Virtual Sensing of Acoustic Potential Energy Through a Kalman Filter for Active Control of Interior Sound

Abstract

AbstractAn important problem in systems such as aerospace interiors, automobile passenger compartments and other cavities is the control of low frequency interior noise. The present paper addresses an issue related to the feedback control of interior sound through active structural acoustic control approach. Feedback control strategy will be useful when the primary disturbance is broadband or when reference signals cannot be derived in an application. This paper presents development of a strategy for virtual sensing of acoustic potential energy through a Kalman filter, for LQG based active structural acoustic control (ASAC) of sound inside a cavity. The Kalman filter is designed to estimate the states of the cavity-structure subjected to disturbances based on a piezoelectric patch mounted on the structure at a suitable location. The Kalman filter is coupled to a radiation filter to predict the acoustic potential energy inside the cavity that can serve as a cost function in the optimal control. Paper also presents the selection of location of a collocated piezoelectric sensor and actuator pair so that the acoustic potential energy could be sensed effectively. A numerical example of rectangular box cavity backed by flexible plate is considered. The performance of the Kalman filter is evaluated for the various levels of process and measurement noise.KeywordsInterior noiseVirtual sensingActive structural acoustic controlKalman filterRadiation filterAcoustic potential energy