Augmented-Reality Survey: from Concept to Application <s> Hybrid-based approaches <s> Transferring research from the laboratory to mainstream applications requires the convergence of people, knowledge, and conventions from divergent disciplines. Solutions involve more than combining functional requirements and creative novelty. To transform technical capabilities of emerging mixed reality (MR) technology into the mainstream involves the integration and evolution of unproven systems. For example, real-world applications require complex scenarios (a content issue) involving an efficient iterative pipeline (a production issue) and driving the design of a story engine (a technical issue) that provides an adaptive experience with an after-action review process (a business issue). This article describes how a multi-disciplinary research team transformed core MR technology and methods into diverse urban terrain applications. These applications are used for military training and situational awareness, as well as for community learning to significantly increase the entertainment, educational, and satisfaction levels of existing experiences in public venues. <s> BIB001 </s> Augmented-Reality Survey: from Concept to Application <s> Hybrid-based approaches <s> Although Augmented Reality technology was first developed over forty years ago, there has been little survey work giving an overview of recent research in the field. This paper reviews the ten-year development of the work presented at the ISMAR conference and its predecessors with a particular focus on tracking, interaction and display research. It provides a roadmap for future augmented reality research which will be of great value to this relatively young field, and also for helping researchers decide which topics should be explored when they are beginning their own studies in the area. <s> BIB002 </s> Augmented-Reality Survey: from Concept to Application <s> Hybrid-based approaches <s> Magnetic compasses and accelerometers provide absolute orientation measurements within the earth's reference frame. However, sensor output typically suffers from jitter and external disturbances. Conversely, visual tracking provides more stable orientation estimation relative to an unknown initial orientation rather than to true north. We propose a 3-degree-of-freedom orientation tracking approach combining the accuracy and stability of vision tracking with the absolute orientation from inertial and magnetic sensors by estimating the offset between the initial orientation of the vision tracker and true north. We demonstrate that the approach improves absolute orientation estimation on a mobile phone device. <s> BIB003 </s> Augmented-Reality Survey: from Concept to Application <s> Hybrid-based approaches <s> 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. <s> BIB004 </s> Augmented-Reality Survey: from Concept to Application <s> Hybrid-based approaches <s> In the context of a smart user assistance system for industrial manipulation tasks it is necessary to capture motions of the upper body and limbs of the worker in order to derive his or her interactions with the task space. While such capturing technology already exists, the novelty of the proposed work results from the strong requirements of the application context: The method should be flexible and use only on-body sensors, work accurately in industrial environments that suffer from severe magnetic disturbances, and enable consistent registration between the user body frame and the task space. Currently available systems cannot provide this. This paper suggests a novel egocentric solution for visual-inertial upper-body motion tracking based on recursive filtering and model-based sensor fusion. Visual detections of the wrists in the images of a chest-mounted camera are used as substitute for the commonly used magnetometer measurements. The on-body sensor network, the motion capturing system, and the required calibration procedure are described and successful operation is shown in a real industrial environment. <s> BIB005
For the hybrid-based methods, the data from multiple sensors are used, and the accuracy and weaknesses of the individual sensors are enhanced. Since the vision-based tracking methods include the jitter and drift problems, one of the objectives of the hybrid system is a reduction of the drawbacks of the vision-based approaches BIB002 . Although the hybrid-based methods provide a robust tracking, the development of its system remains difficult. The hybrid-tracking systems, however, provide relatively sound solutions despite the increasing of the tracking complexity by these systems that is owing to the respective limitations of each sensor-tracking system. For the hybrid tracking, both the sensor-based tracking and the vision-based tracking are combined, or multiple sensors are used to compensate for the limitations of each technique. The hybrid-tracking approaches represent the most-promising method for both the indoor and the outdoor mobile AR applications BIB001 . Schall et al. presented a hybrid-tracking system for which the vision-based tracking is combined with the inertial and magnetic sensors BIB003 . Their approach considerably improved the absolute-orientation estimation on mobile devices. Bleser et al. also presented a hybrid system for which the egocentric-vision approach is combined with the inertial sensors to track the upper-body motion BIB005 . Carmigniani et al. BIB004 compared the common tracking technologies, as shown in Table 5 . 