826 resultados para Automobiles--Design and construction


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The Switched Reluctance technology is probably best suited for industrial low-speed or zerospeed applications where the power can be small but the torque or the force in linear movement cases might be relatively high. Because of its simple structure the SR-motor is an interesting alternative for low power applications where pneumatic or hydraulic linear drives are to be avoided. This study analyses the basic parts of an LSR-motor which are the two mover poles and one stator pole and which form the “basic pole pair” in linear-movement transversal-flux switchedreluctance motors. The static properties of the basic pole pair are modelled and the basic design rules are derived. The models developed are validated with experiments. A one-sided one-polepair transversal-flux switched-reluctance-linear-motor prototype is demonstrated and its static properties are measured. The modelling of the static properties is performed with FEM-calculations. Two-dimensional models are accurate enough to model the static key features for the basic dimensioning of LSRmotors. Three-dimensional models must be used in order to get the most accurate calculation results of the static traction force production. The developed dimensioning and modelling methods, which could be systematically validated by laboratory measurements, are the most significant contributions of this thesis.

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Tourism is one of the biggest industry branches with billions of tourists traveling every year around the world. Therefore, solutions providing tourist information have to be up to date with both changes in the industry and the world’s technological progress. The aim of this thesis is to present a design and a prototype of a tourist mobile service which is individual-oriented, cost-free for the end user, and secure. On the information providers’ side, the solution is implemented as a Webbased database. The end users access the information through a Bluetooth application on their mobile devices. The Bluetooth-based solution allows to avoid any costs for the end users, that is tourists. The study shows that, even with small data transfers, the tourists could save significantly when compared to possible roaming charges for data transfer. Also, the proposed mobile service is not intrusive, as it is provided through an application installed by tourists voluntarily on their mobile devices. Through design and implementation this work shows that it is possible to build a system which can be used to provide information services to tourists through mobile phones. The work achieved a successful ongoing synchronization between the client and the server databases. Implementation and usage were limited to smart phones only, as they provide better technological support for the solution having features like maps, GPS, Wi-Fi, Bluetooth and Databases. Moreover, the design of this system shows how Bluetooth technology can be used effectively as a means of communication while minimizing its shortcomings and risks, such as security, by bypassing Bluetooth server service discovery protocol (SDP) and connecting directly to the device. Apart from showing the design and implementation of the end-user costfree mobile information service, the results of this work also highlight the possible business opportunities to the provider of the service.

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The present research focuses on the study of how to design message and select media in advertising to generate customer’s purchase intention towards senior mobile phone in China. The message design concentrates mainly on message framing and fear appeals study while the media selection method is only based on direct matching. For exploring the main research question, the study utilized qualitative methodology. The data collection consisted of a pre-interview questionnaire, interviews, and three sets of experiments. The experiments were designed to test the selected 18 participants’ responses toward different emotional appeals and message framings. The findings illustrate participants’ understanding of senior mobile phone and their media usage habits. Moreover, positive message framing and emotional appeals in advertising are more effective. Gender differences in responding to emotional appeals were explored as well.

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Green IT is a term that covers various tasks and concepts that are related to reducing the environmental impact of IT. At enterprise level, Green IT has significant potential to generate sustainable cost savings: the total amount of devices is growing and electricity prices are rising. The lifecycle of a computer can be made more environmentally sustainable using Green IT, e.g. by using energy efficient components and by implementing device power management. The challenge using power management at enterprise level is how to measure and follow-up the impact of power management policies? During the thesis a power management feature was developed to a configuration management system. The feature can be used to automatically power down and power on PCs using a pre-defined schedule and to estimate the total power usage of devices. Measurements indicate that using the feature the device power consumption can be monitored quite precisely and the power consumption can be reduced, which generates electricity cost savings and reduces the environmental impact of IT.

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This thesis presents a design for an asynchronous interface to Robotiq adaptive gripper s-model. Designed interface is a communication layer that works on top of modbus layer. The design contains function definitions, finite state machine and exceptions. The design was not fully implemented but enough was so that it can be used. The implementation was done with c++ in linux environment. Additionally to the implementation a simple demo program was made to show the interface is used. Also grippers closing speed and force were measured. There is also a brief introduction into robotics and robot grasping.

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This master’s thesis mainly focuses on the design requirements of an Electric drive for Hybrid car application and its control strategy to achieve a wide speed range. It also emphasises how the control and performance requirements are transformed into its design variables. A parallel hybrid topology is considered where an IC engine and an electric drive share a common crank shaft. A permanent magnet synchronous machine (PMSM) is used as an electric drive machine. Performance requirements are converted into Machine design variables using the vector model of PMSM. Main dimensions of the machine are arrived using analytical approach and Finite Element Analysis (FEA) is used to verify the design and performance. Vector control algorithm was used to control the machine. The control algorithm was tested in a low power PMSM using an embedded controller. A prototype of 10 kW PMSM was built according to the design values. The prototype was tested in the laboratory using a high power converter. Tests were carried out to verify different operating modes. The results were in agreement with the calculations.

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Planar, large area, position sensitive silicon detectors are widely utilized in high energy physics research and in medical, computed tomography (CT). This thesis describes author's research work relating to development of such detector components. The key motivation and objective for the research work has been the development of novel, position sensitive detectors improving the performance of the instruments they are intended for. Silicon strip detectors are the key components of barrel-shaped tracking instruments which are typically the innermost structures of high energy physics experimental stations. Particle colliders such as the former LEP collider or present LHC produce particle collisions and the silicon strip detector based trackers locate the trajectories of particles emanating from such collisions. Medical CT has become a regular part of everyday medical care in all developed countries. CT scanning enables x-ray imaging of all parts of the human body with an outstanding structural resolution and contrast. Brain, chest and abdomen slice images with a resolution of 0.5 mm are possible and latest CT machines are able to image whole human heart between heart beats. The two application areas are presented shortly and the radiation detection properties of planar silicon detectors are discussed. Fabrication methods and preamplifier electronics of the planar detectors are presented. Designs of the developed, large area silicon detectors are presented and measurement results of the key operating parameters are discussed. Static and dynamic performance of the developed silicon strip detectors are shown to be very satisfactory for experimental physics applications. Results relating to the developed, novel CT detector chips are found to be very promising for further development and all key performance goals are met.

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Commercially available haptic interfaces are usable for many purposes. However, as generic devices they are not the most suitable for the control of heavy duty mobile working machines like mining machines, container handling equipment and excavators. Alternative mechanical constructions for a haptic controller are presented and analysed. A virtual reality environment (VRE) was built to test the proposed haptic controller mechanisms. Verification of an electric motor emulating a hydraulic pump in the electro-hydraulic system of a mobile working machine is carried out. A real-time simulator using multi-body-dynamics based software with hardware-in-loop (HIL) setup was used for the tests. Recommendations for further development of a haptic controller and emulator electric motor are given.

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Heli Kautonen's presentation in the LIBER Conference 27 June, 2013 in Munich, Germany.

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The aim of this master’s thesis was to specify a system requiring minimal configuration and providing maximal connectivity in the vein of Skype but for device management purposes. As peer-to-peer applications are pervasive and especially as Skype is known to provide this functionality, the research was focused on these technologies. The resulting specification was a hybrid of a tiered hierarchical network structure and a Kademlia based DHT. A prototype was produced as a proof-of-concept for the hierarchical topology, demonstrating that the specification was feasible.

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At present, permanent magnet synchronous generators (PMSGs) are of great interest. Since they do not have electrical excitation losses, the highly efficient, lightweight and compact PMSGs equipped with damper windings work perfectly when connected to a network. However, in island operation, the generator (or parallel generators) alone is responsible for the building up of the network and maintaining its voltage and reactive power level. Thus, in island operation, a PMSG faces very tight constraints, which are difficult to meet, because the flux produced by the permanent magnets (PMs) is constant and the voltage of the generator cannot be controlled. Traditional electrically excited synchronous generators (EESGs) can easily meet these constraints, because the field winding current is controllable. The main drawback of the conventional EESG is the relatively high excitation loss. This doctoral thesis presents a study of an alternative solution termed as a hybrid excitation synchronous generator (HESG). HESGs are a special class of electrical machines, where the total rotor current linkage is produced by the simultaneous action of two different excitation sources: the electrical and permanent magnet (PM) excitation. An overview of the existing HESGs is given. Several HESGs are introduced and compared with the conventional EESG from technical and economic points of view. In the study, the armature-reaction-compensated permanent magnet synchronous generator with alternated current linkages (ARC-PMSG with ACL) showed a better performance than the other options. Therefore, this machine type is studied in more detail. An electromagnetic design and a thermal analysis are presented. To verify the operation principle and the electromagnetic design, a down-sized prototype of 69 kVA apparent power was built. The experimental results are demonstrated and compared with the predicted ones. A prerequisite for an ARC-PMSG with ACL is an even number of pole pairs (p = 2, 4, 6, …) in the machine. Naturally, the HESG technology is not limited to even-pole-pair machines. However, the analysis of machines with p = 3, 5, 7, … becomes more complicated, especially if analytical tools are used, and is outside the scope of this thesis. The contribution of this study is to propose a solution where an ARC-PMSG replaces an EESG in electrical power generation while meeting all the requirements set for generators given for instance by ship classification societies, particularly as regards island operation. The maximum power level when applying the technology studied here is mainly limited by the economy of the machine. The larger the machine is, the smaller is the efficiency benefit. However, it seems that machines up to ten megawatts of power could benefit from the technology. However, in low-power applications, for instance in the 500 kW range, the efficiency increase can be significant.

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Ore sorting after crushing is an effective way to enhance the feed quality of a concentrator. Sorting by hand is the oldest way of concentrating minerals but it has become outdated because of low capacities. Older methods of sorting have also been difficult to use in large scale productions due to low capacities of sorters. Data transfer and processing and the speed of rejection mechanisms have been the bottlenecks for effective use of sorters. A fictive chalcopyrite ore body was created for this thesis. The properties of the ore were typical of chalcopyrite ores and economical limit was set for design. Concentrator capacity was determined by the size of ore body and the planned mine life. Two concentrator scenarios were compared, one with the sorting facility and the other without sorting. Comparison was made for quality and amount of feed, size of equipment and economics. Concentrator with sorting had lower investment and operational cost but also lower incomes due to the ore loss in sorting. Net cash flow, net present value and internal rate of interest were calculated for comparison of the two scenarios.

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In a just-in-time, assemble-to-order production environments the scheduling of material requirements and production tasks - even though difficult - is of paramount importance. Different enterprise resource planning solutions with master scheduling functionality have been created to ease this problem and work as expected unless there is a problem in the material flow. This case-based candidate’s thesis introduces a tool for Microsoft Dynamics AX multisite environment, that can be used by site managers and production coordinators to get an overview of the current open sales order base and prioritize production in the event of material shortouts to avoid part-deliveries.

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A web service is a software system that provides a machine-processable interface to the other machines over the network using different Internet protocols. They are being increasingly used in the industry in order to automate different tasks and offer services to a wider audience. The REST architectural style aims at producing scalable and extensible web services using technologies that play well with the existing tools and infrastructure of the web. It provides a uniform set of operation that can be used to invoke a CRUD interface (create, retrieve, update and delete) of a web service. The stateless behavior of the service interface requires that every request to a resource is independent of the previous ones facilitating scalability. Automated systems, e.g., hotel reservation systems, provide advanced scenarios for stateful services that require a certain sequence of requests that must be followed in order to fulfill the service goals. Designing and developing such services for advanced scenarios with REST constraints require rigorous approaches that are capable of creating web services that can be trusted for their behavior. Systems that can be trusted for their behavior can be termed as dependable systems. This thesis presents an integrated design, analysis and validation approach that facilitates the service developer to create dependable and stateful REST web services. The main contribution of this thesis is that we provide a novel model-driven methodology to design behavioral REST web service interfaces and their compositions. The behavioral interfaces provide information on what methods can be invoked on a service and the pre- and post-conditions of these methods. The methodology uses Unified Modeling Language (UML), as the modeling language, which has a wide user base and has mature tools that are continuously evolving. We have used UML class diagram and UML state machine diagram with additional design constraints to provide resource and behavioral models, respectively, for designing REST web service interfaces. These service design models serve as a specification document and the information presented in them have manifold applications. The service design models also contain information about the time and domain requirements of the service that can help in requirement traceability which is an important part of our approach. Requirement traceability helps in capturing faults in the design models and other elements of software development environment by tracing back and forth the unfulfilled requirements of the service. The information about service actors is also included in the design models which is required for authenticating the service requests by authorized actors since not all types of users have access to all the resources. In addition, following our design approach, the service developer can ensure that the designed web service interfaces will be REST compliant. The second contribution of this thesis is consistency analysis of the behavioral REST interfaces. To overcome the inconsistency problem and design errors in our service models, we have used semantic technologies. The REST interfaces are represented in web ontology language, OWL2, that can be part of the semantic web. These interfaces are used with OWL 2 reasoners to check unsatisfiable concepts which result in implementations that fail. This work is fully automated thanks to the implemented translation tool and the existing OWL 2 reasoners. The third contribution of this thesis is the verification and validation of REST web services. We have used model checking techniques with UPPAAL model checker for this purpose. The timed automata of UML based service design models are generated with our transformation tool that are verified for their basic characteristics like deadlock freedom, liveness, reachability and safety. The implementation of a web service is tested using a black-box testing approach. Test cases are generated from the UPPAAL timed automata and using the online testing tool, UPPAAL TRON, the service implementation is validated at runtime against its specifications. Requirement traceability is also addressed in our validation approach with which we can see what service goals are met and trace back the unfulfilled service goals to detect the faults in the design models. A final contribution of the thesis is an implementation of behavioral REST interfaces and service monitors from the service design models. The partial code generation tool creates code skeletons of REST web services with method pre and post-conditions. The preconditions of methods constrain the user to invoke the stateful REST service under the right conditions and the post condition constraint the service developer to implement the right functionality. The details of the methods can be manually inserted by the developer as required. We do not target complete automation because we focus only on the interface aspects of the web service. The applicability of the approach is demonstrated with a pedagogical example of a hotel room booking service and a relatively complex worked example of holiday booking service taken from the industrial context. The former example presents a simple explanation of the approach and the later worked example shows how stateful and timed web services offering complex scenarios and involving other web services can be constructed using our approach.

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This study will concentrate on Product Data Management (PDM) systems, and sheet metal design features and classification. In this thesis, PDM is seen as an individual system which handles all product-related data and information. The meaning of relevant data is to take the manufacturing process further with fewer errors. The features of sheet metals are giving more information and value to the designed models. The possibility of implementing PDM and sheet metal features recognition are the core of this study. Their integration should make the design process faster and manufacturing-friendly products easier to design. The triangulation method is the basis for this research. The sections of this triangle are: scientific literature review, interview using the Delphi method and the author’s experience and observations. The main key findings of this study are: (1) the area of focus in triangle (the triangle of three different point of views: business, information exchange and technical) depends on the person’s background and their role in the company, (2) the classification in the PDM system (and also in the CAD system) should be done using the materials, tools and machines that are in use in the company and (3) the design process has to be more effective because of the increase of industrial production, sheet metal blank production and the designer’s time spent on actual design and (4) because Design For Manufacture (DFM) integration can be done with CAD-programs, DFM integration with the PDM system should also be possible.