Model-free frequency domain iterative active sound and vibration control

In this paper, a model-free iterative feedback tuning method is presented to tune a frequency domain controller for a set of narrow-band disturbances. A single control problem with multiple tones of the disturbance is split into a set of parallel control problems. Due to the representation in the frequency domain, there are only control amplitude and phase to be tuned for each tone. Tuning is performed through a sequence of experiments which enables the calculation of a model-free gradient of a quadratic cost function. The number of experiments at each iterative step is R×S+1, where R is the number of controls signals and S is the number of output signals. Results on a laboratory active sound control system are shown. The example demonstrates the practical effectiveness of the method.