Statistical Evaluation Method for Cylindricity Deviation Using Local Least Squares Cylinder

Accurately evaluating cylindricity deviation is the most important requirement for the quality analysis and control of cylindrical products in modern industrial manufacturing processes. The cylindricity deviation of a whole cylinder is usually evaluated with measured points from the target surface. In practice, there are many local intrinsic characteristics that can be related to defects or manufacturing errors, and some precision cylindrical workpieces such as large bearings and rollers are very sensitive to the local cylindricity quality. Hence, it is necessary to evaluate and analyze the local cylindricity variation. In previous works, few methods have focused on the deviation evaluation of local patches of the measured workpieces, and variation of local characteristics could not be directly reflected. In this paper, we propose a new statistical evaluation method for cylindricity deviation using local least squares reference cylinder, which not only evaluates the local and global cylindricity deviations, but also presents deviation change features. This paper illustrates the theoretical basis of the statistical evaluation method, provides the evaluation operation process and parameters, and finally demonstrates the accuracy and feasibility of the proposed method according to the experimental results. The proposed method can be effectively used to provide a reliable verification of the product quality and to analyze the error sources in manufacturing and inspection phases.