Extended-range hybrid tracker and applications to motion and camera tracking in manufacturing systems

Abstract

Extended- or long-range tracking effectiveness is crucial for the incorporation of mobile robots into manufacturing systems. In this paper, we conceptualize and develop a prototype long-range hybrid tracker based on a combination of a laser tracker and a magnetic tracker and apply the concept to the following two applications: (1) extended-range human motion tracking on factory floors and (2) factory floor object reconstruction from camera images. The easily portable system not only utilizes the strengths of a laser tracker in tracking mobile objects over long ranges in large environments, such as a manufacturing shop floor and the strength of a magnetic tracker to compensate for violation of line-of-sight constraint, but it also reduces the overall cost by reducing the number of expensive beacons required by the laser tracker. The hybrid tracker assists in the development of two concepts: (1) real-time synchronization of human head and hand motion in a manufacturing environment with those of an avatar in a virtual manufacturing environment and (2) a mathematically simpler and practical camera self-calibration technique for the creation of three-dimensional objects in a virtual environment from camera images.