Analysis of Methods for Estimation of Machine Workpiece Roundness

One of the parameters most commonly used in the control of workpieces complex form is roundness. Increasing requirements to the workpieces form accuracy determines the relevance of improving methods and instruments for the control of form surfaces. The paper presents the analysis of three methods of roundness calculation by using Maximum Inscribed Circle, Least Squares Circle, Minimum Zone Tolerance Circle. A Matlab software have been developed for this application package. The input data consisted of the coordinates, obtained by the control the external surface of the rollers and the inner surface of the raceways ring bearing on the precision roundness measurement instrument, the toroidal profile of the raceways bearing rings on the Coordinate Measuring Machine. Based on these studies it was revealed that in all cases, the best result is provided at the use of the Minimum Zone Tolerance Circle from the mean value and standard deviation of roundness.