Scanning errors identification using touch trigger probe head

Abstract

The objective of this research presented in this paper is to generate mathematical model, which combines ball tip radius error and small tilt of the stylus to determine translational motion (in two directions) of the stylus ball centre, due to the surface slope. In simple two-dimensional mathematical model is described one error. Second model is based on 3D-mathematical model, which is a basis to determine (and plot) translational movement of the stylus ball according to surface slope. Scanning process on freeform surface with touch trigger probe head could not be performed very accurately, due to a number of reasons related to the stylus ball and trigger probe head errors. Translational movement of the stylus ball centre at any slope can be shown only on 4D?6D-graphs, which does not exist. Such mathematical error might be a basis to create mathematical compensation error model. Because in literature, we did not find such mathematical model to determine translational motion (in two directions) of the stylus ball centre, the contribution of the conducted research is observed in one possible view of two types of systematic errors, which may occur during surface scanning process with touch trigger probe head. [Received 13 October 2006; Accepted 3 March 2007]