Evaluating the Benefits of Augmented Reality for Task Localization in Maintenance of an Armored Personnel Carrier Turret Steven J. Henderson Steven Feiner Columbia University* ABSTRACT We present the design, implementation, and user testing of a pro- totype augmented reality application to support military mechan- ics conducting routine maintenance tasks inside an armored ve- hicle turret. Our prototype uses a tracked head-worn display to augment a mechanic’s natural view with text, labels, arrows, and animated sequences designed to facilitate task comprehension, location, and execution. A within-subject controlled user study examined professional military mechanics using our system to complete 18 common tasks under field conditions. These tasks included installing and removing fasteners and indicator lights, and connecting cables, all within the cramped interior of an ar- mored personnel carrier turret. An augmented reality condition was tested against two baseline conditions: an untracked head- worn display with text and graphics and a fixed flat panel display representing an improved version of the laptop-based documenta- tion currently employed in practice. The augmented reality condi- tion allowed mechanics to locate tasks more quickly than when using either baseline, and in some instances, resulted in less over- all head movement. A qualitative survey showed mechanics found the augmented reality condition intuitive and satisfying for the tested sequence of tasks. KEYWORDS: maintenance, service, repair, attention, localization augmented reality * {henderso,feiner}@cs.columbia.edu INDEX TERMS: H.5.1 [Information Interfaces and Presentation]: Multimedia Information Systems—Artificial, augmented and virtual realities; H.5.2 [Information Interfaces and Presentation]: User Interfaces—Training, help, and documentation 1 INTRODUCTION Maintenance and repair operations represent an interesting and opportunity-filled problem domain for the application of aug- mented reality. The majority of activities in this domain are con- ducted by trained maintenance personnel applying established procedures to documented designs in relatively static and predict- able environments. These procedures are typically organized into sequences of quantifiable tasks targeting a particular item in a specific location. These characteristics and others form a well- defined design space, conducive to a variety of systems and tech- nologies that could assist a mechanic in performing maintenance. Physically navigating these tasks, however, can be extremely time consuming and requires significant head and neck movement when transitioning between tasks. Maintenance sequences can also be difficult to traverse cognitively because they require me- chanics to first position a given task in a presumed model of the environment and then correctly identify this location in the physi- cal world. This problem is particularly acute when maintaining complex systems, such as those found in industrial, military, and aerospace domains. Maintenance sequences in such systems typi- cally span dozens of tasks involving potentially unfamiliar objects randomly distributed across a given area. Moreover, movement in and around these systems can be complicated by their shear size or by structural characteristics that restrict a mechanic’s view and freedom of movement. In this paper, we examine and document how augmented reality (AR) can assist in reducing the time and effort in navigating larger Figure 1: (Left) A mechanic wearing a tracked head-worn display performs a maintenance task inside an LAV-25A1 armored personnel carrier. (Right) The AR condition in the study: A view through the head-worn display captured in a similar domain depicts information pro- vided using augmented reality to assist the mechanic. (The view through the head-worn display for the LAV-25A1 domain was not cleared for publication due to security restrictions, necessitating the substitution of images from an alternative domain throughout this paper.) 135 IEEE International Symposium on Mixed and Augmented Reality 2009 Science and Technology Proceedings 19 -22 October, Orlando, Florida, USA 978-1-4244-5389-4/09/$25.00 ©2009 IEEE