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Describing function

About: Describing function is a research topic. Over the lifetime, 1742 publications have been published within this topic receiving 26702 citations.


Papers
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Proceedings ArticleDOI
01 Jun 2016
TL;DR: The describing function method is used to analyze the behavior of the two methods, the conventional and the super twisting sliding mode control regarding chattering phenomena and the cases are demonstrated where the first order sliding mode Control is more efficient then second order one.
Abstract: In this paper, the describing function method is used to analyze the behavior of the two methods, the conventional and the super twisting sliding mode control regarding chattering phenomena. The cases are demonstrated where the first order sliding mode control is more efficient then second order one. This cases are shown based on analysis and simulation.

46 citations

Proceedings ArticleDOI
TL;DR: In this article, a nonlinear dynamic model of a spur gear pair is coupled with linear finite element models of shafts carrying them, and with discrete models of bearings and disks.
Abstract: This study presents a new nonlinear dynamic model for a gear-shaft-disk-bearing system. A nonlinear dynamic model of a spur gear pair is coupled with linear finite element models of shafts carrying them, and with discrete models of bearings and disks. The nonlinear elasticity term resulting from backlash is expressed by a describing function, and a method developed in previous studies to determine multi harmonic responses of nonlinear multi-degree-of-freedom systems is employed for the solution. The excitations considered in the model are external static torque and internal excitation caused by mesh stiffness variation, gear errors and gear tooth profile modifications. The model suggested and the solution method presented combine the versatility of modeling a shaft-bearing-disk system that can have any configuration without a limitation to the total degree of freedom, with the accuracy of a nonlinear gear mesh interface model that allows to predict jumps and double solutions in frequency response. Thus any single stage gear mesh configuration can be modeled easily and accurately. With the model developed it is possible to calculate dynamic gear loads, dynamic bearing forces, dynamic transmission error and bearing displacements. Theoretical results obtained by using the method suggested are compared with the experimental data available in literature, as well as with the theoretical values calculated by employing a previously developed nonlinear single degree of freedom model.

45 citations

Journal ArticleDOI
TL;DR: In this article, a methodology based on the multifrequency model with describing functions was developed to investigate the phenomenon of beat-frequency oscillation in phase currents, and the influences from the interleaving operation were identified.
Abstract: Under high-frequency repetitive load transients, multiphase voltage regulators suffer from beat-frequency oscillations of the phase currents. To investigate this issue, this paper develops a methodology based on the multifrequency model with describing functions. The phenomenon of beat-frequency oscillation in phase currents is explained. The influences from the interleaving operation are identified. Using peak-current control as an example, the magnitude of beat-frequency oscillations is predicted by a proposed model that considers sideband information. To reduce this oscillation without impacting the voltage regulation, several solutions are proposed. Experimental and simulation results are provided as verification of the analyses and solutions.

45 citations

Journal ArticleDOI
Yingyi1, C Fred1, Paolo1
TL;DR: By designing the external ramp following the proposed design guidelines, the quality factor of the double poles at half of the switching frequency in the control-to-output transfer function can be precisely controlled, helping the feedback loop design to achieve wide control bandwidth and proper damping.
Abstract: This paper proposes a small-signal model for average current mode control based on an equivalent circuit. The model uses a three-terminal equivalent circuit model based on a linearized describing function method to include the feedback effect of the sideband frequency components of the inductor current. The model extends the results obtained in peak current mode control to average current mode control. The proposed small-signal model is accurate up to half switching frequency, predicting the subharmonic instability. The proposed model is verified using SIMPLIS simulation and hardware experiments, which show good agreement with the measurement results. Based on the proposed model, new feedback design guidelines are presented. The proposed design guidelines are compared with several conventional, widely used design criteria. By designing the external ramp following the proposed design guidelines, the quality factor of the double poles at half of the switching frequency in the control-to-output transfer function can be precisely controlled. This helps the feedback loop design to achieve wide control bandwidth and proper damping.

45 citations

Journal ArticleDOI
TL;DR: The Describing Function approach is used to adjust the parameters of fast-oscillations (chattering) caused by the presence offast-actuators in Super-Twisting control loops to minimize the amplitude of oscillations or the average power.

44 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202312
202230
202142
202057
201953
201847