http://hdl.handle.net/2117/1077 2013-06-19T17:12:57Z http://hdl.handle.net/2117/19343 Title: On the design of a UAS flight plan monitoring and edition system Authors: Pastor Llorens, Enric; Santamaria Barnadas, Eduard; Royo Chic, Pablo; López Rubio, Juan; Barrado Muxí, Cristina Abstract: This paper addresses various aspects of the design and development of the pilot interface for the exploitation of highly advanced flight plan capabilities specifically designed for Unmanned Aerial Systems (UAS). This flight plan capabilities are built on top a flexible and reusable hardware/software architecture designed to facilitate the development of UAS-based applications. This flexibility is organized into an user-parameterizable UAS Service Abstraction Layer (USAL). The USAL defines a collection of standard services are their interrelations as a basic starting point for further development by UAS users. Previous research presented the advanced flying capabilities of a UAS as an extension of the Flight Control System (FCS) functionalities. Assuming a UAS with a FCS that ensures safe and stable maneuvers, we complement it with a highly capable flight plan management system. USAL flight plan is characterized by offering semantically much richer constructs than those present in most current UAS autopilots, which rely on simple lists of waypoints. This list of waypoints approach has several important limitations: it is difficult to specify complex trajectories and it does not support constructs such as conditional forks or iterations, small changes may imply having to deal with a considerable amount of waypoints and it provides no mechanism for adapting to mission time circumstances. To address these issues a new flight plan specification mechanism is proposed, that incorporates a leg concept extended to accommodate higher level constructs for specifying iterations and forks. Additional leg types, referred to as parametric leg, are also introduced. The trajectory defined by a parametric leg is automatically generated as a function of mission variables, enabling dynamic behavior and providing a very valuable means for adapting the flight to the mission evolution. Another level of adaption is provided by the conditions governing the decision-making in intersection le- - gs and the finalization of iterative legs. In this work we will focus on the development of the pilot interface for the exploitation of the introduced flight plan capabilities. The interface design requirements address an increase level of automated operation and support to react to unexpected requirements due to mission changes. Therefore, this interaction includes the available mechanisms to update the flight-plan according to UAS mission requirements, skip parts of it, react to operational contingencies, etc. 2013-05-17T14:02:55Z http://hdl.handle.net/2117/18909 Title: Effect of wind on operating cost based cruise speed reduction for delay absorption Authors: Delgado Muñoz, Luis; Prats Menéndez, Xavier Abstract: En route speed reduction can be used for air traffic flow management (ATFM), e.g., delaying aircraft while airborne or realizing metering at an arrival fix. In previous publications, the authors identified the flight conditions that maximize the airborne delay without incurring extra fuel consumption with respect to the nominal (not delayed) flight. In this paper, the effect of wind on this strategy is studied, and the sensitivity to wind forecast errors is also assessed. A case study done in Chicago O’Hare airport (ORD) is presented, showing that wind has a significant effect on the airborne delay that can be realized and that, in some cases, even tailwinds might lead to an increase in the maximum amount of airborne delay. The values of airborne delay are representative enough to suggest that this speed reduction technique might be useful in a real operational scenario. Moreover, the speed reduction strategy is more robust than nominal operations against fuel consumption in the presence of wind forecast uncertainties. 2013-04-22T08:53:55Z http://hdl.handle.net/2117/18501 Title: C3 in UAS as a means for secondary navigation Authors: Ramírez Alcántara, Jorge; Salazar Hernández, Dagoberto José; Prats Menéndez, Xavier; Barrado Muxí, Cristina Abstract: Unmanned Air Systems (UAS) navigate using Global Navigation Satellite Systems (GNSS), but GNSS vulnerability precludes its use as the only means of navigation and requires a secondary means of navigation. A differentiating characteristic of UAS is their periodic communications with the ground station. This paper analyses the adequacy of employing UAS Command, Control and Communications (C3) as a secondary means of navigation. With no additional infrastructure, an Extended Kalman Filter (EKF) is used to process C3 messages and to obtain the positions of the UAS. Navigation accuracy and integrity are calculated in a scenario with three UAS. The obtained results meet the International Civil Aviation Organization (ICAO) Performance-Based Navigation (PBN) requirements. 2013-03-22T13:25:04Z http://hdl.handle.net/2117/18494 Title: Simplified Femto-satellite Operations for Disaster Management Missions Authors: Tristancho Martínez, Joshua; Gutierrez Cabello, Jorge Luis Abstract: The reduction in size of satellites is reaching at the range of femto-satellites, i.e. satellites less than 100 grams in mass. One of the key points to achieve such a reduc tion is to simplify the design of the satellite, bu t also to simplify their mission operation. In the present work, a sim plified method for responsive femto-satellite opera tions is presented which is able to deal with the main types of disaster management tasks. Then, a mission is e asy to program using a few default functionalities in everyone of a cooperative satellite swarm giving a list of coor dinates. The protocol is able to update the list for adaptive mi ssions which are based on coordinates. This feature would allow an easy control for the first responders when they are in the field in the beginning of an emergency. The se satellites could send real-time pictures to the first responde rs agents, without the need of a complex ground sta tion infrastructure, until the help arrives 2013-03-22T12:53:17Z http://hdl.handle.net/2117/18419 Title: On the design of UAS horizontal separation maneuvers Authors: Pastor Llorens, Enric; Pérez Batlle, Marcos; Royo Chic, Pablo; Cuadrado Santolaria, Raúl; Barrado Muxí, Cristina; Prats Menéndez, Xavier Abstract: 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. 2013-03-19T16:55:26Z http://hdl.handle.net/2117/18418 Title: A taxonomy of UAS separation maneuvers and their automated execution Authors: Pérez Batlle, Marcos; Pastor Llorens, Enric; Royo Chic, Pablo; Prats Menéndez, Xavier; Barrado Muxí, Cristina Abstract: 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. 2013-03-19T16:41:40Z http://hdl.handle.net/2117/18403 Title: Spherical Rover for lunar and planetary exploration Authors: Gutierrez Cabello, Jorge Luis; Tristancho Martínez, Joshua Abstract: Historically, planetary and lunar rovers have been wheeled-driven. While this is usually seen as an advantage –due to the flight experience– in some cases, the unavoidable presence of gears and mobile parts can be a significant hazard to the mission. The abrasive lunar regolith has been the origin of substantial problems with the Apollo rovers. Here we propose a completely different scheme: a spherical rover in which all the moving parts are protected from the environment by an external spherical shell 2013-03-19T13:28:17Z http://hdl.handle.net/2117/18013 Title: Helicopter-based wildfire monitoring system software architecture Authors: Pastor Llorens, Enric; Solé Simó, Marc; López, Juan; Royo Chic, Pablo; Barrado Muxí, Cristina Abstract: This work introduces a flexible and reusable architecture designed to facilitate the development of remote sensing applications. Based on it, we are developing a helicopter system, called Red-Eye, devoted to the detection, control and analysis of wild land forest fires in the Mediterranean area. The design of the proposed system is composed of five main components. Each component will work collaboratively to constitute a platform of high added value. The general architecture designed for wildfire monitoring is being tailored for two relevant objectives within the particular Mediterranean scenario: tactical day/night fire front evolution, and post-fire hot-spot detection. The generalized integration of monitoring vehicles with the operation of other aerial resources (attack helicopter and airplanes) is an unsolved problem, both technically and methodologically. However, the operation of a monitoring helicopter during certain very well identified phases of the extinction process in highly plausible. High-level strategic monitoring is possible because no-conflicts will appear due to different flight levels; however, low-level tactical monitoring is a source of potentially dangerous in-flight traffic conflicts. In addition to monitoring the fire front evolution, detection of remaining post-fire hot-spots located at the perimeter of fire is the main application that has been foreseen. Just after a fire front is contained or even during the days following the fire extinction, the monitoring tasks have to be maintained because of the danger of fire reactivation. The cost of monitoring with ground teams or aerial means it is very expensive and consumes resources needed in other fronts or possibly concurrent fires. However, a helicopter equipped with thermal cameras, can flight over the area and generate a map of hot spots with higher precision at a smaller cost. It is crucial in this application that the hot spots are reported immediately to avoid having ground brigades wai- - ting for data for too long. Also, it is important to feedback the information in such a way it can be effectively consumed, not forcing ground brigades to walk around the forest without a clear operational scheme. Based on a Service Oriented Architecture (SOA) a heliborne hot-spot detection system is being developed. This paper describes the global architecture of the system, including the air segment, the ground control segment, and the interface with the squads operating on the fire area, etc. We also demonstrate how the available pre-defined modules in the SOA architecture have been reused to design this particular application, the additional subsystems required to implement specific hot-spot mission requirements, and the overall system / end-user interface. Description: Software architecture 2013-02-27T18:59:37Z http://hdl.handle.net/2117/16558 Title: An environmental assessment of air traffic speed constraints in the departure phase of flight: A case study at Gothenburg Landvetter Airport, Sweden Authors: Mitchell, Deborah; Ekstrand, Henrik; Prats Menéndez, Xavier; Grönstedt, Tomas 2012-09-25T10:18:25Z http://hdl.handle.net/2117/16549 Title: UAS architecture for forest fire remote sensing Authors: Royo Chic, Pablo; Pastor Llorens, Enric; Solé, M.; Lema Rosas, Juan Manuel; López Rubio, Juan; Barrado Muxí, Cristina Abstract: This paper presents the hardware/software architecture of the Sky-Eye UAS prototype. In particular it details the hardware of the prototype, its operational concept and the software avionics architecture. The software architecture is named UAS Service Abstraction Layer (USAL) and consists on the set of standard services required for most UAS missions. The USAL is a distributed architecture which follows the publish / subscribe communication paradigm, allowing fast development of new functionalities. We describe the USAL services required to properly manage the remote sensing mission of hot spot detection. This includes the sensor management, data storage, communications, image processing, flight plan management and mission management. 2012-09-20T18:19:19Z http://hdl.handle.net/2117/16460 Title: ATFM airborne delays without extra fuel consumption in wind conditions Authors: Delgado Muñoz, Luis; Prats Menéndez, Xavier Abstract: Air Traffic Flow Management (ATFM) regulations, such as ground holdings, are often canceled before their initially planned ending time. The ground delays impact on the cost of recovering part of the delay if the regulation is canceled, as aircraft are still at the origin airport. In previous publications, the authors have suggested a speed reduction strategy to split the assigned ATFM delay between ground delay and airborne delay. By flying at the the minimum speed that gives the same fuel consumption as initially planned, the airline can maximize the airborne delay without any extra fuel consumption. In this paper, the effect of wind on the amount of airborne delay is assessed and a case study of Chicago O’hare airport is presented. Results show that wind has a great effect on the airborne delay that can be achieved and that, in some cases, even tail winds might lead to an increase of airborne delay 2012-09-10T11:29:44Z http://hdl.handle.net/2117/16458 Title: Requirements, issues, and challenges for sense and avoid in Unmanned Aircraft Systems Authors: Prats Menéndez, Xavier; Delgado Muñoz, Luis; Ramírez Alcántara, Jorge; Royo Chic, Pablo; Pastor Llorens, Enric Abstract: The sense and avoid capability is one of the greatest challenges that has to be addressed to safely integrate unmanned aircraft systems into civil and nonsegregated airspace. This paper gives a review of existing regulations, recommended practices, and standards in sense and avoid for unmanned aircraft systems. Gaps and issues are identified, as are the different factors that are likely to affect actual sense and avoid requirements. It is found that the operational environment (flight altitude, meteorological conditions, and class of airspace) plays an important role when determining the type of flying hazards that the unmanned aircraft system might encounter. In addition, the automation level and the data-link architecture of the unmanned aircraft system are key factors that will definitely determine the sense and avoid system requirements. Tactical unmanned aircraft, performing similar missions to general aviation, are found to be the most challenging systems from an sense and avoid point of view, and further research and development efforts are still needed before their seamless integration into nonsegregated airspace. 2012-09-10T10:50:11Z http://hdl.handle.net/2117/16282 Title: Flight plan specification and management for unmanned aircraft systems Authors: Santamaria Barnadas, Eduard; Pastor Llorens, Enric; Barrado Muxí, Cristina; Prats Menéndez, Xavier; Royo Chic, Pablo; Pérez Batlle, Marcos Abstract: This paper presents a new concept for specifying Unmanned Aircraft Systems (UAS) flight operations that aims at improving the waypoint based approach, found in most autopilot systems, by providing higher level fligh plan specification primitives. The proposed method borrows the leg and path terminator concepts used in Area Navigation1 (RNAV). Several RNAV leg types are adopted and extended with new ones for a better adaptation to UAS requirements. Extensions include the addition of control constructs that enable repetitive and conditional behavior, and also parametric legs that can be used to generate complex paths from a reduced number of parameters. The paper also covers the design and implementation of a software component that manages execution of the flight plan. To take advantage of current off-the-shelf flight control systems the constructs included in the flight plan are translated to waypoint navigation commands. In this way, the advanced capabilities provided by the flight plan specification language are implemented as a new layer on top of existing technologies. The benefits and the feasibility of the proposed approach for UAS flight plan management are demonstrated by means of a simulated mission that performs the flight inspection of Radio Navigation Aids. 2012-07-17T17:41:52Z http://hdl.handle.net/2117/16017 Title: Design of a Supersonic Wind Tunnel Authors: Torunogullari, Altay; Schneider, Maxime; Pal, Itsvan; Tristancho Martínez, Joshua Abstract: This study was a preliminary work of how to implement a rocket with sensors in order to get information about the flight. 2012-06-11T15:12:07Z http://hdl.handle.net/2117/15975 Title: Evaluation of separation strategies for unmanned aerial sytems Authors: Pérez Batlle, Marcos; Pastor Llorens, Enric; Prats Menéndez, Xavier Abstract: This paper analyzes loss of separation scenarios when an Unmanned Aircraft (UA) enters in conflict with a much faster airplane flying at the same altitude. Separation distances are analyzed in terms of minimum heading changes and reaction times. Results show that maneuvers need to be performed well in advance if the (low-speed) UA is the aircraft that changes its heading. In some cases the time in which the UA and the intruder are in conflict could be too long, and may even involve multiple airliners flying over the same airway. Given that standard separation strategies may have a negative impact on the UA mission, in this paper a set of pre-planned separation maneuvers are proposed. These maneuvers aim to improve the situational awareness of both air traffic controller and UA pilotin- command, but also to disrupt as less as possible the mission performed by the UA and to minimize the uncertainty in the reactions the UA may adopt autonomously if the link with the ground station is lost. Some preliminary real-time simulations are shown, using a UA ground station simulator linked to a air traffic control simulator. 2012-06-07T10:12:58Z