Design Optimization of a Sensor-Actuator System to Determine Local Variations of Magnetic Permeability

The aim of this work is to optimize the design of a sensor-actuator measurement system for identifying local variations in the magnetic permeability of cut steel sheets. Before the identification problem, i.e. finding the material parameters causing the measurement data, is solved, the design of the measurement setup should first be improved in order to increase the identifiability of the material distribution. For the objective function of the design optimization the Fisher information matrix (FIM) is used, which allows to quantity the amount of information that the measurements carry about the unknown parameters. To evaluate the magnetic field values depending on various design parameters and material distributions, a 2D magneto-static problem is solved by the finite element method. Due to the high numerical effort arising with evaluating the FIM and thus calculating the forward model many times within the optimization procedure, a surrogate model of the sensor-actuator system has been trained in advance and is used to predict the magnetic flux densities.