scholarly journals R2U2: Tool Overview

10.29007/5pch ◽  
2018 ◽  
Author(s):  
Kristin Yvonne Rozier ◽  
Johann Schumann
Keyword(s):  
Health Management ◽  
Autonomous Systems ◽  
Building Blocks ◽  
Unmanned Aerial Systems ◽  
Critical System ◽  
Safety Critical System ◽  
Target Architecture ◽  
Wide Range ◽  
Aerial Systems ◽  
Temporal Formula

R2U2 (Realizable, Responsive, Unobtrusive Unit) is an extensible framework for runtime System Health Management (SHM) of cyber-physical systems. R2U2 can be run in hardware (e.g., FPGAs), or software; can monitor hardware, software, or a combination of the two; and can analyze a range of different types of system requirements during runtime. An R2U2 requirement is specified utilizing a hierarchical combination of building blocks: temporal formula runtime observers (in LTL or MTL), Bayesian networks, sensor filters, and Boolean testers. Importantly, the framework is extensible; it is designed to enable definitions of new building blocks in combination with the core structure. Originally deployed on Unmanned Aerial Systems (UAS), R2U2 is designed to run on a wide range of embedded platforms, from autonomous systems like rovers, satellites, and robots, to human-assistive ground systems and cockpits.R2U2 is named after the requirements it satisfies; while the exact requirements vary by platform and mission, the ability to formally reason about Realizability, Responsiveness, and Unobtrusiveness is necessary for flight certifiability, safety-critical system assurance, and achievement of technology readiness levels for target systems. Realizability ensures that R2U2 is sufficiently expressive to encapsulate meaningful runtime requirements while maintaining adaptability to run on different platforms, transition be- tween different mission stages, and update quickly between missions. Responsiveness entails continuously monitoring the system under test, real-time reasoning, reporting intermediate status, and as-early-as-possible requirements evaluations. Unobtrusiveness ensures compliance with the crucial properties of the target architecture: functionality, certifiability, timing, tolerances, cost, or other constraints.

scholarly journals Towards Real-time, On-board, Hardware-supported Sensor and Software Health Management for Unmanned Aerial Systems

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Johann Schumann ◽  
Kristin Y. Rozier ◽  
Thomas Reinbacher ◽  
Ole J. Mengshoel ◽  
Timmy Mbaya ◽  
...  
Keyword(s):  
Real Time ◽  
Health Management ◽  
Building Blocks ◽  
Unmanned Aerial Systems ◽  
Gate Arrays ◽  
Novel Approach ◽  
Field Programmable ◽  
Programmable Gate Arrays ◽  
Onboard System ◽  
Aerial Systems

For unmanned aerial systems (UAS) to be successfully deployed and integrated within the national airspace, it is imperative that they possess the capability to effectively complete their missions without compromising the safety of other aircraft, as well as persons and property on the ground. This necessity creates a natural requirement for UAS that can respondto uncertain environmental conditions and emergent failures in real-time, with robustness and resilience close enough to those of manned systems. We introduce a system that meets this requirement with the design of a real-time onboard system health management (SHM) capability to continuously monitor sensors, software, and hardware components. This system can detect and diagnose failures and violations of safety or performance rules during the flight of a UAS. Our approach to SHM is three-pronged, providing: (1) real-time monitoring of sensor and software signals; (2) signal analysis, preprocessing, and advanced on-the-fly temporal and Bayesian probabilistic fault diagnosis; and (3) an unobtrusive, lightweight, read-only, low-power realization using Field Programmable Gate Arrays (FPGAs) that avoids overburdening limited computing resources or costly re-certification of flight software. We call this approach rt-R2U2, a name derived from its requirements. Our implementation provides a novel approach of combining modular building blocks, integrating responsive runtime monitoring of temporal logic system safety requirements with model-based diagnosis and Bayesian network-based probabilistic analysis. We demonstrate this approach using actual flight data from theNASA Swift UAS.

scholarly journals Design and Evaluation of Sensor Housing for Boundary Layer Profiling Using Multirotors

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2481 ◽  
Author(s):  
Ashraful Islam ◽  
Adam L. Houston ◽  
Ajay Shankar ◽  
Carrick Detweiler
Keyword(s):  
Boundary Layer ◽  
High Speed ◽  
Ground Level ◽  
Radiation Shielding ◽  
Unmanned Aerial Systems ◽  
Heat Sources ◽  
Wide Range ◽  
Artificial Heat ◽  
Aerial Systems ◽  
Airborne Sensors

Traditional configurations for mounting Temperature–Humidity (TH) sensors on multirotor Unmanned Aerial Systems (UASs) often suffer from insufficient radiation shielding, exposure to mixed and turbulent air from propellers, and inconsistent aspiration while situated in the wake of the UAS. Descent profiles using traditional methods are unreliable (when compared to an ascent profile) due to the turbulent mixing of air by the UAS while descending into that flow field. Consequently, atmospheric boundary layer profiles that rely on such configurations are bias-prone and unreliable in certain flight patterns (such as descent). This article describes and evaluates a novel sensor housing designed to shield airborne sensors from artificial heat sources and artificial wet-bulbing while pulling air from outside the rotor wash influence. The housing is mounted above the propellers to exploit the rotor-induced pressure deficits that passively induce a high-speed laminar airflow to aspirate the sensor consistently. Our design is modular, accommodates a variety of other sensors, and would be compatible with a wide range of commercially available multirotors. Extensive flight tests conducted at altitudes up to 500 m Above Ground Level (AGL) show that the housing facilitates reliable measurements of the boundary layer phenomena and is invariant in orientation to the ambient wind, even at high vertical/horizontal speeds (up to 5 m/s) for the UAS. A low standard deviation of errors shows a good agreement between the ascent and descent profiles and proves our unique design is reliable for various UAS missions.

Toward Risk-Informed Operation of Autonomous Vehicles to Increase Resilience in Unknown and Dangerous Environments

2016 ◽  
Author(s):  
Zachary Mimlitz ◽  
Adam Short ◽  
Douglas L. Van Bossuyt
Keyword(s):  
Autonomous Vehicles ◽  
Health Management ◽  
Space Exploration ◽  
Autonomous Systems ◽  
Risk Attitude ◽  
Local Area ◽  
Behavioral Risk ◽  
Risk Averse ◽  
Critical System ◽  
Scientific Mission

Operation of autonomous and semi-autonomous systems in hostile and expensive-to-access environments requires great care and a risk-informed operating mentality to protect critical system assets. Space exploration missions, such as the Mars Exploration Rover systems Opportunity and Curiosity, are very costly and difficult to replace. These systems are operated in a very risk-averse manner to preserve the functionality of the systems. By constraining system operations to risk-averse activities, scientific mission goals cannot be achieved if they are deemed too risky. We present a quantifiable method that increases the lifetime efficiency of obtaining scientific goals via the implementation of the Goal-Oriented, Risk Attitude-Driven Reward Optimization (GORADRO) method and a case study conducted with simulated testing of the method. GORADRO relies upon local area information obtained by the system during operations and internal Prognostics and Health Management (PHM) information to determine system health and potential localized risks such as areas where a system may become trapped (e.g.: sand pits, overhangs, overly steep slopes, etc.) while attempting to access scientific mission objectives through using an adaptable operating risk attitude. The results of our simulations and hardware validation using GORADRO show a large increase in the lifetime performance of autonomous rovers in a variety of environments, terrains, and situations given a sufficiently tuned set of risk attitude parameters. Through designing a GORADRO behavioral risk attitude set of parameters, it is possible to increase system resilience in unknown and dangerous environments encountered in space exploration and other similarly hazardous environments.

scholarly journals Quality Assessment of Photogrammetric Methods—A Workflow for Reproducible UAS Orthomosaics

2020 ◽  
Vol 12 (22) ◽  
pp. 3831
Author(s):  
Marvin Ludwig ◽  
Christian M. Runge ◽  
Nicolas Friess ◽  
Tiziana L. Koch ◽  
Sebastian Richter ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Spatial Data ◽  
Forest Canopy ◽  
Cost Effective ◽  
Temporal Analysis ◽  
Unmanned Aerial Systems ◽  
Wide Range ◽  
Very High Spatial Resolution ◽  
Multi Temporal ◽  
Aerial Systems

Unmanned aerial systems (UAS) are cost-effective, flexible and offer a wide range of applications. If equipped with optical sensors, orthophotos with very high spatial resolution can be retrieved using photogrammetric processing. The use of these images in multi-temporal analysis and the combination with spatial data imposes high demands on their spatial accuracy. This georeferencing accuracy of UAS orthomosaics is generally expressed as the checkpoint error. However, the checkpoint error alone gives no information about the reproducibility of the photogrammetrical compilation of orthomosaics. This study optimizes the geolocation of UAS orthomosaics time series and evaluates their reproducibility. A correlation analysis of repeatedly computed orthomosaics with identical parameters revealed a reproducibility of 99% in a grassland and 75% in a forest area. Between time steps, the corresponding positional errors of digitized objects lie between 0.07 m in the grassland and 0.3 m in the forest canopy. The novel methods were integrated into a processing workflow to enhance the traceability and increase the quality of UAS remote sensing.

scholarly journals Design and Development Autonomous Unmanned Aerial Vehicle Software

2020 ◽  
Vol 9 (4) ◽  
pp. 2105-2108
Keyword(s):  
Autonomous Navigation ◽  
Application Programming Interface ◽  
Detection Algorithm ◽  
Mission Planning ◽  
Unmanned Aerial Systems ◽  
Localization And Mapping ◽  
Wide Range ◽  
Human Operators ◽  
Emergency Scenarios ◽  
Aerial Systems

Unmanned aerial vehicles are the cutting edge technology which is used in various arduous applications and emergency scenarios. But human operators find it burdensome and experience a lot of physical and mental stress while operating the aerial systems in critical and emergency scenarios such as rescue operations, mine inspection, and surveillance. Our proposed idea is to provide the autonomous capability and features to these automatons by developing a mission-planning application that can autonomously guide UAV operations even in GPS denied environments by implementing SLAM (Simultaneous Localization and Mapping). With autonomous capability, aerial systems can help to plummet the stress on human operators or may even perform the process or mission efficiently without human intervention in numerous applications. Applications involving autonomous unmanned aerial systems have increased in recent times and are being applied in a wide range of fields such as infrastructure, transport, agriculture, mining, media, and transport. This paper covers the working of the autonomous navigation algorithm, artificially intelligent object detection algorithm and the mission planning API (Application Programming Interface).

scholarly journals Preliminary study towards the definition of a PHM framework for the hydraulic system of a fly-by-wire helicopter

2020 ◽  
Vol 12 (1) ◽  
pp. 13
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli
Keyword(s):  
Flight Control ◽  
Hydraulic System ◽  
Preliminary Analysis ◽  
Failure Modes ◽  
Health Management ◽  
Management Approach ◽  
Critical System ◽  
Wide Range ◽  
The Subject ◽  
Definition Of

On-board hydraulic systems are tasked to provide a number of critical functions to ensure the in-flight operability of rotary-wings vehicles; the hydraulic plant is required to supply power to the flight control actuators and utilities, as well as condition the hydraulic fluid, under a wide range of possible in-service conditions. Being a flight-critical system, the definition of a Prognostics and Health Management framework would provide significant advantages to the users, such as better risk mitigation, improved availability and a reduction in the occurrences of unpredicted failures which still represent one of the more known downsides of helicopters. A preliminary analysis on the effects of the inception and progression of several degradation types is the first step towards assessing if such PHM system is feasible, and which failure modes are more likely to be observed. Moreover, since several key components are frequently provided by different suppliers to the airframer, this preliminary analysis would allow to better assess if an Integrated Vehicle Health Management approach, integrating signals coming from different components, could be beneficial. To pursue this study, a complete model of the hydraulic system for a fly-by-wire helicopter has been prepared. Then, an in-depth simulation campaign was pursued with the aim of studying the interactions between different failure modes, the effects that the propagating degradations have on the system performances and which signals can be used to define a robust set of features. The paper introduces the case-study under analysis, a general configuration for fly-by-wire helicopters, presenting the most prominent peculiarities of the system and the effect of such peculiarities on the definition of health monitoring schemes. The model is then used to describe the behavior of the system under nominal and degraded conditions is introduced. Between the possible failure modes, the interaction between wear in several mechanical components and the occlusion of the hydraulic lines filters was chosen as the subject of this study; motivations are provided and the degradation model described in detail. Hence, results of a wide-ranging simulation campaign are presented, where the time-domain response of the system is used to guide in the definition of a proper set of features able to characterize the selected fault cases. Selected features are presented, chosen according to significant metrics such as correlation with the simulated degradations, signal-to-noise ratio and accuracy. Two different approaches with a varying degree of integration between system signals are proposed and compared. Prognostics is then pursued through well-known particle filter algorithms. The analysis provides promising results on the capability of successfully detecting, isolating and identifying the selected fault mode; laying the foundations for further and more comprehensive studies on the subject.

scholarly journals Inferring the rules of social interaction in migrating caribou

2018 ◽  
Vol 373 (1746) ◽  
pp. 20170385 ◽  
Author(s):  
Colin J. Torney ◽  
Myles Lamont ◽  
Leon Debell ◽  
Ryan J. Angohiatok ◽  
Lisa-Marie Leclerc ◽  
...  
Keyword(s):  
Decision Making ◽  
Social Interactions ◽  
Cultural Transmission ◽  
Movement Ecology ◽  
Unmanned Aerial Systems ◽  
Use Patterns ◽  
Wide Range ◽  
Nature Of Information ◽  
Victoria Island ◽  
Aerial Systems

Social interactions are a significant factor that influence the decision-making of species ranging from humans to bacteria. In the context of animal migration, social interactions may lead to improved decision-making, greater ability to respond to environmental cues, and the cultural transmission of optimal routes. Despite their significance, the precise nature of social interactions in migrating species remains largely unknown. Here we deploy unmanned aerial systems to collect aerial footage of caribou as they undertake their migration from Victoria Island to mainland Canada. Through a Bayesian analysis of trajectories we reveal the fine-scale interaction rules of migrating caribou and show they are attracted to one another and copy directional choices of neighbours, but do not interact through clearly defined metric or topological interaction ranges. By explicitly considering the role of social information on movement decisions we construct a map of near neighbour influence that quantifies the nature of information flow in these herds. These results will inform more realistic, mechanism-based models of migration in caribou and other social ungulates, leading to better predictions of spatial use patterns and responses to changing environmental conditions. Moreover, we anticipate that the protocol we developed here will be broadly applicable to study social behaviour in a wide range of migratory and non-migratory taxa. This article is part of the theme issue ‘Collective movement ecology’.

scholarly journals Probabilistic safety assessment (PSA) of a safety critical system: a case study of a nuclear power plant

2018 ◽  
Vol 7 (2.12) ◽  
pp. 210
Author(s):  
Vinay Kumar ◽  
Dewanshu Pratihar ◽  
Anil Kumar Tripathi
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Safety Assessment ◽  
Critical System ◽  
Probabilistic Safety Assessment ◽  
Safety Critical ◽  
Safety Critical System ◽  
Wide Range ◽  
Probabilistic Safety

Probabilistic Safety Assessment approach has been successfully applied in engineering, economics, computer science and statistics to re-solve a wide range of safety-related problems. However, using Probabilistic Safety Assessment for quantifying safety of a safety critical system is a challenging task in Safety Engineering community. This method plays an essential role in analyzing safety of safety critical sys-tems and its various components. Therefore, in this paper, we present Probabilistic Safety Assessment framework which can be used to quantify the critical failures of a systems. The approach is well demonstrated on a Digital Feed Water Control System uses in a Nuclear Power Plant as safety critical system. 

scholarly journals Urban Unmanned Aerial Systems Operations

2020 ◽  
Vol 36 (2) ◽  
pp. 1-12 ◽  
Author(s):  
Eleonora Bassi
Keyword(s):  
The United States ◽  
Daily Basis ◽  
Economic Benefits ◽  
Point Of View ◽  
Unmanned Aerial Systems ◽  
The European Union ◽  
The United Kingdom ◽  
Wide Range ◽  
Delivery Services ◽  
Aerial Systems

The drone sector offers a wide range of affordances, opportunities, and economic benefits for society. Delivery services, agriculture monitoring, wildfire control, public infrastructure inspections, humanitarian aid, or drone journalism, are among the activities enhanced by unmanned aerial systems (UAS). No surprise the civilian UAS market is growing fast throughout the world. Yet, on a daily basis, newspapers report serious concerns for people infringing other people’s rights through the use of drones. Cybersecurity attacks, data theft, criminal offences brought about the use of this technology frame the picture. Nowadays, several countries are changing their legal rules to properly address such challenges. In 2018, the European Union (EU) started its five year-long regulative process that should establish the common rules and standards for UAS operations within the EU Single Sky by 2023. A similar timeline has been adopted in the United States, so as to provide the jurisdictional boundaries for the civilian use of drones. The United Kingdom (UK) and Japan are adopting new rules too. From a legal point of view, the overall framework is thus rapidly evolving. The aim of this paper is to give attention to (i) privacy and data protection concerns raised by UAS operations; (ii) their monitoring functions and corresponding surveillance issues; and, (iii) how a privacy preserving approach – such as with privacy by design technologies, organizational measures, audit procedures, civic involvement, to name a few – makes a lawful and ethical use of this powerful technology possible.

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