对基于虚拟现实训练系统的低成本3D声音系统评估

在基于PC的虚拟训练系统中,3D的声音仿真能够大幅度的提高VR系统的能力.然而,现实的3D仿真非常昂贵,而且计算混响,阻塞和延时效果需要配置具有强大运算能力的系统.因此,必须提供一个低成本的方案,使其能在更广的范围内得到应用.对一个低成本3D声音仿真系统的评测进行了重点阐述.实验设置基于常规的立体声耳机和一个可跟踪的头戴式设备,实验中使用不同信号在虚拟训练环境中来定位声音,最后从精度和速度来表述实验结果.     

舰船训练虚拟系统的设计研究

在建立虚拟舰船仿真系统的研究中,由于舰船的船舱仪表数量多,船体操控复杂,目前还没有舰船虚拟训练系统。针对舰船训练实际需求,提出一种虚拟仪表和游戏引擎相结合的舰船虚拟训练系统设计思想。借助于Ogre、ODE及数据手套、数据头盔和定位器等虚拟现实设备,建立仿真数据模型,解决了场景中的虚拟手交互、碰撞检测等关键技术问题,完成虚拟手对舰船的实时控制。实验结果表明,仿真系统在保证真实性和快速性的同时,还易于操控等特点,能使用户快速掌握舰船驾驶和仪表操作的基本方法,训练周期缩短60%,大大降低了训练成本。     

虚拟情景实训环境三维模拟

应用计算机技术当中的虚拟模拟技术,对于当前各领域实现虚拟情景三维模拟训练已成为可能。本文研究当前技术环境下,利用Unity3D模拟平台构造虚拟情景训练系统的开发与设计。从三维模拟训练系统的关键技术研究入手,以三维场景优化、物理碰撞逻辑检测、动态加载场景以及网络通信作为开发的重点,设计出较为先进和逼真的虚拟情境下三维模拟训练系统。并以消防部门作为系统应用的检测部门,检测结果表示此系统可以很好的表现出现场场景的模拟程度以及逻辑,对于加强消防部门的训练技术和应用效果有很大优势。     

基于Quest3D的钻床加工虚拟教学系统的研究

针对培训系统要求人机交互界面好以及沉浸感强等特点,在钻床教学系统开发中采用实时3D建构工具Quest3D,提出了一种针对钻床教学培训的虚拟现实系统的开发方案,将虚拟现实系统分为三维显示模块,运动控制模块,场景交互模块和场景声控模块等,通过Quest3D的图形编程使得整个系统开发周期缩短,运行效率提高。成功将三维场景虚拟交互技术运用于钻床教学培训系统中。     

基于虚拟现实仿真飞行模拟训练研究

现行众多仿真设备费用昂贵,且体积庞大。为降低成本,在沉浸性虚拟仿真座舱中进行飞行训练,受训者可通过HMD和数据手套与系统交互进行模拟训练,确保首次实机飞行前积累丰富驾驶经验。针对美军现行的基于虚拟现实训练系统中的座舱仿真技术进行研究并讨论,并给出其主要特点。     

Light-field head-mounted displays reduce the visual effort: A user study

Head-mounted displays (HMDs) allow the visualization of virtual content and the change of view perspectives in a virtual reality (VR). Besides entertainment purposes, such displays also find application in augmented reality, VR training, or tele-robotic systems. The quality of visual feedback plays a key role for the interaction performance in such setups. In the last years, high-end computers and displays led to the reduction of simulator sickness regarding nausea symptoms, while new visualization technologies are required to further reduce oculomotor and disorientation symptoms. The so-called vergence–accommodation conflict (VAC) in standard stereoscopic displays prevents intense use of 3D displays, so far. The VAC describes the visual mismatch between the projected stereoscopic 3D image and the optical distance to the HMD screen. This conflict can be solved by using displays with correct focal distance. The light-field HMD of this study provides a close-to-continuous depth and high image resolution enabling a highly natural visualization. This paper presents the first user-study on the visual comfort of light-field displays with a close-to-market HMD based on complex interaction tasks. The results provide first evidence that the light-field technology brings clear benefits to the user in terms of physical use comfort, workload, and depth matching performance.     

悬臂式掘进机虚拟仿真平台设计

悬臂式掘进机广泛应用于煤矿井下巷道施工,掘进机的培训包括传统的书本教学方法和基于井下实际操作的训练方法,但是由于其场地和安全的局限性,无法满足训练要求.针对这一现状,利用虚拟现实技术和交互仿真技术构建了悬臂式掘进机虚拟仿真平台.该平台采用三维建模技术,使用多边形建模方法制作了悬臂式掘进机、转载机、供电系统等三维模型;运用Unity3D引擎驱动三维模型组成的虚拟场景,采用场景优化技术实时渲染出沉浸式的虚拟场景;在脚本语言C#编程环境下实现操作流程顺序控制、操作描述、三维模型驱动等,实现悬臂式掘进机虚拟仿真培训.培训结果表明,沉浸式人机交互可达到与实物培训相类似的效果,提高使用者学习和操作悬臂式掘进机的效率.     

Research on hybrid synchronization methods in multi-user collaborative VR simulation medical surgery training system

The simulation training system based on VR technology has been applied in clinical medicine due to its immersive interactive experience, economy, and safety. In response to the limitation that most medical surgery training systems can only achieve single user operations, a hybrid synchronous model based multi-user collaborative framework design is proposed to meet the needs of collaborative training in virtual reality teaching processes. Based on the characteristics of frame synchronization and state synchronization, the synchronization method has been improved. Based on frame synchronization, specific state synchronization is used on interactive events to improve the consistency of operation details and real-time action. On this basis, a system prototype has been implemented using Unity 3D, and compared with traditional schemes, analysis shows that it has faster response speed for disconnected reconnection and more stable interaction state.     

带电作业绝缘斗臂车虚拟仿真系统的设计与开发

将带电作业中的绝缘斗臂车操作训练与虚拟现实技术相结合,以Quest3D4.0和VC++ 6.0等软件为开发平台,在完成整体设计的基础上实现了绝缘斗臂车虚拟仿真系统。系统通过建立视景仿真和绝缘斗臂车模拟控制系统,受训者可在虚拟操作环境中真实体验在现实世界中的工况,有力地保障了仿真培训的效果,为电力系统的带电作业培训提供了一种新的思维方式。     

基于主变起火应急演练的虚拟现实培训系统

为提高火灾应急演练的训练能力,提出基于主变起火应急演练的虚拟现实培训方法。在3D虚拟现实视景模型下计算起火环境的单尺度特征参数,并根据参数结果构建图像输出模型,结合主变起火应急演练模糊控制方法进行虚拟现实培训的三维重构,实现主变起火应急演练虚拟现实培训的控制,在虚拟现实系统中进行主变起火应急演练的视景重构,在视点位置中进行主变起火应急演练的3D虚拟现实模拟,实现基于主变起火应急演练的虚拟现实培训设计。仿真结果表明,采用该方法进行虚拟现实培训系统设计的帧渲染速度快、特征配准率高。     

虚拟仿真在海洋平台钻修井作业培训中的应用

针对目前海洋平台钻修井作业培训模拟仿真系统中环境代入感差、操作沉浸感差的不足,建立一套基于Unity-3D平台的具有交互功能、临界真实操作环境的钻柱自动化处理虚拟仿真系统。采用海上钻修井平台的实际数据对该系统进行仿真应用,结果表明,本系统可以为训练人员营造逼真的训练环境,通过在本虚拟仿真系统中的训练可以提高操作人员的操作技能和对特殊情况的处置能力。     

Teaching your system to share

Creating multi-user virtual worlds is a relatively new challenge for developers of virtual reality applications. It is especially challenging to build networked VR systems based on inexpensive PC-based hardware, due to limitations in system software and inefficient networking hardware. This article explains how we created a multi-person shared virtual environment using DOS-based PCs. It also covers some of the design goals in creating a collaborative design tool for creating and modifying virtual buildings. Workroom is a general purpose simulation infrastructure that allows multiple participants to interact in unpredictable ways while minimizing simulation latency     

某型吊舱训练模拟器的建模与仿真

介绍构建某型吊舱训练模拟器的建模和仿真方法,重点研究系统实现三维建模和交互式控制技术等关键问题的解决方案,对研发其他装备的虚拟仿真训练系统具有一定的借鉴意义。     

某型吊舱训练模拟器的建模与仿真

介绍构建某型吊舱训练模拟器的建模和仿真方法．重点研究系统实现三维建模和交互式控制技术等关键问题的解决方案．对研发其他装备的虚拟仿真训练系统具有一定的借鉴意义。     

基于虚拟现实的煤矿大型设备培训系统研究

针对煤矿设备操作培训中存在的不足,设计并实现了一种基于虚拟现实技术的煤矿大型设备虚拟培训系统,利用三维建模软件Maya对井下主要设备采煤机、液压支架、刮板输送机等生产机械设备进行三维模型的创建,结合虚拟现实制作软件Unity3D进行虚拟场景整合与交互设计,利用C#编程语言实现对煤矿大型设备运动仿真控制.通过接口电路实现用户与虚拟场景设备的真实交互.经测试表明,系统不仅实现了煤矿大型设备操作培训的功能,而且增加了系统的交互性,弥补了传统培训方式的不足,节约了培训成本,缩短了培训周期.     

基于DirectSound的三维声音的仿真设计及实现

三维声音仿真是虚拟环境的一个重要组成部分。分析了利用D irectSound实现在虚拟环境中三维声音实时仿真的关键技术,并通过V isual C++6.0平台编程实现三维声音效果的播放。     

Efficient and Accurate Sound Propagation Using Adaptive Rectangular Decomposition

Accurate sound rendering can add significant realism to complement visual display in interactive applications, as well as facilitate acoustic predictions for many engineering applications, like accurate acoustic analysis for architectural design (Monks et al., 2000). Numerical simulation can provide this realism most naturally by modeling the underlying physics of wave propagation. However, wave simulation has traditionally posed a tough computational challenge. In this paper, we present a technique which relies on an adaptive rectangular decomposition of 3D scenes to enable efficient and accurate simulation of sound propagation in complex virtual environments. It exploits the known analytical solution of the wave equation in rectangular domains, and utilizes an efficient implementation of the discrete cosine transform on graphics processors (GPU) to achieve at least a 100-fold performance gain compared to a standard finite-difference time-domain (FDTD) implementation with comparable accuracy, while also being 10-fold more memory efficient. Consequently, we are able to perform accurate numerical acoustic simulation on large, complex scenes in the kilohertz range. To the best of our knowledge, it was not previously possible to perform such simulations on a desktop computer. Our work thus enables acoustic analysis on large scenes and auditory display for complex virtual environments on commodity hardware.     

A PC-based distributed multiple display virtual reality system

In this paper, a PC-based distributed multiple-display virtual reality system is constructed. The system is a PC-based CAVE environment. Five PCs are used in this system; one is the master responsible for receiving user's input signals, the others are clients for images rendering. Devices are added to synchronize the RGB signals from client PCs.

A software library is developed to drive the system properly. The software is designed in object-oriented language and flexibility for different interface devices is considered.

With the proposed system, developers can easily elaborate PC-based virtual reality applications and build PC virtual worlds at much lower cost.     

Using virtual reality technology for aircraft visual inspection training: presence and comparison studies

The aircraft maintenance industry is a complex system consisting of several interrelated human and machine components. Recognizing this, the Federal Aviation Administration (FAA) has pursued human factors related research. In the maintenance arena the research has focused on the aircraft inspection process and the aircraft inspector. Training has been identified as the primary intervention strategy to improve the quality and reliability of aircraft inspection. If training is to be successful, it is critical that we provide aircraft inspectors with appropriate training tools and environment. In response to this need, the paper outlines the development of a virtual reality (VR) system for aircraft inspection training.

VR has generated much excitement but little formal proof that it is useful. However, since VR interfaces are difficult and expensive to build, the computer graphics community needs to be able to predict which applications will benefit from VR. To address this important issue, this research measured the degree of immersion and presence felt by subjects in a virtual environment simulator. Specifically, it conducted two controlled studies using the VR system developed for visual inspection task of an aft-cargo bay at the VR Lab of Clemson University. Beyond assembling the visual inspection virtual environment, a significant goal of this project was to explore subjective presence as it affects task performance. The results of this study indicated that the system scored high on the issues related to the degree of presence felt by the subjects. As a next logical step, this study, then, compared VR to an existing PC-based aircraft inspection simulator. The results showed that the VR system was better and preferred over the PC-based training tool.     

A multi-regional computation scheme in an AR-assisted in situ CNC simulation environment

Computer numerical control (CNC) simulation systems based on 3D graphics have been well researched and developed for NC tool path verification and optimization. Although widely used in the manufacturing industries, these CNC simulation systems are usually software-centric rather than machine tool-centric. The user has to adjust himself from the 3D graphic environment to the real machining environment. Augmented reality (AR) is a technology that supplements a real world with virtual information, where virtual information is augmented on to real objects. This paper builds on previous works of integrating the AR technology with a CNC machining environment using tracking and registration methodologies, with an emphasis on in situ simulation. Specifically configured for a 3-axis CNC machine, a multi-regional computation scheme is proposed to render a cutting simulation between a real cutter and a virtual workpiece, which can be conducted in situ to provide the machinist with a familiar and comprehensive environment. A hybrid tracking method and an NC code-adaptive cutter registration method are proposed and validated with experimental results. The experiments conducted show that this in situ simulation system can enhance the operator’s understanding and inspection of the machining process as the simulations are performed on real machines. The potential application of the proposed system is in training and machining simulation before performing actual machining operations.