The underestimation of depth in virtual environments at mediumield distances is a well studied phenomenon. However, the degree by which underestimation occurs varies widely from one study to the next, with some studies reporting as much as 68% underestimation in distance and others with as little as 6% (Thompson et al. [38] and Jones et al. [14]). In particular, the study detailed in Jones et al. [14] found a surprisingly small underestimation effect in a virtual environment (VE) and no effect in an augmented environment (AE). These are highly unusual results when compared to the large body of existing work in virtual and augmented distance judgments [16, 31, 36–38, 40–43]. The series of experiments described in this document attempted to determine the cause of these unusual results. Specifically, Experiment I aimed to determine if the experimental design was a factor and also to determine if participants were improving their performance throughout the course of the experiment. Experiment II analyzed two possible sources of implicit feedback in the experimental procedures and identified visual information available in the lower periphery as a key source of feedback. Experiment III analyzed distance estimation when all peripheral visual information was eliminated. Experiment IV then illustrated that optical flow in a participant’s periphery is a key factor in facilitating improved depth judgments in both virtual and augmented environments. Experiment V attempted to further reduce cues in the periphery by removing a strongly contrasting white surveyor’s tape from the center of the hallway, and found that participants continued to significantly adapt even when given very sparse peripheral cues. The final experiment, Experiment VI, found that when participants’ views are restricted to the field-of-view of the screen area on the return walk, adaptation still occurs in both virtual and augmented environments.

This work has investigated how head-mounted-displays can enable more efficient and better work conditions for warehouse workers. Head-mounted-displays have increased in popularity among companies because of an increase in the field of e-commerce, therefore warehouse labour was an interesting area to review. The purpose of this project has been to investigate how head-mounted-displays can simplify warehouse work and to find an area where Tangar can be utilized. Tangar is an application to facilitate indoor navigation by helping users to reach points of interest. Through a mixed methodology approach that utilizes both quantitative and qualitative methods, a broad understanding in warehouse and inventory management have been established. The potentials of head-mounted display were evaluated using empirical and theoretical studies. Based on an early concept that was evaluated by a collaboration with a warehouse-solution company, factors that are of importance in warehouse management were identified. A decision to direct the project towards order picking was taken as it is a fundamental process within warehouse management. Three concepts were generated that harness the benefits of head-mounted-displays. With an informed decision the benefits for each of the concepts were compared with important parameters for a profitable warehouse management. It turned out that "Pick-by-Light", a common system in warehouse management, can be made virtual using head-mounted-displays. Since the system had never previously been operated virtually, an extensive study needed to be done in order to evaluate the viability in order-picking to propose a final concept. An experimental environment was set for the empirical studies, and two other common order picking systems were compared to the virtual Pick-by-Light system. Quantitative data in the form of time measurements from the order picking as well as picking errors and qualitative data from a NASA-TLX survey, was extracted from twelve users. A total of 360 samples from the quantitative study and 36 questionnaires from the qualitative study was then analysed. The result resembled those from similar studies with a conventional Pick-by-Light system. Thus, parallels were drawn that indicated that the virtual system had good potential to perform at least as well as a regular Pick-by-Light. A virtual Pick-by-Light system might be able to reduce implementation-, work- and operational costs as the use of material is replaced by a virtual product, and also no installation is required. With the combination of Tangar, there is also a potential that a virtual Pick-by-Light system could be more efficient and accurate. The disadvantages of the conventional Pick-by-Light system are also that confirmations are ineffective and that workers find it difficult to get an overview of pickplaces. Which can potentially be eliminated with the proposed concept. However, a new generation of hardware and further studies are required in order to establish a final concept. The Magic Leap One, which is the head-mounted-display used in the project, is new. Many problems regarding the display have been discovered during the project and affected the results of the user studies. Further studies need to be done with other displays to determine the validity of the results of this work. In summary, this work gives an introduction in how "Mixed-reality" can be used in warehouse management and recommendations for continued work. / Det här arbetet har undersökt hur huvudmonterade skärmar kan möjliggöra ett effektivare och bättre arbete för lager-personal. Huvudmonterade skärmar har ökat i popularitet bland företaget på grund av ökningen inom e-handel och därför var lagerarbete ett intressant område att undersöka. Syftet med det här projektet har varit att undersöka hur huvudmonterade skärmar fortsatt skulle kunna förenkla lagerarbete samt att ta hitta ett område där Tangar kan användas. Tangar är en applikation som förenklar inomhus navigering genom att leda användaren till valda intressepunkter. Genom en metodisk undersökning som utnyttjar både kvantitativa och kvalitativa metoder, har en bred bakgrund inom lagerhantering kunnat upprättas. Potentialen av att använda huvudmonterade skärmar har undersökts genom empiriska och teoretiska studier. Baserat på ett tidigt koncept som utvärderas genom ett samarbete med ett sakkunnigt företag, identifierades flertalet faktorer som är av vikt i lagerhantering. Ett beslut om att rikta projektet mot order-plockning togs då det är en fundamental process inom lagerabete. Tre koncept genererades som utnyttjar fördelarna med huvudmonterade skärmar. Genom att ta ett informativt beslut, kunde fördelarna för var och ett av koncepten jämföras med viktiga parametrar för ett lönsamt lagerarbete. Det visade sig att ”Pick-by-Light”, ett vanligt system inom lagerhantering, kunde göras virtuellt med hjälp av huvudmonterade skärmar. I och med att systemet tidigare aldrig utförts virtuellt, behövdes en omfattande studie göras för att evaluera dess potential inom order-plockning för att kunna föreslå ett slutgiltigt koncept. En experimentell miljö sattes upp som ram för de empiriska studierna och två andra vanliga order-plocknings system kunde jämföras mot det virtuella Pick-by-Light systemet. Kvantitativa data i form av orderplockningstider samt plock-fel och kvalitativa data från observationer samt en NASA-TLX enkät, kunde extraheras från tolv användare. Totalt kunde 360 stickprov från den kvantitative studien och 36 enkäter från den kvalitative studien därefter analyseras. Resultatet liknade det som observerats i liknande studier där ett vanligt Pick-by-Light system evaluerats. Därmed kunde paralleller dras som visade att det virtuella systemet hade god potential till att kunna prestera åtminstone lika bra som ett vanliga Pick-by-Light systemet och ett koncept togs fram för vidare utveckling. Ett virtuellt Pick-by-Light system skulle kunna reducera implementerings-, arbetes- samt driftkostnader i och med att materialåtgången ersätts av en virtuell produkt, samt att ingen installation krävs. I och med kombinationen av Tangar finns det även potential att konceptet är mer effektivt och exakt. De nackdelar med det traditionella Pick-by-Light systemet är också att plock-bekräftelser görs ineffektivt och att arbetare har svårt att få en överblick gällande plockställen. Vilket skulle kunna elimineras med det föreslagna konceptet. Dock krävs en ny generation hårdvara och vidare studier för att kunna fastställa ett slutgiltigt koncept. Magic Leap One, som är den huvudmonterade skärmen som används i projektet är väldigt ny. Många problem gällande displayen har upptäckts under projektet och påverkat resultatet av användarstudierna. Fortsatta studier skulle behöva göras med andra displayer för att fastställa validiteten av resultaten från det här arbetet. Sammanfattningsvis ger det här arbetet en introduktion om hur ”Mixed-reality” kan användas inom lagerhantering samt rekommendationer till fortsatt arbete.

A virtual environment is a set of surroundings that appears to exist to a user through sensory stimuli provided by a computer. By virtual environment, we mean to include environments supporting the full range from VR to pure reality. A necessity for virtual environments is knowledge of the location of objects in the environment. This is referred to as the tracking problem, which points to the need for accurate and precise tracking in virtual environments. Marker-based tracking is a technique which employs fiduciary marks to determine the pose of a tracked object. A collection of markers arranged in a rigid configuration is called a tracking probe. The performance of marker-based tracking systems depends upon the fidelity of the pose estimates provided by tracking probes. The realization that tracking performance is linked to probe performance necessitates investigation into the design of tracking probes for proponents of marker-based tracking. The challenges involved with probe design include prediction of the accuracy and precision of a tracking probe, the creation of arbitrarily-shaped tracking probes, and the assessment of the newly created probes. To address these issues, we present a pioneer framework for designing conformal tracking probes. Conformal in this work means to adapt to the shape of the tracked objects and to the environmental constraints. As part of the framework, the accuracy in position and orientation of a given probe may be predicted given the system noise. The framework is a methodology for designing tracking probes based upon performance goals and environmental constraints. After presenting the conformal tracking framework, the elements used for completing the steps of the framework are discussed. We start with the application of optimization methods for determining the probe geometry. Two overall methods for mapping markers on tracking probes are presented, the Intermediary Algorithm and the Viewpoints Algorithm. Next, we examine the method used for pose estimation and present a mathematical model of error propagation used for predicting probe performance in pose estimation. The model uses a first-order error propagation, perturbing the simulated marker locations with Gaussian noise. The marker locations with error are then traced through the pose estimation process and the effects of the noise are analyzed. Moreover, the effects of changing the probe size or the number of markers are discussed. Finally, the conformal tracking framework is validated experimentally. The assessment methods are divided into simulation and post-fabrication methods. Under simulation, we discuss testing of the performance of each probe design. Then, post-fabrication assessment is performed, including accuracy measurements in orientation and position. The framework is validated with four tracking probes. The first probe is a six-marker planar probe. The predicted accuracy of the probe was 0.06 deg and the measured accuracy was 0.083 plus/minus 0.015 deg. The second probe was a pair of concentric, planar tracking probes mounted together. The smaller probe had a predicted accuracy of 0.206 deg and a measured accuracy of 0.282 plus/minus 0.03 deg. The larger probe had a predicted accuracy of 0.039 deg and a measured accuracy of 0.017 plus/minus 0.02 deg. The third tracking probe was a semi-spherical head tracking probe. The predicted accuracy in orientation and position was 0.54 plus/minus 0.24 deg and 0.24 plus/minus 0.1 mm, respectively. The experimental accuracy in orientation and position was 0.60 plus/minus 0.03 deg and 0.225 plus/minus 0.05 mm, respectively. The last probe was an integrated, head-mounted display probe, created using the conformal design process. The predicted accuracy of this probe was 0.032 plus/minus 0.02 degrees in orientation and 0.14 plus/minus 0.08 mm in position. The measured accuracy of the probe was 0.028 plus/minus 0.01 degrees in orientation and 0.11 plus/minus 0.01 mm in position. These results constitute an order of magnitude improvement over current marker-based tracking probes in orientation, indicating the benefits of a conformal tracking approach. Also, this result translates to a predicted positional overlay error of a virtual object presented at 1m of less than 0.5 mm, which is well above reported overlay performance in virtual environments.

<p>Upon introducing semi- and fully automated vehicles on the road, drivers will be reluctant to focus on the traffic interaction and rely on the vehicles' decision-making. However, encountering pedestrians still poses a significant difficulty for modern automated driving technologies. Considering the high-level complexity in human behavior modeling to solve a real-world problem, deep-learning algorithms trained from naturalistic data have become promising solutions. Nevertheless, although developing such algorithms is achievable based on scene data collection and driver knowledge extraction, evaluation remains challenging due to the potential crash risks and limitations in acquiring ground-truth intention changes. </p> <p><br></p> <p>This study proposes a VR-based testing bed to evaluate real-time pedestrian intention algorithms as VR simulators are recognized for their affordability and adaptability in producing a variety of traffic situations, and it is more reliable to conduct human-factor research in autonomous cars. The pedestrian wears the head-mounted headset or uses the keyboard input and makes decisions in accordance with the circumstances. The simulator has added a credible and robust experience, essential for exhibiting the real-time behavior of the pedestrian. While crossing the road, there exists uncertainty associated with pedestrian intention. Our simulator will anticipate the crossing intention with consideration of the ambiguity of the pedestrian behavior. The case study has been performed over multiple subjects in several crossing conditions based on day-to-day life activities. It can be inferred from the study outcomes that the pedestrian intention can be precisely inferred using this VR-based simulator. However, depending on the speed of the car and the distance between the vehicle and the pedestrian, the accuracy of the prediction can differ considerably in some cases.</p>

Night vision goggles (NVGs) are optical devices used to enhance human vision at low light conditions such as nighttime. The image seen through the goggles is brightened but with the consequence of introduced visual limitations and illusions. Because of this, fighter pilots need to undergo proper training with such equipment before operating with them in real-life. An NVG simulation within a Mixed Reality (MR) flight simulator can in theory be used to build the skills needed and directly translate them into real life. In this thesis, an NVG effect was added to a video see-through camera feed(VST) such that a whole NVG simulation could be experienced in an MR flight simulator. Furthermore, a method to seamlessly integrate the VST into the nocturnal virtual world was proposed. By conducting a semi structured interview with an NVG expert, the experienced realism, presence, and training value of the implemented effects were measured. A thematic analysis of the gathered interview data provided insight into the most important themes regarding NVG simulations within an MR flight simulator. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

The use of Virtual Reality (VR) in a variety of professional, military, governmental, and educational fields has continued to expand over the past several decades, and the recent Covid-19 pandemic has brought attention to this field. This study surveys 154 college students over 23 questions that include various demographics that can be used to look for discriminators, multiple-choice VR-related questions, as well as a few free-form questions about use of VR in learning environments. The students’ experience with, interest in, and thoughts on how to best use VR vary considerably. The Covid-19 pandemic is found to have limited impact thus far in terms of VR use, but the interest in using VR in schools since then has generally increased quite a bit. Commitment to invest in VR were it to be expanded and provide continual feedback varies quite a bit as well but is strong. A statistical 2 analysis shows that, at a high confidence level, males generally are more experienced with VR in general, have a greater interest in seeing VR implemented further, and are more committed to radical changes in educational methodology than females are. In addition, it is found that Hispanics/Latinos, Black / African Americans, Pacific Islanders, and those of mixed race are more inclined to provide continual feedback as regards the implementation of VR in the school curriculum than (non-Hispanic) White and Asian people are.

Fundamentally, interaction design is about getting in between: Between people and what is important to them. While it often makes sense to make mediated interactions explicit, implicit interactions can integrate harmoniously into the here and now and happen almost unnoticed. In this master’s thesis, I explore different approaches to harmoniously integrate interactions with mobile and wearable devices into cycling. Cycling can be treated as a modality. It can influence the behaviour of the operating system or provide considerations for the design of applications. Rather than adding to the existing flow of signals, I propose to tap into that flow and even take it a step further: I explore ways to add meaning to what people are already doing as if there were no interface. Wearable devices, such as the current Apple Watch, can provide comprehensive insight into ongoing activities. The name "smartwatch" suggests that this device is meant to be attended to, but the greater opportunity lies in sensing and adding meaning to what is already happening. This allows people to immerse themselves in their ‘natural’ environment with their heads up and their hands free.

<p>The use of lower airspace for air taxi and cargo applications opens up exciting prospects for futuristic Unmanned Aircraft Systems (UAS). However, ensuring the safety and security of these UAS within densely populated urban areas presents significant challenges. Most modern aircraft systems, whether unmanned or otherwise, rely on the Global Navigation Satellite System (GNSS) as a primary sensor for navigation. From satellite navigations point of view, the dense urban environment compromises positioning accuracy due to signal interference, multipath effects, etc. Furthermore, civilian GNSS receivers are susceptible to spoofing attacks since they lack encryption capabilities. Therefore, in this thesis, we focus on examining the safety and cybersecurity assurance of UAS in dense urban environments, from both theoretical and experimental perspectives. </p> <p>To facilitate the verification and validation of the UAS, the first part of the thesis focuses on the development of a realistic GNSS sensor emulation using a Gazebo plugin. This plugin is designed to replicate the complex behavior of the GNSS sensor in urban settings, such as multipath reflections, signal blockages, etc. By leveraging the 3D models of the urban environments and the ray-tracing algorithm, the plugin predicts the spatial and temporal patterns of GNSS signals in densely populated urban environments. The efficacy of the plugin is demonstrated for various scenarios including routing, path planning, and UAS cybersecurity. </p> <p>Subsequently, a robust state estimation algorithm for dynamical systems whose states can be represented by Lie Groups (e.g., rigid body motion) is presented. Lie groups provide powerful tools to analyze the complex behavior of non-linear dynamical systems by leveraging their geometrical properties. The algorithm is designed for time-varying uncertainties in both the state dynamics and the measurements using the log-linear property of the Lie groups. When unknown disturbances are present (such as GNSS spoofing, and multipath effects), the log-linearization of the non-linear estimation error dynamics results in a non-linear evolution of the linear error dynamics. The sufficient conditions under which this non-linear evolution of estimation error is bounded are derived, and Lyapunov stability theory is employed to design a robust filter in the presence of an unknown-but-bounded disturbance. </p>

Increasing the environmental awareness of invisible data, such as a city’s air pollution or a household’s energy consumption, has been an ongoing information visualization challenge that has entered the fields of immersive technologies like augmented (AR) and mixed reality (MR). In order to understand how form and dimensional affect this understanding for MR environments, this research investigated what the difference between statistical, iconographic 2D and physical 3D visualizations is with regards to minimizing cognitive load and fostering environmental awareness. By following a HCD process, two MR prototypes were developed for the HoloLens 2 which depicted invisible gas leak data. They were evaluated through a survey and usability study with 14 experts and non-experts, using SAGAT, NASA-TLX and other questionnaires. The results suggest that there is no significant difference between statistical, iconographic 2D and physical 3D visualizations in terms of environmental awareness and cognitive load. However, an analysis of the effect size and qualitative post-interview data imply that the physical 3D visualization led to a higher environmental awareness in all its three dimensions, while an analysis of the cognitive load sub-dimensions indicate that the statistical, iconographic 2D visualization was better suited for lowering cognitive load. / Att öka medvetenheten om osynliga data, såsom luftförororeningar i en stad eller hushållens energiförbrukning, har varit en pågående utmaning inom informationsvisualisering som har nått fram till områden inom immersiva teknologier som förstärkt verklighet (AR) och blandad verklighet (MR). För att förstå hur form och dimension påverkar denna förståelse i MR-miljöer, undersökte denna forskning skillnaden mellan statistiska, ikonografiska 2D- och fysiska 3D-visualiseringar när det gäller att minska kognitiv belastning och främja miljömedvetenhet. Genom att följa en HCD-process utvecklades två MR-prototyper för HoloLens 2 som skildrade osynliga gasläckagedata. De utvärderades genom en enkät- och användbarhetsstudie med 14 experter och icke-experter, där SAGAT, NASA-TLX och andra enkäter användes. Resultaten antyder att det inte finns någon signifikant skillnad mellan statistiska, ikonografiska 2D- och fysiska 3D-visualiseringar när det gäller miljömedvetenhet och kognitiv belastning. Dock antyder en analys av effektstorleken och kvalitativa postintervjudata att den fysiska 3D-visualiseringen ledde till en högre miljömedvetenhet i alla sina tre dimensioner, medan en analys av underdimensionerna för kognitiv belastning indikerar att den statistiska, ikonografiska 2D-visualiseringen var bättre lämpad för att minska kognitiv belastning.

Elevated heart rate is considered to be an indicator of stress. Thus, noticing one’s own heartbeat can have a negative connotation. Yet, the heartbeat is simply a physiological function, neither positive nor negative in itself, that is experienced in diverse contexts, such as medical, athletic, or intimate. This study uses first-person  research through design and soma design to increase awareness of the heartbeat from both an individual and social angle and examines the potential benefits of using external sensory stimuli to convey biofeedback information. It also opens up the design space around the heartbeat and sensory stimuli and reflects upon comfort and relaxation, biofeedback and digital mindfulness, the Sensiks sensory reality pod as a tool and space, and the heartbeat as a spectrum and a way of getting to know people. The study results in four deliverables: a design critique of the Sensiks sensory reality pod, a design fiction publication, a design proposal, and an experience prototype. The study proposes the design for the Gallery of Heartbeats – a sensory experience aimed at externalising and sharing the heartbeat of self and others. The Gallery of Heartbeats supports individual reflections, providing the user with real-time numerical, graphical, and auditory biofeedback on their heart rate. It also encourages social communication of this commonly unnoticed physiological feature, allowing users to record and store their heartbeat to an archive and experience the pre-recorded heartbeats of others in a multisensory way. The evaluation of the Gallery of Heartbeats prototype shows that the design succeeds in making people more aware of their cardiovascular activity, triggers their curiosity, and increases empathy. However, the Gallery of Heartbeats also makes the users want to control or change their heart rate which goes against the mindfulness principles of presence-in and presence-with the design was inspired by. Sensory stimuli, especially sound and visuals, are assessed as beneficial for creating feelings of immersion, whereas different representations of the biofeedback information have different effects and use cases. / En förhöjd hjärtfrekvens anses vara en indikator på stress. Därför kan en hög puls tolkas som något negativt. Likväl har hjärtats pulserande enbart en fysiologisk funktion, som i sig varken har en positiv eller negativ betydelse, och som kan erfaras under olika omständigheter, såsom i medicinska sammanhang, vid fysisk träning eller under intima stunder.  Denna studie är en forskning-genom-design ur ett förstapersonsperspektiv samt soma-design för att öka medvetenheten om sina hjärtslag, både från en individuell och en social vinkel, samt en undersökning av de potentiella fördelar som kan finnas med att använda ett yttre stimuli för att ge biofeedback. Den öppnar också upp designrymden kring hjärtslag och sensorisk stimuli, reflekterar kring välbefinnande och avslappning, biofeedback och digital mindfulness, Sensiks sensoriska kapsel som ett verktyg och en plats, samt hjärtfrekvens som ett spektrum och ett sätt att lära känna människor. Resultatet av studien framställs i fyra olika delar: en designkritik av Sensiks sensoriska kapsel, en fiktiv design publikation, ett designförslag, och en prototyp av upplevelser. Detta examensarbete utmynnar i ett förslag på en design kallad “Gallery of Heartbeats” - en sensorisk upplevelse avsedd att ge en yttre form och för att dela hjärtslagen med sig själv och andra. “Gallery of Heartbeats” skapar utrymme för individuell reflektion, och ger användaren i realtid en numerisk, grafisk och ljudmässig biofeedback på sin hjärtfrekvens. Den uppmuntrar också till samtal av detta vanligtvis omärkbara fysiologiska fenomen, den möjliggör användaren att spela in och spara sina hjärtslag i ett arkiv, och användaren ges möjlighet att uppleva förinspelade hjärtslag av andra personer på ett multisensoriskt sätt. Utvärdering av prototypen för “Gallery of Heartbeats” visar att designen lyckas få människor mer medvetna om sin kardiovaskulära aktivitet, väcker deras nyfikenhet och ökar empatin. Dock gör även “Gallery of Heartbeats” att användaren vill kontrollera eller ändra sin hjärtfrekvens, vilket går emot de principerna inom mindfulness av att vara ‘presence-in’ och ‘presence-with’. Sensorisk stimuli, särskilt ljud och bild, ses som främjande av att skapa känslan av att vara absorberad, medan andra signaler från biofeedback har en annan påverkan och andra användningsområden.