Measurement errors analysis for a position estimator for self-sensing magnetic levitation systems

In this work, a measurement error analysis for a position estimator for self-sensing magnetic levitation systems is shown. The analysis is based on the position estimation algorithm proposed in [3, 4], which is set up by a least squares identification of the inductance and a suitable averaging. By means of a mathematical model the main idea of the estimation strategy is shortly outlined and it is shown that the influence of the electric resistance and of the duty-cycle as well as of the motion of the levitated object can be approximately eliminated. For multiplicative and additive current and voltage measurement errors a detailed analysis of the resulting position estimation error is presented. Additionally, a position variance estimation based on the assumption of normal distributed measurements is shown. The theoretical results are validated by means of simulation results.