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
01 May 2007
TL;DR: The BIMBO identification method can be used for the online identification of the digital filter in a sigma-delta modulator's loop and this parameter estimation method only requires the knowledge of the bit stream at the modulator output.
Abstract: We show how the BIMBO identification method can be used for the online identification of the digital filter in a sigma-delta modulator's loop. This parameter estimation method only requires the knowledge of the bit stream at the modulator output. This approach does not rely on an approximation of the comparator (such as additive white noise or describing function approximation). Moreover, it requires no amplitude measurement, as opposed to most other methods, and, thus, it involves no additional electronics: it is therefore very economical to implement it practically. The method is described from a theoretical point of view and an experimental validation is given.
6 citations
TL;DR: In this paper, the existence of limit cycles and undesirable equilibrium points in nonlinear, MIMO control systems in the presence of uncertainties is studied using the dual describing function method.
6 citations
TL;DR: The nonlinear actuator model with parameters identified from dedicated tests is experimentally validated allowing for an accurate prediction of the expected gust load alleviation performance, and the impact of the individual nonlinearities on the overall closed-loop performance is quantified.
Abstract: In this paper, the effect of nonlinear actuator dynamics on the performance of an active load alleviation system for an experimental flexible wing is studied. Common nonlinearities such as backlash or rate limits are considered for the control surface actuator. An aeroelastic simulation model of a flexible wing with control surface is being used. With this, a parameter study is carried out to quantify the impact of the individual nonlinearities on the overall closed-loop performance by means of describing functions. Finally, the nonlinear actuator model with parameters identified from dedicated tests is experimentally validated allowing for an accurate prediction of the expected gust load alleviation performance.
6 citations
26 Jun 2010
TL;DR: In this article, compensators for the twisting and sub-optimal algorithms are designed aiming at the increase of the open-loop gain of the system with respect to the averaged variables (at low frequencies).
Abstract: In this paper, compensators for the Twisting and Sub-Optimal algorithms are designed The compensation is aimed at the increase of the open-loop gain of the system with respect to the averaged variables (at low frequencies) achieved through the mechanism of the increase of the equivalent gains kn of the controller nonlinearities The describing function method is used for the development of the system model An example of design and simulations are presented
6 citations
14 Jun 2006
TL;DR: In this article, the second-order sliding mode observer dynamics were analyzed in the frequency domain, based on the describing function method and the concept of the equivalent gains of nonlinear functions of the super-twisting algorithm.
Abstract: The second order sliding mode observer dynamics are analyzed in the frequency domain. The so-called super-twisting algorithm is utilized for generating the second-order sliding mode in the observer dynamical system. The frequency response of the actuator dynamics is obtained and used as a characteristic of the observer. The analysis proposed is based on the describing function method and the concept of the equivalent gains of nonlinear functions of the super-twisting algorithm.
6 citations