Algorithm for Identification and Observation of the State of Uncertain Harmonic Deviations in Nonlinear Objects

This article examines the problem of observing state variables in nonlinear control objects under conditions of unknown harmonic distortions affecting the output signal. The main goal of the study is to develop an adaptive observation algorithm that allows for the asymptotically accurate estimation of an unmeasured state vector. Unlike existing works, this methodology is based on a two-stage synthesis: identification: amplitude, frequency, and phase indicators of harmonic distortion, auxiliary signals, and adjustable models; observation: a state tracker is constructed based on identified parameters. The approach takes into account that the distortion affects the output signal directly rather than the system input, which further complicates the problem and limits the application of classical tracker methods.