Everett Map Construction for Modeling Static Hysteresis: Delaunay Based Interpolant Versus B-spline Surface

The Everett map is a component used by the Preisach model that stores hysteresis behavior. In magnetics it often contains the characterized magnetic properties of a soft-magnetic material. Fundamentally, the Everett map is created from scattered data points, obtained from a set of magnetic measurements, which must be interpolated to obtain a continuous map. The commonly adopted method to perform the interpolation is based on a Delaunay triangulation computation and subsequent polynomial or B-spline surface fit. However, this approach introduces artifacts in the modeled hysteresis results. Therefore, this work presents an alternative method to construct an artifact free Everett map, by reconstructing a set of measured hysteresis loops with a pre-processing algorithm, and representing the data with a scattered B-spline surface. When applied in the Preisach model, a set of test hysteresis loops was reproduced with high accuracy and without artifacts, compared to the commonly used Delaunay based interpolant.