Mathematical models for error correction in MScMS-II (Mobile Spatial coordinate Measurement System)

This paper presents three mathematical models for the correction of measurement errors of a prototype system designed for Large Scale Dimensional Metrology (LSDM) applications. The system, developed in the Quality and Industrial Metrology Laboratory of Politecnico di Torino, is based on the principles of photogrammetry and consist of a set of cameras wirelessly connected to a central unit for data elaboration and able to track the position of a hand-held contact probe. Due to its architecture the system is affected by several systematic error sources. This paper addresses some of them: the distortion of the lenses, the dimension of the probe tip and the kinematic of the probe. By means of the implementation of appropriate mathematical correction models, the overall system performance is significantly improved as shown by the proposed tests.