Handheld Augmented Reality Indoor Navigation with Activity-Based Instructions Alessandro Mulloni, Hartmut Seichter, Dieter Schmalstieg Institute for Computer Graphics and Vision Graz University of Technology, Austria [ mulloni | seichter | schmalstieg ]@icg.tugraz.at (A) (B) (C) (D) (E) Figure 1. Screenshots of our application. (A): As a user stops at an info point, detailed augmented-reality information is presented as a World-in-Miniature (WIM). (B): As she starts walking, the interface presents sketchy information on the current activity, and directional information as a perspective arrow. (C-D): As she stops at the next info point, the WIM is again shown. From afar (C), it appears as a 2D map. The target office room is now visible, marked with a red flag. From closer, tilted perspectives (D), it is possible to examine the path in 3D. After leaving the info point (E), the interface presents again sketchy information on the activity. ABSTRACT We present a novel design of an augmented reality interface to support indoor navigation. We combine activity-based instructions with sparse 3D localisation at selected info points in the building. Based on localisation accuracy and the users’ activities, such as walking or standing still, the interface adapts the visualisation by changing the density and quality of information shown. We refine and validate our design through user involvement in pilot studies. We finally present the results of a comparative study conducted to validate the effectiveness of our design and to explore how the presence of info points affects users’ performance on indoor navigation tasks. The results of this study validate our design and show an improvement in task performance when info points are present, which act as confirmation points and provide an overview of the task. Author Keywords Augmented reality, indoor navigation, activity-based navigation. ACM Classification Keywords H.5.1 [Information interfaces and presentation]: Multimedia Information Systems – Artificial, augmented, and virtual realities. H.5.2 [Information interfaces and presentation]: User Interfaces. General Terms Design, Experimentation. INTRODUCTION Most augmented reality (AR) systems for indoor navigation are based on the assumption of continuous localisation of the user and require either a significant effort to instrument the environment with the necessary infrastructure, or sensor-based estimates of user movement in the environment. A large amount of research in AR focuses on improving the localisation technology, for example by increasing accuracy or reducing drift. In contrast, few studies investigate the feasibility of indoor navigation with sparse localisation. For practical reasons, cost and time effective deployment of sparse infrastructure allows one to exploit such a solution in large-scale indoor scenarios. Yet, while AR indoor navigation systems that use sparse localisation provide detailed augmented cues at selected info points, they often outsource the burden of navigating between info points to the user [18]. Copyright is held by the author/owner(s). MobileHCI 2011, Aug 30–Sept 2, 2011, Stockholm, Sweden. ACM 978-1-4503-0541-9/11/08-09....$10.00.