户外增强现实系统的关键技术研究

增强现实技术,特别是户外增强系统,近年来已经成为一大研究热点。论文研究了增强现实中的主要技术,分析了户外增强现实系统的关键技术,就听觉增强方面的未来发展等提出了自己的见解。     

基于增强现实的机器人远程控制系统研究

虚拟现实技术的应用使远程控制系统得到发展,增强现实技术是虚拟现实技术的拓展,它将计算机生成的虚拟物体叠加到用户感知的真实世界中.提出并实现了一种基于增强现实的机器人远程控制系统,并就其结构和关键技术进行详细的说明,实验及运行结果表明该系统能有效地改善人机交互能力,并能提高远程控制的精度.     

Tracking for augmented reality on wearable computers

Wearable computers afford a degree of mobility that makes tracking for augmented reality difficult. This paper presents a novel object-centric tracking architecture for presenting augmented reality media in spatial relationships to objects, regardless of the objects' positions or motions in the world. The advance this system provides is the ability to sense and integrate new features into its tracking database, thereby extending the tracking region automatically. A lazy evaluation of the structure from motion problem uses images obtained from a single calibrated moving camera and applies recursive filtering to identify and estimate the 3D positions of new features. We evaluate the performance of two filters; a classic Extended Kalman Filter (EKF) and a filter based on a Recursive-Average of Covariances (RAC). Some implementation issues and results are discussed in conclusion.     

增强现实系统中的摄像机校准算法研究

增强现实系统的关键技术之一是精确定位问题,当用户改变他/她的观察视点时,虚拟对象必须与真实对象的运动方向与位置保持一致,这样才能使用户感觉到虚拟对象融入到真实环境中.而要做到这一点,就必须研究摄像机校准问题.在这篇文章中,我们分析了增强现实系统对摄像机校准算法的要求,给出了一个实用的摄像机校准算法,并且对算法的结果进行了具体分析.     

Tangled reality

Leonardo da Vinci was a strong advocate for using sketches to stimulate the human imagination. Sketching is often considered to be integral to the process of design, providing an open workspace for ideas. For these same reasons, children use sketching as a simple way to express visual ideas. By merging the abstraction of human drawings and the freedom of virtual reality with the tangibility of physical tokens, Tangled Reality creates a rich mixed reality workspace. Tangled Reality allows users to build virtual environments based on simple colored sketches and traverse them using physical vehicles overlayed with virtual imagery. This setup allows the user to “build” and “experience” mixed reality simulations without ever touching a standard computer interface.     

智能手机的移动增强现实技术研究

随着增强现实技术的快速发展以及智能手机技术的革新,移动增强现实(M-AR)技术得以脱离体积庞大的PC机设备的限制,使其向户外和无线化发展成为可能,并由此推动了增强现实技术在智能手机上的应用。针对智能手机的移动增强现实技术在应用发展中所要解决的问题,进行了分析和探讨,较为系统地阐述了该领域最新的发展状况,并展望了该技术未来的发展前景。     

Automotive technicians' training as a community-of-practice: implications for the design of an augmented reality teaching aid

The paper presents an ergonomic analysis carried out in the early phases of an R&D project. The purpose was to investigate the functioning of today's Automotive Service Technicians (ASTs) training in order to inform the design of an Augmented Reality (AR) teaching aid. The first part of the paper presents a literature review of some major problems encountered by ASTs today. The benefits of AR as technological aid are also introduced. Then, the methodology and the results of two case studies are presented. The first study is based on interviews with trainers and trainees; the second one on observations in real training settings. The results support the assumption that today's ASTs' training could be regarded as a community-of-practice (CoP). Therefore, AR could be useful as a collaboration tool, offering a shared virtual representation of real vehicle's parts, which are normally invisible unless dismantled (e.g. the parts of a hydraulic automatic transmission). We conclude on the methods and the technologies to support the automotive CoP.     

Modelling and design of an augmented reality differential drive mobility aid in an enabled environment

In this paper the authors discuss the modelling and design of an augmented reality platform for disabled wheeled mobility studies. This design consists of a virtual environment with two degrees of freedom motion platform and integrated ground contact force feedback. Differential drive mobility users continue to be in touch with reality on their own mobility aid while interacting with virtual objects. The major domain related to the differential drive mobility of the disabled members of society which coincides with the use of manual wheelchairs, electric wheelchairs and mobility scooters. In order to account for environmental and dynamic effects, the wheeled mobility user needs to map the intended trajectory into the virtual world. Motion and inertia force feedback produced on the augmented simulator give the users a haptic sensory stimulus input regarding spatial movement and ground contact forces. The main objective is to model and design an augmented reality platform with real world kinematic and dynamic properties to place a wheeled mobility user closer to real world encounters. The use of the designed augmented reality platform will be beneficial to disabled wheeled mobility users in need of occupational therapist training and evaluation.     

一种增强现实系统的三维注册方法

三维注册技术是增强现实系统研究的一个重要方面。现有的增强现实技术三维注册方法都是用平面标志来作为定位基准的,且系统构造较复杂,图象处理所需计算量较大,还会因此引入误差。该文提出了一种使用立体标志物的基于视觉的三维注册方法。该方法只需要一个彩色ＣＣＤ摄像机就可以完成三维环境注册,并且不需要进行复杂的图象处理运算,这种新方法能够有效简化注册系统和算法,并且能消除使用多个传感器的配合误差。     

Automatic generation and detection of highly reliable fiducial markers under occlusion

This paper presents a fiducial marker system specially appropriated for camera pose estimation in applications such as augmented reality and robot localization. Three main contributions are presented. First, we propose an algorithm for generating configurable marker dictionaries (in size and number of bits) following a criterion to maximize the inter-marker distance and the number of bit transitions. In the process, we derive the maximum theoretical inter-marker distance that dictionaries of square binary markers can have. Second, a method for automatically detecting the markers and correcting possible errors is proposed. Third, a solution to the occlusion problem in augmented reality applications is shown. To that aim, multiple markers are combined with an occlusion mask calculated by color segmentation. The experiments conducted show that our proposal obtains dictionaries with higher inter-marker distances and lower false negative rates than state-of-the-art systems, and provides an effective solution to the occlusion problem.     

Optically based direct manipulation for augmented reality

Augmented reality (AR) constitutes a very powerful three-dimensional user interface for many “hands-on” application scenarios. To fully exploit the AR paradigm, the computer must not only augment the real world, but also accept feedback from it. In this paper, we present an optical approach for collecting such feedback by analyzing video sequences to track users and the objects they work with. Our system can be set up in any room after quickly placing a few known optical targets in the scene. We present two demonstration scenarios to illustrate the overall concept and potential of our approach and then discuss the research issues involved.     

Lessons learned on the way to industrial augmented reality applications, a retrospective on ARVIKA

This paper presents and discusses the results of the project ARVIKA. After a short introduction and presentation of the project goals, the augmented reality system is described. It consists in a Plug-In for internet-browser in which all the software components have been integrated. The advantages and disadvantages of the adopted approaches, as well as the lessons learned from the project are presented in details. Finally, the open issues are discussed and future work to be achieved until a possible implementation of augmented reality in an industrial context is proposed.     

Human factors and qualitative pedagogical evaluation of a mobile augmented reality system for science education used by learners with physical disabilities

Technology-enhanced learning, employing novel forms of content representation and education service delivery by enhancing the visual perception of the real environment of the user, is favoured by proponents of educational inclusion for learners with physical disabilities. Such an augmented reality computer-mediated learning system has been developed as part of an EU funded research project, namely the CONNECT project. The CONNECT project brings together schools and science centres, and produces novel information and communication technologies based on augmented reality (AR) and web-based streaming and communication, in order to support learning in a variety of settings. The CONNECT AR interactive learning environment can assist users to better contextualize and reinforce their learning in school and in other settings where people learn (i.e. science centres and home). The CONNECT concept and associated technologies encourage users to visit science centres and perform experiments that are not possible in school. They can also build on these experiences back at school and at home with visual augmentations that they are communicated through web-based streaming technology. This paper particularly focuses on a user-centred evaluation approach of human factors and pedagogical aspects of the CONNECT system, as applied to a special needs user group. The main focus of the paper is on highlighting the human factors issues and challenges, in terms of wearability and technology acceptance, while elaborating on some qualitative aspects of the pedagogical effectiveness of the instructional medium that AR technology offers for this group of learners.