Probabilistic Risk-Based Operational Safety Bound for Rotary-Wing Unmanned Aircraft Systems Traffic Management

2020 ◽  
Vol 17 (3) ◽  
pp. 171-181
Author(s):  
Jueming Hu ◽  
Heinz Erzberger ◽  
Kai Goebel ◽  
Yongming Liu
Keyword(s):  
Traffic Management ◽  
Unmanned Aircraft ◽  
Unmanned Aircraft Systems ◽  
Aircraft Systems ◽  
Operational Safety ◽  
Rotary Wing ◽  
Probabilistic Risk

The state of the art and operational scenarios for urban air mobility with unmanned aircraft

2021 ◽  
pp. 1-30
Author(s):  
F. D. Maia ◽  
J. M. Lourenço da Saúde
Keyword(s):  
Traffic Management ◽  
State Of The Art ◽  
Unmanned Aircraft ◽  
Unmanned Aircraft Systems ◽  
Civil Aviation ◽  
Management Systems ◽  
Urban Air ◽  
Aircraft Systems ◽  
Starting Point ◽  
Standards And Regulations

ABSTRACT A state-of-the-art review of all the developments, standards and regulations associated with the use of major unmanned aircraft systems under development is presented. Requirements and constraints are identified by evaluating technologies specific to urban air mobility, considering equivalent levels of safety required by current and future civil aviation standards. Strategies, technologies and lessons learnt from remotely piloted aviation and novel unmanned traffic management systems are taken as the starting point to assess operational scenarios for autonomous urban air mobility.

scholarly journals A Performance-Based Airspace Model for Unmanned Aircraft Systems Traffic Management

Aerospace ◽  
2020 ◽  
Vol 7 (11) ◽  
pp. 154
Author(s):  
Nichakorn Pongsakornsathien ◽  
Suraj Bijjahalli ◽  
Alessandro Gardi ◽  
Angus Symons ◽  
Yuting Xi ◽  
...  
Keyword(s):  
Traffic Management ◽  
Performance Metrics ◽  
Situational Awareness ◽  
Central Business District ◽  
Unmanned Aircraft ◽  
Unmanned Aircraft Systems ◽  
Global Navigation Satellite Systems ◽  
Communication Overhead ◽  
Satellite Systems ◽  
Aircraft Systems

Recent evolutions of the Unmanned Aircraft Systems (UAS) Traffic Management (UTM) concept are driving the introduction of new airspace structures and classifications, which must be suitable for low-altitude airspace and provide the required level of safety and flexibility, particularly in dense urban and suburban areas. Therefore, airspace classifications and structures need to evolve based on appropriate performance metrics, while new models and tools are needed to address UTM operational requirements, with an increasing focus on the coexistence of manned and unmanned Urban Air Mobility (UAM) vehicles and associated Communication, Navigation and Surveillance (CNS) infrastructure. This paper presents a novel airspace model for UTM adopting Performance-Based Operation (PBO) criteria, and specifically addressing urban airspace requirements. In particular, a novel airspace discretisation methodology is introduced, which allows dynamic management of airspace resources based on navigation and surveillance performance. Additionally, an airspace sectorisation methodology is developed balancing the trade-off between communication overhead and computational complexity of trajectory planning and re-planning. Two simulation case studies are conducted: over the skyline and below the skyline in Melbourne central business district, utilising Global Navigation Satellite Systems (GNSS) and Automatic Dependent Surveillance-Broadcast (ADS-B). The results confirm that the proposed airspace sectorisation methodology promotes operational safety and efficiency and enhances the UTM operators’ situational awareness under dense traffic conditions introducing a new effective 3D airspace visualisation scheme, which is suitable both for mission planning and pre-tactical UTM operations. Additionally, the proposed performance-based methodology can accommodate the diversity of infrastructure and vehicle performance requirements currently envisaged in the UTM context. This facilitates the adoption of this methodology for low-level airspace integration of UAS (which may differ significantly in terms of their avionics CNS capabilities) and set foundations for future work on tactical online UTM operations.

scholarly journals Integration of Unmanned Aircraft Systems into the National Airspace System-Efforts by the University of Alaska to Support the FAA/NASA UAS Traffic Management Program

2020 ◽  
Vol 12 (19) ◽  
pp. 3112
Author(s):  
Michael Hatfield ◽  
Catherine Cahill ◽  
Peter Webley ◽  
Jessica Garron ◽  
Rebecca Beltran
Keyword(s):  
Traffic Management ◽  
Federal Aviation Administration ◽  
The United States ◽  
Lessons Learned ◽  
Unmanned Aircraft ◽  
Unmanned Aircraft Systems ◽  
National Airspace System ◽  
Great Opportunity ◽  
Aircraft Systems ◽  
The University

Over the past decade Unmanned Aircraft Systems (UAS, aka “drones”) have become pervasive, touching virtually all aspects of our world. While UAS offer great opportunity to better our lives and strengthen economies, at the same time these can significantly disrupt manned flight operations and put our very lives in peril. Balancing the demanding and competing requirements of safely integrating UAS into the United States (US) National Airspace System (NAS) has been a top priority of the Federal Aviation Administration (FAA) for several years. This paper outlines efforts taken by the FAA and the National Aeronautics and Space Administration (NASA) to create the UAS Traffic Management (UTM) system as a means to address this capability gap. It highlights the perspectives and experiences gained by the University of Alaska Fairbanks (UAF) Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) as one of the FAA’s six UAS test sites participating in the NASA-led UTM program. The paper summarizes UAF’s participation in the UTM Technical Capability Level (TCL1-3) campaigns, including flight results, technical capabilities achieved, lessons learned, and continuing challenges regarding the implementation of UTM in the NAS. It also details future efforts needed to enable practical Beyond-Visual-Line-of-Sight (BVLOS) flights for UAS operations in rural Alaska.

scholarly journals The Impact of Sensor Response and Airspeed on the Representation of the Convective Boundary Layer and Airmass Boundaries by Small Unmanned Aircraft Systems

2018 ◽  
Vol 35 (8) ◽  
pp. 1687-1699 ◽  
Author(s):  
Adam L. Houston ◽  
Jason M. Keeler
Keyword(s):  
Boundary Layer ◽  
Convective Boundary Layer ◽  
Sensor Response ◽  
Unmanned Aircraft ◽  
Unmanned Aircraft Systems ◽  
Lapse Rate ◽  
Convective Boundary ◽  
Aircraft Systems ◽  
The Impact ◽  
Rotary Wing

AbstractThe objective of the research presented is to assess the impact of sensor response and aircraft airspeed on the accuracy of in situ observations collected by small unmanned aircraft systems profiling the convective boundary layer or transecting airmass boundaries. Estimates are made using simulated aircraft flown within large-eddy simulations. Both instantaneous errors (differences between observed temperature, which include the effects of sensor response and airspeed, and actual temperature) and errors in representation (differences between serial observations and representative snapshots of the atmospheric state) are considered. Synthetic data are retrieved assuming a well-aspirated first-order sensor mounted on rotary-wing aircraft operated as profilers in a simulated CBL and fixed-wing aircraft operated through transects across a simulated airmass boundary. Instantaneous errors are found to scale directly with sensor response time and airspeed for both CBL and airmass boundary experiments. Maximum errors tend to be larger for airmass boundary transects compared to the CBL profiles. Instantaneous errors for rotary-wing aircraft profiles in the CBL simulated for this work are attributable to the background lapse rate and not to turbulent temperature perturbations. For airmass boundary flights, representation accuracy is found to degrade with decreasing airspeed. This signal is most pronounced for flights that encounter the density current wake. When representation errors also include instantaneous errors resulting from sensor response, instantaneous errors are found to be dominant for flights that remain below the turbulent wake. However, for flights that encounter the wake, sensor response times generally need to exceed ~5 s before instantaneous errors become larger than errors in representation.

scholarly journals A Method for Selecting Strategic Deployment Opportunities for Unmanned Aircraft Systems (UAS) for Transportation Agencies

Drones ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 29
Author(s):  
Sarah Hubbard ◽  
Bryan Hubbard
Keyword(s):  
Technology Acceptance ◽  
Traffic Management ◽  
Quality Function Deployment ◽  
Unmanned Aircraft ◽  
Unmanned Aircraft Systems ◽  
Aircraft Systems ◽  
Readiness Level ◽  
Acceptance Model ◽  
Transportation Agencies ◽  
Uas Applications

Unmanned aircraft systems (UAS) are increasingly used for a variety of applications by state Departments of Transportation (DOT) and local transportation agencies due to technology advancements, lower costs, and regulatory changes that have simplified operations. There are numerous applications (e.g., bridge inspection, traffic management, incident response, construction and roadway mapping) and agencies find it challenging to prioritize which applications are most appropriate. Important factors to consider when prioritizing UAS applications include: (1) benefits, (2) ease of adoption, (3) stakeholder acceptance, and (4) technical feasibility. These factors can be evaluated utilizing various techniques such as the technology acceptance model, benefit analysis, and technology readiness level (TRL). This paper presents the methodology and results for the prioritization of UAS applications’ quality function deployment (QFD), which reflects both qualitative and quantitative components. The proposed framework can be used in the future as technologies mature, and the prioritization can be revised on a regular basis to identify future strategic implementation opportunities. Numerous transportation agencies have begun to use UAS, some have developed UAS operating policies and manuals, but there has been no documentation to support identification of the UAS applications that are most appropriate for deployment. This paper fills that gap and documents a method for identification of UAS applications for strategic deployment and illustrates the method with a case study.

scholarly journals Environmental and Sensor Integration Influences on Temperature Measurements by Rotary-Wing Unmanned Aircraft Systems

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1470 ◽  
Author(s):  
Brian Greene ◽  
Antonio Segales ◽  
Tyler Bell ◽  
Elizabeth Pillar-Little ◽  
Phillip Chilson
Keyword(s):  
Unmanned Aircraft ◽  
The Body ◽  
Unmanned Aircraft Systems ◽  
Sensor Integration ◽  
Heat Sources ◽  
Aircraft Systems ◽  
Ducted Fan ◽  
Rotary Wing

Obtaining thermodynamic measurements using rotary-wing unmanned aircraft systems (rwUAS) requires several considerations for mitigating biases from the aircraft and its environment. In this study, we focus on how the method of temperature sensor integration can impact the quality of its measurements. To minimize non-environmental heat sources and prevent any contamination coming from the rwUAS body, two configurations with different sensor placements are proposed for comparison. The first configuration consists of a custom quadcopter with temperature and humidity sensors placed below the propellers for aspiration. The second configuration incorporates the same quadcopter design with sensors instead shielded inside of an L-duct and aspirated by a ducted fan. Additionally, an autopilot algorithm was developed for these platforms to face them into the wind during flight for kinematic wind estimations. This study will utilize in situ rwUAS observations validated against tower-mounted reference instruments to examine how measurements are influenced both by the different configurations as well as the ambient environment. Results indicate that both methods of integration are valid but the below-propeller configuration is more susceptible to errors from solar radiation and heat from the body of the rwUAS.

scholarly journals Considerations for temperature sensor placement on rotary-wing unmanned aircraft systems

2018 ◽  
Author(s):  
Brian R. Greene ◽  
Antonio R. Segales ◽  
Sean Waugh ◽  
Simon Duthoit ◽  
Phillip B. Chilson
Keyword(s):  
Frictional Heating ◽  
Sensor Placement ◽  
Unmanned Aircraft ◽  
Unmanned Aircraft Systems ◽  
Heat Sources ◽  
Aircraft Systems ◽  
Series Of Experiments ◽  
Rotary Wing ◽  
Viable Method

Abstract. With their recent surge in commercial accessibility, rotary-wing unmanned aircraft systems (rwUAS) are proving to be a viable method of atmospheric sensing and sampling while improving upon the shortcomings of traditional methods. To maximize the potential for these platforms to provide reliable observations, it is imperative to have an understanding of their strengths and limitations under varying environmental conditions. This study focuses on the quality of measurements relative to sensor locations on board rwUAS. Typically, thermistors require aspiration and proper siting free of heat sources to make representative measurements of the atmosphere. In an effort to characterize ideal locations for sensor placement, a series of experiments were conducted in the homogeneous environment of an indoor chamber with a pedestal-mounted rwUAS. A suite of thermistors along with a wind probe were mounted inside of a solar shield, which was affixed to a linear actuator arm. The actuator arm was configured such that the sensors within the solar shield would travel underneath the platform into and out of the propeller wash. The actuator arm was displaced horizontally underneath the platform while the motors were throttled to 50 percent, yielding a time series of temperature and wind speed which could be compared to temperatures being collected in the ambient environment. Results indicate that temperatures may be biased on the order of 0.5–1.0 °C and vary appreciably without aspiration, sensors placed close to the tips of the rotors may experience biases due to frictional and compressional heating as a result of turbulent fluctuations, and sensors in proximity to motors may experience biases approaching 1 °C. From these trials, it has been determined that sensor placement underneath a propeller on an rwUAS a distance of one quarter the length of the propeller from the tip is most likely to be minimally impacted from influences of turbulence and motor, compressional, and frictional heating while still maintaining adequate airflow. When opting to use rotor wash as a means for sensor aspiration, the user must be cognizant of these potential sources of platform-induced heating when determining sensor location.

scholarly journals Investigation of Rotor–Airframe Interaction Noise Associated with Small-Scale Rotary-Wing Unmanned Aircraft Systems

2020 ◽  
Vol 65 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Nikolas S. Zawodny ◽  
Douglas D. Boyd
Keyword(s):  
Rotor Blade ◽  
Unmanned Aircraft ◽  
Tip Clearance ◽  
Unmanned Aircraft Systems ◽  
Small Scale ◽  
Acoustic Measurements ◽  
Aircraft Systems ◽  
Brushless Motor ◽  
Close Proximity ◽  
Rotary Wing

In this study, acoustic measurements of a hover condition are taken on isolated rotor–airframe configurations representative of small-scale, rotary-wing unmanned aircraft systems (UAS). Each rotor–airframe configuration consists of two fixed-pitch blades powered by a brushless motor, with a simplified airframe geometry intended to represent a generic multicopter arm. In addition to acoustic measurements, computational fluid dynamics–based aeroacoustic predictions are implemented on a subset of the experimentally tested rotor–airframe configurations in an effort to better understand the noise content of the rotor–airframe systems. Favorable agreements are obtained between acoustic measurements and predictions, based on both time- and frequency-domain postprocessing techniques. Results indicate that close proximity of airframe surfaces results in the generation of considerable tonal acoustic content in the form of harmonics of the rotor blade passage frequency (BPF). Analysis of the acoustic prediction data shows that the presence of the airframe surfaces can generate noise levels either comparable to or greater than the rotor blade surfaces under certain rotor tip clearance conditions. Analysis of the on-surface Ffowcs Williams and Hawkings source terms provides insight as to the predicted physical noise-generating mechanisms on the rotor and airframe surfaces.

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