Patent attributes
A coordinate positioning arm includes: a base end and a head end; a drive frame for moving the head end relative to the base end; and a metrology frame for measuring a position and orientation of the head end relative to the base end. The drive frame includes a plurality of drive axes arranged in series between the base end and the head end. The metrology frame includes a plurality of metrology axes arranged in series between the base end and the head end. The metrology frame is adapted and arranged to be substantially separate and/or independent from the drive frame, for example by supporting the metrology frame substantially only at the base end and head end and by providing the metrology frame with sufficient degrees of freedom (via the metrology axes) to avoid creating an additional constraint between the metrology frame and the drive frame.
