05 Fakultät Informatik, Elektrotechnik und Informationstechnik

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6

Browse

Filters

2012 - 20145

Settings

Institute: search.filters.UBSInstitut.Institut für Rechnergestützte IngenieursystemePublication Type: search.filters.UBSTyp.Abschlussarbeit (Master)

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    ItemOpen Access
    Development of procedures and evaluation strategies for novel field-effect transistor sensors
    (2012) Parker, Michael Lee
    In order to evaluate new types of sensors based on the field-effect transistor technology, a cost-effective measurement and control system is developed. Because some new types of transistor-based sensors are particularly prone to drift and noise, a measurement system is built around evaluating the effect of a biasing technique known as switched biasing, which has been shown to reduce drift under certain configurations. The result is an implementation of software and hardware that is both able to control a transistor with switched biasing, explore drift-reducing switched biasing configurations, and accurately measure its performance with relatively high precision. Pre-Filtering of the measured data coupled with a fast actuation of an analog-to-digital converter is realized and implemented on a FPGA in the form of a rate-adjustable CIC decimation filter, which increases the signal-to-noise ratio and reduces the required data-transfer rate. The measurement system is controlled internally by a microcontroller and is interfaced through a USB interfaces to a higher-level system, such as a computer running MATLAB, and allows for multiple measurement systems to be operated in parallel. Systematic errors related to limitations of measurement hardware such as offset, temperature and drift are evaluated and compensated for through calibration.
  • Thumbnail Image
    ItemOpen Access
    Rechnerunterstützte Problemformulierung in der Entwurfsoptimierung : ein internetgestützter Ansatz
    (2014) Straßer, Florian
    In industriellen Entwicklungsprozessen ist aufgrund von immer komplexeren Produkten Multidisziplinäre Entwurfsoptimierung ein wesentlicher Bestandteil geworden. Um Multidisziplinäre Entwurfsoptimierung anwenden zu können, muss das jeweilige Optimierungsproblem erst aufwändig in eine mathematische Form gebracht werden. Während Anwendungsgebiete und Berechnungsalgorithmen Multidisziplinärer Entwurfs¬optimierung breit erforscht sind, führt die Unterstützung dieses Problemformulierungsprozesses momentan noch ein Nischendasein. Die Aufgabe dieser Arbeit ist es, diesen Umformungsprozess von Optimierungsproblemen zu vereinfachen. Hierzu wurde das Tool Problem Formulator entwickelt, welches in der Form eines Expertensystems erstellt wurde. Für die Umsetzung wurde ein internetgestützter Ansatz gewählt, dieser ermöglicht den Problemformulierungsprozess über einen Web-Browser. Zur Umsetzung wurde das Google Web Toolkit (GWT) verwendet, welches durch Technologien des semantischen Webs in Form von OWL ergänzt wurde. Zur Problemmodellierung wurde ein modularer Ansatz gewählt, der durch Instanziierung und Verkettung von Modulen die Grundstruktur eines Problems definieren lässt. Die Wissensdatenbank ist in Form einer Ontologie in OWL modelliert. Die Problemformulierung durch den End¬benutzer erfolgt über eine eigens entwickelte und aus der Wissensdatenbank dynamisch erzeugte grafische Benutzeroberfläche. Zur Evaluierung der Funktionalität wurde erst ein Basismodulkatalog erstellt, um damit ausgewählte, in der Praxis relevante, Modellierungsprobleme umzusetzen.
  • Thumbnail Image
    ItemOpen Access
    Implementation of an optimized distance function for retrieval and similarity comparison of non-rotational parts
    (2013) Aguilera Diez, Javier
    In the recent decades, advances in design of 3D solid models have been obtained due to the novel software and computing developments in addition to innovative design possibilities by using Computer Aid Design (CAD) in new product design. One of the superior methods to optimize the design process of 3D shapes is reusing of existing knowledge to assist in the design of new parts. In this concept, a classification system makes use of this huge amount of existing knowledge available and possible for the design as well as for the manufacturing. The advantage of using these knowledge results in reducing time and cost in the design process of a part. To achieve this goal, the philosophy of Group Technology that aims to group and classify parts has been applied. As a well-known approach of Group Technology, the Opitz Code System has been selected for this project which classifies manufacturing features of rotational and non-rotational solid models generating a shape signature. This Thesis aims to analyze, develop and realize the non-rotational section of the Opitz Code. To recognize and extract the features of non-rotational parts, IGES format has been implemented. This format identifies the boundary representation of a shape and generates a file with all their values. For the similarity comparison, a new distance function to compare Opitz codes has been implemented. To conclude this research, a Graphic User Interface (GUI) has been implemented to manage properly the full developed system including the database.
  • Thumbnail Image
    ItemOpen Access
    Modeling of an automatic CAD-based feature recognition and retrieval system for group technology application
    (2014) Moskalenko, Stanislav
    In recent time, many researches have come up with new different approaches and means for Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) integration. Computer-Aided Process Planning (CAPP) is considered to be a bridge that connects these both technologies. CAPP may involve such an important technique as automatic feature extraction - a procedure that is engaged in process plans generation to be used in producing a designed part. Also in terms of CAD, the feature extraction procedure facilitates a cooperative design and process planning within the entire product development process. The main objective of the thesis is to present a new automatic feature extraction and classification system that is able to process mechanical rotational and non-rotational parts from the Opitz Code System point of view. The implemented system takes Standard for Exchange of Product data (STEP) - a neutral product representation format as input and extracts features of parts required for further manufacturing. The STEP format is used to provide geometrical and topological information about machining parts. A methodology to extract shape features was developed based on these geometrical and topological data. As output, the proposed system codes the extracted part features to Opitz Code System. CAD product files were taken from official manufacturers of mechanical parts in order to evaluate the developed system.
  • Thumbnail Image
    ItemOpen Access
    Conceptualization and implementation of a prototype for realistic simulation of vehicles
    (2013) Velandia Vega, John Alexander
    Daimler FleetBoard offers telematic services by means of a special hardware installed in customers' vehicles to collect and send data to the FleetBoard's Service Centre (FBSC) platform. FBSC is in charge of receiving, processing and storing data generated by vehicles. The quality assurance and testing department guarantees that the telematic services meet their purpose, and no failures exist in the system. In that way, software to simulate vehicles' behaviour is required to test the functionalities of FBSC. However, the problem rises since this software uses simulated data instead of real data. In addition, the process of creating routes for simulations is manual. Based on the mentioned problems, the objective of this thesis is to design, implement and evaluate a prototype as mechanism of importing routes generated by real vehicles to the simulator’s database, to emphasise on using real data for simulations. Additionally, the process of creating routes is optimized using Web Map Services to automate this process. Consequently, an evaluation of the prototypical implementation is considered to guarantee the proper operation of the prototype's layers: WEB GUI (supported by Java Server Faces), business logic and the persistence layer (fostered by Java Persistence API).