Algorithm for evaluating the noise immunity of the method of determining the parameters of oscillations of the blades of turbine based on nonlinear approximation of the signals of primary converters

The paper proposes a new implementation of discrete-phase method allowing to determine the parameters of turbomachinery blades oscillations by analyzing the waveform distortion of primary transducer. Oscillations of the blades, both natural and forced, result in uneven speed of passage of the blades near the sensor, which leads to a distortion of the informational signal. Further analysis of the distorted signal is performing by non-linear approximation methods by which approximating function parameters are found to describe the law of blade oscillations - amplitude, frequency and initial phase. The analysis is carried out for different values of the signal / noise ratio. Statistical analysis of a series of samples of the distorted signal allows to estimate the error in determining the parameters of the blade oscillations.