Proposal of edge-area form removal of cylindrical surfaces containing wide dimples by application of various robust processing techniques

Abstract

Surface topography parameters of car engine elements (cylinder liners, piston skirts) are usually calculated after form removal. There are many algorithms dedicated for selection of reference plane in surface topography analysis. However, areal form removal of cylindrical surfaces containing deep or wide valleys (oil pockets, scratches) was not fully recognized when the dimples were edge-situated. Moreover, application of some robust techniques not always provided a reasonable results in areal form removal for surfaces with small (less than dimples diameter value) oil pocket distances. In this paper some digital filtering techniques were proposed for minimization of reference plane distortion when cylindrical elements contained deep and wide valleys with near-edge distribution. It was assumed, that application of commonly used robust techniques caused the distortion of deep or wide near-edge dimples; some of the proposed digital processing algorithms provided a better edge-filtering results.