The reality of virtual environments

In this article, the reality of virtual environment is described in detail. Highly detailed three-dimensional (3D) computer models and environments are commonly used in design, manufacturing, simulation, and entertainment. These virtual environments (VEs) are often successful at appearing realistic when time remains still, but as the mobile objects are set into motion and interact with their surroundings, the movements often appear unnatural. In many prerendered VEs used for entertainment purposes, all of the object's motions must be handmade by 3-D animators in a process that is time consuming and lacks strict realism. In other VEs such as the first generation of 3-D video games, objects are modeled by their bounding space or by a sphere that surrounds all of the 3-D model's vertices. In these cases, the motions are often quite linear, and the collision response algorithms are quite simplistic; some even revert to stopping an object's motion when it collides with the environment. These techniques are much too minimal and greatly reduce the level of realism in VEs.     

Applying virtual reality

Virtual reality (VR) immerses a user within a simulated three-dimensional environment. Still in its infancy, much remains to be done, but the field shows great promise. Computer processing speed, graphics, networks, and specialized peripherals all play a part in creating believable applications. In a full VR implementation, the user wears specialized goggles that substitute small video displays for the lenses, one for each eye. The displays become the “lenses” onto a simulated world. The head-mounted display containing the goggles detects head movement and updates the user's view accordingly; the user has the impression of looking around, even moving within, the simulated environment. The sensory experience can be further enriched with sound, or a data glove to simulate contact between the user and simulated objects. In a partial VR implementation, a computer's video display becomes a window onto the simulated environment, and no external gear is required. In a networked environment, people can be immersed in the same simulation, each perceiving it from their own point of view     

A virtual reality testbed for brain-computer interface research.

Virtual reality promises to extend the realm of possible brain-computer interface (BCI) prototypes. Most of the work using electroencephalograph (EEG) signals in VR has focussed on brain-body actuated control, where biological signals from the body as well as the brain are used. We show that when subjects are allowed to move and act normally in an immersive virtual environment, cognitive evoked potential signals can still be obtained and used reliably. A single trial accuracy average of 85% for recognizing the differences between evoked potentials at red and yellow stop lights will be presented and future directions discussed.     

基于虚拟现实技术的电子虚拟实验室的构建

应用虚拟现实技术构建的电子虚拟实验室与传统的电子实验室相比,有着巨大的优越性.本文就虚拟现实技术在构建虚拟电子实验室方面的应用进行说明,介绍了虚拟电子实验室构成的硬件和软件平台,及具体的构建方法,主要侧重于介绍电子虚拟仪器的构建以及虚拟电子实验室的构建.文中结合作者自己研究实现的成果,分别以虚拟的低频信号发生器和虚拟的电路实验为代表,以实际的例子加以说明电子虚拟实验室在构建过程中的关键技术.     

An integrated virtual learning system for the development of motordrive systems

This paper describes the basic concept of an integrated virtual learning system as an instructional tool for the development of digital signal processor (DSP)-based control schemes for motor drive applications. The system is comprised of a graphical user interface (GUI) front-end and a hardware-in-the-loop custom DSP for rapid prototyping and efficient testing of digital control algorithms. The circuit design and control algorithm development of a pulse width modulation (PWM) voltage source inverter (VSI) for 3-phase brushless DC (BLDC) motor control applications is used to describe the functions of the system. It is shown that the virtual learning system provides a cost-effective learning tool for students or engineers in training and can serve as a supplement to a conventional laboratory based system     

Substation simulation system using virtual reality technology

An indoor distribution substation simulation system based on virtual reality technology has been developed. The system is designed to give the user the feeling of actually touring a substation for routine inspection. Various states of the substation facilities, such as the opening and closing of the doors and the disconnectors as well as the relocation and extension of the installations, can be simulated. In the event the user approaches the energized components of the equipment and fails to keep the specified insulation distance from them, the system first sounds an alarm, and then a flashing red light on the display warns of passage beyond the safety point and that the operation has suffered an electric shock. Validation of equipment operating procedures, training of unskilled workers and work-schedule preparation can be upgraded by using this system.     

Evolution of virtual reality [Medicine]

Although original applications in virtual reality (VR) for medicine pertained to the planning of surgeries, efforts have now shifted to the use of data fusion, i.e. to fuse virtual patients onto real patients as a navigational aid in surgery. Eventually, medical care with multiple professionals will be provided in a shared virtual environment that incorporates shared decision making for an actual surgical intervention or a rehearsal. The major applications of virtual reality in surgery can be divided into three areas: virtual humans for training, the fusion of virtual humans with real humans for performing surgery, and virtual telemedicine shared decision environments for training of multiple players. The applications pertaining to the realisation of virtual reality in medicine can be categorised into two areas: generic models and patient specific models     

Augmented reality and virtual reality displays:emerging technologies and future perspectives

With rapid advances in high-speed communication and computation, augmented reality (AR) and virtual reality (VR) are emerging as next-generation display platfor...     

A virtual reality environment for designing and fitting neural prosthetic limbs.

Building and testing novel prosthetic limbs and control algorithms for functional electrical stimulation (FES) is expensive and risky. Here, we describe a virtual reality environment (VRE) to facilitate and accelerate the development of novel systems. In the VRE, subjects/patients can operate a simulated limb to interact with virtual objects. Realistic models of all relevant musculoskeletal and mechatronic components allow the development of entire prosthetic systems in VR before introducing them to the patient. The system is used both by engineers as a development tool and by clinicians to fit prosthetic devices to patients.     

流域三维虚拟仿真平台研究

流域三维仿真是流域数字化的重要组成部分,要开发基于流域的虚拟仿真平台,需要妥善解决海量信息的存储共享与多种功能模块间的集成问题。本文将平台集成开发划分为三维可视化、数学模型计算和数据库三个功能模块。以都江堰为例,讨论了平台开发的总体框架和系统数据库,重点探讨了三维可视化与数学模型计算及数据库之间信息集成和交互的关键技术。     

Augmented reality systems for medical applications

Augmented reality (AR) is a technology in which a computer-generated image is superimposed onto the user's vision of the real world, giving the user additional information generated from the computer model. This technology is different from virtual reality, in which the user is immersed in a virtual world generated by the computer. Rather, the AR system brings the computer into the “world” of the user by augmenting the real environment with virtual objects. Using an AR system, the user's view of the real world is enhanced. This enhancement may be in the form of labels, 3D rendered models, or shaded modifications. In this article, the authors review some of the research involving AR systems, basic system configurations, image-registration approaches, and technical problems involved with AR technology. They also touch upon the requirements for an interventive AR system, which can help guide surgeons in executing a surgical plan     

地下变电站虚拟现实仿真系统的研究

地下变电站全部采用室内封闭式组合电气设备(GIS),其电站环境也是封闭式的,因此需要大量工业辅助设备保证其安全运行,与常规变电站相比对运行人员提出了更高的要求.利用三维造型软件和虚拟开发平台对复杂的地下变电站运行环境进行虚拟再现,针对地下变电站的特点对学员进行地下变电站日常巡视、操作和事故处理等仿真培训.经测试,该培训系统扩展性好、真实感强,可模拟变电站的扩建和改造,在虚拟变电站中进行变电设备的在线编辑,满足地下变电站长期规划下的仿真培训需要.     

基于虚拟现实的城市溃堤洪水淹没过程仿真

溃堤洪水淹没过程研究对防洪减灾具有重要的现实意义.以哈尔滨市主城区为例,讨论了基于虚拟现实技术建立城市防洪综合信息平台的总体结构,重点研究了城市防洪中溃堤洪水的淹没过程仿真.采用水动力学模型计算法和水深比较法两种方法研究了哈尔滨城区溃堤洪水淹没过程,比较了两种方法的优缺点.将水动力学模型计算结果与连通域搜索方法相结合,实现了三维虚拟环境中洪水演进过程的平滑模拟仿真.     

微型虚拟现实头部跟踪系统的设计

头部跟踪系统是虚拟现实系统中的关键部分之一,它的任务是检测头部的姿态与方位。设计一种基于两轴磁阻效应传感器和三轴MEMS加速度传感器的微型虚拟现实头部跟踪系统,首先阐述了系统的基本原理及整体构成,其次给出了硬件设计以及头部方位、姿态求解的算法;最后,给出了系统的运行效果。结果表明,该头部跟踪系统可实际应用于头部缓慢转动场合,同时具有体积小、功耗低、性价比高的优点。     

A new rehabilitation training system for postural balance control using virtual reality technology.

A new rehabilitation training system, designated as a virtual cycling system, was developed to improve postural balance control by combining virtual reality (VR) technology with a bicycle. Several parameters including path deviation, path deviation velocity, cycling time, and head movement were extracted and evaluated to quantify the extent of control. The system was effective as a training device and, in addition, the technology might have a wider applicability to the rehabilitation field.     

基于虚拟现实环境的脑机接口技术研究进展

将脑-机接口(brain-computer interface,BCI)技术与虚拟现实(virtual reality,VR)相结合构成基于虚拟现实的脑-机接口(BCI-VR)新技术是最近在多媒体和娱乐领域出现的一种BCI应用新模式。BCI-VR兼取两者优势互补,同时又相互促进创新,显示出广阔应用前景。本文从BCI-VR系统基本构成、BCI对VR控制和VR对BCI影响等方面,较详细介绍了近年来BCI-VR的主要研究方法、研究进展和成就,并根据作者体会小结了目前存在的难点与未来的可能发展动向,以与读者交流、共同促进BCI-VR新技术的快速发展。     

Guidelines for establishing a virtual reality lab [medicalapplications]

Gives guidelines for establishing a virtual reality (VR) laboratory in the context of medical applications. In order to set up the laboratory, a user analysis and a task analysis must first be performed. A VR system's components have to be carefully selected, depending on their functionality and their use within the medical environment. The advantages of the individual components are not the only criteria for their choice; their interrelation with the system also has to be taken into account. In addition, cost is often an important limiting factor in establishing a laboratory     

An integrated system for assessing stroke risk.

The objective of this article is to present an integrated system for the assessment of risk of stroke based on two modules: 1) clinical risk factors and noninvasive investigations, and 2) carotid plaque texture analysis. The system supports the data collected from the Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) natural history study that includes following data: 1) clinical, biochemical, and electrocardiographic risk factors associated with cardiovascular deaths, and 2) whether any independent risk factors can be used to identify a high-risk group for cardiovascular death. Furthermore, the carotid plaque texture analysis module supports the normalization, despeckling, segmentation, texture feature extraction, and classification of ultrasound plaque images.     

增强虚拟现实技术在播音主持专业实践教学中的应用研究

为了解决播音主持专业的实践教学存在教学目标与媒体需求相脱节,教学资源投入有限和现代化的多媒体设备昂贵的矛盾,实践大纲内容简单和对主持人素质要求随着技术发展越来越高的瓶颈等问题,通过报道事故类型的新闻,将增强现实技术进行实践运用,通过虚拟场景重建技术、三维建模、模型渲染等技术手段为发生的事故案例进行场景恢复,然后将主持人嵌入到发生过被重构的三维场景中,增强这类报道的临场感和真实性,提高节目的吸引力和对主持专业学生可以积累临场发挥经验起到积极作用.