Solar Orbiter is a mission launched in 2020 that will take images closer than ever of the Sun. It has ten instruments on board, including The Spectrometer/Telescope for Imaging X-rays (STIX) and The Extreme Ultraviolet Imager (EUI). STIX is a hard X-ray imaging spectrometer which observes bremsstrahlung from the non-thermal accelerated electrons in the footpoints of solar flares and from thermal hot plasma in flare loops. EUI consists of three telescopes, including a Full Sun Imager which is a one-mirror telescope that observes the solar corona and chromosphere in extreme ultraviolet (EUV) wavelengths 174Å and 304Å, respectively.   The purpose of the project was to determine the alignment between STIX and EUI to better understand and improve the pointing of STIX. It is important to know the accuracy of the pointing before using the instruments for science. The alignment was studied by looking at the flare location of the two instruments for about 30 flares. The flare location was approximated to be the brightest pixel in the image. The aspect solution of STIX was applied and this was also compared to the flare seen by EUI. For some of the flares, also imaging data from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) was used to get a more detailed comparison. One flare was studied in more detail, using thermal and non-thermal emission seen by STIX, EUV emission seen by EUI 174Å and AIA 171Å as well as UV emission seen by AIA 1600Å. For four flares, the flare location was determined from the visible ribbons and loops instead of the brightest pixel. The methods of finding the flare location by brightest pixel and by looking at flare features were compared.   The average difference between the EUI and STIX flare location was within 12 arcseconds with a standard deviation between 18 and 42 arcseconds for the brightest pixel method. This difference has two main contributions: the accuracy of the STIX aspect solutions and the accuracy of identifying the common source features in EUV and X-rays. To increase the accuracy of finding common sources, four flares with well defined ribbons and loops were analyzed in detail. For these events, the accuracy of the STIX aspect system was determined to be better than 10.5 arcseconds. This is still significantly higher than the design requirements of being better than 4 arcsecs. Detailed analysis clearly showed that the method of determining the flare location by brightest pixel was not accurate enough to evaluate the STIX pointing. Further studies need to be done to improve the aspect solution.

Du fait de la disponibilité de capteurs éléctroniques de plus en plus puissant, la dernière décennie a vu la popularisation de nouveaux dispositifs mobiles, comme les téléphones intelligents (smartphone), et même des dispositifs miniatures comme ceux de l'informatique portée. Ces nouveaux dispositifs apportent de nouveaux problèmes interactionnels, du fait de la petite taille de l'écran et du problème du "fat-finger" (lors de l'interaction, une large portion de l'écran se retrouve occultée par le doigt, et les tâches de pointage perdent en précision. L'objectif de ce travail est double : 1) d'acquérir une meilleure compréhension du pointage sur les petits dispositifs mobiles, grâce à une étude poussée de la loi Fitts, 2) de créer de nouvelles techniques d'interaction afin d'augmenter la bande passante interactionnelle entre l'utilisateur et le dispositif / Thanks to the availability of powerful miniaturized electronic coponents, this last decade have seen the popularization of small mobile devices such as smartphones, and even smaller devices for wearable computing. These new devices bring new interaction problems, such as the small size of the screen and the "fat-finger" problem (a relatively large portion of the sreen is occluded and pointing lacks precision). the objective of the work reported here is twofold : 1) to aquire a better understanding of pointing on small devices, thanks to an advanced study of Fitts' law, 2) to design new interaction techniques for increasing the interaction bandwidth between the user and the device.

Free-space optical communication (FSO) has been proposed as an attractive alternative to radio frequency communication in the sense that it provides wide bandwidth and high capacity without requirement of license. However, the scalability of FSO link is limited by pointing error, atmospheric turbulence, and loss. Especially, when it comes to the FSO link between moving platforms, it is imperative works to analyze the statistical channel model considering accurate pointing errors and atmospheric turbulence at the same time. In this paper, we analyze performance of FSO links over various atmospheric situations with pointing errors. First, we assume strong turbulence and obtain a unified approximation of the composite probability density function (PDF) of channel gain, which embraces generalized pointing error models. This approximation leads to new unified formulas for the bit error rate (BER) and outage capacity of a FSO link, which account for the two possible detection mechanisms of intensity modulation/direct detection (IM/DD) and heterodyne detection. Secondly, we statistically derive the unified composite PDF containing all possible pointing error models based on weak turbulence model. In addition, we analyze BER performance in FSO communication with IM/DD and heterodyne detection technology based on the derived unified composite PDF results. Finally, we investigate the ergodic capacity of unmanned aerial vehicle (UAV)-based FSO links over random foggy channel. More specifically, we derive composite PDF and close approximation for the moments of the composite PDF using the statistical model of a UAV-based 3D pointing error and a random foggy channel. With it, we obtain upper bound and asymptotic approximation of the ergodic capacity for the two possible detection techniques of IM/DD and heterodyne detection at high and low signal-to-noise ratio (SNR) regimes.

Robotics and space applications represent areas where compliant mechanisms can continue to make a significant impact by reducing costs and weight while improving performance. Because of the nature of these applications, a common need is for bearing replacement mechanisms, or mechanisms that perform the function of a bearing without the complexity and failure modes associated with bearings. Static balancing is a design strategy that attempts to reduce the actuation effort of a mechanism, and has been applied to compliant mechanisms in some applications. Monolithic construction, especially by means of 3D printing technology, is a strategy whereby the mechanism links and joints are built as a single "chunk" of material. This eliminates assembly and failure modes associated with wear and friction in traditional joints. In this work we examine these design strategies in the context of robotics and space applications. Matlab and Ansys batch files can be found in Appendix A. A fully compliant zero-torque, statically balanced mechanism is described that can undergo greater than 100 of motion. Because compliant mechanisms achieve their motion from the deflection of their constituent members, there is some strain energy associated with actuated positions. By introducing an appropriate pre-load, strain energy can be held constant. This can reduce or nearly eliminate the input force required from the actuating device. This paper describes the statically balanced rotary joint concept, and demonstrates its optimization, testing, and implementation for a haptic pantograph mechanism. The statically balanced properties of the constituent joints result in a mechanism with two balanced degrees of freedom. Matlab and Ansys batch files can be found in Appendix B. The conception, modeling, and development of a fully compliant two-degree-of-freedom pointing mechanism for application in spacecraft thruster, antenna, or solar array systems is described. The design objectives and the advantages of a compliant solution are briefly discussed. A single design concept is selected for final development from a field of generated concepts. Analytical and numerical models are accompanied by prototype testing and measurements in several iterations. A final design is described in detail, a fully compliant prototype is fabricated in titanium, and its performance is measured.

Future pointing devices for mobile gaming is a study of properties of a number of pointing devices, and how these properties make them suitable for gaming in a mobile environment. Today, most of all advanced computer games is played with a mouse, which make the laptop and its touch-pad bad for gaming. For many decades the optical computer mouse has been the leading pointing device for playing computer games, and its have been scientifically that players with a computer mouse out-perform players with a joy-stick or other pointing devices when playing games with importance of precision. A mouse can be plugged to a laptop, but not without compromising the mobility which is significant for the laptop. Two studies discovered the user experience and functional performance of playing a precision game with an optical computer mouse, joystick, eye-tracker, touchpad and accelerometer. Our studies showed that users preferred to use the mouse when playing precision computer games, with joystick and touchpad as second choices. The eye-tracker where very unfamiliar for the users but was performing almost as accurate as the touch-pad. The accelerometer was the worst pointing device according to the test persons, and by the functional study of the performance of the pointing devices. Their result was by the falling order of mouse, touchpad, joystick, eye-tracker and at last the accelerometer. An interesting way of developing a new pointing device would be to use the mobility and precision of an eye-tracker. The eye-tracker could state a region of interest of the screen where a complementary touch pad could be in use to release your eyes from being the pointing device. It would give you the opportunity to aim with the touchpad and letting you check your surrounding with your eyes. / Detta är ett arbete som ämnar att hitta egenskaper hos ett pekdon som kan komma att ersätta den optiska datormusen i vissa miljöer. De flesta datorspel spelas med en mus. En mus kan självklart kopplas in i en laptop, men inte utan att kompromissa på den mobilitet som ofta är förknippad med en bärbar dator. Det utfördes två studier av användbarhet samt funktionalitet av pekdonen optisk datormus, joystick, ögonspårare, pekplatta och accelerometer. Testpersonerna föredrog musen vid spelande av precisionsspel, där ögonspårare och pekplatta var andrahandsval. Ögonspåraren var okänd för testpersonerna men presterade nästan lika bra som pekplattan. Accelerometern var det sämsta pekdonet enligt testpersonerna, men också enligt studien av pekdonens användbarhet. Ett intressant utvecklingsområde för ett nytt pekdon vore att nyttja mobiliteten och precisionen hos ögonspåraren för att upprätta region av intresse på skärmen. I denna region kan sedan en kompletterande pekplatta ta över.

Hardware configurations, a control law, and a steering law are developed for a mixed hardware spacecraft that uses both control moment gyros and reaction wheels. Replacing one or more gyros in a spacecraft with a reaction wheel has potential for cost savings while still achieving much greater performance than using reaction wheels alone. Several simulated tests are run to compare the performance to a traditional all reaction wheel or all control moment gyro spacecraft, including analysis of failure modes and singular configurations. The mixed system performed similarly to all gyro systems, responding within 6% of the gyro system’s time for all nominal cases. It far exceeds the performance of reaction wheel systems, taking only a fourth of the time. It also handles failures better than reduced size gyro systems. As such, it can be an effective cost saving measure for certain satellite missions.

During the course of time, artificial selection has given rise to a great diversity among today's dogs. Humans and dogs have evolved side by side and dogs have come to understand human body language relatively well. This study investigates whether selection pressure and domestication could reveal differences in dogs’ skill to interpret human directional cues, such as distal pointing. In this study, 46 pet dogs were tested from 27 breeds and 6 crossbreeds for performance in the two-way object choice task. Breeds that are selected to work with eye contact of humans were compared with breeds that are selected to work more independently. Dogs of different skull shape were also compared, as well as age, sex and previous training on similar tasks. No significant differences in performance were found between dogs of various age, sex or skull shape. There was a tendency for significant difference in performance if the dog had been previously trained on similar tasks. When dogs that made 100% one-sided choices were excluded, a tendency appeared for there to be a difference between the cooperative worker breeds compared to the other breeds for the time it took for dogs to make a choice. There is a correlation between the number of correct choices made and the latency for the dogs from being release to making a choice (choice latency). All groups of dogs, regardless of my categorization, performed above chance level, showing that dogs have a general ability to follow, and understand, human distal pointing.

At present, human-computer interaction (HCI) is no longer limited to traditional input hardware like mouse and keyboard. In the last few years, Augmented and Virtual Reality (AR, VR) have dramatically changed the way we interact with a computer. Currently, one of the many design challenges of these systems is the integration of the physical and digital aspects in an accessible and usable way. The design success of AR systems depends on the fluid and harmonious fusion of the material and digital world. Pointing, which is a radical gesture in communication, can enable easy and intuitive interaction within the AR application. This study explores two pointing techniques that can be used in an AR application. I developed two prototypes, and the concept of laser pointing was used, by shooting out a laser from the point of origin into the application, to perform pointing. The point of origin for the laser is the camera, in the first prototype called camera laser and the fiducial, in the second prototype called pen laser. The camera laser showed promising results in terms of ease of use and reliability, but the pen laser felt more natural to the user. In this study, I present the prototypes, followed by the user study and the results. / För närvarande är interaktionen mellan människa och dator (HCI) inte längre begränsad till traditionaell ingångshårdvara som mus och tangentbord. Under de senaste åren har Augmented och Virtual Reality (AR, VR) dramatiskt förändrat vårt sätt att interagera med en dator. För närvarande är en av de måmga designutmaningarna för dessa system att sammanföra de fysiska och digitala aspekterna på ett tillgångligt och användbart sätt. AR-systemens framgång beror på den löpande och harmoniska sammansmältningen av den materiella och digitala världen. Pekande, som är ett radikalt sätt att kommunicera på, kan möjliggöra enkel och intuitiv interaktion inom AR-användning. Denna studie undersöker två pektekniker som kan användas i AR-användning. Jag utvecklade två prototyper. Laserpekning användes genom att skjuta ut en laser från startpunkten till applikationen, för att utföra pekning. Utgångspunkten för lasern är kameran, i den första prototypen som kallas kameralaser och fiducial, i den andra prototypen som kallas pennlaser. Kameralasern visade lovande resultat när det gäller användarvånlighet och tillförlitlighet, men pennlasern upplevdes mer naturlig för användaren. I denna studie presenterar jag prototyperna följt av användarstudien och resultaten.

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