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frequency-domain-identification
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Frequency domain identification of a tapered beam embedded by piezoelectric layer
, Article 2016 International Conference on Advanced Mechatronic Systems, ICAMechS 2016, 30 November 2016 through 3 December 2016 ; 2017 , Pages 312-317 ; 23250682 (ISSN); 9781509053469 (ISBN) ; Ahranjani, F. F ; Kamankesh, Z ; Sharif University of Technology
IEEE Computer Society
2017
Abstract
This study is conducted aiming to identify the dynamics of a tapered beam, embedded by piezoelectric layer. Narrowing the tip of the beam equipped with piezoelectric patches leads to optimize the output power after excitation by the frequency sweep input. An accelerometer is installed on the beam base, which measures the acceleration that is applied to the system. Piezoelectric sensors also measure the generated voltage. The experimental test data is handled through CIFER software, using Fourier transform and Bode plot in the frequency domain, to obtain appropriate transfer functions. MATLAB is used for nonlinear simulation and validation of discrete transfer functions by a set of data that...
Frequency domain identification of the Nomoto model to facilitate Kalman filter estimation and PID heading control of a patrol vessel
, Article Ocean Engineering ; Volume 72 , November , 2013 , Pages 344-355 ; 00298018 (ISSN) ; Ghorbani, M. T ; Sharif University of Technology
2013
Abstract
This paper presents a detailed frequency-domain system identification method applied to identify steering dynamics of a coastal patrol vessel using a data analysis software called CIFER. Advanced features such as the Chirp-Z transform and composite window optimization are used to extract high quality frequency responses. An accurate, robust and linear transfer function model is derived for yaw and roll dynamics of the vessel. To evaluate the accuracy of the identified model, time domain responses from a 45-45 zig-zag test are compared with the responses predicted by the identified model. The identified model shows excellent predictive capability and is well suited for simulation and...
A comprehensive frequency domain identification of a coastal patrol vessel
, Article ICEE 2012 - 20th Iranian Conference on Electrical Engineering, 15 May 2012 through 17 May 2012 ; May , 2012 , Pages 904-909 ; 9781467311489 (ISBN) ; Banazadeh, A ; Sharif University of Technology
2012
Abstract
In This paper detailed frequency-domain system identification method is applied to identify steering dynamics of a naval coastal patrol vessel using a data analysis software tool, called CIFER. Advanced features such as Chirp-Z transform and composite windowing techniques are used to extract high quality frequency responses. An accurate, linear and robust transfer function models are derived for yaw and roll dynamics of the vessel. In addition, to evaluate the accuracy of the identified model, time-domain responses from a 45-45 zig-zag test are compared with the responses predicted by the identified model. The model shows excellent predictive capability that is well suited for simulation...
Development of Rapid Evaluation and Optimization Software for Aircraft Conceptual Design
, M.Sc. Thesis Sharif University of Technology ; Banazadeh, Afshin (Supervisor)
Abstract
Classical methods in aircraft conceptual aircraft design have some deficiencies in such as low accuracy in aerodynamic derivatives estimation and incapability of verifying flight handling quality. Moreover, application of experimental equations and dependence on statistical data are other drawbacks of classical methods which are accounted as big challenges in development of unusual aircrafts. In this research, a comprehensive, rapid and practical software is developed in order to promote the conceptual aircraft design. This software provides a platform to perform various tasks such as aerodynamic measurement, nonlinear simulation, system identification and optimization simultaneously. In...
Theoretical and Experimental Analysis of Dynamic Model of a Single-Blade Aerial Vehicle Based on Frequency Domain Identification
, M.Sc. Thesis Sharif University of Technology ; Saghafi, Fariborz (Supervisor) ; Banazadeh, Afshin (Supervisor)
Abstract
The main goal of this work is to estimate the linear transfer function of a single-blade VTOL aerial vehicle, the so-called Monocopter.At first, a prototype of this vehicle is designed and built based on the previously gathered information. The complexity and high manufacturing cost of the first prototype has forced us to build one other simple and cost-effective vehicle. A complete electronic board for data-logging has also designed and built. Many flight test has been carried out and recorded output data are processed by CIFER and MATLAB software in order to identify the dynamic model of the vehicle. The results are presented in different forms
Development of Maneuvering Control Model for a Catamaran using System Identification Method and Experimental Tests
, M.Sc. Thesis Sharif University of Technology ; Seif, Mohammad Saeed (Supervisor)
Abstract
The current research is one of the sections of the project for the design and construction of an Unmanned Surface vehicle (USV) , with the goal of extracting the dynamic model of the float using experimental tests. Initially, a literature review on system identification methods and the development of a dynamic model of the float has been conducted. Following that, the process of constructing and equipping a Catamaran platform for conducting tests and collecting suitable data for extracting the dynamic model has been described. Subsequently, tests have been conducted on the constructed float.Using the data obtained from the experimental tests, an artificial neural network has been employed to...
Identification of the equivalent linear dynamics and controller design for an unmanned underwater vehicle
, Article Ocean Engineering ; Volume 139 , 2017 , Pages 152-168 ; 00298018 (ISSN) ; Seif, M. S ; Khodaei, M. J ; Rezaie, M ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
This paper investigates the applicability of frequency-domain system identification technique to achieve the equivalent linear dynamics of an autonomous underwater vehicle for control design purposes. Frequency response analysis is performed on the nonlinear and coupled dynamics of the vehicle, utilizing the CIFER® software to extract a reduced-order model in the form of equivalent transfer functions. Advanced features such as chirp-z transform, composite window optimization, and conditioning are employed to achieve high quality and accurate frequency responses. A particular frequency-sweep input is implemented to the nonlinear simulation model to achieve pole-zero transfer functions for yaw...
Identification of dynamic properties of dams using system identification techniques and real earthquake excitations
, Article 9th US National and 10th Canadian Conference on Earthquake Engineering 2010, Including Papers from the 4th International Tsunami Symposium, Toronto, ON, 25 July 2010 through 29 July 2010 ; Volume 9 , 2010 , Pages 6985-6996 ; 9781617388446 (ISBN) ; Meshkat, A ; Sharif University of Technology
2010
Abstract
Investigation of the dynamic characteristics of an existing structure system based on field tests is of practical significance, since it can be employed in the field of examining construction quality, validating or improving analytical finite element structural models, or conducting damage assessment. The main purpose of this study is to investigate the dynamic characteristics of dams using the seismic response data. Whereas, in the process of frequency domain identification of dam properties, frequency response function (FRF) plays the most important role, evaluating the corresponding parameters with better accuracy has always been desirable. Therefore, a comparison was made between some...
Generalization of order distribution concept use in the fractional order system identification
, Article Signal Processing ; Volume 90, Issue 7 , July , 2010 , Pages 2243-2252 ; 01651684 (ISSN) ; Haeri, M ; Sharif University of Technology
2010
Abstract
In this paper, the order distribution concept in the frequency domain identification has been extended to include fractional order systems having poles and zeros simultaneously. The existing nonlinear optimization problem appeared when both poles and zeros, is are changed to a quadratic problem that can be solved using least squares algorithms. To collect the required data, system is excited by a multi sine input signal with appropriately selected frequencies. Then a nonparametric identification in frequency domain is accomplished to calculate the empirical transfer function estimate (ETFE). This estimate is then used to implement the frequency domain identification on all defined members of...
Identifiability of fractional order systems using input output frequency contents
, Article ISA Transactions ; Volume 49, Issue 2 , Apr , 2010 , Pages 207-214 ; 00190578 (ISSN) ; Haeri, M ; Tavazoei, M. S ; Sharif University of Technology
2010
Abstract
In this paper, issues related to the identifiability of a fractional order system having its input and output frequency contents are discussed. The effects of the commensurate order α in the identifiability of the model structure and model parameters are analytically studied. It is shown that both identifiabilities (model structure and model parameters) are reduced remarkably for smaller values of α. This phenomenon is observed even though the input signals are rich enough and system belongs to the model set. Our understanding is that the problem arises since differences among different members of the model set fall beyond the practically recognizable precision range. The issue is more...