Patent ID: 7568373
Filing Date: 2009-08-04
Classification: G01B

Abstract:
1. A method of calibrating an articulating probe head, the articulating probe head being mounted on an arm of a coordinate positioning apparatus, in which a surface sensing device mounted on the articulating probe head is moved into a position-sensing relationship with an artefact and a position reading taken, the method comprising: determining true measurements of an artefact by measuring the artefact with no relative movement between the surface sensing device and the arm of the coordinate positioning apparatus; measuring the artefact whose true measurements have been determined, wherein at least one motor of the articulating probe head is driven to provide relative movement between the surface sensing device and the arm of the coordinate positioning apparatus; generating an error function or map corresponding to the difference between the measured artefact and the true measurements of the artefact; measuring subsequent workpieces wherein at least one motor of the articulating probe head is driven to provide relative movement between the surface sensing device and the arm of the coordinate measuring apparatus; and correcting subsequent workpieces by using the generated error function or map.