配电线路维护机器人虚拟现实仿真系统设计

针对配电线路维护机器人遥显示和在线作业轨迹规划的应用需要,设计了一套机器人虚拟现实三维仿真系统.通过将机械臂姿态信息实时传输到虚拟现实环境中,实现了作业场景3D遥显示功能;根据机器人带电作业需求,设计了一种基于虚拟现实环境的机械臂轨迹规划运动学仿真软件,可在三维虚拟空间测试机械臂作业路径的可行性,具有直观、安全和高效的...     

基于三维输入设备的虚拟场景控制方法

在视景仿真中能够精确地控制虚拟场景中的对象模型是增强系统交互性的重要手段。该文分析了虚拟场景中三维模型对象和视点的控制方法，重点介绍了基于3D输入设备的对象控制方法。在详细分析3D输入没备SpaceBall4000的特点、工作原理和应用技术的基础上，在VC -Vega—Creator一体化建模仿真开发环境中基于该3D输入设备实现了虚拟场景中三维模型对象和视点的6自由度精确控制，提供了应用三维输入设备控制虚拟场景的一种方法。     

虚拟手抓握动作的Petri网模型及其仿真实现

虚拟手的运动建模是三维人机交互研究中的一个关键问题.虚拟人在执行维修作业的过程中,不可避免地需要徒手抓握操作对象或维修工具.为此,该文提出了一种基于位置/变迁Petri网的虚拟人手抓握动作模型.该方法以关节化虚拟手的几何建模和关节约束分析为基础,描述了抓握动作的Petri网模型,通过仿真循环叠代和关节插值计算,实现关节链上各个关节的运动控制,并基于面向对象的技术设计实现了典型抓握动作.最后,基于人体建模与仿真软件Jack,设计并实现了一个虚拟手抓握动作的Petri网,仿真和实验结果表明所述方法简便易行,能够满足虚拟维修作业的要求.     

VDVAS：一个集成的虚拟设计与虚拟装配系统

随着虚拟现实技术的逐渐成熟，研究者们已将其引入到工程领域，为实现虚拟设计与虚拟装配过程的集成，避免现有的虚拟装配系统中，虚拟环境与CAD系统间所必需进行的复杂的、无谓的数据传输，描述了一个基于多通道的、集成的虚拟设计与虚拟装配系统VDVAS。在该系统中，设计得可以通过直接三维操作和语音命令直观方便地建立机械零件及其装配模型，并通过交互拆装来得到零件的装配顺序和装配路径等信息，VDVAS的一个重要特征在于，可通过集成虚拟设计与虚拟装配过程，使设计者能在一个集成的虚拟环境中修改零件几何（假如在装配过程中发现零件存在设计缺陷的话）。     

The integration of modular fixture database, fixturing knowledge base and 3-D fixture planning interface

The objective of this project is to present a computer aided fixturing system (CAFS), which integrates modular fixture database, fixture positions knowledge base and 3-D graphic display interface. The system will automatically select and layout the fixture elements to secure a workpiece through an interactive progress. This work can be sub-divided into three tasks. The first task is to build a modular fixture element database. The second task is to determine true positions of modular fixture elements given a set of fixture points, called fixture configuration. The third task is to provide a 3-D graphic interface to display and refine the fixture plan interactively. The system will be developed on the platform of a solid modeler, I-DEAS. Using this platform, the user can graphically rearrange fixture elements to refine the fixture plan.     

Head-Tracked Stereo Viewing with Two-Handed 3 D Interaction for Animated Character Construction

In this paper, we demonstrate how a new interactive 3 D desktop metaphor based on two-handed 3 D direct manipulation registered with head-tracked stereo viewing can be applied to the task of constructing animated characters. In our configuration, a six degree-of-freedom head-tracker and CrystalEyes shutter glasses are used to produce stereo images that dynamically follow the user head motion. 3 D virtual objects can be made to appear at a fixed location in physical space which the user may view from different angles by moving his head. To construct 3 D animated characters, the user interacts with the simulated environment using both hands simultaneously: the left hand, controlling a Spaceball, is used for 3 D navigation and object movement, while the right hand, holding a 3 D mouse, is used to manipulate through a virtual tool metaphor the objects appearing in front of the screen. In this way, both incremental and absolute interactive input techniques are provided by the system. Hand-eye coordination is made possible by registering virtual space exactly to physical space, allowing a variety of complex 3 D tasks necessary for constructing 3 D animated characters to be performed more easily and more rapidly than is possible using traditional interactive techniques. The system has been tested using both Polhemus Fastrak and Logitech ultrasonic input devices for tracking the head and 3 D mouse.     

Study on interaction-induced symptoms with respect to virtual grasping and manipulation

Owing to the popularity of various hand tracking interfaces, there have been numerous applications developed to provide intuitive hand interaction with the virtual world. As users start with great anticipation, they end up with dissatisfaction due to difficulties of manipulation or physical tiredness coming very short. Although the task itself is rather trivial in a real life situation, it requires much effort in the virtual environment. We address this awkwardness as ‘VR interaction-induced fatigue symptom’ and hypothesize its causes based on our observations. We argue that the source of the fatigue comes from the restricted sensory information of the VR interfaces, and that users try to accommodate the missing sensory feedback by excessive motion leading to wrong posture or bad timing. We demonstrate our hypothesis by conducting experiments of two types of virtual interaction scenarios: object transport and 3D selection. Furthermore, by analyzing the behaviors of users' action collected from our experiment, we derive essential factors to be considered in designing VR applications, and propose a conceptual interaction model for orchestrating virtual grasping.     

基于Web的虚拟物流实验室设计与实现

通过对虚拟物流实验室设计特点的分析,提出了基于Web的虚拟物流实验室构架,并设计了实现方案.运用3D 软件结合VRML建立虚拟场景模型,通过Java 3D对模型文件的调用实现虚拟场景的构建.调用Java 3D类库实现场景漫游、人机交互等功能,并对虚拟模型进行优化、重组.最后建立一个虚拟实验室的场景实例,验证了该设计方法具有良好的开发效率以及系统的沉浸性与交互性.     

一个基于Java3D的协同虚拟环境工作平台

协同虚拟环境为多用户构造一个可以沉浸其中漫游的虚拟空间,并支持用户之间的协同活动。在军事模拟、远程教育、娱乐等领域有广泛的应用。Java3D是一种高层3D API,可用于快速构建虚拟现实系统。尝试用Java3D技术构造一个协同虚拟环境工作平台原型系统,重点介绍了开发中的技术问题, 讨论了场景建模、消息通信、人机交互、化身控制、白板管理和视频显示等主要功能,并给出了一些具有较高参考价值的代码。     

Intuitive robot teleoperation for civil engineering operations with virtual reality and deep learning scene reconstruction

Robotic teleoperation, i.e., manipulating remote robotic systems at a distance, has gained its popularity in various industrial applications, including construction operations. The key to a successful teleoperation robot system is the delicate design of the human-robot interface that helps strengthen the human operator’s situational awareness. Traditional human-robot interface for robotic teleoperation is usually based on imagery data (e.g., video streaming), causing the limited field of view (FOV) and increased cognitive burden for processing additional spatial information. As a result, 3D scene reconstruction methods based on point cloud models captured by scanning technologies (e.g., depth camera and LiDAR) have been explored to provide immersive and intuitive feedback to the human operator. Despite the added benefits of applying reconstructed 3D scenes in telerobotic systems, challenges still present. Most 3D reconstruction methods utilize raw point cloud data due to the difficulty of real-time model rendering. The significant size of point cloud data makes the processing and transfer between robots and human operators difficult and slow. In addition, most reconstructed point cloud models do not contain physical properties such as weight and colliders. A more enriched control mechanism based on physics engine simulations is impossible. This paper presents an intelligent robot teleoperation interface that collects, processes, transfers, and reconstructs the immersive scene model of the workspace in Virtual Reality (VR) and enables intuitive robot controls accordingly. The proposed system, Telerobotic Operation based on Auto-reconstructed Remote Scene (TOARS), utilizes a deep learning algorithm to automatically detect objects in the captured scene, along with their physical properties, based on the point cloud data. The processed information is then transferred to the game engine where rendered virtual objects replace the original point cloud models in the VR environment. TOARS is expected to significantly improve the efficiency of 3D scene reconstruction and situational awareness of human operators in robotic teleoperation.     

分布式地学虚拟环境研究

讨论了分布式地学虚拟环境的概念,特征以及与GIS的相互关系,从系统结构,数据模型,交互界面和开发工具方面,对分布式地学虚拟环境的系统框架进行了研讨。最后,从理论,技术和应用层面介绍了关于分布式地学虚拟环境的研究热点和难点,并讨论了进一步的研究方向。     

Generating 3D interaction techniques by identifying and breaking assumptions

Researchers have created 3D interaction techniques for immersive virtual worlds, but existing techniques represent just part of the design space. While exploring other parts of the design space might yield more effective techniques, conducting that exploration is difficult and time-consuming. Analyzing the particular task, user, and hardware characteristics for any given problem is straightforward, but only suggests the shape of a potential technique; generating the technique itself still requires a creative breakthrough. We propose extending existing approaches to generating 3D interaction techniques by focusing more explicitly on identifying and breaking assumptions about the real world to inspire potential technique ideas. We describe our approach, suggest an initial list of assumptions to consider, and present a case study of applying the process to create a technique for navigation with visible landmarks and place representations.     

A hierarchically structured and constraint-based data model for intuitive and precise solid modeling in a virtual reality environment

This article proposes a hierarchically structured and constraint-based data model for intuitive and precise solid modeling in a virtual reality (VR) environment. The data model integrates a high level constraint-based model for intuitive and precise manipulation, a middle level solid model for complete and precise representation and a low-level polygon mesh model for real-time interactions and visualization in a VR environment. The solid model is based on a hybrid B-rep/CSG data structure. Constraints are embedded in the solid model and are organized at hierarchical levels as feature constraints among internal feature elements, part constraints among internal features and assembly constraints between individual parts. In addition to providing a complete and precise model representation and the support for real-time visualization, the proposed data model permits intuitive and precise interaction through constraint-based manipulations for solid modeling in a VR environment. This is a critical issue for product design in a VR environment due to the limited resolutions of today's VR input and output devices.     

Automated modular fixture planning: Geometric analysis

Attendant Processes such as fixture and die design are often a necessary but time-consuming and expensive component of a production cycle. Coupling such attendant processes to product design via feature-based CAD will lead to more responsive and affordable product design and redesign. In the context of on-going research in automating fixture configuration design, this paper presents a fundamental study of automated fixture planning with a focus on geometric analysis. The initial conditions for modular fixture assembly are established together with geometric relationships between fixture components and the workpiece to be analyzed. Of particular focus is the design of alternative locating points and components, together with examples of 3-D fixture designs.     

Automated modular fixture planning: Accuracy, clamping, and accessibility analyses

Attendant Processes such as fixture and die design are often a necessary but time-consuming and expensive component of a production cycle. Coupling such attendant processes to product design via feature-based CAD will lead to more responsive and affordable product design and redesign. In the context of on-going research in automating fixture configuration design, this paper presents a fundamental study of automated fixture planning with a focus on geometric analysis. The initial conditions for modular fixture assembly are established together with geometric relationships between fixture components and the workpiece to be analyzed. Of particular focus is the design of alternative locating points and components, together with examples of 3-D fixture designs.     

Integration Model of Eye-Gaze, Voice and Manual Response in Multimodal User Interface

This paper reports the utility of eye-gaze,voice and manual response in the design of multimodal user interface.A device-and application-independent user interface model(VisualMan)of 3D object selection and manipulation was developed and validated in a prototype interface based on a 3D cube manipulation task.The multimodal inpus are integrated in the prototype interface based on the priority of modalities and interaction context.The implications of the model for virtual reality interface are discussed and a virtual environment using the multimodal user interface model is proposed.     

Interactive Construction and Animation of Layered Elastically Deformable Characters

An interactive system is described for creating and animating deformable 3D characters. By using a hybrid layered model of kinematic and physics-based components together with an immersive 3D direct manipulation interface, it is possible to quickly construct characters that deform naturally when animated and whose behavior can be controlled interactively using intuitive parameters. In this layered construction technique, called the elastic surface layer model, a simulated elastically deformable skin surface is wrapped around a kinematic articulated figure. Unlike previous layered models, the skin is free to slide along the underlying surface layers constrained by geometric constraints which push the surface out and spring forces which pull the surface in to the underlying layers. By tuning the parameters of the physics-based model, a variety of surface shapes and behaviors can be obtained such as more realistic-looking skin deformation at the joints, skin sliding over muscles, and dynamic effects such as squash-and-stretch and follow-through. Since the elastic model derives all of its input forces from the underlying articulated figure, the animator may specify all of the physical properties of the character once, during the initial character design process, after which a complete animation sequence can be created using a traditional skeleton animation technique. Character construction and animation are done using a 3D user interface based on two-handed manipulation registered with head-tracked stereo viewing. In our configuration, a six degree-of-freedom head-tracker and CrystalEyes shutter glasses are used to display stereo images on a workstation monitor that dynamically follow the user head motion. 3D virtual objects can be made to appear at a fixed location in physical space which the user may view from different angles by moving his head. To construct 3D animated characters, the user interacts with the simulated environment using both hands simultaneously: the left hand, controlling a Spaceball, is used for 3D navigation and object movement, while the right hand, holding a 3D mouse, is used to manipulate through a virtual tool metaphor the objects appearing in front of the screen. Hand-eye coordination is made possible by registering virtual space to physical space, allowing a variety of complex 3D tasks necessary for constructing 3D animated characters to be performed more easily and more rapidly than is possible using traditional interactive techniques.     

HVS：一种基于实景图象的虚拟现实系统

大多数的虚拟现实比试在于计算机图形技术,先由多边形构造虚拟场景的三维几何模型,再由计算机根据用户的观察点和观察方向实时绘制出用户所看到的虚拟场景,ＨＶＳ 另一种思路,由计算机自动拉接、变形与组织许多幅度散的实景图象或连续视频,生成虚拟场景,这种虚拟场人有照片质量的视觉效果,被我们称为虚拟实景空间,虚拟实时空间能为用户提供、后退、仰视、俯视、３６０度环境、近看、远看等漫游能力,运行它不需要高性能的图