Waveform control algorithm for rotational single sheet testers using system identification techniques

In rotational single sheet testers (RSST), the magnetic properties of elect rical steel sheet are measured for well-defined one- or two-dimensional ind uction waveforms over a large frequency range (1-200 Hz). For this task, a new iterative waveform control algorithm is presented. It is based on the r ecursive least squares system identification technique. The modeling of the setup as well as the principles and implementation details of the algorith m are discussed. Simulation and measurement results for alternating sinusoi dal magnetization of the sample are presented. The main advantage of the pr oposed method is that it does not require preliminary information concernin g the properties of the tested material or the measurement setup. The metho d is therefore ideally suited for use in a fully automated measurement syst em. Furthermore, especially for low frequencies (1-10 Hz) the proposed algo rithm exhibits faster convergence compared to previously described methods. (C) 2000 American Institute of Physics. [S0021-8979(00)79108-0].