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Emulation of Recoil in Pyrotechnic Countermeasure Dispenser System / Emulation of Recoil in Pyrotechnic Countermeasure Dispenser SystemLindgren, Ebba January 2020 (has links)
Developing countermeasures dispenser systems requires many and careful tests. When it comes to testing products with pyrotechnics, testing can often be very complicated and expensive. This might lead to no testing at all due to time or resource shortages. Products to be used in the military requires further testing and even more thorough reviews to meet the strict demands placed on the products. In order to enable more tests of pyrotechnic flares in the countermeasures industry, this degree project aims to increase the ability to perform tests without the need for pyrotechnic means. This was done by designing, constructing and optimizing a recoil emulator, an apparatus that imitates the force-time curve obtained by pyrotechnic flares without the need of pyrotechnic means. The construction of the recoil emulator was conducted at a department that develops countermeasure systems at Saab Surveillance in Järfälla. The apparatus aims to be used in the future for testing and verification of product series of countermeasures dispenser systems. The design of the apparatus was based on a test result provided by a flare manufacturer of an arbitrarily chosen flare, typical in the countermeasures industry. Based on the provided test result, three measures were chosen that together describe the fundamental and essential characteristic parts of the recoil motion behavior of pyrotechnic flares. These three measures are in the thesis called \textit{recoil measure} and defined as the Peak Recoil, the Impulse, and the Peak-Width. To be able to verify the recoil emulator, the three recoil measures were implemented in an error model, which was based on the squares of error. In order to make the emulator imitate the desired recoil motion behavior as pleasant as possible, the error model was implemented in an optimization model. By minimizing the error of data points from each of the recoil measures obtained from the real test provided by the manufacturer with results obtained from the recoil emulator, the emulator was verified and optimized accordingly. Results showed that the selected design of the recoil emulator resulted in a force-time curve that principally mimics the curve given by the real tests. The conclusion from the project was, therefore, that it is possible perform tests on countermeasures systems without pyrotechnics when considering the impact of recoil. Further development of this thesis could be to improve the construction of the recoil emulator and perform more research on flares and damping materials. Other future work could be to implement the emulator in existing test and validation processes at companies within the countermeasure industry. / Att utveckla motmedelsprodukter kräver många och noga utförda tester. När det kommer till testning av produkter med pyroteknik kan testerna ofta bli väldigt komplicerade och dyra eller inte göras alls på grund av tid- eller resursbrist. Produkter som ska användas inom militären kräver i många fall ytterligare tester och ännu noggrannare genomgångar för att kunna klara av de tuffa krav som sätts på produkterna. Den här avhandlingen syftade till att möjliggöra fler tester för pyrotekniska medel inom motmedelsindustrin. Detta har gjorts genom konstruktion, design och optimering av en rekylemulator; en apparat som immiterar den kraft-tid kurva som erhålls av pyrotekniska facklor, utan att använda pyrotekniska medel. Konstruktionen och utvecklandet av rekylemulatorn gjordes på uppdrag av en avdelning som utvecklar motmedelssytem på Saab Surveillance i Järfälla. Syftet med emulatorn är att använda den i framtiden vid testning och verifierering av produktserier av motmedelssystem. Designen av apparaten utgick från testresultat som tillhandahållits av en fackeltillverkare av en godtyckligt vald pyroteknisk fackla, vanlig inom motmedelsindustrin. Utifrån testresultaten togs tre mått ut som tillsammans beskriver fundamentala och viktiga karaktäristiska delar av rekylkraftsbeteendet hos pyrotekniska facklor. Dessa tre mått kallas \textit{rekylkraftsmått} och definieras som rekylpeaken, impulsen, samt peakbredden. För att kunna verifiera rekylemulatorn implementerades dessa tre rekylkraftsmått i en felmodell, som baserades på det kvadratiska felet. För att få emulatorn att imitera det önskade rekylkraftsbeteendet så bra som möjligt implementerades en felmodellen i en optimeringsmodell. Genom att minimera felet av datapunkter från varje rekylkraftsmått som erhålls från resultatet av både det verkliga testet, tillhandahållna av tillverkaren, samt med resultat erhållna från rekylemulatoren kunde emulatorns valideras.
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