In the locomotion design space, artificial locomotion is most commonly used when navigating virtual spaces larger than the physical space provided. Some significant challenges to the use of artificial locomotion are however cybersickness and disorientation. Cybersickness is a phenomenon that creates discomfort for the user and is believed to be inflicted by continuous movement and its creation of vection. Contrarily, discrete locomotion interfaces like teleportation do not cause vection or cybersickness for the user. However, because of this, teleportation is unable to offer spatial updating, which is crucial for preventing disorientation. This thesis investigates an alternative to these interfaces that aims to combine their benefits while avoiding their drawbacks in an interface referred to as Stepwise teleportation that consist of short discrete translations, referred to as steps, in the direction chosen by the user. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

Dielectric elastomer actuators (DEAs) have been used for artificial muscles for years. Recently the DEA-based deformable surfaces have demonstrated controllable microscale roughness, ease of operation, fast response, and possibilities for programmable control. DEA muscles used in bioinspired robotic arms for large deformation and strong force also become desirable for their efficiency, low manufacturing cost, high force-to-weight ratio, and noiseless operation. The DEA-based responsive surfaces in microscale roughness control, however, exhibit limited durability due to irreversible dielectric breakdown. Lowering device voltage to avoid this issue is hindered by an inadequate understanding of the electrically-induced wrinkling deformation as a function of the deformable dielectric film thickness. Also, the programmable control and geometric analysis of the structured surface deformation have not yet been fully explored. Current methods to generate anisotropic wrinkles rely on mechanical pre-loading such as stretching or bending, which complicates the fabrication and operation of the devices. With a fixed mechanical pre-loading, the device can only switch between the flat state and the preset wrinkling state. In this thesis, we overcome these shortcomings by demonstrating a simple method for fabricating fault-tolerant electro-responsive surfaces and for controlling surface wrinkling patterns. The DEA-based system can produce different reversible surface topographies (craters, irregular wrinkles, structured wrinkles) upon the geometrical design of electrode and application of voltage. It remains functional due to its ability to self-insulate breakdown faults even after multiple high voltage breakdowns, and the induced breakdown punctures can be used for amplification of local electric fields for wrinkle formation at lower applied voltages. We enhance fundamental understanding of the system by using different analytical models combined with numerical simulation to discuss the mechanism and critical conditions for wrinkle formation, and compare it with the experimental results from surface topography, critical field to induce wrinkles in films of different thickness, and wrinkling patterns quantitatively analysed by different disorder metrics. Based on the results, we demonstrate its wide applicability in adjustable transparency films, dynamic light-grating filter, molding for static surface patterns, and multi-stable mirror-diffusor-diffraction grating device. For DEAs used for macroscopic-scale deformation in robotic arms, the main issue that undermines the performance of DEA muscles is the trade-off between strong force and large displacement, which limits the durability and range of potential robotic and automation applications of DEA-driven devices. In this thesis, this challenge is tackled by using DEAs in loudspeaker configuration for independent scaling-up of force and displacement, developing a theoretical prediction to optimise the operation of such DEAs in bioinspired antagonistic system to maximise speed and power of the robotic arm, and designing a clutch-gear-shaft mechanical system collaborating with the muscles to decouple the displacement and output force. Therefore, the trade-off between force and displacement in traditional DEA muscles can be resolved. The mechanical system can also convert the short linear spurt to an unlimited rotary motion. Combining these advantages, continuous movement with high output force can be accomplished.

[ES] El propósito fundamental perseguido en esta tesis es el de establecer las relaciones entre el movimiento y la interpretación. Se ofrece una perspectiva global del fenómeno, a partir de la concepción holístico-kinética personal centrada en el repertorio actual para percusión. Las decisiones teórico-interpretativas son fruto de la reflexión y la continua praxis artística y docente realizada a lo largo de los años. Por una parte, a través de recitales tanto como solista como en diferentes proyectos relacionados con la creación, interpretación y difusión del arte de la percusión y por otra, en el desempeño de la función docente como especialista en distintos ámbitos y niveles. Se establecen las bases conceptuales necesarias para extrapolar unos principios comunes a los diferentes instrumentos o conjuntos de instrumentos a través de la interpretación del gran repertorio contemporáneo. El trabajo de investigación se lleva a cabo a partir del análisis, grabación, entrevistas a grandes intérpretes, estudios y trabajos similares en otros campos asociados por su empleo del movimiento como medio de expresión. La tesis cristaliza en diferentes resultados y conceptos teórico-prácticos que se ven reflejados en la edición de una partitura, la definición de unos principios generales interpretativos y la grabación en distintos formatos de las diferentes piezas que conforman el corpus principal de estudio. Los registros audiovisuales se agrupan en dos bloques: la edición de un CD de audio con 5 piezas del repertorio contemporáneo para percusión y clarinete bajo, y la grabación de las tres piezas fundamentales de la tesis en formato de video de alta calidad de acceso libre en la red. / [CA] El propòsit fonamental perseguit en aquesta tesi és el d'establir les relacions entre el moviment i la interpretació. S'ofereix una perspectiva global del fenomen, a partir de la concepció holístic-cinètica personal centrada en el repertori actual per percussió. Les decisions teòric-interpretatives són fruit de la reflexió i la contínua praxi artística i docent realitzada al llarg dels anys. D'una banda, a través de recitals tant com a solista com en diferents projectes relacionats amb la creació, interpretació i difusió de l'art de la percussió i per una altra, en l'exercici de la funció docent com a especialista en diferents àmbits i nivells. S'estableixen les bases conceptuals necessàries per extrapolar uns principis comuns als diferents instruments o conjunts d'instruments a través de la interpretació del gran repertori contemporani. El treball de recerca es porta a terme a partir de l'anàlisi, gravació, entrevistes a grans intèrprets, estudis i treballs similars en altres camps associats que empren el moviment com a mitjà d'expressió. La tesi cristal·litza en diferents resultats i conceptes teoricopràctics que es veuen reflectits en l'edició d'una partitura, la definició d'uns principis generals interpretatius i l'enregistrament en diferents formats de les diferents peces que conformen el corpus principal d'estudi. Els registres audiovisuals s'agrupen en dos blocs: l'edició d'un CD d'àudio amb 5 peces del repertori contemporani per a percussió i clarinet baix, i l'enregistrament de les tres peces fonamentals de la tesi en format de vídeo d'alta qualitat d'accés lliure a la xarxa. / [EN] The fundamental purpose pursued in this thesis is to establish the relationships between movement and interpretation. A global perspective of the phenomenon is offered, starting from the personal holistic-kinetic conception centered on the current repertoire for percussion. Theoretical-interpretative decisions are the result of reflection and continuous artistic and teaching practice carried out over the years. On the one hand, through recitals both as a soloist and in different projects related to the creation, interpretation and dissemination of the art of percussion and, on the other, in the performance of the teaching function as a specialist in different fields and levels. The necessary conceptual bases are established to extrapolate some common principles to the different instruments or sets of instruments through the interpretation of the great contemporary repertoire. The research work is carried out from the analysis, recording, interviews with great interpreters, studies and similar works in other fields associated with their use of movement as a means of expression. The thesis crystallizes in different results and theoretical-practical concepts that are reflected in the edition of a score, the definition of general interpretive principles and the recording in different formats of the different pieces that make up the main corpus of study. The audiovisual records are grouped into two blocks: the edition of an audio CD with 5 pieces of the contemporary repertoire for percussion and bass clarinet, and the recording of the three fundamental pieces of the thesis in free access high-quality video format in network. / Soriano Morales, J. (2021). Una visión holística del movimiento en el arte de la percusión actual a través de la aplicación de una concepción kinética personal [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172193 / TESIS

<p>When users begin to experience virtual reality (VR) for the first time, they can be met with some degree of motion sickness and nausea, especially if continuous joystick locomotion is used. The symptoms that are induced during these VR experiences fall under the umbrella term cybersickness, and due to these uncomfortable experiences, these users can get a bad first impression and abandon the innovative technology, not able to fully appreciate the convenience and fascinating adventures VR has to offer. As such, this project compares the effects of two cybersickness mitigation methods (Dynamic Field of View (FOV) and Virtual Reference Frame), both against each other and combined, on user-reported cybersickness symptoms to determine the best combination to implement in commercial applications to help create more user-friendly VR experiences. The hypothesis is that combining the FOV reduction and the resting frame methods can mitigate VR cybersickness more effectively without hindering the user’s experience and the virtual nose method is more potent at mitigating cybersickness compared to dynamic FOV. To test these hypotheses, an experimental game was developed for the Meta Quest 2 with five levels: a tutorial level and four maze levels (one for each scenario). The participants were asked to complete the tutorial level until they got used to the virtual reality controls, and then they were instructed to complete the maze level twice with one of the following conditions for each run: no method, dynamic field of view only, virtual nose only, and dynamic field of view and virtual nose combined. After completing each maze trial, the participants were asked to complete a simulator sickness questionnaire to get their thoughts on how much sickness they felt during the test. Upon concluding the testing phase with 36 participants and compiling the data, the results showed that while the subjects preferred the dynamic FOV method even though they were able to complete the trials significantly faster with the virtual nose method, it is inconclusive regarding which method is truly more effective. Furthermore, the results showed that it is also inconclusive if the scenario with both methods enabled is significantly better or worse than either method used separately.</p>