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 (PM) that stores hysteresis behavior. In magnetics it often contains the characterized magnetic properties of 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 PM, a set of test hysteresis loops was reproduced with high accuracy and without artifacts, compared to the commonly used Delaunay-based interpolant.