Dedicated object processor for mobile augmented reality - sailor assistance case study

摘要

This paper addresses the design of embedded systems for outdoor augmented reality (AR) applications integrated to see-through glasses. The set of tasks includes object positioning, graphic computation, as well as wireless communications, and we consider constraints such as real-time, low power, and low footprint. We introduce an original sailor assistance application, as a typical, useful, and complex outdoor AR application, where context-dependent virtual objects must be placed in the user field of view according to head motions and ambient information. Our study demonstrates that it is worth working on power optimization, since the embedded system based on a standard general-purpose processor (GPP) + graphics processing unit (GPU) consumes more than high-luminosity see-through glasses. This work presents then three main contributions, the first one is the choice and combinations of position and attitude algorithms that fit with the application context. The second one is the architecture of the embedded system, where it is introduced as a fast and simple object processor (OP) optimized for the domain of mobile AR. Finally, the OP implements a new pixel rendering method (incremental pixel shader (IPS)), which is implemented in hardware and takes full advantage of OpenGL ES light model. A GP+OP(s) complete architecture is described and prototyped on field programmable gate-array (FPGA). It includes hardware/software partitioning based on the analysis of application requirements and ergonomics. Keywords Processor Architecture Communication/memory optimization 3D graphics Inertial sensors 3D positioning