System identification of a gyroscopic rotor throughout rotor-model-free control using the frequency domain LMS

Abstract

A gyroscopic rotor is controlled and studied. A rotor-model-free control which is based on the transform domain least mean squares algorithm is implemented. An algorithm is proposed which compensates the delay of the transformation for quasi-periodic signals. Experiments show that this algorithm has a positive effect on the first resonance and that it is sufficient to compute the transformation only once per revolution. The rotor-model-free control is then used to excite the system during operation for its identification. A non-parametric model is estimated using two run-outs, one with and one without adaptive feedforward control. Transient phenomena occur after passing the first lightly damped resonance causing a distortion in the estimation. This is remedied by fitting a modal model to the estimation.