CTF3 is a test facility for a new CLIC high energy linear collider. For this beamsteering and beam focusing is vital. Because physically running a beamline and changingsetup is expensive and takes much effort it is beneficial to use a simulator for thebeamline. The transportation of the beam through the beamline can be representedwith matrix multiplications and for this reason MATLAB is a fitting environment tosimulate in. A Flight Path Simulator was written in MATLAB and was succefullyimplemented and tested for the CALIFES beamline of the two-beam test stand that ispart of the CTF3 facility.

CTF3 is a test facility for a new CLIC high energy linear collider. For this beamsteering and beam focusing is vital. Because physically running a beamline and changingsetup is expensive and takes much effort it is beneficial to use a simulator for thebeamline. The transportation of the beam through the beamline can be representedwith matrix multiplications and for this reason MATLAB is a fitting environment tosimulate in. A Flight Path Simulator was written in MATLAB and was succefullyimplemented and tested for the CALIFES beamline of the two-beam test stand that ispart of the CTF3 facility. / <p>återuppladdning</p>

This thesis describes the design of a data structure for use with Digitised Terrain Elevation Data (DTED) in Terrain Reference Navigation (TRN) systems. The data structure is based on a variant of quad-tree and oct-tree data structures to provide an efficient representation of terrain in terms of storage requirements and acccss operations. These data structure are applied to flight path planning operations in mission management applications. The algorithms developed for flight path planning have becri implemented in the C programming language for a standard PC. Current research in TRN systems is reviewed and attention is given to the use of hierarchical data structures to cope with the potentially large data base needed for DTED files. Data structure combining quad-trees and oct-trees are developed with an emphasis on data reduction using pointerless trees and the use of locational codes to provide straightforward mapping between quad-trees and oct-trees, in other words, between two-dimensional co-ordinates and three-dimensional co-ordinates. Analysis of these algorithms is described for two DTED files to illustrate storage improvements and to verify a set of database access operations. These data structures are applied to problems of flight path planning where the navigation space comprises objects above a specific altitude and this three-dimensional space is searched for a flight path which avoids the obstacles and satisfies specific operational criteria. Algorithms are developed to extract a visibility graph from the terrain database and to determine the preferred flight path from a set of paths which satisfy defined constraints. Several search techniques are developed which exploit the efficiency of the quad-tree and oct-tree data structures. These methods are extended to real-time flight-path planning where predicted times for access operations are used to direct flight path extraction by varying the tree resolution during computation of the flight path. A comprehensive set of results are provided to illustrate: the storage efficiency of quad-tree and oct-tree data structures the application of pyramid structures to represent navigation space analysis of the time to compute the visibility graph and to extract flight paths integration of these methods with a real-time mission management simulation on a PC The thesis draws conclusions on the efficiency of these techniques for the represcntation of DTEDs and to access objects in TRN systems. It is observed that the use of hierarchical data structures in the form of quad-trees and oct-trees offers significant improvement in accessing DTEDS, for future use in TRN systems. The thesis concludes by outlining areas of further work where the techniques can be further &N, cloped for applications in mission management and navigation using DTED files.

In this thesis, we describe a method for controlling the cycle-averaged velocity direction of a fixed-wing aircraft in an unpowered, helical descent. While the aircraft propulsion system is disabled, either intentionally or due to a failure, the aerodynamic control surfaces (aileron, elevator, and rudder) are assumed to be functional. Our approach involves two steps: (i) establishing a stable, steady, helical motion for which the control surfaces are not fully deflected and (ii) modulating the aircraft control surfaces about their nominal positions to ``slant'' the helical flight path in a desired direction relative to the atmosphere, whether to attain a desired impact location, to counter a steady wind, or both. The effectiveness of the control law was evaluated in numerical simulations of a general transport model (GTM). / Master of Science / When an unmanned aircraft is near an authorized airspace (a region of space where the aircraft is not authorized to fly) and experiences a failure such as loss of communication with the control tower,or failure of the GPS or propulsion system, then the aircraft is generally put into an aerodynamic flight termination. In this flight termination method, the aircraft propulsion system is switched off and the control surfaces (aileron, elevator and rudder) are fixed to induce a spin in the aircraft causing it to descend in a helical fashion. However, in the presence of external gusts the aircraft might drift into the unauthorized airspace; or once the aircraft is put into spin, one may want to be able to change the impact location to a safer place. To the best of our knowledge, there exist no control strategies to alter the impact location of the aircraft once it is put into spin and while is continues to spin. In this thesis we describe a method to do so. The aircraft impact location is altered by controlling the cycle-averaged velocity direction of a fixed-wing aircraft in an unpowered, helical descent. While the aircraft propulsion system is disabled, either intentionally or due to a failure, the aerodynamic control surfaces (aileron, elevator, and rudder) are assumed to be functional. Our approach involves two steps: (i) establishing a stable, steady, helical motion for which the control surfaces are not fully deflected and (ii) modulating the aircraft control surfaces about their nominal positions to “slant” the helical flight path in a desired direction relative to the atmosphere, whether to attain a desired impact location, to counter a steady wind, or both. The effectiveness of the control law was evaluated in numerical simulations of a general transport model (GTM).

A major factor that negatively impacts flight operations globally is adverse weather. To reduce the impact of adverse weather, avoidance procedures such as finding an alternative flight path can usually be carried out. However, such procedures usually introduce extra costs such as flight delay. Hence, there exists a need for alternative flight paths that efficiently avoid adverse weather regions while minimising costs. Existing weather avoidance methods used techniques, such as Dijkstra’s and artificial potential field algorithms that do not scale adequately and have poor real time performance. They do not adequately consider the impact of weather and its avoidance on passengers. The contributions of this work include a new development of an improved integrated model for weather avoidance, that addressed the impact of weather on passengers by defining a corresponding cost metric. The model simultaneously considered other costs such as flight delay and fuel burn costs. A genetic algorithm (GA)-based rerouting technique that generates optimised alternative flight paths was proposed. The technique used a modified mutation strategy to improve global search. A discrete firefly algorithm-based rerouting method was also developed to improve rerouting efficiency. A data framework and simulation platform that integrated aeronautical, weather and flight data into the avoidance process was developed. Results show that the developed algorithms and model produced flight paths that had lower total costs compared with existing techniques. The proposed algorithms had adequate rerouting performance in complex airspace scenarios. The developed system also adequately avoided the paths of multiple aircraft in the considered airspace.

Aircraft flight test data are processed by optimal estimation programs to estimate the aircraft state trajectory (3 DOF) and to identify the unknown parameters, including constant biases and scale factor of the measurement instrumentation system. The methods applied in processing aircraft flight test data are the iterative extended Kalman filter/smoother and fixed-point smoother (IEKFSFPS) method and the two-step estimator (TSE) method. The models of an aircraft flight dynamic system and measurement instrumentation system are established. The principles of IEKFSFPS and TSE methods are derived and summarized, and their algorithms are programmed with MATLAB codes. Several numerical experiments of flight data processing and parameter identification are carried out by using IEKFSFPS and TSE algorithm programs. Comparison and discussion of the simulation results with the two methods are made. The TSE+IEKFSFPS combination method is presented and proven to be effective and practical. Figures and tables of the results are presented.

Les infrastructures linéaires de transports (ILT), dont les routes, sont une des principales causes du déclin de la biodiversité. Bien que les évaluations environnementales permettent de limiter ce déclin, la séquence "Eviter, Réduire et Compenser" les impacts peine à s'appliquer pleinement. En effet, la séquence ERC fait bien souvent appel à des données qualitatives en oubliant les processus biologiques et/ou écologiques et leur échelle spatio-temporelle. L'impact des routes est globalement bien documenté pour plusieurs groupes biologiques, hormis pour les chauves-souris, pourtant susceptibles d'être très fortement affectées. Par ailleurs, leur protection stricte nécessite leur prise en compte dans la séquence ERC. Pour étudier l’impact des routes, et notamment des autoroutes, je me suis concentré sur l’étude des chauves-souris afin de mesurer et quantifier leur magnitude. Pour cela, différentes méthodes développées et réutilisables par les différents acteurs de terrain seront présentées. Ainsi, dans un premier temps, je me suis intéressé à une méthode de traitement des données issues d'écoutes acoustiques et à une méthode de valorisation. Dans un second temps, nous avons appliqué ces méthodes afin (i) de connaitre quels étaient les impacts des routes sur les populations de chauves-souris et (ii) afin d'évaluer l'efficience des mesures de réductions engagées pour réduire ces impacts. Nos principaux résultats montrent que les autoroutes ont un impact négatif significatif sur l'activité de chasse et de transit pour plusieurs espèces de chauves-souris jusqu'à au moins cinq kilomètres de distance à une autoroute. De plus, l'effet des autoroutes semblerait également avoir des conséquences sur la génétique des populations. Enfin, nous avons étudié les chiroptéroducs, ouvrages dédiés aux chauves-souris visant à réduire ces impacts par l'amélioration des connectivités écologiques. Ce type d'ouvrage dédié semble être approprié lorsqu'il est situé dans des corridors écologiques fins tels que les haies. / Biodiversity is being lost at an increased rate as a result of human activities. One of the major threats to biodiversity is infrastructural development. Although the measures taken in environmental impact assessments can limit this loss, the mitigation hierarchy to "Avoid, Reduce and Offset" impacts on biodiversity is not fully functional. Indeed, the mitigation hierarchy often uses qualitative data and does not account for the biological and/or ecological processes and their different spatial and temporal scales. The impact of roads is well documented for several biological groups but not for bats whereas they are likely to be very strongly affected. Moreover, as they are strictly protected, they should be considered in the mitigation hierarchy. Therefore, through the study of bats, I investigated the effects of roads, especially major roads, and intended to measure and quantify the magnitude of their impacts. This thesis presents different methods developed to reach this objective and which may be used by stakeholders in the field. First, I intended to determine how to process data collected through passive acoustic monitoring and how to exploit these data. Then I determined what the impacts of roads on bat populations are and I proposed a method in order to assess the mitigation measures which presume to restore bat habitat connectivity. Our main results show a significant negative effect of roads on bats foraging and commuting behaviour for several species and up to at least five kilometres away from a major road. In addition, the effect of major roads also seems to have consequences on populations’ genetics. Finally, we studied bat overpasses which are structures specifically dedicated to bats and aiming at reducing the impacts of roads by improving bats’ habitat connectivity. These structures seem to be appropriate when located in narrow ecological corridors such as hedgerows.

In this thesis, energy optimal route of an unmanned solar powered air vehicle is obtained for the given mission constraints in order to sustain the maximum energy balance. The mission scenario and the constraints of the solar powered UAV are defined. Equations of motion are obtained for the UAV with respect to the chosen structural properties and aerodynamic parameters to achieve the given mission. Energy income and loss equations that state the energy balance, up to the position of the UAV inside the atmosphere are defined. The mathematical model and the cost function are defined according to the mission constraints, flight mechanics and energy balance equations to obtain the energy optimal path of the UAV. An available optimal control technique is chosen up to the mathematical model and the cost function in order to make the optimization. Energy optimal path of the UAV is presented with the other useful results. Optimal route and the other results are criticized by checking them with the critical positions of the sun rays.

Direct lift control for aircraft has been around in the aeronautical industry for decades but is mainly used in commercial aircraft with dedicated direct lift control surfaces. The focus of this thesis is to investigate if direct lift control is feasible for a fighter aircraft, similar to Saab JAS 39 Gripen, without dedicated control surfaces. The modelled system is an aircraft that is inherently unstable and contains nonlinearities both in its aerodynamics and in the form of limited control surface deflection and deflection rates. The dynamics of the aircraft are linearised around a flight case representative of a landing scenario. Direct lift control is then applied to give a more immediate relation from pilot stick input to change in flight path angle while also preserving the pitch attitude. Two different control strategies, linear quadratic control and model predictive control, were chosen for the implementation. Since fighter aircraft are systems with fast dynamics it was important to limit the computational time. This constraint motivated the use of specialised methods to speed up the optimisation of the model predictive controller. Results from simulations in a nonlinear simulation environment supplied by Saab, as well as tests in high-fidelity flight simulation rigs with a pilot, proved that direct lift control is feasible for the investigated fighter aircraft. Sufficient control authority and performance when controlling the flight path angle were observed. Both developed controllers have their own advantages and which strategy is the most suitable depends on what the user prioritises. Pilot workload during landing as well as precision at touch down were deemed similar to conventional control.

In this work we present a novel computational framework for analyzing evolution of uncertainty in state trajectories of a hypersonic air vehicle due to uncertainty in initial conditions and other system parameters. The framework is built on the so called generalized Polynomial Chaos expansions. In this framework, stochastic dynamical systems are transformed into equivalent deterministic dynamical systems in higher dimensional space. In the research presented here we study evolution of uncertainty due to initial condition, ballistic coefficient, lift over drag ratio and atmospheric density. We compute the statistics using the continuous linearization (CL) approach. This approach computes the jacobian of the perturbational variables about the nominal trajectory. The covariance is then propagated using the riccati equation and the statistics is compared with the Polynomial Chaos method. The latter gives better accuracy as compared to the CL method. The simulation is carried out assuming uniform distribution on the parameters (initial condition, density, ballistic coefficient and lift over drag ratio). The method is then extended for Gaussian distribution on the parameters and the statistics, mean and variance of the states are matched with the standard Monte Carlo methods. The problem studied here is related to the Mars entry descent landing problem.