Fixed-gain/adaptive Control for Simultaneous Rejection of Broadband and Sinusoidal Disturbances

In this paper we experimentally investigate the feasibility of using a hybrid fixed-gain/adaptive control architecture for simultaneous rejection of broadband and sinusoidal disturbances. The motivation for this study comes from active noise control (ANC) applications in which the disturbance has both broadband and sinusoidal components, for example, wind noise and engine noise in an aircraft cabin. The advantage of this approach is that it improves performance while reducing real-time computational load. The experiment is carried out on a three dimensional acoustic space contained in a steel drum, on which speakers and microphones are mounted as actuators and sensors respectively. A fixed-gain H<z optimal (LQG) controller is used to attenuate the broadband component of the noise while a low-order extended ARMARKOV adaptive controller (EAAC) is used to attenuate a tonal disturbance of unknown frequency.