Title 



Frequency domain, parametric estimation of the evolution of the timevarying dynamics of periodically timevarying systems from noisy inputoutput observations
 
Author 



 
Abstract 



This paper presents a frequency domain, parametric identification method for continuous and discretetime, slow linear timeperiodic (LTP) systems from input output measurements. In this framework, the output as well as the input is allowed to be corrupted by stationary noise (i. e. an errorsinvariables approach is adopted). It is assumed that the system under consideration can be excited by a broadband periodic signal with a userdefined amplitude spectrum (i. e. a multisine), and that the periodicity of the excitation signal Texc, can be synchronized with the periodicity of the timevariation Tsys (i.e. Texc/Tsys is an element of Q), such that the system reaches a steady state (a periodic solution). Tsys, is also known as the pumping period. Once the parametric estimation of the timeevolution of the system parameters has been performed, the system model is evaluated at the level of the instantaneous transfer function (also known as system function, or parametric transfer function), which rigorously characterizes LW systems. If the dynamics of the LTP system are slowly varying or the system is linear parameter varying (LPV), a frozen transfer function approach is provided to easily visualize and assess the quality of the estimated model. To give the estimated quantities a quality label, uncertainty bounds on the modelrelated quantities (such as the timeperiodic (TP) system parameters, the frozen transfer function, the frozen resonance frequency, etc) are derived in this paper as well. Besides, a clear distinction between the instantaneous and the frozen transfer function concept is made, and both can be estimated with the proposed identification scheme. The user decides which transfer function definition suits best its purpose in practice. Finally, the identification algorithm is applied to a simulation example and to real measurements on an extendible robot arm. (C) 2013 Elsevier Ltd. All rights reserved,   
Language 



English
 
Source (journal) 



Mechanical systems and signal processing.  London  
Publication 



London : 2014
 
ISSN 



08883270
 
Volume/pages 



47:12(2014), p. 151174
 
ISI 



000337647200011
 
Full text (Publishers DOI) 


  
