Topic
Describing function
About: Describing function is a research topic. Over the lifetime, 1742 publications have been published within this topic receiving 26702 citations.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: In this article, a graphical technique for determining the existence of limit cycles in single-loop feedback systems is presented, based upon the open-loop frequency response data of individual elements, and is applicable to systems containing any number of single-valued, symmetric nonlinearities, separated by low-pass linear elements.
Abstract: This paper presents a graphical technique for determining the existence of limit cycles in single-loop feedback systems. The method is based upon the open-loop frequency response data of the individual elements, and is applicable to systems containing any number of single-valued, symmetric nonlinearities, separated by low-pass linear elements. The approach presented has the advantage of decoupling the effects of the non-linearities which allows us to study separately the effects of each nonlinear element on the overall system. In addition, a criterion is derived which relates the slopes of the input-output curves of the nonlinearities (or the slopes of their describing functions) to the stability of the oscillations. Two examples with analog computer simulations are given.
8 citations
••
01 Sep 2013TL;DR: The main purpose of this study is to predict limit cycles of a dynamic fuzzy control system by combining a stability equation, describing function and parameter plane, and the suppression of the limit cycle by adjusting control parameters.
Abstract: The main purpose of this study is to predict limit cycles of a dynamic fuzzy control system by combining a stability equation, describing function and parameter plane. The stability of a linearized dynamic fuzzy control system is then analyzed using stability equations and the parameter plane method, with the assistance of a describing function method. This procedure identifies the amplitude and frequency of limit cycles that are clearly formed by the dynamic fuzzy controller in the parameter plane. Moreover, the suppression of the limit cycle by adjusting control parameters is proposed. Continuous and sampled-data systems are addressed, and the proposed approach can easily be extended to a fuzzy control system with multiple nonlinearities. Simulations are performed to demonstrate the effectiveness of the proposed scheme.
8 citations
•
01 Jan 2003
8 citations
••
11 Jul 2019
TL;DR: An analytical small-signal model applied for hybrid hysteretic charge (HHC) control has been proposed and analyzed with the advantages over direct frequency control (DFC) and the proposed analytical transfer functions are very useful for the practical power design to achieve good prediction result.
Abstract: In this paper, an analytical small-signal model applied for hybrid hysteretic charge (HHC) control has been proposed and analyzed with the advantages over direct frequency control (DFC). Based on the approach of extended describing function method and average concept, for the first time, the systematical analytical open loop transfer functions from control to output, input to output, output impedance and the closed transfer functions of the overall loop, audio susceptibility and output impedance are proposed and verified through simulation. Additionally, some important physical insights have been extracted, analyzed and verified. Finally, the experiments on a design example of 12 VDC&12 A output power are conducted and verified. It shows that the calculations match well with the results from both the simulation and experiment, which reveals the proposed analytical transfer functions are very useful for the practical power design to achieve good prediction result.
8 citations
••
01 Jan 2018
TL;DR: The paper presents a basic description and examples of the use of so called descriptive functions, allowing analysing the influence of inherent and indispensable components of all mechatronic systems mechanical subsystems so called hard nonlinearities.
Abstract: The paper presents a basic description and examples of the use of so called descriptive functions, allowing analysing the influence of inherent and indispensable components of all mechatronic systems mechanical subsystems so called hard nonlinearities. These parts "causing" in addition to the centrifugal and Coriolis generalized forcesthe nonlinearity of the system, can be analysed by the abovementioned method from the point of view of their origin and the estimation of the basic parameters of their frequent consequences so-called limit cycles. After a short introduction, which introduces and explains describing functions using the example of a nonlinear system taken from the literature, some of the socalled hard nonlinear subsystems (such as the mechanical chain of robots) are shown to be used. The paper is the first part of a more extensive description analysis of nonlinear systems concept using these functions in order to enable analysis and prediction of limit cycles.
8 citations