Coordinate positioning machine

Abstract

A method of recovering a master calibration state of a coordinate positioning machine has a first member that is moveable relative to a second member, wherein the geometry of the machine is characterised by a set of model parameters. The machine is controlled to make point contact between multiple reference surfaces of a tool mounted on the first member and multiple reference surfaces of an artefact mounted on the second member. The separations between these contacting surfaces that would be expected from the current model parameters are determined, and these separations are recorded as a set of master separations. The contacting step is subsequently performed again in respect of at least some of the contacts for which master separations were recorded. At least one of the model parameters is updated to provide a closer correspondence between the expected separations and the master separations.

Dependencies are inferred from the claim text.