USING AUTO-CROSS SPECTRUM and FUZZY EKF for MODAL ANALYSIS of MIMO SYSTEMS

Using EKF (Extended Kalman Filter) for modal analysis of MIMO systems is a new method which has been proposed lately. In this paper some developments on mentioned method have been proposed. First development is using auto and cross-spectrum of forces and responses which have improved accuracy of modal parameters’ estimation. Secondly, fuzzy logic has been used for developing EKF process which makes rapid and correct convergence of estimation. The proposed method has been used on a 3DOF system with different number of forces and its applied positions. The Accuracy of estimations of modal parameters has been compared between proposed method and previous work. The conclusion is that the accuracy of new method has been increased very much and the accuracy of this paper and previous method has been decreased by increasing of applied forces.