System Identification Algorithm for Computing the Modal Parameters of Linear Mechanical Systems

Abstract

Abstract:The goal of this investigation is to construct a computational procedure for identifying the modal parameters of linear mechanical systems. The methodology employed in the paper is based on the Eigensystem Realization Algorithm implemented in conjunction with the Observer/Kalman Filter Identification method (ERA/OKID). This method represents an effective and efficient system identification numerical procedure based on the time domain. The algorithm developed in this work is tested by means of numerical experiments on a full-car vehicle model. To this end, the modal parameters necessary for the design of active and semi-active suspension systems are obtained for the vehicle system considered as an illustrative example. In order to analyze the performance of the methodology developed in this investigation, the system identification numerical procedure was tested considering two case studies, namely a full state measurement and an incomplete state measurement. As expected, the numerical results found for the identified dynamical model showed a good agreement with the modal parameters of the mechanical system model. Furthermore, numerical results demonstrated that the proposed method has good performance considering a scenario in which the signal-to-noise ratio of the input and output measurements is relatively high. The method developed in this paper can be effectively used for solving important engineering problems such as the design of control systems for road vehicles.

Design of a Large Deployable Reflector Opening System

“…At this point, several simulations of the deployment phase have been carried out to find the spring stiffness and damping coefficient of the dampers, imposing an opening time of the mechanism of about 30 s as a constraint. The integration method and the values of the parameters used for the simulation have been adapted for the specific case of contacts as suggested in References [23][24][25][26]. The selection of the stiffnesses of the torsion springs was influenced by the maximum torsion angle, which must be greater than 177 • , and by the diameter of the pin (8 mm) on which the spring is to be positioned.…”

Output-Only Parameters Identification of Earthquake-Excited Building Structures with Least Squares and Input Modification Process

“…To date, a number of vibration-based system identification and damage detection methods have been developed, and review articles with different emphases can be also found [2][3][4]. In general, structural parameters identification can be performed in three different paradigms: (i) time domain (e.g., [5][6][7][8][9][10]), (ii) frequency domain (e.g., [11][12][13][14]), and (iii) time-frequency domain (e.g., [15][16][17]).…”

Vibration-Based Experimental Identification of the Elastic Moduli Using Plate Specimens of the Olive Tree

“…As it is known, the wood has a behavior orthotropic and therefore it is necessary to evaluate the different characteristic moduli for these types of materials, for which it is necessary to use mathematical models more complex to simulate its behaviour. We will refer to the theory of the orthotropic plates broadly treated in the literature [37][38][39][40].…”