A taxonomy of UAS separation maneuvers and their automated execution

This paper proposes to create a taxonomy of separation conflicts between Unmanned Aerial Systems (UAS) and intruding aircrafts to facilitate its insertion in non-segregated airspace. The classification is created according to the relative speeds, angular geometry, initial intent, etc. A catalog of separation maneuvers that best fit each scenario is introduced and evaluated through a real-time simulation environment. This advisory mechanism will benefit both the UAS pilot and the ATCo in order to negotiate the best suited separation maneuver. Eventually, the same strategy can be employed as an autonomous separation system on-board a UAS that suffers a lost-link contingency, alleviating its negative impact in the airspace.Postprint (published version

Evaluation of UAS Separation Maneuvers and their Automated Execution

This project is focussed on the evaluation of the separation maneuvers done by the Unmanned Aerial Systems. For this evaluation the behaviour of variables such as speed of the UAS, heading changes done by the UAS and the different times to conflict are analysed. The evolution of the separation distance with these variables will be plotted. The project will focus on the oblique maneuver, for the forward case and the backward case. The maneuver is described and the ranges of angles that will define it are computed. This angles determine if the maneuver can be considered oblique or not, which means that if the conflict geometry is over the maximum or below the minimum angle the maneuver will not be considered as oblique. Finally an interpolation is done in order to determine which speeds, change of heading and time to conflict are necessary in order to execute the maneuver. Then the dependence with the minimum distance of every variable is explained. All these analysis are done using Matlab where different functions are used to compute all the distances, and this way its evolution with the other variables can be described

On the design of UAS horizontal separation maneuvers

This paper studies the separation maneuvers that an Unmanned Air System (UAS) may execute to avoid breaching the separation safety margins imposed in each type of airspace, namely 3 NM, 5 NM, and 10 NM. The UAS was assumed under the control of its Pilot in Command, with available information about its surrounding traffic through ADS-B or ADS-C, and most likely under the supervision of an ATCo. A number of UAS separation maneuvers have been identified that may guarantee the desired levels of separation if executed with the right parameters and enough anticipation. This paper focuses on identification of the most suitable maneuver for any separation conflict geometry and performance envelop. The conflict geometry is modeled to take into account the speed of both vehicles (the UAS and the intruder), the conflict angle, the turning limitations of the UAS, the reaction time of the pilot, and the communication latency.Postprint (published version

Architectural Design of a Safe Mission Manager for Unmanned Aircraft Systems

[EN] Civil Aviation Authorities are elaborating a new regulatory framework for the safe operation of Unmanned Aircraft Systems (UAS). Current proposals are based on the analysis of the specific risks of the operation as well as on the definition of some risk mitigation measures. In order to achieve the target level of safety, we propose increasing the level of automation by providing the on-board system with Automated Contingency Management functions. The aim of the resulting Safe Mission Manager System is to autonomously adapt to contingency events while still achieving mission objectives through the degradation of mission performance. In this paper, we discuss some of the architectural issues in designing this system. The resulting architecture makes a conceptual differentiation between event monitoring, decision-making on a policy for dealing with contingencies and the execution of the corresponding policy. We also discuss how to allocate the different Safe Mission Manager components to a partitioned, Integrated Modular Avionics architecture. Finally, determinism and predictability are key aspects in contingency management due to their overall impact on safety. For this reason, we model and verify the correctness of a contingency management policy using formal methods.This work was supported by the Spanish Regional Government "Generalitat Valenciana" under contract ACIF/2016/197.Usach Molina, H.; Vila Carbó, JA.; Torens, C.; Adolf, FM. (2018). Architectural Design of a Safe Mission Manager for Unmanned Aircraft Systems. Journal of Systems Architecture. 90:94-108. https://doi.org/10.1016/j.sysarc.2018.09.003S941089

The Generic Resolution Advisor and Conflict Evaluator (GRACE) for Unmanned Aircraft Detect-And-Avoid Systems

The paper describes the Generic Resolution Advisor and Conflict Evaluator (GRACE), a novel alerting and guidance algorithm that combines flexibility, robustness, and computational efficiency. GRACE is generic since it was designed without any assumptions regarding temporal or spatial scales, aircraft performance, or its sensor and communication systems. Therefore, GRACE was adopted as a core component of the Java Architecture for Detect-And-Avoid (DAA) Extensibility and Modeling, developed by NASA as a research and modeling tool for Unmanned Aerial Systems Integration in the National Airspace System (NAS). GRACE has been used in a number of real-time and fast-time experiments supporting evolving requirements of DAA research, including parametric studies, NAS-wide simulations, human-in-the-loop experiments, and live flight tests

The Generic Resolution Advisor and Conflict Evaluator (GRACE) for Detect-And-Avoid (DAA) Systems

The paper describes the Generic Resolution Advisor and Conflict Evaluator (GRACE), a novel alerting and guidance algorithm that combines flexibility, robustness, and computational efficiency. GRACE is "generic" in that it makes no assumptions regarding temporal or spatial scales, aircraft performance, or its sensor and communication systems. Accordingly, GRACE is well suited to research applications where alerting and guidance is a central feature and requirements are fluid involving a wide range of aviation technologies. GRACE has been used at NASA in a number of real-time and fast-time experiments supporting evolving requirements of DAA research, including parametric studies, NAS-wide simulations, human-in-the-loop experiments, and live flight tests

Maintaining separation between airliners and RPAS in non-segregated airspace

Best paper in track award. ATM Seminar Eurocontrol/FAA (2013-06-13)When an airliner and a Remotely Piloted Air System (RPAS) have conflicting courses that may compromise the minimum safety separation between them, how much in advance should the RPAS start the separation manoeuvre? Which is the optimal heading change that will guarantee the desired separation distance with a minimum reaction time? These same questions can be asked if it is the airliner that performs the separation manoeuvre. In this paper the time reaction margins for both aircraft are analysed assuming they are equipped with Automatic Dependent Surveillance (ADS) systems able to exchange aircraft intents. Due to their small cruise speeds, RPAS manoeuvres must be initiated well before the airliner ones. This leads to some safety buffer in case the RPAS cannot comply with the required change of trajectory or if it becomes suddenly unresponsive (due to an internal failure or because a lost-link situation). The paper also assesses the operational point of view by simplifying the reaction times and conflict geometries by grouping them in a small set of cases, regarding the severity of a loss of separation event.Award-winningPostprint (published version

Small UAS Detect and Avoid Requirements Necessary for Limited Beyond Visual Line of Sight (BVLOS) Operations

Potential small Unmanned Aircraft Systems (sUAS) beyond visual line of sight (BVLOS) operational scenarios/use cases and Detect And Avoid (DAA) approaches were collected through a number of industry wide data calls. Every 333 Exemption holder was solicited for this same information. Summary information from more than 5,000 exemption holders is documented, and the information received had varied level of detail but has given relevant experiential information to generalize use cases. A plan was developed and testing completed to assess Radio Line Of Sight (RLOS), a potential key limiting factors for safe BVLOS ops. Details of the equipment used, flight test area, test payload, and fixtures for testing at different altitudes is presented and the resulting comparison of a simplified mathematical model, an online modeling tool, and flight data are provided. An Operational Framework that defines the environment, conditions, constraints, and limitations under which the recommended requirements will enable sUAS operations BVLOS is presented. The framework includes strategies that can build upon Federal Aviation Administration (FAA) and industry actions that should result in an increase in BVLOS flights in the near term. Evaluating approaches to sUAS DAA was accomplished through five subtasks: literature review of pilot and ground observer see and avoid performance, survey of DAA criteria and recommended baseline performance, survey of existing/developing DAA technologies and performance, assessment of risks of selected DAA approaches, and flight testing. Pilot and ground observer see and avoid performance were evaluated through a literature review. Development of DAA criteria—the emphasis here being well clear— was accomplished through working with the Science And Research Panel (SARP) and through simulations of manned and unmanned aircraft interactions. Information regarding sUAS DAA approaches was collected through a literature review, requests for information, and direct interactions. These were analyzed through delineation of system type and definition of metrics and metric values. Risks associated with sUAS DAA systems were assessed by focusing on the Safety Risk Management (SRM) pillar of the SMS (Safety Management System) process. This effort (1) identified hazards related to the operation of sUAS in BVLOS, (2) offered a preliminary risk assessment considering existing controls, and (3) recommended additional controls and mitigations to further reduce risk to the lowest practical level. Finally, flight tests were conducted to collect preliminary data regarding well clear and DAA system hazards

Risk analysis of the future implementation of a safety management system for multiple RPAS based on first demonstration flights

The modern aeronautical scenario has welcomed the massive diffusion of new key elements, including the Remote Piloted Aircraft Systems (RPAS), initially used for military purposes only. The current decade has seen RPAS ready to become a new airspace user in a large variety of civilian applications. Although RPAS can currently only be flown into segregated airspaces, due to national and international Flight Aviation Authority (FAAs) constraints, they represent a remarkable potential growth in terms of development and economic investments for aviation. Full RPAS development will only happen when flight into non-segregated airspaces is authorized, as for manned civil and military aircraft. The preliminary requirement for disclosing the airspace to RPAS is the implementation of an ad hoc Safety Management System (SMS), as prescribed by ICAO, for every aeronautical operator. This issue arises in the context of the ongoing restructuring of airspaces management, according to SESAR-JU in Europe and NextGen in the USA (SESAR-JU has defined how RPAS research should be conducted in SESAR 2020, all in accordance with the 2015 European ATM Master Plan). This paper provides the basis to implement a risk model and general procedures/methodologies to investigate RPAS safety, according to the operational scenarios defined by EASA (European Aviation Safety Agency). The study is based on results achieved by multiple-RPAS experimental flights, performed within the RAID (RPAS-ATM Integration Demonstration) project

Unmanned Aircraft Systems in the Cyber Domain

Unmanned Aircraft Systems are an integral part of the US national critical infrastructure. The authors have endeavored to bring a breadth and quality of information to the reader that is unparalleled in the unclassified sphere. This textbook will fully immerse and engage the reader / student in the cyber-security considerations of this rapidly emerging technology that we know as unmanned aircraft systems (UAS). The first edition topics covered National Airspace (NAS) policy issues, information security (INFOSEC), UAS vulnerabilities in key systems (Sense and Avoid / SCADA), navigation and collision avoidance systems, stealth design, intelligence, surveillance and reconnaissance (ISR) platforms; weapons systems security; electronic warfare considerations; data-links, jamming, operational vulnerabilities and still-emerging political scenarios that affect US military / commercial decisions. This second edition discusses state-of-the-art technology issues facing US UAS designers. It focuses on counter unmanned aircraft systems (C-UAS) – especially research designed to mitigate and terminate threats by SWARMS. Topics include high-altitude platforms (HAPS) for wireless communications; C-UAS and large scale threats; acoustic countermeasures against SWARMS and building an Identify Friend or Foe (IFF) acoustic library; updates to the legal / regulatory landscape; UAS proliferation along the Chinese New Silk Road Sea / Land routes; and ethics in this new age of autonomous systems and artificial intelligence (AI).https://newprairiepress.org/ebooks/1027/thumbnail.jp