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<p>When flying a fighter aircraft such as the JAS 39 Gripen, the pilot is exposed to high g-loads. In order to prevent the draining of blood from the brain during this stress an anti-g protection system is used. The system consists of a pair of trousers, called the anti-g trousers, with inflatable bladders. The bladders are filled with air, pressing tightly on to the legs in order to prevent the blood from leaving the upper part of the body.</p><p>The purpose of this thesis is to detect if the pressure of the anti-g trousers is deviating from the desired value. This is done by developing a detection algorithm which gives two kinds of alarm. One is given during minor deviations using a CUSUM test, and one is given at grave deviations, based on different conditions including residual, derivative and time. The thresholds, in which between the pressure should lie in a faultless system, are calculated from the g-load value. The thresholds are based upon given static guidelines for the pressure tolerance area and are modified in order to adapt to the estimated dynamics of the system.</p><p>The values of the input signals, pressure and g-load, were taken from real flight sessions. The validation has been performed using both faultless and faulty flight sequences, with low false alarm rate and no missed detections. All together the detection system is considered to work well.</p>

<p>Saab Aerosystems, a part of Saab AB, has the overall responsibility for the development of the fourth generation fighter aircraft JAS 39 Gripen. When planning a mission for one or more aircrafts, a computer program called Mission Support System is used. Some of the data from the planning is then transferred to the actual aircraft. Today there are some unwanted restrictions in the planning software. One of these restrictions is about the fact that a number of parameters that controls the output from a planned mission are not configurable runtime, i.e. a reinstallation at customers location is needed to change this. The main purpose of this thesis was to propose a new design and a new framework that solves the inflexibility described above. The design should also be validated by a test implementation. A number of different designs were proposed and four of these were selected to be candidates for being implemented. An important tool used when developing the designs was the theory of design patterns. To choose one of the four a ranking system, based on both measurable metrics and non-measurable experience, was used. One design was selected to be the best and after implementing of the design it was considered to be valid. Future work can consist of rewriting all modules in the software to use the new framework.</p>

<p>Abstract</p><p>SAAB has for a long time used user controlled pilot models in ARES. ARES is a simulation tool used in the desktop environment for simulations and calculations of the JAS 39 Gripen fighter and other aircraft. ARES stands for ”Aircraft Rigid body Engineering Simulation”. To work with these pilot models has been both time-consuming and inefficient. In this master thesis, new pilot models are developed, where parameters are automatically generated, this will result in that the user doesn’t have to put a lot of work into adjusting the gains for different manoeuvres. This is called gain scheduling.</p><p>To make this possible, simple models of the aircraft were created at different points in the envelope. These models were then used to calculate optimal controllers using LQ-control and pole placement techniques. These models and controllers were then implemented in Simulink. Simulink was then used to test the controllers before they were implemented in ARES.</p><p>Control in all modes except roll attitude and speed by throttle are based on LQ-control in pitch-, roll- and yaw-angular velocity. And through these angular velocities the other angles are controlled by simple controllers, who is generating a reference in angular velocity. The roll attitude controller is based on direct pole placement based upon desired damping and undamped natural frequency, and the speed controller is based upon a model of throttle positions in trimmed states.</p><p>The new pilot models are usable to control:</p><ul><li>Roll rate</li><li>Roll attitude</li><li>Pitch rate</li><li>Pitch attitude</li><li>Angle of attack</li><li>Load factor</li><li>Yaw attitude</li><li>Course angle</li><li>Climb angle</li><li>Mach number</li><li>Climb rate</li></ul><p>These controllers can be combined so that the aircraft can perform desired maneuvers.</p>

Abstract SAAB has for a long time used user controlled pilot models in ARES. ARES is a simulation tool used in the desktop environment for simulations and calculations of the JAS 39 Gripen fighter and other aircraft. ARES stands for ”Aircraft Rigid body Engineering Simulation”. To work with these pilot models has been both time-consuming and inefficient. In this master thesis, new pilot models are developed, where parameters are automatically generated, this will result in that the user doesn’t have to put a lot of work into adjusting the gains for different manoeuvres. This is called gain scheduling. To make this possible, simple models of the aircraft were created at different points in the envelope. These models were then used to calculate optimal controllers using LQ-control and pole placement techniques. These models and controllers were then implemented in Simulink. Simulink was then used to test the controllers before they were implemented in ARES. Control in all modes except roll attitude and speed by throttle are based on LQ-control in pitch-, roll- and yaw-angular velocity. And through these angular velocities the other angles are controlled by simple controllers, who is generating a reference in angular velocity. The roll attitude controller is based on direct pole placement based upon desired damping and undamped natural frequency, and the speed controller is based upon a model of throttle positions in trimmed states. The new pilot models are usable to control: Roll rate Roll attitude Pitch rate Pitch attitude Angle of attack Load factor Yaw attitude Course angle Climb angle Mach number Climb rate These controllers can be combined so that the aircraft can perform desired maneuvers.

Simulation is a vital tool during development of JAS 39 Gripen, since money and time can be saved. The Auxiliary and Emergency Power System, AEPS, is a subsystem of the secondary power system in Gripen. It has the function of providing the aircraft with electrical and hydraulical power before activation and after deactivation of the main engine. The system also functions as backup in case of a safety critical problem in the main power supply system. The system basically consists of a control unit and an auxiliary gearbox. The gearbox is driven by an air turbine. An auxiliary generator and a hydraulic pump are mounted on the gearbox to provide the aircraft with electrical and hydraulical power. The airflow to the turbine is regulated by an Air Modulating Valve, AMV. This report describes a new model of the AEPS. The model encompasses the logical control unit and a physical description of AMV, air turbine, auxiliary gearbox, auxiliary generator and the auxiliary hydraulic pump. The logical model is connected to the physical model whereby simulation of the whole system is made possible. The model is implemented in Matlab/Simulink. This work provides a complete model of the AEPS which enables simulation of the dynamical processes. Verification was done by comparing simulation results with measurements from the real physical system. Satisfactory results are achieved, especially for inlet pressure for the air turbine and the speed of the auxiliary generator. / Simulering är ett viktigt verktyg under utveckling av JAS 39 Gripen, eftersom detta möjliggör att både pengar och tid kan sparas. Reserv- och nödkraftsystemet Auxiliary and Emergency Power System, AEPS, som är en del av Gripens hjälpkraftsystem, har till uppgift att försörja flygplanet med el- och hydraulkraft före uppstart och efter nedstängning av huvudmotor. Systemet fungerar även som backup vid bortfall av ordinarie kraftförsörjning. Grovt förenklat består systemet av en logisk kontrollenhet och en turbindriven reservväxellåda. På reservväxellådan finns en reservgenerator och en reservhydraulpump för elkraft respektive hydraulkraftförsörjning. Luftflödet till turbinen regleras av en så kallad Air Modulating Valve, AMV. Den här rapporten beskriver en ny modell av AEPS. Modellen omfattar den logiska kontrollenheten och en fysikalisk beskrivning av systemets reglerventil, turbin, växellåda, reservgenerator och reservhydraulpump. Den logiska modellen kopplas samman med den fysikaliska och möjliggör simulering av hela systemet. Implementeringen görs i Matlab/Simulink. Arbetet leder fram till en komplett modell för AEPS där dynamiska förlopp beskrivs. Verifiering görs genom att jämföra simuleringar med mätningar från det fysiska systemet. Tillfredställande resultat uppnås, speciellt för tryck in till turbin och varvtal för reservgenerator.

When flying a fighter aircraft such as the JAS 39 Gripen, the pilot is exposed to high g-loads. In order to prevent the draining of blood from the brain during this stress an anti-g protection system is used. The system consists of a pair of trousers, called the anti-g trousers, with inflatable bladders. The bladders are filled with air, pressing tightly on to the legs in order to prevent the blood from leaving the upper part of the body. The purpose of this thesis is to detect if the pressure of the anti-g trousers is deviating from the desired value. This is done by developing a detection algorithm which gives two kinds of alarm. One is given during minor deviations using a CUSUM test, and one is given at grave deviations, based on different conditions including residual, derivative and time. The thresholds, in which between the pressure should lie in a faultless system, are calculated from the g-load value. The thresholds are based upon given static guidelines for the pressure tolerance area and are modified in order to adapt to the estimated dynamics of the system. The values of the input signals, pressure and g-load, were taken from real flight sessions. The validation has been performed using both faultless and faulty flight sequences, with low false alarm rate and no missed detections. All together the detection system is considered to work well.

En viktig del av en nations säkerhetspolitiska ambition handlar om att skaffa sig handlingsutrymme. Detta görs genomen orkestrering av nationens olika maktmedel. På militärstrategisk nivå skapar en samordning av politisk målsättning,doktriner och resurser en samlad nettoeffekt, vilken utgör nationens möjliga militära strategi.Efter att det kalla kriget upphört har stora förändringar i den säkerhetspolitiska miljön för bland annat Sverige ägtrum. Sverige har därför förändrat sin säkerhetspolitiska utformning och Försvarsmakten och dess luftstridskrafter harföljt efter. Det svenska flygsystemet skall idag exempelvis kunna användas i av NATO eller EU ledda fredsframtvingandeoperationer. Det förband som Sverige anmält till EU: s registerförband benämns SwAFRAP JAS 39. Dettaförband skall vid en internationell operation nyttja flygplanet JAS 39A, ett flygsystem som ursprungligen är framtagetmot den gamla säkerhetspolitiska kontexten. Uppsatsens problem är följande: Klarar JAS 39 systemet, trots attdet ursprungligen är projekterat mot den gamla säkerhetspolitiska utformningen, att uppfylla de krav som den nyasäkerhetspolitiska utformningen ställer? Frågeställningen besvaras genom att de uppgifter ett flygsystem kan få viden internationell operation granskas via fem olika kriterier.De viktigaste slutsatserna är att JAS 39A i sin nuvarande skepnad har brister på flera områden. Bland annat saknassambandsmedel som är kompatibla med tänkta allierade. Dessutom finns brister hos VMS- och IFF-systemen. Devapensystem som är avsedda för markmålsbekämpning har i vissa fall brister då det gäller precision, förmåga tillgraderad verkan och allvädersförmåga. Då möjlighet till lufttankning saknas är räckvidden och uthålligheten begränsande.Detta kompenseras dock till viss del av möjligheten att bära extratankar. Systemet har dessutom vissa förmågorsom i den nya säkerhetspolitiska utformningen inte är efterfrågade. Systemet har dock mycket stor utvecklingspotentialoch möjligheten att anpassa systemet till den nya säkerhetspolitiska utformningen är troligen god. / Avdelning: ALB - Slutet Mag 3 C-uppsHylla: Upps. ChP 03-05

Karaktären på krig har genom historien förändrats. Andelen konventionella krig har de sista 25åren utgjort mindre än en tiondel av det totala antalet väpnade konflikter globalt. Ettsamlingsbegrepp som inkluderar bl.a. terrorism, uppror, terrorismbekämpning ochupprorsbekämpning är irregular warfare. De internationella insatser som svenska förband kankomma att utföra kommer till del att vara i konflikter som har formen av irregular warfare.Syftet med uppsatsen har varit att ur ett förmågeperspektiv undersöka vilken användbarhetJAS 39C/D-systemet kan anses ha vid insatser som har formen av irregular warfare och vadsom kan utvecklas för att höja användbarheten. För att uppnå syftet har en teoretiskkonstruktion och metod som grundats på affärsidésynsättet använts. Denna teori användsnormalt för att uppskatta effektiviteten i företag och organisationer. Med hjälp av dennateoretiska konstruktion och metod har JAS 39C/D-systemets användbarhet i irregular warfareanalyserats.Resultatet i uppsatsen visar att JAS 39C/D-systemet har god användbarhet i irregular warfare.JAS 39C/D-systemet kan bistå med de flesta av de förmågor som efterfrågas av stridsflygplani irregular warfare men det finns brister i form av begränsad vapenlast, kort aktionstid utanlufttankning samt avsaknad av länksysystem för flygplan och sensorer. Resurser i form avövningar och utbildning stöder till del de förmågor som efterfrågas. Under den formellaflygutbildningen bör mer utbildning som stöder de efterfrågade förmågorna och samverkansamt samövning med markofficerare i samma utbildningssteg införas. För att nå ochupprätthålla förmågan till lufttankning bör det satsas mer på resurser i form av utbildning ochövning. / The character of wars has changed throughout history. The proportion of conventional wars forthe last 25 years has constituted for less than a tenth of the total number of armed conflicts inthe world. A concept that includes, but is not limited to terrorism, insurgency, counterterrorismand counterinsurgency is irregular warfare. The combined military effort that Swedish unitsmay perform in the future will in part be in conflicts that have the form of irregular warfare.The purpose of this essay is to examine the utility of the JAS 39C/D system in irregularwarfare from a capability perspective and to see what can be developed in order to increase theutility. In order to achieve the purpose of the essay a theoretical structure and method based ona business concept called affärsidésynsättet has been used. This theory is normally used toestimate the effectiveness in companies and organisations. Using this theoretical structure andmethod an analyze of the JAS 39C/D system’s utility in irregular warfare has been made.The conclusion of the essay shows that the utility of the JAS 39C/D system in irregularwarfare is good. The JAS 39C/D system has most of the abilities requested from fighteraircraft in irregular warfare but there are deficiencies in form of meagre weapon load, shortloitering time without air-to-air refueling and lack of link-system for aeroplanes and sensors.Resources like exercises and education partly support the abilities requested. In the formalfighter pilot training more education supporting the requested abilities is needed.Collaboration and training with equal army officers should be introduced in the fighter pilottraining. In order to achieve and maintain the ability of air-to-air refueling more exercise andeducation is needed. / Avdelning: ALB - Slutet Mag 3 C-upps. Hylla: Upps. ChP 06-08