Minimizing the effect of out of bandwidth dynamics in the models of reverberant systems that arise in modal analysis: implications on spatial H∞ control

The assumed modes modelling of structures and acoustic systems results in infinite-dimensional models. For control design purposes, these models are simplified by removing higher frequency modes which lie out of the bandwidth of interest. Truncation can considerably perturb the zeros of the truncated model. The paper suggests a method of minimizing the effect of removed higher order modes on the spatial low-frequency dynamics of the truncated model by adding a spatial zero frequency term to the low order model of the system. The paper also studies implications of this approach on spatial H_∞ control of reverberant systems