ADAPTIVE H-INFINITY FILTER - ITS APPLICATION TO STRUCTURAL IDENTIFICATION

adding the function of memory fading for past observation data to the H-infinity filter, the adaptive H-infinity filter was developed for id entifying structural systems with nonstationary dynamic characteristic s. Identification algorithms are proposed for time-varying structural systems in which the velocity and displacement of each floor are avail able for observation, as well as for the case when only the velocity a nd displacement of some floors are available. The Akaike-Bayes informa tion criterion is used to determine the optimal forgetting factor. Ide ntification algorithms that use the adaptive H-infinity and Kalman fil ters are applied to a five-degree of freedom (DOF) linear system with nonstationary dynamic characteristics and to a five-DOF nonlinear stru ctural system. Digital simulation results show that the adaptive H-inf inity filter efficiently traces the time-varying properties of structu ral systems. The behavior of the adaptive H-infinity filter is better than that of the adaptive Kalman filter for identifying a structural s ystem with time-varying dynamic characteristics. The former is more ef ficient and robust for identifying structural systems with nonstationa ry dynamic characteristics.