Calibration of a contact probe for micro-nano CMM

In order to obtain the transformation model between the three output signals of the contact probe of the Micro/nano coordinate measuring machine (CMM) and the three-dimensional space coordinates of the probe ball, a calibration model based on Taylor expansion is proposed. The probe consists of a 3-DOF coaxial beam sensor with the displacement measurement based on the principle of Michelson interference and two angles measurement based on the autocollimation principle, a suspension mechanism and a ruby ball. According to the relationship between the coordinate vector of the ball centre and the output signal vector of the probe, the calibration model based on Taylor expansion is proposed. The reliability of the model is verified by experiment tests. Performance tests show that the maximum calibration error of the model is 92 nm. The results demonstrate the calibration model features the feasibility and the validity, which can meet the calibration requirement of the Micro/nano CMM.