1,770 research outputs found

    Machine Learning for Identification and Optimal Control of Advanced Automotive Engines.

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    The complexity of automotive engines continues to increase to meet increasing performance requirements such as high fuel economy and low emissions. The increased sensing capabilities associated with such systems generate a large volume of informative data. With advancements in computing technologies, predictive models of complex dynamic systems useful for diagnostics and controls can be developed using data based learning. Such models have a short development time and can serve as alternatives to traditional physics based modeling. In this thesis, the modeling and control problem of an advanced automotive engine, the homogeneous charge compression ignition (HCCI) engine, is addressed using data based learning techniques. Several frameworks including design of experiments for data generation, identification of HCCI combustion variables, modeling the HCCI operating envelope and model predictive control have been developed and analyzed. In addition, stable online learning algorithms for a general class of nonlinear systems have been developed using extreme learning machine (ELM) model structure.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/102392/1/vijai_1.pd

    Meta-heuristic algorithms in car engine design: a literature survey

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    Meta-heuristic algorithms are often inspired by natural phenomena, including the evolution of species in Darwinian natural selection theory, ant behaviors in biology, flock behaviors of some birds, and annealing in metallurgy. Due to their great potential in solving difficult optimization problems, meta-heuristic algorithms have found their way into automobile engine design. There are different optimization problems arising in different areas of car engine management including calibration, control system, fault diagnosis, and modeling. In this paper we review the state-of-the-art applications of different meta-heuristic algorithms in engine management systems. The review covers a wide range of research, including the application of meta-heuristic algorithms in engine calibration, optimizing engine control systems, engine fault diagnosis, and optimizing different parts of engines and modeling. The meta-heuristic algorithms reviewed in this paper include evolutionary algorithms, evolution strategy, evolutionary programming, genetic programming, differential evolution, estimation of distribution algorithm, ant colony optimization, particle swarm optimization, memetic algorithms, and artificial immune system

    Cascade Optimisation of Battery Electric Vehicle Powertrains

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    Motivated by challenges in the motor manufacturing industry, a solution to reduce computation time and improve minimisation performance in the context of optimisation of battery electric vehicle powertrain is presented. We propose a cascade optimisation method that takes advantage of two different vehicle models: the proprietary YASA MATLAB® vehicle model and a Python machine learning-based vehicle model derived from the proprietary model. Gearbox type, powertrain configuration and motor parameters are included as input variables to the objective function explored in this work while constraints related to acceleration time and top speed must be met. The combination of these two models in a constrained optimisation genetic algorithm managed to both reduce the amount of computation time required and achieve more optimal target values relating to minimising vehicle total cost than either the proprietary or machine learning model alone. The coarse-to-fine approach utilised in the cascade optimisation was proven to be mainly responsible for the improved optimisation result. By using the final population of the machine learning vehicle model optimisation as the initial population of the following simulation-based minimisation, the initial time-consuming search to produce a population satisfying all domain constraints was practically eliminated. The obtained results showed that the cascade optimisation was able to reduce the computation time by 53% and still achieve a minimisation value 14% lower when compared to the YASA Vehicle Model Optimisation

    Hierarchical feature extraction from spatiotemporal data for cyber-physical system analytics

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    With the advent of ubiquitous sensing, robust communication and advanced computation, data-driven modeling is increasingly becoming popular for many engineering problems. Eliminating difficulties of physics-based modeling, avoiding simplifying assumptions and ad hoc empirical models are significant among many advantages of data-driven approaches, especially for large-scale complex systems. While classical statistics and signal processing algorithms have been widely used by the engineering community, advanced machine learning techniques have not been sufficiently explored in this regard. This study summarizes various categories of machine learning tools that have been applied or may be a candidate for addressing engineering problems. While there are increasing number of machine learning algorithms, the main steps involved in applying such techniques to the problems consist in: data collection and pre-processing, feature extraction, model training and inference for decision-making. To support decision-making processes in many applications, hierarchical feature extraction is key. Among various feature extraction principles, recent studies emphasize hierarchical approaches of extracting salient features that is carried out at multiple abstraction levels from data. In this context, the focus of the dissertation is towards developing hierarchical feature extraction algorithms within the framework of machine learning in order to solve challenging cyber-physical problems in various domains such as electromechanical systems and agricultural systems. Furthermore, the feature extraction techniques are described using the spatial, temporal and spatiotemporal data types collected from the systems. The wide applicability of such features in solving some selected real-life domain problems are demonstrated throughout this study

    Research and Education in Computational Science and Engineering

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    Over the past two decades the field of computational science and engineering (CSE) has penetrated both basic and applied research in academia, industry, and laboratories to advance discovery, optimize systems, support decision-makers, and educate the scientific and engineering workforce. Informed by centuries of theory and experiment, CSE performs computational experiments to answer questions that neither theory nor experiment alone is equipped to answer. CSE provides scientists and engineers of all persuasions with algorithmic inventions and software systems that transcend disciplines and scales. Carried on a wave of digital technology, CSE brings the power of parallelism to bear on troves of data. Mathematics-based advanced computing has become a prevalent means of discovery and innovation in essentially all areas of science, engineering, technology, and society; and the CSE community is at the core of this transformation. However, a combination of disruptive developments---including the architectural complexity of extreme-scale computing, the data revolution that engulfs the planet, and the specialization required to follow the applications to new frontiers---is redefining the scope and reach of the CSE endeavor. This report describes the rapid expansion of CSE and the challenges to sustaining its bold advances. The report also presents strategies and directions for CSE research and education for the next decade.Comment: Major revision, to appear in SIAM Revie

    Activity Report: Automatic Control 2012

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    Development of a modular Knowledge-Discovery Framework based on Machine Learning for the interdisciplinary analysis of complex phenomena in the context of GDI combustion processes

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    Die physikalischen und chemischen Phänomene vor, während und nach der Verbrennung in Motoren mit Benzindirekteinspritzung (BDE) sind komplex und umfassen unterschiedliche Wechselwirkungen zwischen Flüssigkeiten, Gasen und der umgebenden Brennraumwand. In den letzten Jahren wurden verschiedene Simulationstools und Messtechniken entwickelt, um die an den Verbrennungsprozessen beteiligten Komponenten zu bewerten und zu optimieren. Die Möglichkeit, den gesamten Gestaltungsraum zu erkunden, ist jedoch durch den hohen Aufwand zur Generierung und zur Analyse der nichtlinearen und multidimensionalen Ergebnisse begrenzt. Das Ziel dieser Arbeit ist die Entwicklung und Validierung eines Datenanalysewerkzeugs zur Erkenntnisgewinnung. Im Rahmen dieser Arbeit wird der gesamte Prozess als auch das Werkzeug als "Knowledge-Discovery Framework" bezeichnet. Dieses Werkzeug soll in der Lage sein, die im BDE-Kontext erzeugten Daten durch Methoden des maschinellen Lernens zu analysieren. Anhand einer begrenzten Anzahl von Beobachtungen wird damit ermöglicht, die untersuchten Gestaltungsräume zu erkunden sowie Zusammenhänge in den Beobachtungen der komplexen Phänomene schneller zu entdecken. Damit können teure und zeitaufwendige Auswertungen durch schnelle und genaue Vorhersagen ersetzt werden. Nach der Einführung der wichtigsten Datenmerkmale im Bereich der BDE Anwendungen wird das Framework vorgestellt und seine modularen und interdisziplinären Eigenschaften dargestellt. Kern des Frameworks ist eine parameterfreie, schnelle und dynamische datenbasierte Modellauswahl für die BDE-typischen, heterogenen Datensätze. Das Potenzial dieses Ansatzes wird in der Analyse numerischer und experimenteller Untersuchungen an Düsen und Motoren gezeigt. Insbesondere werden die nichtlinearen Einflüsse der Auslegungsparameter auf Einström- und Sprayverhalten sowie auf Emissionen aus den Daten extrahiert. Darüber hinaus werden neue Designs, basierend auf Vorhersagen des maschinellen Lernens identifiziert, welche vordefinierte Ziele und Leistungen erfüllen können. Das extrahierte Wissen wird schließlich mit der Domänenexpertise validiert, wodurch das Potenzial und die Grenzen dieses neuartigen Ansatzes aufgezeigt werden

    Data driven low-bandwidth intelligent control of a jet engine combustor

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    This thesis introduces a low-bandwidth control architecture for navigating the input space of an un-modeled combustor system between desired operating conditions while avoiding regions of instability and blow-out. An experimental procedure is discussed for identifying regions of instability and gathering sufficient data to build a data-driven model of the system\u27s operating modes. Regions of instability and blow-out are identified experimentally and a data-driven operating point classifier is designed. This classifier acts as a map of the operating space of the combustor, indicating regions in which the flame is in a good or bad operating mode. A data-driven predictor is also designed that monitors the combustion process in real time and provides a prediction of what operating mode the flame will be in for the next measurement. A path planning algorithm is then discussed for planning an input trajectory from the current operating condition to the desired operating condition that avoids regions of instability or blow-out in the input space. An adaptive layer is incorporated into the path planning algorithm to ensure that the path planner can update its trajectory when new information about the operating space becomes available

    Development of a modular Knowledge-Discovery Framework based on Machine Learning for the interdisciplinary analysis of complex phenomena in the context of GDI combustion processes

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    In this work, a novel knowledge discovery framework able to analyze data produced in the Gasoline Direct Injection (GDI) context through machine learning is presented and validated. This approach is able to explore and exploit the investigated design spaces based on a limited number of observations, discovering and visualizing connections and correlations in complex phenomena. The extracted knowledge is then validated with domain expertise, revealing potential and limitations of this method
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