The objective with this thesis is to build a Black-Box model of the tank pressurization system in JAS 39 Gripen. This model is intended to be used in an existing diagnosis system for the security control in the tank pressurization system. The tank pressurization system is a MIMO system. This makes the identification process more complicated when the best model is to be chosen. In this master's thesis the identification procedure for a MIMO system can be followed. Testing of the diagnosis system with the created Black-Box model shows that the model seems to be good enough. The diagnosis system takes the right decisions in the performed simulations. This shows that system identification might be a good alternative to physical modelling for a real-time model. The disadvantage with the Black-Box model is that it is less accurate in steady-state than the physical model used before is. The advantage is that it is faster than the physical model. The diagnosis system and the model developed in this thesis are not directly applicable on the real system today. The model has to be redesigned on the real system, this is also the case for the diagnosis system. The diagnosis system also has to be redesigned, so general flight cases, not only the security control can be supervised. However, experiences and choices like input and output signals, and choice of sample interval can be reused from this thesis when a new model might be developed.

<p>The objective with this thesis is to build a Black-Box model of the tank pressurization system in JAS 39 Gripen. This model is intended to be used in an existing diagnosis system for the security control in the tank pressurization system. The tank pressurization system is a MIMO system. This makes the identification process more complicated when the best model is to be chosen. In this master's thesis the identification procedure for a MIMO system can be followed. Testing of the diagnosis system with the created Black-Box model shows that the model seems to be good enough. The diagnosis system takes the right decisions in the performed simulations. This shows that system identification might be a good alternative to physical modelling for a real-time model. The disadvantage with the Black-Box model is that it is less accurate in steady-state than the physical model used before is. The advantage is that it is faster than the physical model. The diagnosis system and the model developed in this thesis are not directly applicable on the real system today. The model has to be redesigned on the real system, this is also the case for the diagnosis system. The diagnosis system also has to be redesigned, so general flight cases, not only the security control can be supervised. However, experiences and choices like input and output signals, and choice of sample interval can be reused from this thesis when a new model might be developed.</p>

This thesis is a result of the increased requirements on availability and costs of the aircraft Jas 39 Gripen. The work has been to specify demands and to find methods suitable for development of a decision support system for the fault isolation of the aircraft. The work has also been to implement the chosen method. Two different methods are presented and a detailed comparison is performed with the demands as a starting point. The chosen method handle multiple faults in O(N2)-time where N is the number of components. The implementation shows how all demands are fulfilled and how new tests can be added during execution. Since the thesis covers the development of a prototype no practical evaluation with compare of manually isolation is done.

The process of flying fighter jets naturally comes with tough environments and manoeu-vres where temperatures, pressures and forces all have a large impact on the aircraft. Part degeneration and general wear and tear greatly affects functionalities of the aircraft, and it is of importance to carefully monitor the well being of an aircraft in order to avoid catastrophic accidents. Therefore, this project aims to investigate various ways to improve anomaly detection of selected signals in the Gripen E fuel system. The methodology in this project was to compare collected flight data with generated data of a simulation model. The method was conducted for three selected signals with different properties, namely the transfer pump outlet pressure and flow, as well as the fuel mass in tank 2. A neural network was trained to generate predictions of the residual between measured and simulated flight data, together with a RandomForestRegressor to create a confidence interval of said signal. This made it possible to detect signal abnormalities when the gathered flight data heavily deviated from the generated machine learning algorithm predictions, thus alarming for anomalies. Investigated methods to improve anomaly detection includes feature selection, adding ar-tificial signals to facilitate machine learning algorithm training and filtering. A large part was also to see how an improved simulation model, and thus more accurate simulation data would affect the anomaly detection. A lot of effort was put into improving the simulation model, and investigating this area. In addition to this, the data balancing and features to balance the data on was revised. A significant challenge to tackle in this project was to map the modelling difficulties due to differences in signal properties. A by-productof improving the anomaly detection was that a general method was obtained to create a anomaly detection model of an arbitrarily chosen signal in the fuel system, regardless of the signal properties. Results show that the anomaly detection model was improved, with the main improvement area shown to be the choice of features. Improving the simulation model did not improve the anomaly detection in the transfer pump outlet pressure and flow, but it did however slightly facilitate anomaly detection of the fuel mass in tank 2 signal. It is also concluded that the signal properties can greatly affect the anomaly detection models, as accumulated effects in a signal can complicate anomaly detection. Remaining improvement areas such as filtering and addition of artificial signals can be helpful but needs to be looked into for each signal. It was also concluded that a stochastic behaviour was seen in the data balancing process, that could skew results if not handled properly. Over all the three selected signals, only one flight was misclassified as an anomaly, which can be seen as great results.

<p>External stores mounted on aircraft generate loads which need to be estimated before first takeoff. These loads can be measured in a wind tunnel but since the possible store configurations are basically endless, testing them all is neither economically feasible nor time efficient. Thus, scaling based on geometrical similarity is used. This can, however, be a crude method. Stores with similar geometrical properties can still behave in different ways due to aerodynamic interference caused by adjacent surfaces.</p><p>To improve the scaling performance, this work focuses on investigating two CFD codes, ADAPDT and Edge. The CFD simulations are used to derive the difference in aerodynamic coefficients, or the Δ-effect, between a reference store and the new untested store. The Δ-effect is then applied to an existing wind tunnel measurement of the reference store, yielding an estimation of the aerodynamic properties for the new store.</p><p>The results show that ADAPDT, using a coarse geometry representation, has large difficulties predicting the new store properties, even for a very simple store configuration on the aircraft. Therefore it is not suited to use as a scaling tool in its present condition. Edge on the other hand uses a more precise geometry representation and proves to deliver good estimations of the new store load behavior. Results are well balanced and mainly conservative. Some further work is needed to verify the performance but Edge is the recommended tool for scaling.</p><p> </p>

<p>Författaren till detta arbete har anledning att tro att piloter från olika flygsystem inom Flygvapnet känner olika stor grad av meningsfullhet med det arbete de utför. I detta arbete gör författaren en undersökning där han utifrån ett beteendevetenskapligt perspektiv försöker påvisa sådana skillnader mellan stridspiloter och transportflygpiloter. Samt vilka effekter dessa skillnader i så fall kan innebära för piloternas hälsa och motivation i såväl yrket som i livet i allmänhet. Författaren beskriver utifrån Aaron Antonovskys teori om känsla av sammanhang (KASAM) hur det går att förklara varför vissa människor är bättre rustade än andra för att klara av problematiska situationer eller svåra händelser. Vidare beskriver författaren även vikten av att individer känner en meningsfullhet i det arbete de utför och hur detta kan påverka deras vilja till att stanna kvar i det. Största delen av empirin till arbetet erhåller författaren genom en enkätundersökning bland piloter i Flygvapnet som flyger antingen JAS 39 Gripen eller C-130 Hercules. Resultatet av undersökningen är att författaren inte lyckas påvisa någon skillnad i känsla av sammanhang mellan de båda grupperna. De har utifrån detta resultat således likartade förutsättningar för att hantera motgångar och svåra situationer i livet. Författaren ser vidare en tendens till att transportflygpiloterna uppfattar sitt arbete som något mer meningsfullt än stridspiloterna, särskilt tydligt är detta i åldersintervallet 30-39 år. Författaren lyckas emellertid inte påvisa dessa skillnader som statistiskt signifikanta och utifrån uppmätt meningsfullhet med yrket drar författaren slutsatsen att de båda pilotgrupperna har likartade förutsättningar till att vilja stanna kvar inom sina respektive yrken.</p> / <p>The author of this work has reasons to believe that pilots from different systems within the Swedish air force experiences different degree of meaning with that work they carry out. In this essay the author does a survey where he on the basis of a behavior scientific perspective tries to identify such differences between fighter pilots and transport pilots. He also tries to describe what possible effects these differences, if they exist, could cause for the pilots' health and motivation. The author describes on the basis of Aaron Antonovskys theory about sense of coherence (SOC) how it is possible to explain why some people, better than other, manage to copewith difficult situations or threatening events. Furthermore the author describes the importance of feeling a purpose and meaningfulness with the work the pilots do and how this may affect their willingness to remain in their trade. The author has obtained most of the empirical material through a survey among pilots in the Swedish Air Force, flying either the JAS 39 Gripen or the C-130 Hercules. The result of the study is that the author is not able to detect any differences in sense of coherence (SOC) between the two groups of pilots. Based on this result they therefore seem to have similar abilities to handle adversities and difficult situations in life. The author also sees a tendency that cargo pilots experiences their work as something more meaningful than fighter pilots, this is particularly evident in the age 30-39 years. However, the author does not manage to prove these differences as statistically significant. Based on the study the author therefore draws the conclusionthat neither of the two different groups of pilots is more likely than the other to leave their profession due to lack of meaningfulness with what they are accomplishing.</p>

Författaren till detta arbete har anledning att tro att piloter från olika flygsystem inom Flygvapnet känner olika stor grad av meningsfullhet med det arbete de utför. I detta arbete gör författaren en undersökning där han utifrån ett beteendevetenskapligt perspektiv försöker påvisa sådana skillnader mellan stridspiloter och transportflygpiloter. Samt vilka effekter dessa skillnader i så fall kan innebära för piloternas hälsa och motivation i såväl yrket som i livet i allmänhet. Författaren beskriver utifrån Aaron Antonovskys teori om känsla av sammanhang (KASAM) hur det går att förklara varför vissa människor är bättre rustade än andra för att klara av problematiska situationer eller svåra händelser. Vidare beskriver författaren även vikten av att individer känner en meningsfullhet i det arbete de utför och hur detta kan påverka deras vilja till att stanna kvar i det. Största delen av empirin till arbetet erhåller författaren genom en enkätundersökning bland piloter i Flygvapnet som flyger antingen JAS 39 Gripen eller C-130 Hercules. Resultatet av undersökningen är att författaren inte lyckas påvisa någon skillnad i känsla av sammanhang mellan de båda grupperna. De har utifrån detta resultat således likartade förutsättningar för att hantera motgångar och svåra situationer i livet. Författaren ser vidare en tendens till att transportflygpiloterna uppfattar sitt arbete som något mer meningsfullt än stridspiloterna, särskilt tydligt är detta i åldersintervallet 30-39 år. Författaren lyckas emellertid inte påvisa dessa skillnader som statistiskt signifikanta och utifrån uppmätt meningsfullhet med yrket drar författaren slutsatsen att de båda pilotgrupperna har likartade förutsättningar till att vilja stanna kvar inom sina respektive yrken. / The author of this work has reasons to believe that pilots from different systems within the Swedish air force experiences different degree of meaning with that work they carry out. In this essay the author does a survey where he on the basis of a behavior scientific perspective tries to identify such differences between fighter pilots and transport pilots. He also tries to describe what possible effects these differences, if they exist, could cause for the pilots' health and motivation. The author describes on the basis of Aaron Antonovskys theory about sense of coherence (SOC) how it is possible to explain why some people, better than other, manage to copewith difficult situations or threatening events. Furthermore the author describes the importance of feeling a purpose and meaningfulness with the work the pilots do and how this may affect their willingness to remain in their trade. The author has obtained most of the empirical material through a survey among pilots in the Swedish Air Force, flying either the JAS 39 Gripen or the C-130 Hercules. The result of the study is that the author is not able to detect any differences in sense of coherence (SOC) between the two groups of pilots. Based on this result they therefore seem to have similar abilities to handle adversities and difficult situations in life. The author also sees a tendency that cargo pilots experiences their work as something more meaningful than fighter pilots, this is particularly evident in the age 30-39 years. However, the author does not manage to prove these differences as statistically significant. Based on the study the author therefore draws the conclusionthat neither of the two different groups of pilots is more likely than the other to leave their profession due to lack of meaningfulness with what they are accomplishing.

External stores mounted on aircraft generate loads which need to be estimated before first takeoff. These loads can be measured in a wind tunnel but since the possible store configurations are basically endless, testing them all is neither economically feasible nor time efficient. Thus, scaling based on geometrical similarity is used. This can, however, be a crude method. Stores with similar geometrical properties can still behave in different ways due to aerodynamic interference caused by adjacent surfaces. To improve the scaling performance, this work focuses on investigating two CFD codes, ADAPDT and Edge. The CFD simulations are used to derive the difference in aerodynamic coefficients, or the Δ-effect, between a reference store and the new untested store. The Δ-effect is then applied to an existing wind tunnel measurement of the reference store, yielding an estimation of the aerodynamic properties for the new store. The results show that ADAPDT, using a coarse geometry representation, has large difficulties predicting the new store properties, even for a very simple store configuration on the aircraft. Therefore it is not suited to use as a scaling tool in its present condition. Edge on the other hand uses a more precise geometry representation and proves to deliver good estimations of the new store load behavior. Results are well balanced and mainly conservative. Some further work is needed to verify the performance but Edge is the recommended tool for scaling.

När vi nu står inför en ominriktning i Försvarsmakten mot ett insatsförsvar kommer förband och organisationställas inför nya utmaningar och uppgifter. För flygvapnet kan detta ställa till en del problem i och medatt materielplanen är långsiktig och tiden från beslut om anskaffning till implementering av nya system oftaär lång. Detta är inte fallet med politiska målsättningar vilka kan vara mycket föränderliga och ändra inriktningfrån ett försvarsbeslut till ett annat. När den politiska inriktningen för Flygvapnets förmåga till internationellainsatser nu även innefattar förmågan till flygunderstöd till Nordic Battle group, har då Flygvapnetmed JAS 39C som verkanssystem möjlighet att genomföra direkt flygunderstöd i moderna internationellakonflikter?Syftet med denna uppsats har varit att analysera om JAS 39C, med tillhörande vapen-, sensor- och kommunikationssystem,uppfyller de krav som ställs på ett flygsystem vid genomförandet av DFU i en internationellinsats. Med stöd av ett teoretiskt ramverk bestående av teorier, doktrin och moderna erfarenheter harbåde de grundläggande förutsättningarna för ett effektivt genomförande av direkt flygunderstöd identifieratssamt ett specifikt analysinstrument arbetats fram. Detta analysinstrument har därefter använts för attanalysera JAS 39C förmåga till direkt flygunderstöd.JAS 39C bedöms efter genomförd analys att med gällande materialplan inneha goda förutsättningar attgenomföra direkt flygunderstöd redan 2008. Dess styrka är här förmågan till precisionsbekämpning ochden goda responsförmågan, dess svaghet avsaknaden av allväderskapacitet. Resultaten i uppsatsen visardessutom att de förutsättningar som ligger till grund för ett effektivt genomförande av direkt flygunderstödgår att återfinna under såväl moralrelaterade förutsättningar som konceptuella eller rent fysiska förutsättningar.Vid en lösning som endast fokuserat på att uppfylla de fysiska förutsättningarna är risken därförstor att den sammanlagda effekten och slagkraften i samband med genomförandet av direkt flygunderstödinte når önskad nivå. / Facing a transformation of the armed forces both individual units and the organization will be confrontedwith new tasks and challenges. For the air force this could cause some problems due to the fact that it oftentakes some time from decision to implementation of new weapons and technical systems. This is not thecase with political objectives; they can change from one defense decision to another. When the politicalaim and direction regarding the air force capacity for global operations now also includes the ability tosupport the Nordic Battle Group, do the air force and the JAS 39C have the right means to carry out CloseAir Support in modern international conflicts?The purpose of this essay is to analyze if JAS 39C with its weapon-, sensor-, and communication systemscomply with the modern demands on a fighter aircraft carrying out Close Air Support in international operations.With the support of an analytical framework containing theories, doctrines and modern experiencesboth the requirements that lay the foundation for an effective accomplishment of Close Air Supportand a specific analytical instrument has been identified. The analytical instrument was thereafter used toanalyze JAS 39C and its ability to carry out Close Air Support.The results of the analysis show that JAS 39C, technically and materially, in all likelihood will be able tocarry out Close air support as early as 2008. Its strength being the ability to carry out precision engagementstogether with a high responsiveness and its weakness consisting in the lack of all-weather capacity.The results furthermore indicates that the foundation for an effective accomplishment of Close Air Supportcan be found within both moral related pre-conditions as well as conceptual or purely physical preconditions.A solution only focused on fulfilling physical pre-conditions may therefore risk that the combinedeffect and the effectiveness of a future Close Air Support mission will not reach the desired level. / Avdelning: ALB - Slutet Mag 3 C-upps.Hylla: Upps. ChP 0406

Loads determination for external stores on fighter aircraft is an important task for manufacturers in ensuring the safe operation of their aircraft. Due to the large number of possible store combinations, wind tunnel tests – the primary approach to obtaining loads data – cannot be performed for all configurations. Instead, supplementary techniques to estimating loads are necessary. One approach is to use information from another store and adapt it, using so-called scaling methods, to the non-tested store. In this thesis, a scaling method combining the results of computational fluid dynamics (CFD) simulations, for both a non-tested and a reference store, with existing wind tunnel data for the reference store, is thoroughly examined for a number of different stores, angles of attack, sideslip angles and Mach numbers. The performance of the proposed scaling method is assessed in relation to currently used scaling methods, using non-parametric and multivariate statistics. The results show no definitive improvement in performance for the proposed scaling method over the current methods. Although the proposed method is slightly more conservative, considerable variability in the estimates and an increased time consumption for scaling leads the author to advise against using the proposed method for scaling aerodynamic loads on external stores. / Lastbestämning för yttre utrustning på stridsflygplan är en viktig uppgift för att tillverkarna ska kunna garantera säkerheten för sina flygplan. Då antalet möjliga utrustningskombinationer är mycket stort, kan inte vindtunneltester – normalt den främsta metoden för att erhålla lastdata – utföras för alla konfigurationer. Således behövs kompletterande metoder för att skatta laster. Ett alternativ är att använda data från en annan utrustning och anpassa den, med hjälp av så kallade skalningsmetoder, till den icke-testade utrustningen. I detta examensarbete behandlas en skalningsmetod som kombinerar resultaten från numeriska strömningsberäkningar – så kallade CFD-simuleringar – för både en testad och en icke-testad utrustning med befintliga vindtunneldata för den testade utrustningen. Metoden undersöks grundligt för ett antal olika utrustningar, anfallsvinklar, sidanblåsningsvinklar och Machtal. Prestandan hos den föreslagna skalningsmetoden utvärderas i relation till nu använda skalningsmetoder, baserat på icke-parametrisk och multivariat statistik. Resultaten visar inga definitiva förbättringar av prestanda för den föreslagna skalningsmetoden jämfört med de nuvarande metoderna. Även om den föreslagna metoden är något mer konservativ, så föranleder betydande variationer i skattningar och en ökad tidsåtgång för skalning författaren att avråda från att använda den föreslagna metoden för skalning av luftlaster på yttre utrustning.