Modeling of Flexible Beam Using System Identification Approach

Abstract

Abstract-This paper presents the modeling of the flexible beam using system identification method. Due to great attention of flexible structures in most applications, vibration becomes the main problem regarding the dynamic of the structures. In controlling vibration, the system necessarily needs a good model. Therefore, the aim of the work described in this paper is to obtain a dynamic model of the flexible beam. By considering a discrete time form for the system, an autoregressive with exogenous input (ARX) model structures was selected. A square wave signal has been used as an input signal to excite the beam in order to collect input-output data from the experiment. Recursive least square (RLS) estimation algorithm is used to estimate the model parameters based on different model orders. The model validation was done by comparing the measured output against the predicted output in terms of the closeness of both outputs via mean square error (MSE) value. The final result shows the model with the 12th order has the lowest error.