<p>In this final thesis a rough description of aluminium extrusion is made, the importance of temperature of both the raw material and the extruded profile for a good profile quality. The difficulty in controlling these temperatures are discussed and attempts to increase the control are described. The attempts are basically made by controlling the furnace that is heating the raw material. This is done in a manner that the raw material reaches its final temperature shortly before it is extruded. An IR-camera at the press can be used for profile temperature measurements. The profile temperature is in turn used to decide the raw material temperature. Finally some proposals are given that can lead to a more controlled temperature at raw material and profile.</p>

In this final thesis a rough description of aluminium extrusion is made, the importance of temperature of both the raw material and the extruded profile for a good profile quality. The difficulty in controlling these temperatures are discussed and attempts to increase the control are described. The attempts are basically made by controlling the furnace that is heating the raw material. This is done in a manner that the raw material reaches its final temperature shortly before it is extruded. An IR-camera at the press can be used for profile temperature measurements. The profile temperature is in turn used to decide the raw material temperature. Finally some proposals are given that can lead to a more controlled temperature at raw material and profile.

Syftet med arbetet var att framställa en beräkningsmodell som behärskar att beräkna ett klimatsystems energiförluster samt livscykelanalys, LCC. Samt att använda denna modell vid jämförelse av två befintliga system. Modellen skapades i programmet Excell och använder sig av angiven indata för att beräkna resultat. Den användes för jämförelse av fyra lokaler i VIDEUM ABs byggnader. Två kontor och två föreläsningssalar jämfördes. Den beräknade skillnaden i energiförbrukning kunde i huvudsak härledas till det ena systemets längre drifttid över helgen samt att ett av kontoren drevs med högt konstantflöde hos ventilation även under frånvaro. Huruvida styrning av system sker efter koldioxidkoncentration eller temperatur verkar spela mindre roll för systemets förluster. Dock påverkar onödigt högt ställda flöden samt för långa driftstider energibehovet desto mer. / The thesis focused on compiling a calculation model suitable for calculating an indoor climate system energy demand and life cycle cost, LCC. The model was created in Excell and uses given input data to calculate the results. The model was used to compare four different premises located in buildings owned by VIDEUM AB in Växjö. Two offices and two lecture halls was compared. The calculated differences in energy demand could be derived to longer operating times during weekends for one system. One office had a large constant air flow even during absence which also led to a greater energy demand. Whether the system was regulated by using carbon dioxide concentrations or temperature as indicators on air quality didn’t seem to affect the energy demand significantly. Unnecessary high flow rates and operating times affects the premises energy demand the more.

The Friction Stir Welding (FSW) process has been under constant developmentsince its invention, more than 20 years ago. Whereas most industrial applicationsuse a gantry machine to weld linear joints, there are applications which consistof complex three-dimensional joints, requiring more degrees of freedom fromthe machines. The use of industrial robots allows FSW of materials alongcomplex joint lines. There is however one major drawback when using robotsfor FSW: the robot compliance. This results in vibrations and insufficient pathaccuracy. For FSW, path accuracy is important as it can cause the welding toolto miss the joint line and thereby cause welding defects.The first part of this research is focused on understanding how welding forcesaffect the FSW robot accuracy. This was first studied by measuring pathdeviation post-welded and later by using a computer vision system and laserdistance sensor to measure deviations online. Based on that knowledge, a robotdeflection model has been developed. The model is able to estimate thedeviation of the tool from the programmed path during welding, based on thelocation and measured tool forces. This model can be used for online pathcompensation, improving path accuracy and reducing welding defects.A second challenge related to robotic FSW on complex geometries is thevariable heat dissipation in the workpiece, causing great variations in the weldingtemperature. Especially for force-controlled robots, this can lead to severewelding defects, fixture- and machine damage when the material overheats.First, a new temperature method was developed which measures thetemperature at the interface of the tool and the workpiece, based on the thermoelectriceffect. The temperature information is used as input to a closed-looptemperature controller. This modifies primarily the rotational speed of the tooland secondarily the axial force. The controller is able to maintain a stablewelding temperature and thereby improve the weld quality and allow joining ofgeometries which were impossible to weld without temperature control.Implementation of the deflection model and temperature controller are twoimportant additions to a FSW system, improving the process robustness,reducing the risk of welding defects and allowing FSW of parts with highlyvarying heat dissipation.