Control of robot arm with virtual environment via the Internet

Many enterprises experience difficulty in training people to work with expensive equipment, which is needed for carrying out profitable work tasks (e.g., production line robots). Similar problems are found when work is of a complex and safety-critical nature (e.g., nuclear environments, explosive placement, surgery). A common problem faced by educational institutions concerns the limited availability of expensive robotics equipment, with which students in the didactic program can work, in order to acquire valuable "hands on" experience. This paper describes a method of education and training involving off-line usage of virtual reality environments for task planning. When tasks are developed to the satisfaction of the trainee, they are exported to remote physical hardware, via the Internet, for real-world execution. Development of the system and the training experiments is discussed, along with some of the issues raised for telerobotics and solutions to the problem of detecting collisions in the virtual world. The approach has been shown to be viable, and increases the education and training possibilities for key workers while maintaining a low cost of ownership. The downtime of mission critical equipment is minimized while the gaining of valuable experience is maximized.     

一种室内环境下机器人同时定位与地图构建方法

介绍了一种移动机器人室内环境下同时定位与地图构建方法，给出了整个系统的结构框图。将从激光传感信息中提取出的直线特征作为主要的环境描述特征，用EKF算法更新机器人位姿和直线特征的估计值，用一种新的数据关联方法以实现地图的最小描述。直线特征提取采改进的IE2F算法，能够快速地从数据点中得到较为精确的直线参数。实验证明整个系统具有良好的性能。     

A radio access system with distributed antennas

This paper analyzes a radio access system that has multiple antennas spatially distributed throughout each cell, instead of a single antenna at each cell. The same signal is simulcast by each antenna in the cell. The signals at a given cell could be multiplexed and modulated for radio transmission at a single node, then transmitted on a coaxial cable distribution system to and from the distributed antennas in a cell. Frequency translation and radio frequency (RF) amplification may need to be performed at each antenna, except for indoor applications with short coaxial cables. This paper presents calculations of signal-to-interference ratios (SIR) and handoff performance for cells with distributed antennas. It is shown that the use of distributed antennas can substantially increase the SIR above a system with a single antenna per cell, and this increase is quantified. It is also shown that increasing the number of antennas results in better overall handoff performance, with a lower number of handoffs and higher received signal power. Minimizing the number of handoffs will reduce the impact of wireless services on network elements     

基于虚拟现实技术的水体虚拟仿真替代式建模方法研究

本文简述了水体仿真的应用领域、特性及建模方法,并以虚拟系统中的瀑布仿真为例,为满足虚拟场景对真实性和实时性的需求,提出替代式的建模方式。文中阐述了替代式仿真构建的全过程,并通过多案例对比证实替代式建模方式的可行性和优越性。以替代式建模方法作为构建瀑布场景的主要方式,即用简单模型结合纹理贴图、粒子效果等形式替代复杂模型,在确保仿真效果的同时将复杂模型用最简化的方式表现出来,使虚拟场景在真实性和实时性两个方面都得到很好地表现。     

Measuring human–robot interaction on wearable robots: A distributed approach

This paper presents a novel, distributed approach to monitor physical interaction between a user and a wearable robot. We propose to apply a matrix of optoelectronic sensors embedded in a thin and compliant silicone bulk onto the user-robot contact surface. This distributed tactile sensor can measure the pressure distribution on the interaction area without affecting the comfort of the user, and does not require the robot to be specifically designed to house it. Besides the estimation of the interaction force/torque, the distributed approach allows to monitor the pressure on the user’s skin. This information is fundamental to assess the comfort and safety of the users which determine the final acceptability of the robot-mediated rehabilitation. The proposed method is preliminary evaluated on an elbow active orthosis during a repetitive rehabilitation task. Experimental results prove the relevance of this approach for the detection of the user motion intention through a measurement of the interaction force distribution.     

Modeling of a distributed access protocol for an ATM satellitesystem: an algorithmic approach

An algorithmic model for the performance evaluation of the medium access control (MAC) protocol for a satellite system in an asynchronous transfer mode (ATM) environment is presented. This model allows analysis of general load configurations and yields the mean value of the performance parameters (e.g. queue lengths and access delays). The model is based on a computer-oriented approach, and the characterization of the key model variables is obtained by means of an iterative procedure. A comparison of the model analysis results to those obtained by a simulative approach shows a satisfactory matching     

面向协同制造的分布式对象与虚拟设计环境研究

针对分布式在协同设计与制造环境中的需求,提出了实体对象与分布式对象的映射模型和平台匹配方案。分析了协同虚拟制造(CVM,collaborative virtual manufacturing)的技术体系,给出了实体对象的分析方法,提出了分布式环境下的分布式对象映射模型,并设计了CVM分布式支撑环境架构；引入单元匹配和平台匹配量化分析,改进了信息平台效率测度的评价方法。通过实例分析,得到了CVM系统结构拓展模型,对分布式虚拟设计与测试环节进行讨论,表明了应用协同与虚拟现实技术的改进效率。     

A student's perspective: getting real with virtual reality

As with many up and coming technologies, the road to wide acceptance is not always smooth. Virtual reality (VR) is one such technology whose bumpy ascent is well underway. VR is not all that new but the steady price/performance gains for computational power have helped it gain a broader base of applications and even a little popularity along the way. The author's current research is one example of how VR can be used as an analysis as well as a visualization tool. He is developing interactive scenarios where the user can pose "what if?" questions in a VR environment and the VR environment will respond with an array of possibilities. The user will then be able to experience and better assess the impacts of each alternative. The interactive aspects of VR make it an ideal platform for developing scenarios across a broad range of applications.     

虚拟现实环境下遗传算法在工业产品造型设计

虚拟现实环境下工业产品造型设计方向种类繁杂且多由人为操作,得到全局最优设计结果的速度不佳,因此,提出在虚拟现实环境下遗传算法在工业产品造型设计中的运用。通过层次化产品造型结构设计产品造型基因编码,利用适应度函数对个体进行适应值评价,确定编码个体适应度;由遗传算子支撑产品造型设计方案的进化,满足人工参与条件后在虚拟现实环境下由人工评估设计方案,直至产生用户满意的方案。实验结果显示,在相同条件下,基于遗传算法生成的工业产品造型设计结果较常规方法生成的设计结果少迭代410次,即可精确收敛到全局最优设计结果,表明虚拟现实环境下遗传算法在工业产品造型设计中收敛到全局最优结果速度更快,效果更佳。     

Navigation with auditory cues in a virtual environment

The authors use 3D sound to help navigate an immersive virtual environment and report results of user tests obtained with a game-like application. The results show that auditory cues help in navigation, and auditory navigation is possible even without any visual feedback. The best performance is obtained in audiovisual navigation where auditory cues indicate the approximate direction and visual cues help in the final approach.     

虚拟现实环境下的工业造型设计复杂问题求解优化

通过先进的人机交互方式,虚拟现实技术可以有效提高工业造型设计的工作效率。但是,工业产品的造型设计问题一般性质十分复杂,传统的优化方法很难实现该问题的求解。因此,提出一种基于虚拟现实技术和多目标遗传优化的工业造型设计系统。对采用的虚拟现实系统整体结构及其相关软硬件参数进行介绍。对产品造型设计的流程进行分析,并在产品造型设计中应用排序多目标遗传算法。软件开发语言为Visual C++6.0,并采用模拟开发软件Vega实现CAD数据转换。系统运行测试结果表明,所提出系统能够有效提高产品造型优化设计的质量、缩短设计周期。     

Haptics in virtual reality and multimedia

Imagine that you're chatting with a good friend who tells you about her new cashmere pullover, and that you're able to touch it and appreciate the soft sensation of the cashmere wool - remotely over the Web in your virtual chatroom! In this article, the authors present their work on haptic sensing of virtual textiles. This is work done in the context of the Haptex research project that aims at integrating the human sense of touch into multimodal user interfaces. Being able to support haptic perception in the user interface will be a great step toward next-generation immersive multimedia experiences.     

Scheduling with bus access optimization for distributed embeddedsystems

In this paper, we concentrate on aspects related to the synthesis of distributed embedded systems consisting of programmable processors and application-specific hardware components. The approach is based on an abstract graph representation that captures, at process level, both dataflow and the flow of control. Our goal is to derive a worst case delay by which the system completes execution, such that this delay is as small as possible; to generate a logically and temporally deterministic schedule; and to optimize parameters of the communication protocol such that this delay is guaranteed. We have further investigated the impact of particular communication infrastructures and protocols on the overall performance and, specially, how the requirements of such an infrastructure have to be considered for process and communication scheduling. Not only do particularities of the underlying architecture have to be considered during scheduling but also the parameters of the communication protocol should be adapted to fit the particular embedded application. The optimization algorithm, which implies both process scheduling and optimization of the parameters related to the communication protocol, generates an efficient bus access scheme as well as the schedule tables for activation of processes and communications     

Design and control of robot manipulator with a distributed actuation mechanism

This paper presents a design methodology based on the distributed actuation principle to achieve a high-performance robot manipulator. Spatial movement of the actuation points provides several advantages such as high payload capacity, high efficiency and a light weight structure for the proposed robot manipulator. Based on the analysis, the distributed actuation mechanism using a single slider is adopted for the proposed manipulator. A prototype of the manipulator with two degrees of freedom is developed and controlled as an example. The efficacy of the proposed approach is verified experimentally.     

Building a virtual community for a tele-learning environment

This article presents the results of a research project that requires students and faculty to evolve a virtual community in a university class. The concepts, requirements, and importance of a virtual community are discussed, along with the skill requirements necessary for students to participate effectively in a virtual community. The Web sites and class assignments that form the basis of a virtual community are described. Finally, the importance of enriching the learning experience and humanizing the learning process through the use of a virtual community is also discussed     

A neuro-fuzzy approach for robot system safety

Robot safety is a critical and largely unsolved problem involving the interaction of man and machine. The paper presents a new approach to robot safety which uses an integrated sensing architecture for monitoring the robot workspace, and a new detection and decision logic for regulating the safe operation of the robot. Sensory information is fused through a trained neural network to produce a map of the hazards. Using this combined map, and information about the robot's current position and velocity, a set of fuzzy logic rules has been implemented to regulate robot activity. Simulation results presented in the paper indicate that this method is both effective in detection of potentially hazardous situations and computationally feasible     

多机协同空战仿真分布式虚拟环境网络通信软件设计

针对一个基于分布虚拟环境技术设计的仿真平台，介绍了系统网络通信软件的设计思想，总体结构及对关键技术问题的分析和处理。     

Human-following mobile robot in a distributed intelligent sensor network

The robots that will be needed in the near future are human-friendly robots that are able to coexist with humans and support humans effectively. To realize this, humans and robots need to be in close proximity to each other as much as possible. Moreover, it is necessary for their interactions to occur naturally. It is desirable for a robot to carry out human following, as one of the human-affinitive movements. The human-following robot requires several techniques: the recognition of the target human, the recognition of the environment around the robot, and the control strategy for following a human stably. In this research, an intelligent environment is used in order to achieve these goals. An intelligent environment is a space in which many sensors and intelligent devices are distributed. Mobile robots exist in this space as physical agents providing humans with services. A mobile robot is controlled to follow a walking human using distributed intelligent sensors as stably and precisely as possible. The control law based on the virtual spring model is proposed to mitigate the difference of movement between the human and the mobile robot. The proposed control law is applied to the intelligent environment and its performance is verified by the computer simulation and the experiment.     

Bio-driven system-based virtual reality for prosthetic and rehabilitation systems

Current prosthetic and rehabilitation devices, used for those who are limbless or born with congenital defects or required rehabilitation, are difficult to use. The users have problems to adapt to their new hosts or receiving any bio-feedback despite rehabilitation process and retraining, particularly when working with electromyogram (EMG) signals. In characterizing virtual human limbs, as a potential prosthetic device in three dimensions (3D) virtual reality, patients are able to familiarize themselves with their new appendage and its capabilities or can see their movements’ intention in a Virtual Training Environment. This paper presents a virtual reality (VR)-based design and implementation of a below-shoulder 3D human arm capable of 10-class EMG-based motions driven system of biomedical EMG signal. The method considers a signal classification output as potential control stimulus to drive the virtual limb. A hierarchical design methodology is adopted based on anatomical structure to congruent with virtual reality modeling language (VRML) architecture used in order to progressively build the user interface model and its inherent functionality. The resulting simulation is based on a portable, self-contained VRML prototype implementation paired with an instrumental virtual control-select board capable of actuating any combinations of singular or paired kinematic of 10-class EMG motions. The simulation allows for multiple degree-of-freedom profiles as the classes can be activated independently, or in conjunction with others, allowing enhanced arm movement. Provisions for direct classified control inputs are built into the prototype for holistic system construction.     

虚拟现实在无人驾驶地铁中的应用浅析

虚拟现实(Virtual Reality,VR)在近几年来在消费电子领域得到迅猛发展,得到学术界、工业界的广泛关注.从虚拟现实发展背景入手,简单介绍虚拟现实的发展现状和技术发展趋势.同时,结合目前先进的无人驾驶地铁技术,探讨了虚拟现实在轨道交通行业中的典型应用,一方面为虚拟现实中的关键技术找到了新的实际应用,另一方面,为无人驾驶地铁中的系统工程问题提供了新的解决思路和技术方案.