Abstract: The mathematical model of the error separation technique (EST) of the rotary workpiece based on the three-probes cylindrical method is established, and the method to solve the model is given. The computer simulation on the three-probe EST is also carried out. Several contrastive experiments of the on-line measurement are carried out on a semi-automatic grinding machine (MB1332A). The workpieces used in the experiments are measured by TALYROND 262 geometrical error measurement instrument. The results of these experiments successfully verify that the theory and mathematical models are correct. The contrast of the measuring results in these experiments proves that the three-probe method can realize the complete separation of all kinds of errors basically and this method is applicable to on-line measurement of workpieces and high online measurement accuracy can be obtained.

Key words: 3-probe, Cylindricity, Error separation, Roundness