A Study On Augmented Reality Systems Catering To Operation Guidance

Augmented Reality (AR) is a modern technique, which can merge virtual information into real world without any conflict when observed by a display device. It combines real and virtual objects within a single real environment, runs interactively in real time, provides auxiliary information such like texts or animations to users, and tries not to introduce any disturbance against the real environment. As AR technique offers intuitive interactions and relatively simple design requirements, it attracts more and more attentions from researchers all over the world. Now AR has been applied to many different areas including entertainment, medical attendance, business, education, military, manufacture, and so on. Among these applications there is one kind of systems such like maintenance guidance, industrial training, surgery simulation and so on, which are designed to guide operators in their work by showing various virtual guidance information. In this thesis, we defined this kind of systems as Augmented Reality systems catering to operation guidance. Since AR develops so fast in recent years, much more attentions have been made on this subject, and many similar systems have been developed. But most researches still concertrate on how to apply or improve AR’s enabling techniques such as registration and interation, while few has worked on general system frameworks or information organization.From the perspective of general system frameworks, this thesis analyzed potential technical challenges that are concerned in AR systems catering to operation guidance. Herein, techniques such as vision based registration, conflict management among multimodal interactions, formal modeling of each technical modules, complex information organization and retrieval, are studied int this thesis, and meanwhile a general framework with careful details of every particulars in AR systems catering to operation guidance is proposed as a paradigm. Two prototype systems were developed to demonstrate these techniques and principles.All in all, the main contributions of this thesis are listed as follows:·A nature feature registration algorithm based on color distribution is proposed. The algorithm takes colorful connected areas as invariant features, calculates their descriptors simply by hue and geometry information, and matches them by global optimization based on geometric constraints on color distribution under undefined view transformations. The algorithm doesn’t rely on complex features and textures. It is suitable for most environments except those who have uniform color almost everywhere. Experimental results demonstrate the efficiency and effectiveness of the proposed algorithm, which runs in real-time with good precision robustly.· A general system framework of AR systems catering to operation guidance system is proposed. The framework establishes a general design theory and a common functional division. Every specific functional module is arranged to satisfy a special function of the system, and each of them are designed in careful detail. Hope this general framework can provide basic principles of design and accomplishment of such systems.· High level Petri net is applied to build the formal model of the general framework including every functional module. The model confirms the workflow, defines the specific I/O relations, and offers basic software architecture. A Petri net-based strategy to handle the conflict caused by multimodal interations is also proposed, which provides effective solution to manage this unstable problem.· A novel data design layout is proposed to organize the complex data involved in AR systems catering to operation guidance. The layout is an extended design based on S1000D international specification for technical publications. It formulates four original types of data module, and establishes their own XML schemas with retrieval rules. Markup samples are given to test the ability of this layout, which demonstrates linking registration and interaction information directly to procedural and guidance data module is a efficient way to keep system running in real time.