增强现实技术在博物馆中的应用研究

增强现实是一种通过计算机将虚拟数据和现实环境相融合的技术,能够呈现给用户一种全新的交互模式,提高用户对真实世界存在元素的感知能力。随着计算机技术的发展,增强现实技术成为研究热点,并开始走进人们的生活,互联网技术和移动设备的迅速发展为其提供了一个广阔的舞台。传统的博物馆一般展览方式枯燥单一,展品虽多,但传达的信息量却很少。移动增强现实形式的博物馆展览通过蓝牙定位技术进行馆内导览,针对不同类型的展品选用二维码标识识别或者自然特征识别,在移动设备上将展品或展馆信息与虚拟信息进行叠加,从而增加展览的趣味性,使被动式的参观方式转变成互动式的参观方式,实现博物馆的多元化。     

基于增强现实的人机物理交互仿真系统研究

在增强现实系统中,真实物体和虚拟物体除了要实现视觉上的融合之外,还要能够实现视觉交互和物理交互.仿真系统采用了基于单目视觉的ARToolKit增强现实开发平台,首先对CMOS摄像头采集的图像进行处理,利用模式识别的方法对标识物进行图像匹配,然后对从标识物坐标系到摄像机坐标系的变换矩阵进行计算,实现虚实注册,最后通过对标识物空间位置的改变实现了虚实物体问的单向物理交互.实验结果表明,该系统操作简单直观,具有良好的实时性,交互性及可扩展性.     

基于投影技术的增强现实注册方法

注册技术是实现增强现实应用系统的关键问题之一。实现了一种利用投影技术改进了的注册方法。这种注册方法主要包含4个步骤：（1）检测标识和特征点的位置;（2）利用投影技术跟踪摄像机;（3）计算模型视图矩阵;（4）绘制虚拟物体。在初始阶段,指定4个点建立世界坐标系,虚拟物体将会被叠加到这个坐标系上;在注册过程中,利用投影技术跟踪特征点的位置,并计算用于增强的模型视图转换。这种注册方法可以为一般的室内增强现实系统提供所需的精确度和实时性。     

基于移动增强现实的智慧城市导览

提出一种采用移动增强现实技术实现智慧城市导览的方法,满足用户个性化、多尺度、按需推送的智能导览需求,呈现用户虚实融合的周边环境.移动终端计算性能以及资源存储能力有限,但集成多种传感器,方便携带,易于显示.利用服务器实现基于词汇树的海量场景识别定位系统.依据地理位置信息动态划分分区缩减了场景检索范围,基于二进制鲁棒尺度不变特征(binary robust invariant scalable keypoints,BRISK)进行层级式聚类提高了识别算法的实时性.移动终端利用服务器返回的识别结果进行BRISK特征与光流算法结合的混合特征跟踪注册方法,并通过点集映射消除特征点漂移,利用前后帧信息以及关键帧信息减少跟踪抖动.UKbench标准图像库以及真实环境下的实验结果表明,虚实融合的智能导览效果良好.该原型系统已成功应用于上海电信体验馆等展馆智能导览系统.     

基于图形变换的人体经络可视化

提出了一种可以检测并直观表示人体经络分布的实时定位和显示方法。首先,利用多通道经络阻抗检测仪和磁定位跟踪仪确定人体体表经络点的位置,获取经络点的三维信息;其次,对场景摄像机进行标定,并将其结果和经络点的三维信息通过图形变换技术变换到统一的世界坐标系下,获取摄像机的投影矩阵H;最后,根据该投影矩阵H,将经络点三维信息投影到二维图像上,形成二维经络线,并将其融合于场景摄像机拍摄的人体体表实时图像上,实现人体经络的可视化。测试结果表明,该方法能够准确有效地定位和显示人体经络。     

一种基于手眼标定的增强现实跟踪注册方法

手眼标定是机器人领域常用的一种确定机器人末端坐标系和摄像机坐标系之间相互关系的标定方法。跟踪和定位是增强现实研究的热点,跟踪定位通常为复合跟踪系统,结合多传感器跟踪信息,优势互补,达到更高测量精度和准确度。跟踪注册是实现信息有效融合的基本前提。文章将机器人手眼标定引入多传感器跟踪注册,并通过实验验证了这种基于手眼标定的跟踪注册方法的有效性。     

基于移动增强现实技术的纪念馆互动系统设计

移动增强现实(MAR)技术是人机交互技术发展的一个全新方向,它是将虚拟和现实结合的体现,具有实时互动的特性,解决了传统展览方式的单一性以及游客跟展品之间缺乏互动性的问题.本文以开发增强现实在纪念馆导览系统中的应用为载体,建立纪念馆MAR展品互动展示系统,将展品以多种形式展现给游客,探索新型的纪念馆导览方式.     

基于多视定位算法的多摄像机标定

针对多摄像机系统标定,提出一种基于多视定位算法的标定方法,标定过程只需一块可自由移动的平面模板即可,利用约束优化思想,将各摄像机坐标系转换到参考摄像机坐标系下,从而得到摄像机之间相对位置关系。标定操作过程简单,易于实现。实验结果表明,该方法是一种有效的多摄像机标定方法。     

基于移动增强现实技术的灾害和事故救援系统设计

设计了基于移动增强现实技术的灾害和事故救援系统,利用智能移动设备和移动网络构建了能实时采集现场真实信息并与虚拟图像进行融合的完整体系。根据不同的灾害种类,采用针对性的跟踪和注册算法,分别进行了地理定位、标识物识别和基于自然特征图像识别的研究,为救援人员节省了大量宝贵时间,便于营救工作快速高效的开展。     

增强现实与视觉惯导模块的位姿融合方法

基于视觉标志物的增强现实技术和视觉惯性里程计(VIO)技术有着良好的互补性。本文针对当前基于视觉标志物的增强现实系统依赖标志物以及VIO的缺乏地理位置信息、累计误差等问题,提出一种泛用的位姿融合方法,该方法可以将任意的2种不同坐标系下的相同轨迹位姿输出转换到同一坐标系下。针对本文的问题,实现基于视觉标志物的增强现实与视觉惯导模块的位姿融合,并利用视觉标志物自身带有地理信息的特点,为整个系统提供真实的地理信息坐标,使得定位系统能够与地理信息系统相结合。以实时通讯的方式采集华为P10手机输出的图像与IMU信息作为数据源,在Ubuntu16.04和Unity游戏引擎上进行实验。结果表明,本文方法能够有效地完成准确的位姿融合。     

采用计算机视觉进行室内飞艇定位的方法研究

采用单个摄像机进行定位时,需要设定图像中的特征点和实际物体特征点间的几何约束关系,建立数学方程,来获取摄像机坐标系中物体位置的封闭解,通过求解该方程获得物体在世界坐标下的三维位置。提出了利用单摄像机视觉定位技术于科技馆室内飞艇定位中,解决了科技馆室内飞艇自主航行的定位问题。实验表明,该方法简单易行,可用于工程实际应用中,具有较高的实用价值。     

On the precision of third person perspective augmented reality for target designation tasks

The availability of powerful consumer-level smart devices and off-the-shelf software frameworks has tremendously popularized augmented reality (AR) applications. However, since the built-in cameras typically have rather limited field of view, it is usually preferable to position AR tools built upon these devices at a distance when large objects need to be tracked for augmentation. This arrangement makes it difficult or even impossible to physically interact with the augmented object. One solution is to adopt third person perspective (TPP) with which the smart device shows in real time the object to be interacted with, the AR information and the user herself, all captured by a remote camera. Through mental transformation between the user-centric coordinate space and the coordinate system of the remote camera, the user can directly interact with objects in the real world. To evaluate user performance under this cognitively demanding situation, we developed such an experimental TPP AR system and conducted experiments which required subjects to make markings on a whiteboard according to virtual marks displayed by the AR system. The same markings were also made manually with a ruler. We measured the precision of the markings as well as the time to accomplish the task. Our results show that although the AR approach was on average around half a centimeter less precise than the manual measurement, it was approximately three times as fast as the manual counterpart. Additionally, we also found that subjects could quickly adapt to the mental transformation between the two coordinate systems.     

An assisting,constrained 3D navigation technique for multiscale virtual 3D city models

Virtual 3D city models serve as integration platforms for complex geospatial and georeferenced information and as medium for effective communication of spatial information. In order to explore these information spaces, navigation techniques for controlling the virtual camera are required to facilitate wayfinding and movement. However, navigation is not a trivial task and many available navigation techniques do not support users effectively and efficiently with their respective skills and tasks. In this article, we present an assisting, constrained navigation technique for multiscale virtual 3D city models that is based on three basic principles: users point to navigate, users are lead by suggestions, and the exploitation of semantic, multiscale, hierarchical structurings of city models. The technique particularly supports users with low navigation and virtual camera control skills but is also valuable for experienced users. It supports exploration, search, inspection, and presentation tasks, is easy to learn and use, supports orientation, is efficient, and yields effective view properties. In particular, the technique is suitable for interactive kiosks and mobile devices with a touch display and low computing resources and for use in mobile situations where users only have restricted resources for operating the application. We demonstrate the validity of the proposed navigation technique by presenting an implementation and evaluation results. The implementation is based on service-oriented architectures, standards, and image-based representations and allows exploring massive virtual 3D city models particularly on mobile devices with limited computing resources. Results of a user study comparing the proposed navigation technique with standard techniques suggest that the proposed technique provides the targeted properties, and that it is more advantageous to novice than to expert users.     

Exploring the use of handheld AR for outdoor navigation

Recently, mobile-phone based outdoor augmented reality (AR) systems have become readily available. One of the most popular applications are AR browsers that show virtual points of interest (POIs) overlaid on top of the phone's camera view. These virtual cues can be used to guide people to the POIs. However, the usefulness of AR systems for guiding users to POI has not yet been evaluated, especially when compared to map interfaces. In this paper we present results of a user study comparing navigation with information typically provided by currently available handheld AR browsers, to navigation with a digital map, and a combined map and AR condition. We found no overall difference in task completion time, but found evidence that AR browsers are less useful for navigation in some environment conditions. We also found that navigation performance differed significantly with gender for the Map and AR+Map interfaces, but is very similar across gender for the AR interface. Users preferred the combined AR+Map condition, and felt that there were significant problems with using the AR view alone for navigation.     

基于VI-SLAM的四翼无人机多目标视觉定位技术

针对传统多目标视觉定位技术定位误差大这一问题,基于VI-SLAM的四旋翼无人机提出了一种新的多目标视觉定位技术,阐述了定位技术原理,在进行定位时,导航定位系统、航空姿态测量系统、机载光电测量平台共同工作,通过多目标相机标定、锁定目标背景差分确定目标在摄像机坐标系的位置,将摄像机坐标系转换成载机机体坐标系,再将载机机体坐标系转换成大地坐标系,从而实现定位,引入北斗卫星导航系统和递归最小二乘算法降低定位误差。对比实验结果表明,相较于传统定位技术,基于VI-SLAM的四旋翼无人机的多目标视觉定位技术定位误差更小,应用性更广。     

基于云存储服务的AR博物馆系统研究

针对传统AR博物馆中资源不能有效利用、共享和管理的问题,构建了基于云存储服务的AR博物馆系统。该系统采用FAST-SURF算法对特征点进行检测,通过计算机视觉和无线相结合的方式进行跟踪匹配,同时利用云存储服务技术对博物馆资源进行管理,最终实现虚实融合显示。实例测试表明,与传统AR博物馆相比,该系统能够有效管理博物馆资源,且检测速度快、定位精度较高、匹配性好,特别是在实时性和稳定性方面有明显的优势。结果表明,借助云存储服务技术对AR博物馆资源进行管理的系统方案是可行的,可以为博物馆的研究提供新的技术支持。     

Gesture-based interactive augmented reality content authoring system using HMD

This paper proposes an augmented reality content authoring system that enables ordinary users who do not have programming capabilities to easily apply interactive features to virtual objects on a marker via gestures. The purpose of this system is to simplify augmented reality (AR) technology usage for ordinary users, especially parents and preschool children who are unfamiliar with AR technology. The system provides an immersive AR environment with a head-mounted display and recognizes users’ gestures via an RGB-D camera. Users can freely create the AR content that they will be using without any special programming ability simply by connecting virtual objects stored in a database to the system. Following recognition of the marker via the system’s RGB-D camera worn by the user, he/she can apply various interactive features to the marker-based AR content using simple gestures. Interactive features applied to AR content can enlarge, shrink, rotate, and transfer virtual objects with hand gestures. In addition to this gesture-interactive feature, the proposed system also allows for tangible interaction using markers. The AR content that the user edits is stored in a database, and is retrieved whenever the markers are recognized. The results of comparative experiments conducted indicate that the proposed system is easier to use and has a higher interaction satisfaction level than AR environments such as fixed-monitor and touch-based interaction on mobile screens.     

基于图像匹配的飞行器导航定位算法及仿真

在飞行器导航定位优化控制的研究中,针对无法获得GPS信号时,长航时飞行器捷联惯导系统存在误差,提出了关于图像地标的飞行器精确定位算法,为实现成像系统对捷联惯导系统的误差校正奠定了基础。利用特定地标在机载摄像机像平面上的图像信息,通过图像变换、匹配定位、坐标变换,解算摄像机空间三维坐标和三个姿态角。再根据摄像机坐标系与机体坐标系的变换关系,推算飞行器精确位置。通过计算机仿真对算法进行了验证,结果表明,提出的算法能够满足GPS不可用时长航的飞行器组合导航精度要求,研究结果对长航时飞行器导航具有一定借鉴和参考价值。