Abstract: Disclosed is a highly accurate articulated coordinate measuring machine, comprising a revolute joint, comprising a circular encoder wheel, having an axis of rotation; a plurality of marks disposed around at least a portion of the circumference of the encoder wheel; bearing means for supporting the encoder wheel, while permitting free rotation of the encoder wheel about the wheel's axis of rotation; and a sensor, rigidly attached to the bearing means, for detecting the motion of at least some of the marks as the encoder wheel rotates; a probe arm, having a proximal end rigidly attached to the encoder wheel, and having a distal end with a probe tip attached thereto; and coordinate processing means, operatively connected to the sensor, for converting the output of the sensor into a set of cylindrical coordinates representing the position of the probe tip relative to a reference cylindrical coordinate system.

Abstract: Disclosed is a system and method for independently evaluating the spatial positional performance of a machine having a movable member, comprising an articulated coordinate measuring machine comprising: a first revolute joint; a probe arm, having a proximal end rigidly attached to the first joint, and having a distal end with a probe tip attached thereto, wherein the probe tip is pivotally mounted to the movable machine member; a second revolute joint; a first support arm serially connecting the first joint to the second joint; and coordinate processing means, operatively connected to the first and second revolute joints, for calculating the spatial coordinates of the probe tip; means for kinematically constraining the articulated coordinate measuring machine to a working surface; and comparator means, in operative association with the coordinate processing means and with the movable machine, for comparing the true position of the movable machine member, as measured by the true position of the probe tip, with

Abstract: A solid model is constructed from surface point data that represent layers of an object. The model is represented as the level set of an implicit function that is fitted to the surface point data. In the two-dimensional application of the technique, a Delaunay triangulation is performed for each layer. In this step, surface points are connected to form Delaunay triangles; the data points are the vertices of the Delaunay triangles. A circumcircle is then created around each Delaunay triangle, passing through the three vertices of the triangle. To decimate the circumcircle data, overlapping circumspheres are merged according to a merging criterion. A pseudo-union of implicit functions for the reduced number of circumcircles provides an initial implicit function for the layer. Errors in the implicit function are substantially reduced by optimizing the position and/or radii of the circumcircles.