Feedforward multiple harmonic control for periodic disturbance rejection

The paper discusses compensation of several sinusoidal disturbance signals entering the system simultaneously. The disturbances may have different frequencies, amplitudes and phases. A modification of the well-known LMS algorithm is proposed, which makes a direct feedforward compensation algorithm possible. It is demonstrated that the problems of the standard LMS algorithm, when several disrurbance frequencies enter the system simultaneously, can now be avoided with a multidimensional LMS algorithm. The performance is demonstrated by extensive simulations.