Development of a touch probe based on five-dimensional force/torque transducer for coordinate measuring machine (CMM)

Systematic errors due to the pre-travel variation and the probe tip shape are irreducible to the traditional touch trigger probing systems. This paper describes the development of a probing system based on five-dimensional force/torque transducer for coordinate measuring machines. The compensation for pre-travel variation is accomplished through the five-dimensional force/torque information acquired by the integrated transducer and the stiffness matrix of the stylus. From the relationship between the obtained force/torque information and the geometrical shape equation, coordinates of the exact contact point immune from the contact error are acquired. After calibration, the combined measurement uncertainty is estimated to be less than ±0.3 μm.