数字维修平台中可视化交互系统的研究与实现

在导航装备数字维修平台中,提出了一种新的面向Agent思想的可视化交互系统的结构模型,该模型采用B／S模式网络平台构建;将网络化虚拟现实技术应用于装备维修领域,针对某型惯性导航装备,给出了基于Cult 3D虚拟现实技术的可视化交互系统的实现方法,虚拟装备的动作由用户自定义的Java类灵活控制。该交互系统与B／S网络平台可实现无缝结合,处于网络中的用户只需通过浏览器即可与虚拟装备进行交互。系统测试表明,该设计方案完全可行,虚拟导航装备形象逼真。交互性好,可便于维修人员深入了解装备的内部结构,从而提高工作效率。     

Identification of metaphors for virtual environment training systems

The objective of this effort was to develop potential metaphors for assisting wayfinding and navigation in current virtual environment (VE) training systems. Although VE purports a number of advantages over traditional, full-scale simulator training devices (deployability, footprint, cost, maintainability, scalability, networking), little design guidance exists beyond individual instantiations with specific platforms. A review of metaphors commonly incorporated into human-computer interactive systems indicated that existing metaphors have largely been used as orientation aids, mainly in the form of guided navigational assistance, with some position guidance. Advanced metaphor design concepts were identified that would not only provide trainees with a useful orienting framework but also enhance visual access and help differentiate an environment. The effectiveness of these concepts to aid navigation and wayfinding in VEs must be empirically validated.     

Identification of metaphors for virtual environment training systems

The objective of this effort was to develop potential metaphors for assisting wayfinding and navigation in current virtual environment (VE) training systems. Although VE purports a number of advantages over traditional, full-scale simulator training devices (deployability, footprint, cost, maintainability, scalability, networking), little design guidance exists beyond individual instantiations with specific platforms. A review of metaphors commonly incorporated into human—computer interactive systems indicated that existing metaphors have largely been used as orientation aids, mainly in the form of guided navigational assistance, with some position guidance. Advanced metaphor design concepts were identified that would not only provide trainees with a useful orienting framework but also enhance visual access and help differentiate an environment. The effectiveness of these concepts to aid navigation and wayfinding in VEs must be empirically validated.     

基于三维仿真的输（调）水系统实时调控实现平台研究

以南水北调中线工程为例,研制基于三维仿真的输(调)水系统的实时调控实现平台。研究虚拟仿真平台的构建、海量数据的分页调度、碰撞检测、闸门建模等技术,实现场景三维可视化与漫游、二维导航图与三维场景的实时联动、基于三维场景的集成查询与显示、基于水量调度模型的调水方案的分层显示、基于水动力学模型的三维水面动态模拟和流场动态可视化、基于实时调控的闸门可视化动态仿真等功能。该平台可为南水北调中线工程运行管理决策支持系统建设提供技术支撑,并为相似工程提供借鉴。     

基于CPS架构的旋翼无人机组合定位建模研究

针对在特殊地区连续导航和组合导航冗余技术的问题,提出基于信息物理融合系统架构的BDS/GPS/SINS组合导航的旋翼无人机定位方案。以六旋翼为运载体,采用超紧组合导航结构和联邦式滤波结构建立模型,通过Simulink虚拟定位仿真,得到较为精确的位置信息。进一步搭建旋翼无人机物理融合定位系统实验平台,该平台的BDS/GPS接收机接收由NSS8000多星群模拟器提供的虚拟卫星导航电文信号,方便用户对CPS虚拟和现实环境的人机交互界面进行操作。通过定位信息融合进行基于BDS/GPS/SINS超紧组合导航的室内飞行实验,失星下定位精度都能达到2.0?m±0.5?m。仿真和实验结果表明,该定位系统具有信息物理融合的鲁棒性和安全可靠性。     

Exploration of architectural spaces by blind people using auditory virtual reality for the construction of spatial knowledge

Navigation within a closed environment requires analysis of a variety of acoustic cues, a task that is well developed in many visually impaired individuals, and for which sighted individuals rely almost entirely on visual information. For blind people, the act of creating cognitive maps for spaces, such as home or office buildings, can be a long process, for which the individual may repeat various paths numerous times. While this action is typically performed by the individual on-site, it is of some interest to investigate at which point this task can be performed off-site, at the individual's discretion. In short, is it possible for an individual to learn an architectural environment without being physically present? If so, such a system could prove beneficial for navigation preparation in new and unknown environments. The main goal of the present research can therefore be summarized as investigating the possibilities of assisting blind individuals in learning a spatial environment configuration through the listening of audio events and their interactions with these events within a virtual reality experience. A comparison of two types of learning through auditory exploration has been performed: in situ real displacement and active navigation in a virtual architecture. The virtual navigation rendered only acoustic information. Results for two groups of five participants showed that interactive exploration of virtual acoustic room simulations can provide sufficient information for the construction of coherent spatial mental maps, although some variations were found between the two environments tested in the experiments. Furthermore, the mental representation of the virtually navigated environments preserved topological and metric properties, as was found through actual navigation.     

基于虚拟导航线的农业机器人精确视觉导航方法

针对农田、野外环境中无人工标记情况下的导航问题,提出了一种基于虚拟导航线的农业机器人精确视觉导航方法。该方法不需要铺设导航线或者路标即可引导机器人行走直线。首先,根据需求确定需要跟踪的目标区域,之后控制机器人调整方向直到目标移至视野中央;其次,根据机器人和目标的位置确定参照目标,并依据两个目标的位置确定虚拟导航线;然后,动态更新导航线,并结合虚拟定标线和虚拟导航线确定偏移角度和偏移距离;最后,利用偏移参数构建模糊控制表,并以此实现对机器人旋转角度和行走速度的调整。实验结果表明,该算法能较为精确地实现对导航路线的识别,进而利用模糊控制策略使机器人沿直线向目标行走,且导航精度在10 cm以内。     

虚拟环境中虚拟化身的设计与实现

虚拟人是虚拟现实中一个重要的组成部分。虚拟人正在越来越多的被应用于不同的领域,比如军事领域、生物工程、模拟急救紧急事件和虚拟导游。虚拟人的建模需要考虑不同抽象层次上的问题。为了增加在虚拟旅游中的导航帮助和用户在虚拟环境中的沉浸感,在虚拟环境中设置虚拟导游是一种理想的选择。本文主要对目前构建虚拟人过程中用到的主要方法进行分析总结,并提出构建具有虚拟导游行为特点的虚拟人的想法。     

Intelligent Cruise-Control Navigation: A new navigation/travel method for use in virtual environments

An important feature of virtual reality is the facility for the user to move around a virtual environment in a natural and easily controlled manner. Navigation, also called locomotion, travel or motion, involves changing the perspective of the user in the virtual environment (VE). It allows the user to move in the VE as well as reorient themselves to look at the world differently. Natural locomotion methods are able to contribute to a sense of presence and reality. The illusion of presence can be lost through unnatural experiences during travel in the VE. This can be caused by poor interactive metaphors or by experiences which do not agree with the user's everyday understanding of the real world. This paper focuses on the navigation method in the VE, one of the major interfaces for the interactivity between human and VE in virtual reality circumstances and worlds. It proposes a new navigation method. Intelligent Cruise-Control Navigation (ICCN), which provides a natural and user-centred approach to navigation in the VE and can improve the user's sense of reality and presence. ICCN is composed of three major phases: Constant Velocity Navigation, Collision Detection and Avoidance, and Path Adjustment. The ICCN can reduce the user's fatigue and improve the user's presence in the VE. The small experimental study reported in this paper suggests that the ICCN will be a natural, straightforward, and useful navigation interface in VE.     

Going to town: Visualized perspectives and navigation through virtual environments

Two experiments examined how spatial learning perspectives support navigation through virtual urban environments. Participants briefly learned the overall layout of a virtual desktop environment, and then were taken on a simulated journey ending at a starting location within the environment. In Experiment 1, during the journey participants watched simulated video feeds either from the front of the vehicle (route perspective), above the vehicle (survey perspective), both feeds simultaneously, or no video at all. Participants then navigated between ten successive landmarks, and we measured indices of spatial and temporal efficiency, and heading error. Results indicated that the route perspective supported a restricted range of local navigation whereas the survey perspective better supported far-space navigation. Experiment 2 demonstrated that the survey perspective also better supports navigation around unexpected detours. Results are discussed with regard to theories of spatial memory and the design of computer-supported spatial visualization technologies.     

Manipulating subjective realism and its impact on presence: Preliminary results on feasibility and neuroanatomical correlates

The feeling of presence has been shown to be an important concept in several clinical applications of virtual reality. Among the factors influencing presence, realism factors have been examined extensively from the angle of objective realism. Objective realism has been manipulated by altering numerous technological characteristics such as pictorial quality, texture and shading, or by adding more sensory information (i.e., smell, touch). Much less studied is the subjective (or perceived) realism, the focus of the two pilot studies reported in this article. In Study 1, subjective realism was manipulated in order to assess the impact on the feeling of presence. Method: Presence was measured in 31 adults after two immersions in virtual reality. Participants were immersed in a neutral/irrelevant virtual environment and subsequently subjected to the experimental manipulation. Participants in the experimental condition were falsely led to believe that they were immersed live in real time in a “real” room with a “real” mouse in a cage. In the control condition, participants believed they were immersed in a replica of the nearby room. All participants were actually immersed in the exact same virtual environment. Results: A manipulation check revealed that 80% of the participants believed in the deception. A 2 Times by 2 Conditions repeated measure ANOVA revealed that leading people to believe they were seeing a real environment digitized live in virtual reality increased their feeling of presence compared to the control condition. In Study 2, the same experimental design was used but with simultaneous functional magnetic resonance imaging (fMRI) in order to assess brain areas potentially related to the feeling of presence. fMRI data from five participants were subjected to a within subject fixed effect analysis to verify differences between the experimental immersion (higher presence) and the control immersion (lower presence). Results revealed a statistically significant difference in left and right parahippocampus areas. Conclusion: Results are discussed according to layers of presence and consciousness and the meaning given to experiences occurring in virtual reality. Some suggestions are formulated to target core presence and extended presence.     

基于Virtools的《机械设计》课程虚拟仿真学习平台的研究

传统的《机械设计》课程教学依赖于平面图纸和简单模型,整体教学效果不够理想.基于Virtools的《机械设计》课程虚拟仿真学习平台利用Pro/E创建模型导入Virtools中进行交互设计,从而构建了机械零部件的虚拟装配环境,将虚拟仿真技术和机械设计教学结合起来具有高度的沉浸感和良好的交互性,从而加速和巩固学生学习知识的过程.     

A collaborative Design for Usability approach supported by Virtual Reality and a Multi-Agent System embedded in a PLM environment

This paper details a collaborative workstation design approach integrating knowledge based on engineering process, using a Multi-Agent System (MAS) on a Virtual Reality (VR) platform. The MAS supports R&D teams to extract and re-use engineering knowledge so as to improve their efficiency in developing new products. Our research targets the development of a knowledge engineering system integrated into a PLM-Product Life cycle Management-environment linked with virtual reality tools. A PLM is a strategic business approach with a consistent set of methodologies and software solutions. It is meant to promote collaborative creation, management, delivery and proper use of this life cycle definition and information product in multinational companies. This system is used by engineers to carry out projects in a collective way while conveying a defined process. The MAS allows capitalization, and to annotate knowledge according to the actions of the designers inside a PLM environment. Then, this knowledge is used by VR tools to analyze various aspects of the virtual prototype such as manufacturing, maintenance, reliability or ergonomics. Consequently, we use expert knowledge to pilot the design process of a virtual prototype inside a three-dimensional immersive virtual reality platform. In this context, our paper describes our knowledge management approach applied to improve ergonomics and collaborative design in industrial areas.     

A New Mobile Robot Toolbox for Matlab

In this study, a wheeled mobile robot navigation toolbox for Matlab is presented. The toolbox includes algorithms for 3D map design, static and dynamic path planning, point stabilization, localization, gap detection and collision avoidance. One can use the toolbox as a test platform for developing custom mobile robot navigation algorithms. The toolbox allows users to insert/remove obstacles to/from the robot’s workspace, upload/save a customized map and configure simulation parameters such as robot size, virtual sensor position, Kalman filter parameters for localization, speed controller and collision avoidance settings. It is possible to simulate data from a virtual laser imaging detection and ranging (LIDAR) sensor providing a map of the mobile robot’s immediate surroundings. Differential drive forward kinematic equations and extended Kalman filter (EKF) based localization scheme is used to determine where the robot will be located at each simulation step. The LIDAR data and the navigation process are visualized on the developed virtual reality interface. During the navigation of the robot, gap detection, dynamic path planning, collision avoidance and point stabilization procedures are implemented. Simulation results prove the efficacy of the algorithms implemented in the toolbox.     

Large displays enhance optical flow cues and narrow the gender gap in 3-D virtual navigation

OBJECTIVE: Existing reports suggest that males significantly outperform females in navigating 3-D virtual environments. Although researchers have recognized that this may be attributable to males and females possessing different spatial abilities, most work has attempted to reduce the gender gap by providing more training for females. In this paper, we explore using large displays to narrow the gender gap within these tasks. BACKGROUND: While evaluating various interaction techniques, we found that large displays affording wider fields of view seemed to improve virtual navigation performance in general and, additionally, to narrow the gender gap that existed on standard desktop displays. METHOD: We conducted two experiments (32 and 22 participants) exploring the individual contributions of display and geometric fields of view to the observed effects as well as isolating factors explaining performance increases seen on the large displays. RESULTS: We show that wider fields of view on large displays not only increase performance of all users on average but also benefit females to such a degree as to allow them to perform as well as males do. We further demonstrate that these benefits can be attributed to better optical flow cues offered by the large displays. CONCLUSION: These findings provide a significant contribution, including recommendations for the improved presentation of 3-D environments, backed by empirical data demonstrating performance benefits during navigation tasks. APPLICATION. Results can be used to design systems that narrow the gender gap in domains such as teleoperation and virtual environments for entertainment, virtual training, or information visualization.     

Situation awareness and driving performance in a simulated navigation task

The objective of this study was to identify task and vehicle factors that may affect driver situation awareness (SA) and its relationship to performance, particularly in strategic (navigation) tasks. An experiment was conducted to assess the effects of in-vehicle navigation aids and reliability on driver SA and performance in a simulated navigation task. A total of 20 participants drove a virtual car and navigated a large virtual suburb. They were required to follow traffic signs and navigation directions from either a human aid via a mobile phone or an automated aid presented on a laptop. The navigation aids operated under three different levels of information reliability (100%, 80% and 60%). A control condition was used in which each aid presented a telemarketing survey and participants navigated using a map. Results revealed perfect navigation information generally improved driver SA and performance compared to unreliable navigation information and the control condition (task-irrelevant information). In-vehicle automation appears to mediate the relationship of driver SA to performance in terms of operational and strategic (navigation) behaviours. The findings of this work support consideration of driver SA in the design of future vehicle automation for navigation tasks.     

Immersive Whiteboard Collaborative System

An immersive whiteboard system is presented where users at multiple locations can communicate with each other. The system features a virtual environment with vivid avatars, stroke compression and streaming technology to effectively deliver stroke data across meeting participants, friendly human interaction and navigation, virtual and physical whiteboard. The whiteboard is both a physical platform for our input/output interfaces and a virtual screen for sharing common multimedia. It is this whiteboard correspondence that allows the user to physically write on the virtual whiteboard. In addition to drawing on the shared virtual board, the immersive whiteboard in our setup permits users to control the application menus, insert multimedia objects into the world, and navigate around the virtual environment. By integrating multimedia objects and avatar representations into an immersive environment, we provide the users with a more transparent medium so that they feel as if they are communicating and interacting face-to-face. The whiteboard efficiently pulls all the collaboration technologies together. The goal of this collaborative system is to provide a convenient environment for participants to interact with each other and support collaborative applications such as instant messaging, distance learning and conferencing.     

Teaching training in a mixed-reality integrated learning environment

In this mixed-method study, we examined the design and potential impact of a mixed-reality integrated learning environment (MILE) in providing the simulated and immersive teaching practice for university teaching assistants. A virtual-reality-based learning platform integrating a Kinect-enabled sensorimotor interface was developed and used by twenty three university teaching assistants. Qualitative and quantitative data on the participants' participation behaviors, engagement, and perceptions were collected via video/screen recording, interview, surveys on teaching self-efficacy and sense of presence, and eye tracking. Results indicated that the MILE reinforced sense of presence and supported the performance of an ample range of virtual teaching tasks/actions with avatar-embodied live gesturing. The environmental fidelity in the mixed-reality learning spaces, the design and arrangement of virtual agents and avatars, and the affordance of embodied gesturing and walking are salient MILE design features that affected participants' sense of presence and their virtual teaching performance.