Circular and cylindrical profile monitoring considering spatial correlations

Abstract

Geometric specifications are important control objects of mechanical components in modern manufacturing. For instance, circularity and cylindricity are essential indicators of high-precision rotary parts. With an increase in the number of measurement points, traditional statistical process control (SPC) methods cannot be applied in many processes because the measurements are highly correlated. During the past two decades, several studies have focused on profile monitoring. A profile, which describes the relationship between independent and response variables, is suitable for large-scale, complex and high-dimensional data monitoring. However, the issue of spatial correlations in measurement points remains unsolved. Considering spatial correlations, this study focuses on circular and cylindrical profiles and proposes a new method combining a spatial correlation model with control charting. SPC methods are utilized to establish control charts and analyze the control processes. The results of simulation and case study indicate that the proposed method is feasible and effective in monitoring circular and cylindrical profiles and can be extended to other geometric specifications.