Trajectory optimisation for avionics-based GNSS integrity augmentation system

In this paper, trajectory optimisation algorithms developed specifically for the Global Navigation satellite System (GNSS) Avionics-Based Integrity Augmentation (ABIA) system are presented. The ABIA system is designed to increase the levels of integrity and accuracy (as well as continuity in multi-sensor data fusion architectures) of GNSS in a variety of mission- and safetycritical aviation applications. The trajectory optimisation algorithms can be employed both for flight planning as well as realtime optimisation of manned and unmanned aircraft for all flight phases. Three and six Degrees-of-Freedom (3-DoF/6-DoF) aircraft dynamics models are adopted to generate a number of feasible flight trajectories that also satisfy the GNSS constraints. A detailed simulation case study is presented to evaluate the performance of trajectory optimisation algorithms for GNSS integrity augmentation using an AIRBUS A320 3-DoF aircraft dynamics model. Results confirm that the employed trajectory optimisation algorithms are capable of supporting high-integrity tasks when GNSS is used as the primary source of navigation data

LIDAR Obstacle Warning and Avoidance System for Unmanned Aircraft

The availability of powerful eye-safe laser sources and the recent advancements in electro-optical and mechanical beam-steering components have allowed laser-based Light Detection and Ranging (LIDAR) to become a promising technology for obstacle warning and avoidance in a variety of manned and unmanned aircraft applications. LIDAR outstanding angular resolution and accuracy characteristics are coupled to its good detection performance in a wide range of incidence angles and weather conditions, providing an ideal obstacle avoidance solution, which is especially attractive in military low-level flying platforms such as helicopters and small-size Unmanned Aircraft (UA). In this paper we discuss the integration of the Laser Obstacle Avoidance "Marconi" (LOAM) system on candidate UA platforms. The original LOAM system design and the performed helicopter test activities are summarised, including a brief description of the system architecture and sensor characteristics, together with the system performance models and data processing algorithms for obstacle detection and classification. The paper presents the dynamic modelling and the avoidance trajectory generation algorithm for UA applications. A description of the future planned flight test activities is also included

Machine Learning and Cognitive Ergonomics in Air Traffic Management: Recent Developments and Considerations for Certification

Resurgent interest in artificial intelligence (AI) techniques focused research attention on their application in aviation systems including air traffic management (ATM), air traffic flow management (ATFM), and unmanned aerial systems traffic management (UTM). By considering a novel cognitive human&ndash machine interface (HMI), configured via machine learning, we examined the requirements for such techniques to be deployed operationally in an ATM system, exploring aspects of vendor verification, regulatory certification, and end-user acceptance. We conclude that research into related fields such as explainable AI (XAI) and computer-aided verification needs to keep pace with applied AI research in order to close the research gaps that could hinder operational deployment. Furthermore, we postulate that the increasing levels of automation and autonomy introduced by AI techniques will eventually subject ATM systems to certification requirements, and we propose a means by which ground-based ATM systems can be accommodated into the existing certification framework for aviation systems. Document type: Articl

Plasma wind tunnel characterization of plasma-sprayed UHTC coatings

Ceramic coatings are widely used as thermal barrier or as oxidation barrier, in many industrial applications. The use of UHTC is mandatory when dealing with hypersonic vehicles characterized by high thermal flux in oxidizing environment. Since 2000, in the framework of the national aerospace research program (PRORA-SHS) and within various other National and European programs, CIRA has studied, developed, and tested monolithic UHTCs and UHTC coatings on different high temperature structural materials. Small winglets and nose made in UHTC (EXPERT and SHARK project) or UHTC coated (SCRAMSPACE project) were designed, manufactured and installed on rockets or re-entry vehicles for in-flight qualification. Unfortunately, only the SHARK nose tip experienced the flighty environment. Please click Additional Files below to see the full abstract

Manual de Cenários de Risco e Danos de Tsunami

O manual de cenários de tsunami é o resultado de um trabalho intenso realizado no âmbito do projecto europeu FP6 SCHEMA, co-financiado num período de 39 meses, de 2007 a 2010, num consórcio de 11 parceiros liderado pela Geosciences Consultants (Paris). O manual é um dos produtos do projecto, concebido para ilustrar os conceitos básicos e métodos criados e aplicados no projecto para a produção de cenários de tsunami, tendo em vista a disponibilização de ferramentas de avaliação de riscos de tsunami e danos potenciais. Um dos objectivos principais foi a elaboração de uma metodologia geral que pudesse ser facilmente adaptada às necessidades dos utilizadores finais, principalmente dos gestores públicos responsáveis pelo planeamento de estratégias de desenvolvimento e protecção costeiras, bem como das pessoas e organizações envolvidas na gestão de desastres e políticas de mitigação. Por estas razões, a metodologia do SCHEMA foi aplicada em cinco locais (Rabat, Marrocos; Setúbal, Portugal; Mandelieu, França; Catania, Itália; Balchik, Bulgária) com diferenças significativas entre si, tendo sido testada com o envolvimento activo dos utilizadores finais, assegurando a disponibilização de ferramentas úteis e práticas com flexibilidade suficiente para cobrir as necessidades locais. O manual define, em primeiro lugar, o significado de “cenário de risco de tsunami” e “cenário de danos devidos a tsunami”, bem como o conceito de “pior cenário credível”. Este último conceito é um ponto-chave do manual, uma vez que a escolha do consórcio SCHEMA consistiu na adopção da abordagem de pior cenário credível em detrimento de cenários elaborados por análise probabilística, por se crer não existirem conhecimentos e dados actuais suficientes para avaliar fielmente a probabilidade de retorno de tsunamis e consequentemente a criação de cenários probabilísticos correspondentes. A metodologia, descrita de forma sucinta no capítulo 3, consiste em três fases principais, por sua vez abrangendo outras sub-fases ou passos: 1 – Elaboração de um conjunto de cenários de risco de tsunami para cada local em estudo (também referido como zona-alvo), agregando-se num único cenário combinado; 2 – Análise da vulnerabilidade de elementos expostos, baseada em observações recolhidas em pesquisas de campo e na interpretação de imagens de satélite; 3 – Desenvolvimento de cenários de danos devidos a tsunami. A fase 1 é descrita em detalhe no capítulo 4, ao passo que as fases 2 e 3 são ilustradas no capítulo 5. Este manual tem como propósito realçar a abordagem SCHEMA aos cenários de tsunami e é deliberadamente pequeno e sintético. Todos os detalhes dos métodos e da sua aplicação podem ser obtidos nos vários e extensos documentos produzidos pelo consórcio no período de duração do projecto. Neste documento são apenas referidos os conceitos principais, ilustrados por exemplos recolhidos a partir do trabalho realizado pelos parceiros do consórcio. O capítulo final do manual aponta para o futuro, principalmente através do foco nos desafios futuros e a forma como a metodologia poderá ser melhorada para lidar com esses desafios. Neste contexto, o tema principal é o multi-risco ou, noutras palavras, a forma como os cenários podem ser criados para cobrir não apenas tsunamis mas também outros fenómenos de risco. O desafio está lançado, existindo actualmente o reconhecimento de que esta problemática é séria e antiga e que não há ainda certezas sobre a forma geral de lidar com o problema. Esperamos que sejam concretizados desenvolvimentos importantes nos próximos anos.JRC.DG.G.7-Traceability and vulnerability assessmen

Handbook on tsunami hazards and damage scenarios

The handbook is one of the products of the SCHEMA project (FP 6 Space priority) and has been conceived to illustrate the basic concepts and methods that have been elaborated and applied in the project to produce tsunami scenarios in view of providing tools to assess hazard and potential damage resulting from tsunamis. One of the main objectives was the elaboration of a general methodology that can be used in all possible cases and that can be adapted easily to the needs of the end users, i.e. chiefly the public administrators responsible for planning of the coastal zone development and protection strategies as well as people and organisations involved in disasters management and mitigation policies. It is for these reasons, that the SCHEMA methodology has been applied to five test sites (Rabat, Morocco; Setúbal, Portugal; Mandelieu, France; Catania, Italy; Balchik, Bulgaria) that differ very much from one another, so proving that it is suitable for a quite large variety of cases, and that it has been tested with the active involvement of the end users, so ensuring that it will provide practical and useful tools and it is flexible enough to cover local needs.JRC.DG.G.7-Traceability and vulnerability assessmen

Experimental flight testing of night vision imaging systems in military fighter aircraft

This paper describes the research and experimental flight test activities conducted by the Italian Air Force Official Test Centre (RSV), in collaboration with Alenia Aermacchi and Cranfield University, in order to confer night vision imaging systems (NVIS) capability to the Italian TORNADO Interdiction and Strike and Electronic Combat and Reconnaissance aircraft. The activities included design, development, test, and evaluation activities, including night vision goggle (NVG) integration, cockpit instruments, and external lighting modifications, as well as various ground test sessions and a total of 18 flight test sorties. RSV and Litton Precision Products were responsible for coordinating and conducting the installation of the internal and external lights. Particularly, an iterative process was established allowing in-site rapid correction of the major deficiencies encountered during the ground and flight test sessions. Both single-ship (day/night) and formation (night) flights were performed, with testing activities shared among the test crews involved, allowing for a redundant examination of the various test items by all participants. An innovative test matrix was developed and implemented by RSV for assessing the operational suitability and effectiveness of the various modifications implemented. Also important was the definition of test criteria for Pilot and Weapon Systems Officer workload assessment during the accomplishment of various operational tasks during NVG missions. Furthermore, the specific technical and operational elements required for evaluating the modified helmets were identified, allowing an exhaustive comparative evaluation of the two proposed solutions (i.e., HGU-55P and HGU-55G modified helmets). The initial compatibility problems encountered were progressively mitigated by incorporating modifications in both front and rear cockpits at various stages of the test campaign. This process allowed considerable enhancement of the TORNADO NVIS configuration, giving good medium- to high-level NVG operational capability to the aircraft. Further developments also include the internal/external lighting for the Italian TORNADO “Mid-Life Update” and other programs such as AMX aircraft internal/external light modification/testing and the activities addressing low-altitude NVG operations with fast jets (e.g., TORNADO, AMX, MB-339CD), with a major issue being the safe ejection of aircrew with NVG and NVG modified helmets. Two options have been identified for solving this problem, namely, the modification of the current Gentex HGU-55 helmets and the design of a new helmet incorporating a reliable NVG connection/disconnection device (i.e., a mechanical system fully integrated in the helmet frame) with embedded automatic disconnection capability in case of ejection. Other relevant issues to be accounted for in these new developments are the helmet dimensions and weight, the NVG usable field of view as a function of eye-relief distance, and the helmet's center of gravity (moment arms) with and without NVG (effect on aircrew fatigue during training and real operational missions

Manuale per Scenari di Pericolosità e di Danno in Caso di Tsunami

Il manuale sugli scenari di maremoto è il risultato del lavoro svolto nell’ambito del progetto SCHEMA (finanziato dall’Unione Europea, in un periodo di 39 mesi dal 2007 al 2010) da un Consorzio di 11 partner, guidato da Geosciences Consultants. Il manuale è uno dei prodotti del progetto ed ha lo scopo di illustrare i concetti ed i metodi di base che sono stati elaborati ed applicati nel corso del progetto per produrre scenari utili per la stima della pericolosità e del danno derivante dall’impatto dei maremoti. Viene proposto un metodo generale che può essere facilmente adattato alle diverse necessità degli utilizzatori finali, che sono principalmente le pubbliche amministrazioni responsabili della pianificazione dello sviluppo delle zone costiere e dell’elaborazione delle strategie di protezione dai rischi naturali, così come le persone e le organizzazioni coinvolte nella gestione dei disastri e in politiche di mitigazione. La metodologia adottata nel progetto SCHEMA è stata applicata a cinque aree campione (Rabat, Marocco; Setúbal, Portogallo; Mandelieu, Francia; Catania, Italia; Balchik, Bulgaria) molto diverse l’una dall’altra, a riprova che essa è adattabile a una grande varietà di casi. Essa è stata testata con il coinvolgimento attivo degli utilizzatori finali, il che assicura che si tratta di uno strumento utile, pratico e sufficientemente flessibile da coprire le necessità delle singole località. Nella prima parte del manuale si definiscono i concetti di “Scenario di pericolosità” e di “Scenario di danno” in caso di maremoto, così come il concetto di “Peggior scenario credibile”. Quest’ultimo rappresenta il punto chiave del manuale, poiché il consorzio di SCHEMA ha scelto di adottare l’approccio del peggior scenario credibile piuttosto che quello basato su scenari risultanti da analisi probabilistiche. Il motivo della scelta è che si ritiene che non ci siano né conoscenze né dati a sufficienza per stimare la probabilità di tempi di ritorno dei maremoti, e quindi per ricavare i corrispondenti scenari. Il metodo è brevemente illustrato nel capitolo 3, nel quale si spiega che è costituito da tre fasi principali, ognuna delle quali suddivisibile in ulteriori sotto-fasi: 1) l’elaborazione di un certo numero di scenari di pericolosità per ogni area campione, che poi vengono combinati in un singolo scenario aggregato; 2) analisi di vulnerabilità degli elementi esposti al maremoto basata su osservazioni (derivanti da campagne di misura e da interpretazione di immagini satellitari); 3) sviluppo dello scenario di danno da maremoto. La fase 1 è descritta in moto dettagliato nel capitolo 4, mentre le fasi 2 e 3 sono illustrate nel successivo capitolo 5. Il manuale ha lo scopo di evidenziare i punti fondamentali della metodologia adottata nel progetto SCHEMA per gli scenari di maremoto, ed è perciò volutamente sintetico. Ogni dettaglio sui metodi e sulle loro applicazioni può essere trovato nei molti e dettagliati documenti (deliverables) prodotti dal consorzio durante tutto il progetto. Qui vengono illustrati solo i concetti fondamentali attraverso un numero di esempi presi dal lavoro svolto dai partner del consorzio. Il capitolo finale del manuale guarda al futuro, con enfasi sulle prossime sfide e su come la metodologia possa essere migliorata per affrontarle. In questo contesto l’argomento principale è la multi-pericolosità o, in altre parole, come gli scenari possano essere costruiti per considerare non solo i maremoti ma anche altri fenomeni pericolosi. La sfida rimane aperta nel senso che è ormai diffusa la consapevolezza i) che questo sia un serio problema e ii) che, allo stesso tempo, non ci siano metodi generali per affrontarlo.JRC.DG.G.7-Traceability and vulnerability assessmen

A new computational technique for the generation of optimised aircraft trajectories

A new computational technique based on Pseudospectral Discretisation (PSD) and adaptive bisection ε-constraint methods is proposed to solve multi-objective aircraft trajectory optimisation problems formulated as nonlinear optimal control problems. This technique is applicable to a variety of next-generation avionics and Air Traffic Management (ATM) Decision Support Systems (DSS) for strategic and tactical replanning operations. These include the future Flight Management Systems (FMS) and the 4-Dimensional Trajectory (4DT) planning and intent negotiation/validation tools envisaged by SESAR and NextGen for a global implementation. In particular, after describing the PSD method, the adaptive bisection ε-constraint method is presented to allow an efficient solution of problems in which two or multiple performance indices are to be minimized simultaneously. Initial simulation case studies were performed adopting suitable aircraft dynamics models and addressing a classical vertical trajectory optimisation problem with two objectives simultaneously. Subsequently, a more advanced 4DT simulation case study is presented with a focus on representative ATM optimisation objectives in the Terminal Manoeuvring Area (TMA). The simulation results are analysed in-depth and corroborated by flight performance analysis, supporting the validity of the proposed computational techniques.peer-reviewe

Plasma wind tunnel testing of UHTC coated components for hypersonic applications

Please click Additional Files below to see the full abstract