A study of hybrid control based on H-infinity synthesis technique of active noise control

Studies the hybrid control based on H-infinity synthesis of active noise cancellation for ducts. A method of construction of the augmented matrix in a hybrid ANC system based on state space is presented. First the transfer functions of primary path, secondary path and feedback path of the particular acoustic structure are measured and then normalized to create a state space model for augmented matrix construction. The acoustic feedback problem, which plagues the feedforward control strategies, can be automatically incorporated into the design process. It is shown by computer simulation with white noise source that the method presented in the paper is effective to reduce noise within the range below cut-off frequency with the H-infinity controller