Real-time simulation for a virtual reality-based MIG welding training system

This paper describes a real-time welding simulation method for use in a desktop virtual reality simulated Metal Inert Gas welding training system. The simulation defines the shape of the weld bead, the depth of penetration, and the temperature distribution in the workpiece, based on inputs from the motion-tracking system that tracks the position of the welding gun as a function of time. A finite difference method is used to calculate the temperature distribution, including the width of the weld bead and the depth of penetration. The shape of the weld bead is then calculated at each time step by assuming a semi-spherical volume, based on the width of the weld bead, the welding speed, and the wire feed rate. The real-time performance of the system is examined, and results from the real-time simulation are compared to physical tests and are found to have very good correlation for welding speeds up to 1,000 mm/min.     

Landmine detection training simulation using virtual reality technology

Virtual Reality - Landmines are frequently used for defence and attack. Thus, landmine detection is vital to preventing the damages incurred. Various landmine detection methods have been developed...     

装备虚拟维修训练系统工程研究

以虚拟现实技术为基础,提出了装备虚拟维修训练系统建设总体方案,并完成了第一期的建设任务。该系统的实现,对于解决目前存在的复杂装备维修训练问题有重要意义。     

虚拟喷泉的计算机生成技术

介绍粒子系统和水波的物理学特性,研究生成模拟喷泉、水波、浪花及泡沫的理论基础．用粒子系统模拟喷泉、浪花及泡沫．实验证明该方法在生成速度和图像上都能获得非常好的效果．     

"虚拟仿真综合实训"课程融入思政内容设计

采用纵向和横向两条线进行"虚拟仿真综合实训"课程思政内容设计.纵向即按照实训的不同阶段来安排思政内容,横向即按照实训的不同主体单位来安排思政内容.对"虚拟仿真综合实训"课程思政教育教学体系的探索,必将使学生在学习专业技能的同时不断提高自身思想政治水平,真正成为德才兼备的新时代人才.     

A novel virtual reality simulation training system with haptic feedback for improving lateral ventricle puncture skill

Virtual Reality - The lateral ventricle puncture is an important step of external ventricular drain. It is one of the most basic but challenging skills that must be mastered by physicians. For...     

虚拟培训中的虚实联动技术

针对传统培训方式的不足,提出了虚实联动的培训方式.通过构建虚拟设备,硬件可编程逻辑控制器(PLC)、PC、虚拟设备三者之间的通信,实现虚拟设备和实体设备之间的联系,并且通过现场控制系统采集实体设备运行数据,将实体设备运行和故障等信息在虚拟设备中实时表现出来,拓展了虚拟培训的新思路.以喷印机虚拟联动系统为例论述了虚拟联动技术的必要性和可行性.     

Human-systems interaction for virtual environment team training

Virtual environments are increasingly used to support collaborative activities and distance learning. However, few are designed to support students, instructors and simulations in multi-participant team training. This paper describes the Training Studio, a system for authoring, delivering and evaluating multi-participant team training in an immersed virtual environment. The Training Studio focuses on human-systems interaction, allowing multiple students to learn and perform team tasks. The Training Studio supports collaborative learning for either single or multi-participant activity. This is accomplished through the use of agents which are assigned to students to act as personal mentors or missing team members. Conducting team training within a virtual environment introduces complexities and issues unique to team training and multiple-participant virtual environments. This paper describes our approach to virtual environment team training, discussing issues confronted and resulting design considerations and implementations.     

虚拟人环境感知的仿真方法研究

针对目标驱动的追击问题,将视线升维为柱体的视线筒,提出了一种虚拟人环境感知的筒视线方法.根据虚拟人所处的环境和行进速度,以变频方式、周期性地向目标发射筒视线,根据该筒视线与环境中障碍物的各碰撞点的信息和预先设置的行动推理知识库,确定虚拟人的追逐行动;为不完全可知的、动态虚拟环境中的目标追击问题提供了一种新的解决方案.该方案抛开了基于传统视野范围的拟人方式,以通过性的感知为中心,形成虚拟世界的互动性感知标准,建立虚拟人自身的感知功能,取得了更加逼真的仿真效果.原型系统验证了该方法的可行性和有效性.     

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.     

A large-scale complex virtual environment for team training

Virtual environments that allow multiple participants to cooperatively interact present complex design problems. In this article, we describe the Close Combat Tactical Trainer (CCTT), a joint US Army-Loral project, which is the first fully distributed interactive simulation (DIS)-compliant training system development effort. This Army program's approach relies successfully on concurrent engineering, spiral development and usability engineering     

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.     

Dynamic translation for virtual machine based traffic simulation

For virtual machine based traffic simulation platforms, the paper proposes a software framework that performs trace-based dynamic translation. Through monitoring the runtime execution status of bytecodes and translating frequently executed bytecodes, also known as hot spots, into equivalent native machine codes, the framework considerably improves the performance of virtual machine based traffic simulation platforms up to ten times or more, as the experiments showed. For the first time, the presented work clearly exhibits that a seamless combination of the two technologies – dynamic translation and virtual machine could lead to a new generation of applicable traffic simulation platforms. Such a platform not only offers high flexibility in terms of traffic model simulation, but also preserves the ability of conducting numerical computation-intensive simulations generally found in real-life industrial projects.     

Physical simulation of wet clothing for virtual humans

We present a technique that simulates wet garments for virtual humans with realistic folds and wrinkles. Our approach combines three new models to allow realistic simulation of wet garments: (1) a simplified saturation model that modifies the masses, (2) a nonlinear friction model derived from previously reported, real-world measurements, and (3) a wrinkle model based on imperfection sensitivity theory. In contrast to previous approaches to wet cloth, the proposed models are supported by the experimental results reported in the textile literature with parameters varying over the course of the simulation. As a result, the wet garment motions simulated by our method are comparable to that of real wet garments. Our approach recognizes the special, practical importance of contact models with human skin and provides a specific skin-cloth friction solution. We evaluate our approach by draping a rotating sphere and simulating a typical garment on a virtual human in the rain. Both of these examples are typical scenarios within computer graphics research.     

虚拟样机仿真标准化技术研究

虚拟样机标准化技术是实现大型复杂虚拟样机系统集成的根本前提,提出了虚拟样机仿真标准的制定原则,研究了虚拟样机仿真标准的主要内容,包括信息建模标准、信息交换标准、信息处理标准、信息安全标准、信息传输标准及人机界面标准等,虚拟样机标准化的研究可为虚拟样机技术的实现及进一步的应用研究提供基础。     

Haptic palpation for medical simulation in virtual environments

Palpation is a physical examination technique where objects, e.g., organs or body parts, are touched with fingers to determine their size, shape, consistency and location. Many medical procedures utilize palpation as a supplementary interaction technique and it can be therefore considered as an essential basic method. However, palpation is mostly neglected in medical training simulators, with the exception of very specialized simulators that solely focus on palpation, e.g., for manual cancer detection. In this article we propose a novel approach to enable haptic palpation interaction for virtual reality-based medical simulators. The main contribution is an extensive user study conducted with a large group of medical experts. To provide a plausible simulation framework for this user study, we contribute a novel and detailed interaction algorithm for palpation with tissue dragging, which utilizes a multi-object force algorithm to support multiple layers of anatomy and a pulse force algorithm for simulation of an arterial pulse. Furthermore, we propose a modification for an off–the–shelf haptic device by adding a lightweight palpation pad to support a more realistic finger grip configuration for palpation tasks. The user study itself has been conducted on a medical training simulator prototype with a specific procedure from regional anesthesia, which strongly depends on palpation. The prototype utilizes a co-rotational finite-element approach for soft tissue simulation and provides bimanual interaction by combining the aforementioned techniques with needle insertion for the other hand. The results of the user study suggest reasonable face validity of the simulator prototype and in particular validate medical plausibility of the proposed palpation interaction algorithm.