MODEL-BASED TOPOGRAPHY CHARACTERIZATION OF MACHINED SURFACES IN 3 DIMENSIONS

An integrated model-based approach has been proposed for the topograph y characterisation of surfaces in three dimensions. The approach is th e integration of advantages of several techniques, such as areal autoc orrelation functions in the identification of surface features and the diagnostics of model adequacy; spectral analysis in the understanding of frequency components of surfaces. The approach is based on the Wor ld theorem, which justifies in theory the decomposition of a stationar y surface into deterministic and stochastic components. The determinis tic constituent (as a periodic lay structure for most machined surface s) may be modelled by a Fourier series. In contrast, the stochastic co nstituent may be represented by a spatial model. The developed model-b ased system, using the technique of data compression, has been applied successfully to the investigation of 3D topography features of some m achined surfaces.