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The aim of this project was to design a flightcontrol system with the purpose of safely guiding a glidertoward a given GPS location over a distance of at least 50km. More specifically, the aim was to develop a control systemfor autonomous gliding and implement it on a given data hubcontaining sensors, GPS-module, microcontroller and a FieldProgrammable Gate Array (FPGA). A SIMULINK simulationenvironment has been developed for simulating flight dynamicsand the digital implementation of some of the on-board hardware.The simulation environment also serves as a platform to tunecontrollers and implement most of the necessary logic forthe control system. For the reference heading, a trigonometricformula is used along with latitude/longitude coordinates tocalculate the turn-angle necessary to travel along the shortestpath between two points. Four negative feedback control loopsare used to track the reference heading and achieve maximumglide ratio. The project has been conducted with mixed success,where the implementation part of the project has suffered greatdrawbacks mainly due to problems in developing the simulationenvironment. In spite of this, the open loop simulation outputspromising results where the glider behaves as expected and isconsidered realistic enough to be a suitable environment in whichto develop a flight control system. In addition, given that thegliders geometry offers reasonable aerodynamic stability, it isshown in this thesis that the proposed control system architectureand heading reference system is sufficient to steer the glider tothe given location under calm atmospheric conditions. / M°alet med detta projekt var att utveckla ettstyrsystem för att på ett säkert sätt styra ett segelflygplan mot engiven GPS-position över ett avstånd på minst 50 km. Mer specifiktvar målet att utveckla ett styrsystem för autonom glidningoch implementera det på en given datahubb som innehållersensorer, GPS-modul, mikrokontroller och programmerbar logik(FPGA). En SIMULINK-simuleringsmiljö har utvecklats föratt simulera flygdynamiken och för digital implementering avnågra av de givna hårdvarukomponenterna. Simuleringsmiljönagerar också som en plattform för att justera regulatorer ochimplementera det mesta av den nödvändiga logiken för styrsystemet.För referensriktning används en trigonometrisk formeltillsammans med latitud/longitud koordinater för att beräknaden sväng-vinkel som krävs för att färdas längs den kortastevägen mellan två punkter. Fyra regulatorer används till attfölja rätt kompassriktining samt maximera flygtid. Projektethar genomförts med blandad framgång, där genomförandet avprojektet har blivit lidande främst på grund av problem medatt utveckla simuleringsmiljön. Trots detta ger simulersmiljönlovande resultat där segelflygplanet beter sig som förväntat ochanses därmed vara en realistisk nog plattform för att utveckla ettkontrollsystem i. Dessutom, givet att geometrin av segelflygplanetger rimlig aerodynamisk stabilitet, framgår det i denna rapportatt den föreslagna styrsystemarkitekturen och referensriktningslogikenär tillräcklig för att styra segelflygplanet till den givnapositionen under lugna atmosfäriska förhållanden. / Kandidatexjobb i elektroteknik 2021, KTH, Stockholm

There have been several accidents involving autonomous vehicles on public roadways under scenarios that are normally avoidable by competent human drivers. This thesis contains a review of these accidents and their causes as a result of inadequate hazard mitigation. As a solution to this problem, a novel design pattern is proposed. This design pattern was developed from a hazard analysis using Systems Theoretic Process Analysis ( STPA ) methodologies that analyzed the circumstances common to several of these accidents. To demonstrate the effectiveness of the novel design pattern, an example system is constructed and tested in simulation against several accident scenarios similar to the ones studied. The results are then explained to demonstrate the effectiveness of the proposed design pattern. / Thesis / Master of Applied Science (MASc)

Due to increasingly difficult threats, current air defense missile systems are pushed to the limits of their performance capabilities. In order to defend against these more stressing threats, interceptor missiles require greater maneuverability, faster response time, and increased robustness to more severe environmental conditions. One of the most critical missile system elements is the flight control system, since its time constant is typically half of the total missile system time constant. Conventional autopilot design techniques have worked well in the past, but in order to satisfy future and more stringent design specifications, new design methods are necessary. Robust control techniques (in particular, H-Infinity Control and Mu-Synthesis) and their application to the design of missile autopilots are addressed in this thesis. In addition, conventional autopilot designs are performed as comparative benchmarks. This paper reviews the missile autopilot design problem and presents descriptions of the classical and H-Infinity/Mu design methods. Missile autopilot designs considering both rigid-body dynamics and elastic-body dynamics are presented. Comparisons of the design approaches and results are also discussed. The results show that the application of robust control techniques to the design of missile autopilots can improve the performance and stability robustness characteristics of the flight control system. / Master of Science

Thesis aims at fighter combat and maneuvring - so called Dogfighting. The purpose of this work is to create intelligent autopilot based on Agent system, eligible of executing in-air maneuvers and tactics in real-time simulation. In the first part, theoretical basis of air combat will be introduced, such as weapon systems, maneuvring and tactics in mutual combat 1 on 1, odds fight 2 on 1, and last but not least mass fights. Also agent programming will be introduced, as well as recognizing of agent rules and processes and its transformation to agent language. The second part describes building of a simple graphical simulation environment based on JMonkey game engine. Agent system maintaining every single aircraft within the simulation will be created and own network socket protocol for communication between intelligent behavior and simulation environment will be discussed and documented.

Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: A strategy for the design of an effective, practically feasible, robust, computationally efficient autopilot for three dimensional manoeuvre flight control of Unmanned Aerial Vehicles is presented. The core feature of the strategy is the design of attitude independent inner loop acceleration controllers. With these controllers implemented, the aircraft is reduced to a point mass with a steerable acceleration vector when viewed from an outer loop guidance perspective. Trajectory generation is also simplified with reference trajectories only required to be kinematically feasible. Robustness is achieved through uncertainty encapsulation and disturbance rejection at an acceleration level. The detailed design and associated analysis of the inner loop acceleration controllers is carried out for the case where the airflow incidence angles are small. For this case it is shown that under mild practically feasible conditions the inner loop dynamics decouple and become linear, thereby allowing the derivation of closed form pole placement solutions. Dimensional and normalised non-dimensional time variants of the inner loop controllers are designed and their respective advantages highlighted. Pole placement constraints that arise due to the typically weak non-minimum phase nature of aircraft dynamics are developed. A generic, aircraft independent guidance control algorithm, well suited for use with the inner loop acceleration controllers, is also presented. The guidance algorithm regulates the aircraft about a kinematically feasible reference trajectory. A number of fundamental basis trajectories are presented which are easily linkable to form complex three dimensional manoeuvres. Results from simulations with a number of different aircraft and reference trajectories illustrate the versatility and functionality of the autopilot. Key words: Aircraft control, Autonomous vehicles, UAV flight control, Acceleration control, Aircraft guidance, Trajectory tracking, Manoeuvre flight control. / AFRIKAANSE OPSOMMING: ’n Strategie vir die ontwerp van ’n effektiewe, prakties haalbaar, robuuste, rekenkundig effektiewe outoloods vir drie dimensionele maneuver vlugbeheer van onbemande vliegtuie word voorgestel. Die kerneienskap van die strategie is die ontwerp van oriëntasie-onafhanklike binnelus-versnellingbeheerders. Hierdie beheerders stel die navigasie buitelus in staat om die voertuig as ’n puntmassa met ’n stuurbare versnellingsvektor te beskou. Trajekgenerasie is ook vereenvoudig deurdat verwysingstrajekte slegs kinematies haalbaar hoef te wees. Robuustheid word verkry deur onsekerhede en versteuringsverwerping op ’n versnellingsvlak te hanteer. Die gedetaileerde ontwerp en saamhangende analise van die binnelus versnellingsbeheerders word uitgevoer vir die geval waar die invalshoeke klein is. Dit word aangetoon dat, onder praktiese omstandighede, die binnelus dinamika ontkoppel kan word en lineêr word, wat die afleiding van geslotevorm poolplasingoplossings toelaat. Dimensionele en genormaliseerde, nie-dimensionele tydvariante van die binnelusbeheerders word ontwerp en hul onderskeidelike voordele word uitgewys. Poolplasing beperkings, wat ontstaan as gevolg van die tipiese geringe nie-minimum fasegedrag van voertuigdinamika, word ontwikkel. ’n Gepaste generiese, voertuig onafhanklike navigasiebeheer algoritme vir gebruik saam met die binnelus-versnellingsbeheerders word voorgestel. Die voertuig word om ’n kinematies haalbare verwysingstrajek deur hierdie navigasie algoritme gereguleer. ’n Aantal fundamentele trajekte word voorgestel wat maklik gekombineer kan word om komplekse drie dimensionele maneuvers te vorm. Die veelsydigheid en funksionaliteit van die outoloods word deur simulasieresultate met ’n verskeidenheid voertuie en verwysingstrajekte gedemonstreer.

The Multiple Simultaneous Specification controller design method is an elegant means of designing a single controller to satisfy multiple convex closed loop performance specifications. In this thesis, the method is used to design pitch and roll attitude controllers for a Zagi flying-wing unmanned aerial vehicle from Procerus Technologies. A linear model of the aircraft is developed, in which the lateral and longitudinal motions of the aircraft are decoupled. The controllers are designed for this decoupled state space model. Linear simulations are performed in Simulink, and all performance specifications are satisfied by the closed loop system. Nonlinear, hardware-in-the-loop simulations are carried out using the aircraft, on-board computer, and ground station software. Flight tests are also executed to test the performance of the designed controllers. The closed loop aircraft behaviour is generally as expected, however the desired performance specifications are not strictly met in the nonlinear simulations or in the flight tests.

The Multiple Simultaneous Specification controller design method is an elegant means of designing a single controller to satisfy multiple convex closed loop performance specifications. In this thesis, the method is used to design pitch and roll attitude controllers for a Zagi flying-wing unmanned aerial vehicle from Procerus Technologies. A linear model of the aircraft is developed, in which the lateral and longitudinal motions of the aircraft are decoupled. The controllers are designed for this decoupled state space model. Linear simulations are performed in Simulink, and all performance specifications are satisfied by the closed loop system. Nonlinear, hardware-in-the-loop simulations are carried out using the aircraft, on-board computer, and ground station software. Flight tests are also executed to test the performance of the designed controllers. The closed loop aircraft behaviour is generally as expected, however the desired performance specifications are not strictly met in the nonlinear simulations or in the flight tests.

In order to have an interception with a target, a missile should be guided with a successful guidance algorithm accompanied with a suitable autopilot structure. In this study, different autopilot and guidance designs for a canard-controlled missile are developed. As a first step, nonlinear missile mathematical model is derived by using the equations of motion with aerodynamic coefficients found by Missile DATCOM program. Autopilot design starts by the linearization of the nonlinear missile model around equilibrium flight conditions. Controllers based on the concepts of optimal control theory results and sliding mode control are designed. In all of the designs, angle of attack command and roll angle command type autopilot structures are used. During the design process, variations in angle of attack, Mach number and altitude can lead to significant performance degradation. This problem is typically solved by applying gain-scheduling methodology according to these parameters. There are different types of guidance methods in the literature. Throughout this study, proportional navigation guidance and its modified forms are selected as a base algorithm in the guidance system design. Other robust forms of guidance methods, such as an optimal guidance approach and sliding mode guidance, are also formed for performance comparison with traditional proportional navigation guidance approach. Finally, a new guidance method, optimal proportional-integral guidance, whose performance is the best among all of the methods included in the thesis against highly maneuvering targets, is introduced.

In this thesis, adaptive neural network controllers are designed for a high subsonic cruise missile. Two autopilot designs are included in the study using adaptive neural networks, namely an altitude hold autopilot designed for the longitudinal channel and a directional autopilot designed for heading control. Aerodynamic coefficients are obtained using missile geometry / a 5-Degree of Freedom (5-DOF) simulation model is obtained, and linearized at a single trim condition. An inverted model is used in the controller. Adaptive Neural Network (ANN) controllers namely, model inversion controllers with Sigma-Pi Neural Network, Single Hidden Layer Neural Network and Background Learning implemented Single Hidden Layer Neural Network, are deployed to cancel the modeling error and are applied for the longitudinal and directional channels of the missile. This approach simplifies the autopilot designing process by combining a controller with model inversion designed for a single flight condition with an on-line learning neural network to account for errors that are caused due to the approximate inversion. Simulations are performed both in the longitudinal and directional channels in order to demonstrate the effectiveness of the implemented control algorithms. The advantages and drawbacks of the implemented neural network based controllers are indicated.