Authors:
Tadej Petrič
;
Andrej Gams
and
Leon Žlajpah
Affiliation:
Jožef Stefan Institute, Slovenia
Keyword(s):
Fourier series, Nonlinear dynamical systems, Adaptive frequency oscillators, Imitation, Yo-yo.
Related
Ontology
Subjects/Areas/Topics:
Adaptive Signal Processing and Control
;
Control and Supervision Systems
;
Informatics in Control, Automation and Robotics
;
Modeling, Simulation and Architectures
;
Robotics and Automation
;
Signal Processing, Sensors, Systems Modeling and Control
Abstract:
We present a novel method to obtain the basic frequency of an unknown periodic signal with an arbitrary waveform. The method originates from nonlinear dynamical systems for frequency extraction, which are based on adaptive frequency oscillators in a feedback loop. While using several adaptive frequency oscillators in a loop results in extraction of separate frequency components, our method extracts the basic frequency of
the input signal without any additional logical operations. The proposed method uses a whole Fourier series representation in the feedback loop. In this way it can extract the frequency and the phase of an unknown periodic signal, in real-time, and without any additional signal processing or preprocessing. The method also determines the Fourier series coefficients and can be used for dynamic Fourier series implementation. It can be used for the control of rhythmic robotic tasks, where only the extraction of the fundamental frequency is crucial. This is demonstrated
on a highly nonlinear and dynamic task of playing the robotic yo-yo.
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