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>

In Scania’s single speed engines for industrial and marine use, the engine speed is controlled by a PI-controller. This controller is tuned independent of engine type and application. This brings certain disadvantages since the engines are used in a wide range of applications where the dynamics may differ. In this thesis, the possibility to tune the controller automatically for a specific engine installation has been investigated. The work shows that automatic tuning is possible. By performing an identification experiment on the engine, the parameters in a first order model describing the dynamics of the engine and the load aggregate are determined. The control parameters are then determined as functions of the model parameters. Measurements on a generator set show that the proposed method provides a controller which is able to follow changes in the reference value, and to compensate for load disturbances. / I Scania’s envarvsmotorer för industri- och marin-bruk regleras varvtalet av en PI-regulator. Denna regulator är inställd oberoende av motortyp och applikation. Detta medför vissa nackdelar då motorerna används i flera olika typer av applikationer där dynamiken kan variera. I detta arbete har det undersökts huruvida det är möjligt att automatiskt ställa in parametrarna i en PID-regulator för en enskild motorinstallation. Arbetet visar att automatisk inställning är möjlig. Genom att göra ett identifieringsexperiment på motorn bestäms parametrarna i en första ordningens modell som beskriver dynamiken för den aktuella konfigurationen av motor och belastande aggregat. Därefter bestäms regulatorparametrarna som funktion av modellparametrarna. Mätningar på ett generatoraggregat visar att man med hjälp av den föreslagna metoden erhåller en inställning av regulatorn som både klarar av att följa börvärdesförändringar och kompensera för laststörningar.

In this thesis, the design of a self balancing prototype bike with a reaction wheel as balancing mechanism will be investigated. Bikes are inherently unstable systems, that dynamically resemble an inverted pendulum at a stand still. Previous work has mostly been focused on keeping the balance through manipulating the steering input, and using state space modelling in order to balance the bike. In this project, a PID controller was implemented as a mean of control for the reaction wheel which was driven by a brushless DC motor. Different variations of Ziegler Nichols tuning methods were compared, and an alternative heuristic tuning method for the PID controller was also tested. The standard Ziegler Nichols and the alternative method yielded the best results. / I detta kandidatexamensarbete kommer designen av en självbalanserande prototyp cykel med ett reaktionshjul som balanseringsmekanism att undersökas. Cyklar är instabila system, som dynamiskt liknar en inverterad pendel när de är stationära. Tidigare arbeten har huvudsakligen fokuserat på att hålla balansen genom att elektroniskt manipulera styrinmatningen och använda modern regelteknik för att balansera cykeln. I det här projektet implementerades en PID-regulator som ett medel för att styra reaktionshjulet, driven av en borstlös likströmsmotor. Olika varianter av Ziegler Nichols-metoden och den alternativa metoden gav de bästa resultaten.

The aim of the thesis was to implement and compare control methods in a model of a main battle tank. Three controllers were implemented in a two axis gimbal model and their performances were compared. The comparisons were performed using step changes in the reference signal, frequency analysis of an oscillating reference signal and disturbances, and turret mass uncertainties. The results showed that the sliding mode controller had the best performance for both reference changes and disturbance attenuation. The PID controller had a better performance for the change in reference, compared to the model predictive controller, but a significantly worse disturbance attenuation. Due to model approximations, such as assuming ideal engines and noise reduction, the results likely show a better performance than what can be expected if applied on a real main battle tank. Therefore, the results show an upper limit of the stabilization performance of turret and barrel control and should only be used to compare the controllers. / Målet med uppsatsen var att implementera och jämföra reglermetoder för en teoretisk modell av en modern stridsvagn. Tre metoder implementerades i ett tvåaxligt gimbalsystem och deras prestanda utvärderades. Mer specifikt utvärderades regulatorernas respons för en referensändring, en referensstörning och osäkerheter i tornets massa och massfördelning. Utifrån dessa resultat jämfördes sedan reglermetoderna. Resultaten visade att sliding mode regulatorn hade bäst prestanda för både referensändring och referensstörningen när man tittar på frekvensanalys av mät- och processstörningar. PID-regulatorn hade en bättre prestanda än MPC-regulatorn för en referensändring men en sämre respons för en referensstö-rning. På grund av modellförenklingar som till exempel antaganden om ideala motorer och brusreduktion visar resultaten troligen en något bättre prestanda än vad som kan uppnås på en riktigt stridsvagn. Det medför att resultaten visar en övre gräns för vad styrsystemet för en stridsvagns torn- och eldrörsrotation kan uppnå.