From sensory substitute technology to virtual reality research

This paper describes research into sensory substitutes for the disabled, and proposes one basic research approach to assistance technology. It also reports on how the technology is related to virtual reality research.     

虚拟现实技术在数字化校园中的应用

继多媒体、计算机网络之后,虚拟现实技术成为在教育领域内最具有应用前景的技术。随着该技术的不断发展,它在数字化校园的建设与应用中将发挥其特有的优势。本文将从虚拟现实技术的概念及特点出发,进一步探讨虚拟现实技术在数字化校园中的具体应用。     

Advanced teleoperation and control system for industrial robots based on augmented virtuality and haptic feedback

There are some industrial tasks that are still mainly performed manually by human workers due to their complexity, which is the case of surface treatment operations (such as sanding, deburring, finishing, grinding, polishing, etc.) used to repair defects. This work develops an advanced teleoperation and control system for industrial robots in order to assist the human operator to perform the mentioned tasks. On the one hand, the controlled robotic system provides strength and accuracy, holding the tool, keeping the right tool orientation and guaranteeing a smooth approach to the workpiece. On the other hand, the advanced teleoperation provides security and comfort to the user when performing the task. In particular, the proposed teleoperation uses augmented virtuality (i.e., a virtual world that includes non-modeled real-world data) and haptic feedback to provide the user an immersive virtual experience when remotely teleoperating the tool of the robot system to treat arbitrary regions of the workpiece surface. The method is illustrated with a car body surface treatment operation, although it can be easily extended to other surface treatment applications or even to other industrial tasks where the human operator may benefit from robotic assistance. The effectiveness of the proposed approach is shown with several experiments using a 6R robotic arm. Moreover, a comparison of the performance obtained manually by an expert and that obtained with the proposed method has also been conducted in order to show the suitability of the proposed approach.     

Peltier Haptic Interface (PHI) for improved sensation of touch in virtual environments

In this report we describe an advanced virtual reality glove that we are developing, called the Peltier Haptic Interface (PHI), which will provide improved sensation of touch in virtual environments. PHI will provide force/pressure feedback that can be varied independently on each finger, as well as temperature sensation that can be varied non-uniformly over the whole hand. The combination of these sensations will provide a more realistic sense of touch and significantly increase the realism of virtual environments. PHI will find extensive applications in biomedical simulations, teaching, industrial line training, and many other areas.     

A research agenda for augmented and virtual reality in architecture,engineering and construction

This paper presents a study on the usage landscape of augmented reality (AR) and virtual reality (VR) in the architecture, engineering and construction sectors, and proposes a research agenda to address the existing gaps in required capabilities. A series of exploratory workshops and questionnaires were conducted with the participation of 54 experts from 36 organisations from industry and academia. Based on the data collected from the workshops, six AR and VR use-cases were defined: stakeholder engagement, design support, design review, construction support, operations and management support, and training. Three main research categories for a future research agenda have been proposed, i.e.: (i) engineering-grade devices, which encompasses research that enables robust devices that can be used in practice, e.g. the rough and complex conditions of construction sites; (ii) workflow and data management; to effectively manage data and processes required by AR and VR technologies; and (iii) new capabilities; which includes new research required that will add new features that are necessary for the specific construction industry demands. This study provides essential information for practitioners to inform adoption decisions. To researchers, it provides a research road map to inform their future research efforts. This is a foundational study that formalises and categorises the existing usage of AR and VR in the construction industry and provides a roadmap to guide future research efforts.     

计算机虚拟现实技术的教学应用与软件的开发研究

提出了利用虚拟现实技术开发的"模拟法庭教学软件",建设<模拟法庭>虚拟实验室,以解决"模拟法庭"数量不足的问题,使每一个学生都参与到实践教学中去,教学效果良好.     

Semiotics of virtual reality as a communication process

ABSTRACT

The experience of immersive virtual reality (VR) can be considered as a communication process between human beings, mediated by computer systems, which uses visualisation and other sensory stimulation. In this paper, we analyse how VR characteristics can be explored using semiotic theory and, with methods of generative semiotics, we explore aspects of narrative and interaction in VR. We propose a semiotic analysis of VR communication focusing on syntax, semantics and pragmatics and considering also some principles of generative semiotics. The syntactic level is analysed as determined by the characteristics of the visual communication adopted. The semantic of VR is related to the functional model chosen to realise the virtual system. The pragmatic of VR is based on the human–computer interaction that changes the user's role. We explore how these aspects can be characterised in the context of VR communication design and what principles can be adopted for a VR application, and we present an analysis and a classification of the iconic signs that are being used in VR. Moreover, we present a framework that can be used to classify and describe different kinds of virtual reality systems and to better understand communication in VR, and we use it to classify eight popular systems for e-learning and collaboration.     

Tangible authoring of 3D virtual scenes in dynamic augmented reality environment

This paper proposes tangible interfaces and interactions for authoring 3D virtual and immersive scenes easily and intuitively in tangible augmented reality (AR) environment. It provides tangible interfaces for manipulating virtual objects in a natural and intuitive manner and supports adaptive and accurate vision-based tracking in AR environments. In particular, RFID is used to directly integrate physical objects with virtual objects and to systematically support the tangible query of the relation between physical objects and virtual ones, which can provide more intuitive tangibility and a new way of virtual object manipulation. Moreover, the proposed approach offers an easy and intuitive switching mechanism between tangible environment and virtual environment. This paper also proposes a context-adaptive marker tracking method which can remove an inconsistent problem while embedding virtual objects into physical ones in tangible AR environments. The context-adaptive tracking method not only adjusts the locations of invisible markers by interpolating the locations of existing reference markers and those of previous ones, but also removes a jumping effect of movable virtual objects when their references are changed from one marker to another. Several case studies for generating tangible virtual scenes and comparison with previous work are given to show the effectiveness and novelty of the proposed approach.     

Absorption,dissociation, locus of control and presence in virtual reality

The present study aimed to explore the relationship between a number of psychological variables and a reported sense of presence in immersive virtual reality (IVR). It was hypothesised that participants’ scores on measures of absorption, dissociation, and external locus of control would be positively and significantly correlated with a measure of their sense of presence in IVR. A total of 64 people took part. Significant correlations were found between presence and dissociation (r = 0.403, p < 0.01), and presence and locus of control (r = 0.268, p < 0.05). However, the correlation between presence and absorption was not significant (r = −0.037, p = 0.386). The findings reported here suggest a complex interrelationship of psychological variables in relation to presence in IVR that warrants further research.     

Two-handed assembly with immersive task planning in virtual reality

Assembly modelling is the process of capturing entities and activity information related to assembling and assembly. Currently, most CAD systems have been developed to ease the design of individual components, but are limited in their support for assembly designs and planning capability, which are crucial for reducing the cost and processing time in complex design, constraint analysis and assembly task planning. This paper presents a framework of a two-handed virtual assembly (VA) planner for assembly tasks, which coordinates two hands jointly for feature-based manipulation, assembly analysis and constraint-based task planning. Feature-based manipulation highlights the important assembling features (e.g. dynamic reference frames, moving arrow, mating features) to guide users for the ease of assembly and in an efficient and fluid manner. The users can freely navigate and move the mating pair along the collision-free path. The free motion of two-handed input in assembly is further restricted to the allowable motion guided by the constraints recognised on-line. The allowable motion in assembly is planned by the logic steps derived from the analysis of constraints and their translation in the progress of assembly. No preprocessing or predefined assembly sequence is necessary since the planning is produced in real-time upon the two-handed interactions. Mating features and constraints in databases are automatically updated after each assembly to simplify the planning process. The two-handed task planner has been developed and experimented for several assembly examples including a drill (12-parts) and a robot (17-parts). The system can be generally applied for the interactive task planning of assembly-type applications.     

Transfer of training from virtual reality

This experiment compared the value of real-world training, virtual reality training, and no training in the transfer of learning to the same task performed in real-world conditions. Results provide no evidence of transfer from a virtual reality training environment to a real-world task. There was no significant difference between the virtual reality training group and the group that received no training on the task. The group that received real-world training performed significantly better than both of the other two groups. The results question the utility of virtual training and suggest that in the present configuration, individuals learn performance characteristics specific only to the virtual reality context. Needed improvements to virtual reality for the purpose of enabling the transfer of training are indicated.     

Using virtual reality to determine how emergency signs facilitate way-finding

In this study, virtual reality was the tool used to construct an experimental space. Three scenarios - one without emergency signs, another with an old-version emergency sign, and the third with a new-version emergency sign - were created, after which 107 subjects, divided into three groups, engaged in an emergency escape game to determine if and how various emergency signs aid in way-finding in the event of an emergency. Under the presupposition that the minimum time needed for an emergency escape without any mistake occurring was 40 s, we found that the average way-finding time in the scenario without any emergency signs was 123.8 s, for the scenario with the new-version signs 84.8 s, and for the scenario with the old-version signs 75.6 s; statistically, this demonstrated that the absence of signs results in slower escape than either old signs (p = 0.001) or new signs (p = 0.005). These findings indicate that signs do help way-finding greatly. Males were found to exhibit better way-finding skills than females (p < 0.001). Construction workers and fire safety personnel, as a combined group, did not fare better than others with less presumed prior experience with building plans or emergency exit procedures. In addition, when faced with both an emergency direction sign and an exit door, almost half of the subjects (42% of the participants) were chosen to take the door instead of following the direction posted on the sign. Finally, we found that, at T-intersections, the majority of participants (60%) chose to turn left versus right.     

The input-interface of Webcam applied in 3D virtual reality systems

Our research explores a virtual reality application based on Web camera (Webcam) input-interface. The interface can replace with the mouse to control direction intention of a user by the method of frame difference. We divide a frame into nine grids from Webcam and make use of the background registration to compute the moving object. In order to make this technology apply to 3D virtual reality system, we use the Virtools Dev to build virtual scenes and the Microsoft Visual C++ to build this interface. We also use the MySQL database management system to access users’ data and the displaying data. We implement a number of Building Blocks (BB) to support Virtools Dev for using the database management system and the Webcam input-interface in this composite system. The results of research are expected to the digital content industries such that users can easy to use the input-interface to control browsing the virtual reality. Our system can supply interactive digital content, photographs, and access the questions from the database management system. In addition, the system provides the browsing mold, the question mold, and the course content describing mold with the input-interface. In order to explore the intention of users for using the system, we design the questionnaire based on the technology acceptance model (TAM). In our empirical study, we find that perceived playfulness is positive association with attitude toward using. Interface style is positive association with perceived ease of use.     

Experiencing immersive virtual reality in museums

Virtual Reality (VR) has been regarded as a highly effective technology that enables people to gain enjoyable and immersive information about museum collections. Drawing from the four realms of the experience economy, we assume absorptive experiences influence immersive experiences, overall museum VR tour experience, and intention to visit a museum. The results show that all the hypotheses are supported. Furthermore, we compared and tested the proposed model and its rival model (postulating the direct influence of the four realms of the experience economy on museum VR experience) and found that the proposed model is better than the rival model.     

基于虚拟现实技术的移动机器人视觉伺服控制系统设计

为了有效确保移动机器人视觉伺服控制效果,提高移动机器人视觉伺服控制精度,设计了基于虚拟现实技术的移动机器人视觉伺服控制系统。通过三维视觉传感器和立体显示器等虚拟环境的I/O设备、位姿传感器、视觉图像处理器以及伺服控制器元件,完成系统硬件设计。从运动学和动力学两个方面,搭建移动机器人数学模型,利用标定的视觉相机,生成移动机器人实时视觉图像,通过图像滤波、畸变校正等步骤,完成图像的预处理。利用视觉图像,构建移动机器人虚拟移动环境。在虚拟现实技术下,通过目标定位、路线生成、碰撞检测、路线调整等步骤,规划移动机器人行动路线,通过控制量的计算,实现视觉伺服控制功能。系统测试结果表明,所设计控制系统的位置控制误差较小,姿态角和移动速度控制误差仅为0.05°和0.12m/s,移动机器人碰撞次数较少,具有较好的移动机器人视觉伺服控制效果,能够有效提高移动机器人视觉伺服控制精度。     

Application of virtual reality in hospital facilities design

The airborne particles present in certain hospital environments, such as the tuberculosis isolation or operating rooms, can be extremely harmful for patients and/or hospital personnel. An important issue during the design of hospital facilities is an efficient airborne particle removal system. A near-optimal setup of the parameters that affect the airflow, and consequently the airborne particle trajectories within the room is desirable. Computational Fluid Dynamics (CFD) is an alternative to tedious and time-consuming experimental investigations during the design phase, when a large number of alternatives need to be evaluated. The main limitations of CFD application in building design are the high level of skill required, the complexity of the setup phase, and the difficulty of output data interpretation using common 2D (two-dimensional) display devices. A virtual reality (VR) environment can help in overcoming some of these limitations. A CFD/VR procedure for design of contaminant-free hospital facilities is presented in this paper. By means of a VR preprocessing step, inferior solutions can be discharged to drastically reduce the number of configurations to investigate. Then, a CFD/VR tool is used to explore the restricted set of room layouts. The 3D (three-dimensional), immersive visualisation of an indoor space and of the particle motion inside it allows the user to really see the particle flows and consequently understand the effects of room parameters on particle motion throughout the room. In this way a close-to-optimal configuration of the room layout and of the ventilation system can be achieved more speedily and more conveniently compared to traditional CFD investigations.     

Effects of display technologies on operation performances and visual fatigue

The use of 3D stereoscopic display technology in all aspects of life has attracted considerable research attention. However, only few studies have simultaneously considered the effects of stereoscopic display technologies on visual fatigue and operating performances. This study with 36 participants (50% females; mean age = 23.17 years, SD = 3.3) analyzed the effects of display technologies, task complexity, and use time on operation performances, subjective and objective visual fatigue. Results indicated that display technology did not significantly affect the operation performances, whereas task complexity did. However, no interaction took place between them. Display technology had no significant effects on subjective visual fatigue and near-point accommodation (NPA) but affected critical fusion frequency (CFF) significantly. Use time had significant effects on both subjective and objective visual fatigue.     

A study of cybersickness and sensory conflict theory using a motion-coupled virtual reality system

Sensory conflict theory explains that motion sickness in virtual reality (VR) systems can be caused due to the mismatch between visual and vestibular senses. This study examines whether coupling physical motions to visual stimuli in VR could reduce this discomfort. A motion-coupled VR system developed on a motion platform, providing vestibular cues to supplement visual roll from a head-mounted display (HMD), was used. Three conditions were tested: visual rotation only (stationary), visual-physical motion synchronised (synchronous), and vestibular motion with a self-referenced visual environment. Results show that when users are placed under a visual-vestibular synchronised condition, their subjective miserable score of cybersickness decreased while their comfort level of the overall experience increased. This indicates that a motion-coupled system, if integrated seamlessly in VR, could mitigate cybersickness symptoms.     

Effects of virtual presence and learning outcome using low-end virtual reality systems

Low-cost technology is essential to integrate Virtual Reality (VR) into educative institutions around the world. However, low-cost technology usually refers to low-end technology, which may compromise the level of immersion of the VR system. This study evaluates whether low-end and high-end VR systems achieve a comparable learning outcome regardless their immersion level. We also analyze the relationship between virtual presence and the learning outcome arising from a VR educational experience. An evaluation with 42 participants was conducted. We measured learning outcome and virtual presence under three different configurations, namely: a desktop computer, a low-end VR system, and a high-end VR system. The impact of simulator sickness was also analyzed. Results revealed a lower learning outcome in the less immersive configuration (i.e. desktop) and a similar learning outcome in both low-end and high-end VR systems. Even though low-end VR systems are less immersive and produce a lower level of virtual presence than high-end VR systems, the results support the use of low-end VR systems for educative applications.     

基于虚拟技术的MACS实训室的构建

针对过程控制专业实验实训及工厂培训设备M A C S控制系统价格特别昂贵,培训效果差的状况,提出建立基于虚拟技术的MACS实训室的构想。虚拟MACS实训室采用虚拟仪器技术、虚拟现实技术、计算机网络技术、多媒体技术,将昂贵的工业控制系统扩展到网络化的多媒体教学中,实现了由多人共用一套实训设备到每人单独使用此套实训设备的转变,充分利用了硬件资源,极大地节省了实训设备的投资,提高了教学质量与教学效果。