Experiments with Face-To-Face Collaborative AR Interfaces

We describe a design approach, Tangible Augmented Reality, for developing face-to-face collaborative Augmented Reality (AR) interfaces. Tangible Augmented Reality combines Augmented Reality techniques with Tangible User Interface elements to create interfaces in which users can interact with spatial data as easily as real objects. Tangible AR interfaces remove the separation between the real and virtual worlds, and so enhance natural face-to-face communication. We present several examples of Tangible AR interfaces and results from a user study that compares communication in a collaborative AR interface to more traditional approaches. We find that in a collaborative AR interface people use behaviours that are more similar to unmediated face-to-face collaboration than in a projection screen interface.     

Augmented reality technologies,systems and applications

This paper surveys the current state-of-the-art of technology, systems and applications in Augmented Reality. It describes work performed by many different research groups, the purpose behind each new Augmented Reality system, and the difficulties and problems encountered when building some Augmented Reality applications. It surveys mobile augmented reality systems challenges and requirements for successful mobile systems. This paper summarizes the current applications of Augmented Reality and speculates on future applications and where current research will lead Augmented Reality’s development. Challenges augmented reality is facing in each of these applications to go from the laboratories to the industry, as well as the future challenges we can forecast are also discussed in this paper. Section 1 gives an introduction to what Augmented Reality is and the motivations for developing this technology. Section 2 discusses Augmented Reality Technologies with computer vision methods, AR devices, interfaces and systems, and visualization tools. The mobile and wireless systems for Augmented Reality are discussed in Section 3. Four classes of current applications that have been explored are described in Section 4. These applications were chosen as they are the most famous type of applications encountered when researching AR apps. The future of augmented reality and the challenges they will be facing are discussed in Section 5.     

The impact of engineering information format on task performance: Gaze scanning pattern analysis

The emergence of new visualization technologies such as Virtual Reality (VR) and Augmented Reality (AR) had been widely implemented in the Architecture, Engineering, and Construction (AEC) industry. Although cumulative evidence pointed out a positive impact of these visualization technologies on construction task performance, there is still an obvious disagreement on the benefits or implications of these new visualization technologies, due to the lack of understanding of the mechanisms in which the visualization affects cognitive processes related to information processing. To obtain more evidence, this paper presents a human-subject experiment (n = 90) to investigate the impact of information format on the performance of an industrial pipeline maintenance task. The investigation centers around how different engineering information formats affect the attention patterns as a potential explanation for the changes in performance. A between-group experiment design was used where the participants were randomly assigned to one of the three groups (2D group, 3D group, and VR group) depending on what type of information was given to review the pipe operation instruction. After the review session, the participants were asked to perform the operation task in the virtual environment based on their memory. The results showed that the 3D and VR groups outperformed the 2D group in task performance. The analysis of eye-tracking data further indicated that the information format significantly changed the gaze scanning pattern when participants were reviewing the operational instructions. We also found that the task performance was correlated with eye-tracking features including gaze movement and pupil dilation. Our findings provided more evidence about the mechanisms in which new visualization technologies affect the attention patterns, helped resolve the current disagreement within the literature. In addition, a prediction model was proposed to use eye-tracking features to predict construction task performance.     

Nonoverlapped view management for augmented reality by tabletop projection

Augmented reality (AR) by a projector allows for the easy association of information by labeling the objects. When a projector is installed above a workspace and pointed downward, supportive information can be presented; however, the label will be deformed if the object is nonplanar. Also, a label might be projected in a region where it is hidden by the object, i.e., a blind area. In this paper, we propose a view management technique to allow interpretation by improving the legibility of the information. We propose the nonoverlapped gradient descent (NGD) method, which determines the position of a newly added label by avoiding overlap with the surrounding labels and linkage lines. The issues of presenting in a shadow or blind area are also addressed by estimating these areas based on the approximation of objects as a simple solid. The results of an experiment show that the visibility of the labels was improved by using this method.     

Augmented reality projects in the automotive and aerospace industries

The 2003 International Symposium on Mixed and Augmented Reality was accompanied by a workshop on potential industrial applications. The organizers wisely called it potential because the real use of augmented reality (AR) in an industrial context is still in its infancy. Our own experience in this field clearly supports this viewpoint. We have been actively involved in the research, development, and deployment of AR systems in the automotive, aviation, and astronautics industries for more than five years and have developed and implemented AR systems in a wide variety of environments while working at DaimlerChrysler in Germany. In this article we have selected 10 AR projects from those we have managed and implemented in the past to examine the main challenges we faced and to share some of the lessons we learned.     

基于ARToolKit的地下管网增强现实系统研究

增强现实是把计算机生成的虚拟图像或其它信息叠加到用户所看到的真实世界中的一种技术,是虚拟现实领域的一个难点热点。ARToolKit为增强现实技术的应用提供了一种方便快捷的开发工具,但其不足之处在于它是基于计算机视觉的注册方式,不适合户外增强现实系统的开发,需要做进一步的改进。论文利用ARToolKit在室内实现了管网三维可视化的增强显示,取得了满意的效果;根据户外的实际,提出了以全球定位系统载波相位差分(GPSRTK)和惯性导航系统(INS)相结合进行精确定位、以电子罗盘和倾角计相结合测定视线方向的混合注册方法;对利用ARToolKit建立户外地下管网增强现实系统的框架及功能作了进一步的探讨。     

Extended overview techniques for outdoor augmented reality

In this paper, we explore techniques that aim to improve site understanding for outdoor Augmented Reality (AR) applications. While the first person perspective in AR is a direct way of filtering and zooming on a portion of the data set, it severely narrows overview of the situation, particularly over large areas. We present two interactive techniques to overcome this problem: multi-view AR and variable perspective view. We describe in details the conceptual, visualization and interaction aspects of these techniques and their evaluation through a comparative user study. The results we have obtained strengthen the validity of our approach and the applicability of our methods to a large range of application domains.     

增强现实技术综述

增强现实技术是将计算机渲染生成的虚拟场景与真实世界中的场景无缝融合起来的一种技术,它通过视频显示设备将虚实融合的场景呈现给用户,使人们与计算机之间的交互更加的自然,同时具有广泛的应用前景,因此成为近年来的一个研究热点。随着跟踪注册技术的进步、计算机性能的飞速发展、深度摄像机的普及,以及Light Field投影技术在增强现实中的应用,增强现实技术逐渐成为下一代人机交互的发展方向。该文章首先概述了增强现实的主要研究内容和发展情况,并详细介绍了增强现实的关键技术、开发工具,然后分类概述了增强现实应用案例。     

A review of augmented reality visualization methods for subsurface utilities

Subsurface utilities are important assets that need to be perceived during any construction activities. Positioning and visualizing the subsurface utilities before the construction work starts has significant benefits for the effective management of construction projects. Augmented Reality (AR) is a promising technology for the visualization of subsurface utilities. The aim of this paper is to provide a comprehensive review of the state-of-the-art in AR visualization of subsurface utilities, including existing AR visualization methods, categorization of the methods and their drawbacks, comprehensive discussion on the challenges, research gaps and potential solutions. The paper begins with an introduction of current practice of locating subsurface utilities and an overview of different reality technologies including AR. We propose a taxonomy of AR visualization methods including X-Ray view, transparent view, shadow view, topo view, image rendering and cross-section view. We provide a comparison of existing methods in terms of quality of depth perception, occlusion of real world, complexity of visualization and parallax effect followed by a discussion of the drawbacks in these methods. Poor depth perception, parallax effect caused by the user movement, poor positional accuracy in Global Navigation Satellite System (GNSS) deprived or indoor areas and unavailability of accurate location information for generating virtual models are identified as main challenges and topics of future research in effective AR visualization of subsurface utilities.     

Collaborative visualization of engineering processes using tabletop augmented reality

3D computer visualization has emerged as an advanced problem-solving tool for engineering education and practice. For example in civil engineering, the integration of 3D/4D CAD models in the construction process helps to minimize the misinterpretation of the spatial, temporal, and logical aspects of construction planning information. Yet despite the advances made in visualization, the lack of collaborative problem-solving abilities leaves outstanding challenges that need to be addressed before 3D visualization can become widely accepted in the classroom and in professional practice. The ability to smoothly and naturally interact in a shared workspace characterizes a collaborative learning process. This paper introduces tabletop Augmented Reality to accommodate the need to collaboratively visualize computer-generated models. A new software program named ARVita is developed to validate this idea, where multiple users wearing Head-Mounted Displays and sitting around a table can all observe and interact with dynamic visual simulations of engineering processes. The applications of collaborative visualization using Augmented Reality are reviewed, the technical implementation is covered, and the program’s underlying tracking libraries are presented.     

智能手机增强现实关键技术研究

将增强现实技术应用到智能手机上,实现增强现实系统的小型化和便携化,会大大拓展和深化增强现实系统应用的广度和深度。当前对于智能手机增强现实技术的研究,一般采用基于计算机视觉（即视频检测）的注册方式。首次提出了在智能手机上采用GPS/三维电子罗盘的注册方法,研究微型三维电子罗盘与智能手机的软、硬件接口,从底层开发并实现具有增强现实功能的软件模块,建立基于智能手机的空间信息三维可视化模型算法,并以三维管线为例进行实证研究,结果表明基于空间信息的智能手机增强现实构建的技术路线是可行的。     

增强现实:特点、关键技术和应用

增强现实(Augmented Reality，AR)技术将计算机生成的虚拟对象与真实世界进行融合，构造出虚实结合的虚拟空间增强现实系统有三个特点：真实和虚拟结合，实时交互，真实和虚拟对象进行定位构造一个AR系统要解决许多关键技术，包括显示技术，跟踪和定位技术，界面技术以及标定技术另外AR系统还要充分考虑人的因素AR技术在许多方面都有潜在的应用价值，如医疗，机械维护和修理，注释，协同，商业以及军事应用等本文对这些问题进行论述，最后讨论为使AR广泛使用需要解决的一些问题。     

一种新型的交互式增强现实系统

增强现实是随着虚拟现实技术的发展而衍生小来的。它抒计算机产生的虚拟物体合成到真实环境当中。本文采用ARToolKit系统作为开发环境,Open Dynamic Engille（ODE）为动力学引擎以及利用Open Scene Graph（OSG）图形引擎开发包,将增强现实技术与碰撞检测技术相结合实现了一种新型的交互式增强现实系统。     

A virtual-physical collision detection interface for AR-based interactive teaching of robot

At present, online lead-through and offline programming methods are widely used in programming of industrial robots. However, both methods have some drawbacks for unskilled shopworkers. This paper presents an Augmented Reality (AR)-based interactive robot teaching programming system, which virtually projected the robot onto the physical industrial environment. The unskilled shopworkers can use Handheld Teaching Device (HTD) to move end-effector of virtual robot to follow endpoint of the HTD. In this way, the path of the virtual robot can be planned or tested interactively. In addition, collisions detection between virtual robot and physical environment is key to test the feasibility of robot path. So, a method for detecting virtual-physical collisions is presented in this paper by comparing the depth values of corresponding pixels in depth image acquired by Kinect and computer-generated image in order to get collision-free paths of the virtual robot. The Quadtree model is used to accelerate the collision detection process and get distance between virtual model and physical environment. Using the AR-based interactive robot teaching programming system presented in this paper, all workers even unskilled ones in robot programming, can quickly and effectively get the collision-free robot path.     

一种基于视沉的增强现实三维注册算法

为了提高增强现实系统三维注册的精度和效率，提出了一种基于计算机视觉的增强现实三维注射算法，并已将其用于采用透射式头盔显示器的增强现实系统中，该算法有如下特点：（1）构架简单，实用性强，一般情况下只需4个平面标志物就可实现三维注册；（2）工作范围大，甚至可以应用到室外的增强现实系统中；（30数值求解过程最线性过程，误差小，可以满足增强现实系统高精度三维注册的要求，另外，应用这种算法所需要作的图象处理计算量很小，其典型系统包括一个彩色CCD和几个不同颜色的标志点，由于很容易获得标志点的对应像面位置，而且不需要计算图象对，因此实时性好，是一般图形工作站和PC机上的增强现实系统进行实时注册的算法基础。     

Analytic review of usability evaluation in ISMAR

There has been a rapid increase in research evaluating usability of Augmented Reality (AR) systems in recent years. Although many different styles of evaluation are used, there is no clear consensus on the most relevant approaches. We report a review of papers published in International Symposium of Mixed and Augmented Reality (ISMAR) proceedings in the past decade, building on the previous work of Swan and Gabbard (2005). Firstly, we investigate the evaluation goal, measurement and method of ISMAR papers according to their usability research in four categories: performance, perception and cognition, collaboration and User Experience (UX). Secondly, we consider the balance of evaluation approaches with regard to empirical–analytical, quantitative–qualitative and participant demographics. Finally we identify potential emphases for usability study of AR systems in the future. These analyses provide a reference point for current evaluation techniques, trends and challenges, which benefit researchers intending to design, conduct and interpret usability evaluations for future AR systems.     

An object expression system using depth-maps

The current of Augmented Reality are data gloves or markers used for interactions between object and background. But, this results in the inconvenience in use and reduced immersiveness. To reinforce immersiveness in AR, added input devices should be removed. To this end, spatial coordinates should be accurately perceived even when a marker has been attached. In this paper, an object expression system was proposed that uses depth-maps for interactions without any additional input devices in order to improve immersiveness. Immersiveness was improved by projecting obtained images on 2D spaces, extracting vanishing lines, calculating the virtual spatial coordinates of the projected images, and varying the sizes of the inserted objects in accordance with the sizes of the areas of virtual coordinates, based on the images projected on the 2D coordinates. By using this system, the use of 3D modelers could be excluded when 3D objects were created; thus, the efficiency of object creation could be improved.     

Intention to Use Mobile Augmented Reality in the Tourism Sector

This article examines the main variables that influence the intention to use Augmented Reality (AR) applications in the tourism sector in Jordan. The study model has been constructed based on the unified theory of acceptance and the use of technology2 (UTAUT2), by incorporating a new construct (aesthetics) to explore the usage intention of Mobile Augmented Reality in Tourism (MART). A questionnaire was used and distributed to a sample of 450 participants. Data were analyzed using the Smart PLS version 3.0. for testing 12 hypotheses. 29 measurement items were carefully reviewed based on previous studies that were selected to assess the research hypotheses. The findings revealed that the proposed model elucidates 35.7% of the variance in the users’ intention to use MART. The results also showed that both performance expectancy and aesthetics were found to be the most significant factors at level (0.001). Four variables, respectively, were at level (0.01) which consisted of social influence, facilitating conditions, hedonic motivation, and price value. The weakest effect was effort expectancy at level (0.05). As the use of AR has become important for tourists, this study establishes a research base that can be built upon for future researchers. MART developers can benefit from the results of this research to design and deliver this service successfully and to ensure that its adoption by users is achieved.     

Representing information – Classifying the Augmented Reality presentation space

Augmented Reality has a wide-ranging presentation space. In addition to presenting virtual information in a 3D space, such information can also be placed in relation to physical objects, locations or events.Decomposing this presentation space – or more exactly, the principles of how information is represented in Augmented Reality – into unique and independent dimensions provides a fundamental spectrum of options. First, this decomposition facilitates a fine-grained analysis of effects on human understanding. Second, multiple factors, given by multiple differences between different presentation systems with respect to more than one such principle, can be determined and properly addressed. Third, this decomposition facilitates a determination of new fields of research by identifying not-yet-used concepts.Since the beginning of Augmented Reality research, a growing number of applications have emerged that exploit various ways to represent information. This paper resumes this development and presents a set of independent dimensions covering representation principles of virtual information related to a physical environment: the temporality of virtual information, dimensionality, the frame of reference, mounting/registration and the type of reference. The suitability of the devised dimensions is tested by categorizing a wide variety of AR applications. The categorized data is analyzed for the most-often and less-frequently used combinations of classes. In particular, the classes that have not yet been used exhibit the potential to allow future work that investigates new options for information presentation.     

混合跟踪技术在增强现实系统中的应用

跟踪技术是增强现实的一个重要研究方向,它致力于解决虚拟信息与真实环境的精确配准问题,构建稳定、高效的增强现实系统。通过分析增强现实系统的跟踪需求,指出单一跟踪存在的不足,说明采用混合跟踪技术的必要性,论述了基于视觉一惯性的混合跟踪技术及其在增强现实中的应用,实现了一种基于VisTracker视觉-惯性混合跟踪器的增强现实实验系统,并给出调试结果。