A comparison of the eigensystem realization algorithm and the Q-Markov COVER

Abstract

Two time domain modal analysis methods, the Eigensystem Realization Algorithm and the QMarkov COVER, are compared and contrasted. It is shown that, under certain conditions, the Eigensystem Realization Algorithm and the QMarkov COVER yield similar realizations of structural systems. Both methods use different solutions for the system dynamic matrix (the A matrix). When applied to simulated data, the reconstruction error is nearly the same. But when applied to real data, the Eigensystem Realization Algorithm is consistently, but only marginally, more accurate. This may be due to the balanced realization used in the Eigensystem Realization Algorithm. However, the Q-Markov COVER can be implemented much faster for large order data sets because of the particular structure of the algorithm.