One-parameter robust global frequency estimator for slowly varying amplitude and noisy oscillations

Robust online estimation of oscillation frequency belongs to classical problems system identification and adaptive control. The given harmonic signal can be noisy with varying amplitude at the same time, as in case damped vibrations. A novel robust frequency-estimation algorithm is proposed here, motivated by existing globally convergent estimator. advantage estimator requiring one design parameter only being against measurement noise initial conditions. proven global convergence also allows for slowly amplitudes, which useful applications oscillations or additionally shaped signals. analysis simple relies on an averaging theory periodic Our results show exponential rate, depends, analytically, sought frequency, adaptation gain amplitude. Numerical experimental examples demonstrate robustness efficiency signals noise.