Effect of errors in the plant model on the performance of algorithms for adaptive feedforward control

The paper presents an investigation into the effects of errors in the assumed plant model on the performance of both single and multichannel adaptive algorithms for the active control of sound and vibration. In the single-channel case the effects of phase errors on the maximum update coefficient and convergence time of the filtered-x LMS algorithm are considered. This involves both analytic results and computer simulations. For the multichannel case a statistical analysis is presented examining the effects of a Gaussian distribution of errors in the assumed plant response on the convergence of the multichannel LMS algorithm. The work includes experimental results from a 32 microphone, 16 loudspeaker active noise control system.