AERO)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125000456","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}

{"title":"Night Sky Testing of the Lunar Flashlight Star Tracker","authors":"D. Sternberg, Kevin Lo, J. Baker","doi":"10.1109/AERO53065.2022.9843416","DOIUrl":"https://doi.org/10.1109/AERO53065.2022.9843416","url":null,"abstract":"Lunar Flashlight (LF) is a 6U, 14 kg spacecraft being built by the NASA Jet Propulsion Laboratory (JPL). The mission will use IR laser technology to search for volatiles and surface water ice deposits in the permanently shadowed regions (PSR) of the moon in preparation for future human lunar exploration. The fine pointing provided by the Guidance, Navigation and Control (GNC) system is crucial for the spacecraft to successfully reach the moon, enter a lunar orbit, and acquire scientific data. At the center of the GNC system's ability to determine the spacecraft's attitude is a star tracker. The LF star tracker is a commercial-off-the-shelf (COTS) unit built into the integrated GNC system provided by Blue Canyon Technologies. Blue Canyon tested the star tracker in a lab environment for basic functionality and attitude estimation capabilities; upon delivery of the hardware to JPL, further testing with a real night sky was desired to determine expected in-flight operational characteristics. JPL maintains the Table Mountain Facility with its suite of ground telescopes, including a 0.6m telescope with an equatorial mount. This stable platform provided a highly accurate method of providing slews and attitude holds akin to what the spacecraft will perform in flight. Therefore, by analyzing the data from these representative night-sky ground tests performed in March, 2021, it is possible to acquire expected flight performance of the star tracker, particularly in regard to the ability of the star tracker to maintain lock on the starfield during planned maneuver types. This paper presents the various tests that have been performed to ensure that the LF star tracker will function as part of the overall GNC system and integrated spacecraft once launched. Test data is included for several key tests, and a path forward towards future integration and testing at the spacecraft level is described.","PeriodicalId":219988,"journal":{"name":"2022 IEEE Aerospace Conference (AERO)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125877984","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}

{"title":"Trajectory-based generic chassis control framework for the MMX-Rover","authors":"Walter Schindler, R. Krenn","doi":"10.1109/AERO53065.2022.9843333","DOIUrl":"https://doi.org/10.1109/AERO53065.2022.9843333","url":null,"abstract":"Martian Moons eXploration (MMX) is a joint project of the French, German and Japanese space agencies Centre national d'etudes spatiales (CNES), German Aerospace Center (DLR) and Japan Aerospace Exploration Agency (JAXA) for an exploration mission to the moons of Mars, i.e. Phobos and Deimos. CNES and DLR are providing a rover payload to the mother spacecraft of JAXA which is designated to be the first rover to drive in milli-g-environment. Locomotion in milli-g-environment on potentially hazardous terrain with steep slopes and high sinkage raises increased demands on the locomotion subsystem and control algorithms. The MMX-Rover chassis control algorithms (CCA) are embedded as part of the MMX-Rover locomotion software partition in a three layer architecture between the Command and Control Software and the hardware-related Basic Software. This paper proposes a trajectory-based generic chassis control framework as extended chassis control variant for the MMX-Rover. The rover locomotion possibilities are formulated upon a generic rover motion interface to derive analytical solutions for the specialized MMX-Rover locomotion modes. The resulting algebraic chassis control algorithms (A-CCA) are mathematically formulated in detail. A connection to meta-modelling for kinematic locomotion functions is established. The generic chassis control framework can be used to formulate the onboard control algorithms as minimal application code or generic application code. The decision between the minimal or generic code formulation variant practically influences the control software architecture and implementation. The generic chassis control framework is used as a practical analysis and verification tool to ensure the qualification of a geometrically inspired and kinematically simplified control algorithm variant (G-CCA) as flight software candidate. In particular, the algebraic equations originating from the generic chassis control framework are compared to the geometric control algorithms regarding their functional scope, kinematic formulation and practical software implementation. Results for the analysis and verification of G-CCA are shown and their qualification in terms of the locomotion functional coverage and rover motion behavior discussed. The generic chassis control framework contributes to ensure and enhance the functioning and quality of the control algorithms in the MMX-Rover mission context.","PeriodicalId":219988,"journal":{"name":"2022 IEEE Aerospace Conference (AERO)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125889510","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}

{"title":"Building a lifeboat: MSL's uplink and installation campaign to restore a failing backup computer","authors":"A. Holloway, Nick Peper, A. Anabtawi, Jack Quade, D. Byrne","doi":"10.1109/AERO53065.2022.9843266","DOIUrl":"https://doi.org/10.1109/AERO53065.2022.9843266","url":null,"abstract":"Flight software updates are among the hardest and most dangerous activities for the Mars Science Laboratory (MSL) Curiosity team. While danger is often mitigated by backups, fallback strategies, and incremental installation with ground-in-the-loop cycles which provide a safety net for the installation process, the software update described in this paper was unable to use many of the common practices due to the nature of the fault addressed by the update. The MSL rover (landed August 2012) encountered a problem with one of its computer's non-volatile storage chips in 2019, requiring a swap to its backup computer and an urgent software upgrade called R-Hope. R-Hope, a lifeboat to be used in the event of primary computer issues, was written, tested, and sent to the rover in lightning speed of just 19 months. Multi-mission and team coordination allowed the 49 flight software image files to be uplinked to the rover over a 6-week period, using multiple paths and backup options for speedy delivery. In the end, the R-Hope software upgrade returned the computer to operation as a backup flight computer. The flight software transition was designed to impact science return as little as possible, and installation plans included science activities for the majority of MSL instruments. This paper describes the uplink and installation campaigns for R-Hope, and discusses the notable lessons learned by the operations team.","PeriodicalId":219988,"journal":{"name":"2022 IEEE Aerospace Conference (AERO)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125941168","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}