A study of online plant modelling methods for active control of sound and vibration

Active control systems using the filtered-x algorithm require plant models to describe the relations between the secondary sources and the error sensors. For practical applications online plant modelling may be required if the environment changes significantly. In this study, two dominant methods for online plant modelling are compared by simulation.

One approach yields convincing results in terms of converge, but sometimes the steady state performance can be suboptimal, because the plant models are erroneous. Another approach gives results close to the theoretically optimal for a broadband random disturbance, whereas the results obtained for sinusoidal disturbances are less impressive.