Periodic signal frequency tracking via a shifted second-order generalized integrator

Second-order generalized integrators have been extensively used for the frequency estimation of periodic input signal. In this paper a novel structure is proposed by considering two additional parameters into the estimation scheme. This results in frequency tracking processes that sensibly attenuate overshooting phenomena affecting the classical approaches. Moreover an opportune choice of such parameters makes the scheme more robust in presence of unaccounted noises. The convergence in case of generic periodic input signal is discussed.