Probe-radius compensation for 3D data points in reverse engineering

The very first step in the process of reverse engineering is to acquire data points by measuring the points on the surface of an object. The fineness and correctness of the data significantly affect the quality of the final CAD model as well as the machined workpiece. However, the point data measured with a typical coordinate measuring machine (CMM) have often been the data of the probe center rather than those of the object’s surface, and this poses a great challenge in reverse engineering. This paper, thus, aims to resolve a practical problem in reverse engineering: what is the best way to compensate the measured data points with the value of probe radius? An approach to connecting corresponding points between every two adjacent measuring trajectories is proposed to formulate triangular meshes directly from the massive data points, so as to determine the normal vector of each point for probe-radius compensation. In the paper, the methodology and algorithms to implement the formulation of triangular meshes will be presented in detail with expository examples.