MINIMIZATION OF THE MAXIMUM ERROR SIGNAL IN ACTIVE CONTROL

The purpose of this paper is to present a new multichannel adaptive fi ltering algorithm for the active control of single frequency noise in acoustic systems. Most active control systems with multiple error sens ors minimize the sum of the modulus squared output of these sensors. I n this study, an adaptive algorithm is presented that minimizes an alt ernative cost function which, in the limit, is equal to the maximum of the modulus squared values of all the error sensors. The physical con sequences are investigated of minimizing the maximum modulus squared o utput to achieve noise reductions are investigated. An analytical fram ework is developed that covers steady state performance as well as con vergence properties. By means of simulations, the proposed algorithm h as been applied to a linear model of a one-dimensional (1-D) acoustic system and compared with the classical least squares solutions. The pr oposed algorithm is also used in simulations of the control of the pre ssure measured at 32 microphone positions in a room using 16 loudspeak ers, when the room is excited with an 88 Hz pure tone. The results of these simulations show that the observed convergence and steady-state properties agree well with the theoretical predictions. A comparison w ith the least squares solutions leads to the conclusion that the propo sed algorithm leads to a more uniform acoustic field in the enclosure than the classical least squares algorithm.