Sökresultat:
74 Uppsatser om Friction - Sida 3 av 5
Naturlig haptisk kraftåterkoppling från volymdata
As the volumes are entering the world of computer graphics the pure volume visualisation becomes a more important tool in for example research and medical applications. But the advance in haptics --- force feedback from the computer --- is behind. In volume haptics no equal to the proxy method so popular in surface haptics has yet emerged. Some implementations of volume haptics even use surfaces as intermediate representations so that surface haptics can be used.The intention of this work was to create natural feeling haptic feedback from volumetric density data using pure volume haptics. The haptic algorithm would be implemented in Reachin API for the Reachin Desktop Display, together with other parts to build up a usable volume visualisation environment.To achieve the feeling of stiffness and Friction dependent on tissue type, a proxy based method was developed.
Utveckling av en metod och en utrustning för mätning av bränslesprayers rörelsemängd
A new type of device for measuring thev m& ?rate of fuel sprays from a diesel fuel injector has been developed and the various steps in the development are described. The device works by deflecting all of the sprays from the injector at the same time by using a bell shaped deflector. A load cell consisting of a machined steel part with strain gauges mounted on it measures the resulting force. The shape of the curvature in the deflector bell shape has been evaluated by photographing the flow in a 2D?version of the curve shape.
Krigets Atmosfär : Ett perspektiv på betydelsen av ovisshet i militära operationer
Ovissheten är en del i det Clausewitz benämner som krigets atmosfär, populär kallat krigets dimma. Det finns de som hävdar att ovisshet är något som kan avhjälpas med bättre sensorer samtidigt som det finns de som hävdar att ovissheten genomsyrar alla militära operationer. I det här arbetet skall ovissheten i ett specifikt fall belysas i syfte att möjiggöra en diskussion om hur ovissheten kan te sig i militära operationer. Arbetet sker genom en fallstudie av delar av den japanska invasionen av Malaysia 1941. Undersökningen bygger på en kvalitativ studie av två officerares olika syn på samma händelser. Fokus ligger vid att belysa ovisshet i deras föreställningar före och under invasionen.Studien resulterade i att ovissheten konkretiserades och indelades i de olika former som observerades under arbetet. Ovissheten visar sig vara ett vitt begrepp med många ursprung och olika påverkan. Avslutningsvis förs en diskussion rörande hur ovissheten kan hanteras för att om möjligt lindra de negativa effekter som ovissheten annars kan föra med sig. .
Upphovsrättens effekter på biblioteken : En diskussion kring bibliotekens position, verksamhet och framtid
This master thesis examines the copyright law with the purpose of sorting out the consequences and the effects of the law impacted on libraries. The theories used are mainly discourse analysis and public domain theory. At the centre of the examination is the effects that copyright law bring to libraries and their ability to perform their work. A major part of this thesis is gathered around the analysis of the presumptive key words that give the structures of copyright law the possibility to claim rightfulness. This is an outspoken strategy to illustrate the discourse of copyright law.
Obtaining high quality textile fibre from industrial hemp through organic cultivation
AbstractThe urgency to find alternative fabrics to conventionally produced cotton is increasing as vast amounts of agrochemicals are used and a lot of irrigation is required. In this literature survey the potential of organic cultivation practices to produce highly qualitative hemp fibre, suitable for the textile industry, was investigated. The definition of a fibre in the textile context as well as of the qualities that are essential for a textile fibre was necessary as a base for the discussion in this thesis. The quality parameters looked at were fineness, strength, length, Friction, and colour. The impact of external growth factors and plant development on these quality properties are discussed.
Snedställningskrafters påverkan på prefabricerade pelar-balk stommar
The aim of this thesis was to investigate if the robotized welding method FSW (Friction Stir Welding) could be applied for joining a rotating structure in an aero engine at Volvo Aero Corporation. FSW is expected to introduce less defects than today?s welding methods and could therefore be suitable for critical aero components. The material is the nickel based alloy Inconel 718, however a material experimentation is outside the scope of this report.The main goal of this study is to verify if the ESAB ROSIO robot based FSW-system has a suitable work space to be able to weld the rotating structure, and if the welding tool has accessibility to the joints. The FSW-process needs a rigid fixture, and a number of fix-ture concepts are presented based on a proposed weld sequence.
Friktionsmätning med pendelmetoden Temperaturkorrigering
SammanfattningPendelmetoden eller ?Pendulum Friction Tester? är en bärbar friktionsmätningsmetod för både gångytor och vägbanor. Den har funnits sedan 1940-talet men modifierades på 1960-talet med bland annat en ny skala som kallas för PTV (Pendulum Test Value). Ju halare ett ytmaterial är desto lägre PTV.Metoden använder bland annat två alternativa glidklackar kallade slider 57 respektive slider 96. Det är känt att PTV för slider 57 är temperaturberoende och minskar med ökande temperatur.
Diagnos av stiktion i reglerventiler för prediktivt underhåll
This master thesis reviews advances in detection and diagnosis of static Friction (stiction) in control valves. Control valves suffering from stiction results in oscillating control loops which in turn decreases both the process stability and reliability. Perstorp AB sees a necessity to automatically detect stiction in valves before the effects of the malfunctioning valves have become too severe. This thesis presents an introduction to maintenance, control loops and how stiction in valves can affect performance of control loops.A selection of methods presented in the literature are introduced and examined using normal operating data from the site in Perstorp. Common for all selected methods is their intuitive ideas and that they are based on normal operating data and minimum amount of process knowledge.
Observatörer för skattning av verktygspositionen hos en industrirobot : Design, simulering och experimentell verifiering
This thesis approaches the problem of estimating the arm angles of an industrial robot with flexibilities in joints and links. Due to cost-cutting efforts in the industrial robots industry, weaker components and more cost-effective structures have been introduced which in turn has led to problems with flexibilities, nonlinearities and Friction. In order to handle these challenging dynamic problems and achieve high accuracy this study introduces state observers to estimate the tool position.The observers use measurements of the motor angles and an accelerometer and the different evaluated observers are based on an Extended Kalman Filter and a deterministic variant. They have been evaluated in experiments on an industrial robot with two degrees of freedom. The experimental verification shows that the state estimates can be highly accurate for medium frequency motions, ranging from 3-30Hz.
Åtkomststudie för robotiserad svetsning av flygmotordetalj
The aim of this thesis was to investigate if the robotized welding method FSW (Friction Stir Welding) could be applied for joining a rotating structure in an aero engine at Volvo Aero Corporation. FSW is expected to introduce less defects than today?s welding methods and could therefore be suitable for critical aero components. The material is the nickel based alloy Inconel 718, however a material experimentation is outside the scope of this report.The main goal of this study is to verify if the ESAB ROSIO robot based FSW-system has a suitable work space to be able to weld the rotating structure, and if the welding tool has accessibility to the joints. The FSW-process needs a rigid fixture, and a number of fix-ture concepts are presented based on a proposed weld sequence.
Utveckling av golvlucka för hoppgropssystem i kommunal idrottshall
In this thesis a concept for floor hatches for foam pits has been developed. Since there is an existing solution that is powered by hydraulics and is expensive, the goal was to develop a cheaper solution, as simple as possible.A number of different concepts were developed and evaluated. A concept with five sections that are pulled to the side and stacked on each other was chosen as it was thought to have the lowest risk of crush injuries and to be easiest to manage and control. In the opening behind the foam mattress a lifting table is placed to regulate the height of the stacked sections.To be allowed to be installed in the floor of sports halls the sections must be dimensioned according to the construction standards for these types of buildings. Different dimensions of beams in steel and wood materials were evaluated and of those, who lived up to the requirements of the standard, a concept was chosen.
Drivaxeltrycksreglering hos tunga fordon : För en ökad framkomlighet vid vinterförhållanden
Heavy duty vehicles often have problems with traction during the winter periods. For vehicles that can lift tag axles it is possible to increase the normal force on the driven axle by lifting one or more tag axles, this will then increase the propulsive force of Friction. This however increases wear on both road and vehicle. A possibility to reduce the wear while achieving nearly equivalent traction compared to lifted tag axles is to allow the vehicle to regulate the normal force by lowering the pressure in the air suspension associated with the tag axles or by the lifting of these axles. The vehicle would then by itself be able to set just the right amount of normal force on the drive wheels to avoid unnecessarily high normal forces while maintaining sufficient traction.The purpose of the report is to find out which parameters affect heavy duty vehicles when driving on slippery slopes and how traction can be improved.
Diagnostiksystem i gaffeltruckar
This is a final thesis done at BT, considering one of their forklift truck models called Reflex. The first part of this report is about a preliminary investigation investigating what kind of diagnostic systems BTwants to use, and also which demands there are to meet all expectations on such system. Secondly a diagnostic system, which will show if the drive wheel is worn out, will be presented. In the preliminary investigation, two kinds of diagnostic systems were mentioned. These were Model based diagnosis and Predictive analysis.
Glidytor och ytjämnhet med avseende på friktion och tätning
Gliding and sealing functions in Öhlins shock absorbing systems sets great demands onthe contacting surfaces. In this particular case, the bushings and the sealings on acylinder piston. The surface wanted is a surface with both low Frictional forces and smallleakage. This study was done with the goals of investigating and determining existingsurfaces due to the Frictional force and leakage. How can we in an easy mannerdescribe these?A number of ten front forks were part of a main study.
New Generation Surface treatment for tools : A preliminary study
The surface finishing technique called black oxidation is currently being used on thetool holders made of low alloyed tool steel produced by Sandvik Coromant. Blackoxidation isn?t considered a sufficient technique because it doesn?t make the toolholders look like the quality products that they actually are. The reasoning behind thisis that the tool holders can show signs of corrosion after prolonged storing times orin countries with high humidity and temperature. The corrosion doesn?t decrease thetool holders performance, but the customers might believe otherwise.