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Extended-or long-range tracking effectiveness is crucial for the automation of 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.

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This paper describes an algorithm for surface reconstruction from a set of scattered three-dimensional points extracted from an image sequence. In this process, additional information (such as location of the viewpoints and the points visible from a particular viewpoint) is available and can be exploited for accurately recovering the shape of the objects portrayed in the images. Initially, the set of points is subjected to a Delaunay triangulation that fills the convex hull of the set of points with disjoint tetrahedra. The key idea of the shape recovery algorithm is to eliminate triangles that obstruct the visibility of points from certain viewpoints, whose locations are known from the image acquisition process. The major contribution of this paper is that we have been able to design an algorithm for surface reconstruction that handles a wide variety of shapes, as opposed to currently existing techniques.