Augmented Reality (AR) is increasingly considered for use in real industrial applications [8]. In our industrial research lab at Siemens Technology, we are continuously discussing suitable AR scenarios in business sectors involving power plants, wind turbine plants, and oil and gas factories. We have developed a company-internal AR system architecture, Hololayer, which provides AR facilities in a reusable manner to development engineers such that they can build their own AR applications for their specialized use cases. The integration of AR technology into industrial processes encounters many complex issues: we need to adhere to many safety, security and quality guarantees while also adapting quickly to the rapidly changing state of the art of AR devices (HMDs, tablets). To increase flexibility, it might be good to integrate Hololayer with one of the open frameworks that have recently been proposed [11], [29], [38]. Yet, care must be taken when converting an already existing, large company-owned framework like Hololayer to such platforms. Some of the proposed standardized APIs and communication protocols may be difficult to abide by, without requiring significant rewriting efforts or even violating company-internal regulations. In this paper, we report on our efforts to combine Hololayer with one such platform, Ubi-Interact [38]. This is a collaboration between Siemens technology and the FAR group at TU Munich. After exemplary descriptions of typical application scenarios, we present the underlying principles of Hololayer to support this range of applications. We then describe rudimentary concepts of Ubi-Interact, followed by an elaboration on the efforts to combine both systems for a selected application scenario and a discussion of the results achieved thus far.

To create a common understanding of a software system, for users and developers, we believe that run-time visualization of both behavior and internal structure is critical. This is particularly true for distributed embedded systems, which are designed to be unobtrusive, making them difficult to comprehend for people who are not familiar with them. We suggest a novel method to visualize software behavior in real-time flexibly and comfortably, facilitating understanding of software. We conducted a feasibility study with a proof of-concept prototype. Our results indicate that visualizing structure and behavior in real-time supports software comprehension for new architects, developers and users, and can even provide new insights to experienced developers.

Augmented reality (AR) provides a natural interface to the "calm" pervasive technology anticipated in large-scale ubiquitous computing environments. However, the range of classic AR applications has been limited by the scope, range and cost of sensors used for tracking. Hybrid tracking approaches can go some way to extending this range. We propose an approach, called ubiquitous tracking, in which data from widespread and diverse heterogeneous tracking sensors is automatically and dynamically fused, and then transparently provided to applications. A formal model represents spatial relationships between objects as a graph attributed with quality-of-service parameters. This paper presents a software implementation, in which a dynamic data flow network of distributed software components is thereby constructed in response to queries and optimisation criteria specified by applications. This implementation is demonstrated using a small laboratory example, and larger setups modelled in a simulation environment.

In the past, architectures of augmented reality systems have been widely different and tailored to specific tasks. In this paper, we use the example of the SHEEP game to show how the structural flexibility of DWARF, our component-based distributed wearable augmented reality framework, facilitates a rapid prototyping and online development process for building, debugging and altering a complex, distributed, highly interactive AR system. The SHEEP system was designed to test and demonstrate the potential of tangible user interfaces which dynamically visualize, manipulate and control complex operations of many inter-dependent processes. SHEEP allows the users more freedom of action and forms of interaction and collaboration, following the tool metaphor that bundles software with hardware in units that are easily understandable to the user. We describe how we developed SHEEP, showing the combined evolution of framework and application, as well as the progress from rapid prototype to final demonstration system. The dynamic aspects of DWARF facilitated testing and allowed us to rapidly evaluate new technologies. SHEEP has been shown successfully at various occasions. We describe our experiences with these demos.

Research prototypes in AR usually do not emphasize software architecture. Nevertheless, their architecture is not arbitrary, but results from specific needs. Architectural approaches embodying research contributions are of particular value for reuse at component and architectural levels. We have conducted a study of existing AR software architectures for the ARVIKA project by W. Friedrich et al (2001). This has resulted in a catalog of important desired quality attributes for AR systems, a reference architecture for comparison of AR architectures, and a catalog of architectural approaches used in current AR systems. We believe this lays the foundation for further research in AR software architectures.