The purpose of this thesis is to examine and present the oportunities of solving control problems using Modelica. This is done by creating some demonstration examples with exercises. These examples should cover as many types of control problems as possible. The exercises are aimed for people with basic knowledge in modeling and automatic control engineering but with little or no knowledge in Modelica. There are different types of Modelica implementations and the ones used in this thesis are OpenModelica and MathModelica.

At working sites all around monotonic tasks are performed. If one were able to automatize these kinds of tasks there would be a large economical profit to collect. Volvo CE are in the process of developing an autonomous wheel loader, to perform these types of monotonic, uniform tasks. The project is intended to be performed mainly be thesis workers. This report is the eighth thesis in this project. Earlier work has made the loader able to see a pile using a laser scanner. The machine can also see and fill a hauler. The usage of the laser scanner can only be made while the loader is standing still. The aim of this thesis work has been to make the loader able to scan its environment while it is moving. To do this an inertial measurement unit has been used for keeping track of the scanners orientation during a scan. The work of this thesis has resulted in a working set-up on the machine, and a robust framework for future work.

A cars powertrain consists of everything that is needed for its propulsion. The components in the driveline that transfer the power from the engine to the driven wheels are not absolutely stiff, hence they will wind up due to the torque and act as torsion springs. If you suddenly demand a bigger torque by stepping on the accelerator pedal, a so called tip in manoeuvre, and that torque is acquired from the engine as quickly as possible, the driveline will not be able to transfer that fast torque change due to its weakness and as a result it will start to oscillate. These oscillations will be transferred to the driven wheels and make the car to accelerate jerkily which will be experienced as uncomfortable by the passengers. Furthermore, there is a backlash in the driveline that will make the weakness in the driveline even more excited than it should have been if the backlash did not existed. To avoid too big problems with these oscillations there is a control system that controls the demanded torque. This control system is today an open loop control system, i.e. a filtering of the demanded torque. As the cars computer power is increasing steadily there is an interest of investigating if it is possible to get a higher performance control system by using a more advanced, closed loop, model based control system. In this thesis such a control system is developed. First a model of the system is constructed; this model is used to design an observer that estimates the non measurable states in the driveline. The results show that this observer estimates these states fine on the basis of the available signals. The observer is the base for the driveline control system and simulations show that this control system is a considerable improvement compared to the control system used today. / En bils drivlina består av allt som behövs för dess framdrift. De komponenter i drivlinan som överför kraften från motorn till hjulen är inte absolut stela utan dessa elastiska kroppar kommer att deformeras då de utsätts för ett moment och fungera som torsionsfjädrar. Om man snabbt begär ett större moment genom att trampa på gasen, en så kallad tip-in manöver, och detta begärda moment läggs ut så snabbt som möjligt från motorn kommer inte de veka axlarna ”hinna med” vilket medför att axlarna kommer att börja oscillera. Dessa oscillationer kommer att överföras till de drivande hjulen och göra att bilen accelererar ryckigt vilket upplevs som obehagligt av passagerarna i bilen. Detsamma gäller om man plötsligt släpper gasen, en så kallad tip-out manöver. Det finns dessutom ett glapp i drivlinan som gör att vekheten i axeln exciteras ännu mer än vad den skulle ha gjort om glappet inte hade existerat. För att undvika alltför stora problem med dessa oscillationer har man en reglering som gör att man inte lägger på hela det begärda momentet på en gång. I dag fungerar denna reglering till största delen genom öppen styrning, det vill säga genom en filtrering av det begärda momentet. I takt med att datorkraften hela tiden ökar i bilar är man nu intresserad av att utreda i fall man kan lösa detta reglerproblem på ett bättre sätt genom en mer avancerad, sluten, modellbaserad reglering. Även i den nya regleringen vill man enbart använda sig av redan befintliga sensorer i bilen då det skulle bli för dyrt att sätta in någon extra sensor enbart för att få en bättre drivlinereglering. I denna uppsats utvecklas en sådan reglering. Först konstrueras en modell av drivlinan som används till att skapa en observatör som skattar de icke mätbara tillstånden i drivlinan. Resultaten visar på att denna observatör skattar de icke mätbara tillstånden på ett bra sätt utifrån de tillgängliga mätsignalerna. Denna observatör används sedan som grund för en reglering av drivlinan och i simuleringar visar sig denna reglering vara markant bättre än den som används idag.

The aim of this thesis is to develop the knowledge about nonlinear and/or adaptive solid fuel boiler control at Vattenfall Utveckling AB. The aim is also to make a study of implemented and published control strategies. A solid fuel boiler is a large-scale heat (and power) generating plant. The Idbäcken boiler studied in this work, is a one hundred MW furnace mainly fired with wood chips. The control system consists of several linear PID controllers working together, and the furnace is a nonlinear system. That, and the fact that the fuel-flow is not monitored, are the main reasons for the control problems. The system fluctuates periodically and the CO outlets sometimes rise high above the permitted level. There is little work done in the area of advanced boiler control, but some interesting approaches are described in scientific articles. MPC (Model Predictive Control), nonlinear system identification using ANN (Artificial Neural Network), fuzzy logic, Hµ loop shaping and MIMO (Multiple Input Multiple Output) PID tuning methods have been tested with good results. Both linear and nonlinear system identification is performed in the thesis. The linear models are able to explain about forty percent of the system behavior and the nonlinear models explain about sixty to eighty percent. The main result is that nonlinear models improve the performance and that there are considerable disturbances complicating the identification. Another identification issue was the feedback during the data collection.

I fumingverket på Rönnskärsverken utvinns zinkklinker ur slaggen från elugnen. En annan råvara är stålverksstoft. I fumingugnen omvandlas smältans zink- och blyinnehåll till metallånga som oxideras till ett stoft. Stoftet renas i en klinkerugn. Slutprodukten, zinkklinker, som består av 70 - 75 % zink, exporteras till zinksmältverket Norzink i Norge. Klinkerugnen är ett väldigt långsamt system med stegsvarstider i storleksordningen en timme vilket gör den svårstyrd och det resulterar i störningar och stilleståndstid med låg produktion och låg kvalitet på klinkern. För att lösa detta problem testas automatisk reglering i detta arbete. Två processmodeller tas fram för simulering och reglerdesign och tre regulatorer har utvecklats i simulering. Två av dessa testas på den faktiska processen. Vidare har ett ramverk för snabb utveckling och testning av regulatorer utvecklats. En C++-klass för kommunikation via DDE-gränssnittet mellan regulator och operatörsgränssnittet har också konstruerats. / In the fuming plant at Rönnskärsverken smelter, zinc clinker is xtracted from slags and steel mill dust. In the fuming furnace, zinc and lead are vapourised by coal injection. The reoxidised metal dust is further refined at the clinker plant to obtain a product that is low in halogenes. Zinc clinker, which contains approximately 70 - 75 % zinc, is exported to the Norzink zinc smelter in Norway. The refinement takes place in an industrial kiln. The kiln is a very slow system and therefore difficult to control which results in disturbances and dead time. This causes low production rate and poor quality in the clinker. In order to cope with this, automatic control is tested in this thesis. Two process models have been built for simulation and control design and three controllers have been evaluated in simulation. Two of the developed controllers are tested on the actual process. A framework for fast controller prototyping has also been developed. A C++-class för communication using the DDE interface between controller and the operator user interface has also been implemented.

A modern fighter aircraft is exposed to very different flight conditions and must despite that perform infallibly in every single situation. Several variables like center of gravity, speed, altitude and weight vary during a standard mission flight or between flights. For the aircraft to be able to perform effectively, superior manoeuvrability is vital. Hence it is of great importance that the flight control system is capable to cope with these different variations. In the 1960s professor Isaac Horowitz presented the method Quantitative feedback theory (QFT) which is a method whose aim is to manage system variations. The method can be useful in the construction of the control system for a fighter aircraft. QFT is a frequency based method whose main objective is to shape the open loop gain in a Nicholschart to meet the required closed loop demands. A prefilter is then applied to achieve correct reference tracking. This thesis is divided into two parts, where the first part presents the method QFT for both the SISO-systems and for the MIMO-systems. For the MIMOsystems several design techniques are presented, the chapter also includes a method on the implementation of state feedback. Furthermore statements of how nonlinear and unstable systems are handled with the QFT is included. The second part of the thesis presents the design of a control system for an unstable fighter aircraft. The design is constructed for the SISO longitudinal dynamics as well as for the MIMO lateral dynamics, where the design must be robust against variations in speed, altitude and center of gravity. The flight control system that is implemented meets almost all requirements and gives good preformance and this is achieved with only a few regulators. Proposals of possible solutions to those requirements note yet reached are discusssed.

Detta examensarbete är en del av SNOD-projektet vid Totalförsvarets Forskningsinstitut (FOI), vars syfte är att utveckla ett sensorsystem med infraröda- och videosensorer och integrerat navigationssystem. Sensorsystemet är placerat i en kameragimbal och kan användas på rörliga plattformar, t ex UAV:er, för övervakning och rekognoscering. Gimbalen är till för att möjliggöra inriktning av sensorerna i önskad riktning. Detta examensarbete behandlar en metod för inmätning av målkoordinater från den rörliga plattformen, det s k QWIP/MASP-systemet. Detta efterliknar ett UAV-system. Metoden för inmätning baseras på ett extended information filter där målkoordinaterna filtreras fram. Mätningarna bygger på data från en bildbaserad målföljare med på IR- och videodata. För att förbättra inmätningen har en metod för planering av plattformens rörelsebana tagits fram. Denna metod bygger en referensbana för plattformen som maximerar informationen i informationsfiltret. Metoderna har utvecklats för implementering i den aktuella sensorplattformen, QWIP/MASP-systemet. För att övervaka och styra denna plattform har ett grafiskt användargränssnitt tagits fram för operatörsstöd. / This thesis is a part of the SNOD project at Swedish Defence Research Agency (FOI), which aims at developing a sensor system consisting of infrared and video sensors and an integrated navigation system. The sensor system is placed in a camera gimbal and will be used on moving platforms, e.g. UAVs, for surveillance and reconnaissance. The gimbal is a device that makes it possible for sensors to be pointed in a desired direction. In this thesis a method for estimating target position using a moving platform is discussed. This method is based on the extended information filter, where bearingonly measurements are given by infrared and video images processed through a target tracker. Tests and evaluations are done with data from the QWIP/MASP-system, which is an UAV surrogate developed at FOI. To improve target position estimation, a path planning method using information theory has been developed. This method is based on maximizing the expected information of the information filter. These methods have been developed for implementation in the QWIP/MASP-system. A user interface for this system has also been developed to support the operator.

<p>Abstract</p><p>This work was assigned by a technological company that manufactures gas detectors in which the sensor signal is processed using digital filters. These filters have been developed by a consultancy firm which converted previously used analog filters to digital filters. The purpose of this work has been to analyse inadequate, and sometimes erroneous, documentation from the project in order to provide the company with know-how and tools for further improvement of their products. The work has been done using the simulation software COMSOL which was bought solely for the project. Analysis showed serious flaws as well as pure errors in the consultant’s documentation. By sorting out and documenting the actual functionality it has been possible to propose further improvements. One such possible improvement is described in the report.</p>

<p>AIMS AB is a Swedish company that develops and sells inertial sensor systems. A new product is under research which basically is an aided inertial navigation system where unwanted drift is eliminated. This can be done by integrating a GPS reciever into the system and fuse measurement data from GPS and IMU. Such a product is useful in racing, where engineers always are searching for the optimal performance and the shortest lap times. Today the only feedback the engineers and mechanics get from their work is the driver’s comments and lap times. It would be of great help if it was possible to see the behaviour of the car directly in technical terms. The focus of this master thesis is fusing a GPS receiver and an IMU using an Extended Kalman Filter (EKF). The main task of the EKF is to estimate the errors of the intertial measurements and correct the measurements to eliminate drift in velocity and position. To verify the system, data collection was done togheter with the team G2 Racing and Tony Ring. The measurements were done in Tony’s Ferrari F430 Pista during two days at the Paul Ricard circuit in southern France. From the results possibilites to further estimate interesting entities were evaluated.</p> / <p>AIMS AB är ett företag som tillverkar och säljer olika typer av tröghetsnavigeringssystem. En ny produkt med ett tröghetsnavigeringssystem stöttat av GPS är under utveckling. Med sensorfusion kan GPS- och IMU-mätningar integreras genom användning av ett Extended Kalman Filter (EKF). Ett sådant system kan komma till användning inom racing där strävan efter optimal prestanda och korta varvtider är stor. Den information ingenjörerna får om bilens beteende är ofta enbart förarens kommentarer. Förarens beskrivning kan ofta vara svår att översätta till tekniska termer som behövs för att enkelt justera inställningar och nå önskade egenskaper. Det skulle vara till stor hjälp om ingenjörerna direkt fick tillgång till teknisk information om fordonets beteende. I detta examensarbete ligger fokus på sensorfusion av GPS- och IMU-mätningar genom användning av ett Extended Kalman Filter (EKF). Huvuduppgiften för kalmanfiltret är att skatta fel i mätningar av accelerationer och vinkelhastigheter så att korrigering för dessa kan göras och därmed drift i position elimineras. För verifiering av systemet har datainsamling utförts tillsammans med teamet G2 Racing och Tony Ring. Mätningnarna är gjorda i Tonys Ferrari F430 Pista under två dagar på banan Paul Ricard i södra Frankrike. Ur resultatet undersöks även möjligheterna till vidare skattning av intressanta data som kan vara till hjälp för ingenjörerna i ett racingteam.</p>

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 251-256). Also available on the Internet.