Diagnosis and Supervision of technical systems is used to detect  faults when they occur. To make a diagnosis, tests based on residuals can be used. Residuals are used to compare observations of  the system with a model of the system, to detect inconsistencies. There are often many different types of faults which affects the  state of the system. These states are modeled as fault modes. The  difference between fault modes are the presence of faults in the  model. For each fault mode a different set of model equations is  used to describe the behaviour of the real system. When doing fault  diagnosis in real time it is good, and sometimes vital, to be able to change fault mode of the model, when a fault suddenly occurs in the real system. If multiple faults can occur the number of  combinations of faults is often so big, even for relatively small  systems, that residuals for all fault modes can not be prepared. To  handle this problem, the residuals are to be generated when they are  needed. The main task in this thesis has been to investigate how residuals  can be automatically generated, given a fault mode with a  corresponding model. An algorithm has been developed and to verify  the algorithm a model of a satellite power system, called  ADAPT-Lite, has been used. The algorithm has been made in two versions. One is focusing on numerical calculations and the other is  allowing algebraical calculations. A numerical algorithm is preferred in an automatized process because  of generally shorter calculation times and the possibility to apply it to systems which can not be solved algebraically but the  algebraical algorithm gives slightly more accurate results in some  cases. / Diagnos och övervakning av tekniska system används för att upptäcka fel när de inträffar. För att ställa en diagnos kan tester baserade på residualer användas. Residualer används för att jämföra observationer av ett system med en model av system för att upptäcka inkonsistens. Det finns ofta många typer av fel som påverkar ett systems tillstånd.Dessa tillstånd modelleras med olika felmoder. För varje felmod används olika uppsättningar av modellekvationer för att beskriva systemets beteende. När diagnoser ska ställas i realtid är det ofta bra och ibland avgörande att kunna byta felmod när ett fel plötsligt inträffar i systemet. Om multipelfel kan inträffa blir antalet kombinationer av fel ofta så stort att residualekvationerna för alla felmoder inte kan förberedas. Detta gäller även för relativt små system. För att hantera problemet bör residualerna kunna genereras vid den tidpunkt då de behövs. Examensarbetets huvuduppgift handlar om att undersöka hur residualerna kan genereras automatiskt, givet en felmod och en modell. En algoritm har utvecklats och verifierats med en model av ett kraftsystem för en satellit, kallad ADAPT-Lite. Algoritmen har gjorts i två versioner. Den ena tillåts göra algebraiska beräkningar men den andra, i så storutsträckning som möjligt, tillåts endast göra numeriska beräkningar. En numerisk algoritm föredras i en automatiserad process p.g.a. generellt sett kortare beräkningstid och dess egenskap att kunna lösa vissa problem som inte kan lösas algebraiskt. Den algebraiska algoritmen har dock visats sig ge aningen noggrannare resultat i många fall.

Throughout recent years, legislations concerning emission levels for vehicles have become more restrictive and will be even more restrictive in the future. In the recent European environmental standards, EURO 4 (2006) and EURO 5 (2008), further requirements have been added on top of low emission demands. All heavy duty trucks have to be equipped with an OBD-system. Scania CV AB has today an existing OBD-system that consists of several tests. Typically, a test is designed to check if a signal is inside specified limits or thresholds. To improve the system, Scania CV AB and Vehicular Systems at Linköping University have developed a method to design diagnosis systems in an automatic way, implemented in a toolbox called DSAME. In this thesis, an automatic designed OBD-system has been created with DSAME and the corresponding parts in a manually designed OBD-system have been identified. The two systems have been compared. The result shows that both systems are equally at detecting faults but the automatic designed OBD-system is a lot better to isolate the faults than the existing OBD-system.

Software testing is a vital part of the software development process and is used for the purposes of quality assurance, reliability estimation and verification and validation. However, software testing is extremely costly and time consuming. For instance, prior research indicated that more than 50% of the software development cost is devoted to testing. Due to the increased use of the Unified Modeling Language (UML) and model driven architecture approach in systems analysis and design, Model-Based Testing has been discussed as a prominent solution for software testing to address the above problems. This study presents a methodology for determining the test path which can then be further used to determine the test case for Model-Based Testing. Three real-world cases are used to test the usability (including the concepts, application, and advantages) of the proposed methodology. With this approach, software errors can be found at the systems analysis and design stage and thereby reduce the cost of software testing and enhance the efficiency of system development.

Clustering is a technique used to partition unlabelled data into meaningful groups. This thesis will focus on the area of clustering called model-based clustering, where it is assumed that data arise from a finite number of subpopulations, each of which follows a known statistical distribution. The number of groups and shape of each group is unknown in advance, and thus one of the most challenging aspects of clustering is selecting these features. Cross-validation is a model selection technique which is often used in regression and classification, because it tends to choose models that predict well, and are not over-fit to the data. However, it has rarely been applied in a clustering framework. Herein, cross-validation is applied to select the number of groups and covariance structure within a family of Gaussian mixture models. Results are presented for both real and simulated data. / Ontario Graduate Scholarship Program

The concept of downsizing has proved to be a succesful method to improve engine efficiency. The engine key component is the turbocharging system that use excess energy in the exhaust gases to compress air into the cylinder. There are different types of supercharging systems, in the thesis a serial turbo system is modeled together with a complete six cylinder engine. A model-based controller is developed that regulates the intake pressure to a certain reference. The controller operates in modes that are defined by the engine operating point. To control the turbochargers it is necessary to have knowledge about the energy in the exhaust gases. A dynamic temperature model has therefore been analyzed, which has led to surprising results regarding the temperature measurements made in the test cells. This is analyzed and improvements are suggested.The engine model is validated and the system, including controller, is evaluated in certain simulations. The serial turbo concept is compared to a VGT turbo system, which gives a hint of the possible advantages of serial turbo charging. / Konceptet downsizing är bevisligen en mycket kapabel lösning för att höja en motors verkningsgrad. Nyckelkomponenten är turbosystemet som använder överskottsenergi i avgaserna för att komprimera in luft till cylindern. Det finns olika typer av turbosystem, i denna uppsats modelleras en seriell turbostruktur tillsammans med en komplett sexcylindrig motor. En modellbaserad regulator utvecklas för att reglera insugstrycket. Regulatorn arbetar i moder som definieras av motorns arbetspunkt. För att styra turboladdningen på ett bra sätt är det viktigt att ha vetskap om energin i motorns avgaser, varpå mer dynamik har införts i befintlig temperaturmodell. Temperaturmätningar har lett till förvånande och teoretiskt motstridiga resultat. Detta har undersökts och förslag på förbättringar tas fram.Motormodellen har validerats och systemet tillsammans med regulatorn har utvärderats i simuleringsexperiment. Det seriella turbosystemet jämförs med ett VGT-system, varpå potentiella fördelar hos en seriell dubbelturbo diskuteras.

With the need for greener powertrains every more present, automakers and part suppliers are lacking skill staff to fulfill design roles. It is estimated there are over 20 million lines of software code in vehicles today and many embedded controllers. The shortage of these engineers is compounded by the economic down-turn of 2008-2009, which resulted in massive 20% to 30% layoffs, reduced internships and reduction of programs designed to recruit new talent. To increase their workforce pool, automakers are working with universities and governments operate student competitions such as EcoCAR 2: Plugging into the Future, alongside traditional private/university collaborations. These programs present students with real-world engineering challenges and the opportunities to design/construction solutions. This also exposes students to the concepts of experiential learning. The objective of this thesis will be to discuss the design, construction and operation of a vehicle for a student design competition or research group at an educational institution. A process based on model based design will be undertaken, which allows for a majority of the vehicle???s design to be completed virtually prior to vehicle prototyping. In this work the model based design method is based on General Motor???s Vehicle Design Process. A project management plan is also proposed, which breaks down tasks into three technical areas (mechanical, electrical and controls) and allows for parallelization and reduced development time will also be proposed. Finally, the resources required to operate a vehicle design team will be defined. This includes the support needed from the University, physical space, software and hardware tools, safety considerations and human capital. Examples are drawn from 2013 Chevrolet Malibu converted to a plug-in hybrid vehicle with an ethanol engine and a battery pack was designed and built. This thesis will showcase the concepts mentioned above through examples from the University of Waterloo Alternative Fuels Team and its participation in international EcoCAR 2 vehicle development competition. The conclusion is that application of the concepts did result in the successful construction of an EcoCAR 2 vehicle. Generally projects that were successful were provided with sufficient technical information from suppliers and supported with past-experiences. Recommendations include: (i) working with suppliers who are familiar with academic environments (including working with students new to vehicle design), (ii) rigorous documentation of design for future designs; and (iii) close collaboration with industry experts to review designs, manufacturing, project management and budgets.

Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Vachtsevanos, George; Committee Member: Liang, Steven; Committee Member: Michaels, Thomas; Committee Member: Vela, Patricio; Committee Member: Wardi, Yorai.

Thesi supervisor: Cesare Tinelli. Includes bibliographic references (p. 214-220).

Cluster analysis is used to detect underlying group structure in data. Model-based clustering is the process of performing cluster analysis which involves the fitting of finite mixture models. However, parameter estimation in mixture model-based approaches to clustering is notoriously difficult. To this end, this thesis focuses on the development of evolutionary computation as an alternative technique for parameter estimation in mixture models. An evolutionary algorithm is proposed and illustrated on the well-established Gaussian mixture model with missing values. Next, the family of Gaussian parsimonious clustering models is considered, and an evolutionary algorithm is developed to estimate the parameters. Next, an evolutionary algorithm is developed for latent Gaussian mixture models and to facilitate the flexible clustering of high-dimensional data. For all models and families of models considered in this thesis, the proposed algorithms used for model-fitting and parameter estimation are presented and the performance illustrated using real and simulated data sets to assess the clustering ability of all models. This thesis concludes with a discussion and suggestions for future work. / Dissertation / Doctor of Philosophy (PhD)

Model-based development (MBD) is an increasingly used approach for the development of embedded control software, with Matlab Simulink/Stateflow as the widely accepted language. The adoption of this development paradigm is prevalent in many safety-critical domains, including the automotive industry. With an increasing reliance on software for controlling vehicle functionality and the yearly advent of new vehicle features, automotive models have been growing in size and complexity, causing them to become increasingly difficult to maintain, refactor, and test. Given the centrality of models in MBD, it is a requisite that they be maintained under well-defined and principled software development processes that use precise notation to document system requirements and behavioural design description. Tabular methods have long been used for defining decision-making logic in software, due to their concise and precise manner of communicating complex behaviour, so it is not surprising that they are finding increased use in automotive software models. Thus their presence in Simulink models is increasingly prominent in the implementation of complex behaviour in production code. As a result of the safety-critical nature of the automotive industry, as well as the increasing size and complexity of its models, reliable refactoring and simplification techniques for tabular expressions are becoming an important need for automotive companies. To address this need, this thesis presents a methodology for refactoring complex tabular designs to improve requirements traceability with a focus on Matlab Simulink/Stateflow and the MBD approach. A case study of industrial examples from an automotive partner are used to motivate the work and demonstrate the proposed methodology's effectiveness in reducing design size and complexity, while also increasing testability and requirements traceability. / Thesis / Master of Applied Science (MASc)