Aeronautical Research Papers - Academia.edu (original) (raw)

Efforts are being taken to make space missions more affordable. Reusable Launch Vehicle (RLV) is one such innovation aimed to reduce the manufacturing costs drastically. Developments are being made to make improvements on the already existing landers and also to make the full rocket reusable. This article examines the present state of the technology for reusable launch vehicles. and also aims to provide an enhancement to the already existing landing legs used on reusable launch vehicles (RLV) which can help the rocket land on uneven surfaces. This landing mechanism employs honeycomb shock absorber to absorb the energy during landing. The main purposefulness of this idea is to avoid the moment which topples the rocket during landing on uneven terrain. The paper also provides results from various analyses conducted to support the proposed idea.

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- Aerospace Engineering, Space Science, Defence, Aeronautical
- by Rodolfo Bontempo and +1
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- Aerospace Engineering, Fluid Mechanics, Aeronautical Engineering, Aerodynamics

Review of Fluid Mechanics: Importance of Aerodynamics, Fundamental aerodynamics variables and dimensional analysis (statement of Buckingham theorem) leading to force & moment coefficient and dimensionless similarity parameters such as Reynolds number, Mach number, incompressible flow, compressible flow and Mach number-Continuity & momentum equations in differential form. Euler equation, viscosity, Navier –Stokes equation, Reynolds number.

- by SHIVA PRASAD U
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- Fluid Mechanics, Aerodynamics, Aeronautics, Aeronautical

basic information about Jet-lag that should to know as a cabin crew or passenger...

- by ISSAM SAGHOURI EL IDRISSI
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- Traveling, Airplanes, Aeronautical, Pilot study
- by Muhammad C
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- Communication, Aviation, Aviation Safety, Aeronautical
- by Anestis Kalfas
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- Engineering, Aerospace Engineering, Thermodynamics, Modeling

Modern Compressible Flow with historical perspective second edition John D. Anderson, jr.

- by Görkem Ertural
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- Aerodynamics, Aerospace, Fluid Dynamics, Inviscid Flows

This paper presents the concept of Cognitive Human-Machine Interfaces and Interactions (CHMI2) for Unmanned Aircraft Systems (UAS) Ground Control Stations (GCS). CHMI2 is a new approach to aviation human factors engineering that introduces adaptive functionalities in the design of operators' command, control and display functions. A CHMI 2 system assesses human cognitive states based on measurement of key psycho-physiological observables. The cognitive states are used to predict and enhance operator performance in the accomplishment of aviation tasks, with the objective of improving the efficiency and effectiveness of the overall human-machine teaming. The CHMI 2 system in this paper employs a four-layer architecture comprising sensing, extraction, classification and adaptation functionalities. An overview of each layer is provided along with the layer's metrics, algorithms and functions. Two relevant case studies are presented to illustrate the interactions between the different layers, and the conceptual design of the associated display formats is described. The results indicate that specific eye tracking variables provide discrimination between different modes of control. Furthermore, results indicate that higher levels of automation are preferred in Separation Assurance and Collision Avoidance (SA&CA) scenarios involving low-detectability obstacles. It is anticipated that the use of CHMI 2 systems in UAS SA&CA applications will reduce reaction time and enhance operational effectiveness in responding to collision avoidance/loss of separation events, as well as improving the overall safety of operations.

- by Roberto Sabatini and +1
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- Aerospace Engineering, Cognitive Psychology, Cognitive Science, Human Computer Interaction

The integration of advanced distributed propulsion (DP) systems within various aircraft configurations holds the potential to greatly increase aircraft performance, particularly in terms of fuel efficiency, reduction of harmful emissions and reduction of take-off field length requirements. This has been enabled by modern analysis tools, materials technology and control systems which take advantage of the positive interactions between the propulsive configuration and the aerodynamics of the aircraft. In particular, synergies are maximized when the propulsion system uses distributed nozzles, crossflow fans and multiple distributed fans. Recent advances in electric propulsion have encouraged the hybridization of propulsive systems, with airliners having multiple electric fans powered by one or two gas turbine engines. Furthermore, due to recent advances in airframe integration solutions, the propulsive element can become an integral part of the control and stability augmentation capabilities of the aircraft. Thereby, the digital control of advanced DP systems is crucial for the purpose of thrust modulation and intelligent management of engine resources and health. This not only aids in mission optimization but also support the case for airworthiness certification of novel aircraft configurations integrating advanced DP systems. This paper presents a critical review of the existing literature on the subject of DP, identifying the benefits and drawbacks of this technology as well as its proposed practical applications. The review also discusses contemporary advances in hybrid electric technology, aeroelasticity research and the fundamental design steps to integrate advanced DP systems in fixed-wing aircraft. Additionally, an evolutionary outlook is presented on digital control of DP systems with a focus on advancing the techniques for mission optimization and engine health management for enhanced safety and sustainability. Based on the proposed design principles and digital control methodology, conclusions are drawn about the suitability of advanced DP for various applications and recommendations are made for future research and development.

Today, in 2021, a new generation of artists, activists, students, teachers, scientists, engineers, global humanity are engaging & evolving the internet. All part of the first GLOBAL polity, consciousness which emerged in 2020. Post-biosphere Collapse, Post-Anthropocene, Mid-Economic and Social Collapse. Most of the internet content from the last three decades is no longer extent, including my (Spaceplane, Aerospace, and Other) work. Viz. most webpages, all of Yahoo Groups, Google Groups, Google+, and Notes and everything which has been disappeared from Facebook. So today, with the help of the Wayback Machine, I downloaded and made a quick PDF of one of my X49 Stratoliner Spaceplane designs from two decades ago, which were once publicly available online. Hopefully, our rapidly-evolving (AI-assisted) humanity will make all of our internet history, and science, available and transparent in the coming years. And a thousand- and million-fold greater Global Humanity and Consciousness soon empower us. All Our Sacred Relations, our Health and Sanity, Returning ...

The modification of aerofoils with structural morphing in order to enhance aerodynamic efficiency is an active field of research. The required forced and induced displacements are, usually, out the current developments on shape memory alloys, piezoelectric actuators or multi-stable structures for commercial transport aircraft applications. This work aims to present studies for obtaining an optimum rudder structure which morphs to a pre-defined curvature that can sustain aerodynamic and internal loads in a critical certification load case for a commercial transport aircraft. It also includes the feasibility of a morphing rudder based on a zero Poisson skeleton, or close to a zero Poisson ratio panel geometrical configuration that has no transverse deformation when perpendicularly loaded and which is produced with an additive layer manufacturing process.

- by Miguel Castillo
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- Engineering, Aeronautical
- by la bv
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- Aeronautics and aerospace, Aeronautical

In recent years Air Traffic Flow Management (ATFM) has become pertinent even in regions without sustained overload conditions caused by dense traffic operations. Increasing traffic volumes in the face of constrained resources has created peak congestion at specific locations and times in many areas of the world. Increased environmental awareness and economic drivers have combined to create a resurgent interest in ATFM as evidenced by a spate of recent ATFM conferences and workshops mediated by official bodies such as ICAO, IATA, CANSO the FAA and Eurocontrol. Significant ATFM acquisitions in the last 5 years include South Africa, Australia and India. Singapore, Thailand and Korea are all expected to procure ATFM systems within a year while China is expected to develop a bespoke system. Asia-Pacific nations are particularly pro-active given the traffic growth projections for the region (by 2050 half of all air traffic will be to, from or within the Asia-Pacific region). National authorities now have access to recently published international standards to guide the development of national and regional operational concepts for ATFM, geared to Communications, Navigation, Surveillance/Air Traffic Management and Avionics (CNS+A) evolutions. This paper critically reviews the field to determine which ATFM research and development efforts hold the best promise for practical technological implementations, offering clear benefits both in terms of enhanced safety and efficiency in times of growing air traffic. An evolutionary approach is adopted starting from an ontology of current ATFM techniques and proceeding to identify the technological and regulatory evolutions required in the future CNS+A context, as the aviation industry moves forward with a clearer understanding of emerging operational needs, the geo-political realities of regional collaboration and the impending needs of global harmonization.

- by Trevor Kistan and +3
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- Aerospace Engineering, Decision Making, Operations Management, Operations Research
- by venses franklin
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- Aeronautical

Interactive Aerospace Engineering and Design

- by HAMZA ALI
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- Aerospace Engineering, Aeronautical Engineering, Aerospace, Aeronautical

Abstract
Due to technological progress in the field of aviation and navigational satellite systems, automated remote control systems and the success role of an Unmanned Aircraft System (AUS) in military and
security applications, as well as their use in some civilian uses, such as fighting forest fires, meteorological observations, scientific research, environmental protection, and other uses.
Despite the attention of the International Maritime Organization (IMO) by maritime safety to reduce maritime accidents through modern technologies and the improvement of maritime conventions, which tightened its control over ship ՛s operators But she could not prevent maritime accidents that turn into disasters due to enormous loss of life especially mass passenger ship and illegal immigration accidents.
The most important success of the (SAR) operations is time factors to face drowning and hypothermia throw quickly to respond by receiving distress signals, detecting distress position, collecting accident data to assess the situation, planning and response for (SAR) operations by rescue units.
This research paper discusses the importance of the use of (AUS - SAR) operations since receiving a signal of distress and collect data of the accident. Then assess the situation and support the planning, handling monitoring and tracking (SAR) operations. (AUS - SAR) can light the sea at night and drop rescue equipment for the survivors until the arrival of rescue units. it can be used to monitor the body temperature of survivors at sea by thermal cameras. To achieve the main aims of the research to increase the efficiency of search and rescue operations and minimize the loss of life.
KEYWORDS
Search and rescue (SAR) operations - IMO - ICAO - Unmanned Aircraft System (AUS) – Classification OF UAV - Mass Rescue Operations - Mystery disaster & Investigation - MOB accident

Progress in spaceflight research has led to the introduction of various manned and unmanned reusable space vehicle concepts, opening up uncharted opportunities for the newborn space transport industry. For future space transport operations to be technically and commercially viable, it is critical that an acceptable level of safety is provided, requiring the development of novel mission planning and decision support tools that utilize advanced Communication, Navigation and Surveillance (CNS) technologies, and allowing a seamless integration of space operations in the current Air Traffic Management (ATM) network. A review of emerging platform operational concepts is conducted, highlighting both the challenges and the opportunities brought in by the integration with conventional atmospheric air transport. Common launch and re-entry planning methodologies are then discussed, where the physical and computational limitations of these approaches are identified and applicability to future commercial space transport operations is assessed. Attention is then turned to the on-orbit phase, where the unique hazards of the space environment are examined, followed by an overview to the necessary elements required for space object de-confliction and collision avoidance modelling. The regulatory framework evolutions required for spacecraft operations are then discussed, with a focus on space debris mitigation strategies and operational risk assessment. Within the atmospheric domain, possible extensions and alternatives to the conventional airspace segregation approaches are identified including promising Air Traffic Flow Management (ATFM) techniques to facilitate the integration of new-entrant platforms. Lastly, recent modelling approaches to meet on-orbit risk criteria are discussed and evolutionary requirements to improve current operational procedures are identified. These insights will inform future research on CNS/ATM and Avionics (CNS + A) systems and associated cyber-physical architectures for Space Traffic Management (STM).

- by Roberto Sabatini and +1
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- Transportation Engineering, Aerospace Engineering, Space Sciences, Aeronautical Engineering

A unified approach to cooperative and non-cooperative Sense-and-Avoid (SAA) is presented that addresses the technical and regulatory challenges of Unmanned Aircraft Systems (UAS) integration into non-segregated airspace. In this paper, state-of-the-art sensor/system technologies for cooperative and non-cooperative SAA are reviewed and a reference system architecture is presented. Automated selection of sensors/systems including passive and active Forward Looking Sensors (FLS), Traffic Collision Avoidance System (TCAS) and Automatic Dependent Surveillance – Broadcast (ADS-B) system is performed based on Boolean Decision Logics (BDL) to support trusted autonomous operations during all flight phases. The BDL adoption allows for a dynamic reconfiguration of the SAA architecture, based on the current error estimates of navigation and tracking sensors/systems. The significance of this approach is discussed in the Communication, Navigation and Surveillance/Air Traffic Management and Avionics (CNS+A) context, with a focus on avionics and ATM certification requirements. Additionally, the mathematical models employed in the SAA Unified Method (SUM) to compute the overall uncertainty volume in the airspace surrounding an intruder/obstacle are described. In the presented methodology, navigation and tracking errors affecting the host UAS platform and intruder sensor measurements are translated to unified range and bearing uncertainty descriptors. Simulation case studies are presented to evaluate the performance of the unified approach on a representative UAS host platform and a number of intruder platforms. The results confirm the validity of the proposed unified methodology providing a pathway for certification of SAA systems that typically employ a suite of non-cooperative sensors and/or cooperative systems.

- by Roberto Sabatini and +2
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- Robotics, Aerospace Engineering, Robotics (Computer Science), Sensors and Sensing

The IATA predicts 88 percent recovery of Airline Traffic in 2022. And Deloitte forecasts the Aerospace/Space Transportation sector to grow at about 15 percent per year. With our — MAC Global Startup's — help we can both sustain passenger and freight volume, and accelerate our Aerospace Transportation sector ten-to-a-hundred-fold. In the short term! Infinitely more importantly, we can reduce the cost/inefficiency of the Airline Industry several-fold, and the cost and ecocide footprint of the Aerospace Industry a hundred-to-a-thousand-fold! This is our first draft plan for facilitating total transparency and collaboration in the worldwide Airline/Aerospace Industry, and an end to the Century-long Feudal (Warfare) State blockade of low-cost Air-and-Space flight. [Beginning with a planetwide 'naming' competition for 'MAC Global'?] https://twitter.com/MillenniumTwain

This paper presents the conceptual design of a Virtual Pilot Assistant (VPA) for single-pilot operations of commercial transport aircraft. In particular, a thorough requirement analysis was performed by taking into account existing literature on single pilot operations from general aviation and military standards. The analysis also considers relevant human factors engineering and system design aspects of conventional two-pilot aircraft and Remotely-Piloted Aircraft Systems (RPAS). The VPA performs a real-time assessment of the single-pilot's cognitive states and provides useful and timely alerts based on predictions on the performance levels of the pilot. In case of pilot incapacitation, the VPA enables the single-pilot aircraft to be operated as an RPAS, allowing ground operators to take over as necessary and make an emergency landing at a safe and suitable location.

- by Saif Ali
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- Engineering, Aerospace Engineering, Aeronautical Engineering, Aerospace

dynamics of flight Stability and Control (Bernard Etkin)

Critical Mach number & Drag Divergence, drag reduction & lift
augmentation – Sweep, winglets, Flaps, slats and vortex generators.
Propellers: Concept of slip stream with only axial velocity, Actuator disk
theory due to Rankine & Froude; power & thrust coefficients, propeller
twist blade element analysis , blade angle, advance ratio and Torque
coefficient , efficiency , propeller charts.

- by SHIVA PRASAD U
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- Aerospace Engineering, Air Transport, Aerodynamics, Low Speed Aerodynamics

This paper explores the synergies between a novel Global Navigation Satellite System (GNSS) Avionics-Based Integrity Augmentation (ABIA) system and current Space and Ground Based Augmentation Systems (SBAS and GBAS). The ABIA Integrity Flag Generator (IFG) is designed to provide caution and warning integrity flags (in accordance with the specified time-to-caution and time-to-warning requirements) in all relevant flight phases. The ABIA IFG performances are assessed and compared with the SBAS and GBAS integrity flag generation capability. Simulation case studies are presented using the TORNADO-IDS platform and they provide insights on possible mutual benefits attainable by integrating ABIA with SBAS and GBAS systems. The results show that the proposed integrated scheme is capable of performing high-integrity tasks when GNSS is used as the primary source of navigation data. Furthermore, it is evident that there is a clear synergy of ABIA with SBAS and GBAS in providing suitable (predictive and reactive) integrity flags in all flight phases. The integration is thus a clear opportunity for future research towards the development of a Space-Ground-Avionics Augmentation Network (SGAAN) for a number of safety-critical aviation applications.

Unmanned Aircraft Systems (UAS) offer many opportunities in a wide range of industries to support remote sensing and surveillance. While platform autonomy and intelligence have seen large advances in recent decades, a key challenge is the operation of multiple Unmanned Aerial Vehicles (UAV) by a single operator in 'one-to-many' operations. To support one-to-many operations, higher levels of human-autonomy teaming are required, where human operators collaborate with autonomous agents through the use of adaptive Human-Machine Interfaces and Interactions (HMI2). In this paper, the one-to-many concept is applied to a bushfire-fighting scenario. The paper presents the UAV avionics systems design along with the Ground Control Station (GCS) design, which features a number of emerging HMI2 concepts.

- by Roberto Sabatini and +1
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- Aerospace Engineering, Human Computer Interaction, Ergonomics, Aeronautical Engineering

Hybrid-Electric Propulsion Systems (HEPS) have emerged as a promising area of research in aerospace engineering as they combine the complementary advantages of internal combustion and electric propulsion technologies while limiting the environmental emissions. Despite the promising benefits, the insufficient energy densities and specific energies of electrical storage devices are major challenges as they induce severe weight and volume penalties. Significant opportunities are nonetheless emerging thanks to optimised propulsive profiles, energy harvesting techniques and more electric aircraft technologies. To support further research on hybrid electric aircraft, the aim of this study is to develop a HEPS retrofit design methodology for existing Remotely Piloted Aircraft Systems (RPAS). The implemented HEPS models use power state variables, allowing more accurate predictions of energy converter efficiency than with power-based approaches. Data from commercially available products is introduced and a case study is presented assuming a reference RPAS platform and performing parametric studies for traditional, electric and hybrid configurations. Range and endurance performances are investigated in depth and the most significant dependencies on design parameters are analysed. The results suggest that HEPS technology represents a viable trade-off solution in small-to-medium size RPAS, promoting the mitigation of noxious and greenhouse emissions while providing adequate range and endurance performance.

- by Roberto Sabatini and +1
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- Electrical Engineering, Electronic Engineering, Aerospace Engineering, Energy Economics

This invited keynote paper addresses contemporary issues in Air Traffic Management (ATM) focusing on the crucial challenge currently faced by the aviation industry: enhancing safety, efficiency and environmental sustainability of the sector in an era of steady air traffic growth. The aim is to foster opportunities for industrial innovation and multidisciplinary research collaboration in areas of strategic interest such as future systems for Air Traffic Flow Management (ATFM), Dynamic Airspace Management (DAM) and cooperative/non-cooperative surveillance, towards establishing a coherent framework for the evolution of the ATM sector. Taking the move from SESAR / Clean Sky and NextGen top-level operational and technical requirements, the paper presents integrated CNS+A system architectures implementing 4D Trajectory Optimisation (4DTO) algorithms, data link communications and enhanced surveillance technologies, as well as adaptive forms of Human-Machine Interface and Interaction (HMI 2), allowing the automated negotiation and validation of aircraft intents for safer and more efficient ATM operations. As an integral part of this CNS+A evolutionary process, specific requirements for Remotely Piloted Aircraft Systems (RPAS) cooperative/non-cooperative Detect-and-Avoid (DAA) are being addressed in order to allow the safe and unrestricted access of RPAS to all classes of airspace.

The Global Navigation Satellite System (GNSS) supports a growing number of Intelligent Transport System (ITS) applications and location based services including collision avoidance, electronic toll collection, fleet management and Unmanned Aircraft System (UAS) navigation. This paper performs a detailed performance analysis of GNSS with a focus on failure modes in urban environments as a critical case study. A guidance-based augmentation strategy based on trajectory optimization is developed which accounts for the influence of urban structures on GNSS performance. A simulation case study representative of UAS operations in urban environments was performed as a preliminary assessment to corroborate the developed modules.

The design, development, test and evaluation of Unmanned Aerial Systems (UAS) are evolving to meet the requirements for integration into civil airspace. These requirements fall under the umbrella of Communications, Navigation, Surveillance and Air Traffic Management (CNS/ATM), the framework for the evolution of next-generation ATM systems. To meet these requirements, improved/specific formats and functions have to be developed for UAS to allow interoperability within current manned and unmanned platform operations. Additionally, greater system autonomy will afford UAS operators the higher levels of control required for airspace integration. Appropriate human-machine interfaces (HMI) are necessary to complement operator performance as well as to prevent human error and automation surprise. The design of such interfaces is still undergoing fluid change. This paper discusses the different modes of UAS operation and outlines the corresponding cognitive demands for each mode. In manned-unmanned aircraft coordinated operations, unanticipated mode transitions are likely to lead to operator mode confusion and have serious safety implications. Appropriate transitions between operating modes are identified for operational safety and efficiency. To achieve such transitions, the paper proposes a cognitive interface to assess, in real-time, the operator's performance and mental state. Such assessment can support in driving mode transitions, which augment the operator's situational awareness, stress, mental work-load and fatigue levels.

- by Roberto Sabatini
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- Electronic Engineering, Robotics, Aerospace Engineering, Cognitive Psychology

The introduction of dedicated software functions for separation assurance and collision avoidance in Next Generation Flight Management Systems (NG-FMS) has the potential to enable significant advances in the Unmanned Aircraft System (UAS) Traffic Management (UTM) operational context. In this paper, key elements of the NG-FMS architecture are presented that allow planning and optimisation of 4-dimensional trajectories. The NG-FMS is designed to be fully interoperable with a future ground based 4DT Planning, Negotiation and Validation (4-PNV) system, enabling automated Trajectory/Intent-Based Operations (TBO/IBO). This paper addresses one of the key technological challenges for integrating UAS in non-segregated airspace by implementing suitable hardware and software (data fusion) techniques for cooperative and non-cooperative separation assurance and collision avoidance tasks. The sensor/system providing the most reliable separation maintenance and collision avoidance solution is automatically selected and this approach provides robustness in all flight phases supporting all-weather and trusted autonomous operations. The mathematical algorithms employed in the unified approach to cooperative and non-cooperative separation assurance and collision avoidance scenarios are presented. In this method, navigation and tracking errors affecting the host platform and intruder sensor measurements are translated to unified range and bearing uncertainty descriptors. Simulation case studies are presented, including UTM elements such as dynamic geo-fencing, and the results corroborate the validity of separation assurance and collision avoidance algorithms for the considered mission-and safety-critical tasks.

- by Roberto Sabatini and +1
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- Robotics, Aerospace Engineering, Aeronautical Engineering, Unmanned Aircraft Systems
- by Roberto Sabatini
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- Robotics, Aerospace Engineering, Aeronautical Engineering, GPS Applications

Sandwich panels are increasingly used in aircraft structures due to their high specific bending stiffness and hence excellent buckling stability. The objective of this work is to find rough sizing process of a composite sandwich panel incorporating multi-scale modelling techniques to substantiate structural capability of each level of test pyramid, and find a minimum number of tests required to validate the approaches. The numerical analysis of such hybrid structures by means of the finite element method (FEM) requires specific strategies regarding the degree of homogeneity of each component. The common modelling approach for solid laminate of carbon fibre reinforced plastics (CFRP) structures using an extended layered shell element formulation can also be applied in modelling of sandwich panels in the global FE-model. The sandwich core, which is thicker compared to the solid laminate CFRP skins, can be formulated as an additional layer between the two face skin layers. For more detailed modelling of the sandwich structure, e.g. a cut out of the global FE model (GFEM), a solid shell approach can be applied. Both of the monolithic skins are idealised using layered shell, while the sandwich core is represented by solid elements. For a hard foam core the solid elements are assigned to the core system according to their type, isotropic material for unreinforced foam or homogenised, anisotropic properties for a reinforced foam core system. The homogenised mechanical properties of the reinforced foam core can be determined using analytical or numerical approaches, in which for a numerical approach the textile profile or needles shaped foam reinforcements are modelled with shell and beam elements respectively. With some modifications the meso-mechanical FE-model can further be used e.g. through the application of explicit FEM for the determination of an impact damage or using the virtual crack closure technique (VCCT) method and a higher level of FE discretisation to assess the growth behaviour of damages. The non-linear FE analyses show a good agreement with the recorded panel deformations.

- by ichwan zuardy
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- Mechanical Engineering, Aerospace Engineering, Mechanics, Structural Engineering

Propagation of sound waves through compressible fluids, Sonic velocity
and Mach number; Application of continuity, momentum and
energy equations for steady state conditions; steady flow through
nozzle, Effect of varying back pressure on nozzle performance, Critical
pressure ratio Normal shocks, basic equations of normal shock, change
of properties across normal shock.

- by SHIVA PRASAD U
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- Aerospace Engineering, Aeronautical

Provision of GNSS Avionics Based Integrity Augmentation (ABIA) in Unmanned Aerial Vehicles (UAV) Sense-and-Avoid (SAA) architectures has the potential to provide an integrity-augmented SAA solution suitable for cooperative and non-cooperative scenarios where GNSS is used as the primary source of navigation and/or surveillance data (e.g, employing ADS-B). In this paper, we evaluate the opportunities offered by this integration, proposing a novel architecture that maximizes the synergies between ABIA and SAA functionalities in UAV applications. The performance of this Integrity-Augmented SAA (IAS) architecture was evaluated by simulating manned/unmanned platforms with different dynamics in representative cooperative and non-cooperative scenarios. The numerical results demonstrate that the proposed IAS architecture is capable of performing high-integrity conflict detection and resolution when GNSS is used as the primary source of navigation and/or surveillance data.

- by Roberto Sabatini
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- Aerospace Engineering, Aeronautical Engineering, Electronics, GPS Applications
- by Enrica Bodrato
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- Archives, Aeronautical

Whereas current aerospace Human-Machine Interfaces and Interactions (HMI2) are mostly static in their behaviour/appearance and require direct input from human operators, innovative HMI2 concepts are being proposed which allow for multimodal interactions or sense the functional state of human operators and dynamically adapt the level of automation. In particular, to facilitate trust between the human and machine, such systems need sensors that can reliably detect changes in the operator state. However, a number of environmental factors can affect the sensor's accuracy and precision. When used together with other novel sensors, eye tracking has a significant potential to enhance the adaptiveness of aerospace HMI2. This paper presents the activities carried out to quantify the uncertainty associated with eye tracking equipment available in the Avionics and Air Traffic Management (ATM) systems laboratory of RMIT University, which is being used to support the development of Cognitive HMI2. The presented methodology is used to characterise its measurement uncertainty based on a number of considerations, including the calibration error as well as gaze angle in static and dynamic conditions. The uncertainty associated with the eye tracker is used for error budgeting of a Cognitive HMI2 system which employs fuzzy logics to infer operator cognitive states based on eye tracking inputs.

In recent years, the degree of vehicle automation is continuously increasing in all modes of transport. Automated Guided Transport (AGT) systems, which were conceptualised a couple of decades ago are now being realised as unmanned aircraft systems and autonomous ground/sea vehicles. Autonomous ground vehicles are an emerging tool that provide a safer, more cost-effective and sustainable alternative to traditional methods. Furthermore, they offer the capability to detect, alert and compensate for any deviations from the required system performance. In this paper, the system architecture and mathematical modeling of a Global Navigation Satellite System (GNSS) based Navigation and Guidance System (NGS) for autonomous airport surface vehicle operations is presented. Specifically, an integrity augmentation system is implemented in the NGS by modeling the key GNSS error sources (including masking, multipath and signal attenuation). The GNSS based integrity augmentation system is designed to be capable of monitoring the Required Navigation Performance (RNP) and providing usable and timely alerts (by the generation of caution and warning flags). The system is also capable of issuing suitable steering commands to an on-board trajectory re-optimization module; in the event of GNSS signal degradations or losses. One of the key focuses is on modelling the multipath error, which is determined using a ray tracing algorithm. The vehicle position error is obtained as a function of relative geometry between the satellites, receiver antenna and reflectors in realistic airport ground operation environment. Additionally, the airside surface vehicle dynamics and reflective surfaces of buildings located in the airport premises are modelled in order to simulate a 2D trajectory (assuming a flat surface) in a representative airport scenario. Simulation results corroborate the validity of the mathematical models developed for the GNSS based integrity augmentation system, as well as the capability of the system to generate predictive and reactive alerts.

- by Roberto Sabatini and +1
- •
- Robotics, Aerospace Engineering, Mobile Robotics, Aeronautical Engineering

This paper presents performance analyses of the model-scale ERICA and TILTAERO tiltrotors and of the full-scale XV-15 rotor with high-fidelity computational fluids dynamics. For the ERICA tiltrotor, the overall effect of the blades on the fuselage was well captured, as demonstrated by analysing surface pressure measurements. However, there was no available experimental data for the blade aerodynamic loads. A comparison of computed rotor loads with experiments was instead possible for the XV-15 rotor, where CFD results predicted the FoM within 1.05%. The method was also able to capture the differences in performance between hover and propeller modes. Good agreement was also found for the TILTAERO loads. The overall agreement with the experimental data and theory for the considered cases demonstrates the capability of the present CFD method to accurately predict tiltrotor flows. In a second part of this work, the validated method is used for blade shape optimisation.

- by George Barakos
- •
- Engineering, Aeronautical

As Unmanned Aircraft Systems (UAS) technology matures, and the demand for UAS commercial operations is gradually increasing, a widespread proliferation of UAS operations may lead saturation of the airspace resources. Such congestion instances would increase the time-criticality of UAS Traffic Management (UTM) interventions and likely reduce operational efficiency and safety. Therefore, innovative tools and services are needed to deliver Demand and Capacity Balancing (DCB) services in a range of airspace regions, thus increasing operational efficiency and safety while also reducing the time-criticality of UTM operator's duties. The research presented in this paper aims to develop an efficient and uncertainty-resilient DCB process and solution framework based on hybrid learning algorithms, which allows UTM systems to satisfy the operational requirements of UAS in dense metropolitan regions. The focus of this particular paper is on the analysis of uncertainty factors affecting UAS trajectory conformance in the urban and suburban low-altitude airspace and on the requirements which these factors pose on the determination of recommended DCB processes and techniques. Capitalising on these findings, this research will try to improve the safety, efficiency and uncertainty-resilience of UAS traffic in low-altitude urban airspace operations.

This paper gives a brief overview of sandwih application history in general and present composite sandwich structures at Airbus. Current R&D developments for sandwich in primary structure s are being outlined followed by a discussion of... more

This paper proposes a novel risk management framework, and specifically a methodology to model UAS collision risk. The model inherently accounts for the performance of Communication, Navigation and Surveillance (CNS) systems, as well as aircraft vehicle dynamics in evaluating collision risk. The model is applicable to encounters between two or more aircraft, and to terrain collision scenarios. The methodology is underpinned by modelling of the CNS error characteristics, as well as wind uncertainty, and the translation of those characteristics to the spatial domain to form a virtual risk protection volume around each aircraft. The volume is then inflated in proportion to a Target Level of Safety (TLS). The methodology is demonstrated in a simulation case study representative of aircraft-aircraft collision encounters. A 2σ navigation accuracy bound of 185.2 m was found to incur a maximum collision risk of approximately 1.5×10-4 at a separation of 200m.

RefDoc Bienvenue - Welcome. Refdoc est un service / is powered by. ...

- by Konstantinos Kyprianidis
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- Engineering, Aerospace Engineering, Thermodynamics, Modeling

This paper reviews the main hardware/software characteristics and the numerical simulations performed to validate the functionalities of an obstacle warning and avoidance system for various manned and unmanned platform applications. The Laser Obstacle Avoidance and Monitoring (LOAM) system is one of the key non-cooperative sensors adopted for avoiding obstacles/intruders. Robust multi-criteria decision logics are adopted to identify the optimal avoidance manoeuvre considering all currently and previously detected obstacles by employing a so-called history function. Additionally, a new formulation is adopted for defining the overall uncertainty volumes associated with the detected obstacles. The demonstrated detection performances and the robust trajectory generation algorithm ensure a safe avoidance of all classes of obstacles (i.e. ground and aerial) in most weather conditions and flight phases.

- by Subramanian Ramasamy and +1
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- Aerospace Engineering, Aeronautical Engineering, Laser, Electronics

Disclosure of Science of Eighty-year History of SpacePlane Flight ...

- by Millennium Twain
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- Engineering, Electrical Engineering, Mechanical Engineering, Civil Engineering

The purpose of the research presented here is to exploit actuation via smart materials to perform shape control of an aerofoil on a small aircraft and to determine the feasibility and advantages of smooth control surface deformations. A type of piezoceramic composite actuator known as Macro-Fiber Composite (MFC) is used for changing the camber of the wings. The MFC actuators were implemented on a 30° swept wing, 0·76m wingspan aircraft. The experimental vehicle was flown using two MFC patches in an elevator/aileron (elevon) configuration. Preliminary flight and wind-tunnel testing has demonstrated the stability and control of the concept. Flight tests were performed to quantify roll control using the MFC actuators. Lift and drag coefficients along with pitch and roll moment coefficients were measured in a low-speed, open-section wind tunnel. A vortex-lattice analysis complemented the database of aerodynamic derivatives used to analyse control response. The research, for the first ti...

- by D. J . Inman
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- Engineering, Aerodynamics, Smart Materials, Lattice Beam Model

An aircraft structural assembly includes an area element which has a core and an outer layer. A first surface of the area element is convexly curved, at least in certain sections, relative to an imaginary central area of the area element... more

This paper intends to develop a target trajectory estimation algorithm with application to the ballistic target estimation in the terminal phase. The proposed design is based on the application of a second-order extended state observer (ESO) technique using target information acquired from the seeker to estimate the trajectory of manoeuverable ballistic targets. Satisfactory results have been received while applying the design in estimation of either two-dimenional or three-dimentional target evasive acceleration via computer simulation.

- by Chun-Liang Lin
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- Engineering, Computer Science, Aeronautical

We would like to invite you to join this exciting new project as a chapter contributor on one of the topics listed below. Since this is a textbook, a great deal of this chapter entails a survey on the topic under the paradigm of cyber-physical systems, what can be done onboard and remotely, the distributed nature of the system and some exercises on futurology (anticipating trends can shed some light on upcoming designs). IET will bring great visibility to your work. Each chapter should be around 20-25 pages each and can be submitted as a Word or Latex File. The IET will send you additional info (formatting, permission form, etc.) with the contributor's agreement once you have decided to contribute to the book. Visit http://www.theiet.org/resources/author-hub/books/index.cfm to get all contributor's information to an IET research-level book. Each book is expected to have a total number of 500 printed pages (with approximately 550 words per page and a 20% allowance for figures and tables). We have included a tentative schedule and list of topics below. If this is something you would consider, please send us the title of your chapter, a short description/abstract of the chapter content, and your full contact details. We will expect original content and new insights for this book. You can, of course, reuse published material but the percentage of material reuse for the chapter should be less than 40%. The IET will run a piracy software on the full manuscript to control that you are including original material and will reject chapters who contain a large amount of already-published material so please do take this into consideration. We would appreciate your feedback by December 31, 2017. Please do not hesitate to contact us if you have any queries. We look forward to working with you towards the successful publication.

- by Vania V Estrela and +1
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- Robotics, Control Systems Engineering, Scientific Visualization, Robotics (Computer Science)