>Magister Scientiae - MSc / In this study a complete set of exclusive (~p; 2p) polarization transfer observables of closed-shell oxygen isotopes are calculated using both direct and inverse kinematics using the relativistic plane wave impulse approximation. The interaction matrix is written in terms of the SPVAT (scalar, pseudoscalar, vector axial vector, tensor) covariants where each amplitude is obtained directly from experimental phase shifts. A relativistic mean eld theory approximation is used to compute boundstate wave functions of the nucleons. We study the evolution of polarization transfer observables within oxygen isotopes and identify observables which may discriminate between these isotopes. The same kinematical conditions are considered for both direct and inverse kinematics: the incident energy is set at 504 MeV and coplanar angles are xed at (22:12 ;􀀀40:30 ). The results indicate that only three spin observables, namely, Ay, P and Dnn distinguish di erent oxygen isotopes at these kinematical conditions in the inverse kinematics.

When trying to make a game character come alive and add some sense of realism to a game, it can be done in multiple ways. Animating a 3D model is the commonly used one and it is usually done by hand. The artist moves the model's limbs bit by bit to make small animation clips that are then played in the game. This has a few drawbacks, it's time consuming and depending on what the character is doing in the game it won't always look accurate. Ragdolls can be used together with animations to help bring more realism to the model. Together with animation and colliders on the model limbs, it can simulate when the models limbs interact with objects on the screen. It can also simulate physical responses that happen. But some problems still remain that can't be solved by ragdolls and animation alone. One example is the foot position when a character walking up or down sloped terrain. The foot can clip through the terrain and destroy the sence realism, however ragdolls together with inverse kinematics can solve such problems.

Continuum robots are the biologically inspired robots that mimic the behaviors of mammalian tongues, elephant trunks, and octopus arms. These robots feature a backboneless structure similar to their biological counterparts, such as termed muscular hydrostats. The drawbacks of two existing designs are examined and a new mechanical design that uses a single latex rubber tube as the central member is proposed, providing a design that is both simple and robust. Next, a novel verification procedure is applied to examine the validity of the proposed model in two different domains of applicability. A two-level electrical control scheme enables rapid prototyping and can be used to control the continuum robot remotely with a joystick via a Local Area Network (LAN). Next, a new geometrical approach to solve inverse kinematics for continuum type robot manipulators is introduced. Given the tip of a three-section robot, end-points of section 1 and section 2 are computed, and a complete inverse kinematics solution for a multisection continuum robot is then achieved by applying inverse kinematics to each section continuum trunk. Moreover, the algorithm provides a solution space rather than a single valid solution. Finally, the techniques involved in visualization of AirOctor/OctArm in 3D space in real-time are discussed.The algorithm has been tested with several system topologies.

Denna studie har undersökt huruvida Inverse Kinematics kan användas tillsammans med spelets miljö för att förbättra en karaktärs animationer och rörelse. Artiklarna som diskuteras i arbetet har använts som inspiration för att skapa artefakterna som använts i undersökningen. En kvantitativ undersökning genomfördes där deltagarna fick spela igenom två demoversioner, en med Inverse Kinematics kombinerat med animationer och en utan. Sedan fick deltagarna svara på en enkät om hur de upplevde spelkaraktärens rörelser. Utifrån svaren i undersökningen kunde slutsatsen dras att skillnaderna i animationerna knappt var märkbara då spelarna fokuserade på andra saker i spelet. Med hjälp av en större mer utförlig undersökning skulle arbetet i framtiden kunna användas inom spelbranschen för att förbättra animationer.

Tato práce popisuje další vývoj výukového sériového manipulátoru se třemi stupni volnosti. Práce se zabývá jednoduchou mechanickou úpravou manipulátoru, ale především pak softwarovou částí. Výsledkem je pak hra piškvorky, kdy manipulátor umožňuje hru proti lidskému protějšku. První část práce je věnována zlepšení inicializačního procesu manipulátoru a následně pak i návrhem vhodné polohové regulace. V další části je manipulátor rozšířen o jeden stupeň volnosti. Součástí je i návrh koncového efektoru vhodného pro psaní. Z takto upraveného manipulátoru je sestaven kinematický model vhodný pro real-time řízení. Dalším krokem v práci je návrh samotné aplikace hry piškvorky. Je navržen vhodný hrací algoritmus, včetně detekce a rozpoznání znaků v hracím poli pomocí kamery. Následně je vše implementováno do real-time aplikace, kde komunikaci s uživatelem zajišťuje navržené uživatelské rozhraní.

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No / In this paper we present a constrained inverse kinematics algorithm for real-time motion capture in virtual environments, that has its origins in the simulation of multi-body systems. We apply this algorithm to an articulated human skeletal model using an electromagnetic motion tracking system with a small number of sensors to create avatar postures. The method offers efficient inverse kinematics computation and it is also generalised for the configurations of an articulated skeletal model. We investigate the possibility of capturing fast gestures by analysing the convergence patterns of the algorithm with the motion tracking sampling frequency for a range of actions.

This thesis focuses on the problem of determining appropriate skeletal configurations for which a virtual animated character moves to desired positions as smoothly, rapidly, and as accurately as possible. During the last decades, several methods and techniques, sophisticated or heuristic, have been presented to produce smooth and natural solutions to the Inverse Kinematics (IK) problem. However, many of the currently available methods suffer from high computational cost and production of unrealistic poses. In this study, a novel heuristic method, called Forward And Backward Reaching Inverse Kinematics (FABRIK), is proposed, which returnsvisually natural poses in real-time, equally comparable with highly sophisticated approaches. It is capable of supporting constraints for most of the known joint types and it can be extended to solve problems with multiple end effectors, multiple targets and closed loops. FABRIK wascompared against the most popular IK approaches and evaluated in terms of its robustness and performance limitations. This thesis also includes a robust methodology for marker prediction under multiple marker occlusion for extended time periods, in order to drive real-time centre of rotation (CoR) estimations. Inferred information from neighbouring markers has been utilised, assuming that the inter-marker distances remain constant over time. This is the firsttime where the useful information about the missing markers positions which are partially visible to a single camera is deployed. Experiments demonstrate that the proposed methodology can effectively track the occluded markers with high accuracy, even if the occlusion persists for extended periods of time, recovering in real-time good estimates of the true joint positions. In addition, the predicted positions of the joints were further improved by employing FABRIK to relocate their positions and ensure a fixed bone length over time. Our methodology is tested against some of the most popular methods for marker prediction and the results confirm that our approach outperforms these methods in estimating both marker and CoR positions. Finally, an efficient model for real-time hand tracking and reconstruction that requires a minimumnumber of available markers, one on each finger, is presented. The proposed hand modelis highly constrained with joint rotational and orientational constraints, restricting the fingers and palm movements to an appropriate feasible set. FABRIK is then incorporated to estimate the remaining joint positions and to fit them to the hand model. Physiological constraints, such as inertia, abduction, flexion etc, are also incorporated to correct the final hand posture. A mesh deformation algorithm is then applied to visualise the movements of the underlying hand skeleton for comparison with the true hand poses. The mathematical framework used for describing and implementing the techniques discussed within this thesis is Conformal GeometricAlgebra (CGA).

Ce document présente la mesure de rendements isotopiques issus de la fission de l'U238 obtenus suite à l'expérience SOFIA réalisée au GSI à Darmstadt (août 2012). Cette expérience novatrice utilise la technique de la cinématique inverse relativiste, qui présente plusieurs avantages : les fragments de fissions sont focalisés vers l'avant dans un cône de faible ouverture angulaire (grande efficacité géométrique), et possèdent un état de charge nul ce qui facilite considérablement la mesure des rendements élémentaires. Le dispositif SOFIA se compose tout d'abord d'une cible active, dans laquelle a lieu la fission par excitation coulombienne et d'une chambre d'ionisation qui permet à la fois la mesure de la charge nucléaire et de l'angle horizontal des deux fragments en coïncidence. La mesure des masses est faite en déterminant le rayon de courbure des fragments, déviés par un puissant aimant (ALADIN), grâce à deux détecteurs de positions (MWPC), et par une mesure de temps de vol, qui nécessite une résolution extrême d'environ 40 ps FWHM pour que la séparation des isotopes lourds voisins soit acceptable. L'analyse des données montre que les objectifs initiaux ont étés remplis, puisque la séparation isotopique est atteinte sur toute la gamme des fragments de fission. Un effet pair-impair significatif est observé dans les rendements en charge, dont le spectre présente, comme attendu, une valeur moyenne pour la charge lourde très proche de Z = 54. L'effet pair-impair neutron présente, étonnamment, une amplitude et une forme très similaire à celle mesurée sur des fissions en neutrons thermiques. Le rapport pic/vallée des distributions en masses indiquent que l'énergie d'excitation est proche des 14 MeV attendus. Enfin, nos mesures sont très souvent comparées au code GEF qui donne des résultats toujours très proches des nôtres. / The isotopic fission yields of U 238 following the SOFIA experiment, conducted at the GSI facility (Darmstadt), are presented here. This experiment takes advantage of the inverse kinematics technique at relativistic energies. Benefits are several : fission fragments are highly focused (high geometrical efficiency) and are also completely stripped, which greatly simplifies their nuclear charge measurement. The first detector of the SOFIA setup is an active target in which fission occurs via electromagnetic excitation, followed by an ionization chamber to measure the nuclear charge and the horizontal angle of both fission fragments. The masses are deduced by the bending radius measurement of the fragments, deflected by a strong magnet (ALADIN), thanks to two position detectors (MWPC), and also by a highly resolved time-of-flight measurement (40 ps FWHM) so that heavy neighboring isotopes can be separated. The data analysis shows that the main goals are achieved since the isotopic separation is reached over the whole range of the fission fragments. A strong even-odd effect is seen in the charge spectrum, which also exhibits a mean heavy charge close to Z = 54. Surprisingly, the neutron even-odd effect of the light region is seen to be very close to the one in thermal neutron induced fission. The peak-to-valley ratio of the mass spectrum confirms that the mean excitation energy at fission is close to the expected one (14 MeV). The GEF code is used for comparison and always gives results very close to ours.

The prostheses used by the majority of persons with upper limb amputations today offer a limited range of motion. Relative to anatomical joints transradial (below the elbow) prosthesis users lose at least two of the three degrees of freedom provided by the wrist and forearm. Some myoeletric prostheses currently allow for forearm pronation and supination (rotation about an axis parallel to the forearm) and the operation of a powered prosthetic hand. Body-powered prostheses, incorporating hooks and other cable driven terminal devices, have even fewer active degrees of freedom. In order to perform activities of daily living, an amputee must use a greater than normal range of movement from other anatomical body joints to compensate for the loss of movement caused by the amputation. By studying this compensatory motion of prosthetic users, the mechanics of how they adapt to the loss of range of motion in a given limb and specific tasks were analyzed. The purpose of this study is to create a robotic based kinematic model that can predict the compensatory motion of a given task using given subject data in select tasks. The tasks used in this study are the activities of daily living: opening a door, drinking from a cup, lifting a box, and turning a steering wheel. For the model the joint angles necessary to accomplish a task are calculated by a simulation for a set of prostheses and tasks. The simulation contains a set of configurations that are represented by parameters that consist of the joint degrees of freedom provided by each prosthesis, and a set of task information that includes joint constraints and trajectories. In the simulation the hand or prosthesis follows the trajectory to perform the task. Analysis of tasks is done by attaching prosthetic constraints to one of the arms of the upper body model in the simulation, other arm maintains an anatomical configuration. By running the model through this simulation with different configurations the compensatory motions were found. Results can then be used to select the best prosthesis for a given user, design prostheses that are more effective at selected tasks, and demonstrate some possible compensations given a set of residual joint limitations with certain prosthetic components, by optimizing the configuration of the prostheses to improve their performance.