Control of a diesel engine equipped with Variable Geometry Turbine (VGT) and Exhaust Gas Recirculation (EGR) requires a multivariable control method. One problem is that the engine system is non-linear. Furthermore there are strong cross-connections between inputs and outputs and the inputs have alsoboundaries. To be able to manage these control problems, MPC has been used that is a multivariable method. The MPC-controller consists of an optimization problem and therefore MPC can find the optimum control signals in an easy way. Furthermore the boundaries of the control signals can be handled with by-conditions in the optimization. The disadvantage with MPC is that it requires a lot of amount of calculations and memory, which are important factors when a control system should be implemented. Therefore it has been chosen to compare MPC with PID, that is a common and simpler method. The results from this thesis are that MPC is a method that gives more optimal and faster control. Furthermore MPC can handle different control cases much better, without changing the settings. On the other hand PID requires considerable fewer amounts of calculations and memory. In one case that has been examined, MPC requires 40 times more amounts of calculations than PID. To be able to control a non-linear system, both MPC and PID must be implemented in several different working points. Furthermore decoupling must be used in the PID-controller to be able to manage cross-connections that seems to be a very important problem.

<p>Control of a diesel engine equipped with Variable Geometry Turbine (VGT) and Exhaust Gas Recirculation (EGR) requires a multivariable control method. One problem is that the engine system is non-linear. Furthermore there are strong cross-connections between inputs and outputs and the inputs have alsoboundaries. To be able to manage these control problems, MPC has been used that is a multivariable method. The MPC-controller consists of an optimization problem and therefore MPC can find the optimum control signals in an easy way. Furthermore the boundaries of the control signals can be handled with by-conditions in the optimization. The disadvantage with MPC is that it requires a lot of amount of calculations and memory, which are important factors when a control system should be implemented. Therefore it has been chosen to compare MPC with PID, that is a common and simpler method. </p><p>The results from this thesis are that MPC is a method that gives more optimal and faster control. Furthermore MPC can handle different control cases much better, without changing the settings. On the other hand PID requires considerable fewer amounts of calculations and memory. In one case that has been examined, MPC requires 40 times more amounts of calculations than PID. To be able to control a non-linear system, both MPC and PID must be implemented in several different working points. Furthermore decoupling must be used in the PID-controller to be able to manage cross-connections that seems to be a very important problem.</p>

<p>The engine of JAS 39 Gripen, RM12, has recently been equipped with a new flameholder and a new engine inlet. This change has caused an increased noise level from the engine when the afterburner is in use. The noise level reaches its peak when the afterburner is partially used. The problem is thought to be unstable combustion in the regions around the flameholder. A solution to the problem has been proposed by Volvo Aero. The idea is to modify the software in the engine control unit (FADEC) that changes the airflows in the engine. This master thesis implements the proposed changes and analyzes the effects of this implementation. The analysis is done by simulations of a model of the engine that Volvo Aero has created and implemented in MatrixX/SystemBuild. Simulations showed that it is possible to achieve the desired result by the software changes. Further the simulations showed some problems with stability for the engine when controlled by the modified control unit. This was solved by implementing a filter in the FADEC software.</p>

The engine of JAS 39 Gripen, RM12, has recently been equipped with a new flameholder and a new engine inlet. This change has caused an increased noise level from the engine when the afterburner is in use. The noise level reaches its peak when the afterburner is partially used. The problem is thought to be unstable combustion in the regions around the flameholder. A solution to the problem has been proposed by Volvo Aero. The idea is to modify the software in the engine control unit (FADEC) that changes the airflows in the engine. This master thesis implements the proposed changes and analyzes the effects of this implementation. The analysis is done by simulations of a model of the engine that Volvo Aero has created and implemented in MatrixX/SystemBuild. Simulations showed that it is possible to achieve the desired result by the software changes. Further the simulations showed some problems with stability for the engine when controlled by the modified control unit. This was solved by implementing a filter in the FADEC software.

Hail storms, with hail commonly near 50 mm in diameter that travel with storm wind sabove 25 m/s, cause damages of a large magnitude throughout the globe, with places like USA, Australia and India suffering the greatest. These damages have serious consequences, not least telecommunication products mounted in exposed places. Hail robustness is therefore important to test throughout a product development process, to reduce faulty products and maintenance costs. This thesis includes test rig concepts for hail impact testing and focuses on one final concept. The thesis includes a simulation model of the hail impact test rig, together with a physical implementation of the rig for comparison and validation. Additional experiments and statistical analysis is included to conclude on the accuracy and consistency with respect to realistic hail cases. The result shows that the simulation corresponds to the test rig. This physical implementation of the test rig is consistent and accurate for average sized hail projectiles, however varies more for hail projectiles corresponding to more severe storms. / Hagelstormar, med hagel omkring 50 mm i diameter och en vindhastighet på over 25 m/s, orsakar stora skador över hela världen, där USA, Australien och Indien är några av de mest utsatta platserna. Skadorna har stor påverkan, inte minst telecomprodukterna som är monterade på utsatta platser. Därav är det viktigt att testa produkter mot hagelkollisioner under produktutvecklingsprocessen, för att reducera antalet skadade produkter och kostnader. Detta examensarbete innehåller olika koncept på testriggar som simulerar hagel, med fokus på ett slutgiltigt koncept. Rapporten innehåller en simuleringsmodell av testriggen, samt en fysisk implementering av den för jämförelse och validering. Ytterliggare experiment och statistisk analys innefattas för att kunna dra slutsatser om riggens nogrannhetoch konsekventhet i föhållande till realistiska hagelstormar. Resultatet visar att simuleringen motsvarar testriggens beteende, vilket är önskvärt. Den fysiska implementationen av riggen ger ett noggrant och konsekvent resultat för medelstora hagelprojektiler, däremot fås större variationer för hagelprojektiler som förekommer i  starkare stormar.