Augmented Reality (AR) head-mounted display (HMD) provides users with an immersive virtual experience in the real world. The portability of this technology affords various information display options for construction workers that are not possible otherwise. The information delivered via an interactive user interface provides an innovative method to display complex building instructions, which is more intuitive and accessible compared with traditional paper documentations. However, there are still challenges hindering the practical usage of this technology at the construction jobsite. As a technical restriction, current AR HMD products have a limited field of view (FOV) compared to the human vision range. It leads to an uncertainty of how the obstructed view of display will affect construction workers' perception of hazards in their surrounding area. Similarly, the information displayed to workers requires rigorous testing and evaluation to make sure that it does not lead to information overload. Therefore, it is essential to comprehensively evaluate the impacts of using AR HMD from both perspectives of task performance and cognitive performance. This dissertation aims to bridge the gap in understanding the cognitive impacts of using AR HMD in construction assembly tasks. Specifically, it focuses on answering the following two questions: (1) How are task performance and cognitive skills affected by AR displays under complex working conditions? (2) How are moment-to-moment changes of mental workload captured and evaluated during construction assembly tasks? To answer these questions, this dissertation proposed two experiments. The first study tests two AR displays (conformal and tag-along) and paper instruction under complex working conditions, involving different framing scales and interference settings. Subjective responses are collected and analyzed to evaluate overall mental workload and situation awareness. The second study focuses on exploring an electroencephalogram (EEG) based approach for moment-to-moment capture and evaluation of mental workload. It uncovers the cognitive change on the time domain and provides room for further quantitative analyzing on mental workload. Especially, two frameworks of mental workload prediction are proposed by using (1) Long Short-Term Memory (LSTM) and (2) one-dimensional Convolutional Neural Network (1D CNN)-LSTM for forecasting EEG signal and, classifying task conditions and mental workload levels respectively. The approaches are tested to be effective and reliable for predicting and recognizing subjects' mental workload during assembly. In brief, this research contributes to the existing knowledge with an assessment of AR HMD use in construction assembly, including task performance evaluation and both subjective and physiological measurements for cognitive skills. / Doctor of Philosophy / Augmented Reality (AR) is an emerging technology that bridges the gap between virtual creatures and physical world with an immersive display experience. Today, head-mounted display (HMD) is well developed to meet the demands for portable AR devices. It provides interactive and intuitive display of 2D graphical information to make it easier to understand for users. Therefore, AR display has been studied in the past few years for a more simplified and productive construction assembly process. However, given the premise that construction is a high-risk industry, introducing such display technology to the jobsite needs to be carefully tested. One obstacle in current AR HMD products is the restriction of field of view (FOV), which may block users' view in presenting large-scale 3D objects. In construction assembly, workers need to deal with tasks in different scopes, such as wood framing for a residential house. Consequently, it is necessary to study how such technical challenge will impact workers' performance under different task conditions. Another concern comes from the mental perspective. Although AR display may bring convenience in acquiring effective information, it is difficult to measure if this generates excessive mental burden to users. Especially for construction workers, whether the overlaid display will cause distraction and information overload is crucial for protecting workers from hazards. To address the problems, this dissertation explores the gap in previous literature, where mental workload is not well studied for using AR HMD in construction assembly. Two experiments are conducted to comprehensively evaluate the impacts of AR displays on both assembly performance and users' mental status. The outcomes bring implications to theoretical and practical aspects. First, it compares two AR displays (2D tag-along image and 3D conformal model) with traditional paper documentation for assembly performance (efficiency and accuracy) and users' cognitive skills (mental workload and situation awareness). The findings revealed the impact of FOV restriction and provided a strategic solution to selecting display method for different task conditions. Second, it proposes a physiological approach to calculate mental workload from analyzing the features from brain waves. It uncovered the latent mental changes during the assembly. Furthermore, two deep learning approaches are applied to predict and classify mental workload. The prediction model depicted the trend of mental workload in eighteen seconds based on an eighty-four-second training set, while the classifier recognized two task conditions with different mental workload levels with an accuracy of 93.6%. The results have promising potential for future research in detecting and preventing abnormality in workers' mental status. In addition, it is generalizable to apply in other construction tasks and AR applications.

A interstep between a regular car and a fully self-driving car is a teleoperated car, where the driver controls the car remotely in situations that the self-driving AI isn't equipped to handle. The cognitive load of regular driving is known, and how long it's safe to drive without taking a rest, but it has not been that well explored when it comes to teleoperated driving. This paper examines which screen set-up would be preferable for the operator to use, comparing the cognitive load while using a driving simulator on a conventional computer screen and a head mounted display. The data that was able to be analyzed points to there not being any noticeable difference between the two in terms of cognitive load, but the participants noted the HMD has several advantages over the conventional screen. Despite this, the majority of the participants preferred the conventional screen due to cybersickness and discomfort from the HMD. / Ett mellansteg mellan en vanlig bil och en helt självkörande bil är en fjärrstyrd bil, där föraren fjärrstyr bilen i situationer som den självkörande AIn inte kan klara av. Vi vet hur stor den mentala belastningen är när det gäller vanlig bilkörning, och vi vet hur länge det är säkert att köra utan att behöva ta rast, men när det gäller fjärrstyrda bilar har detta inte undersökts så mycket. Den här rapporten undersöker vilken form av skärm som skulle vara att föredra att använda, genom att jämföra den mentala belastningen mellan en vanlig datorskärm och VR glasögon när man använder en bilsimulator. Resultatet pekar på att det inte var någon märkbar skillnad mellan de två alternativen när det gäller mental belastning, men deltagarna noterade att VR glasögonen hade flera fördelar över den vanliga datorskärmen. Trots detta så föredrog majoriteten av deltagarna att använda den vanliga skärmen då VR glasögonen gav dem åksjuka och var obekväm.

An important aspect concerning all Virtual Reality (VR) applications is to not induce cybersickness. Literature is suggesting that cybersickness and the sense of “presence” in VR are two inversely related factors. This thesis has investigated this relationship by developing a VR environment in three versions, designed to induce different amounts of presence in users. These three versions have been tested by users in an experiment and evaluated through the Simulator Sickness Questionnaire (SSQ) and the Igroup Presence Questionnaire (IPQ).

Research has shown that head-mounted displays can produce greater presence in a virtual environment than direct-view displays. It has also been shown that after vision, haptic response is one of the most important inputs for humans in a simulated environment. This research was designed primarily to determine the performance differences associated with different display types, levels of steering force feedback, and the interaction between these two factors in a low-to-medium fidelity, PC-based driving simulator. Participants drove on a simulated driving course during which both objective driving performance data were collected (lane deviation, speed control, steering wheel angle variance, and time to the complete course) as well as subjective self-report measures including questionnaires designed to tap immersive tendencies and perceived levels of presence. Results of the research show that the use of a head-mounted display can significantly impact driving performance in terms of speed control and lane deviation. Speed control was significantly improved (increased) and lane deviation was significantly improved (decreased) in three of the four roadway segments with the use of an HMD. Results for active steering force feedback, however, showed a significantly negative effect on driving performance with an increase in average lane deviation. Descriptive statistics showed that participants preferred the HMD and D-V equally and all but one participant preferred active steering force feedback. / Master of Science

When talking about how to present information in virtual reality, the possibilities are countless, but there are also many problems surrounding the spatial location of the information. This study aims to examine where and how the instructions in a vehicle training simulator should be presented in a future implementation of the interface in virtual reality. To find this out, a gameplay was created in which four different placements of the instructions were made. Three options were based on earlier studies made by Smith (2015) and Jose (2016) and the fourth was based on the existing information in the vehicle training simulator. These gameplays were presented as a movie to a number of interviewees and followed up by questions after each movie. The interviewees were asked to give the movies three ratings from 1-5, valuing how they perceived the presentation of the instructions. To get further opinions, comments was collected from the interviewees throughout each session. In this two ways, we got answers to which of the four options the interviewees thought was best. The study showed that there were two options that stood out among the others and both were based on the concept of a head-up display, also known as a HUD. One was represented in the bottom of the windshield and the other one in the top. The result of which one of them who were perceived as best is too close to say, although the study is considered to have reached its goal, which was to help the developers on their way to a decision that will eventually be implemented.

In der Produktentwicklung nimmt die Bedeutung von Head-Mounted-Displays (HMD) stetig zu. Mit HMDs ist es möglich, virtuelle Objekte zu betrachten und mit diesen in realem oder virtuellen Kontext zu interagieren. Die Entwicklung von HMDs im Entertainment-Bereich und die nativen Augmented-Reality(AR)-Funktionen von Smartphones und Tablets (Apple Inc. 2019, Google Inc. 2019) machen AR- und Virtual-Reality(VR)-Anwendungen einer breiten Nutzerbasis zugänglich. Die individuelle Entwicklung dieser Anwendungen ist mit heutigen Software-Werkzeugen umfangreich möglich. Im Bereich der Produktentwicklung und Schulung werden die Geräte ebenfalls genutzt, bedürfen jedoch intensiver Erforschung und Anpassung an individuelle Bedürfnisse. Besondere Anforderungen kommen auf AR- und VR-Systeme zu, wenn Nutzende kollaborieren möchten. Anders als im Entertainment-Bereich spielen hier die Genauigkeit der Sensorik, eine konsistente Wahrnehmung aller Teilnehmenden und Möglichkeiten zur Vermittlung von Ideen und Anmerkungen eine tragende Rolle. Als Werkzeug für einen solchen Gedankenaustausch werden neben verbaler Kommunikation und Textverkehr meist Annotationen genutzt. Bedingt durch gerätespezifische Eingabemethoden müssen Annotationssysteme und Annotationen in AR und VR anders gestaltet werden als in klassischen Desktopanwendungen. In einem Review erzeugte Annotationen beinhalten wichtige Informationen, die in den Entwicklungsprozess integriert werden müssen. Dementsprechend bedarf es einer Möglichkeit, Annotationen auch nach dem Review verwenden zu können. Diese verschiedenen Aspekte der Kollaboration sollen im Folgenden näher untersucht werden, um wichtige Erkenntnisse für den Einsatz von HMDs als Basis einer kollaborativen Umgebung zu vermitteln. [... aus der Einleitung]

The main aim of this thesis was to evaluate the performance of the contrast sensitivity clock (CSC), a new screening device for measuring contrast sensitivity (CS) and glare. This device allows CS without glare, with glare and disability glare scores to be recorded. After initial data collection the design of the CSC was slightly amended improving the performance of the device. The amended design of the CSC was shown to be a valid, discriminative and repeatable measure for purpose. The CSC is also a quick test to perform and is relatively cheap to produce. If all these factors are considered it shows potential to become the test of choice for the assessment of visual glare. A head-mounted display system was also evaluated in terms of the glare effects it may cause. The monocular display screen of the device significantly reduced the CS of the eye directly exposed but also had an effect on binocular performance, reducing amounts of binocular summation. Electronic devices, including head-mounted displays and satellite navigation systems can seriously affect CS at low luminance levels, similar to those found when driving at night.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T17:46:30Z No. of bitstreams: 1 AlysonMatheusDeCarvalhoSouza_DISSERT.pdf: 5735657 bytes, checksum: e01d871f402904e1e865bcf5257146d3 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-27T22:06:43Z (GMT) No. of bitstreams: 1 AlysonMatheusDeCarvalhoSouza_DISSERT.pdf: 5735657 bytes, checksum: e01d871f402904e1e865bcf5257146d3 (MD5) / Made available in DSpace on 2016-01-27T22:06:43Z (GMT). No. of bitstreams: 1 AlysonMatheusDeCarvalhoSouza_DISSERT.pdf: 5735657 bytes, checksum: e01d871f402904e1e865bcf5257146d3 (MD5) Previous issue date: 2014-09-25 / A percep??o correta de dist?ncias ? importante para a execu??o de diversas tarefas interativas, como navega??o, sele??o e manipula??o. ? sabido, no entanto, que, em geral, existe uma significativa compress?o das dist?ncias percebidas em ambientes virtuais, principalmente quando h? a utiliza??o de Head-Mounted Displays - HMDs. Essa compress?o de dist?ncias percebidas pode trazer ? aplica??o diversos problemas e at? afetar negativamente a utilidade de aplica??es que dependem desse julgamento correto. A comunidade cient?fica, at? o presente, n?o conseguiu determinar as causas do fen?meno da compress?o da percep??o de dist?ncia em ambientes virtuais. Por esse motivo, foi o objetivo desse trabalho buscar, atrav?s de experimentos com usu?rios, encontrar pistas sobre a influ?ncia do field-of-view - FoV - e dos m?todos para estimativas de dist?ncias nessa compress?o percebida. Para tal, foi feita uma compara??o experimental entre o my3D e o HMD, utilizando 32 participantes, a fim de encontrar pistas sobre as causas da percep??o comprimida. Os resultados indicaram que o my3D possui capacidades inferiores ao HMD, produzindo estimativas piores, em m?dia, em ambos os m?todos de estimativa testados. As causas apontadas para tal foram o est?mulo incorreto da vis?o perif?rica, o FoV inferior e a menor imers?o, segundo descrito pelos participantes do experimento / The correct distance perception is important for executing various interactive tasks such as navigation, selection and manipulation. It is known, however, that, in general, there is a significant distance perception compression in virtual environments, mainly when using Head-Mounted Displays - HMDs. This perceived distance compression may bring various problems to the applications and even affect in a negative way the utility of those applications that depends on the correct judgment of distances. The scientific community, so far, have not been able to determine the causes of the distance perception compression in virtual environments. For this reason, it was the objective of this work to investigate, through experiments with users, the influence of both the field-of-view - FoV - and the distance estimation methods on this perceived compression. For that, an experimental comparison between the my3D device and a HMD, using 32 participants, seeking to find information on the causes of the compressed perception, was executed. The results showed that the my3D has inferior capabilities when compared to the HMD, resulting in worst estimations, on average, in both the tested estimation methods. The causes of that are believed to be the incorrect stimulus of the peripheral vision of the user, the smaller FoV and the smaller immersion sense, as described by the participants of the experiment.

Virtuell verklighet (VR) har under de senaste åren fått en uppsving i popularitet. Rörelsesjuka i VR har länge varit ett problem och är idag fortfarande ett stort hinder för kommersiell succé. Detta arbete ämnar till att implementera stöd för Oculus Rift i programmet Configura, och utvärdera navigering med handkontroll i en VR-miljö. Fokuset ligger på att hitta lämpliga gång- och rotationshastigheter för effektiv navigering med handkontroll, och effekten hastigheterna har på rö- relsesjuka. En användarstudie genomfördes där personer testade olika gång- och rotationshastigheter i olika tester med ökande svårighetsgrad i navigering. Resultaten från användarstudien visar på att i alla hastigheter upplevde testpersonerna allvarliga symptom av rörelsesjuka. Det fanns även indikationer att användare med lägre hastigheter presterar bättre. / Virtual Reality (VR) have risen in popularity during the last years. Motion sickness however have been a big problem and still is an obstacle for commercial success. This thesis work aims to implement VR-support in the space planning program Configura, and evaluate navigation with a controller in a VR-environment. The focus of this study is to find suitable walking and rotational speeds for effective navigation with a controller, and the effects different speeds have on motion sickness. A user study was preformed where users tested different speeds in tests with an increasingly difficulty in navigation. The results from the study shows that people had severe symptoms of motion sickness in all speeds. There were also indications that lower speeds made people perform better.

This master's thesis is dealing with the usage of augmented reality for a layout of a flat proposition. The aim of this work is to create a system which detects markers on the walls using ARToolKit library. The position of the used in flat is determined by using the markers. Then the system disposes the user's position for operate with a camera in a 3D modelling program called Google SkretchUp. The system is consisted of a server and a client part. The server one copes with the incoming video in which it detects the markers and evaluates the position of user by the help of the markers. The client part of the system is represented by a plugin module for 3D modelling program Google SkretchUp. A client is asking the server for the positions of the user in the flat model and consequently he set the camera in the program Google SkretchUp according to these positions. The client is also asking for the individual pictures from the video which he shows against the background of Google SketchUp and thanks to this, he creates a view of a real scene extended of virtual objects.