• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 23
  • 12
  • 11
  • Tagged with
  • 46
  • 10
  • 8
  • 8
  • 8
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Simulering av pneumatisk sänkborrhammare

Ek, Fredrik January 2003 (has links)
<p>Denna rapport utgör dokumentationen av ett examensarbete utfört på Atlas Copco Secoroc i Fagersta under handledning av Maskinkonstruktions före detta universitetslektor Håkan Wettergren och Fluid & Mekaniksystems professor Karl-Erik Rydberg och på Atlas Copco Secoroc konstruktör Risto Wisakanto, avdelningschef Thomas Greijer, båda avdelning DTH, samt Secorocs utvecklingschef Lars Holmgren.   Arbetet syftar till att utveckla en simuleringsmodell vilken ska användas vid utveckling av pneumatiska sänkborrmaskiner. Målsättningen var att göra en så bra modell som möjligt, en modell som skulle kunna användas vid utveckling av nya sänkborrmaskiner, och att stegvis förfina en i grunden enkel modell. Första modellen var dock lite för enkel och baserad på teori för slutna system så den gick inte bygga vidare på utan det var enklare att göra en helt ny modell baserad på teori för öppna system. Det var dock inte förgäves att bygga den första modellen utan de geometriska villkoren som använts i den enkla modellen kunde återanvändas i den mer avancerade som tack vare detta relativt snabbt kunde skapas.  Den mer avancerade modellen ger värden som stämmer mycket bra överens med mätresultat vid höga tryck, i detta fall 16 bar. Att modellen inte stämmer överens så bra vid låga tryck kan bero på flera saker, naturligtvis på att faktorer som försummats kanske har stor inverkan vid låga tryck eller att mätvärdena helt enkelt är fel. Maskinen går inte stabilt 6 respektive 10,5 bar utan gör det först vid 16 bar vilket gör att det är relevant att jämföra simulerade värden med mätvärden först vid 16 bar, en annan felkälla kan vara att givarna inte hänger med i det snabba förloppet samt att de inte är helt exakta (Greijer, 2002).     Kartläggning av en befintlig maskins geometrier, studier av termodynamiska lagar samt provborrningsresultat har legat till grund för modellen.</p> / <p>This report constitutes the documentation of a master thesis performed at Atlas Copco Secoroc in Fagersta under supervision by the division of Machine Design’s former lecturer (PhD) Håkan Wettergren and the division of Fluid & Mechanical Engineering System’s professor (PhD) Karl-Erik Rydberg and at Atlas Copco Secoroc design engineer Risto Wisakanto, head of department Thomas Greijer, both department DTH, and Secorocs head of research and development Lars Holmgren. The purpose with this work is to develop a simulation model which will be used at development of pneumatic down-the-hole hammers.  Mapping of an existing machines geometry, studies of thermodynamic laws and test results is the basic sources used during development of this model.</p>
32

Identifikace parametrů matematického modelu pneumatik / Identification of tire model parameters

Olišar, Petr January 2020 (has links)
The main goal of this thesis is to obtain lateral parameters of the Magic Formula tire model of a tire commonly used in Formula Student competition. Both the author and the supervisor of the thesis know the tire name and its specification, but the research company that did the tire testing and provided me with the date prohibits sharing this of data publicly, so the tire designation is not mentioned in this thesis. The first chapter covers main theoretical facts related to a tire, briefly describes some of the tire models and shows possibilities how to determine tire characteristics that are used in a tire model. The thesis describes how to process raw tire data measured during a laboratory experiment using scripts created in Matlab software. The inputs variables are slip angle, lateral force, normal force and inclination angle. Raw data are splitted into parts, main coefficients of the Magic formula model (B, C, D, E, Sh, Sv) are calculated and subsequently the lateral parameters are obtained using least square method to fit parameters into the measured data. The works gives two main outcomes. The first output is a set of Matlab scripts that can be used to determine lateral parameters of any tire that has the same input data format as presented. A TIR file of the Formula Student tire in case of lateral slip is the second result of the work. This can be used for vehicle dynamics simulation of Formula Student racing car. The thesis also offers a comparison between parameters, which I calculated, and those gained thanks to Optimum Tire software by Calspan research company. Additionally the work shows the effect of load and inclination angle on lateral force.
33

Zkušební komora pro ozónovou degradaci pneumatik / Test cell for ozone degradation of tires

Píza, Tomáš January 2008 (has links)
This diploma thesis is occupy by assesment optimum method straining of tyres and then constructional concept of test cell for ozone degradation of rubber tyres with sizes from 13” to 15”. The final aim of this diploma thesis is construction of test cell which is based on choice of optimum method straining of tyres. The next output of this diploma thesis is concept of unit for ozone degaradation of tyres.
34

Predictive maintenance with a minimum of sensors using pneumatic clamps as an example

Gauchel, Wolfgang, Streichert, Thilo, Wilhelm, Yannick 25 June 2020 (has links)
In standard pneumatics, the available signals for data analytics are very limited. As a rule, no continuous status information is available. Usually only the reaching of the end position is indicated - by means of a digital signal of a proximity sensor. This paper examines whether these limited data can be used to derive usable and useful information for predictive maintenance. Pneumatic clamps in bodyin- white construction were chosen as application example. The paper describes a continuous run to investigate the basic feasibility of predictibility. In the following chapters, possibilities for error classification are discussed. Finally, the implementation of the findings in a field test is described.
35

Pneumatics and Industrie 4.0 - opportunity or contradiction?

Post, Peter 26 June 2020 (has links)
Modern industrial production processes are increasingly characterized by digital solutions in order to continuously increase their efficiency while taking sustainability aspects into account. Pneumatic components and systems have been and will continue to be an essential part of modern production plants and must face the special challenges posed by digitalization [... aus dem Text]
36

Energy efficiency in pneumatics with the 'Air Saving Box': the revolutionary plug & play solution from SMC

Heitmann, Mario, Rein, Ferdinand 26 June 2020 (has links)
For many companies, energy efficiency starts with production. For this reason, special consideration must be given to the production operation as a whole as well as its sub-areas. The strict legal requirements, as well as the companies`green policies which are defined as a result of these, create complex challenges, which SMC meets with expertise and passion as a manufacturer, partner and solution provider in electric and pneumatic automation technology. On the basis of an actual customer requirement, SMC Germany has developed an innovation in the field of pneumatic energy efficiency: The Air Saving Circuit for double acting pneumatic cylinders , under the working title of Air Saving Box . The underlying idea and focus of the solution was to make good use of the compressed air generated in existing cylinders, instead of simply allowing it to go to waste. The Air Saving Box enables significant energy savings in production. Based on this customised solution, SMC has also developed an industry-independent concept that can also be integrated into existing applications.
37

A Digital Test Bench for Pneumatic Brakes / En digital provbänk för tryckluftsbromsar

Schick, Bastian January 2021 (has links)
This master’s thesis covers the structuring and implementation of a digital testbench for the air brake system of freight trains. The test bench will serveto further improve the existing brake models at Transrail Sweden AB. Theseare used for the optimised calculation of train speed profiles by the DriverAdvisory System CATO. This work is based on the research of the technicalbackground, as well as the methodical approach to physical modelling anda modular implementation of the test bench. It gives full flexibility for thesimulation of customised train configurations using the European UIC brakesystem. Train length and vehicle arrangement can be adapted to the user’sspecific needs. For example, the test bench could be used for the simulation ofa train with distributed power. The system parameters are stored in a vehiclelibrary for the convenient generation of train configurations. This vehiclelibrary is freely expandable.The simulation is based on an equivalent electric circuit model which iscompleted with nozzle flow modelling. This model involves monitoring themain pipe, brake cylinder and reservoir pressure. Linear approximation is usedto obtain braking forces for the individual wagons and for the whole train. Thedepiction of the brake system behaviour is mostly accurate in the operationalscenarios, which is validated with measurement data. Additional calibrationis required for further reduction of the simulation errors and an extension ofthe model’s domain of validity. The test bench is developed by incrementaland iterative modelling and prepared for further improvements and variations,for example the adaption to the American AAR system variant.The presented work can also be used as a basis for similar implementationssuch as driving simulators. The methods are transferable to other applicationsof modular simulation. / Det här examensarbetet omfattar formgivningen och implementeringen aven digital provbänk för tyckluftsbromssystemet på godståg. Provbänken skaanvändas för att vidareutveckla befintliga bromsmodeller hos Transrail SwedenAB. De används för beräkningen av optimerade hastighetsprofiler förtåg i förarassistanssystemet CATO. Arbetet baserar sig på undersökningenav den tekniska bakgrunden, samt ett metodiskt angreppssätt för fysikaliskmodellering. Verktyget är implementerat på ett modulärt sätt. Provbänkenger full flexibilitet för simuleringen av skräddarsydda tågkonfigurationer somanvänder det europeiska UIC-bromssystemet. Tåglängd och fordonsanordningkan anpassas enligt användarens behov, till exempel för simulering av fördeladtraktion. Systemparametrarna lagras i ett fordonsbiliotek som förenklar inmatningenav tågkonfigurationer. Fordonsbiblioteket kan utvidgas enligt behov.Simuleringen är baserad på en ekvivalent strömkretsmodell, som kompletterasmed modellerad dysströmning. Simuleringen beskriver trycket ihuvudledningen, bromscylindern och förrådsluftsbehållaren. Bromskrafternaapproximeras linjärt efter trycken för de enskilda vagnarna såväl som helatåget. Simuleringen återger beteendet av bromssystemet i alla driftsituationerpå ett verklighetsnära sätt, enligt validering med mätdata från Knorr-Bremse:stestanläggning. Ytterligare kalibrering behövs för att minimera avvikelserna isimuleringen och för att utvidga modellens giltighetsdomän. Provbänken harutvecklats i stegvis modellering och är väl förberedd för vidareutveckling ochanpassning. Ett exempel är anpassningen för att simulera det amerikanskaAAR-bromssystemet.Arbetet som presenteras här är lämplig för användning i liknande applikationer,såsom körsimulatorer. Metoden kan tillämpas allmänt på övrigaanvändningsområden av modulär simulering.
38

-BLB- M/S Calmare Nyckel : Ballast-, Läns- &amp; Brandsystemet på M/S Calmare Nyckel / -BBF- M/S Calmare Nyckel : Ballast, Bilge &amp; Fire system on M/S Calmare Nyckel

Hjälte, Robert, Nordstrand, John January 2015 (has links)
Rapporten är skriven för att dokumentera den befintliga installationen av ballast-, läns- och brandsystem ombord på fartyget M/S Calmare Nyckel. I enlighet med uppdragets specifika-tioner kommer även förslag på förbättringar att presenteras. Förslagen bygger till största del på fakta från en leverantör av ventilkomponenter och av klassen ställda krav på installationen. Förbättringarna beaktar i huvudsak minskade risker och ökad säkerhet. De största skillnaderna med de nya förslagen är att länsvattensystemet skiljs från de övriga systemen, de viktigaste funktionerna fjärrstyrs med hjälp av pneumatik och systemets komponenter märks enligt branchstandard. / This report is produced to document the existing installation regarding the ballast, bilge and fire system aboard the vessel M/S Calmare Nyckel. According to the specifications of the assignment a proposal regarding improvements will also be presented. The suggestions are mainly based on data from a supplier of valve components and the demands put up by the classification society. The improvements are considered with reduced risk and increased safety in mind. The main differences in the new proposals are the separation of the bilge system from the other two systems, that the most vital functions can be remote-controlled by pneumatics and that all components are marked according to industry standard.
39

Analys och utveckling av drivsystemoberoende energiåtervinning

Gilani, Ramin January 2011 (has links)
Limitations in energy recovery technology require extended research for development of existing and alternative solutions. This thesis project has treated valuing pneumatic drivetrain independent energy recovery system as a potential solution. The prototype built during this project uses a piston compressor to transform kinetic energy into compressed air. The compressed air was then stored in two air tanks and transformed into kinetic energy with an air motor on demand. The prototype was built on a rig using a high power electrical engine to simulate energy input from the wheels during braking. The air motor was then used to rotate a Volvo S40 engine simulating energy output to the wheels. To further illustrate how the technology can be implemented in vehicles and to emphasize the variety of pneumatic energy recovery solutions a 3D CAD model was designed and other components was reflected. Such as using a screw compressor instead of piston and also using the compressor as a motor reducing the number of components optimizing the system. The system storing the kinetic energy does not mean that the vehicle can manage without an ordinary brake system. The regenerative braking effect rapidly reduces at lower speeds; therefore friction brake is still required in order to bring the vehicle to a complete halt.Analyses of strength of strained components acknowledge that limited energy recovery is possible without redimensioning the driveshaft´s. The limitation is regulated by the original dimension for engine load, with subject to the CV joint. Optimum positioning of the compressor due to the limited space in a modern vehicle is behind the gearbox in conjunction with the gearbox outgoing pinion for short energy transportation.Electrical energy recovery system is the solution with the highest potential on the market today but electrical vehicles covers just a fraction of the vehicle industry doe to technical and infrastructural limitations. Drivetrain independent pneumatic, hydraulic or mechanical energy recovery systems lay the foundation of a common ground for all vehicles and other waste energy machinery to use one energy recovery technology. The market research indicates that this type of technology is up-to-the-minute. / <p>Validerat; 20110106 (anonymous)</p>
40

Interoperable information model of a pneumatic handling system for plug-and-produce

Alt, Raphael, Wintersohle, Peter, Schweizer, Hartmut, Wollschläger, Martin, Schmitz, Katharina 25 June 2020 (has links)
Commissioning of a machine is still representing a very challenging operation and most steps are still executed manually by commissioning engineers. A future goal is to support the commissioning engineers and further automate the entire integration process of a newly installed system with a minimum of manual effort. This use case is known as plug-and-produce (PnP). In this contribution a concept of the Industrial Internet of Things is presented to improve the commissioning task for a pneumatic handling system. The system is based on a service-oriented architecture. Within this context, information models are developed to meet the requirements of PnP to provide relevant information via virtual representations, e.g. the asset administration shell, of the components to the commissioning process. Finally, a draft of the entire PnP process is shown, providing a general understanding of Industrial Internet of Things fluid power systems.

Page generated in 0.0658 seconds